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Sample records for flash memory devices

  1. Some Improvements in Utilization of Flash Memory Devices

    Science.gov (United States)

    Gender, Thomas K.; Chow, James; Ott, William E.

    2009-01-01

    Two developments improve the utilization of flash memory devices in the face of the following limitations: (1) a flash write element (page) differs in size from a flash erase element (block), (2) a block must be erased before its is rewritten, (3) lifetime of a flash memory is typically limited to about 1,000,000 erases, (4) as many as 2 percent of the blocks of a given device may fail before the expected end of its life, and (5) to ensure reliability of reading and writing, power must not be interrupted during minimum specified reading and writing times. The first development comprises interrelated software components that regulate reading, writing, and erasure operations to minimize migration of data and unevenness in wear; perform erasures during idle times; quickly make erased blocks available for writing; detect and report failed blocks; maintain the overall state of a flash memory to satisfy real-time performance requirements; and detect and initialize a new flash memory device. The second development is a combination of hardware and software that senses the failure of a main power supply and draws power from a capacitive storage circuit designed to hold enough energy to sustain operation until reading or writing is completed.

  2. NAND flash memory technologies

    CERN Document Server

    Aritome, Seiichi

    2016-01-01

    This book discusses basic and advanced NAND flash memory technologies, including the principle of NAND flash, memory cell technologies, multi-bits cell technologies, scaling challenges of memory cell, reliability, and 3-dimensional cell as the future technology. Chapter 1 describes the background and early history of NAND flash. The basic device structures and operations are described in Chapter 2. Next, the author discusses the memory cell technologies focused on scaling in Chapter 3, and introduces the advanced operations for multi-level cells in Chapter 4. The physical limitations for scaling are examined in Chapter 5, and Chapter 6 describes the reliability of NAND flash memory. Chapter 7 examines 3-dimensional (3D) NAND flash memory cells and discusses the pros and cons in structure, process, operations, scalability, and performance. In Chapter 8, challenges of 3D NAND flash memory are dis ussed. Finally, in Chapter 9, the author summarizes and describes the prospect of technologies and market for the fu...

  3. Characterizations of MoTiO{sub 5} flash memory devices with post-annealing

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Chyuan Haur [Chang Gung University, No. 1, University Rd, Puli, Nantou County 54561, Taiwan, ROC (China); Chen, Hsiang, E-mail: hchen@ncnu.edu.tw [National Chi Nan University, No. 1, University Rd, Puli, Nantou County 54561, Taiwan, ROC (China); Chen, Su Zhien [Chang Gung University, No. 1, University Rd, Puli, Nantou County 54561, Taiwan, ROC (China); Chen, Yu Jie; Chu, Yu Cheng [National Chi Nan University, No. 1, University Rd, Puli, Nantou County 54561, Taiwan, ROC (China)

    2014-11-03

    In this study, high-K MoTiO{sub 5} dielectrics were applied as charge trapping layers in fabricated metal-oxide-high-K MoTiO{sub 5}-oxide-Si-type memory devices. Among the applied MoTiO{sub 5} trapping layer treatment conditions, annealing at 900 °C yielded devices that exhibited superior memory performance, such as a larger memory window and faster programming/erasing speed. Multiple material analyses, namely X-ray diffraction, X-ray photoelectron spectroscopy, and atomic force microscopy, confirmed that annealing at 900 °C can improve the material quality as a result of crystallization. The fabricated MoTiO{sub 5}-based memory devices show potential for future commercial memory device applications. - Highlights: • MoTiO5-based flash memories have been fabricated. • MoTiO5 trapping layers could be formed by co-sputtering. • MoTiO5 layers with annealing exhibited a good memory performance. • Multiple material analyses confirm that annealing enhanced crystallization.

  4. Chemical-Vapor-Deposited Graphene as Charge Storage Layer in Flash Memory Device

    Directory of Open Access Journals (Sweden)

    W. J. Liu

    2016-01-01

    Full Text Available We demonstrated a flash memory device with chemical-vapor-deposited graphene as a charge trapping layer. It was found that the average RMS roughness of block oxide on graphene storage layer can be significantly reduced from 5.9 nm to 0.5 nm by inserting a seed metal layer, which was verified by AFM measurements. The memory window is 5.6 V for a dual sweep of ±12 V at room temperature. Moreover, a reduced hysteresis at the low temperature was observed, indicative of water molecules or −OH groups between graphene and dielectric playing an important role in memory windows.

  5. Coding for flash memories

    OpenAIRE

    Yaakobi, Eitan

    2011-01-01

    Flash memories are, by far, the most important type of non -volatile memory in use today. They are employed widely in mobile, embedded, and mass-storage applications, and the growth in this sector continues at a staggering pace. Moreover, since flash memories do not suffer from the mechanical limitations of magnetic disk drives, solid- state drives have the potential to upstage the magnetic recording industry in the foreseeable future. The research goal of this dissertation is the discovery o...

  6. The influence of Ti doping and annealing on Ce2Ti2O7 flash memory devices

    Science.gov (United States)

    Kao, Chyuan Haur; Chen, Su Zhien; Luo, Yang; Chiu, Wang Ting; Chiu, Shih Wei; Chen, I. Chien; Lin, Chan-Yu; Chen, Hsiang

    2017-02-01

    In this research, a CeO2 film with Ti doping was used as a trapping layer in metal oxide high-K-oxide-Si (MOHOS)-type memory devices. Since incorporation of Ti atoms into the film could fix dangling bonds and defects, the Ce2Ti2O7 trapping layer with annealing treatment could have a larger memory window and a faster programming/erasing speed. To confirm the origin, multiple material analyses indicate that annealing at an appropriate temperature and Ti doping could enhance crystallization. The Ce2Ti2O7-based memory device is promising for future industrial flash memory applications.

  7. PIYAS-Proceeding to Intelligent Service Oriented Memory Allocation for Flash Based Data Centric Sensor Devices in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Sanam Shahla Rizvi

    2009-12-01

    Full Text Available Flash memory has become a more widespread storage medium for modern wireless devices because of its effective characteristics like non-volatility, small size, light weight, fast access speed, shock resistance, high reliability and low power consumption. Sensor nodes are highly resource constrained in terms of limited processing speed, runtime memory, persistent storage, communication bandwidth and finite energy. Therefore, for wireless sensor networks supporting sense, store, merge and send schemes, an efficient and reliable file system is highly required with consideration of sensor node constraints. In this paper, we propose a novel log structured external NAND flash memory based file system, called Proceeding to Intelligent service oriented memorY Allocation for flash based data centric Sensor devices in wireless sensor networks (PIYAS. This is the extended version of our previously proposed PIYA [1]. The main goals of the PIYAS scheme are to achieve instant mounting and reduced SRAM space by keeping memory mapping information to a very low size of and to provide high query response throughput by allocation of memory to the sensor data by network business rules. The scheme intelligently samples and stores the raw data and provides high in-network data availability by keeping the aggregate data for a longer period of time than any other scheme has done before. We propose effective garbage collection and wear-leveling schemes as well. The experimental results show that PIYAS is an optimized memory management scheme allowing high performance for wireless sensor networks.

  8. Atomic-layer deposited IrO2 nanodots for charge-trap flash-memory devices

    International Nuclear Information System (INIS)

    Choi, Sangmoo; Cha, Young-Kwan; Seo, Bum-Seok; Park, Sangjin; Park, Ju-Hee; Shin, Sangmin; Seol, Kwang Soo; Park, Jong-Bong; Jung, Young-Soo; Park, Youngsoo; Park, Yoondong; Yoo, In-Kyeong; Choi, Suk-Ho

    2007-01-01

    Charge-trap flash- (CTF) memory structures have been fabricated by employing IrO 2 nanodots (NDs) grown by atomic-layer deposition. A band of isolated IrO 2 NDs of about 3 nm lying almost parallel to Si/SiO 2 interface is confirmed by transmission electron microscopy and x-ray photoelectron spectroscopy. The memory device with IrO 2 NDs shows much larger capacitance-voltage (C-V) hysteresis and memory window compared with the control sample without IrO 2 NDs. After annealing at 800 deg. C for 20 min, the ND device shows almost no change in the width of C-V hysteresis and the ND distribution. These results indicate that the IrO 2 NDs embedded in SiO 2 can be utilized as thermally stable, discrete charge traps, promising for metal oxide-ND-based CTF memory devices

  9. Endurance degradation and lifetime model of p-channel floating gate flash memory device with 2T structure

    Science.gov (United States)

    Wei, Jiaxing; Liu, Siyang; Liu, Xiaoqiang; Sun, Weifeng; Liu, Yuwei; Liu, Xiaohong; Hou, Bo

    2017-08-01

    The endurance degradation mechanisms of p-channel floating gate flash memory device with two-transistor (2T) structure are investigated in detail in this work. With the help of charge pumping (CP) measurements and Sentaurus TCAD simulations, the damages in the drain overlap region along the tunnel oxide interface caused by band-to-band (BTB) tunneling programming and the damages in the channel region resulted from Fowler-Nordheim (FN) tunneling erasure are verified respectively. Furthermore, the lifetime model of endurance characteristic is extracted, which can extrapolate the endurance degradation tendency and predict the lifetime of the device.

  10. Nanoscale memory devices

    International Nuclear Information System (INIS)

    Chung, Andy; Deen, Jamal; Lee, Jeong-Soo; Meyyappan, M

    2010-01-01

    This article reviews the current status and future prospects for the use of nanomaterials and devices in memory technology. First, the status and continuing scaling trends of the flash memory are discussed. Then, a detailed discussion on technologies trying to replace flash in the near-term is provided. This includes phase change random access memory, Fe random access memory and magnetic random access memory. The long-term nanotechnology prospects for memory devices include carbon-nanotube-based memory, molecular electronics and memristors based on resistive materials such as TiO 2 . (topical review)

  11. In2Ga2ZnO7 oxide semiconductor based charge trap device for NAND flash memory

    Science.gov (United States)

    Hwang, Eun Suk; Kim, Jun Shik; Jeon, Seok Min; Lee, Seung Jun; Jang, Younjin; Cho, Deok-Yong; Hwang, Cheol Seong

    2018-04-01

    The programming characteristics of charge trap flash memory device adopting amorphous In2Ga2ZnO7 (a-IGZO) oxide semiconductors as channel layer were evaluated. Metal-organic chemical vapor deposition (MOCVD) and RF-sputtering processes were used to grow a 45 nm thick a-IGZO layer on a 20 nm thick SiO2 (blocking oxide)/p++-Si (control gate) substrate, where 3 nm thick atomic layer deposited Al2O3 (tunneling oxide) and 5 nm thick low-pressure CVD Si3N4 (charge trap) layers were intervened between the a-IGZO and substrate. Despite the identical stoichiometry and other physicochemical properties of the MOCVD and sputtered a-IGZO, a much faster programming speed of MOCVD a-IGZO was observed. A comparable amount of oxygen vacancies was found in both MOCVD and sputtered a-IGZO, confirmed by x-ray photoelectron spectroscopy and bias-illumination-instability test measurements. Ultraviolet photoelectron spectroscopy analysis revealed a higher Fermi level (E F) of the MOCVD a-IGZO (∼0.3 eV) film than that of the sputtered a-IGZO, which could be ascribed to the higher hydrogen concentration in the MOCVD a-IGZO film. Since the programming in a flash memory device is governed by the tunneling of electrons from the channel to charge trapping layer, the faster programming performance could be the result of a higher E F of MOCVD a-IGZO.

  12. In2Ga2ZnO7oxide semiconductor based charge trap device for NAND flash memory.

    Science.gov (United States)

    Hwang, Eun Suk; Kim, Jun Shik; Jeon, Seok Min; Lee, Seung Jun; Jang, Younjin; Cho, Deok-Yong; Hwang, Cheol Seong

    2018-04-01

    The programming characteristics of charge trap flash memory device adopting amorphous In 2 Ga 2 ZnO 7 (a-IGZO) oxide semiconductors as channel layer were evaluated. Metal-organic chemical vapor deposition (MOCVD) and RF-sputtering processes were used to grow a 45 nm thick a-IGZO layer on a 20 nm thick SiO 2 (blocking oxide)/p ++ -Si (control gate) substrate, where 3 nm thick atomic layer deposited Al 2 O 3 (tunneling oxide) and 5 nm thick low-pressure CVD Si 3 N 4 (charge trap) layers were intervened between the a-IGZO and substrate. Despite the identical stoichiometry and other physicochemical properties of the MOCVD and sputtered a-IGZO, a much faster programming speed of MOCVD a-IGZO was observed. A comparable amount of oxygen vacancies was found in both MOCVD and sputtered a-IGZO, confirmed by x-ray photoelectron spectroscopy and bias-illumination-instability test measurements. Ultraviolet photoelectron spectroscopy analysis revealed a higher Fermi level (E F ) of the MOCVD a-IGZO (∼0.3 eV) film than that of the sputtered a-IGZO, which could be ascribed to the higher hydrogen concentration in the MOCVD a-IGZO film. Since the programming in a flash memory device is governed by the tunneling of electrons from the channel to charge trapping layer, the faster programming performance could be the result of a higher E F of MOCVD a-IGZO.

  13. Nonvolatile Flash Memory Devices Using CeO2 Nanocrystal Trapping Layer for Two-Bit per Cell Applications

    Science.gov (United States)

    Yang, Shao-Ming; Chien, Chao-Hsin; Huang, Jiun-Jia; Lei, Tan-Fu

    2007-06-01

    In this study, we demonstrated the characteristics of nonvolatile silicon oxide nitride oxide silicon (SONOS)-type memories using cerium oxide (CeO2) nanocrystals as a charge storage agent. We observed that the shape of the formed CeO2 nanocrystals is nearly spherical and that their size is almost similar identical to their high density of 5× 1011 cm-2. Such CeO2 nanocrystals were formed by depositing a thin CeO2 film of ca. 2-3 nm thickness using an evaporater gun system and then rapid thermal annealing (RTA) in O2 ambient at 900 °C for 1 min. The fabricated memory devices show good electrical properties in terms of a sufficiently large memory window (>2 V), program/erase (P/E) speed (0.1/1 ms), retention time up to 104 s with only 5% charge loss, and endurance after 105 cycles with small memory window narrowing and two-bit operation. These properties suggest that the nonvolatile SONOS-type memories with the CeO2 nanocrystal trapping agent can be applied in future flash memories.

  14. FPGA Flash Memory High Speed Data Acquisition

    Science.gov (United States)

    Gonzalez, April

    2013-01-01

    The purpose of this research is to design and implement a VHDL ONFI Controller module for a Modular Instrumentation System. The goal of the Modular Instrumentation System will be to have a low power device that will store data and send the data at a low speed to a processor. The benefit of such a system will give an advantage over other purchased binary IP due to the capability of allowing NASA to re-use and modify the memory controller module. To accomplish the performance criteria of a low power system, an in house auxiliary board (Flash/ADC board), FPGA development kit, debug board, and modular instrumentation board will be jointly used for the data acquisition. The Flash/ADC board contains four, 1 MSPS, input channel signals and an Open NAND Flash memory module with an analog to digital converter. The ADC, data bits, and control line signals from the board are sent to an Microsemi/Actel FPGA development kit for VHDL programming of the flash memory WRITE, READ, READ STATUS, ERASE, and RESET operation waveforms using Libero software. The debug board will be used for verification of the analog input signal and be able to communicate via serial interface with the module instrumentation. The scope of the new controller module was to find and develop an ONFI controller with the debug board layout designed and completed for manufacture. Successful flash memory operation waveform test routines were completed, simulated, and tested to work on the FPGA board. Through connection of the Flash/ADC board with the FPGA, it was found that the device specifications were not being meet with Vdd reaching half of its voltage. Further testing showed that it was the manufactured Flash/ADC board that contained a misalignment with the ONFI memory module traces. The errors proved to be too great to fix in the time limit set for the project.

  15. The influence of Ti doping and annealing on Ce{sub 2}Ti{sub 2}O{sub 7} flash memory devices

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Chyuan Haur [Department of Electronic Engineering, Chang Gung University, No. 259, Wenhua 1st Rd., Guishan Dist., Taoyuan City 33302, Taiwan, ROC (China); Kidney Research Center, Department of Nephrology, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan, ROC (China); Department of Electronic Engineering, Ming Chi University of Technology, Taiwan, ROC (China); Chen, Su Zhien [Department of Electronic Engineering, Chang Gung University, No. 259, Wenhua 1st Rd., Guishan Dist., Taoyuan City 33302, Taiwan, ROC (China); Kidney Research Center, Department of Nephrology, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan, ROC (China); Luo, Yang; Chiu, Wang Ting; Chiu, Shih Wei; Chen, I Chien [Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, No. 1, University Rd., Puli, Nantou Country 54561, Taiwan, ROC (China); Lin, Chan-Yu [Kidney Research Center, Department of Nephrology, Chang Gung Memorial Hospital, Chang Gung University, College of Medicine, Taoyuan, Taiwan, ROC (China); Chen, Hsiang, E-mail: hchen@ncnu.edu.tw [Department of Applied Materials and Optoelectronic Engineering, National Chi Nan University, No. 1, University Rd., Puli, Nantou Country 54561, Taiwan, ROC (China)

    2017-02-28

    Highlights: • Ce{sub 2}Ti{sub 2}O{sub 7} flash memories have been fabricated. • Material quality can be improved by annealing. • The memory performance can be enhanced by Ti doping. • Ti doping and annealing can reinforce crystallization. - Abstract: In this research, a CeO{sub 2} film with Ti doping was used as a trapping layer in metal oxide high-K-oxide-Si (MOHOS)-type memory devices. Since incorporation of Ti atoms into the film could fix dangling bonds and defects, the Ce{sub 2}Ti{sub 2}O{sub 7} trapping layer with annealing treatment could have a larger memory window and a faster programming/erasing speed. To confirm the origin, multiple material analyses indicate that annealing at an appropriate temperature and Ti doping could enhance crystallization. The Ce{sub 2}Ti{sub 2}O{sub 7}-based memory device is promising for future industrial flash memory applications.

  16. A Durable Flash Memory Search Tree

    OpenAIRE

    Clay III, James; Wortman, Kevin

    2012-01-01

    We consider the task of optimizing the B-tree data structure, used extensively in operating systems and databases, for sustainable usage on multi-level flash memory. Empirical evidence shows that this new flash memory tree, or FM Tree, extends the operational lifespan of each block of flash memory by a factor of roughly 27 to 70 times, while still supporting logarithmic-time search tree operations.

  17. Influence of source coupling on the programming and degradation mechanisms of split-gate flash memory devices

    Science.gov (United States)

    Huang, K.-C.; Fang, Y.-K.; Yaung, D.-N.; Chen, C.-W.; Sung, H.-C.; Kuo, D.; Wang, C. S.; Liang, M.-S.

    1999-12-01

    In this paper, the mechanism of programming operation considering the source-to-floating gate coupling ratio (SCR) in split-gate source-side injected flash memory has been discussed and experimentally demonstrated. The effects of SCR on the programming performance and cycling endurance have also been investigated in detail. The experimental results indicate that the cell with higher SCR possesses a higher programming speed. Under the same programming speed, the higher-SCR cell shows larger cycling endurance compared to lower-SCR cell.

  18. Non Volatile Flash Memory Radiation Tests

    Science.gov (United States)

    Irom, Farokh; Nguyen, Duc N.; Allen, Greg

    2012-01-01

    Commercial flash memory industry has experienced a fast growth in the recent years, because of their wide spread usage in cell phones, mp3 players and digital cameras. On the other hand, there has been increased interest in the use of high density commercial nonvolatile flash memories in space because of ever increasing data requirements and strict power requirements. Because of flash memories complex structure; they cannot be treated as just simple memories in regards to testing and analysis. It becomes quite challenging to determine how they will respond in radiation environments.

  19. GaAs metal-oxide-semiconductor based non-volatile flash memory devices with InAs quantum dots as charge storage nodes

    International Nuclear Information System (INIS)

    Islam, Sk Masiul; Chowdhury, Sisir; Sarkar, Krishnendu; Nagabhushan, B.; Banerji, P.; Chakraborty, S.; Mukherjee, Rabibrata

    2015-01-01

    Ultra-thin InP passivated GaAs metal-oxide-semiconductor based non-volatile flash memory devices were fabricated using InAs quantum dots (QDs) as charge storing elements by metal organic chemical vapor deposition technique to study the efficacy of the QDs as charge storage elements. The grown QDs were embedded between two high-k dielectric such as HfO 2 and ZrO 2 , which were used for tunneling and control oxide layers, respectively. The size and density of the QDs were found to be 5 nm and 1.8×10 11 cm −2 , respectively. The device with a structure Metal/ZrO 2 /InAs QDs/HfO 2 /GaAs/Metal shows maximum memory window equivalent to 6.87 V. The device also exhibits low leakage current density of the order of 10 −6 A/cm 2 and reasonably good charge retention characteristics. The low value of leakage current in the fabricated memory device is attributed to the Coulomb blockade effect influenced by quantum confinement as well as reduction of interface trap states by ultra-thin InP passivation on GaAs prior to HfO 2 deposition

  20. SOLID-STATE STORAGE DEVICE FLASH TRANSLATION LAYER

    DEFF Research Database (Denmark)

    2017-01-01

    Embodiments of the present invention include a method for storing a data page d on a solid-state storage device, wherein the solid-state storage device is configured to maintain a mapping table in a Log-Structure Merge (LSM) tree having a C0 component which is a random access memory (RAM) device...... and a C1 component which is a flash-based memory device. Methods comprise: writing the data page d at a physical storage page having physical storage page address P in the storage device in response to receiving a write request to store the data page d at a logical storage page having a logical storage...

  1. Memory characteristics of cobalt-silicide nanocrystals embedded in HfO2 gate oxide for nonvolatile nanocrystal flash devices

    Science.gov (United States)

    Kim, JooHyung; Yang, JungYup; Lee, JunSeok; Hong, JinPyo

    2008-01-01

    Cobalt-silicide (CoSi2) nanocrystals (NCs) were investigated for use in charge storage for metal oxide semiconductor (MOS) devices with thin HfO2 tunneling and control oxide layers. CoSi2 NCs were synthesized by exposure of Co /Si/HfO2 tunneling oxide/Si stacks to an external UV laser. Observations from transmission electron microscopy and x-ray photoelectron spectroscopy clearly confirm the formation of CoSi2 NCs and the values of Co-Si bonding energies that are shifted 0.3eV from original values, respectively. The CoSi2 NCs in MOS devices exhibited a large memory window of 3.4V as well as efficient programming/erasing speeds, good retention, and endurance times.

  2. Multi-Level Bitmap Indexes for Flash Memory Storage

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kesheng; Madduri, Kamesh; Canon, Shane

    2010-07-23

    Due to their low access latency, high read speed, and power-efficient operation, flash memory storage devices are rapidly emerging as an attractive alternative to traditional magnetic storage devices. However, tests show that the most efficient indexing methods are not able to take advantage of the flash memory storage devices. In this paper, we present a set of multi-level bitmap indexes that can effectively take advantage of flash storage devices. These indexing methods use coarsely binned indexes to answer queries approximately, and then use finely binned indexes to refine the answers. Our new methods read significantly lower volumes of data at the expense of an increased disk access count, thus taking full advantage of the improved read speed and low access latency of flash devices. To demonstrate the advantage of these new indexes, we measure their performance on a number of storage systems using a standard data warehousing benchmark called the Set Query Benchmark. We observe that multi-level strategies on flash drives are up to 3 times faster than traditional indexing strategies on magnetic disk drives.

  3. Transparent Flash Memory using Single Ta2O5 Layer for both Charge Trapping and Tunneling Dielectrics

    KAUST Repository

    Hota, Mrinal Kanti

    2017-06-08

    We report reproducible multibit transparent flash memory in which a single solution-derived Ta2O5 layer is used simultaneously as charge trapping and tunneling layer. This is different from conventional flash cells, where two different dielectric layers are typically used. Under optimized programming/erasing operations, the memory device shows excellent programmable memory characteristics with a maximum memory window of ~10 V. Moreover, the flash memory device shows a stable 2-bit memory performance, good reliability, including data retention for more than 104 sec and endurance performance for more than 100 cycles. The use of a common charge trapping and tunneling layer can simplify advanced flash memory fabrication.

  4. Flash memory in embedded Java programs

    DEFF Research Database (Denmark)

    Korsholm, Stephan Erbs

    This paper introduces a Java execution environment with the capability for storing constant heap data in Flash, thus saving valuable RAM. The extension is motivated by the structure of three industrial applications which demonstrate the need for storing constant data in Flash on small embedded...... devices. The paper introduces the concept of host initialization of constant data to prepare a Flash image of constant data that can be kept outside the heap during runtime. The concept is implemented in an interpreter based Java execution environment....

  5. Flash memory in embedded Java programs

    DEFF Research Database (Denmark)

    Korsholm, Stephan Erbs

    2011-01-01

    This paper introduces a Java execution environment with the capability for storing constant heap data in Flash, thus saving valuable RAM. The extension is motivated by the structure of three industrial applications which demonstrate the need for storing constant data in Flash on small embedded...... devices. The paper introduces the concept of host initialization of constant data to prepare a Flash image of constant data that can be kept outside the heap during runtime. The concept is implemented in an interpreter based Java execution environment....

  6. Recovery of Flash Memories for Reliable Mobile Storages

    Directory of Open Access Journals (Sweden)

    Daesung Moon

    2010-01-01

    Full Text Available As the mobile appliance is applied to many ubiquitous services and the importance of the information stored in it is increased, the security issue to protect the information becomes one of the major concerns. However, most previous researches focused only on the communication security, not the storage security. Especially, a flash memory whose operational characteristics are different from those of HDD is used increasingly as a storage device for the mobile appliance because of its resistance to physical shock and lower power requirement. In this paper, we propose a flash memory management scheme targeted for guaranteeing the data integrity of the mobile storage. By maintaining the old data specified during the recovery window, we can recover the old data when the mobile appliance is attacked. Also, to reduce the storage requirement for the recovery, we restrict the number of versions to be copied, called Degree of Integrity (DoI. Especially, we consider both the reclaim efficiency and the wear leveling which is a unique characteristic of the flash memory. Based on the performance evaluation, we confirm that the proposed scheme can be acceptable to many applications as a flash memory management scheme for improving data integrity.

  7. Flash drive memory apparatus and method

    Science.gov (United States)

    Hinchey, Michael G. (Inventor)

    2010-01-01

    A memory apparatus includes a non-volatile computer memory, a USB mass storage controller connected to the non-volatile computer memory, the USB mass storage controller including a daisy chain component, a male USB interface connected to the USB mass storage controller, and at least one other interface for a memory device, other than a USB interface, the at least one other interface being connected to the USB mass storage controller.

  8. From silicon to organic nanoparticle memory devices.

    Science.gov (United States)

    Tsoukalas, D

    2009-10-28

    After introducing the operational principle of nanoparticle memory devices, their current status in silicon technology is briefly presented in this work. The discussion then focuses on hybrid technologies, where silicon and organic materials have been combined together in a nanoparticle memory device, and finally concludes with the recent development of organic nanoparticle memories. The review is focused on the nanoparticle memory concept as an extension of the current flash memory device. Organic nanoparticle memories are at a very early stage of research and have not yet found applications. When this happens, it is expected that they will not directly compete with mature silicon technology but will find their own areas of application.

  9. Flash memories economic principles of performance, cost and reliability optimization

    CERN Document Server

    Richter, Detlev

    2014-01-01

    The subject of this book is to introduce a model-based quantitative performance indicator methodology applicable for performance, cost and reliability optimization of non-volatile memories. The complex example of flash memories is used to introduce and apply the methodology. It has been developed by the author based on an industrial 2-bit to 4-bit per cell flash development project. For the first time, design and cost aspects of 3D integration of flash memory are treated in this book. Cell, array, performance and reliability effects of flash memories are introduced and analyzed. Key performance parameters are derived to handle the flash complexity. A performance and array memory model is developed and a set of performance indicators characterizing architecture, cost and durability is defined.   Flash memories are selected to apply the Performance Indicator Methodology to quantify design and technology innovation. A graphical representation based on trend lines is introduced to support a requirement based pr...

  10. Highly scalable 3-D NAND-NOR hybrid-type dual bit per cell flash memory devices with an additional cut-off gate

    International Nuclear Information System (INIS)

    Cho, Seongjae; Shim, Wonbo; Park, Ilhan; Kim, Yoon; Park, Byunggook

    2010-01-01

    In this work, a nonvolatile memory (NVM) device of novel structure in 3 dimensions is introduced, and its operation physics is validated. It is based on a pillar structure in which two identical storage nodes are located for dual-bit operation. The two storage nodes on neighboring pillars are controlled by using one common control gate so that the space between silicon pillars can be further reduced. For compatibility with conventional memory operations, an additional cut-off gate is constructed under the common control gate. This is considered as the ultimate form for a 3-D nonvolatile memory device based on a double-gate structure. The underlying physics is explained, and the operational schemes are validated in various aspects by using a numerical device simulation. Also, critical issues in device design for higher reliability are discussed.

  11. Space Qualified, Radiation Hardened, Dense Monolithic Flash Memory, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Space Micro proposes to build a radiation hardened by design (RHBD) flash memory, using a modified version of our RH-eDRAM Memory Controller to solve all the single...

  12. Performance enhancement in p-channel charge-trapping flash memory devices with Si/Ge super-lattice channel and band-to-band tunneling induced hot-electron injection

    International Nuclear Information System (INIS)

    Liu, Li-Jung; Chang-Liao, Kuei-Shu; Jian, Yi-Chuen; Wang, Tien-Ko; Tsai, Ming-Jinn

    2013-01-01

    P-channel charge-trapping flash memory devices with Si, SiGe, and Si/Ge super-lattice channel are investigated in this work. A Si/Ge super-lattice structure with extremely low roughness and good crystal structure is obtained by precisely controlling the epitaxy thickness of Ge layer. Both programming and erasing (P/E) speeds are significantly improved by employing this Si/Ge super-lattice channel. Moreover, satisfactory retention and excellent endurance characteristics up to 10 6 P/E cycles with 3.8 V memory window show that the degradation on reliability properties is negligible when super-lattice channel is introduced. - Highlights: ► A super-lattice structure is proposed to introduce more Ge content into channel. ► Super-lattice structure possesses low roughness and good crystal structure. ► P-channel flash devices with Si, SiGe, and super-lattice channel are investigated. ► Programming/erasing speeds are significantly improved. ► Reliability properties can be kept for device with super-lattice channel

  13. Performance enhancement in p-channel charge-trapping flash memory devices with Si/Ge super-lattice channel and band-to-band tunneling induced hot-electron injection

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Li-Jung [Department of Engineering and System Science, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan, ROC (China); Chang-Liao, Kuei-Shu, E-mail: Lkschang@ess.nthu.edu.tw [Department of Engineering and System Science, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan, ROC (China); Jian, Yi-Chuen; Wang, Tien-Ko [Department of Engineering and System Science, National Tsing Hua University, 101, Sec. 2, Kuang-Fu Rd., Hsinchu 30013, Taiwan, ROC (China); Tsai, Ming-Jinn [Electronics and Opto-electronics Research Laboratories, Industrial Technology Research Institute, 195, Sec. 4, Chung Hsing Rd., Chutung, Hsinchu 31040, Taiwan, ROC (China)

    2013-04-30

    P-channel charge-trapping flash memory devices with Si, SiGe, and Si/Ge super-lattice channel are investigated in this work. A Si/Ge super-lattice structure with extremely low roughness and good crystal structure is obtained by precisely controlling the epitaxy thickness of Ge layer. Both programming and erasing (P/E) speeds are significantly improved by employing this Si/Ge super-lattice channel. Moreover, satisfactory retention and excellent endurance characteristics up to 10{sup 6} P/E cycles with 3.8 V memory window show that the degradation on reliability properties is negligible when super-lattice channel is introduced. - Highlights: ► A super-lattice structure is proposed to introduce more Ge content into channel. ► Super-lattice structure possesses low roughness and good crystal structure. ► P-channel flash devices with Si, SiGe, and super-lattice channel are investigated. ► Programming/erasing speeds are significantly improved. ► Reliability properties can be kept for device with super-lattice channel.

  14. Transparent Flash Memory Using Single Ta2O5Layer for Both Charge-Trapping and Tunneling Dielectrics.

    Science.gov (United States)

    Hota, Mrinal K; Alshammari, Fwzah H; Salama, Khaled N; Alshareef, Husam N

    2017-07-05

    We report reproducible multibit transparent flash memory in which a single solution-derived Ta 2 O 5 layer is used simultaneously as a charge-trapping layer and a tunneling layer. This is different from conventional flash memory cells where two different dielectric layers are typically used. Under optimized programming/erasing operations, the memory device shows excellent programmable memory characteristics with a maximum memory window of ∼10.7 V. Moreover, the flash memory device shows a stable 2-bit memory performance and good reliability, including data retention for more than 10 4 s and endurance performance for more than 100 cycles. The use of a common charge-trapping and tunneling layer can simplify the fabrication of advanced flash memories.

  15. Memristive behavior in a junctionless flash memory cell

    International Nuclear Information System (INIS)

    Orak, Ikram; Ürel, Mustafa; Dana, Aykutlu; Bakan, Gokhan

    2015-01-01

    We report charge storage based memristive operation of a junctionless thin film flash memory cell when it is operated as a two terminal device by grounding the gate. Unlike memristors based on nanoionics, the presented device mode, which we refer to as the flashristor mode, potentially allows greater control over the memristive properties, allowing rational design. The mode is demonstrated using a depletion type n-channel ZnO transistor grown by atomic layer deposition (ALD), with HfO 2 as the tunnel dielectric, Al 2 O 3 as the control dielectric, and non-stoichiometric silicon nitride as the charge storage layer. The device exhibits the pinched hysteresis of a memristor and in the unoptimized device, R off /R on ratios of about 3 are presented with low operating voltages below 5 V. A simplified model predicts R off /R on ratios can be improved significantly by adjusting the native threshold voltage of the devices. The repeatability of the resistive switching is excellent and devices exhibit 10 6  s retention time, which can, in principle, be improved by engineering the gate stack and storage layer properties. The flashristor mode can find use in analog information processing applications, such as neuromorphic computing, where well-behaving and highly repeatable memristive properties are desirable

  16. Review on Non-Volatile Memory with High-k Dielectrics: Flash for Generation Beyond 32 nm.

    Science.gov (United States)

    Zhao, Chun; Zhao, Ce Zhou; Taylor, Stephen; Chalker, Paul R

    2014-07-15

    Flash memory is the most widely used non-volatile memory device nowadays. In order to keep up with the demand for increased memory capacities, flash memory has been continuously scaled to smaller and smaller dimensions. The main benefits of down-scaling cell size and increasing integration are that they enable lower manufacturing cost as well as higher performance. Charge trapping memory is regarded as one of the most promising flash memory technologies as further down-scaling continues. In addition, more and more exploration is investigated with high -k dielectrics implemented in the charge trapping memory. The paper reviews the advanced research status concerning charge trapping memory with high -k dielectrics for the performance improvement. Application of high -k dielectric as charge trapping layer, blocking layer, and tunneling layer is comprehensively discussed accordingly.

  17. Review on Non-Volatile Memory with High-k Dielectrics: Flash for Generation Beyond 32 nm

    Directory of Open Access Journals (Sweden)

    Chun Zhao

    2014-07-01

    Full Text Available Flash memory is the most widely used non-volatile memory device nowadays. In order to keep up with the demand for increased memory capacities, flash memory has been continuously scaled to smaller and smaller dimensions. The main benefits of down-scaling cell size and increasing integration are that they enable lower manufacturing cost as well as higher performance. Charge trapping memory is regarded as one of the most promising flash memory technologies as further down-scaling continues. In addition, more and more exploration is investigated with high-k dielectrics implemented in the charge trapping memory. The paper reviews the advanced research status concerning charge trapping memory with high-k dielectrics for the performance improvement. Application of high-k dielectric as charge trapping layer, blocking layer, and tunneling layer is comprehensively discussed accordingly.

  18. Abstract Specification of the UBIFS File System for Flash Memory

    Science.gov (United States)

    Schierl, Andreas; Schellhorn, Gerhard; Haneberg, Dominik; Reif, Wolfgang

    Today we see an increasing demand for flash memory because it has certain advantages like resistance against kinetic shock. However, reliable data storage also requires a specialized file system knowing and handling the limitations of flash memory. This paper develops a formal, abstract model for the UBIFS flash file system, which has recently been included in the Linux kernel. We develop formal specifications for the core components of the file system: the inode-based file store, the flash index, its cached copy in the RAM and the journal to save the differences. Based on these data structures we give an abstract specification of the interface operations of UBIFS and prove some of the most important properties using the interactive verification system KIV.

  19. GeckoFTL: Scalable Flash Translation Techniques For Very Large Flash Devices

    DEFF Research Database (Denmark)

    Dayan, Niv; Bonnet, Philippe; Idreos, Stratos

    2016-01-01

    thereby harming performance and device lifetime. In this paper, we identify a key component of the metadata called the Page Validity Bitmap (PVB) as the bottleneck. PVB is used by the garbage-collectors of state-of-the-art FTLs to keep track of which physical pages in the device are invalid. PVB...... Gecko. Logarithmic Gecko is similar to an LSM-tree in that it first logs updates and later reorganizes them to ensure fast and scalable access time. Relative to the baseline of storing PVB in flash, Logarithmic Gecko enables cheaper updates at the cost of slightly more expensive garbage......-collection queries. We show that this is a good trade-off because (1) updates are intrinsically more frequent than garbage-collection queries to page validity metadata, and (2) flash writes are more expensive than flash reads. We demonstrate analytically and empirically through simulation that GeckoFTL achieves a 95...

  20. Objective hot flashes are negatively related to verbal memory performance in midlife women.

    Science.gov (United States)

    Maki, Pauline M; Drogos, Lauren L; Rubin, Leah H; Banuvar, Suzanne; Shulman, Lee P; Geller, Stacie E

    2008-01-01

    To test the hypothesis that hot flashes specifically relate to verbal memory performance by examining the relationship between objective hot flashes and cognitive test performance in women with moderate to severe vasomotor symptoms. In an observational study, 29 midlife women (mean age, 53 y) with moderate to severe hot flashes provided measures of objective hot flashes with an ambulatory hot flash monitor, subjective hot flashes with a diary and questionnaire, and objective measures of verbal memory and other cognitive functions with standardized neuropsychological tests. The mean number of objective hot flashes was 19.5 per day (range, 6 to 35), including 15.3 (range, 6 to 35) during waking hours and 4.2 (range, 0 to 9) during sleep. The mean sensitivity (ie, subjective detection of objectively measured hot flashes) was 60%. Regression analyses revealed that total number of objective hot flashes, sleep duration, and verbal knowledge were significant predictors of delayed verbal memory. Verbal fluency correlated positively with objective daytime hot flashes. Hot flashes did not predict performance on any of the other secondary cognitive measures (ie, attention, working memory, visual memory), although poor sleep predicted worse performance on several outcome measures. Highly symptomatic women underreport the number of objective hot flashes that they experience by 43%. Verbal memory performance relates significantly to the objective number of hot flashes women experience but not to the number of hot flashes that they report. These findings suggest that physiological factors related to hot flashes, rather than psychological factors, predict poorer verbal memory function.

  1. Inadvertently programmed bits in Samsung 128 Mbit flash devices: a flaky investigation

    Science.gov (United States)

    Swift, G.

    2002-01-01

    JPL's X2000 avionics design pioneers new territory by specifying a non-volatile memory (NVM) board based on flash memories. The Samsung 128Mb device chosen was found to demonstrate bit errors (mostly program disturbs) and block-erase failures that increase with cycling. Low temperature, certain pseudo- random patterns, and, probably, higher bias increase the observable bit errors. An experiment was conducted to determine the wearout dependence of the bit errors to 100k cycles at cold temperature using flight-lot devices (some pre-irradiated). The results show an exponential growth rate, a wide part-to-part variation, and some annealing behavior.

  2. Charge-trap flash memory using zirconium-nitride-based memristor switches

    Science.gov (United States)

    Kim, Hee-Dong; Kim, Kyeong Heon; An, Ho-Myoung; Kim, Tae Geun

    2014-11-01

    Charge-trap flash (CTF) memory using a zirconium nitride (ZrN)-based memristor switch (MRS) is demonstrated for next-generation nonvolatile memory. This device consists of a metal/MRS/nitride/oxide/silicon (M/MRS/N/O/S) structure so that electrical transport via the ZrN-based MRS layer can be utilized. Compared to previous oxide materials used as conduction paths, the proposed CTF device with a ZrN-based MRS exhibits a faster program/erase switching speed (20 ns/7 ns), along with comparable endurance and retention properties.

  3. Modeling of apparent activation energy and lifetime estimation in NAND flash memory

    International Nuclear Information System (INIS)

    Lee, Kyunghwan; Shin, Hyungcheol; Kang, Myounggon; Hwang, Yuchul

    2015-01-01

    Misunderstanding apparent activation energy (E aa ) can cause serious error in lifetime predictions. In this paper, the E aa is investigated for sub 20 nm NAND flash memory. In a high-temperature (HT) regime, the interface trap (N it ) recovery mechanism has the greatest impact on the charge loss. However, the values of E aa and E a(Nit) have a wide difference. Also, the lifetime of the device cannot be estimated by the Arrhenius model due to the E aa roll-off behavior. For the first time, we reveal the origin of abnormal characteristics on E aa and derive a mathematical formula for E aa as a function of each E a(mechanism) in NAND flash memory. Using the proposed E aa equation, the accurate lifetime for the device is estimated. (paper)

  4. Charge trap flash memory using ferroelectric materials as a blocking layer

    Science.gov (United States)

    Seo, Yujeong; An, Ho-Myoung; Yeong Song, Min; Geun Kim, Tae

    2012-04-01

    In this paper, we propose a charge-trap flash memory device using a ferroelectric material, Sr0.7Bi2.3Nb2O9 (SBN), with spontaneous polarization as a blocking layer. This device consists of metal/SBN/nitride/oxide/silicon and has an advantage in the carrier injection into the nitride from the silicon due to polarization charges formed in the ferroelectric material. Compared to conventional metal/oxide/nitride/oxide/silicon memory devices, the proposed devices showed a larger memory window (7 V), faster program/erase (P/E) speeds (100/500 μs), and higher endurance (105 P/E cycles) with comparable retention properties.

  5. Architectural and Integration Options for 3D NAND Flash Memories

    Directory of Open Access Journals (Sweden)

    Rino Micheloni

    2017-08-01

    Full Text Available Nowadays, NAND Flash technology is everywhere, since it is the core of the code and data storage in mobile and embedded applications; moreover, its market share is exploding with Solid-State-Drives (SSDs, which are replacing Hard Disk Drives (HDDs in consumer and enterprise scenarios. To keep the evolutionary pace of the technology, NAND Flash must scale aggressively in terms of bit cost. When approaching ultra-scaled technologies, planar NAND is hitting a wall: both academia researchers and industry worked to cope with this issue for several decades. Then, the 3D integration approach turned out to be the definitive alternative by eventually reaching mass production. This review paper exposes several 3D NAND Flash memory technologies, along with their related integration challenges, by showing their different layouts, scaling trends and performance/reliability features.

  6. Flash memory management system and method utilizing multiple block list windows

    Science.gov (United States)

    Chow, James (Inventor); Gender, Thomas K. (Inventor)

    2005-01-01

    The present invention provides a flash memory management system and method with increased performance. The flash memory management system provides the ability to efficiently manage and allocate flash memory use in a way that improves reliability and longevity, while maintaining good performance levels. The flash memory management system includes a free block mechanism, a disk maintenance mechanism, and a bad block detection mechanism. The free block mechanism provides efficient sorting of free blocks to facilitate selecting low use blocks for writing. The disk maintenance mechanism provides for the ability to efficiently clean flash memory blocks during processor idle times. The bad block detection mechanism provides the ability to better detect when a block of flash memory is likely to go bad. The flash status mechanism stores information in fast access memory that describes the content and status of the data in the flash disk. The new bank detection mechanism provides the ability to automatically detect when new banks of flash memory are added to the system. Together, these mechanisms provide a flash memory management system that can improve the operational efficiency of systems that utilize flash memory.

  7. uFLIP: Understanding the Energy Consumption of Flash Devices

    DEFF Research Database (Denmark)

    Bjørling, Matias; Bonnet, Philippe; Bouganim, Luc

    2010-01-01

    consumption (low power consumption in idle mode, average Watt consumption from the data sheets). Second, when measured at a sufficiently fine granularity, the energy consumption of a given device might complement the performance characteristics derived from its response time profile. Indeed, background work......Understanding the energy consumption of flash devices is important for two reasons. First, energy is emerging as a key metric for data management systems. It is thus important to understand how we can reason about the energy consumption of flash devices beyond their approximate aggregate...... which is not directly observable with a response time profile appears clearly when energy is used as a metric. In this paper, we discuss the results from the {uFLIP} benchmark applied to four different {SSD} devices using both response time and energy as metric....

  8. Discrete charge states in nanowire flash memory with multiple Ta2O5 charge-trapping stacks

    Science.gov (United States)

    Zhu, Hao; Bonevich, John E.; Li, Haitao; Richter, Curt A.; Yuan, Hui; Kirillov, Oleg; Li, Qiliang

    2014-06-01

    In this work, multi-bit flash-like memory cell based on Si nanowire field-effect transistor and multiple Ta2O5 charge-trapping stacks have been fabricated and fully characterized. The memory cells exhibited staircase, discrete charged states at small gate voltages. Such discrete multi-bit on one memory cell is attractive for high memory density. These non-volatile memory devices exhibited fast programming/erasing speed, excellent retention, and endurance, indicating the advantages of integrating the multilayer of charge-storage stacks on the nanowire channel. Such high-performance flash-like non-volatile memory can be integrated into the microprocessor chip as the local memory which requires high density and good endurance.

  9. Investigation of Supply Current Spikes in Flash Memories Using Ion-Electron Emission Microscopy

    Science.gov (United States)

    Gerardin, S.; Bagatin, M.; Paccagnella, A.; Bisello, D.; Giubilato, P.; Mattiazzo, S.; Pantano, D.; Silvestrin, L.; Tessaro, M.; Wyss, J.; Ferlet-Cavrois, V.

    2013-12-01

    We studied the occurrence of supply current spikes and destructive events in NAND flash memories under heavy-ion exposure. In addition to broad-beam experiments, we used collimated beams and ion-electron emission microscopy to investigate the phenomena on two types of memories with different feature size. Current spikes on the supply current were observed in both devices, also with collimated beams, whereas destructive events occurred only with broad beam. We show that current spikes do not originate from charge-pump capacitors, as previously suggested, and propose that destructive events are due to the effects of temporally close heavy-ion hits on distinct areas of the tested chips.

  10. Performance improvement of charge trap flash memory by using a composition-modulated high-k trapping layer

    International Nuclear Information System (INIS)

    Tang Zhen-Jie; Li Rong; Yin Jiang

    2013-01-01

    A composition-modulated (HfO 2 ) x (Al 2 O3) 1−x charge trapping layer is proposed for charge trap flash memory by controlling the Al atom content to form a peak and valley shaped band gap. It is found that the memory device using the composition-modulated (HfO 2 ) x (Al 2 O 3 ) 1−x as the charge trapping layer exhibits a larger memory window of 11.5 V, improves data retention even at high temperature, and enhances the program/erase speed. Improvements of the memory characteristics are attributed to the special band-gap structure resulting from the composition-modulated trapping layer. Therefore, the composition-modulated charge trapping layer may be useful in future nonvolatile flash memory device application. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  11. Non-volatile flash memory with discrete bionanodot floating gate assembled by protein template

    International Nuclear Information System (INIS)

    Miura, Atsushi; Yamashita, Ichiro; Uraoka, Yukiharu; Fuyuki, Takashi; Tsukamoto, Rikako; Yoshii, Shigeo

    2008-01-01

    We demonstrated non-volatile flash memory fabrication by utilizing uniformly sized cobalt oxide (Co 3 O 4 ) bionanodot (Co-BND) architecture assembled by a cage-shaped supramolecular protein template. A fabricated high-density Co-BND array was buried in a metal-oxide-semiconductor field-effect-transistor (MOSFET) structure to use as the charge storage node of a floating nanodot gate memory. We observed a clockwise hysteresis in the drain current-gate voltage characteristics of fabricated BND-embedded MOSFETs. Observed hysteresis obviously indicates a memory operation of Co-BND-embedded MOSFETs due to the charge confinement in the embedded BND and successful functioning of embedded BNDs as the charge storage nodes of the non-volatile flash memory. Fabricated Co-BND-embedded MOSFETs showed good memory properties such as wide memory windows, long charge retention and high tolerance to repeated write/erase operations. A new pathway for device fabrication by utilizing the versatile functionality of biomolecules is presented

  12. Non-volatile flash memory with discrete bionanodot floating gate assembled by protein template.

    Science.gov (United States)

    Miura, Atsushi; Tsukamoto, Rikako; Yoshii, Shigeo; Yamashita, Ichiro; Uraoka, Yukiharu; Fuyuki, Takashi

    2008-06-25

    We demonstrated non-volatile flash memory fabrication by utilizing uniformly sized cobalt oxide (Co(3)O(4)) bionanodot (Co-BND) architecture assembled by a cage-shaped supramolecular protein template. A fabricated high-density Co-BND array was buried in a metal-oxide-semiconductor field-effect-transistor (MOSFET) structure to use as the charge storage node of a floating nanodot gate memory. We observed a clockwise hysteresis in the drain current-gate voltage characteristics of fabricated BND-embedded MOSFETs. Observed hysteresis obviously indicates a memory operation of Co-BND-embedded MOSFETs due to the charge confinement in the embedded BND and successful functioning of embedded BNDs as the charge storage nodes of the non-volatile flash memory. Fabricated Co-BND-embedded MOSFETs showed good memory properties such as wide memory windows, long charge retention and high tolerance to repeated write/erase operations. A new pathway for device fabrication by utilizing the versatile functionality of biomolecules is presented.

  13. Ensuring the Trust of NAND Flash Memory: Going Beyond the Published Interface

    Science.gov (United States)

    2016-03-17

    Ensuring the Trust of NAND Flash Memory : Going Beyond the Published Interface Austin H. Roach, Matthew J. Gadlage, James D. Ingalls, Aaron...can be used to measure subtle changes in the memory cells of advanced Flash memories caused by program/erase stress, radiation exposure, or process...from COTS assemblies without publically available datasheets. Keywords: NAND Flash; partial program; partial erase; interrupted program; interrupted

  14. Fast neutron irradiation tests of flash memories used in space environment at the ISIS spallation neutron source

    Science.gov (United States)

    Andreani, C.; Senesi, R.; Paccagnella, A.; Bagatin, M.; Gerardin, S.; Cazzaniga, C.; Frost, C. D.; Picozza, P.; Gorini, G.; Mancini, R.; Sarno, M.

    2018-02-01

    This paper presents a neutron accelerated study of soft errors in advanced electronic devices used in space missions, i.e. Flash memories performed at the ChipIr and VESUVIO beam lines at the ISIS spallation neutron source. The two neutron beam lines are set up to mimic the space environment spectra and allow neutron irradiation tests on Flash memories in the neutron energy range above 10 MeV and up to 800 MeV. The ISIS neutron energy spectrum is similar to the one occurring in the atmospheric as well as in space and planetary environments, with intensity enhancements varying in the range 108- 10 9 and 106- 10 7 respectively. Such conditions are suitable for the characterization of the atmospheric, space and planetary neutron radiation environments, and are directly applicable for accelerated tests of electronic components as demonstrated here in benchmark measurements performed on flash memories.

  15. Fast neutron irradiation tests of flash memories used in space environment at the ISIS spallation neutron source

    Directory of Open Access Journals (Sweden)

    C. Andreani

    2018-02-01

    Full Text Available This paper presents a neutron accelerated study of soft errors in advanced electronic devices used in space missions, i.e. Flash memories performed at the ChipIr and VESUVIO beam lines at the ISIS spallation neutron source. The two neutron beam lines are set up to mimic the space environment spectra and allow neutron irradiation tests on Flash memories in the neutron energy range above 10 MeV and up to 800 MeV. The ISIS neutron energy spectrum is similar to the one occurring in the atmospheric as well as in space and planetary environments, with intensity enhancements varying in the range 108- 10 9 and 106- 10 7 respectively. Such conditions are suitable for the characterization of the atmospheric, space and planetary neutron radiation environments, and are directly applicable for accelerated tests of electronic components as demonstrated here in benchmark measurements performed on flash memories.

  16. Radiation Tests of Highly scaled, High-Density, Commercial, Nonvolatile NAND Flash Memories--Update 2011

    Science.gov (United States)

    Irom, Farokh; Nguyen, Duc N.

    2011-01-01

    High-density, commercial, nonvolatile flash memories with NAND architecture are now available from several manufacturers. This report examines SEE effects and TID response in single-level cell (SLC) 32Gb and multi-level cell (MLC) 64Gb NAND flash memories manufactured by Micron Technology.

  17. Radiation Tests of Highly Scaled, High-Density, Commercial, Nonvolatile NAND Flash Memories - Update 2010

    Science.gov (United States)

    Irom, Farokh; Nguyen, Duc N.

    2010-01-01

    High-density, commercial, nonvolatile flash memories with NAND architecture are now available from several manufacturers. This report examines SEE effects and TID response in single-level cell (SLC) and multi-level cell (MLC) NAND flash memories manufactured by Micron Technology.

  18. Heavy Ion Irradiation Fluence Dependence for Single-Event Upsets of NAND Flash Memory

    Science.gov (United States)

    Chen, Dakai; Wilcox, Edward; Ladbury, Raymond; Kim, Hak; Phan, Anthony; Seidleck, Christina; LaBel, Kenneth

    2016-01-01

    We investigated the single-event effect (SEE) susceptibility of the Micron 16 nm NAND flash, and found the single-event upset (SEU) cross section varied inversely with fluence. The SEU cross section decreased with increasing fluence. We attribute the effect to the variable upset sensitivities of the memory cells. The current test standards and procedures assume that SEU follow a Poisson process and do not take into account the variability in the error rate with fluence. Therefore, heavy ion irradiation of devices with variable upset sensitivity distribution using typical fluence levels may underestimate the cross section and on-orbit event rate.

  19. Investigation of impact of post-metallization annealing on reliability of 65 nm NOR floating-gate flash memories

    Science.gov (United States)

    Chiu, Shengfen; Xu, Yue; Ji, Xiaoli; Yan, Feng

    2016-12-01

    This paper investigates the impact of post-metallization annealing (PMA) in pure nitrogen ambient on the reliability of 65 nm NOR-type floating-gate flash memory devices. The experimental results show that, with PMA process, the cycling performance of flash cells, especially for the erasing speed is obviously degraded compared to that without PMA. It is found that the bulk oxide traps and tunnel oxide/Si interface traps are significantly increased with PMA treatment. The water/moisture residues left in the interlayer dielectric layers diffuse to tunnel oxide during PMA process is considered to be responsible for these traps generation, which further enhances the degradation of erase performance. Skipping PMA treatment is proposed to suppress the water diffusion effect on erase performance degradation of flash cells.

  20. Investigation of Current Spike Phenomena During Heavy Ion Irradiation of NAND Flash Memories

    Science.gov (United States)

    Oldham, Timothy R.; Berg, Melanie; Friendlich, Mark; Wilcox, Ted; Seidleck, Christina; LaBel, Kenneth A.; Irom, Farokh; Buchner, Steven P.; McMorrow, Dale; Mavis, David G.; hide

    2011-01-01

    A series of heavy ion and laser irradiations were performed to investigate previously reported current spikes in flash memories. High current events were observed, however, none matches the previously reported spikes. Plausible mechanisms are discussed.

  1. Heavy Ion Irradiation Fluence Dependence for Single-Event Upsets in a NAND Flash Memory

    Science.gov (United States)

    Chen, Dakai; Wilcox, Edward; Ladbury, Raymond L.; Kim, Hak; Phan, Anthony; Seidleck, Christina; Label, Kenneth

    2016-01-01

    We investigated the single-event effect (SEE) susceptibility of the Micron 16 nm NAND flash, and found that the single-event upset (SEU) cross section varied inversely with cumulative fluence. We attribute the effect to the variable upset sensitivities of the memory cells. Furthermore, the effect impacts only single cell upsets in general. The rate of multiple-bit upsets remained relatively constant with fluence. The current test standards and procedures assume that SEU follow a Poisson process and do not take into account the variability in the error rate with fluence. Therefore, traditional SEE testing techniques may underestimate the on-orbit event rate for a device with variable upset sensitivity.

  2. Reliability of modified tunneling barriers for high performance nonvolatile charge trap flash memory application

    Science.gov (United States)

    Park, Goon-Ho; Cho, Won-Ju

    2010-01-01

    Charge trap flash memory devices with modified tunneling barriers were fabricated using the tunneling barrier engineering technique. Variable oxide thickness (VARIOT) barrier and CRESTED barrier consisting of thin SiO2 and Si3N4 dielectric layers were used as engineered tunneling barriers. High-k dielectrics were used as charge trapping and blocking oxide layer to improve the program/erase speed. The VARIOT type tunneling barrier composed of oxide-nitride-oxide layers revealed reliable electrical characteristics; long retention time and superior endurance. On the other hand, the CRESTED tunneling barrier composed of nitride-oxide-nitride (NON) layers showed degraded retention and endurance characteristics. It is found that the degradation of NON barrier is associated with the increase in interface state density at tunneling barrier/silicon channel by programming and erasing (P/E) stress.

  3. Flash Memory Reliability: Read, Program, and Erase Latency Versus Endurance Cycling

    Science.gov (United States)

    Heidecker, Jason

    2010-01-01

    This report documents the efforts and results of the fiscal year (FY) 2010 NASA Electronic Parts and Packaging Program (NEPP) task for nonvolatile memory (NVM) reliability. This year's focus was to measure latency (read, program, and erase) of NAND Flash memories and determine how these parameters drift with erase/program/read endurance cycling.

  4. Optimal memory configuration analysis in tri-hybrid solid-state drives with storage class memory and multi-level cell/triple-level cell NAND flash memory

    Science.gov (United States)

    Matsui, Chihiro; Yamada, Tomoaki; Sugiyama, Yusuke; Yamaga, Yusuke; Takeuchi, Ken

    2017-04-01

    This paper analyzes the best mix of memories in a tri-hybrid solid-state drive (SSD) with storage class memory (SCM) and multi-level cell (MLC)/triple-level cell (TLC) NAND flash memory. SCM is fast but its cost is high. Although MLC NAND flash memory is slow, it is more cost effective than SCM. For further cost efficiency, TLC NAND flash memory is denser and less expensive than MLC NAND flash. Performance of tri-hybrid SSD is evaluated in various memory configurations. Moreover, the optimum memory configuration is changed according to the application characteristics. If 10% cost increase is allowed compared to the MLC NAND flash only SSD, SCM/MLC NAND flash hybrid SSD provides the best performance with hot/random workload, whereas SCM/MLC/TLC NAND flash tri-hybrid SSD achieves the best for hot/sequential and cold/random workloads. In addition, it is possible to add long latency but low-cost SCM to the tri-hybrid SSD. As a result, tri-hybrid SSD with slow SCM achieves the best performance.

  5. A fast and low-power microelectromechanical system-based non-volatile memory device.

    Science.gov (United States)

    Lee, Sang Wook; Park, Seung Joo; Campbell, Eleanor E B; Park, Yung Woo

    2011-01-01

    Several new generation memory devices have been developed to overcome the low performance of conventional silicon-based flash memory. In this study, we demonstrate a novel non-volatile memory design based on the electromechanical motion of a cantilever to provide fast charging and discharging of a floating-gate electrode. The operation is demonstrated by using an electromechanical metal cantilever to charge a floating gate that controls the charge transport through a carbon nanotube field-effect transistor. The set and reset currents are unchanged after more than 11 h constant operation. Over 500 repeated programming and erasing cycles were demonstrated under atmospheric conditions at room temperature without degradation. Multinary bit programming can be achieved by varying the voltage on the cantilever. The operation speed of the device is faster than a conventional flash memory and the power consumption is lower than other memory devices.

  6. Radiation Tests of Highly Scaled, High-Density, Commercial, Nonvolatile NAND Flash Memories - Update 2012

    Science.gov (United States)

    Irom, Farokh; Allen, Gregory R.

    2012-01-01

    The space radiation environment poses a certain risk to all electronic components on Earth-orbiting and planetary mission spacecraft. In recent years, there has been increased interest in the use of high-density, commercial, nonvolatile flash memories in space because of ever-increasing data volumes and strict power requirements. They are used in a wide variety of spacecraft subsystems. At one end of the spectrum, flash memories are used to store small amounts of mission-critical data such as boot code or configuration files and, at the other end, they are used to construct multi-gigabyte data recorders that record mission science data. This report examines single-event effect (SEE) and total ionizing dose (TID) response in single-level cell (SLC) 32-Gb, multi-level cell (MLC) 64-Gb, and Triple-level (TLC) 64-Gb NAND flash memories manufactured by Micron Technology with feature size of 25 nm.

  7. New memory devices based on the proton transfer process

    International Nuclear Information System (INIS)

    Wierzbowska, Małgorzata

    2016-01-01

    Memory devices operating due to the fast proton transfer (PT) process are proposed by the means of first-principles calculations. Writing  information is performed using the electrostatic potential of scanning tunneling microscopy (STM). Reading information is based on the effect of the local magnetization induced at the zigzag graphene nanoribbon (Z-GNR) edge—saturated with oxygen or the hydroxy group—and can be realized with the use of giant magnetoresistance (GMR), a magnetic tunnel junction or spin-transfer torque devices. The energetic barriers for the hop forward and backward processes can be tuned by the distance and potential of the STM tip; this thus enables us to tailor the non-volatile logic states. The proposed system enables very dense packing of the logic cells and could be used in random access and flash memory devices. (paper)

  8. New memory devices based on the proton transfer process

    Science.gov (United States)

    Wierzbowska, Małgorzata

    2016-01-01

    Memory devices operating due to the fast proton transfer (PT) process are proposed by the means of first-principles calculations. Writing information is performed using the electrostatic potential of scanning tunneling microscopy (STM). Reading information is based on the effect of the local magnetization induced at the zigzag graphene nanoribbon (Z-GNR) edge—saturated with oxygen or the hydroxy group—and can be realized with the use of giant magnetoresistance (GMR), a magnetic tunnel junction or spin-transfer torque devices. The energetic barriers for the hop forward and backward processes can be tuned by the distance and potential of the STM tip; this thus enables us to tailor the non-volatile logic states. The proposed system enables very dense packing of the logic cells and could be used in random access and flash memory devices.

  9. Silicon nano crystal-based non-volatile memory devices

    International Nuclear Information System (INIS)

    Ng, C.Y.; Chen, T.P.; Sreeduth, D.; Chen, Q.; Ding, L.; Du, A.

    2006-01-01

    In this work, we have investigated the performance and reliability of a Flash memory based on silicon nanocrystal synthesized with very-low energy ion beams. The devices are fabricated with a conventional CMOS process and the size of the nanocrystal is ∼ 4 nm as determined from TEM measurement. Electrical properties of the devices with a tunnel oxide of either 3 nm or 7 nm are evaluated. The devices exhibit good endurance up to 10 5 W/E cycles even at the high operation temperature of 85 deg. C for both the tunnel oxide thicknesses. For the thicker tunnel oxide (i.e., the 7-nm tunnel oxide), a good retention performance with an extrapolated 10-year memory window of ∼ 0.3 V (or ∼ 20% of charge lose after 10 years) is achieved. However, ∼ 70% of charge loss after 10 years is expected for the thinner tunnel oxide (i.e., the 3-nm tunnel oxide)

  10. Flash release - an alternative for releasing complex mems devices

    NARCIS (Netherlands)

    Deladi, S.; Svetovoy, Vitaly; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2004-01-01

    A novel time-saving and cost-effective release technique has been developed and is described. The physical nature of the process is explained in combination with experimental observations. The results of the flash release process are compared with those of freeze-drying and supercritical CO2

  11. Flash release an alternative for releasing complex MEMS devices

    NARCIS (Netherlands)

    Deladi, S.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2004-01-01

    A novel time-saving and cost-effective release technique has been developed and is described. The physical nature of the process is explained in combination with experimental observations. The results of the flash release process are compared with those of freeze-drying and supercritical CO2

  12. Tunable bandgap energy of fluorinated nanocrystals for flash memory applications produced by low-damage plasma treatment

    Science.gov (United States)

    Huang, Chi-Hsien; Lin, Chih-Ting; Wang, Jer-Chyi; Chou, Chien; Ye, Yu-Ren; Cheng, Bing-Ming; Lai, Chao-Sung

    2012-11-01

    A plasma system with a complementary filter to shield samples from damage during tetrafluoromethane (CF4) plasma treatment was proposed in order to incorporate fluorine atoms into gadolinium oxide nanocrystals (Gd2O3-NCs) for flash memory applications. X-ray photoelectron spectroscopy confirmed that fluorine atoms were successfully introduced into the Gd2O3-NCs despite the use of a filter in the plasma-enhanced chemical vapour deposition system to shield against several potentially damaging species. The number of incorporated fluorine atoms can be controlled by varying the treatment time. The optimized memory window of the resulting flash memory devices was twice that of devices treated by a filterless system because more fluorine atoms were incorporated into the Gd2O3-NCs film with very little damage. This enlarged the bandgap energy from 5.48 to 6.83 eV, as observed by ultraviolet absorption measurements. This bandgap expansion can provide a large built-in electric field that allows more charges to be stored in the Gd2O3-NCs. The maximum improvement in the retention characteristic was >60%. Because plasma damage during treatment is minimal, maximum fluorination can be achieved. The concept of simply adding a filter to a plasma system to prevent plasma damage exhibits great promise for functionalization or modification of nanomaterials for advanced nanoelectronics while introducing minimal defects.

  13. Organic nonvolatile memory devices based on ferroelectricity

    NARCIS (Netherlands)

    Naber, R.C.G.; Asadi, K.; Blom, P.W.M.; Leeuw, D.M. de; Boer, B. de

    2010-01-01

    A memory functionality is a prerequisite for many applications of electronic devices. Organic nonvolatile memory devices based on ferroelectricity are a promising approach toward the development of a low-cost memory technology. In this Review Article we discuss the latest developments in this area

  14. Simulation of trapping properties of high κ material as the charge storage layer for flash memory application

    International Nuclear Information System (INIS)

    Yeo, Yee Ngee; Wang Yingqian; Samanta, Santanu Kumar; Yoo, Won Jong; Samudra, Ganesh; Gao, Dongyue; Chong, Chee Ching

    2006-01-01

    We investigated the trapping properties of high κ material as the charge storage layer in non-volatile flash memory devices using a two-dimensional device simulator, Medici. The high κ material is sandwiched between two silicon oxide layers, resulting in the Silicon-Oxide-High κ-Oxide-Silicon (SOHOS) structure. The trap energy levels of the bulk electron traps in high κ material were determined. The programming and erasing voltage and time using Fowler Nordheim tunneling were estimated by simulation. The effect of deep level traps on erasing was investigated. Also, the effect of bulk traps density, thickness of block oxide and thickness of high κ material on the threshold voltage of the device was simulated

  15. Resistance Controllability in Alkynylgold(III) Complex-Based Resistive Memory for Flash-Type Storage Applications.

    Science.gov (United States)

    Wang, Peng; Fang, Yu; Jiang, Jun; Ji, Yujin; Li, Youyong; Zheng, Junwei; Xu, Qingfeng; Lu, Jianmei

    2017-07-18

    Owing to the demands of state-of-the-art information technologies that are suitable for vast data storage, the necessity for organic memory device (OMD) materials is highlighted. However, OMDs based on metal complexes are limited to several types of transition-metal complex systems containing nitrogen-donor ligands. Herein, attempts are made to introduce novel alkynylgold(III) materials into memory devices with superior performance. In this respect, an alkynyl-containing coumarin gold(III) complex, [(C 19 N 5 H 11 )Au-C≡C-C 9 H 5 O], has been synthesized and integrated into a sandwiched Al/[(C 19 N 5 H 11 )Au-C≡C-C 9 H 5 O]/indium tin oxide device. By precisely controlling the compliance current (I cc ), the devices show different switching characteristics from flash-type binary resistance switching (I cc ≤10 -3  A) to WORM-type (WORM=write once read many times) ternary resistance switching (I cc =10 -2  A). This work explores electrical gold(III) complex based memories for potential use in organic electronics. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. A concatenation scheme of LDPC codes and source codes for flash memories

    Science.gov (United States)

    Huang, Qin; Pan, Song; Zhang, Mu; Wang, Zulin

    2012-12-01

    Recently, low-density parity-check (LDPC) codes have been applied in flash memories to correct errors. However, as verified in this article, their performance degrades rapidly as the number of stuck cells increases. Thus, this paper presents a concatenation reliability scheme of LDPC codes and source codes, which aims to improve the performance of LDPC codes for flash memories with stuck cells. In this scheme, the locations of stuck cells is recorded by source codes in the write process such that erasures rather than wrong log-likelihood ratios on these cells are given in the read process. Then, LDPC codes correct these erasures and soft errors caused by cell-to-cell interferences. The analyses of channel capacity and compression rates of source codes with side information show that the memory cost of the proposed scheme is moderately low. Simulation results verify that the proposed scheme outperforms the traditional scheme with only LDPC codes.

  17. Space Qualified, Radiation Hardened, Dense Monolithic Flash Memory, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Radiation hardened nonvolatile memories for space is still primarily confined to EEPROM. There is high density effective or cost effective NVM solution available to...

  18. MoO3 trapping layers with CF4 plasma treatment in flash memory applications

    International Nuclear Information System (INIS)

    Kao, Chuyan Haur; Chen, Hsiang; Chen, Su-Zhien; Chen, Chian Yu; Lo, Kuang-Yu; Lin, Chun Han

    2014-01-01

    Highlights: • MoO 3 -based flash memories have been fabricated. • CF4 plasma treatment could enhance good memory performance. • Material analyses confirm that plasma treatment eliminated defects. • Fluorine atoms might fix the dangling bonds. - Abstract: In this research, we used MoO 3 with CF 4 plasma treatment as charge trapping layer in metal-oxide-high-k -oxide-Si-type memory. We analyzed material properties and electrical characteristics with multiple analyses. The plasma treatment could increase the trapping density, reduce the leakage current, expand band gap, and passivate the defect to enhance the memory performance. The MoO 3 charge trapping layer memory with suitable CF 4 plasma treatment is promising for future nonvolatile memory applications

  19. PLZT thermal/flash protective goggles: device concepts and constraints

    International Nuclear Information System (INIS)

    Cutchen, J.T.

    1979-01-01

    In 1975 Sandia Laboratories began the design and development of PLZT Goggles for the US Air Force to provide protection from temporary flashblindness and permanent retinal burns caused by the brilliant flash of nuclear explosions. The user requirements, system and physical constraints, and use/storage environments were all considered in arriving at the final design goals. When the program began, there was no industrial capability to manufacture large-aperture PLZT materials or bonded lens assemblies. The technology has been established from a laboratory baseline in a brief period, and operational testing and evaluation by the Air Force has been completed. The goggles, identified as the EEU-2/P,, are now in production

  20. 77 FR 35718 - Certain Universal Serial Bus (“USB”) Portable Storage Devices, Including USB Flash Drives and...

    Science.gov (United States)

    2012-06-14

    ... COMMISSION Certain Universal Serial Bus (``USB'') Portable Storage Devices, Including USB Flash Drives and... administrative law judge (``ALJ'') terminating the investigation as to all remaining respondents. FOR FURTHER... importation of certain universal serial bus (``USB'') portable storage devices, including USB flash drives and...

  1. Shape memory polymer medical device

    Science.gov (United States)

    Maitland, Duncan [Pleasant Hill, CA; Benett, William J [Livermore, CA; Bearinger, Jane P [Livermore, CA; Wilson, Thomas S [San Leandro, CA; Small, IV, Ward; Schumann, Daniel L [Concord, CA; Jensen, Wayne A [Livermore, CA; Ortega, Jason M [Pacifica, CA; Marion, III, John E.; Loge, Jeffrey M [Stockton, CA

    2010-06-29

    A system for removing matter from a conduit. The system includes the steps of passing a transport vehicle and a shape memory polymer material through the conduit, transmitting energy to the shape memory polymer material for moving the shape memory polymer material from a first shape to a second and different shape, and withdrawing the transport vehicle and the shape memory polymer material through the conduit carrying the matter.

  2. TID and SEE Response of an Advanced Samsung 4G NAND Flash Memory

    Science.gov (United States)

    Oldham, Timothy R.; Friendlich, M.; Howard, J. W.; Berg, M. D.; Kim, H. S.; Irwin, T. L.; LaBel, K. A.

    2007-01-01

    Initial total ionizing dose (TID) and single event heavy ion test results are presented for an unhardened commercial flash memory, fabricated with 63 nm technology. Results are that the parts survive to a TID of nearly 200 krad (SiO2), with a tractable soft error rate of about 10(exp -l2) errors/bit-day, for the Adams Ten Percent Worst Case Environment.

  3. Projected phase-change memory devices

    Science.gov (United States)

    Koelmans, Wabe W.; Sebastian, Abu; Jonnalagadda, Vara Prasad; Krebs, Daniel; Dellmann, Laurent; Eleftheriou, Evangelos

    2015-09-01

    Nanoscale memory devices, whose resistance depends on the history of the electric signals applied, could become critical building blocks in new computing paradigms, such as brain-inspired computing and memcomputing. However, there are key challenges to overcome, such as the high programming power required, noise and resistance drift. Here, to address these, we present the concept of a projected memory device, whose distinguishing feature is that the physical mechanism of resistance storage is decoupled from the information-retrieval process. We designed and fabricated projected memory devices based on the phase-change storage mechanism and convincingly demonstrate the concept through detailed experimentation, supported by extensive modelling and finite-element simulations. The projected memory devices exhibit remarkably low drift and excellent noise performance. We also demonstrate active control and customization of the programming characteristics of the device that reliably realize a multitude of resistance states.

  4. Technology breakthroughs in high performance metal-oxide-semiconductor devices for ultra-high density, low power non-volatile memory applications

    Science.gov (United States)

    Hong, Augustin Jinwoo

    Non-volatile memory devices have attracted much attention because data can be retained without power consumption more than a decade. Therefore, non-volatile memory devices are essential to mobile electronic applications. Among state of the art non-volatile memory devices, NAND flash memory has earned the highest attention because of its ultra-high scalability and therefore its ultra-high storage capacity. However, human desire as well as market competition requires not only larger storage capacity but also lower power consumption for longer battery life time. One way to meet this human desire and extend the benefits of NAND flash memory is finding out new materials for storage layer inside the flash memory, which is called floating gate in the state of the art flash memory device. In this dissertation, we study new materials for the floating gate that can lower down the power consumption and increase the storage capacity at the same time. To this end, we employ various materials such as metal nanodot, metal thin film and graphene incorporating complementary-metal-oxide-semiconductor (CMOS) compatible processes. Experimental results show excellent memory effects at relatively low operating voltages. Detailed physics and analysis on experimental results are discussed. These new materials for data storage can be promising candidates for future non-volatile memory application beyond the state of the art flash technologies.

  5. Analysis of the X-ray microbeam test result of the flash memories

    International Nuclear Information System (INIS)

    Yan Yihua; Ding Lili; Chen Wei; Guo Hongxia; Guo Xiaoqiang; Lin Dongsheng; Zhang Keying; Zhang Fengqi; Deng Yuliang; Fan Ruyu

    2013-01-01

    Background: The failure phenomenon is difficult to analyze for the flash memories when the whole chip is exposed to irradiation since both the memory array and the peripheral circuits might be degraded. Purpose: In order to detect the radiation susceptibility and corresponding phenomenon of the related circuits that included in the flash memories, the X-ray microbeam is used as the radiation source instead of 60 Co. Methods: The failure phenomenon is studied respectively when the memory array, decoder circuits, the charge pump circuits as well as the I/O circuits are exposed to radiation. The errors are mapped according to the logical address and the failure mechanism is analyzed based on the circuits. Results: Irradiated on the memory .array win lead to regularly distributed 0→1 bit flips, while only 1→0 are found when the row decoder is under exposure. Degradation of the charge pump circuits would lead to the erase/program functional failure. Conclusions: The results suggest that the X-ray microbeam radiation test is a good method for detecting the radiation susceptibility of the integrated circuits that contains lots of circuit modules. (authors)

  6. Analysis on applicable error-correcting code strength of storage class memory and NAND flash in hybrid storage

    Science.gov (United States)

    Matsui, Chihiro; Kinoshita, Reika; Takeuchi, Ken

    2018-04-01

    A hybrid of storage class memory (SCM) and NAND flash is a promising technology for high performance storage. Error correction is inevitable on SCM and NAND flash because their bit error rate (BER) increases with write/erase (W/E) cycles, data retention, and program/read disturb. In addition, scaling and multi-level cell technologies increase BER. However, error-correcting code (ECC) degrades storage performance because of extra memory reading and encoding/decoding time. Therefore, applicable ECC strength of SCM and NAND flash is evaluated independently by fixing ECC strength of one memory in the hybrid storage. As a result, weak BCH ECC with small correctable bit is recommended for the hybrid storage with large SCM capacity because SCM is accessed frequently. In contrast, strong and long-latency LDPC ECC can be applied to NAND flash in the hybrid storage with large SCM capacity because large-capacity SCM improves the storage performance.

  7. The Optimization of Gate All Around-L-Shaped Bottom Select Transistor in 3D NAND Flash Memory.

    Science.gov (United States)

    Zou, Xingqi; Jin, Lei; Jiang, Dandan; Zhang, Yu; Chen, Guoxing; Xia, Zhiliang; Huo, Zongliang

    2018-08-01

    In this work, the GAA (Gate All Around) L-Shaped bottom select transistor (BSG) in 3D NAND Flash Memory has been investigated. Different methods are proposed to optimize its performance from viewpoints of process and structure. BSG in 3D NAND is a novel device structure with two connected transistors: one is horizontal MOSFET (regarded as convention MOSFET) and one is vertical MOSFET (regarded as GAA transistor). With implant dose increasing in vertical channel, BSG Vth has much more tighter Vt distribution, which is beneficial for boosting potential improvement and program disturbance suppression. Meanwhile, BSG corner rounding is proposed to improve the characteristic of BSG. Experiment and TCAD simulation data are matches quite well, giving a way to improve cell characteristics distribution and self-boosting potential control in high density 3D NAND array.

  8. A mathematical model for metastable condition determination in highly flashing liquid flows through expansion devices

    International Nuclear Information System (INIS)

    Angelo, E.; Angelo, G.; Andrade, D.A.

    2012-01-01

    Highlights: ► A mathematical model to determine the metastable flow degree in expansions. ► This model is based on the evaporation wave theory and a pressure jump discontinuity condition. ► The proposed model is not appropriate in cases where is present a low intensity evaporation wave. - Abstract: The determination of the metastability condition in fluid flows through singularities (expansion devices) when flashing occurs is the key to determine the mass flow rate going through devices when there is a great pressure difference between upstream and downstream. An application of the evaporation waves considered together with a maximizing condition for the pressure jump through the wave to determine the metastable state is presented. The model results are compared to several outflows reported in the literature indicating values within engineering standards for those flows in which fluids are highly superheated (highly expanded flashing liquid jets).

  9. A low-voltage flash memory cell utilizing the gate-injection program/erase method with a recessed channel structure

    International Nuclear Information System (INIS)

    Wu Dake; Huang Ru; Wang Pengfei; Tang Poren; Wang Yangyuan

    2008-01-01

    In this paper, a low-voltage recessed channel SONOS flash memory using the gate-injection program/erase method is proposed and investigated for NAND application. It is shown that the proposed flash memory can achieve 8 V lower programming voltage compared with planar flash memory, due to the effective capacitance coupling and the electric-field enhancement by combining the recessed channel structure and the gate-injection program/erase method. In addition, more than 30% larger threshold voltage window and improved short channel effects can be obtained in the proposed flash memory

  10. High performance SONOS flash memory with in-situ silicon nanocrystals embedded in silicon nitride charge trapping layer

    Science.gov (United States)

    Lim, Jae-Gab; Yang, Seung-Dong; Yun, Ho-Jin; Jung, Jun-Kyo; Park, Jung-Hyun; Lim, Chan; Cho, Gyu-seok; Park, Seong-gye; Huh, Chul; Lee, Hi-Deok; Lee, Ga-Won

    2018-02-01

    In this paper, SONOS-type flash memory device with highly improved charge-trapping efficiency is suggested by using silicon nanocrystals (Si-NCs) embedded in silicon nitride (SiNX) charge trapping layer. The Si-NCs were in-situ grown by PECVD without additional post annealing process. The fabricated device shows high program/erase speed and retention property which is suitable for multi-level cell (MLC) application. Excellent performance and reliability for MLC are demonstrated with large memory window of ∼8.5 V and superior retention characteristics of 7% charge loss for 10 years. High resolution transmission electron microscopy image confirms the Si-NC formation and the size is around 1-2 nm which can be verified again in X-ray photoelectron spectroscopy (XPS) where pure Si bonds increase. Besides, XPS analysis implies that more nitrogen atoms make stable bonds at the regular lattice point. Photoluminescence spectra results also illustrate that Si-NCs formation in SiNx is an effective method to form deep trap states.

  11. A light writable microfluidic "flash memory": optically addressed actuator array with latched operation for microfluidic applications.

    Science.gov (United States)

    Hua, Zhishan; Pal, Rohit; Srivannavit, Onnop; Burns, Mark A; Gulari, Erdogan

    2008-03-01

    This paper presents a novel optically addressed microactuator array (microfluidic "flash memory") with latched operation. Analogous to the address-data bus mediated memory address protocol in electronics, the microactuator array consists of individual phase-change based actuators addressed by localized heating through focused light patterns (address bus), which can be provided by a modified projector or high power laser pointer. A common pressure manifold (data bus) for the entire array is used to generate large deflections of the phase change actuators in the molten phase. The use of phase change material as the working media enables latched operation of the actuator array. After the initial light "writing" during which the phase is temporarily changed to molten, the actuated status is self-maintained by the solid phase of the actuator without power and pressure inputs. The microfluidic flash memory can be re-configured by a new light illumination pattern and common pressure signal. The proposed approach can achieve actuation of arbitrary units in a large-scale array without the need for complex external equipment such as solenoid valves and electrical modules, which leads to significantly simplified system implementation and compact system size. The proposed work therefore provides a flexible, energy-efficient, and low cost multiplexing solution for microfluidic applications based on physical displacements. As an example, the use of the latched microactuator array as "normally closed" or "normally open" microvalves is demonstrated. The phase-change wax is fully encapsulated and thus immune from contamination issues in fluidic environments.

  12. Operational method of a ferroelectric (Fe)-NAND flash memory array

    International Nuclear Information System (INIS)

    Wang, Shouyu; Takahashi, Mitue; Li, Qiu-Hong; Sakai, Shigeki; Takeuchi, Ken

    2009-01-01

    Operations of arrayed ferroelectric (Fe)-NAND flash memory cells: erase, program and read were demonstrated for the first time using a small cell array of four word lines by two NAND strings. The memory cells and select-gate transistors were all n-channel Pt/SrBi 2 Ta 2 O 9 /Hf-Al-O/Si ferroelectric-gate field effect transistors. The erase was performed by applying 10 µs wide 7 V pulses to n- and p-wells. The program was performed by applying 10 µs wide 7 V pulses to selected word lines. Accumulated read currents of 51 programmed patterns in the Fe-NAND flash memory cell array successfully showed distribution of the two distinguishable '0' and '1' states. The margin between the two states became wider by applying a verification technique in programming a cell out of the eight. Retention times of bit-line currents were obtained over 33 h for both the '0' and '1' states in a program pattern

  13. Comparative Analysis of Bandgap-Engineered Pillar Type Flash Memory with HfO2 and S3N4 as Trapping Layer

    Science.gov (United States)

    Lee, Sang-Youl; Yang, Seung-Dong; Oh, Jae-Sub; Yun, Ho-Jin; Jeong, Kwang-Seok; Kim, Yu-Mi; Lee, Hi-Deok; Lee, Ga-Won

    In this paper, we fabricated a gate-all-around bandgap- engineered (BE) silicon-oxide-nitride-oxide-silicon (SONOS) and silicon-oxide-high-k-oxide-silicon (SOHOS) flash memory device with a vertical silicon pillar type structure for a potential solution to scaling down. Silicon nitride (Si3N4) and hafnium oxide (HfO2) were used as trapping layers in the SONOS and SOHOS devices, respectively. The BE-SOHOS device has better electrical characteristics such as a lower threshold voltage (VTH) of 0.16V, a higher gm.max of 0.593µA/V and on/off current ratio of 5.76×108, than the BE-SONOS device. The memory characteristics of the BE-SONOS device, such as program/erase speed (P/E speed), endurance, and data retention, were compared with those of the BE-SOHOS device. The measured data show that the BE-SONOS device has good memory characteristics, such as program speed and data retention. Compared with the BE-SONOS device, the erase speed is enhanced about five times in BE-SOHOS, while the program speed and data retention characteristic are slightly worse, which can be explained via the many interface traps between the trapping layer and the tunneling oxide.

  14. A low-voltage sense amplifier with two-stage operational amplifier clamping for flash memory

    Science.gov (United States)

    Guo, Jiarong

    2017-04-01

    A low-voltage sense amplifier with reference current generator utilizing two-stage operational amplifier clamp structure for flash memory is presented in this paper, capable of operating with minimum supply voltage at 1 V. A new reference current generation circuit composed of a reference cell and a two-stage operational amplifier clamping the drain pole of the reference cell is used to generate the reference current, which avoids the threshold limitation caused by current mirror transistor in the traditional sense amplifier. A novel reference voltage generation circuit using dummy bit-line structure without pull-down current is also adopted, which not only improves the sense window enhancing read precision but also saves power consumption. The sense amplifier was implemented in a flash realized in 90 nm flash technology. Experimental results show the access time is 14.7 ns with power supply of 1.2 V and slow corner at 125 °C. Project supported by the National Natural Science Fundation of China (No. 61376028).

  15. Non-volatile memory devices with redox-active diruthenium molecular compound

    International Nuclear Information System (INIS)

    Pookpanratana, S; Zhu, H; Bittle, E G; Richter, C A; Li, Q; Hacker, C A; Natoli, S N; Ren, T

    2016-01-01

    Reduction-oxidation (redox) active molecules hold potential for memory devices due to their many unique properties. We report the use of a novel diruthenium-based redox molecule incorporated into a non-volatile Flash-based memory device architecture. The memory capacitor device structure consists of a Pd/Al 2 O 3 /molecule/SiO 2 /Si structure. The bulky ruthenium redox molecule is attached to the surface by using a ‘click’ reaction and the monolayer structure is characterized by x-ray photoelectron spectroscopy to verify the Ru attachment and molecular density. The ‘click’ reaction is particularly advantageous for memory applications because of (1) ease of chemical design and synthesis, and (2) provides an additional spatial barrier between the oxide/silicon to the diruthenium molecule. Ultraviolet photoelectron spectroscopy data identified the energy of the electronic levels of the surface before and after surface modification. The molecular memory devices display an unsaturated charge storage window attributed to the intrinsic properties of the redox-active molecule. Our findings demonstrate the strengths and challenges with integrating molecular layers within solid-state devices, which will influence the future design of molecular memory devices. (paper)

  16. Non-volatile memory devices with redox-active diruthenium molecular compound.

    Science.gov (United States)

    Pookpanratana, S; Zhu, H; Bittle, E G; Natoli, S N; Ren, T; Richter, C A; Li, Q; Hacker, C A

    2016-03-09

    Reduction-oxidation (redox) active molecules hold potential for memory devices due to their many unique properties. We report the use of a novel diruthenium-based redox molecule incorporated into a non-volatile Flash-based memory device architecture. The memory capacitor device structure consists of a Pd/Al2O3/molecule/SiO2/Si structure. The bulky ruthenium redox molecule is attached to the surface by using a 'click' reaction and the monolayer structure is characterized by x-ray photoelectron spectroscopy to verify the Ru attachment and molecular density. The 'click' reaction is particularly advantageous for memory applications because of (1) ease of chemical design and synthesis, and (2) provides an additional spatial barrier between the oxide/silicon to the diruthenium molecule. Ultraviolet photoelectron spectroscopy data identified the energy of the electronic levels of the surface before and after surface modification. The molecular memory devices display an unsaturated charge storage window attributed to the intrinsic properties of the redox-active molecule. Our findings demonstrate the strengths and challenges with integrating molecular layers within solid-state devices, which will influence the future design of molecular memory devices.

  17. Asymmetric Programming: A Highly Reliable Metadata Allocation Strategy for MLC NAND Flash Memory-Based Sensor Systems

    Directory of Open Access Journals (Sweden)

    Min Huang

    2014-10-01

    Full Text Available While the NAND flash memory is widely used as the storage medium in modern sensor systems, the aggressive shrinking of process geometry and an increase in the number of bits stored in each memory cell will inevitably degrade the reliability of NAND flash memory. In particular, it’s critical to enhance metadata reliability, which occupies only a small portion of the storage space, but maintains the critical information of the file system and the address translations of the storage system. Metadata damage will cause the system to crash or a large amount of data to be lost. This paper presents Asymmetric Programming, a highly reliable metadata allocation strategy for MLC NAND flash memory storage systems. Our technique exploits for the first time the property of the multi-page architecture of MLC NAND flash memory to improve the reliability of metadata. The basic idea is to keep metadata in most significant bit (MSB pages which are more reliable than least significant bit (LSB pages. Thus, we can achieve relatively low bit error rates for metadata. Based on this idea, we propose two strategies to optimize address mapping and garbage collection. We have implemented Asymmetric Programming on a real hardware platform. The experimental results show that Asymmetric Programming can achieve a reduction in the number of page errors of up to 99.05% with the baseline error correction scheme.

  18. Asymmetric programming: a highly reliable metadata allocation strategy for MLC NAND flash memory-based sensor systems.

    Science.gov (United States)

    Huang, Min; Liu, Zhaoqing; Qiao, Liyan

    2014-10-10

    While the NAND flash memory is widely used as the storage medium in modern sensor systems, the aggressive shrinking of process geometry and an increase in the number of bits stored in each memory cell will inevitably degrade the reliability of NAND flash memory. In particular, it's critical to enhance metadata reliability, which occupies only a small portion of the storage space, but maintains the critical information of the file system and the address translations of the storage system. Metadata damage will cause the system to crash or a large amount of data to be lost. This paper presents Asymmetric Programming, a highly reliable metadata allocation strategy for MLC NAND flash memory storage systems. Our technique exploits for the first time the property of the multi-page architecture of MLC NAND flash memory to improve the reliability of metadata. The basic idea is to keep metadata in most significant bit (MSB) pages which are more reliable than least significant bit (LSB) pages. Thus, we can achieve relatively low bit error rates for metadata. Based on this idea, we propose two strategies to optimize address mapping and garbage collection. We have implemented Asymmetric Programming on a real hardware platform. The experimental results show that Asymmetric Programming can achieve a reduction in the number of page errors of up to 99.05% with the baseline error correction scheme.

  19. Asymmetric Programming: A Highly Reliable Metadata Allocation Strategy for MLC NAND Flash Memory-Based Sensor Systems

    Science.gov (United States)

    Huang, Min; Liu, Zhaoqing; Qiao, Liyan

    2014-01-01

    While the NAND flash memory is widely used as the storage medium in modern sensor systems, the aggressive shrinking of process geometry and an increase in the number of bits stored in each memory cell will inevitably degrade the reliability of NAND flash memory. In particular, it's critical to enhance metadata reliability, which occupies only a small portion of the storage space, but maintains the critical information of the file system and the address translations of the storage system. Metadata damage will cause the system to crash or a large amount of data to be lost. This paper presents Asymmetric Programming, a highly reliable metadata allocation strategy for MLC NAND flash memory storage systems. Our technique exploits for the first time the property of the multi-page architecture of MLC NAND flash memory to improve the reliability of metadata. The basic idea is to keep metadata in most significant bit (MSB) pages which are more reliable than least significant bit (LSB) pages. Thus, we can achieve relatively low bit error rates for metadata. Based on this idea, we propose two strategies to optimize address mapping and garbage collection. We have implemented Asymmetric Programming on a real hardware platform. The experimental results show that Asymmetric Programming can achieve a reduction in the number of page errors of up to 99.05% with the baseline error correction scheme. PMID:25310473

  20. Flash μ-fluidics: a rapid prototyping method for fabricating microfluidic devices

    KAUST Repository

    Buttner, Ulrich

    2016-08-01

    Microfluidics has advanced in terms of design and structures; however, fabrication methods are time-consuming or expensive relative to facility costs and equipment needed. This work demonstrates a fast and economically viable 2D/3D maskless digital light-projection method based on a stereolithography process. Unlike other fabrication methods, one exposure step is used to form the whole device. Flash microfluidics is achieved by incorporating bonding and channel fabrication of complex structures in just 2.5 s to 4 s and by fabricating channel heights between 25 μm and 150 μm with photopolymer resin. The features of this fabrication technique, such as time and cost saving and easy fabrication, are used to build devices that are mostly needed in microfluidic/lab-on-chip systems. Due to the fast production method and low initial setup costs, the process could be used for point of care applications. © 2016 The Royal Society of Chemistry.

  1. Temperature self-adaptive program algorithm on 65 nm MLC NOR flash memory

    International Nuclear Information System (INIS)

    Shi Weihua; Hong Zhiliang; Hu Chaohong; Kang Yong

    2009-01-01

    This paper presents an implementation for improving muti-level cell NOR flash memory program throughput based on the channel hot electron (CHE) temperature characteristic. The CHE I g temperature characteristic is analyzed theoretically with the Lucky electron model, and a temperature self-adaptive programming algorithm is proposed to increase I g according to the on-die temperature. Experimental results show that the program throughput increases significantly from 1.1 MByte/s without temperature self-adaptive programming to 1.4 MByte/s with the proposed method at room temperature. This represents a 30% improvement and is 70 times faster than the program throughput in Ref. [1]. (semiconductor integrated circuits)

  2. An Analysis of MARSIS Radar Flash Memory Data from Lunae Planum, Mars: Searching for Subsurface Structures.

    Science.gov (United States)

    Caprarelli, G.; Orosei, R.; Mastrogiuseppe, M.; Cartacci, M.

    2017-12-01

    Lunae Planum is a Martian plain measuring approximately 1000 km in width and 2000 km in length, centered at coordinates 294°E-11°N. MOLA elevations range from +2500 m to +500 m in the south, gently sloping northward to -500 m. The plain is part of a belt of terrains located between the southern highlands and the northern lowlands, that are transitional in character (e.g., by elevation, age and morphology). These transitional terrains are poorly understood, in part because of their relative lack of major geomorphological features. They record however a very significant part of Mars's geologic history. The most evident features on Lunae Planum's Hesperian surface are regularly spaced, longitudinally striking, wrinkle ridges. These indicate the presence of blind thrust faults cutting through thick stacks of layers of volcanic or sedimentary rocks. The presence of fluidized ejecta craters scattered all over the region suggests also the presence of ice or volatiles in the subsurface. In a preliminary study of Lunae Planum's subsurface we used the Mars Express ground penetrating radar MARSIS dataset [1], in order to detect reflectors that could indicate the presence of fault planes or layering. Standard radargrams however, provided no evidence of changes in value of dielectric constant that could indicate possible geologic discontinuities or stratification of physically diverse materials. We thus started a new investigation based on processing of raw MARSIS data. Here we report on the preliminary results of this study. We searched the MARSIS archive for raw data stored in flash memory. When operating with flash storage, the radar collects 2 frequency bands along-track covering a distance = 100-250 km, depending on the orbiter altitude [2]. We found flash memory data from 24 orbits over the area. We processed the data focusing radar returns in off-nadir directions, to maximize the likelihood of detecting sloping subsurface structures, including those striking parallel

  3. Robust resistive memory devices using solution-processable metal-coordinated azo aromatics

    Science.gov (United States)

    Goswami, Sreetosh; Matula, Adam J.; Rath, Santi P.; Hedström, Svante; Saha, Surajit; Annamalai, Meenakshi; Sengupta, Debabrata; Patra, Abhijeet; Ghosh, Siddhartha; Jani, Hariom; Sarkar, Soumya; Motapothula, Mallikarjuna Rao; Nijhuis, Christian A.; Martin, Jens; Goswami, Sreebrata; Batista, Victor S.; Venkatesan, T.

    2017-12-01

    Non-volatile memories will play a decisive role in the next generation of digital technology. Flash memories are currently the key player in the field, yet they fail to meet the commercial demands of scalability and endurance. Resistive memory devices, and in particular memories based on low-cost, solution-processable and chemically tunable organic materials, are promising alternatives explored by the industry. However, to date, they have been lacking the performance and mechanistic understanding required for commercial translation. Here we report a resistive memory device based on a spin-coated active layer of a transition-metal complex, which shows high reproducibility (~350 devices), fast switching (106 s) and scalability (down to ~60 nm2). In situ Raman and ultraviolet-visible spectroscopy alongside spectroelectrochemistry and quantum chemical calculations demonstrate that the redox state of the ligands determines the switching states of the device whereas the counterions control the hysteresis. This insight may accelerate the technological deployment of organic resistive memories.

  4. Effect of redox proteins on the behavior of non-volatile memory.

    Science.gov (United States)

    Lee, Ji Hyun; Yew, Seung Chul; Cho, Jinhan; Kim, Youn Sang

    2012-12-21

    We demonstrated the memory effect of redox proteins in organic field-effect transistor (OFET) flash memory devices. Redox proteins include a heme structure, which has reversible redox reactions. These properties of the proteins could be successfully applied to the flash memory devices, which show a considerable memory window (~11 V) and relatively good endurance properties (~over 100 cycles).

  5. Total Ionizing Dose Influence on the Single Event Effect Sensitivity in Samsung 8Gb NAND Flash Memories

    Science.gov (United States)

    Edmonds, Larry D.; Irom, Farokh; Allen, Gregory R.

    2017-08-01

    A recent model provides risk estimates for the deprogramming of initially programmed floating gates via prompt charge loss produced by an ionizing radiation environment. The environment can be a mixture of electrons, protons, and heavy ions. The model requires several input parameters. This paper extends the model to include TID effects in the control circuitry by including one additional parameter. Parameters intended to produce conservative risk estimates for the Samsung 8 Gb SLC NAND flash memory are given, subject to some qualifications.

  6. Memory and Spin Injection Devices Involving Half Metals

    Directory of Open Access Journals (Sweden)

    M. Shaughnessy

    2011-01-01

    Full Text Available We suggest memory and spin injection devices fabricated with half-metallic materials and based on the anomalous Hall effect. Schematic diagrams of the memory chips, in thin film and bulk crystal form, are presented. Spin injection devices made in thin film form are also suggested. These devices do not need any external magnetic field but make use of their own magnetization. Only a gate voltage is needed. The carriers are 100% spin polarized. Memory devices may potentially be smaller, faster, and less volatile than existing ones, and the injection devices may be much smaller and more efficient than existing spin injection devices.

  7. Channel shape and interpoly dielectric material effects on electrical characteristics of floating-gate-type three-dimensional fin channel flash memories

    Science.gov (United States)

    Liu, Yongxun; Nabatame, Toshihide; Nguyen, Num; Matsukawa, Takashi; Endo, Kazuhiko; O'uchi, Shinichi; Tsukada, Junichi; Yamauchi, Hiromi; Ishikawa, Yuki; Mizubayashi, Wataru; Morita, Yukinori; Migita, Shinji; Ota, Hiroyuki; Chikyow, Toyohiro; Masahara, Meishoku

    2015-04-01

    Floating-gate (FG)-type three-dimensional (3D) fin channel flash memories with triangular fin (TF) and rectangular fin (RF) channels and different interpoly dielectric (IPD) materials have been successfully fabricated using (100)- and (110)-oriented silicon-on-insulator (SOI) wafers and orientation-dependent wet etching. The electrical characteristics of the fabricated FG-type 3D fin channel flash memories including threshold voltage (Vt) variability, program/erase (P/E) speed, memory window, endurance, and data retention at room temperature and 85 °C have been comparatively investigated. A higher P/E speed, a larger memory window, and a lower-voltage operation are experimentally obtained in the TF channel flash memories with an Al2O3-nitride-oxide (ANO) IPD layer (TF-ANO) than in the RF channel ones with the same ANO IPD layer (RF-ANO) and the TF channel ones with an oxide-nitride-oxide (ONO) IPD layer (TF-ONO). The larger memory window and lower-voltage operation of TF-ANO flash memories are due to the high-k effect of the Al2O3 layer and the electric field enhancement at the sharp foot edges of the TF channels. It was also found that data retention for all fabricated FG-type 3D fin channel flash memories shows a weak dependence on temperature.

  8. Flash-Aware Page Replacement Algorithm

    Directory of Open Access Journals (Sweden)

    Guangxia Xu

    2014-01-01

    Full Text Available Due to the limited main memory resource of consumer electronics equipped with NAND flash memory as storage device, an efficient page replacement algorithm called FAPRA is proposed for NAND flash memory in the light of its inherent characteristics. FAPRA introduces an efficient victim page selection scheme taking into account the benefit-to-cost ratio for evicting each victim page candidate and the combined recency and frequency value, as well as the erase count of the block to which each page belongs. Since the dirty victim page often contains clean data that exist in both the main memory and the NAND flash memory based storage device, FAPRA only writes the dirty data within the victim page back to the NAND flash memory based storage device in order to reduce the redundant write operations. We conduct a series of trace-driven simulations and experimental results show that our proposed FAPRA algorithm outperforms the state-of-the-art algorithms in terms of page hit ratio, the number of write operations, runtime, and the degree of wear leveling.

  9. A study on electromechanical carbon nanotube memory devices

    International Nuclear Information System (INIS)

    Kang, Jeong Won; Hwang, Ho Jung

    2005-01-01

    Electromechanical operations of carbon-nanotube (CNT) bridge memory device were investigated by using atomistic simulations based on empirical potentials. The nanotube-bridge memory device was operated by the electrostatic and the van der Waals forces acting on the nanotube-bridge. For the CNT bridge memory device, the van der Waals interactions between the CNT bridge and the oxide were very important. As the distance between the CNT bridge and the oxide decreased and the van der Waals interaction energy increased, the pull-in bias of the CNT-bridge decreased and the nonvolatility of the nanotube-bridge memory device increased, while the pull-out voltages increased. When the materials composed of the oxide film are different, since the van der Waals interactions must be also different, the oxide materials must be carefully selected for the CNT-bridge memory device to work as a nonvolatile memory.

  10. Anomalous Threshold Voltage Variability of Nitride Based Charge Storage Nonvolatile Memory Devices

    Directory of Open Access Journals (Sweden)

    Meng Chuan Lee

    2013-01-01

    Full Text Available Conventional technology scaling is implemented to meet the insatiable demand of high memory density and low cost per bit of charge storage nonvolatile memory (NVM devices. In this study, effect of technology scaling to anomalous threshold voltage ( variability is investigated thoroughly on postcycled and baked nitride based charge storage NVM devices. After long annealing bake of high temperature, cell’s variability of each subsequent bake increases within stable distribution and found exacerbate by technology scaling. Apparent activation energy of this anomalous variability was derived through Arrhenius plots. Apparent activation energy (Eaa of this anomalous variability is 0.67 eV at sub-40 nm devices which is a reduction of approximately 2 times from 110 nm devices. Technology scaling clearly aggravates this anomalous variability, and this poses reliability challenges to applications that demand strict control, for example, reference cells that govern fundamental program, erase, and verify operations of NVM devices. Based on critical evidence, this anomalous variability is attributed to lateral displacement of trapped charges in nitride storage layer. Reliability implications of this study are elucidated. Moreover, potential mitigation methods are proposed to complement technology scaling to prolong the front-runner role of nitride based charge storage NVM in semiconductor flash memory market.

  11. Microwave impedance imaging on semiconductor memory devices

    Science.gov (United States)

    Kundhikanjana, Worasom; Lai, Keji; Yang, Yongliang; Kelly, Michael; Shen, Zhi-Xun

    2011-03-01

    Microwave impedance microscopy (MIM) maps out the real and imaginary components of the tip-sample impedance, from which the local conductivity and dielectric constant distribution can be derived. The stray field contribution is minimized in our shielded cantilever design, enabling quantitative analysis of nano-materials and device structures. We demonstrate here that the MIM can spatially resolve the conductivity variation in a dynamic random access memory (DRAM) sample. With DC or low-frequency AC bias applied to the tip, contrast between n-doped and p-doped regions in the dC/dV images is observed, and p-n junctions are highlighted in the dR/dV images. The results can be directly compared with data taken by scanning capacitance microscope (SCM), which uses unshielded cantilevers and resonant electronics, and the MIM reveals more information of the local dopant concentration than SCM.

  12. Non-volatile memory devices based on polystyrene derivatives with electron-donating oligofluorene pendent moieties.

    Science.gov (United States)

    Liu, Cheng-Liang; Hsu, Jung-Ching; Chen, Wen-Chang; Sugiyama, Kenji; Hirao, Akira

    2009-09-01

    We report bistable non-volatile memory devices based on polystyrene derivatives containing pendent electron-donating mono-, di-, and tri(9,9-dihexylfluorene), which are denoted as poly(St-Fl), poly(St-Fl(2)), and poly(St-Fl(3)), respectively. The effects of the oligofluorene chain lengths and polymer surface structures on the memory characteristics were explored. Poly(St-Fl)-, poly(St-Fl(2))-, and poly(St-Fl(3))-based devices exhibited a flash memory characteristic with different turn-on threshold voltages of 2.8, 2.0, and 1.8 V, respectively, which was on the reverse trend with the highest occupied molecular orbital levels of -5.86, -5.80, and -5.77 eV. Moreover, the memory device showed a high ON/OFF current ratio of 2.5 x 10(4) and a long retention time of 10(4) s. The possible mechanism of the switching behavior was explained by the space-charge-limited-current theory and filamentary conduction. The larger aggregation domain size of the polymer thin film processed from the mixed solvent of chlorobenzene/N,N-dimethylformamide probably promoted the diffusion of the Al atoms into the polymer film and formed the conduction channel. Thus, it significantly reduced the turn-on threshold voltage on the studied polymer memory devices. The present study suggested that the polymer memory characteristics could be efficiently tuned through the pendent conjugated chain length and surface structures.

  13. Program scheme using common source lines in channel stacked NAND flash memory with layer selection by multilevel operation

    Science.gov (United States)

    Kim, Do-Bin; Kwon, Dae Woong; Kim, Seunghyun; Lee, Sang-Ho; Park, Byung-Gook

    2018-02-01

    To obtain high channel boosting potential and reduce a program disturbance in channel stacked NAND flash memory with layer selection by multilevel (LSM) operation, a new program scheme using boosted common source line (CSL) is proposed. The proposed scheme can be achieved by applying proper bias to each layer through its own CSL. Technology computer-aided design (TCAD) simulations are performed to verify the validity of the new method in LSM. Through TCAD simulation, it is revealed that the program disturbance characteristics is effectively improved by the proposed scheme.

  14. Radiation Damage in Electronic Memory Devices

    OpenAIRE

    Fetahović, Irfan; Pejović, Milić; Vujisić, Miloš

    2013-01-01

    This paper investigates the behavior of semiconductor memories exposed to radiation in order to establish their applicability in a radiation environment. The experimental procedure has been used to test radiation hardness of commercial semiconductor memories. Different types of memory chips have been exposed to indirect ionizing radiation by changing radiation dose intensity. The effect of direct ionizing radiation on semiconductor memory behavior has been analyzed by using Monte Carlo simula...

  15. Transistor and memory devices based on novel organic and biomaterials

    Science.gov (United States)

    Tseng, Jia-Hung

    Organic semiconductor devices have aroused considerable interest because of the enormous potential in many technological applications. Organic electroluminescent devices have been extensively applied in display technology. Rapid progress has also been made in transistor and memory devices. This thesis considers aspects of the transistor based on novel organic single crystals and memory devices using hybrid nanocomposites comprising polymeric/inorganic nanoparticles, and biomolecule/quantum dots. Organic single crystals represent highly ordered structures with much less imperfections compared to amorphous thin films for probing the intrinsic charge transport in transistor devices. We demonstrate that free-standing, thin organic single crystals with natural flexing ability can be fabricated as flexible transistors. We study the surface properties of the organic crystals to determine a nearly perfect surface leading to high performance transistors. The flexible transistors can maintain high performance under reversible bending conditions. Because of the high quality crystal technique, we further develop applications on organic complementary circuits and organic single crystal photovoltaics. In the second part, two aspects of memory devices are studied. We examine the charge transfer process between conjugated polymers and metal nanoparticles. This charge transfer process is essential for the conductance switching in nanoseconds to induce the memory effect. Under the reduction condition, the charge transfer process is eliminated as well as the memory effect, raising the importance of coupling between conjugated systems and nanoparticle accepters. The other aspect of memory devices focuses on the interaction of virus biomolecules with quantum dots or metal nanoparticles in the devices. We investigate the impact of memory function on the hybrid bio-inorganic system. We perform an experimental analysis of the charge storage activation energy in tobacco mosaic virus with

  16. Memory-assisted measurement-device-independent quantum key distribution

    Science.gov (United States)

    Panayi, Christiana; Razavi, Mohsen; Ma, Xiongfeng; Lütkenhaus, Norbert

    2014-04-01

    A protocol with the potential of beating the existing distance records for conventional quantum key distribution (QKD) systems is proposed. It borrows ideas from quantum repeaters by using memories in the middle of the link, and that of measurement-device-independent QKD, which only requires optical source equipment at the user's end. For certain memories with short access times, our scheme allows a higher repetition rate than that of quantum repeaters with single-mode memories, thereby requiring lower coherence times. By accounting for various sources of nonideality, such as memory decoherence, dark counts, misalignment errors, and background noise, as well as timing issues with memories, we develop a mathematical framework within which we can compare QKD systems with and without memories. In particular, we show that with the state-of-the-art technology for quantum memories, it is potentially possible to devise memory-assisted QKD systems that, at certain distances of practical interest, outperform current QKD implementations.

  17. Forced Ion Migration for Chalcogenide Phase Change Memory Device

    Science.gov (United States)

    Campbell, Kristy A (Inventor)

    2013-01-01

    Non-volatile memory devices with two stacked layers of chalcogenide materials comprising the active memory device have been investigated for their potential as phase-change memories. The devices tested included GeTe/SnTe, Ge2Se3/SnTe, and Ge2Se3/SnSe stacks. All devices exhibited resistance switching behavior. The polarity of the applied voltage with respect to the SnTe or SnSe layer was critical to the memory switching properties, due to the electric field induced movement of either Sn or Te into the Ge-chalcogenide layer. One embodiment of the invention is a device comprising a stack of chalcogenide-containing layers which exhibit phase-change switching only after a reverse polarity voltage potential is applied across the stack causing ion movement into an adjacent layer and thus "activating" the device to act as a phase-change random access memory device or a reconfigurable electronics device when the applied voltage potential is returned to the normal polarity. Another embodiment of the invention is a device that is capable of exhibiting more than two data states.

  18. Flash radiography

    International Nuclear Information System (INIS)

    Jamet, F.

    1986-01-01

    Flash radiography is a method for recording radiographic pictures of a non-transparent high-speed phenomenon. Such events occur in a variety of fields: Ballistics, dynamic high pressure physics, detonics, industry, and medical diagnostics. The phenomena observed by flash-radiography generally move at velocities between 100 m/s and 10000 m/s. The motion blur recorded on the picture is negligible only if the duration of the X-ray pulse (or the exposure time) falls in the range 10 -8 - 10 -7 s. With a medical or industrial radiographic device, the correct blackening of a film is obtained with a current of some milliamperes and a mean exposure time of 0.1 s. From this it is deduced that the value of the current passing through a flash X-ray tube must be approximately equal to 10 4 A. These values cannot be attained in conventional X-ray tubes with a heated cathode. The production of large currents is mainly achieved by vacuum discharges and field emission. Two applications of the technique are presented: flash radiographs of shock waves, and flash X-ray diffraction. (Auth.)

  19. Electrostatically telescoping nanotube nonvolatile memory device

    International Nuclear Information System (INIS)

    Kang, Jeong Won; Jiang Qing

    2007-01-01

    We propose a nonvolatile memory based on carbon nanotubes (CNTs) serving as the key building blocks for molecular-scale computers and investigate the dynamic operations of a double-walled CNT memory element by classical molecular dynamics simulations. The localized potential energy wells achieved from both the interwall van der Waals energy and CNT-metal binding energy make the bistability of the CNT positions and the electrostatic attractive forces induced by the voltage differences lead to the reversibility of this CNT memory. The material for the electrodes should be carefully chosen to achieve the nonvolatility of this memory. The kinetic energy of the CNT shuttle experiences several rebounds induced by the collisions of the CNT onto the metal electrodes, and this is critically important to the performance of such an electrostatically telescoping CNT memory because the collision time is sufficiently long to cause a delay of the state transition

  20. Radiation Damage in Electronic Memory Devices

    Directory of Open Access Journals (Sweden)

    Irfan Fetahović

    2013-01-01

    Full Text Available This paper investigates the behavior of semiconductor memories exposed to radiation in order to establish their applicability in a radiation environment. The experimental procedure has been used to test radiation hardness of commercial semiconductor memories. Different types of memory chips have been exposed to indirect ionizing radiation by changing radiation dose intensity. The effect of direct ionizing radiation on semiconductor memory behavior has been analyzed by using Monte Carlo simulation method. Obtained results show that gamma radiation causes decrease in threshold voltage, being proportional to the absorbed dose of radiation. Monte Carlo simulations of radiation interaction with material proved to be significant and can be a good estimation tool in probing semiconductor memory behavior in radiation environment.

  1. A 72% error reduction scheme based on temperature acceleration for long-term data storage applications: Cold flash and millennium memories

    Science.gov (United States)

    Yamazaki, Senju; Iwasaki, Tomoko Ogura; Hachiya, Shogo; Takahashi, Tomonori; Takeuchi, Ken

    2016-07-01

    A solid-state drive (SSD) with 1Xnm triple-level cell (TLC) NAND flash is proposed for low cost data storage applications with long-term data-retention requirements. Specifically, cold data storage requires 20 years data-retention with 100 write/erase (W/E) cycles, whereas digital archive storage requires 1000 years retention time with 1 W/E cycle. To achieve these requirements, a flexible-nLC scheme is proposed to improve the reliability of 1Xnm TLC NAND flash (Yamazaki et al., 2015). The proposed scheme combines two schemes, n-out-of-8 level cell (nLC) (Tanakamaru et al., 2014) and asymmetric coding (AC) (Tanakamaru et al., 2012) with the addition of a vertical flag. By measuring 1Xnm TLC NAND flash memory, the proposed scheme reduces errors by 72% and 69% for digital archive and cold flash respectively, compared to the conventional nLC scheme.

  2. 3D Printed Photoresponsive Devices Based on Shape Memory Composites.

    Science.gov (United States)

    Yang, Hui; Leow, Wan Ru; Wang, Ting; Wang, Juan; Yu, Jiancan; He, Ke; Qi, Dianpeng; Wan, Changjin; Chen, Xiaodong

    2017-09-01

    Compared with traditional stimuli-responsive devices with simple planar or tubular geometries, 3D printed stimuli-responsive devices not only intimately meet the requirement of complicated shapes at macrolevel but also satisfy various conformation changes triggered by external stimuli at the microscopic scale. However, their development is limited by the lack of 3D printing functional materials. This paper demonstrates the 3D printing of photoresponsive shape memory devices through combining fused deposition modeling printing technology and photoresponsive shape memory composites based on shape memory polymers and carbon black with high photothermal conversion efficiency. External illumination triggers the shape recovery of 3D printed devices from the temporary shape to the original shape. The effect of materials thickness and light density on the shape memory behavior of 3D printed devices is quantified and calculated. Remarkably, sunlight also triggers the shape memory behavior of these 3D printed devices. This facile printing strategy would provide tremendous opportunities for the design and fabrication of biomimetic smart devices and soft robotics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Graphene based non-volatile memory devices.

    Science.gov (United States)

    Wang, Xiaomu; Xie, Weiguang; Xu, Jian-Bin

    2014-08-20

    With the continuous advance of modern electronics, the demand for non-volatile memory cells rapidly grows. As a promising material for post-silicon electronic applications, graphene non-volatile memory cells have received renewed interest due to its outstanding electronic and other physical properties. This research news briefly summarizes the recent progress in this area. Appealing research activities and technical trends are highlighted. Afterwards, requirements and aims of future graphene non-volatile memory cells that may possibly influence their commercialization are also discussed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. One bipolar transistor selector - One resistive random access memory device for cross bar memory array

    Directory of Open Access Journals (Sweden)

    R. Aluguri

    2017-09-01

    Full Text Available A bipolar transistor selector was connected in series with a resistive switching memory device to study its memory characteristics for its application in cross bar array memory. The metal oxide based p-n-p bipolar transistor selector indicated good selectivity of about 104 with high retention and long endurance showing its usefulness in cross bar RRAM devices. Zener tunneling is found to be the main conduction phenomena for obtaining high selectivity. 1BT-1R device demonstrated good memory characteristics with non-linearity of 2 orders, selectivity of about 2 orders and long retention characteristics of more than 105 sec. One bit-line pull-up scheme shows that a 650 kb cross bar array made with this 1BT1R devices works well with more than 10 % read margin proving its ability in future memory technology application.

  5. One bipolar transistor selector - One resistive random access memory device for cross bar memory array

    Science.gov (United States)

    Aluguri, R.; Kumar, D.; Simanjuntak, F. M.; Tseng, T.-Y.

    2017-09-01

    A bipolar transistor selector was connected in series with a resistive switching memory device to study its memory characteristics for its application in cross bar array memory. The metal oxide based p-n-p bipolar transistor selector indicated good selectivity of about 104 with high retention and long endurance showing its usefulness in cross bar RRAM devices. Zener tunneling is found to be the main conduction phenomena for obtaining high selectivity. 1BT-1R device demonstrated good memory characteristics with non-linearity of 2 orders, selectivity of about 2 orders and long retention characteristics of more than 105 sec. One bit-line pull-up scheme shows that a 650 kb cross bar array made with this 1BT1R devices works well with more than 10 % read margin proving its ability in future memory technology application.

  6. High Density Memory Based on Quantum Device Technology

    Science.gov (United States)

    vanderWagt, Paul; Frazier, Gary; Tang, Hao

    1995-01-01

    We explore the feasibility of ultra-high density memory based on quantum devices. Starting from overall constraints on chip area, power consumption, access speed, and noise margin, we deduce boundaries on single cell parameters such as required operating voltage and standby current. Next, the possible role of quantum devices is examined. Since the most mature quantum device, the resonant tunneling diode (RTD) can easily be integrated vertically, it naturally leads to the issue of 3D integrated memory. We propose a novel method of addressing vertically integrated bistable two-terminal devices, such as resonant tunneling diodes (RTD) and Esaki diodes, that avoids individual physical contacts. The new concept has been demonstrated experimentally in memory cells of field effect transistors (FET's) and stacked RTD's.

  7. An UV photochromic memory effect in proton-based WO3 electrochromic devices

    International Nuclear Information System (INIS)

    Zhang Yong; Lee, S.-H.; Mascarenhas, A.; Deb, S. K.

    2008-01-01

    We report an UV photochromic memory effect on a standard proton-based WO 3 electrochromic device. It exhibits two memory states, associated with the colored and bleached states of the device, respectively. Such an effect can be used to enhance device performance (increasing the dynamic range), re-energize commercial electrochromic devices, and develop memory devices

  8. An UV photochromic memory effect in proton-based WO3 electrochromic devices

    Science.gov (United States)

    Zhang, Yong; Lee, S.-H.; Mascarenhas, A.; Deb, S. K.

    2008-11-01

    We report an UV photochromic memory effect on a standard proton-based WO3 electrochromic device. It exhibits two memory states, associated with the colored and bleached states of the device, respectively. Such an effect can be used to enhance device performance (increasing the dynamic range), re-energize commercial electrochromic devices, and develop memory devices.

  9. Phase-change materials for non-volatile memory devices: from technological challenges to materials science issues

    Science.gov (United States)

    Noé, Pierre; Vallée, Christophe; Hippert, Françoise; Fillot, Frédéric; Raty, Jean-Yves

    2018-01-01

    Chalcogenide phase-change materials (PCMs), such as Ge-Sb-Te alloys, have shown outstanding properties, which has led to their successful use for a long time in optical memories (DVDs) and, recently, in non-volatile resistive memories. The latter, known as PCM memories or phase-change random access memories (PCRAMs), are the most promising candidates among emerging non-volatile memory (NVM) technologies to replace the current FLASH memories at CMOS technology nodes under 28 nm. Chalcogenide PCMs exhibit fast and reversible phase transformations between crystalline and amorphous states with very different transport and optical properties leading to a unique set of features for PCRAMs, such as fast programming, good cyclability, high scalability, multi-level storage capability, and good data retention. Nevertheless, PCM memory technology has to overcome several challenges to definitively invade the NVM market. In this review paper, we examine the main technological challenges that PCM memory technology must face and we illustrate how new memory architecture, innovative deposition methods, and PCM composition optimization can contribute to further improvements of this technology. In particular, we examine how to lower the programming currents and increase data retention. Scaling down PCM memories for large-scale integration means the incorporation of the PCM into more and more confined structures and raises materials science issues in order to understand interface and size effects on crystallization. Other materials science issues are related to the stability and ageing of the amorphous state of PCMs. The stability of the amorphous phase, which determines data retention in memory devices, can be increased by doping the PCM. Ageing of the amorphous phase leads to a large increase of the resistivity with time (resistance drift), which has up to now hindered the development of ultra-high multi-level storage devices. A review of the current understanding of all these

  10. Improved charge trapping flash device with Al2O3/HfSiO stack as blocking layer

    International Nuclear Information System (INIS)

    Zheng Zhi-Wei; Huo Zong-Liang; Zhu Chen-Xin; Xu Zhong-Guang; Liu Jing; Liu Ming

    2011-01-01

    In this paper, we investigate an Al 2 O 3 /HfSiO stack as the blocking layer of a metal—oxide—nitride—oxide—silicon-type (MONOS) memory capacitor. Compared with a memory capacitor with a single HfSiO layer as the blocking layer or an Al 2 O 3 /HfO 2 stack as the blocking layer, the sample with the Al 2 O 3 /HfSiO stack as the blocking layer shows high program/erase (P/E) speed and good data retention characteristics. These improved performances can be explained by energy band engineering. The experimental results demonstrate that the memory device with an Al 2 O 3 /HfSiO stack as the blocking layer has great potential for further high-performance nonvolatile memory applications. (interdisciplinary physics and related areas of science and technology)

  11. Multi-layered metal nanocrystals in a sol-gel spin-on-glass matrix for flash memory applications

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Meiyu Stella [Department of Chemical and Biomolecular Engineering, National University of Singapore, Block E5, 4 Engineering Drive 4, 117576 (Singapore); Globalfoundries Singapore Pte Ltd, 60 Woodlands Industrial Park D, 738406 (Singapore); Suresh, Vignesh [Department of Chemical and Biomolecular Engineering, National University of Singapore, Block E5, 4 Engineering Drive 4, 117576 (Singapore); Agency for Science, Technology and Research - A*Star, Institute of Materials Research and Engineering (IMRE), #08-03, 2 Fusionopolis Way, Innovis, 138634 (Singapore); Chan, Mei Yin [School of Materials Science and Engineering (MSE), Nanyang Technological University (NTU), 50 Nanyang Avenue, 639798 (Singapore); Ma, Yu Wei [Globalfoundries Singapore Pte Ltd, 60 Woodlands Industrial Park D, 738406 (Singapore); Lee, Pooi See [School of Materials Science and Engineering (MSE), Nanyang Technological University (NTU), 50 Nanyang Avenue, 639798 (Singapore); Krishnamoorthy, Sivashankar [Agency for Science, Technology and Research - A*Star, Institute of Materials Research and Engineering (IMRE), #08-03, 2 Fusionopolis Way, Innovis, 138634 (Singapore); Science et Analyse des Materiaux Unit (SAM), Centre de Recherche Public-Gabriel Lippmann, 41, rue du Brill, Belvaux, 4422 (Luxembourg); Srinivasan, M.P., E-mail: srinivasan.madapusi@rmit.edu.au [Department of Chemical and Biomolecular Engineering, National University of Singapore, Block E5, 4 Engineering Drive 4, 117576 (Singapore); School of Engineering, RMIT University, Building 10, Level 11, Room 14, 376-392 Swanston Street, Melbourne, Victoria, 3001 (Australia)

    2017-01-15

    A simple and low-cost process of embedding metal nanocrystals as charge storage centers within a dielectric is demonstrated to address leakage issues associated with the scaling of the tunnelling oxide in flash memories. Metal nanocrystals with high work functions (nickel, platinum and palladium) were prepared as embedded species in methyl siloxane spin-on-glass (SOG) films on silicon substrates. Sub-10 nm-sized, well-isolated, uniformly distributed, multi-layered nanocrystals with high particle densities (10{sup 11}–10{sup 12} cm{sup −2}) were formed in the films by thermal curing of the spin-coated SOG films containing the metal precursors. Capacitance-Voltage measurements performed on metal-insulator-semiconductor capacitors with the SOG films show that the presence of metal nanocrystals enhanced the memory window of the films to 2.32 V at low operating voltages of ±5 V. These SOG films demonstrated the ability to store both holes and electrons. Capacitance-time measurements show good charge retention of more than 75% after 10{sup 4} s of discharging. This work demonstrates the applicability of the low-cost in-situ sol-gel preparation in contrast to conventional methods that involve multiple and expensive processing steps. - Highlights: • Sub-10 nm sized, well-isolated, uniformly distributed nanoparticle based charge trap memories. • Preparation of multi-layer high work function metal nanocrystals at low cost. • Large memory window of 2.32 V at low operating voltages of ±5 V. • Good charge retention of more than 90% and 75% after 10{sup 3} and 10{sup 4} s of discharging respectively. • Use of a 3 nm thick tunnelling oxide in compliance with ITRS specifications.

  12. Investigation of multi-state charge-storage properties of redox-active organic molecules in silicon-molecular hybrid devices for DRAM and Flash applications

    Science.gov (United States)

    Gowda, Srivardhan Shivappa

    Molecular electronics has recently spawned a considerable amount of interest with several molecules possessing charge-conduction and charge-storage properties proposed for use in electronic devices. Hybrid silicon-molecular technology has the promise of augmenting the current silicon technology and provide for a transitional path to future molecule-only technology. The focus of this dissertation work has been on developing a class of hybrid silicon-molecular electronic devices for DRAM and Flash memory applications utilizing redox-active molecules. This work exploits the ability of molecules to store charges with single-electron precision at room temperature. The hybrid devices are fabricated by forming self-assembled monolayers of redox-active molecules on Si and oxide (SiO2 and HfO2) surfaces via formation of covalent linkages. The molecules possess discrete quantum states from which electrons can tunnel to the Si substrate at discrete applied voltages (oxidation process, cell write), leaving behind a positively charged layer of molecules. The reduction (erase) process, which is the process of electrons tunneling back from Si to the molecules, neutralizes the positively charged molecular monolayer. Hybrid silicon-molecular capacitor test structures were electrically characterized with an electrolyte gate using cyclic voltammetry (CyV) and impedance spectroscopy (CV) techniques. The redox voltages, kinetics (write/erase speeds) and charge-retention characteristics were found to be strongly dependent on the Si doping type and densities, and ambient light. It was also determined that the redox energy states in the molecules communicate with the valence band of the Si substrate. This allows tuning of write and read states by modulating minority carriers in n- and p-Si substrates. Ultra-thin dielectric tunnel barriers (SiO2, HfO2) were placed between the molecules and the Si substrate to augment charge-retention for Flash memory applications. The redox response was

  13. Terrestrial neutron-induced soft errors in advanced memory devices

    CERN Document Server

    Nakamura, Takashi; Ibe, Eishi; Yahagi, Yasuo; Kameyama, Hideaki

    2008-01-01

    Terrestrial neutron-induced soft errors in semiconductor memory devices are currently a major concern in reliability issues. Understanding the mechanism and quantifying soft-error rates are primarily crucial for the design and quality assurance of semiconductor memory devices. This book covers the relevant up-to-date topics in terrestrial neutron-induced soft errors, and aims to provide succinct knowledge on neutron-induced soft errors to the readers by presenting several valuable and unique features. Sample Chapter(s). Chapter 1: Introduction (238 KB). Table A.30 mentioned in Appendix A.6 on

  14. Non-Volatile Flash Memory Characteristics of Tetralayer Nickel-Germanide Nanocrystals Embedded Structure.

    Science.gov (United States)

    Panda, D; Panda, M

    2016-01-01

    Formation of tetralayer memory structure having nickel-germanide nanocrystals using a Ge/Ni multilayers is proposed. X-ray diffraction study shows the NiGe (002) phase formation after proper annealing. Cross sectional HRTEM clearly shows the sharpness and the size (~4-6 nm) of the stacked nanocrystals embedded in the oxide matrix. A large anti-clockwise hysteresis memory win- dow of 13.4 Volt at ± 15 Volt is observed for the optimized samples. This large memory window indicates for the MLC applications. Frequency independent C-V curve confirms about the charge storage in the nanocrystals. A good charge retention and endurance characteristics are exhibited upto 125 °C for the nonvolatile memory application.

  15. Hybrid superconducting-magnetic memory device using competing order parameters.

    Science.gov (United States)

    Baek, Burm; Rippard, William H; Benz, Samuel P; Russek, Stephen E; Dresselhaus, Paul D

    2014-05-28

    In a hybrid superconducting-magnetic device, two order parameters compete, with one type of order suppressing the other. Recent interest in ultra-low-power, high-density cryogenic memories has spurred new efforts to simultaneously exploit superconducting and magnetic properties so as to create novel switching elements having these two competing orders. Here we describe a reconfigurable two-layer magnetic spin valve integrated within a Josephson junction. Our measurements separate the suppression in the superconducting coupling due to the exchange field in the magnetic layers, which causes depairing of the supercurrent, from the suppression due to the stray magnetic field. The exchange field suppression of the superconducting order parameter is a tunable and switchable behaviour that is also scalable to nanometer device dimensions. These devices demonstrate non-volatile, size-independent switching of Josephson coupling, in magnitude as well as phase, and they may enable practical nanoscale superconducting memory devices.

  16. Memory-assisted measurement-device-independent quantum key distribution

    International Nuclear Information System (INIS)

    Panayi, Christiana; Razavi, Mohsen; Ma, Xiongfeng; Lütkenhaus, Norbert

    2014-01-01

    A protocol with the potential of beating the existing distance records for conventional quantum key distribution (QKD) systems is proposed. It borrows ideas from quantum repeaters by using memories in the middle of the link, and that of measurement-device-independent QKD, which only requires optical source equipment at the user's end. For certain memories with short access times, our scheme allows a higher repetition rate than that of quantum repeaters with single-mode memories, thereby requiring lower coherence times. By accounting for various sources of nonideality, such as memory decoherence, dark counts, misalignment errors, and background noise, as well as timing issues with memories, we develop a mathematical framework within which we can compare QKD systems with and without memories. In particular, we show that with the state-of-the-art technology for quantum memories, it is potentially possible to devise memory-assisted QKD systems that, at certain distances of practical interest, outperform current QKD implementations. (paper)

  17. Hot Flashes

    Science.gov (United States)

    Hot flashes Overview Hot flashes are sudden feelings of warmth, which are usually most intense over the face, neck and chest. Your skin might redden, as if you're blushing. Hot flashes can also cause sweating, and if you ...

  18. Bioorganic nanodots for non-volatile memory devices

    International Nuclear Information System (INIS)

    Amdursky, Nadav; Shalev, Gil; Handelman, Amir; Natan, Amir; Rosenwaks, Yossi; Litsyn, Simon; Szwarcman, Daniel; Rosenman, Gil; Roizin, Yakov

    2013-01-01

    In recent years we are witnessing an intensive integration of bio-organic nanomaterials in electronic devices. Here we show that the diphenylalanine bio-molecule can self-assemble into tiny peptide nanodots (PNDs) of ∼2 nm size, and can be embedded into metal-oxide-semiconductor devices as charge storage nanounits in non-volatile memory. For that purpose, we first directly observe the crystallinity of a single PND by electron microscopy. We use these nanocrystalline PNDs units for the formation of a dense monolayer on SiO 2 surface, and study the electron/hole trapping mechanisms and charge retention ability of the monolayer, followed by fabrication of PND-based memory cell device

  19. Professional Flash Lite Mobile Development

    CERN Document Server

    Anderson, J G

    2010-01-01

    Discover how to create Flash Lite mobile apps from the ground up. Adobe Flash is an ideal choice for developing rich interactive content for "Flash-enabled" mobile devices; and with this book, you'll learn how to create unique applications with Flash Lite. Through a series of code samples and extensive example applications, you'll explore the core concepts, key features, and best practices of the Flash Lite player. Coverage reveals various ways to develop Flash mobile content, create applications with a cross-platform programming framework based on the Model, View and Controller conc

  20. C-RAM: breaking mobile device memory barriers using the cloud

    OpenAIRE

    Pamboris, A; Pietzuch, P

    2015-01-01

    ?Mobile applications are constrained by the available memory of mobile devices. We present C-RAM, a system that uses cloud-based memory to extend the memory of mobile devices. It splits application state and its associated computation between a mobile device and a cloud node to allow applications to consume more memory, while minimising the performance impact. C-RAM thus enables developers to realise new applications or port legacy desktop applications with a large memory footprint to mobile ...

  1. Multi-objective optimization of laser cutting for flash memory modules with special shapes using grey relational analysis

    Science.gov (United States)

    Li, Chun-Hao; Tsai, Ming-Jong

    2009-07-01

    This paper presents a novel effective method for optimizing laser cutting of specially shaped electronic printed circuit board (PCB) carrier substrates of advanced integrated circuit (IC) back-end packages that have multiple performance characteristics identified using grey relational analysis (GRA). Laser cutting parameters, including laser beam parameters (average laser power and Q-switch frequency), focusing parameters (laser beam focusing spot size), and machine parameters (laser cutting speed), were optimized based on multiple performance characteristics. Some characteristics of the specially shaped flash memory module for IC packages, such as smart disk (SD) cards are verified. The characteristics of interest are the average surface roughness on a PCB substrate cross-section, and the maximum width of the heat-affected zone (HAZ). Eight experiments were conducted using GRA to optimize the settings for laser beam cutting parameters to generate various quality characteristics. Analysis of the grey relational grade indicates that parameter significance and the optimal parameter combination for the laser cutting process are identified. The analytical results from two confirmation experiments using the optimal parameters confirm that laser cutting technology can be effectively applied to cut substrates into special shapes.

  2. Radiation effect test on ADC/DAC and high density memory devices with 60Co γ-rays

    International Nuclear Information System (INIS)

    Xing Kefei; Wang Yueke; Pan Huafeng

    2006-01-01

    A test platform was constructed for 60 Co γ-ray irradiation experiment of microelectronics, with the aid of computer and a FPGA module. The tested sample devices included analog-to-digital converter AD10465, digital-to-analog converter AD9857, high density Flash memory MEF64M16 and anti-fused PROM XQR17V16, which are used in signal processing module in spaceborne systems. Evaluations were made on their ability of resisting the total dose based on the proper function criterion of the devices. The results showed that AD10465 and AD9857 ran properly after 1.59 kGy(Si) irradiation, but errors were found when MEF64M16 and XQR17V16's total ionizing dose is 0.13 kGy(Si) and 0.99 kGy(Si), respectively. (authors)

  3. RFID and Memory Devices Fabricated Integrally on Substrates

    Science.gov (United States)

    Schramm, Harry F.

    2004-01-01

    Electronic identification devices containing radio-frequency identification (RFID) circuits and antennas would be fabricated integrally with the objects to be identified, according to a proposal. That is to say, the objects to be identified would serve as substrates for the deposition and patterning of the materials of the devices used to identify them, and each identification device would be bonded to the identified object at the molecular level. Vacuum arc vapor deposition (VAVD) is the NASA derived process for depositing layers of material on the substrate. This proposal stands in contrast to the current practice of fabricating RFID and/or memory devices as wafer-based, self-contained integrated-circuit chips that are subsequently embedded in or attached to plastic cards to make smart account-information cards and identification badges. If one relies on such a chip to store data on the history of an object to be tracked and the chip falls off or out of the object, then one loses both the historical data and the means to track the object and verify its identity electronically. Also, in contrast is the manufacturing philosophy in use today to make many memory devices. Today s methods involve many subtractive processes such as etching. This proposal only uses additive methods, building RFID and memory devices from the substrate up in thin layers. VAVD is capable of spraying silicon, copper, and other materials commonly used in electronic devices. The VAVD process sprays most metals and some ceramics. The material being sprayed has a very strong bond with the substrate, whether that substrate is metal, ceramic, or even wood, rock, glass, PVC, or paper. An object to be tagged with an identification device according to the proposal must be compatible with a vacuum deposition process. Temperature is seldom an issue as the substrate rarely reaches 150 F (66 C) during the deposition process. A portion of the surface of the object would be designated as a substrate for

  4. GNSS Wristwatch Device for Networked Operations Supporting Location Based Services

    National Research Council Canada - National Science Library

    Brown, Alison; Brown, Peter K

    2008-01-01

    .... It includes a low-power GPS sensor, a flash memory, and a ZigBee wireless data link. The design of the device was selected to minimize the power drain to allow operation for extended periods of time...

  5. A triple quantum dot based nano-electromechanical memory device

    International Nuclear Information System (INIS)

    Pozner, R.; Lifshitz, E.; Peskin, U.

    2015-01-01

    Colloidal quantum dots (CQDs) are free-standing nano-structures with chemically tunable electronic properties. This tunability offers intriguing possibilities for nano-electromechanical devices. In this work, we consider a nano-electromechanical nonvolatile memory (NVM) device incorporating a triple quantum dot (TQD) cluster. The device operation is based on a bias induced motion of a floating quantum dot (FQD) located between two bound quantum dots (BQDs). The mechanical motion is used for switching between two stable states, “ON” and “OFF” states, where ligand-mediated effective interdot forces between the BQDs and the FQD serve to hold the FQD in each stable position under zero bias. Considering realistic microscopic parameters, our quantum-classical theoretical treatment of the TQD reveals the characteristics of the NVM

  6. Human sensory-evoked responses differ coincident with either "fusion-memory" or "flash-memory", as shown by stimulus repetition-rate effects

    Science.gov (United States)

    Jewett, Don L; Hart, Toryalai; Larson-Prior, Linda J; Baird, Bill; Olson, Marram; Trumpis, Michael; Makayed, Katherine; Bavafa, Payam

    2006-01-01

    Background: A new method has been used to obtain human sensory evoked-responses whose time-domain waveforms have been undetectable by previous methods. These newly discovered evoked-responses have durations that exceed the time between the stimuli in a continuous stream, thus causing an overlap which, up to now, has prevented their detection. We have named them "A-waves", and added a prefix to show the sensory system from which the responses were obtained (visA-waves, audA-waves, somA-waves). Results: When A-waves were studied as a function of stimulus repetition-rate, it was found that there were systematic differences in waveshape at repetition-rates above and below the psychophysical region in which the sensation of individual stimuli fuse into a continuity. The fusion phenomena is sometimes measured by a "Critical Fusion Frequency", but for this research we can only identify a frequency-region [which we call the STZ (Sensation-Transition Zone)]. Thus, the A-waves above the STZ differed from those below the STZ, as did the sensations. Study of the psychophysical differences in auditory and visual stimuli, as shown in this paper, suggest that different stimulus features are detected, and remembered, at stimulation rates above and below STZ. Conclusion: The results motivate us to speculate that: 1) Stimulus repetition-rates above the STZ generate waveforms which underlie "fusion-memory" whereas rates below the STZ show neuronal processing in which "flash-memory" occurs. 2) These two memories differ in both duration and mechanism, though they may occur in the same cell groups. 3) The differences in neuronal processing may be related to "figure" and "ground" differentiation. We conclude that A-waves provide a novel measure of neural processes that can be detected on the human scalp, and speculate that they may extend clinical applications of evoked response recordings. If A-waves also occur in animals, it is likely that A-waves will provide new methods for

  7. Human sensory-evoked responses differ coincident with either "fusion-memory" or "flash-memory", as shown by stimulus repetition-rate effects

    Directory of Open Access Journals (Sweden)

    Baird Bill

    2006-02-01

    Full Text Available Abstract Background: A new method has been used to obtain human sensory evoked-responses whose time-domain waveforms have been undetectable by previous methods. These newly discovered evoked-responses have durations that exceed the time between the stimuli in a continuous stream, thus causing an overlap which, up to now, has prevented their detection. We have named them "A-waves", and added a prefix to show the sensory system from which the responses were obtained (visA-waves, audA-waves, somA-waves. Results: When A-waves were studied as a function of stimulus repetition-rate, it was found that there were systematic differences in waveshape at repetition-rates above and below the psychophysical region in which the sensation of individual stimuli fuse into a continuity. The fusion phenomena is sometimes measured by a "Critical Fusion Frequency", but for this research we can only identify a frequency-region [which we call the STZ (Sensation-Transition Zone]. Thus, the A-waves above the STZ differed from those below the STZ, as did the sensations. Study of the psychophysical differences in auditory and visual stimuli, as shown in this paper, suggest that different stimulus features are detected, and remembered, at stimulation rates above and below STZ. Conclusion: The results motivate us to speculate that: 1 Stimulus repetition-rates above the STZ generate waveforms which underlie "fusion-memory" whereas rates below the STZ show neuronal processing in which "flash-memory" occurs. 2 These two memories differ in both duration and mechanism, though they may occur in the same cell groups. 3 The differences in neuronal processing may be related to "figure" and "ground" differentiation. We conclude that A-waves provide a novel measure of neural processes that can be detected on the human scalp, and speculate that they may extend clinical applications of evoked response recordings. If A-waves also occur in animals, it is likely that A-waves will provide

  8. Overview of emerging nonvolatile memory technologies.

    Science.gov (United States)

    Meena, Jagan Singh; Sze, Simon Min; Chand, Umesh; Tseng, Tseung-Yuen

    2014-01-01

    Nonvolatile memory technologies in Si-based electronics date back to the 1990s. Ferroelectric field-effect transistor (FeFET) was one of the most promising devices replacing the conventional Flash memory facing physical scaling limitations at those times. A variant of charge storage memory referred to as Flash memory is widely used in consumer electronic products such as cell phones and music players while NAND Flash-based solid-state disks (SSDs) are increasingly displacing hard disk drives as the primary storage device in laptops, desktops, and even data centers. The integration limit of Flash memories is approaching, and many new types of memory to replace conventional Flash memories have been proposed. Emerging memory technologies promise new memories to store more data at less cost than the expensive-to-build silicon chips used by popular consumer gadgets including digital cameras, cell phones and portable music players. They are being investigated and lead to the future as potential alternatives to existing memories in future computing systems. Emerging nonvolatile memory technologies such as magnetic random-access memory (MRAM), spin-transfer torque random-access memory (STT-RAM), ferroelectric random-access memory (FeRAM), phase-change memory (PCM), and resistive random-access memory (RRAM) combine the speed of static random-access memory (SRAM), the density of dynamic random-access memory (DRAM), and the nonvolatility of Flash memory and so become very attractive as another possibility for future memory hierarchies. Many other new classes of emerging memory technologies such as transparent and plastic, three-dimensional (3-D), and quantum dot memory technologies have also gained tremendous popularity in recent years. Subsequently, not an exaggeration to say that computer memory could soon earn the ultimate commercial validation for commercial scale-up and production the cheap plastic knockoff. Therefore, this review is devoted to the rapidly developing new

  9. Wearable Intrinsically Soft, Stretchable, Flexible Devices for Memories and Computing.

    Science.gov (United States)

    Rajan, Krishna; Garofalo, Erik; Chiolerio, Alessandro

    2018-01-27

    A recent trend in the development of high mass consumption electron devices is towards electronic textiles (e-textiles), smart wearable devices, smart clothes, and flexible or printable electronics. Intrinsically soft, stretchable, flexible, Wearable Memories and Computing devices (WMCs) bring us closer to sci-fi scenarios, where future electronic systems are totally integrated in our everyday outfits and help us in achieving a higher comfort level, interacting for us with other digital devices such as smartphones and domotics, or with analog devices, such as our brain/peripheral nervous system. WMC will enable each of us to contribute to open and big data systems as individual nodes, providing real-time information about physical and environmental parameters (including air pollution monitoring, sound and light pollution, chemical or radioactive fallout alert, network availability, and so on). Furthermore, WMC could be directly connected to human brain and enable extremely fast operation and unprecedented interface complexity, directly mapping the continuous states available to biological systems. This review focuses on recent advances in nanotechnology and materials science and pays particular attention to any result and promising technology to enable intrinsically soft, stretchable, flexible WMC.

  10. Electronic polymer memory devices-Easy to fabricate, difficult to understand

    International Nuclear Information System (INIS)

    Paul, Shashi; Salaoru, Iulia

    2010-01-01

    There has been a number reports on polymer memory devices for the last one decade. Polymer memory devices are fabricated by depositing a blend (an admixture of organic polymer, small organic molecules and nanoparticles) between two metal electrodes. These devices show two electrical conductance states ('1' and '0') when voltage is applied, thus rendering the structures suitable for data retention. These two states can be viewed as the realisation of memory devices. However, polymer memory devices reported so far suffer from multiple drawbacks that render their industrial implementation premature. There is a large discrepancy in the results reported by different groups. This article attempts to answer some of the questions.

  11. Numerical analysis of a polysilicon-based resistive memory device

    KAUST Repository

    Berco, Dan

    2018-03-08

    This study investigates a conductive bridge resistive memory device based on a Cu top electrode, 10-nm polysilicon resistive switching layer and a TiN bottom electrode, by numerical analysis for $$10^{3}$$103 programming and erase simulation cycles. The low and high resistive state values in each cycle are calculated, and the analysis shows that the structure has excellent retention reliability properties. The presented Cu species density plot indicates that Cu insertion occurs almost exclusively along grain boundaries resulting in a confined isomorphic conductive filament that maintains its overall shape and electric properties during cycling. The superior reliability of this structure may thus be attributed to the relatively low amount of Cu migrating into the RSL during initial formation. In addition, the results show a good match and help to confirm experimental measurements done over a previously demonstrated device.

  12. Selected Advances in Nanoelectronic Devices Logic, Memory and RF

    CERN Document Server

    Joodaki, Mojtaba

    2013-01-01

    Nanoelectronics, as a true successor of microelectronics, is certainly a major technology boomer in the 21st century. This has been shown by its several applications and also by its enormous potential to influence all areas of electronics, computers, information technology, aerospace defense, and consumer goods. Although the current semiconductor technology is projected to reach its physical limit in about a decade, nanoscience and nanotechnology promise breakthroughs for the future. The present books provides an in-depth review of the latest advances in the technology of nanoelectronic devices and their developments over the past decades. Moreover, it introduces new concepts for the realization of future nanoelectronic devices. The main focus of the book is on three fundamental branches of semiconductor products or applications: logic, memory, and RF and communication. By pointing out to the key technical challenges, important aspects and characteristics of various designs are used to illustrate mechanisms t...

  13. The future of memory

    Science.gov (United States)

    Marinella, M.

    In the not too distant future, the traditional memory and storage hierarchy of may be replaced by a single Storage Class Memory (SCM) device integrated on or near the logic processor. Traditional magnetic hard drives, NAND flash, DRAM, and higher level caches (L2 and up) will be replaced with a single high performance memory device. The Storage Class Memory paradigm will require high speed (read/write), excellent endurance (> 1012), nonvolatility (retention > 10 years), and low switching energies (memory (PCM). All of these devices show potential well beyond that of current flash technologies and research efforts are underway to improve the endurance, write speeds, and scalabilities to be on-par with DRAM. This progress has interesting implications for space electronics: each of these emerging device technologies show excellent resistance to the types of radiation typically found in space applications. Commercially developed, high density storage class memory-based systems may include a memory that is physically radiation hard, and suitable for space applications without major shielding efforts. This paper reviews the Storage Class Memory concept, emerging memory devices, and possible applicability to radiation hardened electronics for space.

  14. Transistor memory devices with large memory windows, using multi-stacking of densely packed, hydrophobic charge trapping metal nanoparticle array.

    Science.gov (United States)

    Cho, Ikjun; Kim, Beom Joon; Ryu, Sook Won; Cho, Jeong Ho; Cho, Jinhan

    2014-12-19

    Organic field-effect transistor (OFET) memories have rapidly evolved from low-cost and flexible electronics with relatively low-memory capacities to memory devices that require high-capacity memory such as smart memory cards or solid-state hard drives. Here, we report the high-capacity OFET memories based on the multilayer stacking of densely packed hydrophobic metal NP layers in place of the traditional transistor memory systems based on a single charge trapping layer. We demonstrated that the memory performances of devices could be significantly enhanced by controlling the adsorption isotherm behavior, multilayer stacking structure and hydrophobicity of the metal NPs. For this study, tetraoctylammonium (TOA)-stabilized Au nanoparticles (TOA-Au(NPs)) were consecutively layer-by-layer (LbL) assembled with an amine-functionalized poly(amidoamine) dendrimer (PAD). The formed (PAD/TOA-Au(NP))(n) films were used as a multilayer stacked charge trapping layer at the interface between the tunneling dielectric layer and the SiO2 gate dielectric layer. For a single AuNP layer (i.e. PAD/TOA-Au(NP))1) with a number density of 1.82 × 10(12) cm(-2), the memory window of the OFET memory device was measured to be approximately 97 V. The multilayer stacked OFET memory devices prepared with four Au(NP) layers exhibited excellent programmable memory properties (i.e. a large memory window (ΔV(th)) exceeding 145 V, a fast switching speed (1 μs), a high program/erase (P/E) current ratio (greater than 10(6)) and good electrical reliability) during writing and erasing over a relatively short time scale under an operation voltage of 100 V applied at the gate.

  15. Transistor memory devices with large memory windows, using multi-stacking of densely packed, hydrophobic charge trapping metal nanoparticle array

    International Nuclear Information System (INIS)

    Cho, Ikjun; Cho, Jinhan; Kim, Beom Joon; Cho, Jeong Ho; Ryu, Sook Won

    2014-01-01

    Organic field-effect transistor (OFET) memories have rapidly evolved from low-cost and flexible electronics with relatively low-memory capacities to memory devices that require high-capacity memory such as smart memory cards or solid-state hard drives. Here, we report the high-capacity OFET memories based on the multilayer stacking of densely packed hydrophobic metal NP layers in place of the traditional transistor memory systems based on a single charge trapping layer. We demonstrated that the memory performances of devices could be significantly enhanced by controlling the adsorption isotherm behavior, multilayer stacking structure and hydrophobicity of the metal NPs. For this study, tetraoctylammonium (TOA)-stabilized Au nanoparticles (TOA-Au NPs ) were consecutively layer-by-layer (LbL) assembled with an amine-functionalized poly(amidoamine) dendrimer (PAD). The formed (PAD/TOA-Au NP ) n films were used as a multilayer stacked charge trapping layer at the interface between the tunneling dielectric layer and the SiO 2 gate dielectric layer. For a single Au NP layer (i.e. PAD/TOA-Au NP ) 1 ) with a number density of 1.82 × 10 12 cm −2 , the memory window of the OFET memory device was measured to be approximately 97 V. The multilayer stacked OFET memory devices prepared with four Au NP layers exhibited excellent programmable memory properties (i.e. a large memory window (ΔV th ) exceeding 145 V, a fast switching speed (1 μs), a high program/erase (P/E) current ratio (greater than 10 6 ) and good electrical reliability) during writing and erasing over a relatively short time scale under an operation voltage of 100 V applied at the gate. (paper)

  16. Non-volatile organic transistor memory devices using the poly(4-vinylpyridine)-based supramolecular electrets.

    Science.gov (United States)

    Chou, Y-H; Chiu, Y-C; Lee, W-Y; Chen, W-C

    2015-02-14

    Supramolecular electrets consisting of poly(4-vinylpyridine) (P4VP) and conjugated molecules of phenol, 2-naphthol and 2-hydroxyanthracene were investigated for non-volatile transistor memory applications. The memory windows of these supramolecular electret devices were significantly enhanced upon increasing the π-conjugation size of the molecule. A high ON/OFF current ratio of more than 10(7) over 10(4) s was achieved on the supramolecule based memory devices.

  17. 77 FR 74222 - Certain Dynamic Random Access Memory and NAND Flash Memory Devices and Products Containing Same...

    Science.gov (United States)

    2012-12-13

    ...'') of Vaud, Switzerland; Logitech, Inc. of Fremont, California; Best Buy Co., Inc. of Richfield...,500,819; and 5,687,132. The complaint further alleges the existence of a domestic industry. The...

  18. 76 FR 55417 - In the Matter of Certain Dynamic Random Access Memory and Nand Flash Memory Devices and Products...

    Science.gov (United States)

    2011-09-07

    ... industry in the United States exists as required by subsection (a)(2) of section 337. The complainants... 1, 2, 4, 6, 9, 10, 28, and 29 of the `132 patent, and whether an industry in the United States... Choc, CH-1122, Romanelsur- Morges, Vaud, Switzerland. Logitech, Inc., 6505 Kaiser Drive, Fremont, CA...

  19. Synthesis, characterization, and non-volatile memory device application of an N-substituted heteroacene.

    Science.gov (United States)

    Wang, Chengyuan; Wang, Jiangxin; Li, Pei-Zhou; Gao, Junkuo; Tan, Si Yu; Xiong, Wei-Wei; Hu, Benlin; Lee, Pooi See; Zhao, Yanli; Zhang, Qichun

    2014-03-01

    N-substituted heteroacenes have been widely used as electroactive layers in organic electronic devices, and only a few of them have been investigated in organic resistive memory devices. Here, a novel N-substituted heteroacene 2-(4'-(diphenylamino)phenyl)-4,11-bis((triisopropylsilyl)ethynyl)-1H-imidazo[4,5-b]phenazine (DBIP) has been designed, synthesized, and characterized. Sandwich-structure memory devices based on DBIP have been fabricated and the devices show non-volatile and stable memory character with good endurance performance. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. A fast, high-endurance and scalable non-volatile memory device made from asymmetric Ta2O(5-x)/TaO(2-x) bilayer structures.

    Science.gov (United States)

    Lee, Myoung-Jae; Lee, Chang Bum; Lee, Dongsoo; Lee, Seung Ryul; Chang, Man; Hur, Ji Hyun; Kim, Young-Bae; Kim, Chang-Jung; Seo, David H; Seo, Sunae; Chung, U-In; Yoo, In-Kyeong; Kim, Kinam

    2011-07-10

    Numerous candidates attempting to replace Si-based flash memory have failed for a variety of reasons over the years. Oxide-based resistance memory and the related memristor have succeeded in surpassing the specifications for a number of device requirements. However, a material or device structure that satisfies high-density, switching-speed, endurance, retention and most importantly power-consumption criteria has yet to be announced. In this work we demonstrate a TaO(x)-based asymmetric passive switching device with which we were able to localize resistance switching and satisfy all aforementioned requirements. In particular, the reduction of switching current drastically reduces power consumption and results in extreme cycling endurances of over 10(12). Along with the 10 ns switching times, this allows for possible applications to the working-memory space as well. Furthermore, by combining two such devices each with an intrinsic Schottky barrier we eliminate any need for a discrete transistor or diode in solving issues of stray leakage current paths in high-density crossbar arrays.

  1. uFlip: Understanding Flash IO Patterns

    DEFF Research Database (Denmark)

    Bouganim, Luc; Jonsson, Bjørn; Bonnet, Philippe

    2009-01-01

    want to establish what kind of IOs should be favored (or avoided) when designing algorithms and architectures for flash-based systems. In this paper, we focus on flash IO patterns, that capture relevant distribution of IOs in time and space, and our goal is to quantify their performance. We define u......FLIP, a benchmark for measuring the response time of flash IO patterns. We also present a benchmarking methodology which takes into account the particular characteristics of flash devices. Finally, we present the results obtained by measuring eleven flash devices, and derive a set of design hints that should drive...

  2. Phase change memory

    CERN Document Server

    Qureshi, Moinuddin K

    2011-01-01

    As conventional memory technologies such as DRAM and Flash run into scaling challenges, architects and system designers are forced to look at alternative technologies for building future computer systems. This synthesis lecture begins by listing the requirements for a next generation memory technology and briefly surveys the landscape of novel non-volatile memories. Among these, Phase Change Memory (PCM) is emerging as a leading contender, and the authors discuss the material, device, and circuit advances underlying this exciting technology. The lecture then describes architectural solutions t

  3. Flash grundkursus

    DEFF Research Database (Denmark)

    Jensen, Henrik

    2008-01-01

    Flash er et programmeringssprog  og kan som sådant ikke noget i sig selv. Kursets mål er, at give den studerende et grundlæggende kendskab til Flash, så det kan bruges til præsentationer på skærm og til produktion af hjemmesider. På kurset arbejdes der med billede, grafik, lyd, video og interakti...

  4. SHADE: A Shape-Memory-Activated Device Promoting Ankle Dorsiflexion

    Science.gov (United States)

    Pittaccio, S.; Viscuso, S.; Rossini, M.; Magoni, L.; Pirovano, S.; Villa, E.; Besseghini, S.; Molteni, F.

    2009-08-01

    Acute post-stroke rehabilitation protocols include passive mobilization as a means to prevent contractures. A device (SHADE) that provides repetitive passive motion to a flaccid ankle by using shape memory alloy actuators could be of great help in providing this treatment. A suitable actuator was designed as a cartridge of approximately 150 × 20 × 15 mm, containing 2.5 m of 0.25 mm diameter NiTi wire. This actuator was activated by Joule’s effect employing a 7 s current input at 0.7 A, which provided 10 N through 76 mm displacement. Cooling and reset by natural convection took 30 s. A prototype of SHADE was assembled with two thermoplastic shells hinged together at the ankle and strapped on the shin and foot. Two actuators were fixed on the upper shell while an inextensible thread connected each NiTi wire to the foot shell. The passive ankle motion (passive range of motion, PROM) generated by SHADE was evaluated optoelectronically on three flaccid patients (58 ± 5 years old); acceptability was assessed by a questionnaire presented to further three flaccid patients (44 ± 11.5 years old) who used SHADE for 5 days, 30 min a day. SHADE was well accepted by all patients, produced good PROM, and caused no pain. The results prove that suitable limb mobilization can be produced by SMA actuators.

  5. Three-terminal resistive switching memory in a transparent vertical-configuration device

    International Nuclear Information System (INIS)

    Ungureanu, Mariana; Llopis, Roger; Casanova, Fèlix; Hueso, Luis E.

    2014-01-01

    The resistive switching phenomenon has attracted much attention recently for memory applications. It describes the reversible change in the resistance of a dielectric between two non-volatile states by the application of electrical pulses. Typical resistive switching memories are two-terminal devices formed by an oxide layer placed between two metal electrodes. Here, we report on the fabrication and operation of a three-terminal resistive switching memory that works as a reconfigurable logic component and offers an increased logic density on chip. The three-terminal memory device we present is transparent and could be further incorporated in transparent computing electronic technologies

  6. Lanthanum Gadolinium Oxide: A New Electronic Device Material for CMOS Logic and Memory Devices

    Directory of Open Access Journals (Sweden)

    Shojan P. Pavunny

    2014-03-01

    Full Text Available A comprehensive study on the ternary dielectric, LaGdO3, synthesized and qualified in our laboratory as a novel high-k dielectric material for logic and memory device applications in terms of its excellent features that include a high linear dielectric constant (k of ~22 and a large energy bandgap of ~5.6 eV, resulting in sufficient electron and hole band offsets of ~2.57 eV and ~1.91 eV, respectively, on silicon, good thermal stability with Si and lower gate leakage current densities within the International Technology Roadmap for Semiconductors (ITRS specified limits at the sub-nanometer electrical functional thickness level, which are desirable for advanced complementary metal-oxide-semiconductor (CMOS, bipolar (Bi and BiCMOS chips applications, is presented in this review article.

  7. Solution-processed flexible NiO resistive random access memory device

    Science.gov (United States)

    Kim, Soo-Jung; Lee, Heon; Hong, Sung-Hoon

    2018-04-01

    Non-volatile memories (NVMs) using nanocrystals (NCs) as active materials can be applied to soft electronic devices requiring a low-temperature process because NCs do not require a heat treatment process for crystallization. In addition, memory devices can be implemented simply by using a patterning technique using a solution process. In this study, a flexible NiO ReRAM device was fabricated using a simple NC patterning method that controls the capillary force and dewetting of a NiO NC solution at low temperature. The switching behavior of a NiO NC based memory was clearly observed by conductive atomic force microscopy (c-AFM).

  8. Status and Prospects of ZnO-Based Resistive Switching Memory Devices

    Science.gov (United States)

    Simanjuntak, Firman Mangasa; Panda, Debashis; Wei, Kung-Hwa; Tseng, Tseung-Yuen

    2016-08-01

    In the advancement of the semiconductor device technology, ZnO could be a prospective alternative than the other metal oxides for its versatility and huge applications in different aspects. In this review, a thorough overview on ZnO for the application of resistive switching memory (RRAM) devices has been conducted. Various efforts that have been made to investigate and modulate the switching characteristics of ZnO-based switching memory devices are discussed. The use of ZnO layer in different structure, the different types of filament formation, and the different types of switching including complementary switching are reported. By considering the huge interest of transparent devices, this review gives the concrete overview of the present status and prospects of transparent RRAM devices based on ZnO. ZnO-based RRAM can be used for flexible memory devices, which is also covered here. Another challenge in ZnO-based RRAM is that the realization of ultra-thin and low power devices. Nevertheless, ZnO not only offers decent memory properties but also has a unique potential to be used as multifunctional nonvolatile memory devices. The impact of electrode materials, metal doping, stack structures, transparency, and flexibility on resistive switching properties and switching parameters of ZnO-based resistive switching memory devices are briefly compared. This review also covers the different nanostructured-based emerging resistive switching memory devices for low power scalable devices. It may give a valuable insight on developing ZnO-based RRAM and also should encourage researchers to overcome the challenges.

  9. Models for Total-Dose Radiation Effects in Non-Volatile Memory

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Philip Montgomery; Wix, Steven D.

    2017-04-01

    The objective of this work is to develop models to predict radiation effects in non- volatile memory: flash memory and ferroelectric RAM. In flash memory experiments have found that the internal high-voltage generators (charge pumps) are the most sensitive to radiation damage. Models are presented for radiation effects in charge pumps that demonstrate the experimental results. Floating gate models are developed for the memory cell in two types of flash memory devices by Intel and Samsung. These models utilize Fowler-Nordheim tunneling and hot electron injection to charge and erase the floating gate. Erase times are calculated from the models and compared with experimental results for different radiation doses. FRAM is less sensitive to radiation than flash memory, but measurements show that above 100 Krad FRAM suffers from a large increase in leakage current. A model for this effect is developed which compares closely with the measurements.

  10. Metal-organic molecular device for non-volatile memory storage

    International Nuclear Information System (INIS)

    Radha, B.; Sagade, Abhay A.; Kulkarni, G. U.

    2014-01-01

    Non-volatile memory devices have been of immense research interest for their use in active memory storage in powered off-state of electronic chips. In literature, various molecules and metal compounds have been investigated in this regard. Molecular memory devices are particularly attractive as they offer the ease of storing multiple memory states in a unique way and also represent ubiquitous choice for miniaturized devices. However, molecules are fragile and thus the device breakdown at nominal voltages during repeated cycles hinders their practical applicability. Here, in this report, a synergetic combination of an organic molecule and an inorganic metal, i.e., a metal-organic complex, namely, palladium hexadecylthiolate is investigated for memory device characteristics. Palladium hexadecylthiolate following partial thermolysis is converted to a molecular nanocomposite of Pd(II), Pd(0), and long chain hydrocarbons, which is shown to exhibit non-volatile memory characteristics with exceptional stability and retention. The devices are all solution-processed and the memory action stems from filament formation across the pre-formed cracks in the nanocomposite film.

  11. Nonvolatile Memory Technology for Space Applications

    Science.gov (United States)

    Oldham, Timothy R.; Irom, Farokh; Friendlich, Mark; Nguyen, Duc; Kim, Hak; Berg, Melanie; LaBel, Kenneth A.

    2010-01-01

    This slide presentation reviews several forms of nonvolatile memory for use in space applications. The intent is to: (1) Determine inherent radiation tolerance and sensitivities, (2) Identify challenges for future radiation hardening efforts, (3) Investigate new failure modes and effects, and technology modeling programs. Testing includes total dose, single event (proton, laser, heavy ion), and proton damage (where appropriate). Test vehicles are expected to be a variety of non-volatile memory devices as available including Flash (NAND and NOR), Charge Trap, Nanocrystal Flash, Magnetic Memory (MRAM), Phase Change--Chalcogenide, (CRAM), Ferroelectric (FRAM), CNT, and Resistive RAM.

  12. Ferroelectric-gate field effect transistor memories device physics and applications

    CERN Document Server

    Ishiwara, Hiroshi; Okuyama, Masanori; Sakai, Shigeki; Yoon, Sung-Min

    2016-01-01

    This book provides comprehensive coverage of the materials characteristics, process technologies, and device operations for memory field-effect transistors employing inorganic or organic ferroelectric thin films. This transistor-type ferroelectric memory has interesting fundamental device physics and potentially large industrial impact. Among the various applications of ferroelectric thin films, the development of nonvolatile ferroelectric random access memory (FeRAM) has progressed most actively since the late 1980s and has achieved modest mass production levels for specific applications since 1995. There are two types of memory cells in ferroelectric nonvolatile memories. One is the capacitor-type FeRAM and the other is the field-effect transistor (FET)-type FeRAM. Although the FET-type FeRAM claims ultimate scalability and nondestructive readout characteristics, the capacitor-type FeRAMs have been the main interest for the major semiconductor memory companies, because the ferroelectric FET has fatal handic...

  13. Memory characteristics of silicon nitride with silicon nanocrystals as a charge trapping layer of nonvolatile memory devices

    International Nuclear Information System (INIS)

    Choi, Sangmoo; Yang, Hyundeok; Chang, Man; Baek, Sungkweon; Hwang, Hyunsang; Jeon, Sanghun; Kim, Juhyung; Kim, Chungwoo

    2005-01-01

    Silicon nitride with silicon nanocrystals formed by low-energy silicon plasma immersion ion implantation has been investigated as a charge trapping layer of a polycrystalline silicon-oxide-nitride-oxide-silicon-type nonvolatile memory device. Compared with the control sample without silicon nanocrystals, silicon nitride with silicon nanocrystals provides excellent memory characteristics, such as larger width of capacitance-voltage hysteresis, higher program/erase speed, and lower charge loss rate at elevated temperature. These improved memory characteristics are derived by incorporation of silicon nanocrystals into the charge trapping layer as additional accessible charge traps with a deeper effective trap energy level

  14. Nonvolatile write-once-read-many-times memory device with functionalized-nanoshells/PEDOT:PSS nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Avila-Nino, J.A.; Segura-Cardenas, E. [Universidad Autonoma de San Luis Potosi, Instituto de Investigacion en Comunicacion Optica, Alvaro Obregon 64 Zona Centro, 78000 SLP (Mexico); Sustaita, A.O. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216, San Luis Potosi (Mexico); Cruz-Cruz, I. [Universidad Autonoma de San Luis Potosi, Instituto de Investigacion en Comunicacion Optica, Alvaro Obregon 64 Zona Centro, 78000 SLP (Mexico); Lopez-Sandoval, R. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la presa San Jose 2055, CP 78216, San Luis Potosi (Mexico); Reyes-Reyes, M., E-mail: reyesm@iico.uaslp.mx [Universidad Autonoma de San Luis Potosi, Instituto de Investigacion en Comunicacion Optica, Alvaro Obregon 64 Zona Centro, 78000 SLP (Mexico)

    2011-03-25

    We have investigated the memory effect of the nanocomposites of functionalized carbon nanoshells (f-CNSs) mixed with poly(3,4-ethylenedioxythiophene) doped with polystyrenesulfonate (PEDOT:PSS) polymer. The f-CNSs were synthesized by the spray pyrolysis method and functionalized in situ with functional groups (OH, COOH, C-H, C-OH) with the aim of improving their compatibility in the aqueous dispersion of PEDOT:PSS. The current-voltage (I-V) sweep curves at room temperature for the Al/f-CNSs, for certain concentrations range, embedded in a PEDOT:PSS layer/Al devices showed electrical bistability for write-once-read-many-times (WORM) memory devices. The memory effect observed in the devices can be explained due to the existence of trapped charges in the f-CNSs/PEDOT:PSS layer. The carrier transport mechanisms for the memory devices is studied and discussed.

  15. Nonvolatile write-once-read-many-times memory device with functionalized-nanoshells/PEDOT:PSS nanocomposites

    International Nuclear Information System (INIS)

    Avila-Nino, J.A.; Segura-Cardenas, E.; Sustaita, A.O.; Cruz-Cruz, I.; Lopez-Sandoval, R.; Reyes-Reyes, M.

    2011-01-01

    We have investigated the memory effect of the nanocomposites of functionalized carbon nanoshells (f-CNSs) mixed with poly(3,4-ethylenedioxythiophene) doped with polystyrenesulfonate (PEDOT:PSS) polymer. The f-CNSs were synthesized by the spray pyrolysis method and functionalized in situ with functional groups (OH, COOH, C-H, C-OH) with the aim of improving their compatibility in the aqueous dispersion of PEDOT:PSS. The current-voltage (I-V) sweep curves at room temperature for the Al/f-CNSs, for certain concentrations range, embedded in a PEDOT:PSS layer/Al devices showed electrical bistability for write-once-read-many-times (WORM) memory devices. The memory effect observed in the devices can be explained due to the existence of trapped charges in the f-CNSs/PEDOT:PSS layer. The carrier transport mechanisms for the memory devices is studied and discussed.

  16. Configurable memory system and method for providing atomic counting operations in a memory device

    Science.gov (United States)

    Bellofatto, Ralph E.; Gara, Alan G.; Giampapa, Mark E.; Ohmacht, Martin

    2010-09-14

    A memory system and method for providing atomic memory-based counter operations to operating systems and applications that make most efficient use of counter-backing memory and virtual and physical address space, while simplifying operating system memory management, and enabling the counter-backing memory to be used for purposes other than counter-backing storage when desired. The encoding and address decoding enabled by the invention provides all this functionality through a combination of software and hardware.

  17. Observation of long term potentiation in papain-based memory devices

    KAUST Repository

    Bag, A.

    2014-06-01

    Biological synaptic behavior in terms of long term potentiation has been observed in papain-based (plant protein) memory devices (memristors) for the first time. Improvement in long term potentiation depends on pulse amplitude and width (duration). Continuous/repetitive dc voltage sweep leads to an increase in memristor conductivity leading to a long term memory in the \\'learning\\' processes.

  18. A non-volatile memory device consisting of graphene oxide covalently functionalized with ionic liquid.

    Science.gov (United States)

    Bhunia, Prasenjit; Hwang, Eunhee; Min, Misook; Lee, Junghyun; Seo, Sohyeon; Some, Surajit; Lee, Hyoyoung

    2012-01-21

    We introduce non-volatile resistive crossbar memory based on ionic liquid covalently functionalized on a partially reduced graphene oxide (PrGO). The write-read-erase-read (WRER) cycles were very stable after several hundred cycles and the retention time of both the ON and OFF states was stable for over 1000 s, indicating that the device we developed can function as a non-volatile memory device. This journal is © The Royal Society of Chemistry 2012

  19. Process Qualification Strategy for Advances Embedded Non Volatile Memory Technology : The Philips' 0.18um Embedded Flash Case

    NARCIS (Netherlands)

    Tao, Guoqiao; Scarpa, Andrea; van Dijk, Kitty; Kuper, Fred G.

    2003-01-01

    A qualification strategy for advanced embedded non-volatile memory technology has been revealed. This strategy consists of: a thorough understanding of the requirements, extensive use and frequent update of the FMEA (failure mode effect analysis), a qualification plan with excellent coverage of all

  20. Soluble dendrimers europium(III) β-diketonate complex for organic memory devices

    International Nuclear Information System (INIS)

    Wang Binbin; Fang Junfeng; Li Bin; You Han; Ma Dongge; Hong Ziruo; Li Wenlian; Su Zhongmin

    2008-01-01

    We report the synthesis of a soluble dendrimers europium(III) complex, tris(dibenzoylmethanato)(1,3,5-tris[2-(2'-pyridyl) benzimidazoly]methylbenzene)-europium(III), and its application in organic electrical bistable memory device. Excellent stability that ensured more than 10 6 write-read-erase-reread cycles has been performed in ambient conditions without current-induced degradation. High-density, low-cost memory, good film-firming property, fascinating thermal and morphological stability allow the application of the dendrimers europium(III) complex as an active medium in non-volatile memory devices

  1. Two-bit memory devices based on single-wall carbon nanotubes: demonstration and mechanism

    International Nuclear Information System (INIS)

    Guo Ao; Fu Yunyi; Wang Chuan; Guan Lunhui; Liu Jia; Shi Zujin; Gu Zhennan; Huang Ru; Zhang Xing

    2007-01-01

    Two-bit memory devices of SWNTs, based on the hysteresis effect, have been demonstrated for the first time. The pertinent memory behaviours seem to originate from the capacitive effect due to polarization of molecules, especially the surface-bound water molecules on SiO 2 in close proximity to carbon nanotubes. Our investigations are intimately linked with ultrahigh-density memory applications, and possibly go a long way in broadening the memory applications of SWNTs, for example from nonvolatile to volatile cells

  2. A novel junction-assisted programming scheme for Si-nanocrystal memory devices with improved performance

    Science.gov (United States)

    Jiang, Dandan; Huo, Zongliang; Zhang, Manhong; Jin, Lin; Bai, Jie; Yu, Zhaoan; Liu, Jing; Wang, Qin; Yang, Xiaonan; Wang, Yong; Zhang, Bo; Chen, Junning; Liu, Ming

    2011-11-01

    A novel drain-junction-assisted hot electron programming scheme has been proposed for Si nanocrystal memory devices. Different from the conventional channel hot electron (CHE) injection, two electron injection paths are responsible for the proposed scheme. Experimental results show that the new scheme has a nearly 1 V memory window increase and almost 300 times faster programming speed rather than the conventional CHE method. Meanwhile, improved data retention and endurance characteristics have also been achieved with the enlarged memory window, which is mainly due to less tunnel oxide degradation during the program/erase cycling. Therefore, the new scheme is shown to be more promising for Si nanocrystal memory application.

  3. Ferroelectric Thin Films Basic Properties and Device Physics for Memory Applications

    CERN Document Server

    Okuyama, Masanori

    2005-01-01

    Ferroelectric thin films continue to attract much attention due to their developing, diverse applications in memory devices, FeRAM, infrared sensors, piezoelectric sensors and actuators. This book, aimed at students, researchers and developers, gives detailed information about the basic properties of these materials and the associated device physics. All authors are acknowledged experts in the field.

  4. Magnetic Resonance Flow Velocity and Temperature Mapping of a Shape Memory Polymer Foam Device

    Energy Technology Data Exchange (ETDEWEB)

    Small IV, W; Gjersing, E; Herberg, J L; Wilson, T S; Maitland, D J

    2008-10-29

    Interventional medical devices based on thermally responsive shape memory polymer (SMP) are under development to treat stroke victims. The goals of these catheter-delivered devices include re-establishing blood flow in occluded arteries and preventing aneurysm rupture. Because these devices alter the hemodynamics and dissipate thermal energy during the therapeutic procedure, a first step in the device development process is to investigate fluid velocity and temperature changes following device deployment. A laser-heated SMP foam device was deployed in a simplified in vitro vascular model. Magnetic resonance imaging (MRI) techniques were used to assess the fluid dynamics and thermal changes associated with device deployment. Spatial maps of the steady-state fluid velocity and temperature change inside and outside the laser-heated SMP foam device were acquired. Though non-physiological conditions were used in this initial study, the utility of MRI in the development of a thermally-activated SMP foam device has been demonstrated.

  5. Device and methods for writing and erasing analog information in small memory units via voltage pulses

    Energy Technology Data Exchange (ETDEWEB)

    El Gabaly Marquez, Farid; Talin, Albert Alec

    2018-04-17

    Devices and methods for non-volatile analog data storage are described herein. In an exemplary embodiment, an analog memory device comprises a potential-carrier source layer, a barrier layer deposited on the source layer, and at least two storage layers deposited on the barrier layer. The memory device can be prepared to write and read data via application of a biasing voltage between the source layer and the storage layers, wherein the biasing voltage causes potential-carriers to migrate into the storage layers. After initialization, data can be written to the memory device by application of a voltage pulse between two storage layers that causes potential-carriers to migrate from one storage layer to another. A difference in concentration of potential carriers caused by migration of potential-carriers between the storage layers results in a voltage that can be measured in order to read the written data.

  6. Memory attacks on device-independent quantum cryptography.

    Science.gov (United States)

    Barrett, Jonathan; Colbeck, Roger; Kent, Adrian

    2013-01-04

    Device-independent quantum cryptographic schemes aim to guarantee security to users based only on the output statistics of any components used, and without the need to verify their internal functionality. Since this would protect users against untrustworthy or incompetent manufacturers, sabotage, or device degradation, this idea has excited much interest, and many device-independent schemes have been proposed. Here we identify a critical weakness of device-independent protocols that rely on public communication between secure laboratories. Untrusted devices may record their inputs and outputs and reveal information about them via publicly discussed outputs during later runs. Reusing devices thus compromises the security of a protocol and risks leaking secret data. Possible defenses include securely destroying or isolating used devices. However, these are costly and often impractical. We propose other more practical partial defenses as well as a new protocol structure for device-independent quantum key distribution that aims to achieve composable security in the case of two parties using a small number of devices to repeatedly share keys with each other (and no other party).

  7. Shape-memory polymer foam device for treating aneurysms

    Science.gov (United States)

    Ortega, Jason M.; Benett, William J.; Small, Ward; Wilson, Thomas S.; Maitland, Duncan J; Hartman, Jonathan

    2017-05-30

    A system for treating an aneurysm in a blood vessel or vein, wherein the aneurysm has a dome, an interior, and a neck. The system includes a shape memory polymer foam in the interior of the aneurysm between the dome and the neck. The shape memory polymer foam has pores that include a first multiplicity of pores having a first pore size and a second multiplicity of pores having a second pore size. The second pore size is larger than said first pore size. The first multiplicity of pores are located in the neck of the aneurysm. The second multiplicity of pores are located in the dome of the aneurysm.

  8. NAFFS: network attached flash file system for cloud storage on portable consumer electronics

    Science.gov (United States)

    Han, Lin; Huang, Hao; Xie, Changsheng

    Cloud storage technology has become a research hotspot in recent years, while the existing cloud storage services are mainly designed for data storage needs with stable high speed Internet connection. Mobile Internet connections are often unstable and the speed is relatively low. These native features of mobile Internet limit the use of cloud storage in portable consumer electronics. The Network Attached Flash File System (NAFFS) presented the idea of taking the portable device built-in NAND flash memory as the front-end cache of virtualized cloud storage device. Modern portable devices with Internet connection have built-in more than 1GB NAND Flash, which is quite enough for daily data storage. The data transfer rate of NAND flash device is much higher than mobile Internet connections[1], and its non-volatile feature makes it very suitable as the cache device of Internet cloud storage on portable device, which often have unstable power supply and intermittent Internet connection. In the present work, NAFFS is evaluated with several benchmarks, and its performance is compared with traditional network attached file systems, such as NFS. Our evaluation results indicate that the NAFFS achieves an average accessing speed of 3.38MB/s, which is about 3 times faster than directly accessing cloud storage by mobile Internet connection, and offers a more stable interface than that of directly using cloud storage API. Unstable Internet connection and sudden power off condition are tolerable, and no data in cache will be lost in such situation.

  9. Nonvolatile rewritable memory device based on solution-processable graphene/poly(3-hexylthiophene) nanocomposite

    International Nuclear Information System (INIS)

    Zhang, Li; Li, Ye; Shi, Jun; Shi, Gaoquan; Cao, Shaokui

    2013-01-01

    An electrically bistable device utilizing a nanocomposite of hexadecylamine-functionalized graphene oxide (HDAGO) with poly(3-hexylthiophene) (P3HT) is demonstrated. The device has an ITO/P3HT-HDAGO/Al sandwich structure, in which the composite film of P3HT-HDAGO was prepared by simple solution phase mixing of the exfoliated HDAGO monolayers with P3HT matrix and a spin-coating method. The memory device exhibits typical bistable electrical switching behavior and a nonvolatile rewritable memory effect, with a turn-on voltage of about 1.5 V and an ON/OFF-state current ratio of 10 5 . Under ambient conditions, both the ON and OFF states are stable under a constant voltage stress or a continuous pulse voltage stress at a read voltage of 1 V. The conduction mechanism is deduced from the modeling of the nature of currents in both states, and the electrical switching behavior can be attributed to the electric-field-induced charge transfer between P3HT and HDAGO nanosheets. - Highlights: • Nonvolatile rewritable memory effect in P3HT–graphene composite is demonstrated. • The memory device was fabricated through a simple solution processing technique. • The device shows a remarkable electrical bistable behavior and excellent stability. • Memory mechanism is deduced from the modeling of the currents in both states

  10. A Nonvolatile MOSFET Memory Device Based on Mobile Protons in SiO(2) Thin Films

    Energy Technology Data Exchange (ETDEWEB)

    Vanheusden, K.; Warren, W.L.; Devine, R.A.B.; Fleetwood, D.M.; Draper, B.L.; Schwank, J.R.

    1999-03-02

    It is shown how mobile H{sup +} ions can be generated thermally inside the oxide layer of Si/SiO{sub 2}/Si structures. The technique involves only standard silicon processing steps: the nonvolatile field effect transistor (NVFET) is based on a standard MOSFET with thermally grown SiO{sub 2} capped with a poly-silicon layer. The capped thermal oxide receives an anneal at {approximately}1100 C that enables the incorporation of the mobile protons into the gate oxide. The introduction of the protons is achieved by a subsequent 500-800 C anneal in a hydrogen-containing ambient, such as forming gas (N{sub 2}:H{sub 2} 95:5). The mobile protons are stable and entrapped inside the oxide layer, and unlike alkali ions, their space-charge distribution can be controlled and rapidly rearranged at room temperature by an applied electric field. Using this principle, a standard MOS transistor can be converted into a nonvolatile memory transistor that can be switched between normally on and normally off. Switching speed, retention, endurance, and radiation tolerance data are presented showing that this non-volatile memory technology can be competitive with existing Si-based non-volatile memory technologies such as the floating gate technologies (e.g. Flash memory).

  11. Numerical study of saturation steam/water mixture flow and flashing initial sub-cooled water flow inside throttling devices

    CERN Multimedia

    CERN. Geneva

    2016-01-01

    In this work, a Computational Fluid-Dynamics (CFD) approach to model this phenomenon inside throttling devices is proposed. To validate CFD results, different nozzle geometries are analyzed, comparing numerical results with experimental data. Two cases are studied: Case 1: saturation steam/water mixture flow inside 2D convergent-divergent nozzle (inlet, outlet and throat diameter of nozzle are 0.1213m, 0.0452m and 0.0191m respectively). In this benchmark, a range of total inle...

  12. Emerging Nonvolatile Memories to Go Beyond Scaling Limits of Conventional CMOS Nanodevices

    Directory of Open Access Journals (Sweden)

    Lei Wang

    2014-01-01

    Full Text Available Continuous dimensional scaling of the CMOS technology, along with its cost reduction, has rendered Flash memory as one of the most promising nonvolatile memory candidates during the last decade. With the Flash memory technology inevitably approaching its fundamental limits, more advanced storage nanodevices, which can probably overcome the scaling limits of Flash memory, are being explored, bringing about a series of new paradigms such as FeRAM, MRAM, PCRAM, and ReRAM. These devices have indeed exhibited better scaling capability than Flash memory while also facing their respective physical drawbacks. The consequent tradeoffs therefore drive the information storage device technology towards further advancement; as a result, new types of nonvolatile memories, including carbon memory, Mott memory, macromolecular memory, and molecular memory have been proposed. In this paper, the nanomaterials used for these four emerging types of memories and the physical principles behind the writing and reading methods in each case are discussed, along with their respective merits and drawbacks when compared with conventional nonvolatile memories. The potential applications of each technology are also briefly assessed.

  13. Resistive switching characteristics of polymer non-volatile memory devices in a scalable via-hole structure.

    Science.gov (United States)

    Kim, Tae-Wook; Choi, Hyejung; Oh, Seung-Hwan; Jo, Minseok; Wang, Gunuk; Cho, Byungjin; Kim, Dong-Yu; Hwang, Hyunsang; Lee, Takhee

    2009-01-14

    The resistive switching characteristics of polyfluorene-derivative polymer material in a sub-micron scale via-hole device structure were investigated. The scalable via-hole sub-microstructure was fabricated using an e-beam lithographic technique. The polymer non-volatile memory devices varied in size from 40 x 40 microm(2) to 200 x 200 nm(2). From the scaling of junction size, the memory mechanism can be attributed to the space-charge-limited current with filamentary conduction. Sub-micron scale polymer memory devices showed excellent resistive switching behaviours such as a large ON/OFF ratio (I(ON)/I(OFF) approximately 10(4)), excellent device-to-device switching uniformity, good sweep endurance, and good retention times (more than 10,000 s). The successful operation of sub-micron scale memory devices of our polyfluorene-derivative polymer shows promise to fabricate high-density polymer memory devices.

  14. Resistive switching characteristics of polymer non-volatile memory devices in a scalable via-hole structure

    International Nuclear Information System (INIS)

    Kim, Tae-Wook; Choi, Hyejung; Oh, Seung-Hwan; Jo, Minseok; Wang, Gunuk; Cho, Byungjin; Kim, Dong-Yu; Hwang, Hyunsang; Lee, Takhee

    2009-01-01

    The resistive switching characteristics of polyfluorene-derivative polymer material in a sub-micron scale via-hole device structure were investigated. The scalable via-hole sub-microstructure was fabricated using an e-beam lithographic technique. The polymer non-volatile memory devices varied in size from 40 x 40 μm 2 to 200 x 200 nm 2 . From the scaling of junction size, the memory mechanism can be attributed to the space-charge-limited current with filamentary conduction. Sub-micron scale polymer memory devices showed excellent resistive switching behaviours such as a large ON/OFF ratio (I ON /I OFF ∼10 4 ), excellent device-to-device switching uniformity, good sweep endurance, and good retention times (more than 10 000 s). The successful operation of sub-micron scale memory devices of our polyfluorene-derivative polymer shows promise to fabricate high-density polymer memory devices.

  15. Modeling of strain effects on the device behaviors of ferroelectric memory field-effect transistors

    International Nuclear Information System (INIS)

    Yang, Feng; Hu, Guangda; Wu, Weibing; Yang, Changhong; Wu, Haitao; Tang, Minghua

    2013-01-01

    The influence of strains on the channel current–gate voltage behaviors and memory windows of ferroelectric memory field-effect transistors (FeMFETs) were studied using an improved model based on the Landau–Devonshire theory. ‘Channel potential–gate voltage’ ferroelectric polarization and silicon surface potential diagrams were constructed for strained single-domain BaTiO 3 FeMFETs. The compressive strains can increase (or decrease) the amplitude of transistor currents and enlarge memory windows. However, tensile strains only decrease the maximum value of transistor currents and compress memory windows. Mismatch strains were found to have a significant influence on the electrical behaviors of the devices, therefore, they must be considered in FeMFET device designing. (fast track communication)

  16. Unipolar bistable switching of organic non-volatile memory devices with poly(styrene-co-styrenesulfonic acid Na).

    Science.gov (United States)

    Ji, Yongsung; Cho, Byungjin; Song, Sunghoon; Choe, Minhyeok; Kim, Tae-Wook; Kim, Joon-Seop; Choi, Byung-Sang; Lee, Takhee

    2011-02-01

    We demonstrated unipolar organic bistable memory devices with 8 x 8 cross-bar array type structure. The active material for the organic non-volatile memory devices is poly(styrene-co-styrenesulfonic acid Na) (PSSANa). From the electrical measurements of the PSSANa organic memory devices, we observed rewritable unipolar switching behaviors with a stable endurance and narrow cumulative probability. Also the PSSANa memory devices exhibited a uniform cell-to-cell switching with a high ON/OFF ratio of approximately 10(5) and good retention time of approximately 10(4) seconds without significant degradation.

  17. A novel 2-T structure memory device using a Si nanodot for embedded application

    Science.gov (United States)

    Xiaonan, Yang; Yong, Wang; Manhong, Zhang; Zongliang, Huo; Jing, Liu; Bo, Zhang; Ming, Liu

    2011-12-01

    Performance and reliability of a 2 transistor Si nanocrystal nonvolatile memory (NVM) are investigated. A good performance of the memory cell has been achieved, including a fast program/erase (P/E) speed under low voltages, an excellent data retention (maintaining for 10 years) and good endurance with a less threshold voltage shift of less than 10% after 104 P/E cycles. The data show that the device has strong potential for future embedded NVM applications.

  18. Towards the development of flexible non-volatile memories.

    Science.gov (United States)

    Han, Su-Ting; Zhou, Ye; Roy, V A L

    2013-10-11

    Flexible non-volatile memories have attracted tremendous attentions for data storage for future electronics application. From device perspective, the advantages of flexible memory devices include thin, lightweight, printable, foldable and stretchable. The flash memories, resistive random access memories (RRAM) and ferroelectric random access memory/ferroelectric field-effect transistor memories (FeRAM/FeFET) are considered as promising candidates for next generation non-volatile memory device. Here, we review the general background knowledge on device structure, working principle, materials, challenges and recent progress with the emphasis on the flexibility of above three categories of non-volatile memories. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. The effectiveness of music as a mnemonic device on recognition memory for people with multiple sclerosis.

    Science.gov (United States)

    Moore, Kimberly Sena; Peterson, David A; O'Shea, Geoffrey; McIntosh, Gerald C; Thaut, Michael H

    2008-01-01

    Research shows that people with multiple sclerosis exhibit learning and memory difficulties and that music can be used successfully as a mnemonic device to aid in learning and memory. However, there is currently no research investigating the effectiveness of music mnemonics as a compensatory learning strategy for people with multiple sclerosis. Participants with clinically definitive multiple sclerosis (N = 38) were given a verbal learning and memory test. Results from a recognition memory task were analyzed that compared learning through music (n = 20) versus learning through speech (n = 18). Preliminary baseline neuropsychological data were collected that measured executive functioning skills, learning and memory abilities, sustained attention, and level of disability. An independent samples t test showed no significant difference between groups on baseline neuropsychological functioning or on recognition task measures. Correlation analyses suggest that music mnemonics may facilitate learning for people who are less impaired by the disease. Implications for future research are discussed.

  20. Immersion and dry lithography monitoring for flash memories (after develop inspection and photo cell monitor) using a darkfield imaging inspector with advanced binning technology

    Science.gov (United States)

    Parisi, P.; Mani, A.; Perry-Sullivan, C.; Kopp, J.; Simpson, G.; Renis, M.; Padovani, M.; Severgnini, C.; Piacentini, P.; Piazza, P.; Beccalli, A.

    2009-12-01

    After-develop inspection (ADI) and photo-cell monitoring (PM) are part of a comprehensive lithography process monitoring strategy. Capturing defects of interest (DOI) in the lithography cell rather than at later process steps shortens the cycle time and allows for wafer re-work, reducing overall cost and improving yield. Low contrast DOI and multiple noise sources make litho inspection challenging. Broadband brightfield inspectors provide the highest sensitivity to litho DOI and are traditionally used for ADI and PM. However, a darkfield imaging inspector has shown sufficient sensitivity to litho DOI, providing a high-throughput option for litho defect monitoring. On the darkfield imaging inspector, a very high sensitivity inspection is used in conjunction with advanced defect binning to detect pattern issues and other DOI and minimize nuisance defects. For ADI, this darkfield inspection methodology enables the separation and tracking of 'color variation' defects that correlate directly to CD variations allowing a high-sampling monitor for focus excursions, thereby reducing scanner re-qualification time. For PM, the darkfield imaging inspector provides sensitivity to critical immersion litho defects at a lower cost-of-ownership. This paper describes litho monitoring methodologies developed and implemented for flash devices for 65nm production and 45nm development using the darkfield imaging inspector.

  1. Conjugated polymer covalently modified graphene oxide quantum dots for ternary electronic memory devices.

    Science.gov (United States)

    Fan, Fei; Zhang, Bin; Cao, Yaming; Yang, Xutong; Gu, Junwei; Chen, Yu

    2017-08-03

    Zero dimensional graphene oxide (GO) quantum dots (GOQDs) have been expected to play an important role in the development of new memory materials. When the size of GO was reduced to that of GOQDs, both the electron affinity and ionization potential of GO were found to be decreased, and this was followed by the elevation of lowest energy unoccupied molecular orbital (LUMO) energy level. This implies that the electron withdrawing ability of GOQDs is weaker than that of GO. In this work, a novel arylamine-based polyazomethine covalently functionalized graphene oxide quantum dots (TPAPAM-GOQDs), which was synthesized using an amidation reaction, was for the first time used to fabricate a ternary memory device with a configuration of gold/TPAPAM-GOQDs/indium tin oxide. The current ratio of OFF : ON-1 : ON-2 was found to be 1 : 60 : 3000. Its conductive nature was also revealed using an in situ conductive atomic force microscopy technique. This memory device could potentially increase the memory capacity of the device from the conventional 2 n to 3 n when compared to binary memory devices.

  2. Spatial memory in nonhuman primates implanted with the subdural pharmacotherapy device.

    Science.gov (United States)

    Ludvig, Nandor; Tang, Hai M; Baptiste, Shirn L; Stefanov, Dimitre G; Kral, John G

    2015-06-01

    This study investigated the possible influence of the Subdural Pharmacotherapy Device (SPD) on spatial memory in 3 adult, male bonnet macaques (Macaca radiata). The device was implanted in and above the subdural/subarachnoid space and cranium overlaying the right parietal/frontal cortex: a circuitry involved in spatial memory processing. A large test chamber, equipped with four baited and four non-baited food-ports at different locations, was used: reaches into empty food ports were counted as spatial memory errors. In this study of within-subject design, before SPD implantation (control) the animals made mean 373.3 ± 114.9 (mean ± SEM) errors in the first spatial memory test session. This value dropped to 47.7 ± 18.4 by the 8th session. After SPD implantation and alternating cycles of transmeningeal saline delivery and local cerebrospinal fluid (CSF) drainage in the implanted cortex the spatial memory error count, with the same port locations, was 33.0 ± 12.2 during the first spatial memory test session, further decreasing to 5.7 ± 3.5 by the 8th post-implantation session (Pmemory performance, which in fact included at least one completely error-free session per animal over time. The study showed that complication-free implantation and use of the SPD over the parietal and frontal cortices for months leave spatial memory processes intact in nonhuman primates. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Microwave oven fabricated hybrid memristor devices for non-volatile memory storage

    International Nuclear Information System (INIS)

    Verrelli, E; Gray, R J; O’Neill, M; Kemp, N T; Kelly, S M

    2014-01-01

    Novel hybrid non-volatile memories made using an ultra-fast microwave heating method are reported for the first time. The devices, consisting of aligned ZnO nanorods embedded in poly (methyl methacrylate), require no forming step and exhibit reliable and reproducible bipolar resistive switching at low voltages and with low power usage. We attribute these properties to a combination of the high aspect ratio of the nanorods and the polymeric hybrid structure of the device. The extremely easy, fast and low-cost solution based method of fabrication makes possible the simple and quick production of cheap memory cells. (paper)

  4. Non-volatile resistive memory devices based on solution-processed ultrathin two-dimensional nanomaterials.

    Science.gov (United States)

    Tan, Chaoliang; Liu, Zhengdong; Huang, Wei; Zhang, Hua

    2015-05-07

    Ultrathin two-dimensional (2D) nanomaterials, such as graphene and MoS2, hold great promise for electronics and optoelectronics due to their distinctive physical and electronic properties. Recent progress in high-yield, massive production of ultrathin 2D nanomaterials via various solution-based methods allows them to be easily integrated into electronic devices via solution processing techniques. Non-volatile resistive memory devices based on ultrathin 2D nanomaterials have been emerging as promising alternatives for the next-generation data storage devices due to their high flexibility, three-dimensional-stacking capability, simple structure, transparency, easy fabrication and low cost. In this tutorial review, we will summarize the recent progress in the utilization of solution-processed ultrathin 2D nanomaterials for fabrication of non-volatile resistive memory devices. Moreover, we demonstrate how to achieve excellent device performance by engineering the active layers, electrodes and/or device structure of resistive memory devices. On the basis of current status, the discussion is concluded with some personal insights into the challenges and opportunities in future research directions.

  5. Nonvolatile Electric Double-Layer Transistor Memory Devices Embedded with Au Nanoparticles.

    Science.gov (United States)

    Koo, Jaemok; Yang, Jeehye; Cho, Boeun; Jo, Hyunwoo; Lee, Keun Hyung; Kang, Moon Sung

    2018-03-21

    We present nonvolatile transistor memory devices that rely on the formation of electric double layer (EDL) at the semiconductor-electrolyte interface. The two critical functional components of the devices are the ion gel electrolyte and gold nanoparticles (NPs). The ion gel electrolyte contains ionic species for EDL formation that allow inducing charges in the semiconductor-electrolyte interface. The gold NPs inserted between the ion gel and the channel layer serve as trapping sites to the induced charges to store the electrical input signals. Two different types of gold NPs were used: one prepared using direct thermal evaporation and the other prepared using a colloidal process. The organic ligands attached onto the colloidal gold NPs prevented the escape of the trapped charges from the particles and thus enhanced the retention characteristics of the programmed/erased signals. The low-voltage-driven EDL formation resulted in a programmed/erased memory signal ratio larger than 10 3 from the nonvolatile indium-gallium-zinc oxide transistor memory devices at voltages below 10 V, which could be held for >10 5 s. The utility of the electrolytes to operate memory devices demonstrated herein should provide an alternative strategy to realize cheap, portable electronic devices powered with thin-film batteries.

  6. Robust switching characteristics of CdSe/ZnS quantum dot non-volatile memory devices.

    Science.gov (United States)

    Kannan, V; Rhee, J K

    2013-08-14

    In this paper we report Al/CdSe-ZnS core-shell quantum dot/AlOx/CdSe-ZnS core-shell quantum dot/ITO based non-volatile resistive memory devices with an ON/OFF ratio of ~1000. The facile solution processed device exhibited excellent endurance characteristics for 200,000 switching cycles. Retention tests showed good stability for over 20,000 s and the devices are reproducible. A memory operating mechanism is proposed based on charge trapping-detrapping in core-shell quantum dots with AlOx acting as a barrier leading to Coulomb blockade. I-V characteristics of a three terminal device fabricated with the additional terminal wired-out from the middle AlOx layer supports the proposed charge trapping mechanism.

  7. Device performance of ferroelectric/correlated oxide heterostructures for non-volatile memory applications

    International Nuclear Information System (INIS)

    Hoffman, J; Ahn, C H; Hong, X

    2011-01-01

    Ferroelectric field effect devices offer the possibility of non-volatile data storage. Attempts to integrate perovskite ferroelectric materials with silicon semiconductors, however, have been largely unsuccessful in creating non-volatile, nondestructive read memory elements because of difficulties in controlling the ferroelectric/semiconductor interface. Correlated oxide systems have been explored as alternative channel materials to form all-perovskite field effect devices. We examine a non-volatile memory using an electric-field-induced metal-insulator transition in PbZr 0.2 Ti 0.8 O 3 /La 1-x Sr x MnO 3 (PZT/LSMO), PZT/La 1-x Ca x MnO 3 (PZT/LCMO) and PZT/La 1-x Sr x CoO 3 (PZT/LSCO) devices. The performance of these devices in the areas of switching time and retention are discussed.

  8. Device performance of ferroelectric/correlated oxide heterostructures for non-volatile memory applications.

    Science.gov (United States)

    Hoffman, J; Hong, X; Ahn, C H

    2011-06-24

    Ferroelectric field effect devices offer the possibility of non-volatile data storage. Attempts to integrate perovskite ferroelectric materials with silicon semiconductors, however, have been largely unsuccessful in creating non-volatile, nondestructive read memory elements because of difficulties in controlling the ferroelectric/semiconductor interface. Correlated oxide systems have been explored as alternative channel materials to form all-perovskite field effect devices. We examine a non-volatile memory using an electric-field-induced metal-insulator transition in PbZr(0.2)Ti(0.8)O(3)/La(1 - x)Sr(x)MnO(3) (PZT/LSMO), PZT/La(1 - x)Ca(x)MnO(3) (PZT/LCMO) and PZT/La(1 - x)Sr(x)CoO(3) (PZT/LSCO) devices. The performance of these devices in the areas of switching time and retention are discussed.

  9. Bipolar resistive switching characteristics in tantalum nitride-based resistive random access memory devices

    International Nuclear Information System (INIS)

    Kim, Myung Ju; Jeon, Dong Su; Park, Ju Hyun; Kim, Tae Geun

    2015-01-01

    This paper reports the bipolar resistive switching characteristics of TaN x -based resistive random access memory (ReRAM). The conduction mechanism is explained by formation and rupture of conductive filaments caused by migration of nitrogen ions and vacancies; this mechanism is in good agreement with either Ohmic conduction or the Poole-Frenkel emission model. The devices exhibit that the reset voltage varies from −0.82 V to −0.62 V, whereas the set voltage ranges from 1.01 V to 1.30 V for 120 DC sweep cycles. In terms of reliability, the devices exhibit good retention (>10 5  s) and pulse-switching endurance (>10 6 cycles) properties. These results indicate that TaN x -based ReRAM devices have a potential for future nonvolatile memory devices

  10. Interface-engineered templates for molecular spin memory devices

    NARCIS (Netherlands)

    Raman, Karthik V.; Kamerbeek, Alexander M.; Mukherjee, Arup; Atodiresei, Nicolae; Sen, Tamal K.; Lazic, Predrag; Caciuc, Vasile; Michel, Reent; Stalke, Dietmar; Mandal, Swadhin K.; Bluegel, Stefan; Muenzenberg, Markus; Moodera, Jagadeesh S.

    2013-01-01

    The use of molecular spin state as a quantum of information for storage, sensing and computing has generated considerable interest in the context of next-generation data storage and communication devices(1,2), opening avenues for developing multifunctional molecular spintronics(3). Such ideas have

  11. Application of complex programmable logic devices in memory radiation effects test system

    International Nuclear Information System (INIS)

    Li Yonghong; He Chaohui; Yang Hailiang; He Baoping

    2005-01-01

    The application of the complex programmable logic device (CPLD) in electronics is emphatically discussed. The method of using software MAX + plus II and CPLD are introduced. A new test system for memory radiation effects is established by using CPLD devices-EPM7128C84-15. The old test system's function are realized and, moreover, a number of small scale integrated circuits are reduced and the test system's reliability is improved. (authors)

  12. Fabrication of flexible, all-reduced graphene oxide non-volatile memory devices.

    Science.gov (United States)

    Liu, Juqing; Yin, Zongyou; Cao, Xiehong; Zhao, Fei; Wang, Lianhui; Huang, Wei; Zhang, Hua

    2013-01-11

    A flexible, all reduced graphene oxide non-volatile memory device, with lightly reduced GO as an active layer and highly reduced GO as both top and bottom electrodes, is fabricated by a full-solution process and its performance is characterized. It provides a convenient method to construct other all-carbon devices. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Growth of Si nanocrystals on alumina and integration in memory devices

    Science.gov (United States)

    Baron, T.; Fernandes, A.; Damlencourt, J. F.; De Salvo, B.; Martin, F.; Mazen, F.; Haukka, S.

    2003-06-01

    We present a detailed study of the growth of Si quantum dots (Si QDs) by low pressure chemical vapor deposition on alumina dielectric deposited by atomic layer deposition. The Si QDs density is very high, 1012 cm-2, for a mean diameter between 5 and 10 nm. Al2O3/Si QD stacks have been integrated in memory devices as granular floating gate. The devices demonstrate good charge storage and data retention characteristics.

  14. Spatially resolved Raman spectroelectrochemistry of solid-state polythiophene/viologen memory devices.

    Science.gov (United States)

    Kumar, Rajesh; Pillai, Rajesh G; Pekas, Nikola; Wu, Yiliang; McCreery, Richard L

    2012-09-12

    A three terminal molecular memory device was monitored with in situ Raman spectroscopy during bias-induced switching between two metastable states having different conductivity. The device structure is similar to that of a polythiophene field effect transistor, but ethylviologen perchlorate was added to provide a redox counter-reaction to accompany polythiophene redox reactions. The conductivity of the polythiophene layer was reversibly switched between high and low conductance states with a "write/erase" (W/E) bias, while a separate readout circuit monitored the polymer conductance. Raman spectroscopy revealed reversible polythiophene oxidation to its polaron form accompanied by a one-electron viologen reduction. "Write", "read", and "erase" operations were repeatable, with only minor degradation of response after 200 W/E cycles. The devices exhibited switching immediately after fabrication and did not require an "electroforming" step required in many types of memory devices. Spatially resolved Raman spectroscopy revealed polaron formation throughout the polymer layer, even away from the electrodes in the channel and drain regions, indicating that thiophene oxidation "propagates" by growth of the conducting polaron form away from the source electrode. The results definitively demonstrate concurrent redox reactions of both polythiophene and viologen in solid-state devices and correlate such reactions with device conductivity. The mechanism deduced from spectroscopic and electronic monitoring should guide significant improvements in memory performance.

  15. Configurable Resistive Switching between Memory and Threshold Characteristics for Protein-Based Devices

    KAUST Repository

    Wang, Hong

    2015-05-01

    The employ of natural biomaterials as the basic building blocks of electronic devices is of growing interest for biocompatible and green electronics. Here, resistive switching (RS) devices based on naturally silk protein with configurable functionality are demonstrated. The RS type of the devices can be effectively and exactly controlled by controlling the compliance current in the set process. Memory RS can be triggered by a higher compliance current, while threshold RS can be triggered by a lower compliance current. Furthermore, two types of memory devices, working in random access and WORM modes, can be achieved with the RS effect. The results suggest that silk protein possesses the potential for sustainable electronics and data storage. In addition, this finding would provide important guidelines for the performance optimization of biomaterials based memory devices and the study of the underlying mechanism behind the RS effect arising from biomaterials. Resistive switching (RS) devices with configurable functionality based on protein are successfully achieved. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Electronic memory devices based on the chalcone with negative electrostatic potential regions

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Bao-Long; Sun, Ru; Ge, Jian-Feng, E-mail: ge_jianfeng@hotmail.com; Wang, Dong; Li, Hua; Lu, Jian-Mei, E-mail: lujm@suda.edu.cn

    2013-10-01

    The molecular electrostatic potential (ESP) properties were used for the explanation of organic electric memory ability. Several chalcone compounds, owning a negative ESP region locates at the oxygen atom, were selected in this paper to validate the selection of compounds for organic memory materials. The synthesis, characterization, fabrication of the organic memory devices and the electrical properties for them were reported, and they were shown as WORM (write once read many times) type memory devices. The molecular geometries were optimized by the addition of a changeable electric field in the x direction inside the molecules using FF-DFT (Finite Field-Density Functionary Theory) method. The relationship between ESP of the molecules under different electric field and the property was discussed, and the mechanisms associated with the memory effect were also elucidated from DFT calculation results. - Highlights: • The molecular electrostatic potential (ESP) properties were used. • The chalcone compounds were used for the WORM type device. • The molecular geometries were optimized by the addition of a changeable electric field in the x direction. • The structure–property relationship was discussed.

  17. A study of selenium nanoparticles as charge storage element for flexible semi-transparent memory devices

    Science.gov (United States)

    Alotaibi, Sattam; Nama Manjunatha, Krishna; Paul, Shashi

    2017-12-01

    Flexible Semi-Transparent electronic memory would be useful in coming years for integrated flexible transparent electronic devices. However, attaining such flexibility and semi-transparency leads to the boundaries in material composition. Thus, impeding processing speed and device performance. In this work, we present the use of inorganic stable selenium nanoparticles (Se-NPs) as a storage element and hydrogenated amorphous carbon (a-C:H) as an insulating layer in two terminal non-volatile physically flexible and semi-transparent capacitive memory devices (2T-NMDs). Furthermore, a-C:H films can be deposited at very low temperature (memory on a flexible substrate. Moreover, the memory behaviour of the Se-NPs was found to be more distinct than those of the semiconductor and metal nanostructures due to higher work function compared to the commonly used semiconductor and metal species. The memory behaviour was observed from the hysteresis of current-voltage (I-V) measurements while the two distinguishable electrical conductivity states (;0; and "1") were studied by current-time (I-t) measurements.

  18. Exploration of Uninitialized Configuration Memory Space for Intrinsic Identification of Xilinx Virtex-5 FPGA Devices

    Directory of Open Access Journals (Sweden)

    Oliver Sander

    2012-01-01

    Full Text Available SRAM-based fingerprinting uses deviations in power-up behaviour caused by the CMOS fabrication process to identify distinct devices. This method is a promising technique for unique identification of physical devices. In the case of SRAM-based hardware reconfigurable devices such as FPGAs, the integrated SRAM cells are often initialized automatically at power-up, sweeping potential identification data. We demonstrate an approach to utilize unused parts of configuration memory space for device identification. Based on a total of over 200,000 measurements on nine Xilinx Virtex-5 FPGAs, we show that the retrieved values have promising properties with respect to consistency on one device, variety between different devices, and stability considering temperature variation and aging.

  19. Photo-Induced Multiple-State Memory Behaviour in Non-Volatile Bipolar Resistive-Switching Devices.

    Science.gov (United States)

    Zhang, Xuejiao; Xu, Zhiwei; Sun, Bai; Liu, Jianjun; Cao, Yanyan; Qiao, Haixia; Huang, Yong; Pang, Xiaofeng

    2018-04-01

    The recent discovery of non-volatile resistive-switching memory is a promising phenomenon for the semiconductor industry and electronic device technology. In our work, CaWO4 nanoparticles were synthesised through a one-step hydrothermal reaction. A resistive-switching memory device with Ag/CaWO4/fluorine-doped tin oxide structure was prepared. This device presents photo-induced multiple-state memory behaviour at room temperature. This study is valuable for exploring multi-functional materials and their applications in photo-controlled multiple-state non-volatile memories.

  20. Non-volatile transistor memory devices using charge storage cross-linked core-shell nanoparticles.

    Science.gov (United States)

    Lo, Chen-Tsyr; Watanabe, Yu; Oya, Hiroshi; Nakabayashi, Kazuhiro; Mori, Hideharu; Chen, Wen-Chang

    2016-06-07

    Solution processable cross-linked core-shell poly[poly(ethylene glycol)methylether methacrylate]-block-poly(2,5-dibromo-3-vinylthiophene) (poly(PEGMA)m-b-poly(DB3VT)n) nanoparticles are firstly explored as charge storage materials for transistor-type memory devices owing to their efficient and controllable ability in electric charge transfer and trapping.

  1. Composition-dependent nanoelectronics of amido-phenazines: non-volatile RRAM and WORM memory devices.

    Science.gov (United States)

    Maiti, Dilip K; Debnath, Sudipto; Nawaz, Sk Masum; Dey, Bapi; Dinda, Enakhi; Roy, Dipanwita; Ray, Sudipta; Mallik, Abhijit; Hussain, Syed A

    2017-10-17

    A metal-free three component cyclization reaction with amidation is devised for direct synthesis of DFT-designed amido-phenazine derivative bearing noncovalent gluing interactions to fabricate organic nanomaterials. Composition-dependent organic nanoelectronics for nonvolatile memory devices are discovered using mixed phenazine-stearic acid (SA) nanomaterials. We discovered simultaneous two different types of nonmagnetic and non-moisture sensitive switching resistance properties of fabricated devices utilizing mixed organic nanomaterials: (a) sample-1(8:SA = 1:3) is initially off, turning on at a threshold, but it does not turn off again with the application of any voltage, and (b) sample-2 (8:SA = 3:1) is initially off, turning on at a sharp threshold and off again by reversing the polarity. No negative differential resistance is observed in either type. These samples have different device implementations: sample-1 is attractive for write-once-read-many-times memory devices, such as novel non-editable database, archival memory, electronic voting, radio frequency identification, sample-2 is useful for resistive-switching random access memory application.

  2. High-performance nonvolatile Al/AlOx/CdTe:Sb nanowire memory device

    International Nuclear Information System (INIS)

    Xie Chao; Wu Yucheng; Nie Biao; Zhu Long; Zeng Longhui; Yu Yongqiang; Wang Xianhe; Luo Linbao; Fang Qunling

    2013-01-01

    Here we demonstrate a room temperature processed nonvolatile memory device based on an Al/AlO x /CdTe:Sb nanowire (NW) heterojunction. Electrical analysis shows an echelon hysteresis composed of a high-resistance state (HRS) and a low-resistance state (LRS), which can allow it to write and erase data from the device. The conductance ratio is as high as 10 6 , with a retention time of 3 × 10 4 s. Moreover, the SET voltages ranged from +6 to +8 V, whilst the RESET voltage ∼0 V. In addition, flexible memory nano-devices on PET substrate with comparable switching performance at bending condition were fabricated. XPS analysis of the Al/AlO x /CdTe:Sb NW heterojunction after controlled Ar + bombardment reveals that this memory behavior is associated with the presence of ultra-thin AlO x film. This Al/AlO x /CdTe:Sb NW heterojunction will open up opportunities for new memory devices with different configurations. (paper)

  3. Controlled charge trapping by molybdenum disulphide and graphene in ultrathin heterostructured memory devices.

    Science.gov (United States)

    Choi, Min Sup; Lee, Gwan-Hyoung; Yu, Young-Jun; Lee, Dae-Yeong; Lee, Seung Hwan; Kim, Philip; Hone, James; Yoo, Won Jong

    2013-01-01

    Atomically thin two-dimensional materials have emerged as promising candidates for flexible and transparent electronic applications. Here we show non-volatile memory devices, based on field-effect transistors with large hysteresis, consisting entirely of stacked two-dimensional materials. Graphene and molybdenum disulphide were employed as both channel and charge-trapping layers, whereas hexagonal boron nitride was used as a tunnel barrier. In these ultrathin heterostructured memory devices, the atomically thin molybdenum disulphide or graphene-trapping layer stores charge tunnelled through hexagonal boron nitride, serving as a floating gate to control the charge transport in the graphene or molybdenum disulphide channel. By varying the thicknesses of two-dimensional materials and modifying the stacking order, the hysteresis and conductance polarity of the field-effect transistor can be controlled. These devices show high mobility, high on/off current ratio, large memory window and stable retention, providing a promising route towards flexible and transparent memory devices utilizing atomically thin two-dimensional materials.

  4. Nonvolatile memory device using gold nanoparticles covalently bound to reduced graphene oxide.

    Science.gov (United States)

    Cui, Peng; Seo, Sohyeon; Lee, Junghyun; Wang, Luyang; Lee, Eunkyo; Min, Misook; Lee, Hyoyoung

    2011-09-27

    Nonvolatile memory devices using gold nanoparticles (AuNPs) and reduced graphene oxide (rGO) sheets were fabricated in both horizontal and vertical structures. The horizontal memory device, in which a singly and doubly overlayered semiconducting rGO channel was formed by simply using a spin-casting technique to connect two gold electrodes, was designed for understanding the origin of charging effects. AuNPs were chemically bound to the rGO channel through a π-conjugated molecular linker. The π-conjugated bifunctional molecular linker, 4-mercapto-benzenediazonium tetrafluoroborate (MBDT) salt, was newly synthesized and used as a molecular bridge to connect the AuNPs and rGOs. By using a self-assembly technique, the diazonium functional group of the MBDT molecular linker was spontaneously immobilized on the rGOs. Then, the monolayered AuNPs working as capacitors were covalently connected to the thiol groups of the MBDT molecules, which were attached to rGOs (AuNP-frGO). These covalent bonds were confirmed by XPS analyses. The current-voltage characteristics of both the horizontal and vertical AuNP-frGO memory devices showed noticeable nonlinear hysteresis, stable write-multiple read-erase-multiple read cycles over 1000 s, and a long retention time over 700 s. In addition, the vertical AuNP-frGO memory device showed a large current ON/OFF ratio and high stability. © 2011 American Chemical Society

  5. Polymer ferroelectric field-effect memory device with SnO channel layer exhibits record hole mobility

    KAUST Repository

    Caraveo-Frescas, Jesus Alfonso

    2014-06-10

    Here we report for the first time a hybrid p-channel polymer ferroelectric field-effect transistor memory device with record mobility. The memory device, fabricated at 200C on both plastic polyimide and glass substrates, uses ferroelectric polymer P(VDF-TrFE) as the gate dielectric and transparent p-type oxide (SnO) as the active channel layer. A record mobility of 3.3 cm 2V-1s-1, large memory window (~16 V), low read voltages (~-1 V), and excellent retention characteristics up to 5000 sec have been achieved. The mobility achieved in our devices is over 10 times higher than previously reported polymer ferroelectric field-effect transistor memory with p-type channel. This demonstration opens the door for the development of non-volatile memory devices based on dual channel for emerging transparent and flexible electronic devices.

  6. A bio-inspired memory device based on interfacing Physarum polycephalum with an organic semiconductor

    Energy Technology Data Exchange (ETDEWEB)

    Romeo, Agostino; Dimonte, Alice; Tarabella, Giuseppe; D’Angelo, Pasquale, E-mail: dangelo@imem.cnr.it, E-mail: iannotta@imem.cnr.it; Erokhin, Victor; Iannotta, Salvatore, E-mail: dangelo@imem.cnr.it, E-mail: iannotta@imem.cnr.it [IMEM-CNR, Institute of Materials for Electronics and Magnetism-National Research Council, Parma 43124 (Italy)

    2015-01-01

    The development of devices able to detect and record ion fluxes is a crucial point in order to understand the mechanisms that regulate communication and life of organisms. Here, we take advantage of the combined electronic and ionic conduction properties of a conducting polymer to develop a hybrid organic/living device with a three-terminal configuration, using the Physarum polycephalum Cell (PPC) slime mould as a living bio-electrolyte. An over-oxidation process induces a conductivity switch in the polymer, due to the ionic flux taking place at the PPC/polymer interface. This behaviour endows a current-depending memory effect to the device.

  7. Low-energy Resistive Random Access Memory Devices with No Need for a Compliance Current

    OpenAIRE

    Xu, Zedong; Yu, Lina; Wu, Yong; Dong, Chang; Deng, Ning; Xu, Xiaoguang; Miao, J.; Jiang, Yong

    2015-01-01

    A novel resistive random access memory device is designed with SrTiO3/ La2/3Sr1/3MnO3 (LSMO)/MgAl2O4 (MAO)/Cu structure, in which metallic epitaxial LSMO is employed as the bottom electrode rather than traditional metal materials. In this device, the critical external compliance current is no longer necessary due to the high self-resistance of LSMO. The LMSO bottom electrode can act as a series resistor to offer a compliance current during the set process. Besides, the device also has excelle...

  8. Fabrication of spray-printed organic non-volatile memory devices for low cost electronic applications

    International Nuclear Information System (INIS)

    Cha, An-Na; Ji, Yongsung; Lee, Sang-A; Noh, Yong-Young; Na, Seok-In; Bae, Sukang; Lee, Sanghyun; Kim, Tae-Wook

    2015-01-01

    Highlights: • PS:PCBM-based organic non-volatile memory devices was fabricated using spray printing. • The thickness of the film was controlled by adjusting the concentration of the PS:PCBM solutions. • The roughness of spray-printed films was poorer than that of the spin-coated film. • The minimum thickness of the printed film influenced the memory behavior more than the surface roughness. • The spray printed PS:PCBM showed excellent unipolar switching, reliability, retention, and endurance characteristics. - Abstract: We fabricated polystyrene (PS) and 6-phenyl-C61 butyric acid methyl ester (PCBM) based organic non-volatile memory devices using a spray printing technique. Due to the distinct operational properties of this technique, significant differences were observed in the macro- and microscopic features (e.g., the film quality and surface roughness) of the devices. The thickness of the film was successfully controlled by adjusting the concentration of the PS:PCBM solutions sprayed. Although the roughness of the spray-printed films was poorer than that of the spin-coated film, negligible differences were observed in the basic memory characteristics (e.g., the operation voltage range, turn on and off voltage, retention and endurance). In particular, the printing-based organic memory devices were successfully switched, as exhibited by the on/off ratio greater than two orders of magnitude at 0.3 V read voltage. The resistance state of all of the devices was maintained for more than 10 4 s, indicating their non-volatile characteristics

  9. Novel spintronics devices for memory and logic: prospects and challenges for room temperature all spin computing

    Science.gov (United States)

    Wang, Jian-Ping

    An energy efficient memory and logic device for the post-CMOS era has been the goal of a variety of research fields. The limits of scaling, which we expect to reach by the year 2025, demand that future advances in computational power will not be realized from ever-shrinking device sizes, but rather by innovative designs and new materials and physics. Magnetoresistive based devices have been a promising candidate for future integrated magnetic computation because of its unique non-volatility and functionalities. The application of perpendicular magnetic anisotropy for potential STT-RAM application was demonstrated and later has been intensively investigated by both academia and industry groups, but there is no clear path way how scaling will eventually work for both memory and logic applications. One of main reasons is that there is no demonstrated material stack candidate that could lead to a scaling scheme down to sub 10 nm. Another challenge for the usage of magnetoresistive based devices for logic application is its available switching speed and writing energy. Although a good progress has been made to demonstrate the fast switching of a thermally stable magnetic tunnel junction (MTJ) down to 165 ps, it is still several times slower than its CMOS counterpart. In this talk, I will review the recent progress by my research group and my C-SPIN colleagues, then discuss the opportunities, challenges and some potential path ways for magnetoresitive based devices for memory and logic applications and their integration for room temperature all spin computing system.

  10. Memory effects in a Al/Ti:HfO2/CuPc metal-oxide-semiconductor device

    Science.gov (United States)

    Tripathi, Udbhav; Kaur, Ramneek

    2016-05-01

    Metal oxide semiconductor structured organic memory device has been successfully fabricated. Ti doped hafnium oxide (Ti:HfO2) nanoparticles has been fabricated by precipitation method and further calcinated at 800 °C. Copper phthalocyanine, a hole transporting material has been utilized as an organic semiconductor. The electrical properties of the fabricated device have been studied by measuring the current-voltage and capacitance-voltage characteristics. The amount of charge stored in the nanoparticles has been calculated by using flat band condition. This simple approach for fabricating MOS memory device has opens up opportunities for the development of next generation memory devices.

  11. 76 FR 4375 - In the Matter of Certain MLC Flash Memory Devices and Products Containing Same; Notice of...

    Science.gov (United States)

    2011-01-25

    ... Commission's notice of investigation named Samsung Electronics Co., Ltd, Samsung Electronics America, Inc., Samsung Semiconductor, Inc., Samsung Telecommunications America, LLC (collectively ``Samsung''); Apple..., BTG, Samsung, and the Covington Respondents filed a joint motion to terminate the investigation as to...

  12. CMOS Compatible Nonvolatile Memory Devices Based on SiO2/Cu/SiO2 Multilayer Films

    Science.gov (United States)

    Wang, Yan; Liu, Qi; Lu, Hang-Bing; Long, Shi-Bing; Zhang, Sen; Li, Ying-Tao; Lian, Wen-Tai; Yang, Jian-Hong; Liu, Ming

    2011-07-01

    We systematically investigate the resistive switching characteristics of SiO2 films with a Cu/SiO2/Cu/SiO2/Pt multilayer structure. The device exhibits good resistive switching performances, including a high ON/OFF resistance ratio (>103), good retention characteristic (>104s), satisfactory switching endurance (>200 cycles), a fast programming speed (<100 ns) and a high device yield (~100%). Considering these results, SiO2-based memories have highly promising applications for nonvolatile memory devices.

  13. Feasibility study of molecular memory device based on DNA using methylation to store information

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Liming; Al-Dirini, Feras [Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville 3010 (Australia); Center for Neural Engineering (CfNE), The University of Melbourne, Carlton 3053 (Australia); National ICT Australia, The University of Melbourne, Parkville 3010 (Australia); Qiu, Wanzhi; Skafidas, Efstratios, E-mail: sskaf@unimelb.edu.au [Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville 3010 (Australia); Center for Neural Engineering (CfNE), The University of Melbourne, Carlton 3053 (Australia); Hossain, Faruque M. [Center for Neural Engineering (CfNE), The University of Melbourne, Carlton 3053 (Australia); Evans, Robin [Department of Electrical and Electronic Engineering, The University of Melbourne, Parkville 3010 (Australia)

    2016-07-14

    DNA, because of its robustness and dense information storage capability, has been proposed as a potential candidate for next-generation storage media. However, encoding information into the DNA sequence requires molecular synthesis technology, which to date is costly and prone to synthesis errors. Reading the DNA strand information is also complex. Ideally, DNA storage will provide methods for modifying stored information. Here, we conduct a feasibility study investigating the use of the DNA 5-methylcytosine (5mC) methylation state as a molecular memory to store information. We propose a new 1-bit memory device and study, based on the density functional theory and non-equilibrium Green's function method, the feasibility of electrically reading the information. Our results show that changes to methylation states lead to changes in the peak of negative differential resistance which can be used to interrogate memory state. Our work demonstrates a new memory concept based on methylation state which can be beneficial in the design of next generation DNA based molecular electronic memory devices.

  14. Feasibility study of molecular memory device based on DNA using methylation to store information

    International Nuclear Information System (INIS)

    Jiang, Liming; Al-Dirini, Feras; Qiu, Wanzhi; Skafidas, Efstratios; Hossain, Faruque M.; Evans, Robin

    2016-01-01

    DNA, because of its robustness and dense information storage capability, has been proposed as a potential candidate for next-generation storage media. However, encoding information into the DNA sequence requires molecular synthesis technology, which to date is costly and prone to synthesis errors. Reading the DNA strand information is also complex. Ideally, DNA storage will provide methods for modifying stored information. Here, we conduct a feasibility study investigating the use of the DNA 5-methylcytosine (5mC) methylation state as a molecular memory to store information. We propose a new 1-bit memory device and study, based on the density functional theory and non-equilibrium Green's function method, the feasibility of electrically reading the information. Our results show that changes to methylation states lead to changes in the peak of negative differential resistance which can be used to interrogate memory state. Our work demonstrates a new memory concept based on methylation state which can be beneficial in the design of next generation DNA based molecular electronic memory devices.

  15. BE-SONOS flash memory along with metal gate and high-k dielectrics in tunnel barrier and its impact on charge retention dynamics

    Science.gov (United States)

    Jain, Sonal; Gupta, Deepika; Neema, Vaibhav; Vishwakarma, Santosh

    2016-03-01

    We investigate the effect of a high-k dielectric in the tunnel layer to improve the erase speed-retention trade-off. Here, the proposed stack in the tunnel layer is AlLaO3/HfAlO/SiO2. These proposed materials possess low valence band offset with high permittivity to improve both the erase speed and retention time in barrier engineered silicon-oxide-nitride-oxide-silicon (BE-SONOS). In the proposed structure HfAlO and AlLaO3 replace Si3N4 and the top SiO2 layer in a conventional oxide/nitride/oxide (ONO) tunnel stack. Due to the lower conduction band offset (CBO) and high permittivity of the proposed material in the tunnel layer, it offers better program/erase (P/E) speed and retention time. In this work the gate length is also scaled down from 220 to 55 nm to observe the effect of high-k materials while scaling, for the same equivalent oxide thickness (EOT). We found that the scaling down of the gate length has a negligible impact on the memory window of the devices. Hence, various investigated tunnel oxide stacks possess a good memory window with a charge retained up to 87.4% (at room temperature) after a period of ten years. We also examine the use of a metal gate instead of a polysilicon gate, which shows improved P/E speed and retention time.

  16. BE-SONOS flash memory along with metal gate and high-k dielectrics in tunnel barrier and its impact on charge retention dynamics

    International Nuclear Information System (INIS)

    Jain, Sonal; Neema, Vaibhav; Gupta, Deepika; Vishwakarma, Santosh

    2016-01-01

    We investigate the effect of a high-k dielectric in the tunnel layer to improve the erase speed-retention trade-off. Here, the proposed stack in the tunnel layer is AlLaO 3 /HfAlO/SiO 2 . These proposed materials possess low valence band offset with high permittivity to improve both the erase speed and retention time in barrier engineered silicon-oxide-nitride-oxide-silicon (BE-SONOS). In the proposed structure HfAlO and AlLaO 3 replace Si 3 N 4 and the top SiO 2 layer in a conventional oxide/nitride/oxide (ONO) tunnel stack. Due to the lower conduction band offset (CBO) and high permittivity of the proposed material in the tunnel layer, it offers better program/erase (P/E) speed and retention time. In this work the gate length is also scaled down from 220 to 55 nm to observe the effect of high-k materials while scaling, for the same equivalent oxide thickness (EOT). We found that the scaling down of the gate length has a negligible impact on the memory window of the devices. Hence, various investigated tunnel oxide stacks possess a good memory window with a charge retained up to 87.4% (at room temperature) after a period of ten years. We also examine the use of a metal gate instead of a polysilicon gate, which shows improved P/E speed and retention time. (paper)

  17. Oligosaccharide Carbohydrate Dielectrics toward High-Performance Non-volatile Transistor Memory Devices.

    Science.gov (United States)

    Chiu, Yu-Cheng; Sun, Han-Sheng; Lee, Wen-Ya; Halila, Sami; Borsali, Redouane; Chen, Wen-Chang

    2015-10-28

    Oligosaccharides are one of the most promising biomaterials because they are abundant, renewable, diversified, and biosourced. The use of oligo- or polysaccharides for high-performance non-volatile organic field-effect-transistor memory is demonstrated herein. The charge-storage mechanism is attributed to charged hydroxyl groups that induce stronger hydrogen bonding, thus leading to the stabilization of trapped charges. This study reveals a promising future for green memory devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Next generation Associative Memory devices for the FTK tracking processor of the ATLAS experiment

    CERN Document Server

    Andreani, A; The ATLAS collaboration; Beccherle, B; Beretta, M; Citterio, M; Crescioli, F; Colombo, A; Giannetti, P; Liberali, V; Shojaii, J; Stabile, A

    2013-01-01

    The AMchip is a VLSI device that implements the associative memory function, a special content addressable memory specifically designed for high energy physics applications and first used in the CDF experiment at Tevatron. The 4th generation of AMchip has been developed for the core pattern recognition stage of the Fast TracKer (FTK) processor: a hardware processor for online reconstruction of particle trajectories at the ATLAS experiment at LHC. We present the architecture, design considerations, power consumption and performance measurements of the 4th generation of AMchip. We present also the design innovations toward the 5th generation and the first prototype results.

  19. Optical proximity correction for 0.15-μm-rule memory devices

    Science.gov (United States)

    Iwasaki, Haruo; Tanabe, Hiroyoshi; Inoue, Takashi; Tanaka, Yoshiyuki

    1998-12-01

    Optical proximity correction (OPC) is applied to the cell patterns of 0.15-micrometer-rule memory devices. Two kinds of memory cell patterns are studied. The first is a wire pattern which has small gaps between two wires. The small gaps can be clearly resolved by using OPC such as jogs or resizing. The second pattern is a storage node pattern which has a rectangular shape. The area of the storage node is enlarged by using OPC such as resizing, hammer heads or serifs. These OPC masks are successfully fabricated by using dry etching process.

  20. A Supramolecular Nanofiber-Based Passive Memory Device for Remembering Past Humidity.

    Science.gov (United States)

    Mogera, Umesha; Gedda, Murali; George, Subi J; Kulkarni, Giridhar U

    2017-09-20

    Memorizing the magnitude of a physical parameter such as relative humidity in a consignment may be useful for maintaining recommended conditions over a period of time. In relation to cost and energy considerations, it is important that the memorizing device works in the unpowered passive state. In this article, we report the fabrication of a humidity-responsive device that can memorize the humidity condition it had experienced while being unpowered. The device makes use of supramolecular nanofibers obtained from the self-assembly of donor-acceptor (D-A) molecules, coronene tetracarboxylate salt (CS) and dodecyl methyl viologen (DMV), respectively, from aqueous medium. The fibers, while being highly sensitive to humidity, tend to develop electrically induced disorder under constant voltage, leading to increased resistance with time. The conducting state can be regained via self-assembly by exposing the device to humidity in the absence of applied voltage, the extent of recovery depending on the magnitude of the humidity applied under no bias. This nature of the fibers has been exploited in reading the humidity memory state, which interestingly is independent of the lapsed time since the humidity exposure as well as the duration of exposure. Importantly, the device is capable of differentiating the profiles of varying humidity conditions from its memory. The device finds use in applications requiring stringent condition monitoring.

  1. Application of nanomaterials in two-terminal resistive-switching memory devices

    Directory of Open Access Journals (Sweden)

    Jianyong Ouyang

    2010-05-01

    Full Text Available Nanometer materials have been attracting strong attention due to their interesting structure and properties. Many important practical applications have been demonstrated for nanometer materials based on their unique properties. This article provides a review on the fabrication, electrical characterization, and memory application of two-terminal resistive-switching devices using nanomaterials as the active components, including metal and semiconductor nanoparticles (NPs, nanotubes, nanowires, and graphenes. There are mainly two types of device architectures for the two-terminal devices with NPs. One has a triple-layer structure with a metal film sandwiched between two organic semiconductor layers, and the other has a single polymer film blended with NPs. These devices can be electrically switched between two states with significant different resistances, i.e. the ‘ON’ and ‘OFF’ states. These render the devices important application as two-terminal non-volatile memory devices. The electrical behavior of these devices can be affected by the materials in the active layer and the electrodes. Though the mechanism for the electrical switches has been in argument, it is generally believed that the resistive switches are related to charge storage on the NPs. Resistive switches were also observed on crossbars formed by nanotubes, nanowires, and graphene ribbons. The resistive switches are due to nanoelectromechanical behavior of the materials. The Coulombic interaction of transient charges on the nanomaterials affects the configurable gap of the crossbars, which results into significant change in current through the crossbars. These nanoelectromechanical devices can be used as fast-response and high-density memory devices as well. Dr. Jianyong Ouyang received his bachelor degree from the Tsinghua University in Beijing, China, and MSc from the Institute of Chemistry, Chinese Academy of Science. He received his PhD from the Institute for Molecular

  2. Magnetic resonance flow velocity and temperature mapping of a shape memory polymer foam device

    Directory of Open Access Journals (Sweden)

    Wilson Thomas S

    2009-12-01

    Full Text Available Abstract Background Interventional medical devices based on thermally responsive shape memory polymer (SMP are under development to treat stroke victims. The goals of these catheter-delivered devices include re-establishing blood flow in occluded arteries and preventing aneurysm rupture. Because these devices alter the hemodynamics and dissipate thermal energy during the therapeutic procedure, a first step in the device development process is to investigate fluid velocity and temperature changes following device deployment. Methods A laser-heated SMP foam device was deployed in a simplified in vitro vascular model. Magnetic resonance imaging (MRI techniques were used to assess the fluid dynamics and thermal changes associated with device deployment. Results Spatial maps of the steady-state fluid velocity and temperature change inside and outside the laser-heated SMP foam device were acquired. Conclusions Though non-physiological conditions were used in this initial study, the utility of MRI in the development of a thermally-activated SMP foam device has been demonstrated.

  3. Spin orbit torques in W(O) based three terminal magnetic memory devices

    Science.gov (United States)

    Zhang, Jie; Phung, Timothy; Garg, Chirag; Rettner, Charles; Hughes, Brian. P.; Yang, See-Hun; Parkin, Stuart. S. P.

    Recently, there has been a large interest in using spin orbit torques to controllably manipulate the magnetic order parameter in several promising magnetic memory devices such as racetrack memory and spin transfer torque MRAM. The efficient operation of such devices necessitates the finding of materials which exhibit efficient conversion of charge currents to spin orbit torques. This is typically quantified by the so-called spin Hall angle. The most efficient spin orbit torque generator to date based on the use of conventional metallic materials is W(O), wherein the effective spin hall angle is found to be -0.5. Here, we explore the use of W(O) to manipulate magnetization in three terminal magnetic memory devices. We find, consistent with the large spin orbit torques, observed in W(O), that the critical current required for switching a magnetic element is significantly smaller than compared to other metallic systems such as Pt, β-W, and Ta. Lastly, we shall discuss the technologically important high speed ( ns time scale) switching dynamics in these devices and the role of complex micromagnetic states upon the switching process.

  4. Flexible All-Inorganic Perovskite CsPbBr3 Nonvolatile Memory Device.

    Science.gov (United States)

    Liu, Dongjue; Lin, Qiqi; Zang, Zhigang; Wang, Ming; Wangyang, Peihua; Tang, Xiaosheng; Zhou, Miao; Hu, Wei

    2017-02-22

    All-inorganic perovskite CsPbX 3 (X = Cl, Br, or I) is widely used in a variety of photoelectric devices such as solar cells, light-emitting diodes, lasers, and photodetectors. However, studies to understand the flexible CsPbX 3 electrical application are relatively scarce, mainly due to the limitations of the low-temperature fabricating process. In this study, all-inorganic perovskite CsPbBr 3 films were successfully fabricated at 75 °C through a two-step method. The highly crystallized films were first employed as a resistive switching layer in the Al/CsPbBr 3 /PEDOT:PSS/ITO/PET structure for flexible nonvolatile memory application. The resistive switching operations and endurance performance demonstrated the as-prepared flexible resistive random access memory devices possess reproducible and reliable memory characteristics. Electrical reliability and mechanical stability of the nonvolatile device were further tested by the robust current-voltage curves under different bending angles and consecutive flexing cycles. Moreover, a model of the formation and rupture of filaments through the CsPbBr 3 layer was proposed to explain the resistive switching effect. It is believed that this study will offer a new setting to understand and design all-inorganic perovskite materials for future stable flexible electronic devices.

  5. Nonvolatile organic write-once-read-many-times memory devices based on hexadecafluoro-copper-phthalocyanine

    Science.gov (United States)

    Wang, Lidan; Su, Zisheng; Wang, Cheng

    2012-05-01

    Nonvolatile organic write-once-read-many-times memory device was demonstrated based on hexadecafluoro-copper-phthalocyanine (F16CuPc) single layer sandwiched between indium tin oxide (ITO) anode and Al cathode. The as fabricated device remains in ON state and it can be tuned to OFF state by applying a reverse bias. The ON/OFF current ratio of the device can reach up to 2.3 × 103. Simultaneously, the device shows long-term storage stability and long retention time in air. The ON/OFF transition is attributed to the formation and destruction of the interfacial dipole layer in the ITO/F16CuPc interface, and such a mechanism is different from previously reported ones.

  6. Transparent and flexible write-once-read-many (WORM) memory device based on egg albumen

    Science.gov (United States)

    Qu, Bo; Lin, Qianru; Wan, Tao; Du, Haiwei; Chen, Nan; Lin, Xi; Chu, Dewei

    2017-08-01

    Egg albumen, as an important protein resource in nature, is an interesting dielectric material exhibiting many fascinating properties for the development of environmentally friendly electronic devices. Taking advantage of their extraordinary transparency and flexibility, this paper presents an innovative preparation approach for albumen thin film based write-once-read-many-times (WORM) memory devices in a simple, cost-effective manner. The fabricated device shows superior data retention properties including non-volatile character (over 105 s) and promising great read durability (106 times). Furthermore, our results suggested that the electric-field-induced trap-controlled space charge limited current (SCLC) conduction is responsible for the observed resistance switching effect. The present study may likely reveal another pathway towards complete see-through electrical devices.

  7. Transparent and flexible write-once-read-many (WORM) memory device based on egg albumen

    International Nuclear Information System (INIS)

    Qu, Bo; Lin, Qianru; Wan, Tao; Du, Haiwei; Chen, Nan; Lin, Xi; Chu, Dewei

    2017-01-01

    Egg albumen, as an important protein resource in nature, is an interesting dielectric material exhibiting many fascinating properties for the development of environmentally friendly electronic devices. Taking advantage of their extraordinary transparency and flexibility, this paper presents an innovative preparation approach for albumen thin film based write-once-read-many-times (WORM) memory devices in a simple, cost-effective manner. The fabricated device shows superior data retention properties including non-volatile character (over 10 5 s) and promising great read durability (10 6 times). Furthermore, our results suggested that the electric-field-induced trap-controlled space charge limited current (SCLC) conduction is responsible for the observed resistance switching effect. The present study may likely reveal another pathway towards complete see-through electrical devices. (paper)

  8. Low-energy Resistive Random Access Memory Devices with No Need for a Compliance Current

    Science.gov (United States)

    Xu, Zedong; Yu, Lina; Wu, Yong; Dong, Chang; Deng, Ning; Xu, Xiaoguang; Miao, J.; Jiang, Yong

    2015-01-01

    A novel resistive random access memory device is designed with SrTiO3/ La2/3Sr1/3MnO3 (LSMO)/MgAl2O4 (MAO)/Cu structure, in which metallic epitaxial LSMO is employed as the bottom electrode rather than traditional metal materials. In this device, the critical external compliance current is no longer necessary due to the high self-resistance of LSMO. The LMSO bottom electrode can act as a series resistor to offer a compliance current during the set process. Besides, the device also has excellent switching features which are originated in the formation of Cu filaments under external voltage. Therefore it provides the possibility of reducing power consumption and accelerating the commercialization of resistive switching devices. PMID:25982101

  9. A robust molecular platform for non-volatile memory devices with optical and magnetic responses.

    Science.gov (United States)

    Simão, Cláudia; Mas-Torrent, Marta; Crivillers, Núria; Lloveras, Vega; Artés, Juan Manuel; Gorostiza, Pau; Veciana, Jaume; Rovira, Concepció

    2011-05-01

    Bistable molecules that behave as switches in solution have long been known. Systems that can be reversibly converted between two stable states that differ in their physical properties are particularly attractive in the development of memory devices when immobilized in substrates. Here, we report a highly robust surface-confined switch based on an electroactive, persistent organic radical immobilized on indium tin oxide substrates that can be electrochemically and reversibly converted to the anion form. This molecular bistable system behaves as an extremely robust redox switch in which an electrical input is transduced into optical as well as magnetic outputs under ambient conditions. The fact that this molecular surface switch, operating at very low voltages, can be patterned and addressed locally, and also has exceptionally high long-term stability and excellent reversibility and reproducibility, makes it a very promising platform for non-volatile memory devices.

  10. Magnetic Shape Memory Alloys as smart materials for micro-positioning devices

    Directory of Open Access Journals (Sweden)

    A. Hubert

    2012-10-01

    Full Text Available In the field of microrobotics, actuators based on smart materials are predominant because of very good precision, integration capabilities and high compactness. This paper presents the main characteristics of Magnetic Shape Memory Alloys as new candidates for the design of micromechatronic devices. The thermo-magneto-mechanical energy conversion process is first presented followed by the adequate modeling procedure required to design actuators. Finally, some actuators prototypes realized at the Femto-ST institute are presented, including a push-pull bidirectional actuator. Some results on the control and performances of these devices conclude the paper.

  11. Metal-free, single-polymer device exhibits resistive memory effect

    KAUST Repository

    Bhansali, Unnat Sampatraj

    2013-12-23

    All-polymer, write-once-read-many times resistive memory devices have been fabricated on flexible substrates using a single polymer, poly(3,4- ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). Spin-cast or inkjet-printed films of solvent-modified PEDOT:PSS are used as electrodes, while the unmodified or as-is PEDOT:PSS is used as the semiconducting active layer. The all-polymer devices exhibit an irreversible but stable transition from a low resistance state (ON) to a high resistance state (OFF) at low voltages caused by an electric-field-induced morphological rearrangement of PEDOT and PSS at the electrode interface. However, in the metal-PEDOT:PSS-metal devices, we have shown a metal filament formation switching the device from an initial high resistance state (OFF) to the low resistance state (ON). The all-PEDOT:PSS memory device has low write voltages (<3 V), high ON/OFF ratio (>10 3), good retention characteristics (>10 000 s), and stability in ambient storage (>3 months). © 2013 American Chemical Society.

  12. Metal oxide resistive random access memory based synaptic devices for brain-inspired computing

    Science.gov (United States)

    Gao, Bin; Kang, Jinfeng; Zhou, Zheng; Chen, Zhe; Huang, Peng; Liu, Lifeng; Liu, Xiaoyan

    2016-04-01

    The traditional Boolean computing paradigm based on the von Neumann architecture is facing great challenges for future information technology applications such as big data, the Internet of Things (IoT), and wearable devices, due to the limited processing capability issues such as binary data storage and computing, non-parallel data processing, and the buses requirement between memory units and logic units. The brain-inspired neuromorphic computing paradigm is believed to be one of the promising solutions for realizing more complex functions with a lower cost. To perform such brain-inspired computing with a low cost and low power consumption, novel devices for use as electronic synapses are needed. Metal oxide resistive random access memory (ReRAM) devices have emerged as the leading candidate for electronic synapses. This paper comprehensively addresses the recent work on the design and optimization of metal oxide ReRAM-based synaptic devices. A performance enhancement methodology and optimized operation scheme to achieve analog resistive switching and low-energy training behavior are provided. A three-dimensional vertical synapse network architecture is proposed for high-density integration and low-cost fabrication. The impacts of the ReRAM synaptic device features on the performances of neuromorphic systems are also discussed on the basis of a constructed neuromorphic visual system with a pattern recognition function. Possible solutions to achieve the high recognition accuracy and efficiency of neuromorphic systems are presented.

  13. Effect of vacuum annealing on evaporated pentacene thin films for memory device applications

    International Nuclear Information System (INIS)

    Gayathri, A.G.; Joseph, C.M.

    2016-01-01

    Graphical abstract: Switching of ITO/pentacene/Al thin films for different annealing temperatures. - Highlights: • Memory device performance in pentacene improved considerably with annealing. • ON/OFF ratio of the pentacene device increases due to annealing. • Threshold voltage reduces from 2.55 V to 1.35 V due to annealing. • Structure of pentacene thin films is also dependent on annealing temperature. - Abstract: Thin films of pentacene were deposited thermally onto glass substrates and annealed at 323 K, 373 K, 423 K, 473 K and 523 K in high vacuum. Effect of annealing on the morphological and structural properties of these films was studied. X-ray diffraction patterns confirmed the crystalline nature of the films. Electrical studies for the use as write once read many (WORM) memory devices were done for the vacuum deposited pentacene thin films on indium tin oxide coated glass. Due to annealing, a sharp increase in the ON/OFF ratio of current and a decrease in threshold voltage were observed at around 373 K. This device showed a stable switching with an ON/OFF current ratio as high as 10 9 and a switching threshold voltage of 1.35 V. The performance of the device degraded above 423 K due to the changes in the crystallinity of the film.

  14. Interfacial behavior of resistive switching in ITO–PVK–Al WORM memory devices

    International Nuclear Information System (INIS)

    Whitcher, T J; Woon, K L; Wong, W S; Chanlek, N; Nakajima, H; Saisopa, T; Songsiriritthigul, P

    2016-01-01

    Understanding the mechanism of resistive switching in a memory device is fundamental in order to improve device performance. The mechanism of current switching in a basic organic write-once read-many (WORM) memory device is investigated by determining the energy level alignments of indium tin oxide (ITO), poly(9-vinylcarbazole) (PVK) and aluminum (Al) using x-ray and ultraviolet photoelectron spectroscopy, current–voltage characterization and Auger depth profiling. The current switching mechanism was determined to be controlled by the interface between the ITO and the PVK. The electric field applied across the device causes the ITO from the uneven surface of the anode to form metallic filaments through the PVK, causing a shorting effect within the device leading to increased conduction. This was found to be independent of the PVK thickness, although the switch-on voltage was non-linearly dependent on the thickness. The formation of these filaments also caused the destruction of the interfacial dipole at the PVK–Al interface. (paper)

  15. Interfacial behavior of resistive switching in ITO-PVK-Al WORM memory devices

    Science.gov (United States)

    Whitcher, T. J.; Woon, K. L.; Wong, W. S.; Chanlek, N.; Nakajima, H.; Saisopa, T.; Songsiriritthigul, P.

    2016-02-01

    Understanding the mechanism of resistive switching in a memory device is fundamental in order to improve device performance. The mechanism of current switching in a basic organic write-once read-many (WORM) memory device is investigated by determining the energy level alignments of indium tin oxide (ITO), poly(9-vinylcarbazole) (PVK) and aluminum (Al) using x-ray and ultraviolet photoelectron spectroscopy, current-voltage characterization and Auger depth profiling. The current switching mechanism was determined to be controlled by the interface between the ITO and the PVK. The electric field applied across the device causes the ITO from the uneven surface of the anode to form metallic filaments through the PVK, causing a shorting effect within the device leading to increased conduction. This was found to be independent of the PVK thickness, although the switch-on voltage was non-linearly dependent on the thickness. The formation of these filaments also caused the destruction of the interfacial dipole at the PVK-Al interface.

  16. An optically transparent and flexible memory with embedded gold nanoparticles in a polymethylsilsesquioxane dielectric

    Energy Technology Data Exchange (ETDEWEB)

    Ooi, P.C. [Mechanical Engineering, The University of Auckland (New Zealand); Aw, K.C., E-mail: k.aw@auckland.ac.nz [Mechanical Engineering, The University of Auckland (New Zealand); Gao, W. [Chemical and Materials Engineering, The University of Auckland (New Zealand); Razak, K.A. [School of Materials and Mineral Resources Engineering, Universiti Sains (Malaysia); NanoBiotechnology Research and Innovation, INFORMM, Universiti Sains (Malaysia)

    2013-10-01

    In this work, we demonstrated a simple fabrication route towards an optically transparent and flexible memory device. The device is simple and consists of a metal/insulator/semiconductor structure; namely MIS. The preliminary MIS study with gold nanoparticles embedded between the polymethylsilsesquioxane layers was fabricated on p-Si substrate and the capacitance versus voltage measurements confirmed the charge trapped capability of the fabricated MIS memory device. Subsequently, an optically transparent and flexible MIS memory device made from indium–tin-oxide coated polyethylene terephthalate substrate and pentacene was used to replace the opaque p-Si substrate as the active layer. Current versus voltage (I–V) plot of the transparent and flexible device shows the presence of hysteresis. In an I–V plot, three distinct regions have been identified and the transport mechanisms are explained. The fabricated optically transparent and mechanically flexible MIS memory device can be programmed and erased multiple times, similar to a flash memory. Mechanical characterization to determine the robustness of the flexible memory device was also conducted but failed to establish any relationship in this preliminary work as the effect was random. Hence, more work is needed to understand the reliability of this device, especially when they are subjected to mechanical stress. - Highlights: ► An optically transparent and mechanically flexible memory is presented. ► Electrical characteristics show reprogrammable memory similar to flash memory. ► Transport mechanisms are proposed and explained. ► Mechanical bending tests are conducted.

  17. An optically transparent and flexible memory with embedded gold nanoparticles in a polymethylsilsesquioxane dielectric

    International Nuclear Information System (INIS)

    Ooi, P.C.; Aw, K.C.; Gao, W.; Razak, K.A.

    2013-01-01

    In this work, we demonstrated a simple fabrication route towards an optically transparent and flexible memory device. The device is simple and consists of a metal/insulator/semiconductor structure; namely MIS. The preliminary MIS study with gold nanoparticles embedded between the polymethylsilsesquioxane layers was fabricated on p-Si substrate and the capacitance versus voltage measurements confirmed the charge trapped capability of the fabricated MIS memory device. Subsequently, an optically transparent and flexible MIS memory device made from indium–tin-oxide coated polyethylene terephthalate substrate and pentacene was used to replace the opaque p-Si substrate as the active layer. Current versus voltage (I–V) plot of the transparent and flexible device shows the presence of hysteresis. In an I–V plot, three distinct regions have been identified and the transport mechanisms are explained. The fabricated optically transparent and mechanically flexible MIS memory device can be programmed and erased multiple times, similar to a flash memory. Mechanical characterization to determine the robustness of the flexible memory device was also conducted but failed to establish any relationship in this preliminary work as the effect was random. Hence, more work is needed to understand the reliability of this device, especially when they are subjected to mechanical stress. - Highlights: ► An optically transparent and mechanically flexible memory is presented. ► Electrical characteristics show reprogrammable memory similar to flash memory. ► Transport mechanisms are proposed and explained. ► Mechanical bending tests are conducted

  18. Flash mobile

    CERN Document Server

    David, Matthew

    2013-01-01

    Get your app online and ready for purchase. Building your app for deployment using iTunes ConnectBuilding your app for deployment on the Android MarketBuilding for iPad devicesBuilding for Android tablets and Google TVAdding advertising to your appsTracking your app's successMarketing your app

  19. Germanium nanoparticles grown at different deposition times for memory device applications

    International Nuclear Information System (INIS)

    Mederos, M.; Mestanza, S.N.M.; Lang, R.; Doi, I.; Diniz, J.A.

    2016-01-01

    In the present work, circular Metal-Oxide-Semiconductor capacitors with 200 μm of diameter and germanium (Ge) nanoparticles (NPs) embedded in the gate oxide are studied for memory applications. Optimal process parameters are investigated for Ge NPs growing by low pressure chemical vapor deposition at different deposition times. Photoluminescence measurements showed room-temperature size-dependent green-red region bands attributed to quantum confinement effects present in the NPs. High-frequency capacitance versus voltage measurements demonstrated the memory effects on the MOS structures due to the presence of Ge NPs in the gate oxide acting as discrete floating gates. Current versus voltage measurements confirmed the Fowler-Nordheim tunneling as the programming mechanism of the devices. - Highlights: • Ge nanoparticles with high density and uniforms sizes were obtained by LPCVD. • Room-temperature size-dependent bands of photoluminescence were observed. • MOS capacitors with Ge nanoparticles embedded in the oxide were fabricated. • Ge nanoparticles are the main responsible for the memory properties in the devices. • Fowler-Nordheim tunneling is the conduction mechanism observed on the devices.

  20. Germanium nanoparticles grown at different deposition times for memory device applications

    Energy Technology Data Exchange (ETDEWEB)

    Mederos, M., E-mail: melissa.mederos@gmail.com [Center for Semiconductor Components and Nanotechnology (CCSNano), University of Campinas (Unicamp), Rua João Pandia Calógeras 90, Campinas, CEP: 13083-870, São Paulo (Brazil); Mestanza, S.N.M. [Federal University of ABC (UFABC), Rua Santa Adélia 166, Bangu, Santo André, CEP: 09210-170, São Paulo (Brazil); Lang, R. [Institute of Science and Technology, Federal University of São Paulo (UNIFESP), Rua Talim, 330, São José dos Campos, CEP: 12231-280, São Paulo (Brazil); Doi, I.; Diniz, J.A. [Center for Semiconductor Components and Nanotechnology (CCSNano), University of Campinas (Unicamp), Rua João Pandia Calógeras 90, Campinas, CEP: 13083-870, São Paulo (Brazil); School of Electrical and Computer Engineering, University of Campinas (Unicamp), Av. Albert Einstein 400, Campinas, CEP: 13083-852, São Paulo (Brazil)

    2016-07-29

    In the present work, circular Metal-Oxide-Semiconductor capacitors with 200 μm of diameter and germanium (Ge) nanoparticles (NPs) embedded in the gate oxide are studied for memory applications. Optimal process parameters are investigated for Ge NPs growing by low pressure chemical vapor deposition at different deposition times. Photoluminescence measurements showed room-temperature size-dependent green-red region bands attributed to quantum confinement effects present in the NPs. High-frequency capacitance versus voltage measurements demonstrated the memory effects on the MOS structures due to the presence of Ge NPs in the gate oxide acting as discrete floating gates. Current versus voltage measurements confirmed the Fowler-Nordheim tunneling as the programming mechanism of the devices. - Highlights: • Ge nanoparticles with high density and uniforms sizes were obtained by LPCVD. • Room-temperature size-dependent bands of photoluminescence were observed. • MOS capacitors with Ge nanoparticles embedded in the oxide were fabricated. • Ge nanoparticles are the main responsible for the memory properties in the devices. • Fowler-Nordheim tunneling is the conduction mechanism observed on the devices.

  1. Method and device for efficiently updating data in electronic devices

    OpenAIRE

    Sánchez Espeso, Pablo Pedro; Díaz Suárez, Álvaro

    2014-01-01

    ABSTRACT: The invention relates to a method and a device for efficiently updating data in electronic devices, solving problems presented by existing techniques in a simple manner. The invention allows the device to be updated rapidly, with low energy consumption, and minimising the number of times the non-volatile memory unit (for example, flash) is erased, at a profitable cost. RESUMEN: Método y dispositivo para la actualización eficiente de datos en dispositivos electrónicos que resuelve...

  2. Systematic Development Strategy for Smart Devices Based on Shape-Memory Polymers

    Directory of Open Access Journals (Sweden)

    Andrés Díaz Lantada

    2017-10-01

    Full Text Available Shape-memory polymers are outstanding “smart” materials, which can perform important geometrical changes, when activated by several types of external stimuli, and which can be applied to several emerging engineering fields, from aerospace applications, to the development of biomedical devices. The fact that several shape-memory polymers can be structured in an additive way is an especially noteworthy advantage, as the development of advanced actuators with complex geometries for improved performance can be achieved, if adequate design and manufacturing considerations are taken into consideration. Present study presents a review of challenges and good practices, leading to a straightforward methodology (or integration of strategies, for the development of “smart” actuators based on shape-memory polymers. The combination of computer-aided design, computer-aided engineering and additive manufacturing technologies is analyzed and applied to the complete development of interesting shape-memory polymer-based actuators. Aspects such as geometrical design and optimization, development of the activation system, selection of the adequate materials and related manufacturing technologies, training of the shape-memory effect, final integration and testing are considered, as key processes of the methodology. Current trends, including the use of low-cost 3D and 4D printing, and main challenges, including process eco-efficiency and biocompatibility, are also discussed and their impact on the proposed methodology is considered.

  3. High Performance Transparent Transistor Memory Devices Using Nano-Floating Gate of Polymer/ZnO Nanocomposites

    Science.gov (United States)

    Shih, Chien-Chung; Lee, Wen-Ya; Chiu, Yu-Cheng; Hsu, Han-Wen; Chang, Hsuan-Chun; Liu, Cheng-Liang; Chen, Wen-Chang

    2016-01-01

    Nano-floating gate memory devices (NFGM) using metal nanoparticles (NPs) covered with an insulating polymer have been considered as a promising electronic device for the next-generation nonvolatile organic memory applications NPs. However, the transparency of the device with metal NPs is restricted to 60~70% due to the light absorption in the visible region caused by the surface plasmon resonance effects of metal NPs. To address this issue, we demonstrate a novel NFGM using the blends of hole-trapping poly (9-(4-vinylphenyl) carbazole) (PVPK) and electron-trapping ZnO NPs as the charge storage element. The memory devices exhibited a remarkably programmable memory window up to 60 V during the program/erase operations, which was attributed to the trapping/detrapping of charge carriers in ZnO NPs/PVPK composite. Furthermore, the devices showed the long-term retention time (>105 s) and WRER test (>200 cycles), indicating excellent electrical reliability and stability. Additionally, the fabricated transistor memory devices exhibited a relatively high transparency of 90% at the wavelength of 500 nm based on the spray-coated PEDOT:PSS as electrode, suggesting high potential for transparent organic electronic memory devices. PMID:26831222

  4. MIEC (mixed-ionic-electronic-conduction)-based access devices for non-volatile crossbar memory arrays

    International Nuclear Information System (INIS)

    Shenoy, Rohit S; Burr, Geoffrey W; Virwani, Kumar; Jackson, Bryan; Padilla, Alvaro; Narayanan, Pritish; Rettner, Charles T; Shelby, Robert M; Bethune, Donald S; Rice, Philip M; Topuria, Teya; Kellock, Andrew J; Kurdi, Bülent; Raman, Karthik V; BrightSky, Matthew; Joseph, Eric; Gopalakrishnan, Kailash

    2014-01-01

    Several attractive applications call for the organization of memristive devices (or other resistive non-volatile memory (NVM)) into large, densely-packed crossbar arrays. While resistive-NVM devices frequently possess some degree of inherent nonlinearity (typically 3–30× contrast), the operation of large (> 1000×1000 device) arrays at low power tends to require quite large (> 1e7) ON-to-OFF ratios (between the currents passed at high and at low voltages). One path to such large nonlinearities is the inclusion of a distinct access device (AD) together with each of the state-bearing resistive-NVM elements. While such an AD need not store data, its list of requirements is almost as challenging as the specifications demanded of the memory device. Several candidate ADs have been proposed, but obtaining high performance without requiring single-crystal silicon and/or the high processing temperatures of the front-end-of-the-line—which would eliminate any opportunity for 3D stacking—has been difficult. We review our work at IBM Research—Almaden on high-performance ADs based on Cu-containing mixed-ionic-electronic conduction (MIEC) materials [1–7]. These devices require only the low processing temperatures of the back-end-of-the-line, making them highly suitable for implementing multi-layer cross-bar arrays. MIEC-based ADs offer large ON/OFF ratios (>1e7), a significant voltage margin V m (over which current <10 nA), and ultra-low leakage (< 10 pA), while also offering the high current densities needed for phase-change memory and the fully bipolar operation needed for high-performance RRAM. Scalability to critical lateral dimensions < 30 nm and thicknesses < 15 nm, tight distributions and 100% yield in large (512 kBit) arrays, long-term stability of the ultra-low leakage states, and sub-50 ns turn-ON times have all been demonstrated. Numerical modeling of these MIEC-based ADs shows that their operation depends on Cu + mediated hole conduction. Circuit

  5. MIEC (mixed-ionic-electronic-conduction)-based access devices for non-volatile crossbar memory arrays

    Science.gov (United States)

    Shenoy, Rohit S.; Burr, Geoffrey W.; Virwani, Kumar; Jackson, Bryan; Padilla, Alvaro; Narayanan, Pritish; Rettner, Charles T.; Shelby, Robert M.; Bethune, Donald S.; Raman, Karthik V.; BrightSky, Matthew; Joseph, Eric; Rice, Philip M.; Topuria, Teya; Kellock, Andrew J.; Kurdi, Bülent; Gopalakrishnan, Kailash

    2014-10-01

    Several attractive applications call for the organization of memristive devices (or other resistive non-volatile memory (NVM)) into large, densely-packed crossbar arrays. While resistive-NVM devices frequently possess some degree of inherent nonlinearity (typically 3-30× contrast), the operation of large (\\gt 1000×1000 device) arrays at low power tends to require quite large (\\gt 1e7) ON-to-OFF ratios (between the currents passed at high and at low voltages). One path to such large nonlinearities is the inclusion of a distinct access device (AD) together with each of the state-bearing resistive-NVM elements. While such an AD need not store data, its list of requirements is almost as challenging as the specifications demanded of the memory device. Several candidate ADs have been proposed, but obtaining high performance without requiring single-crystal silicon and/or the high processing temperatures of the front-end-of-the-line—which would eliminate any opportunity for 3D stacking—has been difficult. We review our work at IBM Research—Almaden on high-performance ADs based on Cu-containing mixed-ionic-electronic conduction (MIEC) materials [1-7]. These devices require only the low processing temperatures of the back-end-of-the-line, making them highly suitable for implementing multi-layer cross-bar arrays. MIEC-based ADs offer large ON/OFF ratios (\\gt 1e7), a significant voltage margin {{V}m} (over which current \\lt 10 nA), and ultra-low leakage (\\lt 10 pA), while also offering the high current densities needed for phase-change memory and the fully bipolar operation needed for high-performance RRAM. Scalability to critical lateral dimensions \\lt 30 nm and thicknesses \\lt 15 nm, tight distributions and 100% yield in large (512 kBit) arrays, long-term stability of the ultra-low leakage states, and sub-50 ns turn-ON times have all been demonstrated. Numerical modeling of these MIEC-based ADs shows that their operation depends on C{{u}+} mediated hole

  6. Exploring Spin-transfer-torque devices and memristors for logic and memory applications

    Science.gov (United States)

    Pajouhi, Zoha

    As scaling CMOS devices is approaching its physical limits, researchers have begun exploring newer devices and architectures to replace CMOS. Due to their non-volatility and high density, Spin Transfer Torque (STT) devices are among the most prominent candidates for logic and memory applications. In this research, we first considered a new logic style called All Spin Logic (ASL). Despite its advantages, ASL consumes a large amount of static power; thus, several optimizations can be performed to address this issue. We developed a systematic methodology to perform the optimizations to ensure stable operation of ASL. Second, we investigated reliable design of STT-MRAM bit-cells and addressed the conflicting read and write requirements, which results in overdesign of the bit-cells. Further, a Device/Circuit/Architecture co-design framework was developed to optimize the STT-MRAM devices by exploring the design space through jointly considering yield enhancement techniques at different levels of abstraction. Recent advancements in the development of memristive devices have opened new opportunities for hardware implementation of non-Boolean computing. To this end, the suitability of memristive devices for swarm intelligence algorithms has enabled researchers to solve a maze in hardware. In this research, we utilized swarm intelligence of memristive networks to perform image edge detection. First, we proposed a hardware-friendly algorithm for image edge detection based on ant colony. Next, we designed the image edge detection algorithm using memristive networks.

  7. Charging effect in Au nanoparticle memory device with biomolecule binding mechanism.

    Science.gov (United States)

    Jung, Sung Mok; Kim, Hyung-Jun; Kim, Bong-Jin; Yoon, Tae-Sik; Kim, Yong-Sang; Lee, Hyun Ho

    2011-07-01

    Organic memory device having gold nanoparticle (Au NPs) has been introduced in the structure of metal-pentacene-insulator-silicon (MPIS) capacitor device, where the Au NPs layer was formed by a new bonding method. Biomolecule binding mechanism between streptavidin and biotin was used as a strong binding method for the formation of monolayered Au NPs on polymeric dielectric of poly vinyl alcohol (PVA). The self-assembled Au NPs was functioned to show storages of charge in the MPIS device. The binding by streptavidin and biotin was confirmed by AFM and UV-VIS. The UV-VIS absorption of the Au NPs was varied at 515 nm and 525 nm depending on the coating of streptavidin. The AFM image showed no formation of multi-stacked layers of the streptavidin-capped Au NPs on biotin-NHS layer. Capacitance-voltage (C-V) performance of the memory device was measured to investigate the charging effect from Au NPs. In addition, charge retention by the Au NPs storage was tested to show 10,000 s in the C-V curve.

  8. Simple flash evaporator for making thin films of compounds

    Energy Technology Data Exchange (ETDEWEB)

    Hemanadhan, M.; Bapanayya, Ch.; Agarwal, S. C. [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India)

    2010-07-15

    A simple and compact arrangement for flash evaporation is described. It uses a cell phone vibrator for powder dispensing that can be incorporated into a vacuum deposition chamber without any major alterations. The performance of the flash evaporation system is checked by making thin films of the optical memory chalcogenide glass Ge{sub 2}Sb{sub 2}Te{sub 5} (GST). Energy dispersive x-ray analysis shows that the flash evaporation preserves the stoichiometry in thin films.

  9. DIRCM FLASH Flight Tests

    National Research Council Canada - National Science Library

    Molocher, Bernhard; Kaltenecker, Anton; Thum-Jaeger, Andrea; Regensburger, Martin; Formery, Martin

    2005-01-01

    .... FLASH operation is as follows: After handover following an alarm from the missile warning system FLASH enters autonomous passive tracking mode for tracking a missiles and sending a laser beam onto the missile...

  10. Characterization of charge injection and trapping in scaled SONOS/MONOS memory devices

    Science.gov (United States)

    Chao, Chen-Chung; White, Marvin H.

    1987-03-01

    In this paper we investigate scaled SONOS/MONOS (polysilicon-oxide-nitride-oxide-semiconductor)/(metal-oxide-nitride-oxide-semiconductor) memory devices, and the characterization of storage traps in the nitride. The amphoteric and closely-compensating trap models, which describe the positive and negative charging of the nitride "memory" layer, have been compared. "Scaled" complementary SONOS and MONOS nonvolatile memory transistors with the nitride thickness ranging from 85 to 185 A have been designed and fabricated. The linear voltage-ramp method, which measures the flatband voltage shift and separates the charges at the injecting boundary during the WRITE/ERASE operations, has been employed to study non-steady state trapping in the nitride of "scaled" complementary SONOS/MONOS devices for low voltage E 2PROM's (electrically erasable and programmable read only memories). We have demonstrated a differential, saturated flatband voltage shift of 6.5 V with a ±8 V programming voltage for scaled-down devices with dimensions of 20 A for the tunnel oxide, 85 A for the nitride, and 51 A for the blocking oxide. Charge injection and trapping in scaled multi-dielectric structures have been modelled with an amphoteric trap concept. The trap density NT0 , ≈ 10 19 cm -3, effective capture cross section of electrons and holes, ̂gs n+, ̂gs p- ≈10 -13cm2, and effective capture cross section of neutral charge states, ̂gs n0, ̂gs p0 ≈ 10 -14cm2, have been determined with an amphoteric trap model.

  11. Physical principles and current status of emerging non-volatile solid state memories

    Science.gov (United States)

    Wang, L.; Yang, C.-H.; Wen, J.

    2015-07-01

    Today the influence of non-volatile solid-state memories on persons' lives has become more prominent because of their non-volatility, low data latency, and high robustness. As a pioneering technology that is representative of non-volatile solidstate memories, flash memory has recently seen widespread application in many areas ranging from electronic appliances, such as cell phones and digital cameras, to external storage devices such as universal serial bus (USB) memory. Moreover, owing to its large storage capacity, it is expected that in the near future, flash memory will replace hard-disk drives as a dominant technology in the mass storage market, especially because of recently emerging solid-state drives. However, the rapid growth of the global digital data has led to the need for flash memories to have larger storage capacity, thus requiring a further downscaling of the cell size. Such a miniaturization is expected to be extremely difficult because of the well-known scaling limit of flash memories. It is therefore necessary to either explore innovative technologies that can extend the areal density of flash memories beyond the scaling limits, or to vigorously develop alternative non-volatile solid-state memories including ferroelectric random-access memory, magnetoresistive random-access memory, phase-change random-access memory, and resistive random-access memory. In this paper, we review the physical principles of flash memories and their technical challenges that affect our ability to enhance the storage capacity. We then present a detailed discussion of novel technologies that can extend the storage density of flash memories beyond the commonly accepted limits. In each case, we subsequently discuss the physical principles of these new types of non-volatile solid-state memories as well as their respective merits and weakness when utilized for data storage applications. Finally, we predict the future prospects for the aforementioned solid-state memories for

  12. Analog memory and spike-timing-dependent plasticity characteristics of a nanoscale titanium oxide bilayer resistive switching device

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Kyungah; Park, Sangsu; Lee, Kwanghee; Lee, Byounghun; Hwang, Hyunsang [Department of Nanobio Materials and Electronics, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of); Kim, Insung; Jung, Seungjae; Jo, Minseok; Park, Jubong; Shin, Jungho; Biju, Kuyyadi P; Kong, Jaemin, E-mail: kyseo@gist.ac.kr, E-mail: hwanghs@gist.ac.kr [School of Material Science and Engineering, Gwangju Institute of Science and Technology, Gwangju 500-712 (Korea, Republic of)

    2011-06-24

    We demonstrated analog memory, synaptic plasticity, and a spike-timing-dependent plasticity (STDP) function with a nanoscale titanium oxide bilayer resistive switching device with a simple fabrication process and good yield uniformity. We confirmed the multilevel conductance and analog memory characteristics as well as the uniformity and separated states for the accuracy of conductance change. Finally, STDP and a biological triple model were analyzed to demonstrate the potential of titanium oxide bilayer resistive switching device as synapses in neuromorphic devices. By developing a simple resistive switching device that can emulate a synaptic function, the unique characteristics of synapses in the brain, e.g. combined memory and computing in one synapse and adaptation to the outside environment, were successfully demonstrated in a solid state device.

  13. Synthesis of Gold Nanoparticles Capped with Quaterthiophene for Transistor and Resistor Memory Devices

    Directory of Open Access Journals (Sweden)

    Mai Ha Hoang

    2016-01-01

    Full Text Available Recently, the fabrication of nonvolatile memory devices based on gold nanoparticles has been intensively investigated. In this work, we report on the design and synthesis of new semiconducting quaterthiophene incorporating hexyl thiol group (4TT. Gold nanoparticles capped with 4TT (4TTG were prepared in a two-phase liquid-liquid system. These nanoparticles have diameters in the range 2–6 nm and are well dispersed in the poly(3-hexylthiophene (P3HT host matrix. The intermolecular interaction between 4TT and P3HT could enhance the charge-transport between gold nanoparticles and P3HT. Transfer curve of transistor memory device made of 4TTG/P3HT hybrid film exhibited significant current hysteresis, probably arising from the energy level barrier at 4TTG/P3HT interface. Additionally, the polymer memory resistor structure with an active layer consisting of 4TTG and P3HT displayed a remarkable electrical bistable behavior.

  14. Resistive switching effect of N-doped MoS2-PVP nanocomposites films for nonvolatile memory devices

    Science.gov (United States)

    Wu, Zijin; Wang, Tongtong; Sun, Changqi; Liu, Peitao; Xia, Baorui; Zhang, Jingyan; Liu, Yonggang; Gao, Daqiang

    2017-12-01

    Resistive memory technology is very promising in the field of semiconductor memory devices. According to Liu et al, MoS2-PVP nanocomposite can be used as an active layer material for resistive memory devices due to its bipolar resistive switching behavior. Recent studies have also indicated that the doping of N element can reduce the band gap of MoS2 nanosheets, which is conducive to improving the conductivity of the material. Therefore, in this paper, we prepared N-doped MoS2 nanosheets and then fabricated N-doped MoS2-PVP nanocomposite films by spin coating. Finally, the resistive memory [C. Tan et al., Chem. Soc. Rev. 44, 2615 (2015)], device with ITO/N-doped MoS2-PVP/Pt structure was fabricated. Study on the I-V characteristics shows that the device has excellent resistance switching effect. It is worth mentioning that our device possesses a threshold voltage of 0.75 V, which is much better than 3.5 V reported previously for the undoped counterparts. The above research shows that N-doped MoS2-PVP nanocomposite films can be used as the active layer of resistive switching memory devices, and will make the devices have better performance.

  15. Current Status of Nonvolatile Semiconductor Memory Technology

    Science.gov (United States)

    Fujisaki, Yoshihisa

    2010-10-01

    In this report, an overview of the current status of nonvolatile semiconductor memory technology is presented. We are reaching the integration limit of flash memories, and many new types of memories to replace conventional flash memories have been proposed. Unlike flash memories, new nonvolatile memories do not require electric charge storing. The possibility of phase-change random access memory (PRAM) or resistive-change RAM (ReRAM) replacing ultrahigh-density NAND flash memories has been discussed; however, there are many issues to overcome, making the replacement difficult. Nonetheless, ferroelectric RAMs (FeRAMs) and MRAMs are gradually penetrating into fields where the shortcomings of flash memories, such as high operating voltage, slow rewriting speed, and limited number of rewrites, make their use inconvenient. For the successful application of new nonvolatile semiconductor memories, they must be practically utilized in new fields in which flash memories are not applicable, and the technology for them must be developed.

  16. Anisotropic sensor and memory device with a ferromagnetic tunnel barrier as the only magnetic element.

    Science.gov (United States)

    Lόpez-Mir, L; Frontera, C; Aramberri, H; Bouzehouane, K; Cisneros-Fernández, J; Bozzo, B; Balcells, L; Martínez, B

    2018-01-16

    Multiple spin functionalities are probed on Pt/La 2 Co 0.8 Mn 1.2 O 6 /Nb:SrTiO 3 , a device composed by a ferromagnetic insulating barrier sandwiched between non-magnetic electrodes. Uniquely, La 2 Co 0.8 Mn 1.2 O 6 thin films present strong perpendicular magnetic anisotropy of magnetocrystalline origin, property of major interest for spintronics. The junction has an estimated spin-filtering efficiency of 99.7% and tunneling anisotropic magnetoresistance (TAMR) values up to 30% at low temperatures. This remarkable angular dependence of the magnetoresistance is associated with the magnetic anisotropy whose origin lies in the large spin-orbit interaction of Co 2+ which is additionally tuned by the strain of the crystal lattice. Furthermore, we found that the junction can operate as an electrically readable magnetic memory device. The findings of this work demonstrate that a single ferromagnetic insulating barrier with strong magnetocrystalline anisotropy is sufficient for realizing sensor and memory functionalities in a tunneling device based on TAMR.

  17. Comparison of single event upset rates for microelectronic memory devices during interplanetary solar particle events

    Science.gov (United States)

    Mckerracher, P. L.; Kinnison, J. D.; Maurer, R. H.

    1993-01-01

    Variability in the methods and models used for single event upset calculations in microelectronic memory devices can lead to a range of possible upset rates. Using heavy ion and proton data for selected DRAM and SRAM memories, we have calculated an array of upset rates in order to compare the Adams worst case interplanetary solar flare model to a model proposed by scientists at the Jet Propulsion Laboratory. In addition, methods of upset rate calculation are compared: the Cosmic Ray Effects on Microelectronics CREME code and a Monte Carlo algorithm developed at the Applied Physics Laboratory. The results show that use of a more realistic, although still conservative, model of the space environment can have significant cost saving benefits.

  18. Non-volatile memory for checkpoint storage

    Science.gov (United States)

    Blumrich, Matthias A.; Chen, Dong; Cipolla, Thomas M.; Coteus, Paul W.; Gara, Alan; Heidelberger, Philip; Jeanson, Mark J.; Kopcsay, Gerard V.; Ohmacht, Martin; Takken, Todd E.

    2014-07-22

    A system, method and computer program product for supporting system initiated checkpoints in high performance parallel computing systems and storing of checkpoint data to a non-volatile memory storage device. The system and method generates selective control signals to perform checkpointing of system related data in presence of messaging activity associated with a user application running at the node. The checkpointing is initiated by the system such that checkpoint data of a plurality of network nodes may be obtained even in the presence of user applications running on highly parallel computers that include ongoing user messaging activity. In one embodiment, the non-volatile memory is a pluggable flash memory card.

  19. Defect engineering: reduction effect of hydrogen atom impurities in HfO2-based resistive-switching memory devices

    International Nuclear Information System (INIS)

    Kim, Seonghyun; Park, Jubong; Jung, Seungjae; Lee, Wootae; Shin, Jungho; Hwang, Hyunsang; Lee, Daeseok; Woo, Jiyong; Choi, Godeuni

    2012-01-01

    In this study, we propose a new and effective methodology for improving the resistive-switching performance of memory devices by high-pressure hydrogen annealing under ambient conditions. The reduction effect results in the uniform creation of oxygen vacancies that in turn enable forming-free operation and afford uniform switching characteristics. In addition, H + and mobile hydroxyl (OH − ) ions are generated, and these induce fast switching operation due to the higher mobility compared to oxygen ions. Defect engineering, specifically, the introduction of hydrogen atom impurities, improves the device performance for metal–oxide-based resistive-switching random access memory devices. (paper)

  20. Role of potential fluctuations in phase-change GST memory devices

    Energy Technology Data Exchange (ETDEWEB)

    Agarwal, Satish C. [Department of Physics, Indian Institute of Technology, Kanpur 208016 (India)

    2012-10-15

    The long range potential fluctuations (LRPFs) arising from the defects and heterogeneities in disordered semiconductors are important for understanding their atomic and electronic properties. Here, they are measured in Ge{sub X}Sb{sub Y}Te{sub 1-X-Y} (GST) chalcogenide glasses used in rewritable phase change memory (PCM) devices. It is found that the most commonly used composition Ge{sub 2}Sb{sub 2}Te{sub 5} has the smallest LRPF amongst its nearby compositions. This finding may be useful in the search for better PCM materials. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Charge retention of scaled SONOS nonvolatile memory devices at elevated temperatures

    Science.gov (United States)

    Yang, Yang (Larr); White, Marvin H.

    2000-06-01

    The charge retention characteristics in scaled SONOS nonvolatile memory devices with an effective gate oxide thickness of 94 Å and a tunnel oxide of 15 Å are investigated in a temperature range from room temperature to 175°C. Electron charge decay rate is sensitive to the temperature, whereas hole charge decay rate remains essentially constant. Based on experimental observations and an amphoteric trap model for nitride traps, an analytical model for charge retention of the excess electron state is developed. Using this thermal activated electron retention model, the trap distribution in energy within the nitride film is extracted.

  2. Self-formed conductive nanofilaments in (Bi, Mn)Ox for ultralow-power memory devices

    KAUST Repository

    Kang, Chen Fang

    2015-04-01

    Resistive random access memory (RRAM) is one of the most promising candidates as a next generation nonvolatile memory (NVM), owing to its superior scalability, low power consumption and high speed. From the materials science point of view, to explore optimal RRAM materials is still essential for practical application. In this work, a new material (Bi, Mn)Ox (BMO) is investigated and several key performance characteristics of Pt/BMO/Pt structured device, including switching performance, retention and endurance, are examined in details. Furthermore, it has been confirmed by high-resolution transmission electron microscopy that the underlying switching mechanism is attributed to formation and disruption of metallic conducting nanofilaments (CNFs). More importantly, the power dissipation for each CNF is as low as 3.8/20fJ for set/reset process, and a realization of cross-bar structure memory cell is demonstrated to prove the downscaling ability of proposed RRAM. These distinctive properties have important implications for understanding switching mechanisms and implementing ultralow power-dissipation RRAM based on BMO. •Self-formed conductive nanofilaments in BMO show ultralow-power memory feature.•The feature of 10nm in diameter and an average 20-30nm spacing of CNFs suggests the compatibility with the current CMOS technologies.•Power dissipation for each CNF is as low as 3.8/20fJ for set/reset process•A realization of cross-bar structure memory cell is demonstrated to prove the downscaling ability of proposed RRAM. © 2015 Elsevier Ltd.

  3. A light incident angle switchable ZnO nanorod memristor: reversible switching behavior between two non-volatile memory devices.

    Science.gov (United States)

    Park, Jinjoo; Lee, Seunghyup; Lee, Junghan; Yong, Kijung

    2013-11-26

    A light incident angle selectivity of a memory device is demonstrated. As a model system, the ZnO resistive switching device has been selected. Electrical signal is reversibly switched between memristor and resistor behaviors by modulating the light incident angle on the device. Moreover, a liquid passivation layer is introduced to achieve stable and reversible exchange between the memristor and WORM behaviors. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Chemical insight into origin of forming-free resistive random-access memory devices

    KAUST Repository

    Wu, X.

    2011-09-29

    We demonstrate the realization of a forming-step free resistive random access memory (RRAM) device using a HfOx/TiOx/HfOx/TiOxmultilayer structure, as a replacement for the conventional HfOx-based single layer structure. High-resolution transmission electron microscopy (HRTEM), along with electron energy loss spectroscopy(EELS)analysis has been carried out to identify the distribution and the role played by Ti in the RRAM stack. Our results show that Ti out-diffusion into the HfOx layer is the chemical cause of forming-free behavior. Moreover, the capability of Ti to change its ionic state in HfOx eases the reduction-oxidation (redox) reaction, thus lead to the RRAM devices performance improvements.

  5. Thermal investigation of a phase change memory device at the nanoscale

    International Nuclear Information System (INIS)

    Battaglia, Jean-Luc; De, Indrayush; Saci, Abdelhak; Kusiak, Andrzej; Sousa, Véronique

    2016-01-01

    New technologies in non-volatile memories have been developed for several years based on phase-change alloys out of which, the most known is the Ge 2 Sb 2 Te 5 . The thermal investigation of the microelectronics device at cell scale is relevant since the heat transfer is the main limiting aspect for the optimal functioning of the device. More particularly, the thermal resistance at interfaces between the constitutive materials is of primary importance. We implemented a scanning thermal microscopy experiment in the 3D mode that allowed to fully characterizing the thermal properties of the cell at the nanoscale. The results lead to understand the 3D heat diffusion in the cell and more particularly the role of the vertical and horizontal interfaces. (paper)

  6. Stretchable carbon nanotube charge-trap floating-gate memory and logic devices for wearable electronics.

    Science.gov (United States)

    Son, Donghee; Koo, Ja Hoon; Song, Jun-Kyul; Kim, Jaemin; Lee, Mincheol; Shim, Hyung Joon; Park, Minjoon; Lee, Minbaek; Kim, Ji Hoon; Kim, Dae-Hyeong

    2015-05-26

    Electronics for wearable applications require soft, flexible, and stretchable materials and designs to overcome the mechanical mismatch between the human body and devices. A key requirement for such wearable electronics is reliable operation with high performance and robustness during various deformations induced by motions. Here, we present materials and device design strategies for the core elements of wearable electronics, such as transistors, charge-trap floating-gate memory units, and various logic gates, with stretchable form factors. The use of semiconducting carbon nanotube networks designed for integration with charge traps and ultrathin dielectric layers meets the performance requirements as well as reliability, proven by detailed material and electrical characterizations using statistics. Serpentine interconnections and neutral mechanical plane layouts further enhance the deformability required for skin-based systems. Repetitive stretching tests and studies in mechanics corroborate the validity of the current approaches.

  7. Current Controlled Relaxation Oscillations in Ge2Sb2Te5-Based Phase Change Memory Devices

    International Nuclear Information System (INIS)

    Lu Yao-Yao; Cai Dao-Lin; Chen Yi-Feng; Wang Yue-Qing; Wei Hong-Yang; Huo Ru-Ru; Song Zhi-Tang

    2016-01-01

    The relaxation oscillation of the phase change memory (PCM) devices based on the Ge 2 Sb 2 Te 5 material is investigated by applying square current pulses. The current pulses with different amplitudes could be accurately given by the independently designed current testing system. The relaxation oscillation across the PCM device could be measured using an oscilloscope. The oscillation duration decreases with time, showing an inner link with the shrinking threshold voltage V th . However, the relaxation oscillation would not terminate until the remaining voltage V on reaches the holding voltage V h . This demonstrates that the relaxation oscillation might be controlled by V on . The increasing current amplitudes could only quicken the oscillation velocity but not be able to eliminate it, which indicates that the relaxation oscillation might be an inherent behavior for the PCM cell. (paper)

  8. Functionalized Graphitic Carbon Nitride for Metal-free, Flexible and Rewritable Nonvolatile Memory Device via Direct Laser-Writing

    Science.gov (United States)

    Zhao, Fei; Cheng, Huhu; Hu, Yue; Song, Long; Zhang, Zhipan; Jiang, Lan; Qu, Liangti

    2014-01-01

    Graphitic carbon nitride nanosheet (g-C3N4-NS) has layered structure similar with graphene nanosheet and presents unusual physicochemical properties due to the s-triazine fragments. But their electronic and electrochemical applications are limited by the relatively poor conductivity. The current work provides the first example that atomically thick g-C3N4-NSs are the ideal candidate as the active insulator layer with tunable conductivity for achieving the high performance memory devices with electrical bistability. Unlike in conventional memory diodes, the g-C3N4-NSs based devices combined with graphene layer electrodes are flexible, metal-free and low cost. The functionalized g-C3N4-NSs exhibit desirable dispersibility and dielectricity which support the all-solution fabrication and high performance of the memory diodes. Moreover, the flexible memory diodes are conveniently fabricated through the fast laser writing process on graphene oxide/g-C3N4-NSs/graphene oxide thin film. The obtained devices not only have the nonvolatile electrical bistability with great retention and endurance, but also show the rewritable memory effect with a reliable ON/OFF ratio of up to 105, which is the highest among all the metal-free flexible memory diodes reported so far, and even higher than those of metal-containing devices. PMID:25073687

  9. Organic ferroelectric memory devices with inkjet-printed polymer electrodes on flexible substrates

    KAUST Repository

    Bhansali, Unnat Sampatraj

    2013-05-01

    Drop-on-demand piezoelectric inkjet-printing technique has been used to fabricate a functional cross-bar array of all-organic ferroelectric memory devices. The polymer-ferroelectric-polymer device consists of a ferroelectric copolymer P(VDF-TrFE) film sandwiched between inkjet-patterned, continuous, orthogonal lines of PEDOT:PSS polymer as the bottom and top electrodes. These devices exhibit well-saturated hysteresis curves with a maximum remnant polarization (Pr) = 6.7 μC/cm2, coercive field (E c) = 55 MV/m and a peak capacitance density of 45 nF/cm2. Our polarization fatigue measurements show that these devices retain ∼100% and 45% of their initial Pr values after 103 and 10 5 stress cycles, respectively. The overall performance and polarization retention characteristics of these ferroelectric capacitors with inkjet-printed polymer electrodes are comparable to metal and spin-cast polymer electrodes suggesting their potential use in large-area flexible electronics. © 2013 Elsevier Ltd. All rights reserved.

  10. Investigation of the Hydrogen Silsesquioxane (HSQ) Electron Resist as Insulating Material in Phase Change Memory Devices

    Science.gov (United States)

    Zhou, Jiao; Ji, Hongkai; Lan, Tian; Yan, Junbing; Zhou, Wenli; Miao, Xiangshui

    2015-01-01

    Phase change random access memory (PCRAM) affords many advantages over conventional solid-state memories due to its nonvolatility, high speed, and scalability. However, high programming current to amorphize the crystalline phase through the melt-quench process of PCRAM, known as the RESET current, poses a critical challenge and has become the most significant obstacle for its widespread commercialization. In this work, an excellent negative tone resist for high resolution electron beam lithography, hydrogen silsesquioxane (HSQ), has been investigated as the insulating material which locally blocks the contact between the bottom electrode and the phase change material in PCRAM devices. Fabrications of the highly scaled HSQ nanopore arrays (as small as 16 nm) are presented. The insulating properties of the HSQ material are studied, especially under e-beam exposure plus thermal curing. Some other critical issues about the thickness adjustment of HSQ films and the influence of the PCRAM electrode on electron scattering in e-beam lithography are discussed. In addition, the HSQ material was successfully integrated into the PCRAM devices, achieving ultra-low RESET current (sub-100 μA), outstanding on/off ratios (~50), and improved endurance at tens of nanometers.

  11. Radiation Testing, Characterization and Qualification Challenges for Modern Microelectronics and Photonics Devices and Technologies

    Science.gov (United States)

    LaBel, Kenneth A.; Cohn, Lewis M.

    2008-01-01

    At GOMAC 2007, we discussed a selection of the challenges for radiation testing of modern semiconductor devices focusing on state-of-the-art memory technologies. This included FLASH non-volatile memories (NVMs) and synchronous dynamic random access memories (SDRAMs). In this presentation, we extend this discussion in device packaging and complexity as well as single event upset (SEU) mechanisms using several technology areas as examples including: system-on-a-chip (SOC) devices and photonic or fiber optic systems. The underlying goal is intended to provoke thought for understanding the limitations and interpretation of radiation testing results.

  12. Pro Android Flash

    CERN Document Server

    Chin, Stephen; Campesato, Oswald

    2011-01-01

    Did you know you can take your Flash skills beyond the browser, allowing you to make apps for Android, iOS and the BlackBerry Tablet OS? Build dynamic apps today starting with the easy-to-use Android smartphones and tablets. Then, take your app to other platforms without writing native code. Pro Android Flash is the definitive guide to building Flash and other rich Internet applications (RIAs) on the Android platform. It covers the most popular RIA frameworks for Android developers - Flash and Flex - and shows how to build rich, immersive user experiences on both Android smartphones and tablet

  13. Flash protection controller

    Science.gov (United States)

    Galbraith, Lee K.

    1981-01-01

    A controller provides a high voltage to maintain an electro-optic shutter in a transparent condition until a flash of light which would be harmful to personnel is sensed by a phototransistor. The controller then shorts the shutter to ground to minimize light transmission to the user and maintains light transmission at the pre-flash level for a predetermined time to allow the flash to subside. A log converter and differential trigger circuit keep the controller from being triggered by other light flashes which are not dangerous.

  14. Multi-floor cascading ferroelectric nanostructures: multiple data writing-based multi-level non-volatile memory devices.

    Science.gov (United States)

    Hyun, Seung; Kwon, Owoong; Lee, Bom-Yi; Seol, Daehee; Park, Beomjin; Lee, Jae Yong; Lee, Ju Hyun; Kim, Yunseok; Kim, Jin Kon

    2016-01-21

    Multiple data writing-based multi-level non-volatile memory has gained strong attention for next-generation memory devices to quickly accommodate an extremely large number of data bits because it is capable of storing multiple data bits in a single memory cell at once. However, all previously reported devices have failed to store a large number of data bits due to the macroscale cell size and have not allowed fast access to the stored data due to slow single data writing. Here, we introduce a novel three-dimensional multi-floor cascading polymeric ferroelectric nanostructure, successfully operating as an individual cell. In one cell, each floor has its own piezoresponse and the piezoresponse of one floor can be modulated by the bias voltage applied to the other floor, which means simultaneously written data bits in both floors can be identified. This could achieve multi-level memory through a multiple data writing process.

  15. Nano-Floating Gate Memory Devices Composed of ZnO Thin-Film Transistors on Flexible Plastics

    Directory of Open Access Journals (Sweden)

    Park Byoungjun

    2011-01-01

    Full Text Available Abstract Nano-floating gate memory devices were fabricated on a flexible plastic substrate by a low-temperature fabrication process. The memory characteristics of ZnO-based thin-film transistors with Al nanoparticles embedded in the gate oxides were investigated in this study. Their electron mobility was found to be 0.18 cm2/V·s and their on/off ratio was in the range of 104–105. The threshold voltages of the programmed and erased states were negligibly changed up to 103 cycles. The flexibility, memory properties, and low-temperature fabrication of the nano-floating gate memory devices described herein suggest that they have potential applications for future flexible integrated electronics.

  16. Foundation Flash CS5 for Designers

    CERN Document Server

    Green, T

    2010-01-01

    Flash is one of the most engaging, innovative, and versatile technologies available - allowing the creation of anything from animated banners and simple cartoons to Rich Internet Applications, interactive videos, and dynamic user interfaces for web sites, kiosks, devices, or DVDs. The possibilities are endless, and now it just got better. Flash CS5 boasts a host of new features, including better support for mobile devices, a whole new animation engine enabling full manipulation of tweens and paths, custom easing, improved inverse kinematics, a revamped timeline, built-in 3D, and much more. Thi

  17. Charge transport and storage of low programming voltage SONOS/MONOS memory devices

    Science.gov (United States)

    Libsch, Frank R.; White, Marvin H.

    1990-01-01

    In this paper, a model based on two carrier conduction (electrons and holes) at both injecting boundaries (semiconductor bulk and gate electrode) is introduced to interpret the ERASE/WRITE characteristics of scaled SONOS devices. The amphoteric statistics describe the positive and negative charging of the deep-level traps in the nitride "memory" layer. Scaled SONOS/MONOS (polysilicon-oxide-nitride-oxide-semiconductor)/(metal-oxide- nitride-oxide-semiconductor) transistors and capacitors with the bottom ('tunnel') oxide layer thickness around 20 Å, the final nitride layer thickness below 100 Å, and the top ('blocking') oxide layer thickness between 35-50 Å, have been fabricated and characterized. The results of the model are consistent with the experimental data, which permits physical insight into the mechanisms of charge injection, transport and storage during the ERASE/WRITE operation. Lattice imaging electron microscopy (TEM), ellipsometry, electrical capacitance, and chemical etchback techniques have been used to determine scaled SONOS/MONOS material parameters. The linear voltage ramp technique, which simultaneously measures the flatband voltage shift and separates the charges at the injecting boundary, and the dynamic pulse techniques of flatband tracking and threshold monitoring, which measure ERASE/WRITE, retention and endurance operations, have been employed to electrically characterize the scaled SONOS/MONOS devices. We have demonstrated a differential, saturated ERASE/WRITE flatband shift of 3.8 V with a ±5 V programming voltage for scaled-down SONOS/MONOS devices with dimensions of 20 Å for the tunnel oxide, 50 Å for the nitride, and 35 Å for the blocking oxide. With ±5 V saturated ERASE/WRITE programming voltages and 10 6 ERASE/WRITE cycles, extrapolated retention gives a projected 10 year 0.5 V memory window at room temperature.

  18. Electrical characterizations of resistive random access memory devices based on GaV{sub 4}S{sub 8} thin layers

    Energy Technology Data Exchange (ETDEWEB)

    Tranchant, J., E-mail: julien.tranchant@cnrs-imn.fr [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Janod, E.; Cario, L.; Corraze, B.; Souchier, E. [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Leclercq, J.-L.; Cremillieu, P. [Université de Lyon, Institut des Nanotechnologies de Lyon (INL), UMR CNRS 5270, Ecole Centrale de Lyon, 36 avenue Guy de Collongue, F 69134 Ecully Cedex (France); Moreau, P.; Besland, M.-P. [Institut des Matériaux Jean Rouxel (IMN), Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France)

    2013-04-30

    The Mott insulator compound GaV{sub 4}S{sub 8} exhibits resistive switching (RS) properties under electric pulses which could be used in the domain of data storage for future replacement of Flash technology. In this work, we present the characterization and the resistive switching performances of three devices containing GaV{sub 4}S{sub 8} thin films with various electrode sizes and geometries, i.e. planar interdigit electrodes and Metal/Insulator/Metal Au/GaV{sub 4}S{sub 8}/Au structures. First, we evidence the good quality of the interfaces between GaV{sub 4}S{sub 8} layers and gold electrodes through transmission electron microscopy observations which allows reliable electrical characterizations. Then, we demonstrate a downscaling effect as the resistive switching amplitude ΔR/R = (R{sub high} − R{sub low}) / R{sub low} increases from a few percents to more than 600% as the electrode size decreases from 50 × 50 μm{sup 2} to 2 × 2 μm{sup 2}. Finally we show that other performances such as cycling endurance, reaching more than 65,000 RS cycles, data retention time till 10 years or writing speed below 100 ns confirm the high potential of GaV{sub 4}S{sub 8} as active material in future resistive random access memories or Mott memories. - Highlights: ► GaV{sub 4}S{sub 8} performance towards memory application is studied on various electrode sizes. ► Endurance in GaV{sub 4}S{sub 8} thin films reaches more than 65,000 cycles. ► We evidence writing/erasing times below 100 ns. ► Downscaling increases the resistance ratio of GaV{sub 4}S{sub 8} Mott memories up to 600%. ► Retention time at room temperature is extrapolated to 10 years.

  19. Facile Synthesis of Co9Se8Quantum Dots as Charge Traps for Flexible Organic Resistive Switching Memory Device.

    Science.gov (United States)

    Zhang, Peng; Xu, Benhua; Gao, Cunxu; Chen, Guilin; Gao, Meizhen

    2016-11-09

    Uniform Co 9 Se 8 quantum dots (CSQDs) were successfully synthesized through a facile solvothermal method. The obtained CSQDs with average size of 3.2 ± 0.1 nm and thickness of 1.8 ± 0.2 nm were demonstrated good stability and strong fluorescence under UV light after being easily dispersed in both of N,N-dimethylformamide (DMF) and deionized water. We demonstrated the flexible resistive switching memory device based on the hybridization of CSQDs and polyvinylpyrrolidone (PVP) (CSQDs-PVP). The device with the Al/CSQDs-PVP/Pt/poly(ethylene terephthalate) (PET) structure represented excellent switching parameters such as high ON/OFF current ratio, low operating voltages, good stability, and flexibility. The flexible resistive switching memory device based on hybridization of CSQDs and PVP has a great potential to be used in flexible and high-performance memory applications.

  20. Multilevel characteristics and memory mechanisms for nonvolatile memory devices based on CuInS2 quantum dot-polymethylmethacrylate nanocomposites

    International Nuclear Information System (INIS)

    Zhou, Yang; Yun, Dong Yeol; Kim, Tae Whan; Kim, Sang Wook

    2014-01-01

    Nonvolatile memory devices based on CuInS 2 (CIS) quantum dots (QDs) embedded in a polymethylmethacrylate (PMMA) layer were fabricated using spin-coating method. The memory window widths of the capacitance-voltage (C-V) curves for the Al/CIS QDs embedded in PMMA layer/p-Si devices were 0.3, 0.6, and 1.0 V for sweep voltages of ±3, ±5, and ±7 V, respectively. Capacitance-cycle data demonstrated that the charge-trapping capability of the devices with an ON/OFF ratio value of 2.81 × 10 −10 was maintained for 8 × 10 3 cycles without significant degradation and that the extrapolation of the ON/OFF ratio value to 1 × 10 6 cycles converged to 2.40 × 10 −10 , indicative of the good stability of the devices. The memory mechanisms for the devices are described on the basis of the C-V curves and the energy-band diagrams

  1. Workload-Based Configuration of MEMS-Based Storage Devices for Mobile Systems

    NARCIS (Netherlands)

    Khatib, M.G.; Miller, E.L.; Hartel, Pieter H.

    2008-01-01

    Because of its small form factor, high capacity, and expected low cost, MEMS-based storage is a suitable storage technology for mobile systems. However, flash memory may outperform MEMS-based storage in terms of performance, and energy-efficiency. The problem is that MEMS-based storage devices have

  2. Semiconductor-Free Nonvolatile Resistive Switching Memory Devices Based on Metal Nanogaps Fabricated on Flexible Substrates via Adhesion Lithography

    KAUST Repository

    Semple, James

    2017-01-02

    Electronic memory cells are of critical importance in modern-day computing devices, including emerging technology sectors such as large-area printed electronics. One technology that has being receiving significant interest in recent years is resistive switching primarily due to its low dimensionality and nonvolatility. Here, we describe the development of resistive switching memory device arrays based on empty aluminum nanogap electrodes. By employing adhesion lithography, a low-temperature and large-area compatible nanogap fabrication technique, dense arrays of memory devices are demonstrated on both rigid and flexible plastic substrates. As-prepared devices exhibit nonvolatile memory operation with stable endurance, resistance ratios >10⁴ and retention times of several months. An intermittent analysis of the electrode microstructure reveals that controlled resistive switching is due to migration of metal from the electrodes into the nanogap under the application of an external electric field. This alternative form of resistive random access memory is promising for use in emerging sectors such as large-area electronics as well as in electronics for harsh environments, e.g., space, high/low temperature, magnetic influences, radiation, vibration, and pressure.

  3. Opportunity of spinel ferrite materials in nonvolatile memory device applications based on their resistive switching performances.

    Science.gov (United States)

    Hu, Wei; Qin, Ni; Wu, Guangheng; Lin, Yanting; Li, Shuwei; Bao, Dinghua

    2012-09-12

    The opportunity of spinel ferrites in nonvolatile memory device applications has been demonstrated by the resistive switching performance characteristics of a Pt/NiFe(2)O(4)/Pt structure, such as low operating voltage, high device yield, long retention time (up to 10(5) s), and good endurance (up to 2.2 × 10(4) cycles). The dominant conduction mechanisms are Ohmic conduction in the low-resistance state and in the lower-voltage region of the high-resistance state and Schottky emission in the higher-voltage region of the high-resistance state. On the basis of measurements of the temperature dependence of the resistances and magnetic properties in different resistance states, we explain the physical mechanism of resistive switching of Pt/NiFe(2)O(4)/Pt devices using the model of formation and rupture of conducting filaments by considering the thermal effect of oxygen vacancies and changes in the valences of cations due to the redox effect.

  4. Current-driven domain wall motion based memory devices: Application to a ratchet ferromagnetic strip

    Science.gov (United States)

    Sánchez-Tejerina, Luis; Martínez, Eduardo; Raposo, Víctor; Alejos, Óscar

    2018-04-01

    Ratchet memories, where perpendicular magnetocristalline anisotropy is tailored so as to precisely control the magnetic transitions, has been recently proven to be a feasible device to store and manipulate data bits. For such devices, it has been shown that the current-driven regime of domain walls can improve their performances with respect to the field-driven one. However, the relaxing time required by the traveling domain walls constitutes a certain drawback if the former regime is considered, since it results in longer device latencies. In order to speed up the bit shifting procedure, it is demonstrated here that the application of a current of inverse polarity during the DW relaxing time may reduce such latencies. The reverse current must be sufficiently high as to drive the DW to the equilibrium position faster than the anisotropy slope itself, but with an amplitude sufficiently low as to avoid DW backward shifting. Alternatively, it is possible to use such a reverse current to increase the proper range of operation for a given relaxing time, i.e., the pair of values of the current amplitude and pulse time that ensures single DW jumps for a certain latency time.

  5. Effect of hydrogen ion beam treatment on Si nanocrystal/SiO2 superlattice-based memory devices

    International Nuclear Information System (INIS)

    Fu, Sheng-Wen; Chen, Hui-Ju; Wu, Hsuan-Ta; Chuang, Bing-Ru; Shih, Chuan-Feng

    2016-01-01

    Graphical abstract: - Highlights: • Memory window and retention properties are improved employing HIBAS technique. • The O/Si ratio and radiative recombination are changed by HIBAS. • Memory properties are affected not only by Si NCs and O/Si ratio but also the RDCs. • The mechanism of hydrogen ion beam alters the memory properties is investigated. - Abstract: This study presents a novel route for synthesizing silicon-rich oxide (SRO)/SiO 2 superlattice-based memory devices with an improved memory window and retention properties. The SiO 2 and SRO superlattices are deposited by reactive sputtering. Specifically, the hydrogen ion beam is used to irradiate the SRO layer immediately after its deposition in the vacuum chamber. The use of the hydrogen ion beam was determined to increase oxygen content and the density of the Si nanocrystals. The memory window increased from 16 to 25.6 V, and the leakage current decreased significantly by two orders, to under ±20 V, for the hydrogen ion beam-prepared devices. This study investigates the mechanism into how hydrogen ion beam treatment alters SRO films and influences memory properties.

  6. Amorphous blue phase III polymer scaffold as a sub-millisecond switching electro-optical memory device

    Science.gov (United States)

    Gandhi, Sahil Sandesh; Kim, Min Su; Hwang, Jeoung-Yeon; Chien, Liang-Chy

    2017-02-01

    We demonstrate the application of the nanostructured scaffold of BPIII as a resuable EO device that retains the BPIII ordering and sub-millisecond EO switching characteristics, that is, "EO-memory" of the original BPIII even after removal of the cholesteric blue phase liquid crystal (LC) and subsequent refilling with different nematic LCs. We also fabricate scaffolds mimicking the isotropic phase and cubic blue phase I (BPI) to demonstrate the versatility of our material system to nano-engineer EO-memory scaffolds of various structures. We envisage that this work will promote new experimental investigations of the mysterious BPIII and the development of novel device architectures and optically functional nanomaterials.

  7. Flash-Type Discrimination

    Science.gov (United States)

    Koshak, William J.

    2010-01-01

    This viewgraph presentation describes the significant progress made in the flash-type discrimination algorithm development. The contents include: 1) Highlights of Progress for GLM-R3 Flash-Type discrimination Algorithm Development; 2) Maximum Group Area (MGA) Data; 3) Retrieval Errors from Simulations; and 4) Preliminary Global-scale Retrieval.

  8. Characterization and Modeling of Charge Trapping and Retention in Novel Multi-Dielectric Nonvolatile Semiconductor Memory Devices.

    Science.gov (United States)

    Roy, Anirban

    This dissertation deals with the synthesis and analysis of new multidielectric memory devices to identify a viable low voltage programmable (5-10V) electrically erasable programmable read only memory (EEPROM) cell for memory densities exceeding 1MB/chip. The memory devices are variations of the triple dielectric silicon dioxide -silicon nitride-silicon dioxide (ONO) structure, where the silicon nitride is the "memory layer". We have developed physically based analytical and numerical models to explain the charge trapping and storage in the scaled down nitride (~100 A) layer. The recombination kinetics in the nitride is modeled with amphoteric traps acting as "memory" centers for electrons and holes injected through the tunneling oxide during programming. We have investigated electron and hole charge separation at the silicon-insulator interface. Surface channel or buried channel transistors can only separate electrons and holes under one gate bias polarity. We have demonstrated, for the first time, charge separation for both gate polarities with the specially designed dual channel (n-buried channel and p-surface channel under the same gate) transistor. We have gained evidence to prove that the memory properties of thin-oxide SONOS devices is dominated by electron and hole recombination in the nitride bulk. We have fabricated ONO memory capacitors and transistors with bottom(tunneling) oxide thicknesses in the range of 15-23A, nitride thicknesses in the range of 50-205A and top(blocking) oxide thicknesses in the range of 17-56A. We have demonstrated 5-10V programming on both uniform and graded(Si-rich composition bounded by N-rich composition) nitride ONO memory devices. We have shown that the graded nitride devices are better than uniform composition nitride for long term (>10 years) charge retention. We have shown that a Au gate electrode reduces electron injection from the gate for large negative gate bias, when compared with Al or n^+ poly gate electrodes. Based

  9. Poly (vinylidene fluoride-trifluoroethylene)/barium titanate nanocomposite for ferroelectric nonvolatile memory devices

    International Nuclear Information System (INIS)

    Valiyaneerilakkal, Uvais; Varghese, Soney

    2013-01-01

    The effect of barium titanate (BaTiO 3 ) nanoparticles (particle size <100 nm) on the ferroelectric properties of poly (vinylidenefluoride-trifluoroethylene) P(VDF-TrFE) copolymer has been studied. Different concentrations of nanoparticles were added to P(VDF-TrFE) using probe sonication, and uniform thin films were made. Polarisation - Electric field (P-E) hysteresis analysis shows an increase in remnant polarization (P r ) and decrease in coercive voltage (V c ). Piezo-response force microscopy analysis shows the switching capability of the polymer composite. The topography and surface roughness was studied using atomic force microscopy. It has been observed that this nanocomposite can be used for the fabrication of non-volatile ferroelectric memory devices.

  10. Poly (vinylidene fluoride-trifluoroethylene/barium titanate nanocomposite for ferroelectric nonvolatile memory devices

    Directory of Open Access Journals (Sweden)

    Uvais Valiyaneerilakkal

    2013-04-01

    Full Text Available The effect of barium titanate (BaTiO3 nanoparticles (particle size <100nm on the ferroelectric properties of poly (vinylidenefluoride-trifluoroethylene P(VDF-TrFE copolymer has been studied. Different concentrations of nanoparticles were added to P(VDF-TrFE using probe sonication, and uniform thin films were made. Polarisation - Electric field (P-E hysteresis analysis shows an increase in remnant polarization (Pr and decrease in coercive voltage (Vc. Piezo-response force microscopy analysis shows the switching capability of the polymer composite. The topography and surface roughness was studied using atomic force microscopy. It has been observed that this nanocomposite can be used for the fabrication of non-volatile ferroelectric memory devices.

  11. All-magnetic magnetoresistive random access memory based on four terminal mCell device

    Science.gov (United States)

    Bromberg, D. M.; Sumbul, H. E.; Zhu, J.-G.; Pileggi, L.

    2015-05-01

    Magnetoresistive random access memory (MRAM) is a promising candidate to enable fast, non-volatile storage on chip. In this paper, we present an MRAM design where each bitcell is comprised entirely of four-terminal magnetic devices ("mCells") with no CMOS access transistors. We show that this design can achieve significant energy and area savings compared to the standard one transistor-one magnetic tunnel junction (1T1MTJ) bitcell based design. We estimate a write energy of ≈5 fJ/bit based on bitline and wordline voltages that operate at less than 100 mV with projected area smaller than that possible with aggressively scaled 10 nm node FinFETs in the 1T1MTJ design.

  12. Memory

    Science.gov (United States)

    ... it has to decide what is worth remembering. Memory is the process of storing and then remembering this information. There are different types of memory. Short-term memory stores information for a few ...

  13. Fabrication of solution processed carbon nanotube embedded polyvinyl alcohol composite film for non-volatile memory device.

    Science.gov (United States)

    Kishore, S Chandra; Pandurangan, A

    2014-03-01

    Carbon nanotubes (CNTs) were synthesized by chemical vapor deposition using nickel coated stainless steel prepared by electrophoretic deposition. CNTs were embedded in polyvinyl alcohol (PVA) which acts as an organic insulator to fabricate Si/PVA/CNT/PVA/Al Metal-Insulator-Semiconductor type memory devices. The effect of CNT content in the charge storage capacity of PVA-CNT composite film was investigated. The hysteresis obtained from the capacitance-voltage (CV) measurement resulted in a memory window of 1.9 V with 3% CNT loading with the gate voltage sweep of +/- 6 V at 1 MHz under room temperature. The memory window of the devices was due to electron injection into the CNT charge storage elements from the top electrode through PVA. The extensive pi-conjugation along the CNT axis traps the electrons in the CNT network. The ON/OFF state current ratio of Si/Al/PVA-CNT/AI device with 3% CNT in PVA demonstrated significantly a lower turn-on voltage of -1 V and a higher ON/OFF state current ratio of 10(7). The non-volatile and reprogrammable switching behavior of the device demonstrated the characteristic of a rewritable memory.

  14. Large scale testing of nitinol shape memory alloy devices for retrofitting of bridges

    International Nuclear Information System (INIS)

    Johnson, Rita; Emmanuel Maragakis, M; Saiid Saiidi, M; Padgett, Jamie E; DesRoches, Reginald

    2008-01-01

    A large scale testing program was conducted to determine the effects of shape memory alloy (SMA) restrainer cables on the seismic performance of in-span hinges of a representative multiple-frame concrete box girder bridge subjected to earthquake excitations. Another objective of the study was to compare the performance of SMA restrainers to that of traditional steel restrainers as restraining devices for reducing hinge displacement and the likelihood of collapse during earthquakes. The results of the tests show that SMA restrainers performed very well as restraining devices. The forces in the SMA and steel restrainers were comparable. However, the SMA restrainer cables had minimal residual strain after repeated loading and exhibited the ability to undergo many cycles with little strength and stiffness degradation. In addition, the hysteretic damping that was observed in the larger ground accelerations demonstrated the ability of the materials to dissipate energy. An analytical study was conducted to assess the anticipated seismic response of the test setup and evaluate the accuracy of the analytical model. The results of the analytical simulation illustrate that the analytical model was able to match the responses from the experimental tests, including peak stresses, strains, forces, and hinge openings

  15. Memory, microprocessor, and ASIC

    CERN Document Server

    Chen, Wai-Kai

    2003-01-01

    System Timing. ROM/PROM/EPROM. SRAM. Embedded Memory. Flash Memories. Dynamic Random Access Memory. Low-Power Memory Circuits. Timing and Signal Integrity Analysis. Microprocessor Design Verification. Microprocessor Layout Method. Architecture. ASIC Design. Logic Synthesis for Field Programmable Gate Array (EPGA) Technology. Testability Concepts and DFT. ATPG and BIST. CAD Tools for BIST/DFT and Delay Faults.

  16. The flash grab effect.

    Science.gov (United States)

    Cavanagh, Patrick; Anstis, Stuart

    2013-10-18

    When an object moves back and forth, its trajectory appears significantly shorter than it actually is. The object appears to stop and reverse well before its actual reversal point, as if there is some averaging of location within a window of about 100 ms (Sinico et al., 2009). Surprisingly, if a bar is flashed at the physical end point of the trajectory, right on top of the object, just as it reverses direction, the flash is also shifted - grabbed by the object - and is seen at the perceived endpoint of the trajectory rather than the physical endpoint. This can shift the perceived location of the flash by as much as 2 or 3 times its physical size and by up to several degrees of visual angle. We first show that the position shift of the flash is generated by the trajectory shortening, as the same shift is seen with or without the flash. The flash itself is only grabbed if it is presented within a small spatiotemporal attraction zone around the physical end point of the trajectory. Any flash falling in that zone is pulled toward the perceived endpoint. The effect scales linearly with speed, up to a maximum, and is independent of the contrast of the moving stimulus once it is above 5%. Finally, we demonstrate that this position shift requires attention. These results reveal a new "flash grab" effect in the family of motion-induced position shifts. Although it most resembles the flash drag effect, it differs from this in the following ways: (1) it has a different temporal profile, (2) it requires attention, (3) it is about 10 times larger. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Rare-Earth Ions in Niobium-Based Devices as a Quantum Memory: Magneto-Optical Effects on Room Temperature Electrical Transport

    Science.gov (United States)

    2016-09-01

    TECHNICAL REPORT 3050 September 2016 Rare-Earth Ions in Niobium-based Devices as a Quantum Memory Magneto-Optical Effects on Room Temperature...Advanced Systems and Applied Sciences Division iii EXECUTIVE SUMMARY Rare-earth ions are useful for the implementation of quantum memory . In...the films and devices so they can properly designed and optimized for utility as quantum memory . We find that the magnetic field has a strong effect

  18. Memory.

    Science.gov (United States)

    McKean, Kevin

    1983-01-01

    Discusses current research (including that involving amnesiacs and snails) into the nature of the memory process, differentiating between and providing examples of "fact" memory and "skill" memory. Suggests that three brain parts (thalamus, fornix, mammilary body) are involved in the memory process. (JN)

  19. The charge storage characteristics of ZrO2 nanocrystallite-based charge trap nonvolatile memory

    International Nuclear Information System (INIS)

    Tang Zhen-Jie; Li Rong; Yin Jiang

    2013-01-01

    ZrO 2 nanocrystallite-based charge trap flash memory capacitors incorporating a (ZrO 2 ) 0.6 (SiO 2 ) 0.4 pseudobinary high-k oxide film as the charge trapping layer were prepared and investigated. The precipitation reaction in the charge trapping layer, forming ZrO 2 nanocrystallites during rapid thermal annealing, was investigated by transmission electron microscopy and X-ray diffraction. It was observed that a ZrO 2 nanocrystallite-based memory capacitor after post-annealing at 850 °C for 60 s exhibits a maximum memory window of about 6.8 V, good endurance and a low charge loss of ∼25% over a period of 10 years (determined by extrapolating the charge loss curve measured experimentally), even at 85 °C. Such 850 °C-annealed memory capacitors appear to be candidates for future nonvolatile flash memory device applications

  20. Umbrella-shaped, memory alloy femoral head support device for treatment of avascular osteonecrosis of the femoral head.

    Science.gov (United States)

    Yu, Xiaowei; Jiang, Wenxiong; Pan, Qi; Wu, Tianyi; Zhang, Yan; Zhou, Zubin; Du, Dongpeng

    2013-07-01

    Avascular necrosis (AVN) of the femoral head is a common orthopaedic disease that is difficult to treat. The purpose of this study was to explore the preliminary efficacy of a self-designed umbrella-shaped memory alloy femoral head support device in the treatment of adult patients with avascular osteonecrosis of the femoral head. The minimally-invasive approach involved curettage of the necrotic tissue of the femoral head, and a self-designed umbrella-shaped, memory alloy femoral head support device was implanted into the collapsed necrotic area to support the collapsed femoral head. Autologous iliac bone and artificial bone were implanted into the support device for the treatment of adult patients with avascular osteonecrosis of the femoral head. The clinical device was used in ten patients and 18 hip joints. The support device failed in one hip joint, which subsequently underwent joint replacement surgery, and the remaining 17 implanted devices were followed up for four to 19 months. The 17 postoperative hip joints were evaluated using the percent-efficacy evaluation method for avascular osteonecrosis of the femoral head in adult patients, and the efficacy rate was 82.35 %. The umbrella-shaped femoral head support device can be used in Ficat stage I, stage II, and stage III adult patients with avascular osteonecrosis of the femoral head.

  1. Flexible nonvolatile memory devices based on Au/PMMA nanocomposites deposited on PEDOT:PSS/Ag nanowire hybrid electrodes

    International Nuclear Information System (INIS)

    Sung, Sihyun; Kim, Tae Whan

    2017-01-01

    Highlights: • Flexible nonvolatile memory (NVM) devices fabricated utilizing Au nanoparticles (AuNPs) embedded in a PMMA layer were fabricated. • The insertion of the PEDOT:PSS layer enhanced the surface uniformity of the AgNW bottom electrode, resulting in improved device performances. • Current-voltage curves for the Al/PMMA:AuNP/PEDOT:PSS/AgNW/PET devices showed clockwise current hysteresis behaviors. • ON/OFF ratio of 1 × 10 3 was maintained for retention times longer than 1 × 10 4 s. • Memory characteristics of the NVM devices before and after bending were similar. - Abstract: Flexible nonvolatile memory (NVM) devices fabricated utilizing Au nanoparticles (AuNPs) embedded in a poly(methylmethacrylate) (PMMA) layer were fabricated on a silver nanowire (AgNW) or a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/AgNW coated on poly(ethylene terephthalate) (PET) substrates. The transmittance and the sheet resistance of the PEDOT:PSS/AgNW hybrid layer were approximately 89% and 50 Ω/sq, respectively, which were comparable to the values for commercial indium-tin-oxide (ITO) electrodes. Current-voltage curves for the Al/PMMA:AuNP/PEDOT:PSS/AgNW/PET devices at 300 K showed clockwise current hysteresis behaviors due to the existence of the AuNPs. The endurance number of ON/OFF switching for the NVM devices was above 30 cycles. An ON/OFF ratio of 1 × 10 3 was maintained for retention times longer than 1 × 10 4 s. The maximum memory margins of the NVM devices before and after bending were approximately 3.4 × 10 3 and 1.4 × 10 3 , respectively. The retention times of the devices before and after bending remained same 1 × 10 4 s. The memory margin and the stability of flexible NVMs fabricated on AgNW electrodes were enhanced due to the embedded PEDOT:PSS buffer layer.

  2. Flexible nonvolatile memory devices based on Au/PMMA nanocomposites deposited on PEDOT:PSS/Ag nanowire hybrid electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Sihyun; Kim, Tae Whan, E-mail: twk@hanyang.ac.kr

    2017-07-31

    Highlights: • Flexible nonvolatile memory (NVM) devices fabricated utilizing Au nanoparticles (AuNPs) embedded in a PMMA layer were fabricated. • The insertion of the PEDOT:PSS layer enhanced the surface uniformity of the AgNW bottom electrode, resulting in improved device performances. • Current-voltage curves for the Al/PMMA:AuNP/PEDOT:PSS/AgNW/PET devices showed clockwise current hysteresis behaviors. • ON/OFF ratio of 1 × 10{sup 3} was maintained for retention times longer than 1 × 10{sup 4} s. • Memory characteristics of the NVM devices before and after bending were similar. - Abstract: Flexible nonvolatile memory (NVM) devices fabricated utilizing Au nanoparticles (AuNPs) embedded in a poly(methylmethacrylate) (PMMA) layer were fabricated on a silver nanowire (AgNW) or a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/AgNW coated on poly(ethylene terephthalate) (PET) substrates. The transmittance and the sheet resistance of the PEDOT:PSS/AgNW hybrid layer were approximately 89% and 50 Ω/sq, respectively, which were comparable to the values for commercial indium-tin-oxide (ITO) electrodes. Current-voltage curves for the Al/PMMA:AuNP/PEDOT:PSS/AgNW/PET devices at 300 K showed clockwise current hysteresis behaviors due to the existence of the AuNPs. The endurance number of ON/OFF switching for the NVM devices was above 30 cycles. An ON/OFF ratio of 1 × 10{sup 3} was maintained for retention times longer than 1 × 10{sup 4} s. The maximum memory margins of the NVM devices before and after bending were approximately 3.4 × 10{sup 3} and 1.4 × 10{sup 3}, respectively. The retention times of the devices before and after bending remained same 1 × 10{sup 4} s. The memory margin and the stability of flexible NVMs fabricated on AgNW electrodes were enhanced due to the embedded PEDOT:PSS buffer layer.

  3. Floods and Flash Flooding

    Science.gov (United States)

    Floods and flash flooding Now is the time to determine your area’s flood risk. If you are not sure whether you ... If you are in a floodplain, consider buying flood insurance. Do not drive around barricades. If your ...

  4. An FPGA-Based Test-Bed for Reliability and Endurance Characterization of Non-Volatile Memory

    Science.gov (United States)

    Rao, Vikram; Patel, Jagdish; Patel, Janak; Namkung, Jeffrey

    2001-01-01

    Memory technologies are divided into two categories. The first category, nonvolatile memories, are traditionally used in read-only or read-mostly applications because of limited write endurance and slow write speed. These memories are derivatives of read only memory (ROM) technology, which includes erasable programmable ROM (EPROM), electrically-erasable programmable ROM (EEPROM), Flash, and more recent ferroelectric non-volatile memory technology. Nonvolatile memories are able to retain data in the absence of power. The second category, volatile memories, are random access memory (RAM) devices including SRAM and DRAM. Writing to these memories is fast and write endurance is unlimited, so they are most often used to store data that change frequently, but they cannot store data in the absence of power. Nonvolatile memory technologies with better future potential are FRAM, Chalcogenide, GMRAM, Tunneling MRAM, and Silicon-Oxide-Nitride-Oxide-Silicon (SONOS) EEPROM.

  5. Write/erase stress relaxation effect on data-retention and read-disturb errors in triple-level cell NAND flash memory with round-robin wear-leveling

    Science.gov (United States)

    Deguchi, Yoshiaki; Kobayashi, Atsuro; Takeuchi, Ken

    2017-04-01

    This study analyzes the influence of the interval of time (t S-P) between write/erase endurance stress and programming the final data for the data-retention and read-disturb error evaluations in 1X nm triple-level cell (TLC) NAND flash memories. During the interval of time after the write/erase endurance stresses, electrons are de-trapped from the tunnel dielectric. Eventually, the data-retention error decreases in read-“cold” data which is infrequently read. By introducing long t S-P, e.g., 3 h, with round-robin wear-leveling, the bit error rate (BER) of the read-cold data can be decreased by 47%. Moreover, in read-“hot” data which is frequently read, the BER decreases because V TH-down errors are decreased by introducing long t S-P in over 600 read cycles, while the BER does not decrease in case of the smaller read cycles (<600) because V TH-up errors increase during the read operations. This work introduces the mechanism of the V TH-down error in read-“hot” data. The measured BER of the read-hot data decreases by 74% by introducing optimal t S-P with round-robin wear-leveling.

  6. Electrical bistabilities and memory stabilities of nonvolatile bistable devices fabricated utilizing C60 molecules embedded in a polymethyl methacrylate layer

    International Nuclear Information System (INIS)

    Cho, Sung Hwan; Lee, Dong Ik; Jung, Jae Hun; Kim, Tae Whan

    2009-01-01

    Current-voltage (I-V) measurements on Al/fullerene (C 60 ) molecules embedded in polymethyl methacrylate/Al devices at 300 K showed a current bistability due to the existence of the C 60 molecules. The on/off ratio of the current bistability for the memory devices was as large as 10 3 . The retention time of the devices was above 2.5 x 10 4 s at room temperature, and cycling endurance tests on these devices indicated that the ON and OFF currents showed no degradation until 50 000 cycles. Carrier transport mechanisms for the nonvolatile bistable devices are described on the basis of the I-V experimental and fitting results.

  7. Electron Mobility Studies of Device Quality InAs/GaAs Short Period Supprlattices Grown by Dynamic Stoichiometry Control and Floating In Flash-off Methods

    Science.gov (United States)

    Grunthaner, F. J.; George, T.; Zang, D. P.; Lewis, J.; Griffen, J.; Tang, X.; Liu, J. K.; Pike, W. T.; Spencer, M. G.

    1993-01-01

    The Strained Layer InGaAs/GaAs system has been the subject of substantial work emphasizing both growth studies and device applications. Relatively few studies have successfully explored the binary InAs on GaAs system because of the difficulties of maintaining a specular growth front and the apparently small value of the critical thickness.

  8. Embedded nonvolatile memory devices with various silicon nitride energy band gaps on glass used for flat panel display applications

    International Nuclear Information System (INIS)

    Son, Dang Ngoc; Van Duy, Nguyen; Jung, Sungwook; Yi, Junsin

    2010-01-01

    Nonvolatile memory (NVM) devices with a nitride–nitride–oxynitride stack structure on a rough poly-silicon (poly-Si) surface were fabricated using a low-temperature poly-Si (LTPS) thin film transistor technology on glass substrates for application of flat panel display (FPD). The plasma-assisted oxidation/nitridation method is used to form a uniform oxynitride with an ultrathin tunneling layer on a rough LTPS surface. The NVMs, using a Si-rich silicon nitride film as a charge-trapping layer, were proposed as one of the solutions for the improvement of device performance such as the program/erase speed, the memory window and the charge retention characteristics. To further improve the vertical scaling and charge retention characteristics of NVM devices, the high-κ high-density N-rich SiN x films are used as a blocking layer. The fabricated NVM devices have outstanding electrical properties, such as a low threshold voltage, a high ON/OFF current ratio, a low subthreshold swing, a low operating voltage of less than ±9 V and a large memory window of 3.7 V, which remained about 1.9 V over a period of 10 years. These characteristics are suitable for electrical switching and data storage with in FPD application

  9. Choice of quantum dot materials for fabricating memory devices with longer storage and faster writing of information

    Science.gov (United States)

    Damodaran, V.; Ghosh, Kaustab

    2016-12-01

    We present theoretical modelling and simulation approach for studying the electron and hole dynamics in various III-V quantum dot (QD) device systems for high performance memory applications. A rigorous computation is carried out by developing a self-consistent Schrödinger Poisson solver for obtaining the potential state of the QD for various applied voltages of the device. A detailed capture as well as emission mechanism of the carriers is elucidated at various operating temperatures ranging from 10 to 300 K. Our results showed suitability of holes in GaSb/GaAs dots for 107 times increase in the duration of data storage and 34 times faster writing capability as compared to InAs/GaAs QDs at room temperature operation. A trade-off is necessary between extending the storage time and increasing the write time by incorporation of high bandgap AlAs barrier. However, a technique is proposed to avoid the trade-off and minimize the write and erase time along with longer storage of data for QD memories with barrier layers. Our computation also reveals greater retention capacity of electrons over holes when localized to the same potential barrier. Applications of these QDs at cryogenic temperatures are also elucidated. Thus, based on our comparative analysis, valuable information is being provided to the device scientist in choosing suitable quantum dot material for memory devices and optimizing its performance.

  10. Comparative study of CNT, silicon nanowire and fullerene embedded multilayer high-k gate dielectric MOS memory devices

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Amretashis; Sarkar, Chandan Kumar [Department of Electronics and Telecommunication Engineering, Jadavpur University, Kolkata-700 032 (India); Requejo, Felix G, E-mail: amretashis@gmail.com [INIFTA, Departmento de Quimica and Departmento de Fisica, Facultad de Ciencias Exactas, Universidad Nacional de La Plata, CC/67-1900, La Plata (Argentina)

    2011-10-12

    Here, we present a comparative theoretical study on stacked (multilayer) gate dielectric MOS memory devices, having a metallic/semiconducting carbon nanotube (CNT), silicon nanowire (Si NW) and fullerene (C60) embedded nitride layer acting as a floating gate. Two types of devices, one with HfO{sub 2}-SiO{sub 2} stack (stack-1) and the other with La{sub 2}O{sub 3}-SiO{sub 2} stack (stack-2) as the tunnel oxide were compared. We evaluated the effective barrier height, the dielectric constant and the effective electron mobility in the composite gate dielectric with the Maxwell-Garnett effective medium theory. Thereafter applying the WKB approximation, we simulated the Fowler-Nordheim (F-N) tunnelling/writing current and the direct tunnelling/leakage current in these devices. We evaluated the I-V characteristics, the charge decay and also the impact of CNT/Si NW aspect ratio and the volume fraction on the effective barrier height and the write voltage, respectively. We also simulated the write time, retention time and the erase time of these MOS devices. Based on the simulation results, it was concluded that the metallic CNT embedded stack-1 device offered the best performance in terms of higher F-N tunnelling current, lower direct tunnelling current and lesser write voltage and write time compared with the other devices. In case of direct tunnelling leakage and retention time it was found that the met CNT embedded stack-2 device showed better characteristics. For erasing, however, the C60 embedded stack-1 device showed the smallest erase time. When compared with earlier reports, it was seen that CNT, C60 and Si NW embedded devices all performed better than nanocrystalline Si embedded MOS non-volatile memories.

  11. Comparative study of CNT, silicon nanowire and fullerene embedded multilayer high-k gate dielectric MOS memory devices

    Science.gov (United States)

    Sengupta, Amretashis; Sarkar, Chandan Kumar; Requejo, Felix G.

    2011-10-01

    Here, we present a comparative theoretical study on stacked (multilayer) gate dielectric MOS memory devices, having a metallic/semiconducting carbon nanotube (CNT), silicon nanowire (Si NW) and fullerene (C60) embedded nitride layer acting as a floating gate. Two types of devices, one with HfO2-SiO2 stack (stack-1) and the other with La2O3-SiO2 stack (stack-2) as the tunnel oxide were compared. We evaluated the effective barrier height, the dielectric constant and the effective electron mobility in the composite gate dielectric with the Maxwell-Garnett effective medium theory. Thereafter applying the WKB approximation, we simulated the Fowler-Nordheim (F-N) tunnelling/writing current and the direct tunnelling/leakage current in these devices. We evaluated the I-V characteristics, the charge decay and also the impact of CNT/Si NW aspect ratio and the volume fraction on the effective barrier height and the write voltage, respectively. We also simulated the write time, retention time and the erase time of these MOS devices. Based on the simulation results, it was concluded that the metallic CNT embedded stack-1 device offered the best performance in terms of higher F-N tunnelling current, lower direct tunnelling current and lesser write voltage and write time compared with the other devices. In case of direct tunnelling leakage and retention time it was found that the met CNT embedded stack-2 device showed better characteristics. For erasing, however, the C60 embedded stack-1 device showed the smallest erase time. When compared with earlier reports, it was seen that CNT, C60 and Si NW embedded devices all performed better than nanocrystalline Si embedded MOS non-volatile memories.

  12. Patient-borne memory device facilitates "point of care" data access.

    Science.gov (United States)

    Overdyk, F J; Haynes, G R; Arvanitis, P J

    1999-01-01

    Although electronic medical records and a central database have made accurate and consistent patient medical information more readily available than with the traditional patient chart, there are many locations in healthcare facilities where terminals for accessing patient data are not available. As patient care becomes decentralized and more patients require anesthesia outside of the operating suites, routing a network-based system to all these locations can be expensive and time consuming. We designed a system whereby essential patient data of interest to anesthesiologists is stored on an electronic memory device the size of a watch battery attached to the patient's wristband. Accessing and editing the data is done via a hand-held computer. This system provides secure patient data storage and management at the "point of care." At the conclusion of the patient's anesthesia-related care, the data is downloaded to a relational database for use in outcome analysis, billing, and quality assurance. After collecting preoperative evaluations, intraoperative data, and postoperative data on 560 patients anesthetized for surgery or other procedures, we find this system to be a reliable, low-cost, medical information management system, with possible application to other medical specialties.

  13. A new isolation device using shape memory alloy and its application for long-span structures

    Science.gov (United States)

    Ding, Youliang; Chen, Xin; Li, Aiqun; Zuo, Xiaobao

    2011-06-01

    The key points to consider in determining the effectiveness of using structural isolation with shape memory alloys (SMA) are the constitutive model, the SMA isolation device and the analysis method. In this paper, a simplified constitutive model based on the classic theory of plasticity is proposed to simulate the behavior of the superelasticity of the SMA, in which the martensite volume fraction is considered as one of the state variables. Comparisons between simulation results and experimental results are made and indicate that the proposed constitutive model yields stress-strain curves that are in good agreement with the experimental ones. Thus, the proposed model can correctly simulate the yield mechanism and energy dissipation capacity of the SMA. Next, in order to make full use of the superelasticity of SMA, a new SMA isolator composed of pre-tensioned SMA bars is presented. Then, a finite element analytical model is established to simulate the behavior of the SMA isolator according to its configuration and simplified constitutive model. Finally, a simplified design method for long-span structures installed with SMA isolators is proposed, which is further used to investigate the isolation effects of a space grid structure. Results show that the SMA isolator can reduce the seismic responses of the structure effectively, which indicates the effectiveness of the proposed SMA isolation method.

  14. Non-volatile memory based on the ferroelectric photovoltaic effect.

    Science.gov (United States)

    Guo, Rui; You, Lu; Zhou, Yang; Lim, Zhi Shiuh; Zou, Xi; Chen, Lang; Ramesh, R; Wang, Junling

    2013-01-01

    The quest for a solid state universal memory with high-storage density, high read/write speed, random access and non-volatility has triggered intense research into new materials and novel device architectures. Though the non-volatile memory market is dominated by flash memory now, it has very low operation speed with ~10 μs programming and ~10 ms erasing time. Furthermore, it can only withstand ~10(5) rewriting cycles, which prevents it from becoming the universal memory. Here we demonstrate that the significant photovoltaic effect of a ferroelectric material, such as BiFeO3 with a band gap in the visible range, can be used to sense the polarization direction non-destructively in a ferroelectric memory. A prototype 16-cell memory based on the cross-bar architecture has been prepared and tested, demonstrating the feasibility of this technique.

  15. Non-volatile memory based on the ferroelectric photovoltaic effect

    Science.gov (United States)

    Guo, Rui; You, Lu; Zhou, Yang; Shiuh Lim, Zhi; Zou, Xi; Chen, Lang; Ramesh, R.; Wang, Junling

    2013-01-01

    The quest for a solid state universal memory with high-storage density, high read/write speed, random access and non-volatility has triggered intense research into new materials and novel device architectures. Though the non-volatile memory market is dominated by flash memory now, it has very low operation speed with ~10 μs programming and ~10 ms erasing time. Furthermore, it can only withstand ~105 rewriting cycles, which prevents it from becoming the universal memory. Here we demonstrate that the significant photovoltaic effect of a ferroelectric material, such as BiFeO3 with a band gap in the visible range, can be used to sense the polarization direction non-destructively in a ferroelectric memory. A prototype 16-cell memory based on the cross-bar architecture has been prepared and tested, demonstrating the feasibility of this technique. PMID:23756366

  16. Electric field mediated non-volatile tuning magnetism in CoPt/PMN-PT heterostructure for magnetoelectric memory devices

    Science.gov (United States)

    Yang, Y. T.; Li, J.; Peng, X. L.; Wang, X. Q.; Wang, D. H.; Cao, Q. Q.; Du, Y. W.

    2016-02-01

    We report a power efficient non-volatile magnetoelectric memory in the CoPt/(011)PMN-PT heterostructure. Two reversible and stable electric field induced coercivity states (i.e., high-HC or low-HC) are obtained due to the strain mediated converse magnetoelectric effect. The reading process of the different coercive field information written by electric fields is demonstrated by using a magnetoresistance read head. This result shows good prospects in the application of novel multiferroic devices.

  17. Enhanced oxygen vacancy diffusion in Ta2O5 resistive memory devices due to infinitely adaptive crystal structure

    Science.gov (United States)

    Jiang, Hao; Stewart, Derek A.

    2016-04-01

    Metal oxide resistive memory devices based on Ta2O5 have demonstrated high switching speed, long endurance, and low set voltage. However, the physical origin of this improved performance is still unclear. Ta2O5 is an important archetype of a class of materials that possess an adaptive crystal structure that can respond easily to the presence of defects. Using first principles nudged elastic band calculations, we show that this adaptive crystal structure leads to low energy barriers for in-plane diffusion of oxygen vacancies in λ phase Ta2O5. Identified diffusion paths are associated with collective motion of neighboring atoms. The overall vacancy diffusion is anisotropic with higher diffusion barriers found for oxygen vacancy movement between Ta-O planes. Coupled with the fact that oxygen vacancy formation energy in Ta2O5 is relatively small, our calculated low diffusion barriers can help explain the low set voltage in Ta2O5 based resistive memory devices. Our work shows that other oxides with adaptive crystal structures could serve as potential candidates for resistive random access memory devices. We also discuss some general characteristics for ideal resistive RAM oxides that could be used in future computational material searches.

  18. Enhancing charge-storage capacity of non-volatile memory devices using template-directed assembly of gold nanoparticles.

    Science.gov (United States)

    Gupta, Raju Kumar; Krishnamoorthy, Sivashankar; Kusuma, Damar Yoga; Lee, Pooi See; Srinivasan, M P

    2012-04-07

    We demonstrate the controlled fabrication of aggregates of gold nanoparticles as a means of enhancing the charge-storage capacity of metal-insulator-semiconductor (MIS) devices by up to 300% at a low biasing voltage of ±4 V. Aggregates of citrate stabilized gold nanoparticles were obtained by directed electrostatic self-assembly onto an underlying nanopattern of positively charged centers. The underlying nanopatterns consist of amine functionalized gold nanoparticle arrays formed using amphiphilic diblock copolymer reverse micelles as templates. The hierarchical self-organization leads to a twelve-fold increase in the number density of the gold nanoparticles and therefore significantly increases the charge storage centers for the MIS device. The MIS structure showed counterclockwise C-V hysteresis curves indicating a good memory effect. A memory window of 1 V was obtained at a low biasing voltage of ±4 V. Furthermore, C-t measurements conducted after applying a charging bias of 4 V showed that the charge was retained beyond 20,000 s. The proposed strategy can be readily adapted for fabricating next generation solution processible non-volatile memory devices. This journal is © The Royal Society of Chemistry 2012

  19. Foundation Flash Cartoon Animation

    CERN Document Server

    Jones, Tim; Rosson, Allan S

    2008-01-01

    One of Flash s most common uses is still animation for cartoons, games, advertising etc, and this book takes a fresh look at the topic, breaking it down pre-production, production, and post production, and looking at each section in detail, and covering topics such as storyboarding, character libraries and camera mechanics like no Flash book has before. The book is written by members of the Emmy award winning ANIMAX team, who have created work for clients such as Disney, AOL, Fox, WWE, ESPN, and Sesame workshop. This book is an opportunity for them to share their secrets, and is written to sui

  20. Flash x-ray

    International Nuclear Information System (INIS)

    Johnson, Q.; Pellinen, D.

    1976-01-01

    The complementary techniques of flash x-ray radiography (FXR) and flash x-ray diffraction (FXD) provide access to a unique domain in nondestructive materials testing. FXR is useful in studies of macroscopic properties during extremely short time intervals, and FXD, the newer technique, is used in studies of microscopic properties. Although these techniques are similar in many respects, there are some substantial differences. FXD generally requires low-voltage, line-radiation sources and extremely accurate timing; FXR is usually less demanding. Phenomena which can be profitably studied by FXR often can also be studied by FXD to permit a complete materials characterization

  1. Conductive bridge random access memory characteristics of SiCN based transparent device due to indium diffusion

    Science.gov (United States)

    Kumar, Dayanand; Aluguri, Rakesh; Chand, Umesh; Tseng, Tseung-Yuen

    2018-03-01

    In this work, the transparent bipolar resistive switching characteristics of a SiCN-based ITO/SiCN/AZO structure due to In diffusion from ITO is studied. The SiCN based device is found to be 80% transparent in the visible wavelength region. This device, with AZO as both top and bottom electrodes, does not show any RRAM property due to deposition of the high quality O2-free SiCN film. Replacing the AZO top electrode with ITO in this device results in good resistive switching (RS) characteristics with a high on/off ratio and long retention. Replacing the SiCN film with ZrO2 also results in excellent RS characteristics due to the formation of an oxygen vacancies filament inside the ZrO2 film. A resistance ratio of on/off is found to be higher in the SiCN based device compared to that of the ZrO2 device. Diffusion of In from ITO into the SiCN film on application of high positive voltage during forming can be attributed to the occurrence of RS in the device, which is confirmed by the analyses of energy dispersive spectroscopy and secondary-ion mass spectrometry. This study shows a pathway for the fabrication of CBRAM based transparent devices for non-volatile memory application.

  2. Towards developing a compact model for magnetization switching in straintronics magnetic random access memory devices

    Science.gov (United States)

    Barangi, Mahmood; Erementchouk, Mikhail; Mazumder, Pinaki

    2016-08-01

    Strain-mediated magnetization switching in a magnetic tunneling junction (MTJ) by exploiting a combination of piezoelectricity and magnetostriction has been proposed as an energy efficient alternative to spin transfer torque (STT) and field induced magnetization switching methods in MTJ-based magnetic random access memories (MRAM). Theoretical studies have shown the inherent advantages of strain-assisted switching, and the dynamic response of the magnetization has been modeled using the Landau-Lifshitz-Gilbert (LLG) equation. However, an attempt to use LLG for simulating dynamics of individual elements in large-scale simulations of multi-megabyte straintronics MRAM leads to extremely time-consuming calculations. Hence, a compact analytical solution, predicting the flipping delay of the magnetization vector in the nanomagnet under stress, combined with a liberal approximation of the LLG dynamics in the straintronics MTJ, can lead to a simplified model of the device suited for fast large-scale simulations of multi-megabyte straintronics MRAMs. In this work, a tensor-based approach is developed to study the dynamic behavior of the stressed nanomagnet. First, using the developed method, the effect of stress on the switching behavior of the magnetization is investigated to realize the margins between the underdamped and overdamped regimes. The latter helps the designer realize the oscillatory behavior of the magnetization when settling along the minor axis, and the dependency of oscillations on the stress level and the damping factor. Next, a theoretical model to predict the flipping delay of the magnetization vector is developed and tested against LLG-based numerical simulations to confirm the accuracy of findings. Lastly, the obtained delay is incorporated into the approximate solutions of the LLG dynamics, in order to create a compact model to liberally and quickly simulate the magnetization dynamics of the MTJ under stress. Using the developed delay equation, the

  3. Towards developing a compact model for magnetization switching in straintronics magnetic random access memory devices

    Energy Technology Data Exchange (ETDEWEB)

    Barangi, Mahmood, E-mail: barangi@umich.edu; Erementchouk, Mikhail; Mazumder, Pinaki [Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109-2121 (United States)

    2016-08-21

    Strain-mediated magnetization switching in a magnetic tunneling junction (MTJ) by exploiting a combination of piezoelectricity and magnetostriction has been proposed as an energy efficient alternative to spin transfer torque (STT) and field induced magnetization switching methods in MTJ-based magnetic random access memories (MRAM). Theoretical studies have shown the inherent advantages of strain-assisted switching, and the dynamic response of the magnetization has been modeled using the Landau-Lifshitz-Gilbert (LLG) equation. However, an attempt to use LLG for simulating dynamics of individual elements in large-scale simulations of multi-megabyte straintronics MRAM leads to extremely time-consuming calculations. Hence, a compact analytical solution, predicting the flipping delay of the magnetization vector in the nanomagnet under stress, combined with a liberal approximation of the LLG dynamics in the straintronics MTJ, can lead to a simplified model of the device suited for fast large-scale simulations of multi-megabyte straintronics MRAMs. In this work, a tensor-based approach is developed to study the dynamic behavior of the stressed nanomagnet. First, using the developed method, the effect of stress on the switching behavior of the magnetization is investigated to realize the margins between the underdamped and overdamped regimes. The latter helps the designer realize the oscillatory behavior of the magnetization when settling along the minor axis, and the dependency of oscillations on the stress level and the damping factor. Next, a theoretical model to predict the flipping delay of the magnetization vector is developed and tested against LLG-based numerical simulations to confirm the accuracy of findings. Lastly, the obtained delay is incorporated into the approximate solutions of the LLG dynamics, in order to create a compact model to liberally and quickly simulate the magnetization dynamics of the MTJ under stress. Using the developed delay equation, the

  4. Towards developing a compact model for magnetization switching in straintronics magnetic random access memory devices

    International Nuclear Information System (INIS)

    Barangi, Mahmood; Erementchouk, Mikhail; Mazumder, Pinaki

    2016-01-01

    Strain-mediated magnetization switching in a magnetic tunneling junction (MTJ) by exploiting a combination of piezoelectricity and magnetostriction has been proposed as an energy efficient alternative to spin transfer torque (STT) and field induced magnetization switching methods in MTJ-based magnetic random access memories (MRAM). Theoretical studies have shown the inherent advantages of strain-assisted switching, and the dynamic response of the magnetization has been modeled using the Landau-Lifshitz-Gilbert (LLG) equation. However, an attempt to use LLG for simulating dynamics of individual elements in large-scale simulations of multi-megabyte straintronics MRAM leads to extremely time-consuming calculations. Hence, a compact analytical solution, predicting the flipping delay of the magnetization vector in the nanomagnet under stress, combined with a liberal approximation of the LLG dynamics in the straintronics MTJ, can lead to a simplified model of the device suited for fast large-scale simulations of multi-megabyte straintronics MRAMs. In this work, a tensor-based approach is developed to study the dynamic behavior of the stressed nanomagnet. First, using the developed method, the effect of stress on the switching behavior of the magnetization is investigated to realize the margins between the underdamped and overdamped regimes. The latter helps the designer realize the oscillatory behavior of the magnetization when settling along the minor axis, and the dependency of oscillations on the stress level and the damping factor. Next, a theoretical model to predict the flipping delay of the magnetization vector is developed and tested against LLG-based numerical simulations to confirm the accuracy of findings. Lastly, the obtained delay is incorporated into the approximate solutions of the LLG dynamics, in order to create a compact model to liberally and quickly simulate the magnetization dynamics of the MTJ under stress. Using the developed delay equation, the

  5. Enhancing Endurance of Huge-Capacity Flash Storage Systems by Selectively Replacing Data Blocks

    Science.gov (United States)

    Wang, Wei-Neng; Ni, Kai; Ma, Jian-She; Wang, Zong-Chao; Zhao, Yi; Pan, Long-Fa

    The wear leveling is a critical factor which significantly impacts the lifetime and the performance of flash storage systems. To extend lifespan and reduce memory requirements, this paper proposed an efficient wear leveling without substantially increasing overhead and without modifying Flash Translation Layer (FTL) for huge-capacity flash storage systems, which is based on selective replacement. Experimental results show that our design levels the wear of different physical blocks with limited system overhead compared with previous algorithms.

  6. Non-volatile memories

    CERN Document Server

    Lacaze, Pierre-Camille

    2014-01-01

    Written for scientists, researchers, and engineers, Non-volatile Memories describes the recent research and implementations in relation to the design of a new generation of non-volatile electronic memories. The objective is to replace existing memories (DRAM, SRAM, EEPROM, Flash, etc.) with a universal memory model likely to reach better performances than the current types of memory: extremely high commutation speeds, high implantation densities and retention time of information of about ten years.

  7. Learning Flash CS4 Professional

    CERN Document Server

    Shupe, Rich

    2009-01-01

    Learning Flash CS4 Professional offers beginners and intermediate Flash developers a unique introduction to the latest version of Adobe's powerful multimedia application. This easy-to-read book is loaded with full-color examples and hands-on tasks to help you master Flash CS4's new motion editor, integrated 3D system, and character control using the new inverse kinematics bones animation system. No previous Flash experience is necessary.

  8. Thermally stable and high ON/OFF ratio non-volatile memory devices based on poly(triphenylamine) with pendent PCBM.

    Science.gov (United States)

    Chen, Chih-Jung; Wu, Jia-Hao; Liou, Guey-Sheng

    2014-04-28

    High ON/OFF ratio electrically bistable non-volatile WORM memory devices were prepared based on poly(triphenylamine) with different amounts of pendent PCBM. With the introduction of 10 wt% PCBM into P-TPA via covalent bonding, a memory device with low switching-ON voltage (0.9 V) and high ON/OFF ratio (10(9)) could be obtained. The device performance remained satisfactory under the heating condition up to 100 °C which is beneficial to maintain device stability for computer application when other components produce heat.

  9. Single-crystal C60 needle/CuPc nanoparticle double floating-gate for low-voltage organic transistors based non-volatile memory devices.

    Science.gov (United States)

    Chang, Hsuan-Chun; Lu, Chien; Liu, Cheng-Liang; Chen, Wen-Chang

    2015-01-07

    Low-voltage organic field-effect transistor memory devices exhibiting a wide memory window, low power consumption, acceptable retention, endurance properties, and tunable memory performance are fabricated. The performance is achieved by employing single-crystal C60 needles and copper phthalocyanine nanoparticles to produce an ambipolar (hole/electron) trapping effect in a double floating-gate architecture. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. WORM memory devices based on conformation change of a PVK derivative with a rigid spacer in side chain

    International Nuclear Information System (INIS)

    Liu Yuanhua; Li Najun; Xia Xuewei; Xu Qingfeng; Ge Jianfeng; Lu Jianmei

    2010-01-01

    A nonvolatile write-once-read-many-times (WORM) memory device based on poly((4-vinylbenzyl)-9H-carbazole) (PVCz) was fabricated by a simple and conventional process. The as-fabricated device was found to be at its OFF state and could be programmed irreversibly to the ON state with a low transition voltage of -1.7 V. The device exhibits a high ON/OFF current ratio of up to 10 6 , high stability in retention time up to 8 h and number of read cycles up to 10 8 under a read voltage of -1.0 V in both ON and OFF states. The results of X-ray diffraction (XRD) and fluorescence emission spectra in different states of PVCz indicate that the electrical bistable phenomenon is caused by the voltage-induced conformation change of the pendant carbazole groups. With high performance, low power consumption and low production cost, the device fabricated with PVCz has a potential application for nonvolatile memory.

  11. Jaan Toomik Flash Artis

    Index Scriptorium Estoniae

    1999-01-01

    1999. a. mai-juuni 'Flash Artis' on ajakirja Eesti korrespondendi Ando Keskküla artikkel Jaan Toomikust. Jaan Toomik on kutsutud esinema Londoni The Photographers' Gallery grupinäitusele, tema videot 'Father and Son' näidatakse Londonis avataval näitusel 'Near and Elsewhere' 11.-24. juunini

  12. Inessa Josing Flash Artis

    Index Scriptorium Estoniae

    1999-01-01

    'Flash Art'i' 1998. a. nov.-dets. numbris Rosa Martínezi artiklis suvisest Manifesta II näitusest Luxembourg'is on positiivselt mainitud ka Inessa Josingut. Illustratsiooniks toodud seitsmest fotost ühel on I. Josingu aknakujundus 'What Must I Do to be Saved?'

  13. Flash Builder and Flash Catalyst The New Workflow

    CERN Document Server

    Peeters, Steven

    2010-01-01

    The Flash Platform is changing. Flash Builder and Flash Catalyst have brought a new separation of design and coding to web development that enables a much more efficient and streamlined workflow. For designers and developers used to the close confines of Flash, this is a hugely liberating but at first alien concept. This book teaches you the new workflow for the Flash platform. It gives an overview of the technologies involved and provides you with real-world project examples and best-practice guidelines to get from design to implementation with the tools at hand. * Includes many examples* Foc

  14. Impact of continuing scaling on the device performance of 3D cylindrical junction-less charge trapping memory

    International Nuclear Information System (INIS)

    Li Xinkai; Huo Zongliang; Jin Lei; Jiang Dandan; Hong Peizhen; Xu Qiang; Tang Zhaoyun; Li Chunlong; Ye Tianchun

    2015-01-01

    This work presents a comprehensive analysis of 3D cylindrical junction-less charge trapping memory device performance regarding continuous scaling of the structure dimensions. The key device performance, such as program/erase speed, vertical charge loss, and lateral charge migration under high temperature are intensively studied using the Sentaurus 3D device simulator. Although scaling of channel radius is beneficial for operation speed improvement, it leads to a retention challenge due to vertical leakage, especially enhanced charge loss through TPO. Scaling of gate length not only decreases the program/erase speed but also leads to worse lateral charge migration. Scaling of spacer length is critical for the interference of adjacent cells and should be carefully optimized according to specific cell operation conditions. The gate stack shape is also found to be an important factor affecting the lateral charge migration. Our results provide guidance for high density and high reliability 3D CTM integration. (paper)

  15. 3D Printing of Shape Memory Polymers for Flexible Electronic Devices.

    Science.gov (United States)

    Zarek, Matt; Layani, Michael; Cooperstein, Ido; Sachyani, Ela; Cohn, Daniel; Magdassi, Shlomo

    2016-06-01

    The formation of 3D objects composed of shape memory polymers for flexible electronics is described. Layer-by-layer photopolymerization of methacrylated semicrystalline molten macromonomers by a 3D digital light processing printer enables rapid fabrication of complex objects and imparts shape memory functionality for electrical circuits. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Nanometer-scale temperature imaging for independent observation of Joule and Peltier effects in phase change memory devices.

    Science.gov (United States)

    Grosse, Kyle L; Pop, Eric; King, William P

    2014-09-01

    This paper reports a technique for independent observation of nanometer-scale Joule heating and thermoelectric effects, using atomic force microscopy (AFM) based measurements of nanometer-scale temperature fields. When electrical current flows through nanoscale devices and contacts the temperature distribution is governed by both Joule and thermoelectric effects. When the device is driven by an electrical current that is both periodic and bipolar, the temperature rise due to the Joule effect is at a different harmonic than the temperature rise due to the Peltier effect. An AFM tip scanning over the device can simultaneously measure all of the relevant harmonic responses, such that the Joule effect and the Peltier effect can be independently measured. Here we demonstrate the efficacy of the technique by measuring Joule and Peltier effects in phase change memory devices. By comparing the observed temperature responses of these working devices, we measure the device thermopower, which is in the range of 30 ± 3 to 250 ± 10 μV K(-1). This technique could facilitate improved measurements of thermoelectric phenomena and properties at the nanometer-scale.

  17. Nanometer-scale temperature imaging for independent observation of Joule and Peltier effects in phase change memory devices

    Energy Technology Data Exchange (ETDEWEB)

    Grosse, Kyle L. [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Pop, Eric [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); King, William P., E-mail: wpk@illinois.edu [Department of Mechanical Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Departments of Electrical and Computer Engineering and Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    2014-09-15

    This paper reports a technique for independent observation of nanometer-scale Joule heating and thermoelectric effects, using atomic force microscopy (AFM) based measurements of nanometer-scale temperature fields. When electrical current flows through nanoscale devices and contacts the temperature distribution is governed by both Joule and thermoelectric effects. When the device is driven by an electrical current that is both periodic and bipolar, the temperature rise due to the Joule effect is at a different harmonic than the temperature rise due to the Peltier effect. An AFM tip scanning over the device can simultaneously measure all of the relevant harmonic responses, such that the Joule effect and the Peltier effect can be independently measured. Here we demonstrate the efficacy of the technique by measuring Joule and Peltier effects in phase change memory devices. By comparing the observed temperature responses of these working devices, we measure the device thermopower, which is in the range of 30 ± 3 to 250 ± 10 μV K{sup −1}. This technique could facilitate improved measurements of thermoelectric phenomena and properties at the nanometer-scale.

  18. Layer-by-layer charging in non-volatile memory devices using embedded sub-2 nm platinum nanoparticles

    International Nuclear Information System (INIS)

    Ramalingam, Balavinayagam; Zheng, Haisheng; Gangopadhyay, Shubhra

    2014-01-01

    In this work, we demonstrate multi-level operation of a non-volatile memory metal oxide semiconductor capacitor by controlled layer-by-layer charging of platinum nanoparticle (PtNP) floating gate devices with defined gate voltage bias ranges. The device consists of two layers of ultra-fine, sub-2 nm PtNPs integrated between Al 2 O 3 tunneling and separation layers. PtNP size and interparticle distance were varied to control the particle self-capacitance and associated Coulomb charging energy. Likewise, the tunneling layer thicknesses were also varied to control electron tunneling to the first and second PtNP layers. The final device configuration with optimal charging behavior and multi-level programming was attained with a 3 nm Al 2 O 3 initial tunneling layer, initial PtNP layer with particle size 0.54 ± 0.12 nm and interparticle distance 4.65 ± 2.09 nm, 3 nm Al 2 O 3 layer to separate the PtNP layers, and second particle layer with 1.11 ± 0.28 nm PtNP size and interparticle distance 2.75 ± 1.05 nm. In this device, the memory window of the first PtNP layer saturated over a programming bias range of 7 V to 14 V, after which the second PtNP layer starts charging, exhibiting a multi-step memory window with layer-by-layer charging

  19. Electrical reliability, multilevel data storage and mechanical stability of MoS2-PMMA nanocomposite-based non-volatile memory device

    International Nuclear Information System (INIS)

    Bhattacharjee, Snigdha; Sarkar, Pranab Kumar; Roy, Asim; Prajapat, Manoj

    2017-01-01

    Molybdenum disulfide (MoS 2 ) is of great interest for its applicability in various optoelectronic devices. Here we report the resistive switching properties of polymethylmethacrylate embedding MoS 2 nano-crystals. The devices are developed on an ITO-coated PET substrate with copper as the top electrode. Systematic evaluation of resistive switching parameters, on the basis of MoS 2 content, suggests non-volatile memory characteristics. A decent ON/OFF ratio, high retention time and long endurance of 3  ×  10 3 , 10 5 s and 10 5 cycles are respectively recorded in a device with 1 weight percent (wt%) of MoS 2 . The bending cyclic measurements confirm the flexibility of the memory devices with good electrical reliability as well as mechanical stability. In addition, multilevel storage has been demonstrated by controlling the current compliance and span of voltage sweeping in the memory device. (paper)

  20. Why Flash Type Matters: A Statistical Analysis

    Science.gov (United States)

    Mecikalski, Retha M.; Bitzer, Phillip M.; Carey, Lawrence D.

    2017-09-01

    While the majority of research only differentiates between intracloud (IC) and cloud-to-ground (CG) flashes, there exists a third flash type, known as hybrid flashes. These flashes have extensive IC components as well as return strokes to ground but are misclassified as CG flashes in current flash type analyses due to the presence of a return stroke. In an effort to show that IC, CG, and hybrid flashes should be separately classified, the two-sample Kolmogorov-Smirnov (KS) test was applied to the flash sizes, flash initiation, and flash propagation altitudes for each of the three flash types. The KS test statistically showed that IC, CG, and hybrid flashes do not have the same parent distributions and thus should be separately classified. Separate classification of hybrid flashes will lead to improved lightning-related research, because unambiguously classified hybrid flashes occur on the same order of magnitude as CG flashes for multicellular storms.

  1. Development of Ultrafast Laser Flash Methods for Measuring Thermophysical Properties of Thin Films and Boundary Thermal Resistances

    Science.gov (United States)

    Baba, Tetsuya; Taketoshi, Naoyuki; Yagi, Takashi

    2011-11-01

    Reliable thermophysical property values of thin films are important to develop advanced industrial technologies such as highly integrated electronic devices, phase-change memories, magneto-optical disks, light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), semiconductor lasers (LDs), flat-panel displays, and power electronic devices. In order to meet these requirements, the National Metrology Institute of Japan of the National Institute of Advanced Industrial Science and Technology (NMIJ/AIST) has developed ultrafast laser flash methods heated by picosecond pulse or nanosecond pulse with the same geometrical configuration as the laser flash method, which is the standard method to measure the thermal diffusivity of bulk materials. Since these pulsed light heating methods induce one-dimensional heat diffusion across a well-defined length of the specimen thickness, the absolute value of thermal diffusivity across thin films can be measured reliably. Using these ultrafast laser flash methods, the thermal diffusivity of each layer of multilayered thin films and the boundary thermal resistance between the layers can be determined from the observed transient temperature curves based on the response function method. The thermophysical properties of various thin films important for modern industries such as the transparent conductive films used for flat-panel displays, hard coating films, and multilayered films of next-generation phase-change optical disks have been measured by these methods.

  2. Embedded system in FPGA-based LLRF controller for FLASH

    Science.gov (United States)

    Szewinski, Jaroslaw; Pucyk, Piotr; Jalmuzna, Wojciech; Fafara, Przemyslaw; Pieciukiewicz, Marcin; Romaniuk, Ryszard; Pozniak, Krzysztof T.

    2006-10-01

    FPGA devices are often used in High Energy Physics and accelerator technology experiments, where the highest technologies are needed. To make FPGA based systems more flexible, common technique is to provide SoC (System on a Chip) solution in the FPGA, which is in most cases a CPU unit. Such a combination gives possibility to balance between hardware and software implementation of particular task. SoC solution on FPGA can be very flexible, because in simplest cases no additional hardware is needed to run programs on CPU, and when system has such devices like UART, SDRAM memory, mass storage and network interface, it can handle full featured operating system such as Linux or VxWorks. Embedded process can be set up in different configurations, depending on the available resources on board, so every user can adjust system to his own needs. Embedded systems can be also used to perform partial self-reconfiguration of FPGA logic of the chip, on which the system is running. This paper will also present some results on SoC implementations in a Low Level RF system under design for the VUV Free Electron Laser, FLASH, DESY, Hamburg.

  3. Nonvolatile memory design magnetic, resistive, and phase change

    CERN Document Server

    Li, Hai

    2011-01-01

    The manufacture of flash memory, which is the dominant nonvolatile memory technology, is facing severe technical barriers. So much so, that some emerging technologies have been proposed as alternatives to flash memory in the nano-regime. Nonvolatile Memory Design: Magnetic, Resistive, and Phase Changing introduces three promising candidates: phase-change memory, magnetic random access memory, and resistive random access memory. The text illustrates the fundamental storage mechanism of these technologies and examines their differences from flash memory techniques. Based on the latest advances,

  4. Biologically active nanocomposite of DNA-PbS nanoparticles: A new material for non-volatile memory devices

    Science.gov (United States)

    Murgunde, B. K.; Rabinal, M. K.; Kalasad, M. N.

    2018-01-01

    Composite films of deoxyribonucleic acid (DNA) and lead sulfide (PbS) nanoparticles are prepared to fabricate biological memory devices. A simple solution based electrografting is developed to deposit large (few cm2) uniform films of DNA:PbS on conducting substrates. The films are studied by X-ray photoelectron spectroscopy, field emission SEM, FTIR and optical spectroscopy to understand their properties. Charge transport measurements are carried out on ITO-DNA:PbS-metal junctions by cyclic voltage scans, electrical bi-stability is observed with ON/OFF ratio more than ∼104 times with good stability and endurance, such performance being rarely reported. The observed results are interpreted in the light of strong electrostatic binding of nanoparticles and DNA stands, which leads doping of Pb atoms into DNA. As a result, these devices exhibit negative differential resistance (NDR) effect due to oxidation of doped metal atoms. These composites can be the potential materials in the development of new generation non-volatile memory devices.

  5. Investigations on the effects of electrode materials on the device characteristics of ferroelectric memory thin film transistors fabricated on flexible substrates

    Science.gov (United States)

    Yang, Ji-Hee; Yun, Da-Jeong; Seo, Gi-Ho; Kim, Seong-Min; Yoon, Myung-Han; Yoon, Sung-Min

    2018-03-01

    For flexible memory device applications, we propose memory thin-film transistors using an organic ferroelectric poly(vinylidene fluoride-trifluoroethylene) [P(VDF-TrFE)] gate insulator and an amorphous In-Ga-Zn-O (a-IGZO) active channel. The effects of electrode materials and their deposition methods on the characteristics of memory devices exploiting the ferroelectric field effect were investigated for the proposed ferroelectric memory thin-film transistors (Fe-MTFTs) at flat and bending states. It was found that the plasma-induced sputtering deposition and mechanical brittleness of the indium-tin oxide (ITO) markedly degraded the ferroelectric-field-effect-driven memory window and bending characteristics of the Fe-MTFTs. The replacement of ITO electrodes with metal aluminum (Al) electrodes prepared by plasma-free thermal evaporation greatly enhanced the memory device characteristics even under bending conditions owing to their mechanical ductility. Furthermore, poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT:PSS) was introduced to achieve robust bending performance under extreme mechanical stress. The Fe-MTFTs using PEDOT:PSS source/drain electrodes were successfully fabricated and showed the potential for use as flexible memory devices. The suitable choice of electrode materials employed for the Fe-MTFTs is concluded to be one of the most important control parameters for highly functional flexible Fe-MTFTs.

  6. Memory

    OpenAIRE

    Wager, Nadia

    2017-01-01

    This chapter will explore a response to traumatic victimisation which has divided the opinions of psychologists at an exponential rate. We will be examining amnesia for memories of childhood sexual abuse and the potential to recover these memories in adulthood. Whilst this phenomenon is generally accepted in clinical circles, it is seen as highly contentious amongst research psychologists, particularly experimental cognitive psychologists. The chapter will begin with a real case study of a wo...

  7. Scalable processes for fabricating non-volatile memory devices using self-assembled 2D arrays of gold nanoparticles as charge storage nodes.

    Science.gov (United States)

    Muralidharan, Girish; Bhat, Navakanta; Santhanam, Venugopal

    2011-11-01

    We propose robust and scalable processes for the fabrication of floating gate devices using ordered arrays of 7 nm size gold nanoparticles as charge storage nodes. The proposed strategy can be readily adapted for fabricating next generation (sub-20 nm node) non-volatile memory devices.

  8. Feasibility study of using a Zener diode as the selection device for bipolar RRAM and WORM memory arrays

    International Nuclear Information System (INIS)

    Li, Yingtao; Fu, Liping; Tao, Chunlan; Jiang, Xinyu; Sun, Pengxiao

    2014-01-01

    Cross-bar arrays are usually used for the high density application of resistive random access memory (RRAM) devices. However, cross-talk interference limits an increase in the integration density. In this paper, the Zener diode is proposed as a selection device to suppress the sneak current in bipolar RRAM arrays. Measurement results show that the Zener diode can act as a good selection device, and the sneak current can be effectively suppressed. The readout margin is sufficiently improved compared to that obtained without the selection device. Due to the improvement for the reading disturbance, the size of the cross-bar array can be enhanced to more than 10 3  × 10 3 . Furthermore, the possibility of using a write-once-read-many-times (WORM) cross-bar array is also demonstrated by connecting the Zener diode and the bipolar RRAM in series. These results strongly suggest that using a Zener diode as a selection device opens up great opportunities to realize high density bipolar RRAM arrays. (paper)

  9. Physics Flash August 2016

    Energy Technology Data Exchange (ETDEWEB)

    Kippen, Karen Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-25

    Physics Flash is the newsletter for the Physics Division at Los Alamos National Laboratory. This newsletter is for August 2016. The following topics are covered: "Accomplishments in the Trident Laser Facility", "David Meyerhofer elected as chair-elect APS Nominating Committee", "HAWC searches for gamma rays from dark matter", "Proton Radiography Facility commissions electromagnetic magnifier", and "Cosmic ray muon computed tomography of spent nuclear fuel in dry storage casks."

  10. The lightning flash

    CERN Document Server

    Cooray, Vernon

    2014-01-01

    With contributions from today's leading lightning engineers and researchers, this updated 2nd edition of Vernon Cooray's classic text, The Lightning Flash provides the reader with an essential introduction to lightning and its impact on electrical and electronic equipment. Providing the reader with a thorough background into almost every aspect of lightning and its impact on electrical and electronic equipment, this new edition is updated throughout and features eight new chapters that bring the science up to date.

  11. Coherent imaging at FLASH

    International Nuclear Information System (INIS)

    Chapman, H N; Bajt, S; Duesterer, S; Treusch, R; Barty, A; Benner, W H; Bogan, M J; Frank, M; Hau-Riege, S P; Woods, B W; Boutet, S; Cavalleri, A; Hajdu, J; Iwan, B; Seibert, M M; Timneanu, N; Marchesini, S; Sakdinawat, A; Sokolowski-Tinten, K

    2009-01-01

    We have carried out high-resolution single-pulse coherent diffractive imaging at the FLASH free-electron laser. The intense focused FEL pulse gives a high-resolution low-noise coherent diffraction pattern of an object before that object turns into a plasma and explodes. In particular we are developing imaging of biological specimens beyond conventional radiation damage resolution limits, developing imaging of ultrafast processes, and testing methods to characterize and perform single-particle imaging.

  12. Physics Flash December 2016

    Energy Technology Data Exchange (ETDEWEB)

    Kippen, Karen Elizabeth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). ADEPS Communications

    2016-12-01

    This is the December 2016 issue of Physics Flash, the newsletter of the Physics Division of Los Alamos National Laboratory (LANL). In this issue, the following topics are covered: Novel liquid helium technique to aid highly sensitive search for a neutron electrical dipole moment; Silverleaf: Prototype Red Sage experiments performed at Q-site; John L. Kline named 2016 APS Fellow; Physics students in the news; First Entropy Engine quantum random number generator hits the market; and celebrating service.

  13. 3D Printing: 3D Printing of Shape Memory Polymers for Flexible Electronic Devices (Adv. Mater. 22/2016).

    Science.gov (United States)

    Zarek, Matt; Layani, Michael; Cooperstein, Ido; Sachyani, Ela; Cohn, Daniel; Magdassi, Shlomo

    2016-06-01

    On page 4449, D. Cohn, S. Magdassi, and co-workers describe a general and facile method based on 3D printing of methacrylated macromonomers to fabricate shape-memory objects that can be used in flexible and responsive electrical circuits. Such responsive objects can be used in the fabrication of soft robotics, minimal invasive medical devices, sensors, and wearable electronics. The use of 3D printing overcomes the poor processing characteristics of thermosets and enables complex geometries that are not easily accessible by other techniques. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. A resistance ratio change phenomenon observed in Al doped ZnO (AZO)/Cu(In1-xGax)Se2/Mo resistive switching memory device

    Science.gov (United States)

    Guo, Tao; Sun, Bai; Mao, Shuangsuo; Zhu, Shouhui; Xia, Yudong; Wang, Hongyan; Zhao, Yong; Yu, Zhou

    2018-03-01

    In this work, the Cu(In1-xGax)Se2 (CIGS), Al doped ZnO (AZO) and Mo has been used for constructing a resistive switching device with AZO/CIGS/Mo sandwich structure grown on a transparent glass substrate. The device represents a high-performance memory characteristics under ambient temperature. In particularly, a resistance ratio change phenomenon have been observed in our device for the first time.

  15. Forming-free resistive switching characteristics of Ag/CeO2/Pt devices with a large memory window

    Science.gov (United States)

    Zheng, Hong; Kim, Hyung Jun; Yang, Paul; Park, Jong-Sung; Kim, Dong Wook; Lee, Hyun Ho; Kang, Chi Jung; Yoon, Tae-Sik

    2017-05-01

    Ag/CeO2(∼45 nm)/Pt devices exhibited forming-free bipolar resistive switching with a large memory window (low-resistance-state (LRS)/high-resistance-state (HRS) ratio >106) at a low switching voltage (104) at a pulse operation (±5 V, 50 μs). The high oxygen ionic conductivity of the CeO2 layer as well as the migration of silver facilitated the formation of filament for the transition to LRS at a low voltage without a high voltage forming operation. Also, a certain amount of defects in the CeO2 layer was required for stable HRS with space-charge-limited-conduction, which was confirmed comparing the devices with non-annealed and annealed CeO2 layers.

  16. Superior memory efficiency of quantum devices for the simulation of continuous-time stochastic processes

    Science.gov (United States)

    Elliott, Thomas J.; Gu, Mile

    2018-03-01

    Continuous-time stochastic processes pervade everyday experience, and the simulation of models of these processes is of great utility. Classical models of systems operating in continuous-time must typically track an unbounded amount of information about past behaviour, even for relatively simple models, enforcing limits on precision due to the finite memory of the machine. However, quantum machines can require less information about the past than even their optimal classical counterparts to simulate the future of discrete-time processes, and we demonstrate that this advantage extends to the continuous-time regime. Moreover, we show that this reduction in the memory requirement can be unboundedly large, allowing for arbitrary precision even with a finite quantum memory. We provide a systematic method for finding superior quantum constructions, and a protocol for analogue simulation of continuous-time renewal processes with a quantum machine.

  17. An ultrafast programmable electrical tester for enabling time-resolved, sub-nanosecond switching dynamics and programming of nanoscale memory devices

    Science.gov (United States)

    Shukla, Krishna Dayal; Saxena, Nishant; Manivannan, Anbarasu

    2017-12-01

    Recent advancements in commercialization of high-speed non-volatile electronic memories including phase change memory (PCM) have shown potential not only for advanced data storage but also for novel computing concepts. However, an in-depth understanding on ultrafast electrical switching dynamics is a key challenge for defining the ultimate speed of nanoscale memory devices that demands for an unconventional electrical setup, specifically capable of handling extremely fast electrical pulses. In the present work, an ultrafast programmable electrical tester (PET) setup has been developed exceptionally for unravelling time-resolved electrical switching dynamics and programming characteristics of nanoscale memory devices at the picosecond (ps) time scale. This setup consists of novel high-frequency contact-boards carefully designed to capture extremely fast switching transient characteristics within 200 ± 25 ps using time-resolved current-voltage measurements. All the instruments in the system are synchronized using LabVIEW, which helps to achieve various programming characteristics such as voltage-dependent transient parameters, read/write operations, and endurance test of memory devices systematically using short voltage pulses having pulse parameters varied from 1 ns rise/fall time and 1.5 ns pulse width (full width half maximum). Furthermore, the setup has successfully demonstrated strikingly one order faster switching characteristics of Ag5In5Sb60Te30 (AIST) PCM devices within 250 ps. Hence, this novel electrical setup would be immensely helpful for realizing the ultimate speed limits of various high-speed memory technologies for future computing.

  18. Development of a thermodynamic control system for the Fontan circulation pulsation device using shape memory alloy fibers.

    Science.gov (United States)

    Yamada, Akihiro; Shiraishi, Yasuyuki; Miura, Hidekazu; Hashem, Hashem Mohamed Omran; Tsuboko, Yusuke; Yamagishi, Masaaki; Yambe, Tomoyuki

    2015-09-01

    The Fontan procedure is one of the common surgical treatments for circulatory reconstruction in pediatric patients with congenital heart disease. In Fontan circulation, low pulsatility may induce localized lung ischemia and may impair the development of pulmonary peripheral endothelial cells. To promote pulmonary circulation in Fontan circulation, we have been developing a pediatric pulmonary circulatory pulsation device using shape memory alloy fibers attached from the outside of total cavopulmonary connection. In this study, we developed a new thermal control system for the device and examined its functions. We mounted on the device 16 fibers connected in parallel around an ePTFE graft circumferentially. To provide optimized contraction, we designed the new thermal control system. The system consisted of a thermistor, a pressure sensor, and a regulator that was controlled by the adaptive thermodynamic transfer functions. We monitored the parameters and calculated heat transfer function as well as pressure distribution on the graft surface. Then we examined and compared the dynamic contractile pressure and changes in surface temperature. As a result, by the application of the control based on the new feedback system analysis, the circumferential contractile pressure increased by 35%. The adaptive thermodynamic regulation was useful for the selection of alternative thresholds of the surface temperature of the graft. The system could achieve effective contraction for the pulsatile flow generation by the device.

  19. Phenomenological analysis of random telegraph noise in amorphous TiOx-based bipolar resistive switching random access memory devices.

    Science.gov (United States)

    Lee, Jung-Kyu; Lee, Ju-Wan; Bae, Jong-Ho; Park, Jinwon; Chung, Sung-Woong; Roh, Jae Sung; Hong, Sung-Joo; Lee, Jong-Ho

    2012-07-01

    As dimensions of resistive random access memories (RRAMs) devices continue to shrink, the low-frequency noise of nanoscale devices has become increasingly important in evaluating the device reliability. Thus, we investigated random telegraph noise (RTN) caused by capture and emission of an electron at traps. We physically analyzed capture and emission processes through systematic measurements of amorphous TiOx (alpha-TiOx)-based bipolar RRAMs. RTNs were observed during high-resistance state (HRS) in most devices. However, discrete switching behavior was scarcely observed in low-resistance state (LRS) as most of traps in the alpha-TiOx were filled with mobile ions such as O2- in LRS. The capture and emission processes of an electron at traps are largely divided into two groups: (1) both capture and emission processes are mainly affected by electric field; and (2) one of the capture and emission processes is only influenced by the thermal process. This paper provides fundamental physics required to understand the mechanism of RTNs in alpha-TiOx-based bipolar RRAMs.

  20. Development of a high capacity bubble domain memory element and related epitaxial garnet materials for application in spacecraft data recorders. Item 2: The optimization of material-device parameters for application in bubble domain memory elements for spacecraft data recorders

    Science.gov (United States)

    Besser, P. J.

    1976-01-01

    Bubble domain materials and devices are discussed. One of the materials development goals was a materials system suitable for operation of 16 micrometer period bubble domain devices at 150 kHz over the temperature range -10 C to +60 C. Several material compositions and hard bubble suppression techniques were characterized and the most promising candidates were evaluated in device structures. The technique of pulsed laser stroboscopic microscopy was used to characterize bubble dynamic properties and device performance at 150 kHz. Techniques for large area LPE film growth were developed as a separate task. Device studies included detector optimization, passive replicator design and test and on-chip bridge evaluation. As a technology demonstration an 8 chip memory cell was designed, tested and delivered. The memory elements used in the cell were 10 kilobit serial registers.

  1. Nonvolatile and Cryogenic-compatible Quantum Memory Devices (QuMEM)

    Science.gov (United States)

    2016-06-01

    AND SUPER - CONDUCTOR CRITICAL CURRENT WITH MODIFICATION OF BARRIER PROPERTIEIS AND IONIC CONFIGURATION...3, pp. 760–769. Nayfeh, O. M., D. A. Antoniadis, K. Mantey, and M. H. Nayfeh. 2007. “Memory Effects in Metal- Oxide-Semiconductor Capacitors

  2. Low-temperature process steps for realization of non-volatile memory devices

    NARCIS (Netherlands)

    Brunets, I.; Boogaard, A.; Aarnink, Antonius A.I.; Kovalgin, Alexeij Y.; Wolters, Robertus A.M.; Holleman, J.; Schmitz, Jurriaan

    2007-01-01

    In this work, the low-temperature process steps required for the realization of nano-crystal non-volatile memory cells are discussed. An amorphous silicon film, crystallized using a diode pumped solid state green laser irradiating at 532 nm, is proposed as an active layer. The deposition of the

  3. Memories.

    Science.gov (United States)

    Brand, Judith, Ed.

    1998-01-01

    This theme issue of the journal "Exploring" covers the topic of "memories" and describes an exhibition at San Francisco's Exploratorium that ran from May 22, 1998 through January 1999 and that contained over 40 hands-on exhibits, demonstrations, artworks, images, sounds, smells, and tastes that demonstrated and depicted the biological,…

  4. Flash Platform Examination

    Science.gov (United States)

    2011-03-01

    Reine (en droit du Canada), telle que représentée par le ministre de la Défense nationale, 2011 DRDC Atlantic TM 2008-291 i Abstract...concepts de l’interface utilisateur novateurs. Les applications Flash de diverses fidélités peut intégrer des fonctions de visualisation des données...diverses peuvent intégrer des fonctions de visualisation des données, d’interactivité novatrice, d’animation riche et de diverses

  5. Novel Molecular Non-Volatile Memory: Application of Redox-Active Molecules

    Directory of Open Access Journals (Sweden)

    Hao Zhu

    2015-12-01

    Full Text Available This review briefly describes the development of molecular electronics in the application of non-volatile memory. Molecules, especially redox-active molecules, have become interesting due to their intrinsic redox behavior, which provides an excellent basis for low-power, high-density and high-reliability non-volatile memory applications. Recently, solid-state non-volatile memory devices based on redox-active molecules have been reported, exhibiting fast speed, low operation voltage, excellent endurance and multi-bit storage, outperforming the conventional floating-gate flash memory. Such high performance molecular memory will lead to promising on-chip memory and future portable/wearable electronics applications.

  6. Nonvolatile and Cryogenic-Compatible Quantum Memory Devices (QuMEM)

    Science.gov (United States)

    2016-06-01

    11 3.1 COMPLIMENTARY METAL-OXIDE- SEMICONDUCTOR (CMOS)......................... 11 3.2 RAPID- SINGLE -FLUX QUANTUM (RSFQ...in the plasma treatment . Section 6 explains the electrical characterization of these devices. 41 Table 5. Al/AlOx/Al device process flow. Step ...collection and storage of all data each clock cycle (generated by a single gigahertz ADC) approaches petabyte scale each day

  7. Impact of device size and thickness of Al2O3 film on the Cu pillar and resistive switching characteristics for 3D cross-point memory application

    Science.gov (United States)

    Panja, Rajeswar; Roy, Sourav; Jana, Debanjan; Maikap, Siddheswar

    2014-12-01

    Impact of the device size and thickness of Al2O3 film on the Cu pillars and resistive switching memory characteristics of the Al/Cu/Al2O3/TiN structures have been investigated for the first time. The memory device size and thickness of Al2O3 of 18 nm are observed by transmission electron microscope image. The 20-nm-thick Al2O3 films have been used for the Cu pillar formation (i.e., stronger Cu filaments) in the Al/Cu/Al2O3/TiN structures, which can be used for three-dimensional (3D) cross-point architecture as reported previously Nanoscale Res. Lett.9:366, 2014. Fifty randomly picked devices with sizes ranging from 8 × 8 to 0.4 × 0.4 μm2 have been measured. The 8-μm devices show 100% yield of Cu pillars, whereas only 74% successful is observed for the 0.4-μm devices, because smaller size devices have higher Joule heating effect and larger size devices show long read endurance of 105 cycles at a high read voltage of -1.5 V. On the other hand, the resistive switching memory characteristics of the 0.4-μm devices with a 2-nm-thick Al2O3 film show superior as compared to those of both the larger device sizes and thicker (10 nm) Al2O3 film, owing to higher Cu diffusion rate for the larger size and thicker Al2O3 film. In consequence, higher device-to-device uniformity of 88% and lower average RESET current of approximately 328 μA are observed for the 0.4-μm devices with a 2-nm-thick Al2O3 film. Data retention capability of our memory device of >48 h makes it a promising one for future nanoscale nonvolatile application. This conductive bridging resistive random access memory (CBRAM) device is forming free at a current compliance (CC) of 30 μA (even at a lowest CC of 0.1 μA) and operation voltage of ±3 V at a high resistance ratio of >104.

  8. Flash X-ray

    International Nuclear Information System (INIS)

    Sato, Eiichi

    2003-01-01

    Generation of quasi-monochromatic X-ray by production of weakly ionized line plasma (flash X-ray), high-speed imaging by the X-ray and high-contrast imaging by the characteristic X-ray absorption are described. The equipment for the X-ray is consisted from the high-voltage power supply and condenser, turbo molecular pump, and plasma X-ray tube. The tube has a long linear anticathode to produce the line plasma and flash X-ray at 20 kA current at maximum. X-ray spectrum is measured by the imaging plate equipped in the computed radiography system after diffracted by a LiF single crystal bender. Cu anticathode generates sharp peaks of K X-ray series. The tissue images are presented for vertebra, rabbit ear and heart, and dog heart by X-ray fluoroscopy with Ce anticathode. Generation of K-orbit characteristic X-ray with extremely low bremsstrahung is to be attempted for medical use. (N.I.)

  9. Stress-optimised shape memory devices for the use in microvalves

    International Nuclear Information System (INIS)

    Skrobanek, K.D.; Kohl, M.; Miyazaki, S.

    1997-01-01

    A gas valve of 6 x 6 x 2 mm 3 size has been developed for high pressure applications. Stress-optimised shape memory microbeams of 100 μm thickness are used to control the deflection of a membrane above a valve chamber. The shape memory thin sheets have been fabricated by melting and rolling, which creates specific textures. Investigations by X-ray diffraction revealed major orientations of [111] and [011] in rolling direction. The corresponding maximum anisotropy of transformation strain was 20%. The microbeams have been fabricated by laser cutting. For stress-optimisation, the lateral widths of the beams are designed for homogeneous stress distributions along the beam surfaces allowing an optimised use of the shape memory effect and a minimisation of fatigue effects. For actuation, a rhombohedral phase transformation is used. This allows operation below pressure differences of 1200 hPa in designs with one valve chamber and below 4500 hPa in pressure-compensated designs with a second valve chamber above the membrane. Maximum gas flows of 1600 seem (seem cm 2 at standart conditions/minute) and work outputs of 35 μNm are achieved for a driving power of 210 mW. The response times for closing the valves vary between 0.5 and 1.2 s and for opening between 1 and 2 s depending on the applied pressure difference. (orig.)

  10. All-polymer bistable resistive memory device based on nanoscale phase-separated PCBM-ferroelectric blends

    KAUST Repository

    Khan, Yasser

    2012-11-21

    All polymer nonvolatile bistable memory devices are fabricated from blends of ferroelectric poly(vinylidenefluoride-trifluoroethylene (P(VDF-TrFE)) and n-type semiconducting [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). The nanoscale phase separated films consist of PCBM domains that extend from bottom to top electrode, surrounded by a ferroelectric P(VDF-TrFE) matrix. Highly conducting poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) polymer electrodes are used to engineer band offsets at the interfaces. The devices display resistive switching behavior due to modulation of this injection barrier. With careful optimization of the solvent and processing conditions, it is possible to spin cast very smooth blend films (Rrms ≈ 7.94 nm) and with good reproducibility. The devices exhibit high Ion/I off ratios (≈3 × 103), low read voltages (≈5 V), excellent dielectric response at high frequencies (Ïμr ≈ 8.3 at 1 MHz), and excellent retention characteristics up to 10 000 s. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. The impact of tunnel oxide nitridation to reliability performance of charge storage non-volatile memory devices.

    Science.gov (United States)

    Lee, Meng Chuan; Wong, Hin Yong

    2014-02-01

    This paper is written to review the development of critical research on the overall impact of tunnel oxide nitridation (TON) with the aim to mitigate reliability issues due to incessant technology scaling of charge storage NVM devices. For more than 30 years, charge storage non-volatile memory (NVM) has been critical in the evolution of intelligent electronic devices and continuous development of integrated technologies. Technology scaling is the primary strategy implemented throughout the semiconductor industry to increase NVM density and drive down average cost per bit. In this paper, critical reliability challenges and key innovative technical mitigation methods are reviewed. TON is one of the major candidates to replace conventional oxide layer for its superior quality and reliability performance. Major advantages and caveats of key TON process techniques are discussed. The impact of TON on quality and reliability performance of charge storage NVM devices is carefully reviewed with emphasis on major advantages and drawbacks of top and bottom nitridation. Physical mechanisms attributed to charge retention and V(t) instability phenomenon are also reviewed in this paper.

  12. Homo-junction ferroelectric field-effect-transistor memory device using solution-processed lithium-doped zinc oxide thin films

    KAUST Repository

    Nayak, Pradipta K.

    2012-06-22

    High performance homo-junction field-effect transistor memory devices were prepared using solution processed transparent lithium-doped zinc oxide thin films for both the ferroelectric and semiconducting active layers. A highest field-effect mobility of 8.7 cm2/Vs was obtained along with an Ion/Ioff ratio of 106. The ferroelectric thin filmtransistors showed a low sub-threshold swing value of 0.19 V/dec and a significantly reduced device operating voltage (±4 V) compared to the reported hetero-junction ferroelectrictransistors, which is very promising for low-power non-volatile memory applications.

  13. Nanoscale observations of the operational failure for phase-change-type nonvolatile memory devices using Ge2Sb2Te5 chalcogenide thin films

    International Nuclear Information System (INIS)

    Yoon, Sung-Min; Choi, Kyu-Jeong; Lee, Nam-Yeal; Lee, Seung-Yun; Park, Young-Sam; Yu, Byoung-Gon

    2007-01-01

    In this study, a phase-change memory device was fabricated and the origin of device failure mode was examined using transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). Ge 2 Sb 2 Te 5 (GST) was used as the active phase-change material in the memory device and the active pore size was designed to be 0.5 μm. After the programming signals of more than 2x10 6 cycles were repeatedly applied to the device, the high-resistance memory state (reset) could not be rewritten and the cell resistance was fixed at the low-resistance state (set). Based on TEM and EDS studies, Sb excess and Ge deficiency in the device operating region had a strong effect on device reliability, especially under endurance-demanding conditions. An abnormal segregation and oxidation of Ge also was observed in the region between the device operating and inactive peripheral regions. To guarantee an data endurability of more than 1x10 10 cycles of PRAM, it is very important to develop phase-change materials with more stable compositions and to reduce the current required for programming

  14. DESTINY: A Comprehensive Tool with 3D and Multi-Level Cell Memory Modeling Capability

    Directory of Open Access Journals (Sweden)

    Sparsh Mittal

    2017-09-01

    Full Text Available To enable the design of large capacity memory structures, novel memory technologies such as non-volatile memory (NVM and novel fabrication approaches, e.g., 3D stacking and multi-level cell (MLC design have been explored. The existing modeling tools, however, cover only a few memory technologies, technology nodes and fabrication approaches. We present DESTINY, a tool for modeling 2D/3D memories designed using SRAM, resistive RAM (ReRAM, spin transfer torque RAM (STT-RAM, phase change RAM (PCM and embedded DRAM (eDRAM and 2D memories designed using spin orbit torque RAM (SOT-RAM, domain wall memory (DWM and Flash memory. In addition to single-level cell (SLC designs for all of these memories, DESTINY also supports modeling MLC designs for NVMs. We have extensively validated DESTINY against commercial and research prototypes of these memories. DESTINY is very useful for performing design-space exploration across several dimensions, such as optimizing for a target (e.g., latency, area or energy-delay product for a given memory technology, choosing the suitable memory technology or fabrication method (i.e., 2D v/s 3D for a given optimization target, etc. We believe that DESTINY will boost studies of next-generation memory architectures used in systems ranging from mobile devices to extreme-scale supercomputers. The latest source-code of DESTINY is available from the following git repository: https://bitbucket.org/sparshmittal/destinyv2.

  15. Role of Al2O3 thin layer on improving the resistive switching properties of Ta5Si3-based conductive bridge random accesses memory device

    Science.gov (United States)

    Kumar, Dayanand; Aluguri, Rakesh; Chand, Umesh; Tseng, Tseung-Yuen

    2018-04-01

    Ta5Si3-based conductive bridge random access memory (CBRAM) devices have been investigated to improve their resistive switching characteristics for their application in future nonvolatile memory technology. Changes in the switching characteristics by the addition of a thin Al2O3 layer of different thicknesses at the bottom electrode interface of a Ta5Si3-based CBRAM devices have been studied. The double-layer device with a 1 nm Al2O3 layer has shown improved resistive switching characteristics over the single layer one with a high on/off resistance ratio of 102, high endurance of more than 104 cycles, and good retention for more than 105 s at the temperature of 130 °C. The higher thermal conductivity of Al2O3 over Ta5Si3 has been attributed to the enhanced switching properties of the double-layer devices.

  16. Highly uniform and reliable resistive switching characteristics of a Ni/WOx/p+-Si memory device

    Science.gov (United States)

    Kim, Tae-Hyeon; Kim, Sungjun; Kim, Hyungjin; Kim, Min-Hwi; Bang, Suhyun; Cho, Seongjae; Park, Byung-Gook

    2018-02-01

    In this paper, we investigate the resistive switching behavior of a bipolar resistive random-access memory (RRAM) in a Ni/WOx/p+-Si RRAM with CMOS compatibility. Highly unifrom and reliable bipolar resistive switching characteristics are observed by a DC voltage sweeping and its switching mechanism can be explained by SCLC model. As a result, the possibility of metal-insulator-silicon (MIS) structural WOx-based RRAM's application to Si-based 1D (diode)-1R (RRAM) or 1T (transistor)-1R (RRAM) structure is demonstrated.

  17. Fabrication of Pb (Zr, Ti) O3 Thin Film for Non-Volatile Memory Device Application

    International Nuclear Information System (INIS)

    Mar Lar Win

    2011-12-01

    Ferroelectric lead zirconate titanate powder was composed of mainly the oxides of titanium, zirconium and lead. PZT powder was firstly prepared by thermal synthesis at different Zr/Ti ratios with various sintering temperatures. PZT thin film was fabricated on SiO2/Si substrate by using thermal evaporation method. Physical and elemental analysis were carried out by using SEM, EDX and XRD The ferroelectric properties and the switching behaviour of the PZT thin films were investigated. The ferroelectric properties and switching properties of the PZT thin film (near morphotropic phase boundary sintered at 800 C) could function as a nonvolatile memory.

  18. System of common usage on the base of external memory devices and the SM-3 computer

    International Nuclear Information System (INIS)

    Baluka, G.; Vasin, A.Yu.; Ermakov, V.A.; Zhukov, G.P.; Zimin, G.N.; Namsraj, Yu.; Ostrovnoj, A.I.; Savvateev, A.S.; Salamatin, I.M.; Yanovskij, G.Ya.

    1980-01-01

    An easily modified system of common usage on the base of external memories and a SM-3 minicomputer replacing some pulse analysers is described. The system has merits of PA and is more advantageous with regard to effectiveness of equipment using, the possibility of changing configuration and functions, the data protection against losses due to user errors and some failures, price of one registration channel, place occupied. The system of common usage is intended for the IBR-2 pulse reactor computing centre. It is designed using the SANPO system means for SM-3 computer [ru

  19. A simple method to treat an ingrowing toenail with a shape-memory alloy device.

    Science.gov (United States)

    Ishibashi, Masaya; Tabata, Nobuko; Suetake, Takaki; Omori, Toshihiro; Sutou, Yuji; Kainuma, Ryosuke; Yamauchi, Kiyoshi; Ishida, Kiyohito

    2008-01-01

    An ingrowing toenail has no definitive treatment. Previously, effective methods were complicated but easy ones had less effect. We show both an easy and an effective way with Cu-Al-Mn-based shape-memory alloys (SMAs). They have a characteristic shape which patients themselves can detach easily without any pain. But they also have enough corrective force. Cu-based SMAs cost much less than Ni-Ti-based alloys. Despite not being appropriate for all cases of ingrowing toenails, it is an easy, effective and less costly alternative.

  20. High-pressure deuterium annealing for improving the reliability characteristics of silicon-oxide-nitride-oxide-silicon nonvolatile memory devices

    Science.gov (United States)

    Choi, Sangmoo; Jang, Man; Park, Hokyung; Hwang, Hyunsang; Jeon, Sanghun; Kim, Juhyung; Kim, Chungwoo

    2004-12-01

    We report the effects of high-pressure deuterium postmetallization annealing on the reliability characteristics of silicon-oxide-nitride-oxide-silicon nonvolatile memory devices. Compared with the control samples annealed in a conventional forming gas ambient (H2/N2=4%/96%), the samples annealed in a high-pressure (10 atm) pure deuterium ambient show improved endurance and retention characteristics without the degradation of program/erase (P/E) speed. In addition, the high-pressure deuterium-annealed samples show a significantly reduced charge loss rate for the electron-stored state and the hole-stored state, before and after the P/E cycles. The improved reliability of the high-pressure deuterium-annealed samples can be explained by the significantly decreased interface trap density and the large kinetic isotope effect of deuterium, which reduces the generation of the interface trap density under the stress of the P/E cycles.

  1. Two-channel recoder for magnetometer with energy-independent mass memory device

    International Nuclear Information System (INIS)

    Korzinin, V.N.; Selivanov, A.M.

    1993-01-01

    The paper describes a two-channel digit-to-analog recorder designed for converting the sequence of pulses from proton magnetometer (MMH-203) outlet; the device enables processing of the pulses and their recording in RAM and on the tape of the analog recorder. The availability of nonvolotile RAM allows to transmit digit information to a computer (BK-0010) for its further processing

  2. Shape-memory alloy overload protection device for osseointegrated transfemoral implant prosthetic limb attachment system

    Science.gov (United States)

    Xu, Wei; Shao, Fei; Hughes, Steven

    2002-11-01

    The osseointegrated trans-femoral implant system provides a direct anchoring technique to attach prosthetic limb. This technique was first introduced PI Brenmark in Sweden. The UK had the first clinical trial in 1997 and currently has 6 active limb wearers. The success of this procedure has the potential for improved gait function and mobility, increased employability and significant long-term improvements in the quality of life for above knee amputees. However, the significant load involved in the trans-femoral implant system has caused permanent deformation and/or fractures of the implant abutment in several occasions. To protect the implant system, the implant abutment in particularly, an overloading protection device was introduced. The device uses mechanical mechanism to release torsion overload on the abutment. However, the bending overload protection remains unsolved. To solve the problem, a new overload protection device was developed. This device uses SMA component for bending overload protection. In this paper, the results of non-linear finite element modelling of the SMA and steel (AISI 1040) components were presented. Experiments were also carried out using steel components to assess the design which is based on the non-linear property of the materials.

  3. The role of inelastic deformations in the mechanical response of endovascular shape memory alloy devices.

    Science.gov (United States)

    Petrini, Lorenza; Bertini, Alessandro; Berti, Francesca; Pennati, Giancarlo; Migliavacca, Francesco

    2017-05-01

    Nickel-titanium alloys are commonly adopted for producing cardiovascular minimally invasive devices such as self-expandable stents, aortic valves and stent-grafts. These devices are subjected to cyclic loads (due to blood pulsatility, leg or heart movements), that can induce fatigue fracture, and may also be subjected to very large deformations (due to crimping procedure, a tortuous physiological path or overloads), that can induce material yield. Recently, the authors developed a new constitutive model that considers inelastic strains due to not-completed reverse phase transformation (not all the stress-induced martensite turns back to austenite) or/and plasticity and their accumulation during cyclic loads. In this article, the model is implemented in the finite element code ABAQUS/Standard and it is used to investigate the effects of inelastic strain accumulation on endovascular nickel-titanium devices. In particular, the behavior of a transcatheter aortic valve is studied considering the following steps: (1) crimping, (2) expansion in a tube resembling a durability test chamber and (3) cyclic loads due to pressure variation applied on the inner surface of the tube. The analyses are performed twice, activating and not activating that part of the new model which describes the development of irreversible strain. From the results, it is interesting to note that plasticity has a very significant effect on the local material response, inducing stress modification from compression to tension. However, permanent deformations are concentrated in few zones of the stent frame and their presence does not affect the global behavior of the device that maintains its capability of recovering the original shape. In conclusion, this work suggests that at least for cardiovascular devices where the crimping is high (local strain may reach values of 8%-9%), taking into account inelastic effects due to plasticity and not-completed reverse phase transformation can be important, and

  4. Size-tunable synthesis of monolayer MoS2 nanoparticles and their applications in non-volatile memory devices.

    Science.gov (United States)

    Jeon, Jaeho; Lee, Jinhee; Yoo, Gwangwe; Park, Jin-Hong; Yeom, Geun Young; Jang, Yun Hee; Lee, Sungjoo

    2016-09-29

    We report the CVD synthesis of a monolayer of MoS 2 nanoparticles such that the nanoparticle size was controlled over the range 5-100 nm and the chemical potential of sulfur was modified, both by controlling the hydrogen flow rate during the CVD process. As the hydrogen flow rate was increased, the reaction process of sulfur changed from a "sulfiding" process to a "sulfo-reductive" process, resulting in the growth of smaller MoS 2 nanoparticles on the substrates. The size control, crystalline quality, chemical configuration, and distribution uniformity of the CVD-grown monolayer MoS 2 nanoparticles were confirmed. The growth of the MoS 2 nanoparticles at different edge states was studied using density functional theory calculations to clarify the size-tunable mechanism. A non-volatile memory device fabricated using the CVD-grown size-controlled 5 nm monolayer MoS 2 nanoparticles as a floating gate showed a good memory window of 5-8 V and an excellent retention period of a decade.

  5. Shape memory effect of nano-ferromagnetic particle doped NiTi for orthopedic devices and rehabilitation techniques.

    Science.gov (United States)

    Gautam, Arvind; Balouria, Anuradha; Acharyya, Amit; Acharyya, Swati Ghosh; Panwar, Madhuri; Naik, Ganesh R

    2017-07-01

    This paper introduces a novel shape memory alloy (SMA) material for the controllability in the shape recovery of traditional SMA for orthopedic devices and rehabilitation techniques. The proposed material is formed by doping nano-ferromagnetic particle into porous NiTi alloy. The finite element analysis of shape memory effect property of the different distribution of nano-ferromagnetic particle is done and compared for same load and boundary conditions. The comparative analysis of the percentage change in volume deformation when load is released (for 2 nd step) shows an average of 2.55 % with standard deviation of 1.69 whereas on thermal loading (for 3 rd step) shows an average of 94.94% with standard deviation of 7.75 for all heterogeneous distribution of nano-particles in porous NiTi alloy. Our findings are, all the different conditions of heterogeneous distributions of nano-ferromagnetic particle doped NiTi alloy exhibits its inherent SME property.

  6. Crystal that remembers: several ways to utilize nanocrystals in resistive switching memory

    Science.gov (United States)

    Banerjee, Writam; Liu, Qi; Long, Shibing; Lv, Hangbing; Liu, Ming

    2017-08-01

    The attractive usability of quantum phenomena in futuristic devices is possible by using zero-dimensional systems like nanocrystals (NCs). The performance of nonvolatile flash memory devices has greatly benefited from the use of NCs over recent decades. The quantum abilities of NCs have been used to improve the reliability of flash devices. Its appeal is extended to the design of emerging devices such as resistive random-access memory (RRAM), a technology where the use of silicon is optional. Here, we are going to review the recent progress in the design, characterization, and utilization of NCs in RRAM devices. We will first introduce the physical design of the RRAM devices using NCs and the improvement of electrical performance in NC-RRAM over conventional ones. In particular, special care has been taken to review the ways of development provided by the NCs in the RRAM devices. In a broad sense, the NCs can play a charge trapping role in the NC-RRAM structure or it can be responsible for the localization and improvement of the stability of the conductive filament or it can play a part in the formation of the conductive filament chain by the NC migration under applied bias. Finally, the scope of NCs in the RRAM devices has also been discussed.

  7. Crystal that remembers: several ways to utilize nanocrystals in resistive switching memory

    International Nuclear Information System (INIS)

    Banerjee, Writam; Liu, Qi; Long, Shibing; Lv, Hangbing; Liu, Ming

    2017-01-01

    The attractive usability of quantum phenomena in futuristic devices is possible by using zero-dimensional systems like nanocrystals (NCs). The performance of nonvolatile flash memory devices has greatly benefited from the use of NCs over recent decades. The quantum abilities of NCs have been used to improve the reliability of flash devices. Its appeal is extended to the design of emerging devices such as resistive random-access memory (RRAM), a technology where the use of silicon is optional. Here, we are going to review the recent progress in the design, characterization, and utilization of NCs in RRAM devices. We will first introduce the physical design of the RRAM devices using NCs and the improvement of electrical performance in NC-RRAM over conventional ones. In particular, special care has been taken to review the ways of development provided by the NCs in the RRAM devices. In a broad sense, the NCs can play a charge trapping role in the NC-RRAM structure or it can be responsible for the localization and improvement of the stability of the conductive filament or it can play a part in the formation of the conductive filament chain by the NC migration under applied bias. Finally, the scope of NCs in the RRAM devices has also been discussed. (topical review)

  8. The dominant factors affecting the memory characteristics of (Ta2O5)x(Al2O3)1-x high-k charge-trapping devices

    Science.gov (United States)

    Gong, Changjie; Yin, Qiaonan; Ou, Xin; Lan, Xuexin; Liu, Jinqiu; Sun, Chong; Wang, Laiguo; Lu, Wei; Yin, Jiang; Xu, Bo; Xia, Yidong; Liu, Zhiguo; Li, Aidong

    2014-09-01

    The prototypical charge-trapping memory devices with the structure p-Si/Al2O3/(Ta2O5)x(Al2O3)1-x/Al2O3/Pt(x = 0.5, 0.3, and 0.1) were fabricated by using atomic layer deposition and RF magnetron sputtering techniques. A memory window of 7.39 V with a charge storage density of 1.97 × 1013 cm-2 at a gate voltage of ±11 V was obtained for the memory device with the composite charge trapping layer (Ta2O5)0.5(Al2O3)0.5. All memory devices show fast program/erase speed and excellent endurance and retention properties, although some differences in their memory performance exist, which was ascribed to the relative individual band alignments of the composite (Ta2O5)x(Al2O3)1-x with Si.

  9. Realization of write-once-read-many-times memory device with O2 plasma-treated indium gallium zinc oxide thin film

    International Nuclear Information System (INIS)

    Liu, P.; Chen, T. P.; Li, X. D.; Wong, J. I.; Liu, Z.; Liu, Y.; Leong, K. C.

    2014-01-01

    A write-once-read-many-times (WORM) memory devices based on O 2 plasma-treated indium gallium zinc oxide (IGZO) thin films has been demonstrated. The device has a simple Al/IGZO/Al structure. The device has a normally OFF state with a very high resistance (e.g., the resistance at 2 V is ∼10 9 Ω for a device with the radius of 50 μm) as a result of the O 2 plasma treatment on the IGZO thin films. The device could be switched to an ON state with a low resistance (e.g., the resistance at 2 V is ∼10 3 Ω for the radius of 50 μm) by applying a voltage pulse (e.g., 10 V/1 μs). The WORM device has good data-retention and reading-endurance capabilities

  10. Flashing coupled density wave oscillation

    International Nuclear Information System (INIS)

    Jiang Shengyao; Wu Xinxin; Zhang Youjie

    1997-07-01

    The experiment was performed on the test loop (HRTL-5), which simulates the geometry and system design of the 5 MW reactor. The phenomenon and mechanism of different kinds of two-phase flow instabilities, namely geyser instability, flashing instability and flashing coupled density wave instability are described. The especially interpreted flashing coupled density wave instability has never been studied well, it is analyzed by using a one-dimensional non-thermo equilibrium two-phase flow drift model computer code. Calculations are in good agreement with the experiment results. (5 refs.,5 figs., 1 tab.)

  11. Multistate storage nonvolatile memory device based on ferroelectricity and resistive switching effects of SrBi2Ta2O9 films

    Science.gov (United States)

    Song, Zhiwei; Li, Gang; Xiong, Ying; Cheng, Chuanpin; Zhang, Wanli; Tang, Minghua; Li, Zheng; He, Jiangheng

    2018-05-01

    A memory device with a Pt/SrBi2Ta2O9(SBT)/Pt(111) structure was shown to have excellent combined ferroelectricity and resistive switching properties, leading to higher multistate storage memory capacity in contrast to ferroelectric memory devices. In this device, SBT polycrystalline thin films with significant (115) orientation were fabricated on Pt(111)/Ti/SiO2/Si(100) substrates using CVD (chemical vapor deposition) method. Measurement results of the electric properties exhibit reproducible and reliable ferroelectricity switching behavior and bipolar resistive switching effects (BRS) without an electroforming process. The ON/OFF ratio of the resistive switching was found to be about 103. Switching mechanisms for the low resistance state (LRS) and high resistance state (HRS) currents are likely attributed to the Ohmic and space charge-limited current (SCLC) behavior, respectively. Moreover, the ferroelectricity and resistive switching effects were found to be mutually independent, and the four logic states were obtained by controlling the periodic sweeping voltage. This work holds great promise for nonvolatile multistate memory devices with high capacity and low cost.

  12. Low-temperature LPCVD of Si nanocrystals from disilane and trisilane (Silcore®) embedded in ALD-alumina for non-volatile memory devices

    NARCIS (Netherlands)

    Brunets, I.; Aarnink, Antonius A.I.; Boogaard, A.; Kovalgin, Alexeij Y.; Wolters, Robertus A.M.; Holleman, J.; Schmitz, Jurriaan

    Non-volatile memory devices are realized using CVD and ALD of all active layers in a cluster tool. The floating gate consists of silicon nanocrystals. A high nanocrystal density was obtained through an enhanced nucleation rate by using disilane (Si2H6) as well as trisilane (Si3H8, known as Silcore®)

  13. Microwave-Assisted Size Control of Colloidal Nickel Nanocrystals for Colloidal Nanocrystals-Based Non-volatile Memory Devices

    Science.gov (United States)

    Yadav, Manoj; Velampati, Ravi Shankar R.; Mandal, D.; Sharma, Rohit

    2018-03-01

    Colloidal synthesis and size control of nickel (Ni) nanocrystals (NCs) below 10 nm are reported using a microwave synthesis method. The synthesised colloidal NCs have been characterized using x-ray diffraction, transmission electron microscopy (TEM) and dynamic light scattering (DLS). XRD analysis highlights the face centred cubic crystal structure of synthesised NCs. The size of NCs observed using TEM and DLS have a distribution between 2.6 nm and 10 nm. Furthermore, atomic force microscopy analysis of spin-coated NCs over a silicon dioxide surface has been carried out to identify an optimum spin condition that can be used for the fabrication of a metal oxide semiconductor (MOS) non-volatile memory (NVM) capacitor. Subsequently, the fabrication of a MOS NVM capacitor is reported to demonstrate the potential application of colloidal synthesized Ni NCs in NVM devices. We also report the capacitance-voltage (C-V) and capacitance-time (C-t) response of the fabricated MOS NVM capacitor. The C-V and C-t characteristics depict a large flat band voltage shift (V FB) and high retention time, respectively, which indicate that colloidal Ni NCs are excellent candidates for applications in next-generation NVM devices.

  14. A memory efficient implementation scheme of Gauss error function in a Laguerre-Volterra network for neuroprosthetic devices

    Science.gov (United States)

    Li, Will X. Y.; Cui, Ke; Zhang, Wei

    2017-04-01

    Cognitive neural prosthesis is a manmade device which can be used to restore or compensate for lost human cognitive modalities. The generalized Laguerre-Volterra (GLV) network serves as a robust mathematical underpinning for the development of such prosthetic instrument. In this paper, a hardware implementation scheme of Gauss error function for the GLV network targeting reconfigurable platforms is reported. Numerical approximations are formulated which transform the computation of nonelementary function into combinational operations of elementary functions, and memory-intensive look-up table (LUT) based approaches can therefore be circumvented. The computational precision can be made adjustable with the utilization of an error compensation scheme, which is proposed based on the experimental observation of the mathematical characteristics of the error trajectory. The precision can be further customizable by exploiting the run-time characteristics of the reconfigurable system. Compared to the polynomial expansion based implementation scheme, the utilization of slice LUTs, occupied slices, and DSP48E1s on a Xilinx XC6VLX240T field-programmable gate array has decreased by 94.2%, 94.1%, and 90.0%, respectively. While compared to the look-up table based scheme, 1.0 ×1017 bits of storage can be spared under the maximum allowable error of 1.0 ×10-3 . The proposed implementation scheme can be employed in the study of large-scale neural ensemble activity and in the design and development of neural prosthetic device.

  15. Progress of application, research and development, and design guidelines for shape memory alloy devices for cultural heritage structures in Italy

    Science.gov (United States)

    Castellano, Maria G.; Indirli, Maurizio; Martelli, Alessandro

    2001-07-01

    A wide ranging R&D Project (ISTECH) on validation and application of the Innovative Antiseismic Techniques (IATs) for the restoration of Cultural Heritage Structures (CUHESs), especially masonry buildings, based on the Shape Memory Alloys (SMAs), has been funded by the European Commission (EC), in the framework of the Environment and Climate RTD Programme. Because Traditional Restoration Techniques (TRTs) have sometimes proved inadequate in avoiding collapses and often too invasive, the use of superelastic SMA Devices (SMADs) has been developed. Theoretical and numerical studies, as well as intensive testing of material specimens, devices, structural models and in situ campaigns, show that SMADs can substantially increase the stability of masonry CUHESs exposed to an earthquake. Different SMAD types have been investigated to fulfil different structural needs and they can be custom designed taking into account each monument's characteristics. The successful results of the research and its exploitation led to important applications in Italy: the S. Giorgio Church Bell-Tower, located at Trignano, S. Martino in Rio, Reggio Emilia, damaged by the 15th October 1996 earthquake, the transept tympana of the S. Francesco Basilica in Assisi and the S. Feliciano Cathedral façade in Foligno, both heavily damaged by the September 1997 earthquake. In addition, further studies and applications of SMAD technology are foreseen in Italy in the next future, in the framework of Italian and European research projects and proposals.

  16. A memory efficient implementation scheme of Gauss error function in a Laguerre-Volterra network for neuroprosthetic devices.

    Science.gov (United States)

    Li, Will X Y; Cui, Ke; Zhang, Wei

    2017-04-01

    Cognitive neural prosthesis is a manmade device which can be used to restore or compensate for lost human cognitive modalities. The generalized Laguerre-Volterra (GLV) network serves as a robust mathematical underpinning for the development of such prosthetic instrument. In this paper, a hardware implementation scheme of Gauss error function for the GLV network targeting reconfigurable platforms is reported. Numerical approximations are formulated which transform the computation of nonelementary function into combinational operations of elementary functions, and memory-intensive look-up table (LUT) based approaches can therefore be circumvented. The computational precision can be made adjustable with the utilization of an error compensation scheme, which is proposed based on the experimental observation of the mathematical characteristics of the error trajectory. The precision can be further customizable by exploiting the run-time characteristics of the reconfigurable system. Compared to the polynomial expansion based implementation scheme, the utilization of slice LUTs, occupied slices, and DSP48E1s on a Xilinx XC6VLX240T field-programmable gate array has decreased by 94.2%, 94.1%, and 90.0%, respectively. While compared to the look-up table based scheme, 1.0×10 17 bits of storage can be spared under the maximum allowable error of 1.0×10 -3 . The proposed implementation scheme can be employed in the study of large-scale neural ensemble activity and in the design and development of neural prosthetic device.

  17. A numerical analysis and experimental demonstration of a low degradation conductive bridge resistive memory device

    KAUST Repository

    Berco, Dan

    2017-10-23

    This study investigates a low degradation metal-ion conductive bridge RAM (CBRAM) structure. The structure is based on placing a diffusion blocking layer (DBL) between the device\\'s top electrode (TE) and the resistive switching layer (RSL), unlike conventional CBRAMs, where the TE serves as a supply reservoir for metallic species diffusing into the RSL to form a conductive filament (CF) and is kept in direct contact with the RSL. The properties of a conventional CBRAM structure (Cu/HfO2/TiN), having a Cu TE, 10 nm HfO2 RSL, and a TiN bottom electrode, are compared with a 2 nm TaN DBL incorporating structure (Cu/TaN/HfO2/TiN) for 103 programming and erase simulation cycles. The low and high resistive state values for each cycle are calculated and the analysis reveals that adding the DBL yields lower degradation. In addition, the 2D distribution plots of oxygen vacancies, O ions, and Cu species within the RSL indicate that oxidation occurring in the DBL-RSL interface results in the formation of a sub-stoichiometric tantalum oxynitride with higher blocking capabilities that suppresses further Cu insertion beyond an initial CF formation phase, as well as CF lateral widening during cycling. The higher endurance of the structure with DBL may thus be attributed to the relatively low amount of Cu migrating into the RSL during the initial CF formation. Furthermore, this isomorphic CF displays similar cycling behavior to neural ionic channels. The results of numerical analysis show a good match to experimental measurements of similar device structures as well

  18. Compact Modeling Solutions for Oxide-Based Resistive Switching Memories (OxRAM

    Directory of Open Access Journals (Sweden)

    Marc Bocquet

    2014-01-01

    Full Text Available Emerging non-volatile memories based on resistive switching mechanisms attract intense R&D efforts from both academia and industry. Oxide-based Resistive Random Acces Memories (OxRAM gather noteworthy performances, such as fast write/read speed, low power and high endurance outperforming therefore conventional Flash memories. To fully explore new design concepts such as distributed memory in logic, OxRAM compact models have to be developed and implemented into electrical simulators to assess performances at a circuit level. In this paper, we present compact models of the bipolar OxRAM memory based on physical phenomenons. This model was implemented in electrical simulators for single device up to circuit level.

  19. Mechanical behaviour of umbrella-shaped, Ni-Ti memory alloy femoral head support device during implant operation: a finite element analysis study.

    Directory of Open Access Journals (Sweden)

    Wei Yi

    Full Text Available A new instrument used for treating femoral head osteonecrosis was recently proposed: the umbrella-shaped, Ni-Ti memory femoral head support device. The device has an efficacy rate of 82.35%. Traditional radiographic study provides limited information about the mechanical behaviour of the support device during an implant operation. Thus, this study proposes a finite element analysis method, which includes a 3-step formal head model construction scheme and a unique material assignment strategy for evaluating mechanical behaviour during an implant operation. Four different scenarios with different constraints, initial positions and bone qualities are analyzed using the simulation method. The max radium of the implanted device was consistent with observation data, which confirms the accuracy of the proposed method. To ensure that the device does not unexpectedly open and puncture the femoral head, the constraint on the impact device should be strong. The initial position of sleeve should be in the middle to reduce the damage to the decompression channel. The operation may fail because of poor bone quality caused by severe osteoporosis. The proposed finite element analysis method has proven to be an accurate tool for studying the mechanical behaviour of umbrella-shaped, Ni-Ti memory alloy femoral head support device during an implant operation. The 3-step construct scheme can be implemented with any kind of bone structure meshed with multiple element types.

  20. Compliant liquid column damper modified by shape memory alloy device for seismic vibration control

    International Nuclear Information System (INIS)

    Gur, Sourav; Mishra, Sudib Kumar; Bhowmick, Sutanu; Chakraborty, Subrata

    2014-01-01

    Liquid column dampers (LCDs) have long been used for the seismic vibration control of flexible structures. In contrast, tuning LCDs to short-period structures poses difficulty. Various modifications have been proposed on the original LCD configuration for improving its performance in relatively stiff structures. One such system, referred to as a compliant-LCD has been proposed recently by connecting the LCD to the structure with a spring. In this study, an improvement is attempted in compliant LCDs by replacing the linear spring with a spring made of shape memory alloy (SMA). Considering the dissipative, super-elastic, force-deformation hysteresis of SMA triggered by stress-induced micro-structural phase transition, the performance is expected to improve further. The optimum parameters for the SMA-compliant LCD are obtained through design optimization, which is based on a nonlinear random vibration response analysis via stochastic linearization of the force-deformation hysteresis of SMA and dissipation by liquid motion through an orifice. Substantially enhanced performance of the SMA–LCD over a conventional compliant LCD is demonstrated, the consistency of which is further verified under recorded ground motions. The robustness of the improved performance is also validated by parametric study concerning the anticipated variations in system parameters as well as variability in seismic loading. (paper)

  1. Corrosion testing in flash tanks

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, S.J.; Stead, N.J.

    1999-07-01

    As kraft pulp mills adopt modified cooking processes, an increasing amount of corrosion of carbon steel digester systems is being encountered. Many mills have had severe corrosion in the flash tanks, in particular, the first ({number{underscore}sign}1) flash tank. The work described in this report was aimed at characterizing the corrosion. Coupons of carbon steel, several stainless steels and titanium were exposed at two mills. At mill A, identical sets of coupons were exposed in the {number{underscore}sign}1 and {number{underscore}sign}2 flash tank. At mill B, three identical sets of coupons were placed in flash tank {number{underscore}sign}1. The results of the exposures showed that both carbon steel and titanium suffered high rates of general corrosion, while the stainless steels suffered varying degrees of localized attack. The ranking of the resistance of corrosion in the flash tank was the same ranking as would be expected in a reducing acid environment. In the light of the coupon results, organic acids is concluded to be the most likely cause of corrosion of the flash tanks.

  2. A numerical analysis and experimental demonstration of a low degradation conductive bridge resistive memory device

    Science.gov (United States)

    Berco, Dan; Chand, Umesh; Fariborzi, Hossein

    2017-10-01

    This study investigates a low degradation metal-ion conductive bridge RAM (CBRAM) structure. The structure is based on placing a diffusion blocking layer (DBL) between the device's top electrode (TE) and the resistive switching layer (RSL), unlike conventional CBRAMs, where the TE serves as a supply reservoir for metallic species diffusing into the RSL to form a conductive filament (CF) and is kept in direct contact with the RSL. The properties of a conventional CBRAM structure (Cu/HfO2/TiN), having a Cu TE, 10 nm HfO2 RSL, and a TiN bottom electrode, are compared with a 2 nm TaN DBL incorporating structure (Cu/TaN/HfO2/TiN) for 103 programming and erase simulation cycles. The low and high resistive state values for each cycle are calculated and the analysis reveals that adding the DBL yields lower degradation. In addition, the 2D distribution plots of oxygen vacancies, O ions, and Cu species within the RSL indicate that oxidation occurring in the DBL-RSL interface results in the formation of a sub-stoichiometric tantalum oxynitride with higher blocking capabilities that suppresses further Cu insertion beyond an initial CF formation phase, as well as CF lateral widening during cycling. The higher endurance of the structure with DBL may thus be attributed to the relatively low amount of Cu migrating into the RSL during the initial CF formation. Furthermore, this isomorphic CF displays similar cycling behavior to neural ionic channels. The results of numerical analysis show a good match to experimental measurements of similar device structures as well.

  3. Feasibility study of shape memory alloy ring spring systems for self-centring seismic resisting devices

    International Nuclear Information System (INIS)

    Fang, Cheng; Yam, Michael C H; Zhang, Yanyang; Lam, Angus C C

    2015-01-01

    Shape memory alloys (SMAs) have recently emerged as promising material candidates for structural seismic resisting purposes. Most of the existing SMA-based strategies, however, are based on the wire or rod form of SMAs, where issues such as gripping complexity and fracture may exist. This paper presents a proof-of-concept study on an innovative type of SMA-based self-centring system, namely, a superelastic SMA ring spring system. The proposed system includes a series of inner high-strength steel (HSS) rings and outer superelastic SMA rings stacked in alternation with mating taper faces, where the resisting load is provided by the wedging action which tends to expand the outer rings and concurrently to squeeze the inner rings. The superelastic effect of the SMA offers energy dissipation and a driving force for recentring, and the frictional effect over the taper face further contributes to the overall resisting load and energy dissipation. The feasibility of the new system is carefully examined via numerical studies considering the parameters of ring thickness, taper angle, and coefficient of friction. The key hysteretic responses, including resisting load, stiffness, stress distributions, source of residual deformation, energy dissipation, and equivalent viscous damping, are discussed in detail. The behaviour of the SMA ring springs is also studied via analytical models, and the analytical predictions are found to agree well with the numerical results. Finally, two practical applications of the new system, namely self-centring HS-SMA ring spring connections, and self-centring SMA ring spring dampers, are discussed via comprehensive numerical studies. (paper)

  4. Fabrication and properties of nanoscale multiferroic heterostructures for application in magneto-electric random access memory (MERAM) devices

    Science.gov (United States)

    Kim, Gunwoo

    Magnetoelectric random access memory (MERAM) has emerged as a promising new class of non-volatile solid-state memory device. It offers nondestructive reading along with low power consumption during the write operation. A common implementation of MERAM involves use of multiferroic tunneling junctions (MFTJs), which besides offering non-volatility are both electrically and magnetically tunable. Fundamentally, a MFTJ consists of a heterostructure of an ultrathin multiferroic or ferroelectric material as the active tunneling barrier sandwiched between ferromagnetic electrodes. Thereby, the MFTJ exhibits both tunnel electroresistance (TER) and tunnel magnetoresistance (TMR) effects with application of an electric and magnetic field, respectively. In this thesis work, we have developed two-dimensional (2D) thin-film multiferroic heterostructure METJ prototypes consisting of ultrathin ferroelectric BaTiO3 (BTO) layer and a conducting ferromagnetic La0.67Sr 0.33MnO3 (LSMO) electrode. The heteroepitaxial films are grown using the pulsed laser deposition (PLD) technique. This oxide heterostructure offers the opportunity to study the nano-scale details of the tunnel electroresistance (TER) effect using scanning probe microscopy techniques. We performed the measurements using the MFP-3D (Asylum Research) scanning probe microscope. The ultrathin BTO films (1.2-2.0 nm) grown on LSMO electrodes display both ferro- and piezo-electric properties and exhibit large tunnel resistance effect. We have explored the growth and properties of one-dimensional (1D) heterostructures, referred to as multiferoric nanowire (NW) heterostructures. The ferromagnetic/ferroelectric composite heterostructures are grown as sheath layers using PLD on lattice-matched template NWs, e.g. MgO, that are deposited by chemical vapor deposition utilizing the vapor-liquid-solid (VLS) mechanism. The one-dimensional geometry can substantially overcome the clamping effect of the substrate present in two

  5. In Situ Transmission Electron Microscopy Observation of Nanostructural Changes in Phase-Change Memory

    KAUST Repository

    Meister, Stefan

    2011-04-26

    Phase-change memory (PCM) has been researched extensively as a promising alternative to flash memory. Important studies have focused on its scalability, switching speed, endurance, and new materials. Still, reliability issues and inconsistent switching in PCM devices motivate the need to further study its fundamental properties. However, many investigations treat PCM cells as black boxes; nanostructural changes inside the devices remain hidden. Here, using in situ transmission electron microscopy, we observe real-time nanostructural changes in lateral Ge2Sb2Te5 (GST) PCM bridges during switching. We find that PCM devices with similar resistances can exhibit distinct threshold switching behaviors due to the different initial distribution of nanocrystalline and amorphous domains, explaining variability of switching behaviors of PCM cells in the literature. Our findings show a direct correlation between nanostructure and switching behavior, providing important guidelines in the design and operation of future PCM devices with improved endurance and lower variability. © 2011 American Chemical Society.

  6. Conducting atomic force microscopy studies on doped CulnO2 thin films for resistive memory device applications

    International Nuclear Information System (INIS)

    Mehta, B.R.

    2009-01-01

    Full text: Delafosite thin films have interesting structural, optical and electronic properties due to the highly anisotropic crystal structure and possibility of bipolar conductivity. In this presentation, optical, structural and electrical properties of Sn (n type) and Ca (p type) doped CulnO 2 layers grown by rf magnetron sputtering technique will be discussed. Depending on doping and deposition temperature, these films show nanocolumnar structure with (110) and (006) preferred orientations. The observed decrease in activation energy from 0.9 eV to about 0.10 eV and a large decrease in conductivity from 2.11 x 10 -10 Scm -1 to 1.66 x 10 -1 Scm -1 on Sn doping has been explained due to the change in preferred orientation along with efficient doping. Our results show that crystallite orientation is the most important factor controlling the electrical conduction in delafossite thin films. The anisotropy of electrical conduction along (006) and (110) directions in tin doped samples has been further established using conducting atomic force microscopy (CAFM) measurements. The CAFM measurements shows the presence of nanoconducting region when the current flow direction is aligned along the BO 6 layer and complete absence of conducting regions when the current direction is perpendicular to the film surface. Resistive memory devices based on Sn and Ca doped CulnO 2 films show stable and reproducible 'on' and 'off' states. CAFM measurement on these devices carried out before and after 'forming' show the growth of nanoconducting filaments on the application of a threshold voltage. It is possible to control resistance in the 'on' and 'off' states and magnitude of the forming and switching voltages by controlling the doping concentration and crystallite orientation in CulnO 2 layers

  7. Quick-low-density parity check and dynamic threshold voltage optimization in 1X nm triple-level cell NAND flash memory with comprehensive analysis of endurance, retention-time, and temperature variation

    Science.gov (United States)

    Doi, Masafumi; Tokutomi, Tsukasa; Hachiya, Shogo; Kobayashi, Atsuro; Tanakamaru, Shuhei; Ning, Sheyang; Ogura Iwasaki, Tomoko; Takeuchi, Ken

    2016-08-01

    NAND flash memory’s reliability degrades with increasing endurance, retention-time and/or temperature. After a comprehensive evaluation of 1X nm triple-level cell (TLC) NAND flash, two highly reliable techniques are proposed. The first proposal, quick low-density parity check (Quick-LDPC), requires only one cell read in order to accurately estimate a bit-error rate (BER) that includes the effects of temperature, write and erase (W/E) cycles and retention-time. As a result, 83% read latency reduction is achieved compared to conventional AEP-LDPC. Also, W/E cycling is extended by 100% compared with conventional Bose-Chaudhuri-Hocquenghem (BCH) error-correcting code (ECC). The second proposal, dynamic threshold voltage optimization (DVO) has two parts, adaptive V Ref shift (AVS) and V TH space control (VSC). AVS reduces read error and latency by adaptively optimizing the reference voltage (V Ref) based on temperature, W/E cycles and retention-time. AVS stores the optimal V Ref’s in a table in order to enable one cell read. VSC further improves AVS by optimizing the voltage margins between V TH states. DVO reduces BER by 80%.

  8. Integration of optically active Neodymium ions in Niobium devices (Nd:Nb): quantum memory for hybrid quantum entangled systems

    Science.gov (United States)

    Nayfeh, O. M.; Chao, D.; Djapic, N.; Sims, P.; Liu, B.; Sharma, S.; Lerum, L.; Fahem, M.; Dinh, V.; Zlatanovic, S.; Lynn, B.; Torres, C.; Higa, B.; Moore, J.; Upchurch, A.; Cothern, J.; Tukeman, M.; Barua, R.; Davidson, B.; Ramirez, A. D.; Rees, C. D.; Anant, V.; Kanter, G. S.

    2017-08-01

    Optically active rare-earth Neodymium (Nd) ions are integrated in Niobium (Nb) thin films forming a new quantum memory device (Nd:Nb) targeting long-lived coherence times and multi-functionality enabled by both spin and photon storage properties. Nb is implanted with Nd spanning 10-60 keV energy and 1013-1014 cm-2 dose producing a 1- 3% Nd:Nb concentration as confirmed by energy-dispersive X-ray spectroscopy. Scanning confocal photoluminescence (PL) at 785 nm excitation are made and sharp emission peaks from the 4F3/2 -red shift and increased broadening to a 4.8 nm linewidth. Nd:Nb is photoconductive and responds strongly to applied fields. Furthermore, optically detected magnetic resonance (ODMR) measurements are presented spanning near-infrared telecom band. The modulation of the emission intensity with magnetic field and microwave power by integration of these magnetic Kramer type Nd ions is quantified along with spin echoes under pulsed microwave π-π/2 excitation. A hybrid system architecture is proposed using spin and photon quantum information storage with the nuclear and electron states of the Nd3+ and neighboring Nb atoms that can couple qubit states to hyperfine 7/2 spin states of Nd:Nb and onto NIR optical levels excitable with entangled single photons, thus enabling implementation of computing and networking/internet protocols in a single platform.

  9. Demo-application of shape memory alloy devices: the rehabilitation of the S. Giorgio Church bell tower

    Science.gov (United States)

    Indirli, Maurizio; Castellano, Maria G.; Clemente, Paolo; Martelli, Alessandro

    2001-07-01

    This paper describes the rehabilitation of the S. Giorgio Church Bell-Tower (Trignano, Municipality of S. Martino in Rio, Reggio Emilia, Italy), completed in September 1999. This masonry building, seriously damaged by the earthquake of October 15th 1996 which struck the Reggio Emilia and Modena Districts, Italy), was investigated by the authors immediately after the seismic event, as other ancient Cultural Heritage Structures (CUHESs) in the same area. In the past, seismic events have visited substantial destruction that translates into a significant loss of architectural heritage. The most common solution traditionally used to enhance the CUHESs seismic behaviour is the introduction of localized reinforcements, usually Traditional Steel Ties (TSTs), increasing stability and ductility. Anyway, in many cases said reinforcement techniques, often too invasive, proved to be inadequate to prevent collapse. For these reasons, the Bell-Tower intervention applies Innovative Antiseismic Techniques (IATs) by the use of superelastic Shape Memory Alloy (SMA) Devices (SMADs), a technology developed after a large amount of theoretical studies, numerical analyses and test campaigns. The SMADs, which can be considered a powerful tool with respect to the traditional methods, provide acceleration reduction, force limitation and energy dissipation. Furthermore, they are characterized by low invasivity and complete reversibility. When another earthquake occurred on June 18th 2000, with the same epicenter and a comparable Richter Magnitudo, the Bell-Tower, subjected to a new investigation, showed no damage of any type. Thus, the new seismic event has been the best verification of the retrofit intervention.

  10. Characterization of an Autonomous Non-Volatile Ferroelectric Memory Latch

    Science.gov (United States)

    John, Caroline S.; MacLeod, Todd C.; Evans, Joe; Ho, Fat D.

    2011-01-01

    We present the electrical characterization of an autonomous non-volatile ferroelectric memory latch using the principle that when an electric field is applied to a ferroelectriccapacitor,the positive and negative remnant polarization charge states of the capacitor are denoted as either data 0 or data 1. The properties of the ferroelectric material to store an electric polarization in the absence of an electric field make the device non-volatile. Further the memory latch is autonomous as it operates with the ground, power and output node connections, without any externally clocked control line. The unique quality of this latch circuit is that it can be written when powered off. The advantages of this latch over flash memories are: a) It offers unlimited reads/writes b) works on symmetrical read/write cycles. c) The latch is asynchronous. The circuit was initially developed by Radiant Technologies Inc., Albuquerque, New Mexico.

  11. Multiferroic Memories

    Directory of Open Access Journals (Sweden)

    Amritendu Roy

    2012-01-01

    Full Text Available Multiferroism implies simultaneous presence of more than one ferroic characteristics such as coexistence of ferroelectric and magnetic ordering. This phenomenon has led to the development of various kinds of materials and conceptions of many novel applications such as development of a memory device utilizing the multifunctionality of the multiferroic materials leading to a multistate memory device with electrical writing and nondestructive magnetic reading operations. Though, interdependence of electrical- and magnetic-order parameters makes it difficult to accomplish the above and thus rendering the device to only two switchable states, recent research has shown that such problems can be circumvented by novel device designs such as formation of tunnel junction or by use of exchange bias. In this paper, we review the operational aspects of multiferroic memories as well as the materials used for these applications along with the designs that hold promise for the future memory devices.

  12. Production of bio-oil with flash pyrolysis; Biooeljyn tuotanto flash-pyrolyysillae ja sen poltto

    Energy Technology Data Exchange (ETDEWEB)

    Nyroenen, T. [Vapo Oy, Jyvaeskylae (Finland)

    1997-12-01

    The target of the R and D work is to study the production of bio-oils using Flash-pyrolysis technology and utilisation of the bio-oil in oil-fuelled boilers. The PDU-unit was installed at VTT Energy in Otaniemi in April 1996. The first test were carried out in June. In the whole project Vapo Oy is responsible for: acquiring the 20 kg/h PDU-device for development; follow up of the engine tests; the investment of 5 MW demonstration plant; to carry on the boiler and engine tests with Finnish bio-oils. (orig.)

  13. Material insights of HfO2-based integrated 1-transistor-1-resistor resistive random access memory devices processed by batch atomic layer deposition.

    Science.gov (United States)

    Niu, Gang; Kim, Hee-Dong; Roelofs, Robin; Perez, Eduardo; Schubert, Markus Andreas; Zaumseil, Peter; Costina, Ioan; Wenger, Christian

    2016-06-17

    With the continuous scaling of resistive random access memory (RRAM) devices, in-depth understanding of the physical mechanism and the material issues, particularly by directly studying integrated cells, become more and more important to further improve the device performances. In this work, HfO2-based integrated 1-transistor-1-resistor (1T1R) RRAM devices were processed in a standard 0.25 μm complementary-metal-oxide-semiconductor (CMOS) process line, using a batch atomic layer deposition (ALD) tool, which is particularly designed for mass production. We demonstrate a systematic study on TiN/Ti/HfO2/TiN/Si RRAM devices to correlate key material factors (nano-crystallites and carbon impurities) with the filament type resistive switching (RS) behaviours. The augmentation of the nano-crystallites density in the film increases the forming voltage of devices and its variation. Carbon residues in HfO2 films turn out to be an even more significant factor strongly impacting the RS behaviour. A relatively higher deposition temperature of 300 °C dramatically reduces the residual carbon concentration, thus leading to enhanced RS performances of devices, including lower power consumption, better endurance and higher reliability. Such thorough understanding on physical mechanism of RS and the correlation between material and device performances will facilitate the realization of high density and reliable embedded RRAM devices with low power consumption.

  14. Material insights of HfO2-based integrated 1-transistor-1-resistor resistive random access memory devices processed by batch atomic layer deposition

    Science.gov (United States)

    Niu, Gang; Kim, Hee-Dong; Roelofs, Robin; Perez, Eduardo; Schubert, Markus Andreas; Zaumseil, Peter; Costina, Ioan; Wenger, Christian

    2016-06-01

    With the continuous scaling of resistive random access memory (RRAM) devices, in-depth understanding of the physical mechanism and the material issues, particularly by directly studying integrated cells, become more and more important to further improve the device performances. In this work, HfO2-based integrated 1-transistor-1-resistor (1T1R) RRAM devices were processed in a standard 0.25 μm complementary-metal-oxide-semiconductor (CMOS) process line, using a batch atomic layer deposition (ALD) tool, which is particularly designed for mass production. We demonstrate a systematic study on TiN/Ti/HfO2/TiN/Si RRAM devices to correlate key material factors (nano-crystallites and carbon impurities) with the filament type resistive switching (RS) behaviours. The augmentation of the nano-crystallites density in the film increases the forming voltage of devices and its variation. Carbon residues in HfO2 films turn out to be an even more significant factor strongly impacting the RS behaviour. A relatively higher deposition temperature of 300 °C dramatically reduces the residual carbon concentration, thus leading to enhanced RS performances of devices, including lower power consumption, better endurance and higher reliability. Such thorough understanding on physical mechanism of RS and the correlation between material and device performances will facilitate the realization of high density and reliable embedded RRAM devices with low power consumption.

  15. Flashing light in microalgae biotechnology.

    Science.gov (United States)

    Abu-Ghosh, Said; Fixler, Dror; Dubinsky, Zvy; Iluz, David

    2016-03-01

    Flashing light can enhance photosynthesis and improve the quality and quantity of microalgal biomass, as it can increase the products of interest by magnitudes. Therefore, the integration of flashing light effect into microalgal cultivation systems should be considered. However, microalgae require a balanced mix of the light/dark cycle for higher growth rates, and respond to light intensity differently according to the pigments acquired or lost during the growth. This review highlights recently published results on flashing light effect on microalgae and its applications in biotechnology, as well as the recently developed bioreactors designed to fulfill this effect. It also discusses how this knowledge can be applied in selecting the optimal light frequencies and intensities with specific technical properties for increasing biomass production and/or the yield of the chemicals of interest by microalgae belonging to different genera. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Non-volatile resistive memory device fabricated from CdSe quantum dot embedded in thermally grown In2O3 nanostructure by oblique angle deposition

    Science.gov (United States)

    Kannan, V.; Kim, Hyun-Seok; Park, Hyun-Chang

    2016-11-01

    In this paper we report In2O3/CdSe quantum dot based non-volatile resistive memory device with ON/OFF ratio ∼1000. Indium nanostructures were grown by oblique angle deposition technique in a thermal evaporator. Indium oxide nanostructures had size ranging from 20 nm to 100 nm as observed from TEM and AFM methods. The facile device fabricated with a layer of CdSe quantum dot on indium oxide film exhibited excellent endurance characteristics over 100,000 switching cycles. Retention tests showed good stability for over 4000 s. Memory operating mechanism is proposed based on charge trapping/de-trapping in quantum dots with indium oxide acting as barrier leading to Coulomb blockade. The mechanism is supported by negative differential resistance (NDR) observed exclusively in the ON state.

  17. A two-terminal write-once-read-many-times-memory device based on an aluminum nitride thin film containing Al nanocrystals.

    Science.gov (United States)

    Liu, Y; Chen, T P; Ding, L; Li, Y B; Zhang, S; Fung, S

    2010-09-01

    A switching from a high-conduction state to a low-conduction state occurs in an AIN thin film containing Al nanocrystals (nc-Al) when the nc-Al is charged with electrons. The switching is explained in terms of breaking of the conductive percolation paths of the nc-AI as a result of the charging of the nc-Al. A write-once-read many times-memory (WORM) device is demonstrated based on this phenomenon. The device can be switched by charging the nc-Al with a voltage of +10 V for 100 ms, yielding a current ratio of the two memory states of more than 300 at the reading voltage of 1 V. The charged state (i.e., the low-conduction state) remains unchanged after more than 1 x 106 read cycles, and its retention time is predicted to be more than 10 years.

  18. Realization of synaptic learning and memory functions in Y2O3 based memristive device fabricated by dual ion beam sputtering

    Science.gov (United States)

    Das, Mangal; Kumar, Amitesh; Singh, Rohit; Than Htay, Myo; Mukherjee, Shaibal

    2018-02-01

    Single synaptic device with inherent learning and memory functions is demonstrated based on a forming-free amorphous Y2O3 (yttria) memristor fabricated by dual ion beam sputtering system. Synaptic functions such as nonlinear transmission characteristics, long-term plasticity, short-term plasticity and ‘learning behavior (LB)’ are achieved using a single synaptic device based on cost-effective metal-insulator-semiconductor (MIS) structure. An ‘LB’ function is demonstrated, for the first time in the literature, for a yttria based memristor, which bears a resemblance to certain memory functions of biological systems. The realization of key synaptic functions in a cost-effective MIS structure would promote much cheaper synapse for artificial neural network.

  19. Synaptic plasticity and memory functions achieved in a WO3−x-based nanoionics device by using the principle of atomic switch operation

    International Nuclear Information System (INIS)

    Yang, Rui; Terabe, Kazuya; Yao, Yiping; Tsuruoka, Tohru; Hasegawa, Tsuyoshi; Gimzewski, James K; Aono, Masakazu

    2013-01-01

    A compact neuromorphic nanodevice with inherent learning and memory properties emulating those of biological synapses is the key to developing artificial neural networks rivaling their biological counterparts. Experimental results showed that memorization with a wide time scale from volatile to permanent can be achieved in a WO 3−x -based nanoionics device and can be precisely and cumulatively controlled by adjusting the device’s resistance state and input pulse parameters such as the amplitude, interval, and number. This control is analogous to biological synaptic plasticity including short-term plasticity, long-term potentiation, transition from short-term memory to long-term memory, forgetting processes for short- and long-term memory, learning speed, and learning history. A compact WO 3−x -based nanoionics device with a simple stacked layer structure should thus be a promising candidate for use as an inorganic synapse in artificial neural networks due to its striking resemblance to the biological synapse. (paper)

  20. Quick Guide to Flash Catalyst

    CERN Document Server

    Elmansy, Rafiq

    2011-01-01

    How do you transform user interface designs created in Photoshop or Illustrator into interactive web pages? It's easier than you think. This guide shows you how to use Adobe Flash Catalyst to create interactive UIs and website wireframes for Rich Internet Applications-without writing a single line of code. Ideal for web designers, this book introduces Flash Catalyst basics with detailed step-by-step instructions and screenshots that illustrate every part of the process. You'll learn hands-on how to turn your static design or artwork into working user interfaces that can be implemented in Fla

  1. A supramolecular approach on using poly(fluorenylstyrene)-block-poly(2-vinylpyridine):PCBM composite thin films for non-volatile memory device applications.

    Science.gov (United States)

    Hsu, Jung-Ching; Liu, Cheng-Liang; Chen, Wen-Chang; Sugiyama, Kenji; Hirao, Akira

    2011-03-16

    Supramolecular composite thin films of poly[4-(9,9-dihexylfloren-2-yl)styrene]-block-poly(2-vinylpyridine) (P(St-Fl)-b-P2VP):[6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) were prepared for write-once-read-many times (WORM) non-volatile memory devices. The optical absorption and photoluminescence results indicated the formation of charge transfer complexation between the P2VP block and PCBM, which led to the varied PCBM aggregated size and memory characteristics. The ITO/PCBM:(P(St-Fl)-b-P2VP)/Al device exhibited the WORM characteristic with low threshold voltage (-1.6 to -3.2 V) and high ON/OFF ratio (10(3) to 10(5)) by tuning the PCBM content. The switching behavior could be explained by the charge injection dominated thermionic emission in the OFF state and field-induced charge transfer in the ON state. The present study provides a novel approach system for tuning polymer memory device characteristics through the supramolecular materials approach. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Enhanced oxygen vacancy diffusion in Ta{sub 2}O{sub 5} resistive memory devices due to infinitely adaptive crystal structure

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Hao [San Jose Research Center, HGST, a Western Digital company, San Jose, California 95135 (United States); Materials Science Program, University of Wisconsin, Madison, Wisconsin 53706 (United States); Stewart, Derek A., E-mail: derek.stewart@hgst.com [San Jose Research Center, HGST, a Western Digital company, San Jose, California 95135 (United States)

    2016-04-07

    Metal oxide resistive memory devices based on Ta{sub 2}O{sub 5} have demonstrated high switching speed, long endurance, and low set voltage. However, the physical origin of this improved performance is still unclear. Ta{sub 2}O{sub 5} is an important archetype of a class of materials that possess an adaptive crystal structure that can respond easily to the presence of defects. Using first principles nudged elastic band calculations, we show that this adaptive crystal structure leads to low energy barriers for in-plane diffusion of oxygen vacancies in λ phase Ta{sub 2}O{sub 5}. Identified diffusion paths are associated with collective motion of neighboring atoms. The overall vacancy diffusion is anisotropic with higher diffusion barriers found for oxygen vacancy movement between Ta-O planes. Coupled with the fact that oxygen vacancy formation energy in Ta{sub 2}O{sub 5} is relatively small, our calculated low diffusion barriers can help explain the low set voltage in Ta{sub 2}O{sub 5} based resistive memory devices. Our work shows that other oxides with adaptive crystal structures could serve as potential candidates for resistive random access memory devices. We also discuss some general characteristics for ideal resistive RAM oxides that could be used in future computational material searches.

  3. A Novel Dual Traffic/Flash Flood Monitoring System Using Passive Infrared/Ultrasonic Sensors

    KAUST Repository

    Mousa, Mustafa

    2015-10-19

    Floods are the most common type of natural disaster, causing thousands of casualties every year. Among these events, urban flash floods are particularly deadly because of the short timescales on which they occur, and because of the high concentration of population in cities. Since most flash flood casualties are caused by a lack of information, it is critical to generate accurate and detailed warnings of flash floods. However, deploying an infrastructure that solely monitor flash floods makes little economic sense, since the average periodicity of catastrophic flash floods exceeds the lifetime of a typical sensor network. To address this issue, we propose a new sensing device that can simultaneously monitor urban flash floods and another phenomenon of interest (traffic congestion on the present case). This sensing device is based on the combination of an ultrasonic rangefinder with one or multiple remote temperature sensors. We show an implementation of this device, and illustrate its performance in both traffic flow and flash flood sensing. Field data shows that the sensor can detect vehicles with a 99% accuracy, in addition to estimating their speed and classifying them in function of their length. The same sensor can also monitor urban water levels with an accuracy of less than 2 cm. Two of the sensors have been deployed in a flood prone area, where they captured the only (minor) flash flood that occurred over the one-year test period, with no false detection, and an agreement in the estimated water level estimate (during the flash flood event) of about 2 cm.

  4. A pilot study of magnetic therapy for hot flashes after breast cancer.

    Science.gov (United States)

    Carpenter, Janet S; Wells, Nancy; Lambert, Beth; Watson, Peggy; Slayton, Tami; Chak, Bapsi; Hepworth, Joseph T; Worthington, W Bradley

    2002-04-01

    The purpose of this randomized placebo-controlled crossover pilot study was to evaluate the effectiveness and acceptability of magnetic therapy for hot flashes among breast cancer survivors. Participants completed a 24-hour baseline hot-flash monitoring session, wore the magnetic devices or placebo for 3 days, completed an after-treatment hot-flash monitoring session, experienced a 10-day washout period, and then crossed over to the opposite study arm. Magnetic devices and placebos were placed on 6 acupressure sites corresponding to hot-flash relief. Complete data were available from 11 survivors of breast cancer. Results indicated magnetic therapy was no more effective than placebo in decreasing hot-flash severity, and contrary to expectations, placebo was significantly more effective than magnets in decreasing hot-flash frequency, bother, interference with daily activities, and overall quality of life. Implications for clinical practice and future research include the need to explore alternative interventions aimed at alleviating hot flashes in this population.

  5. MBE-grown Si and Si(1-x)Ge(x) quantum dots embedded within epitaxial Gd2O3 on Si(111) substrate for floating gate memory device.

    Science.gov (United States)

    Manna, S; Aluguri, R; Katiyar, A; Das, S; Laha, A; Osten, H J; Ray, S K

    2013-12-20

    Si and Si(1-x)Ge(x) quantum dots embedded within epitaxial Gd2O3 grown by molecular beam epitaxy have been studied for application in floating gate memory devices. The effect of interface traps and the role of quantum dots on the memory properties have been studied using frequency-dependent capacitance-voltage and conductance-voltage measurements. Multilayer quantum dot memory comprising four and five layers of Si quantum dots exhibits a superior memory window to that of single-layer quantum dot memory devices. It has also been observed that single-layer Si(1-x)Ge(x) quantum dots show better memory characteristics than single-layer Si quantum dots.

  6. Hot Flashes amd Night Sweats (PDQ)

    Science.gov (United States)

    ... controlled with estrogen replacement therapy. Hot flashes during natural or treatment-related menopause can be controlled with estrogen replacement ... been studied in the treatment of hot flashes. Treatments that help patients cope with stress and anxiety may help manage hot flashes. Treatments ...

  7. Detection of Malicious Flash Banner Advertisements

    Directory of Open Access Journals (Sweden)

    Kirill Alekseevich Samosadnyy

    2014-09-01

    Full Text Available The paper addresses the problem of detecting malicious flash advertisements. As a result, detection method based on dynamic analysis that modify flash application and execute it in Adobe Flash player is proposed and evaluated on synthetic and real world examples.

  8. Flash CS4: The Missing Manual

    CERN Document Server

    Grover, Chris

    2008-01-01

    Unlock the power of Flash and bring gorgeous animations to life onscreen. Flash CS4: The Missing Manual includes a complete primer on animation, a guided tour of the program's tools and capabilities, lots of new illustrations, and more details on working with video. Beginners will learn to use the software in no time, and experienced Flash designers will improve their skills.

  9. Jaan Toomik ajakirjas Flash Art

    Index Scriptorium Estoniae

    1999-01-01

    Kunstiajakirja "Flash Art" maikuu numbris Ando Keskküla artikkel, mis annab ülevaate J. Toomiku loomingust ja peatub pikemalt tema olulisematel töödel. 10. juunist J. Toomiku isiknäitus Londoni fotograafide galeriis. Eksponeeritud video "Uisutaja"

  10. Ingmar Muusikuse foto Flash Artis

    Index Scriptorium Estoniae

    1999-01-01

    Flash Arti 1999. a. oktoobrinumbris virtuaalse näituse rubriigis Ando Keskküla artikkel radikaalsemast eesti kunstist ja kunstielust postsotsialistlikul ajastul. Illustratsiooniks Liina Siibi fotokompositsioonid, Ingmar Muusikuse foto Raoul Kurvitza, Ene-Liis Semperi ja Kiwa Eesti Panga performance'ist

  11. Low-cost fabrication and polar-dependent switching uniformity of memory devices using alumina interfacial layer and Ag nanoparticle monolayer

    Directory of Open Access Journals (Sweden)

    Peng Xia

    2017-11-01

    Full Text Available A facile and low-cost process was developed for fabricating write-once-read-many-times (WORM Cu/Ag NPs/Alumina/Al memory devices, where the alumina passivation layer formed naturally in air at room temperature, whereas the Ag nanoparticle monolayer was in situ prepared through thermal annealing of a 4.5 nm Ag film in air at 150°C. The devices exhibit irreversible transition from initial high resistance (OFF state to low resistance (ON state, with ON/OFF ratio of 107, indicating the introduction of Ag nanoparticle monolayer greatly improves ON/OFF ratio by four orders of magnitude. The uniformity of threshold voltages exhibits a polar-dependent behavior, and a narrow range of threshold voltages of 0.40 V among individual devices was achieved upon the forward voltage. The memory device can be regarded as two switching units connected in series. The uniform alumina interfacial layer and the non-uniform distribution of local electric fields originated from Ag nanoparticles might be responsible for excellent switching uniformity. Since silver ions in active layer can act as fast ion conductor, a plausible mechanism relating to the formation of filaments sequentially among the two switching units connected in series is suggested for the polar-dependent switching behavior. Furthermore, we demonstrate both alumina layer and Ag NPs monolayer play essential roles in improving switching parameters based on comparative experiments.

  12. Low-cost fabrication and polar-dependent switching uniformity of memory devices using alumina interfacial layer and Ag nanoparticle monolayer

    Science.gov (United States)

    Xia, Peng; Li, Luman; Wang, Pengfei; Gan, Ying; Xu, Wei

    2017-11-01

    A facile and low-cost process was developed for fabricating write-once-read-many-times (WORM) Cu/Ag NPs/Alumina/Al memory devices, where the alumina passivation layer formed naturally in air at room temperature, whereas the Ag nanoparticle monolayer was in situ prepared through thermal annealing of a 4.5 nm Ag film in air at 150°C. The devices exhibit irreversible transition from initial high resistance (OFF) state to low resistance (ON) state, with ON/OFF ratio of 107, indicating the introduction of Ag nanoparticle monolayer greatly improves ON/OFF ratio by four orders of magnitude. The uniformity of threshold voltages exhibits a polar-dependent behavior, and a narrow range of threshold voltages of 0.40 V among individual devices was achieved upon the forward voltage. The memory device can be regarded as two switching units connected in series. The uniform alumina interfacial layer and the non-uniform distribution of local electric fields originated from Ag nanoparticles might be responsible for excellent switching uniformity. Since silver ions in active layer can act as fast ion conductor, a plausible mechanism relating to the formation of filaments sequentially among the two switching units connected in series is suggested for the polar-dependent switching behavior. Furthermore, we demonstrate both alumina layer and Ag NPs monolayer play essential roles in improving switching parameters based on comparative experiments.

  13. Interfacial phase-change memory.

    Science.gov (United States)

    Simpson, R E; Fons, P; Kolobov, A V; Fukaya, T; Krbal, M; Yagi, T; Tominaga, J

    2011-07-03

    Phase-change memory technology relies on the electrical and optical properties of certain materials changing substantially when the atomic structure of the material is altered by heating or some other excitation process. For example, switching the composite Ge(2)Sb(2)Te(5) (GST) alloy from its covalently bonded amorphous phase to its resonantly bonded metastable cubic crystalline phase decreases the resistivity by three orders of magnitude, and also increases reflectivity across the visible spectrum. Moreover, phase-change memory based on GST is scalable, and is therefore a candidate to replace Flash memory for non-volatile data storage applications. The energy needed to switch between the two phases depends on the intrinsic properties of the phase-change material and the device architecture; this energy is usually supplied by laser or electrical pulses. The switching energy for GST can be reduced by limiting the movement of the atoms to a single dimension, thus substantially reducing the entropic losses associated with the phase-change process. In particular, aligning the c-axis of a hexagonal Sb(2)Te(3) layer and the 〈111〉 direction of a cubic GeTe layer in a superlattice structure creates a material in which Ge atoms can switch between octahedral sites and lower-coordination sites at the interface of the superlattice layers. Here we demonstrate GeTe/Sb(2)Te(3) interfacial phase-change memory (IPCM) data storage devices with reduced switching energies, improved write-erase cycle lifetimes and faster switching speeds.

  14. 49 CFR 221.13 - Marking device display.

    Science.gov (United States)

    2010-10-01

    ... functioning photoelectric cell activation mechanism shall illuminate or flash the device continuously when... flash a marking device prescribed in this subpart. (b) Unless equipped with a functioning photoelectric cell activation mechanism complying with paragraph (c) of this section, the marking devices prescribed...

  15. Speeding up the flash calculations in two-phase compositional flow simulations - The application of sparse grids

    KAUST Repository

    Wu, Yuanqing

    2015-03-01

    Flash calculations have become a performance bottleneck in the simulation of compositional flow in subsurface reservoirs. We apply a sparse grid surrogate model to substitute the flash calculation and thus try to remove the bottleneck from the reservoir simulation. So instead of doing a flash calculation in each time step of the simulation, we just generate a sparse grid approximation of all possible results of the flash calculation before the reservoir simulation. Then we evaluate the constructed surrogate model to approximate the values of the flash calculation results from this surrogate during the simulations. The execution of the true flash calculation has been shifted from the online phase during the simulation to the offline phase before the simulation. Sparse grids are known to require only few unknowns in order to obtain good approximation qualities. In conjunction with local adaptivity, sparse grids ensure that the accuracy of the surrogate is acceptable while keeping the memory usage small by only storing a minimal amount of values for the surrogate. The accuracy of the sparse grid surrogate during the reservoir simulation is compared to the accuracy of using a surrogate based on regular Cartesian grids and the original flash calculation. The surrogate model improves the speed of the flash calculations and the simulation of the whole reservoir. In an experiment, it is shown that the speed of the online flash calculations is increased by about 2000 times and as a result the speed of the reservoir simulations has been enhanced by 21 times in the best conditions.

  16. 1D versus 3D quantum confinement in 1-5 nm ZnO nanoparticle agglomerations for application in charge-trapping memory devices.

    Science.gov (United States)

    El-Atab, Nazek; Nayfeh, Ammar

    2016-07-08

    ZnO nanoparticles (NPs) have attracted considerable interest from industry and researchers due to their excellent properties with applications in optoelectronic devices, sunscreens, photocatalysts, sensors, biomedical sciences, etc. However, the agglomeration of NPs is considered to be a limiting factor since it can affect the desirable physical and electronic properties of the NPs. In this work, 1-5 nm ZnO NPs deposited by spin- and dip-coating techniques are studied. The electronic and physical properties of the resulting agglomerations of NPs are studied using UV-vis-NIR spectroscopy, atomic force microscopy (AFM), and transmission electron microscopy (TEM), and their application in metal-oxide-semiconductor (MOS) memory devices is analyzed. The results show that both dip- and spin-coating techniques lead to agglomerations of the NPs mostly in the horizontal direction. However, the width of the ZnO clusters is larger with dip-coating which leads to 1D quantum confinement, while the smaller ZnO clusters obtained by spin-coating enable 3D quantum confinement in ZnO. The ZnO NPs are used as the charge-trapping layer of a MOS-memory structure and the analysis of the high-frequency C-V measurements allow further understanding of the electronic properties of the ZnO agglomerations. A large memory window is achieved in both devices which confirms that ZnO NPs provide large charge-trapping density. In addition, ZnO confined in 3D allows for a larger memory window at lower operating voltages due to the Poole-Frenkel charge-emission mechanism.

  17. 1D versus 3D quantum confinement in 1-5 nm ZnO nanoparticle agglomerations for application in charge-trapping memory devices

    Science.gov (United States)

    El-Atab, Nazek; Nayfeh, Ammar

    2016-07-01

    ZnO nanoparticles (NPs) have attracted considerable interest from industry and researchers due to their excellent properties with applications in optoelectronic devices, sunscreens, photocatalysts, sensors, biomedical sciences, etc. However, the agglomeration of NPs is considered to be a limiting factor since it can affect the desirable physical and electronic properties of the NPs. In this work, 1-5 nm ZnO NPs deposited by spin- and dip-coating techniques are studied. The electronic and physical properties of the resulting agglomerations of NPs are studied using UV-vis-NIR spectroscopy, atomic force microscopy (AFM), and transmission electron microscopy (TEM), and their application in metal-oxide-semiconductor (MOS) memory devices is analyzed. The results show that both dip- and spin-coating techniques lead to agglomerations of the NPs mostly in the horizontal direction. However, the width of the ZnO clusters is larger with dip-coating which leads to 1D quantum confinement, while the smaller ZnO clusters obtained by spin-coating enable 3D quantum confinement in ZnO. The ZnO NPs are used as the charge-trapping layer of a MOS-memory structure and the analysis of the high-frequency C-V measurements allow further understanding of the electronic properties of the ZnO agglomerations. A large memory window is achieved in both devices which confirms that ZnO NPs provide large charge-trapping density. In addition, ZnO confined in 3D allows for a larger memory window at lower operating voltages due to the Poole-Frenkel charge-emission mechanism.

  18. Digital signal processor for silicon audio playback devices; Silicon audio saisei kikiyo digital signal processor

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    The digital audio signal processor (DSP) TC9446F series has been developed silicon audio playback devices with a memory medium of, e.g., flash memory, DVD players, and AV devices, e.g., TV sets. It corresponds to AAC (advanced audio coding) (2ch) and MP3 (MPEG1 Layer3), as the audio compressing techniques being used for transmitting music through an internet. It also corresponds to compressed types, e.g., Dolby Digital, DTS (digital theater system) and MPEG2 audio, being adopted for, e.g., DVDs. It can carry a built-in audio signal processing program, e.g., Dolby ProLogic, equalizer, sound field controlling, and 3D sound. TC9446XB has been lined up anew. It adopts an FBGA (fine pitch ball grid array) package for portable audio devices. (translated by NEDO)

  19. Development of Next Generation Memory Test Experiment for Deployment on a Small Satellite

    Science.gov (United States)

    MacLeod, Todd; Ho, Fat D.

    2012-01-01

    The original Memory Test Experiment successfully flew on the FASTSAT satellite launched in November 2010. It contained a single Ramtron 512K ferroelectric memory. The memory device went through many thousands of read/write cycles and recorded any errors that were encountered. The original mission length was schedule to last 6 months but was extended to 18 months. New opportunities exist to launch a similar satellite and considerations for a new memory test experiment should be examined. The original experiment had to be designed and integrated in less than two months, so the experiment was a simple design using readily available parts. The follow-on experiment needs to be more sophisticated and encompass more technologies. This paper lays out the considerations for the design and development of this follow-on flight memory experiment. It also details the results from the original Memory Test Experiment that flew on board FASTSAT. Some of the design considerations for the new experiment include the number and type of memory devices to be used, the kinds of tests that will be performed, other data needed to analyze the results, and best use of limited resources on a small satellite. The memory technologies that are considered are FRAM, FLASH, SONOS, Resistive Memory, Phase Change Memory, Nano-wire Memory, Magneto-resistive Memory, Standard DRAM, and Standard SRAM. The kinds of tests that could be performed are read/write operations, non-volatile memory retention, write cycle endurance, power measurements, and testing Error Detection and Correction schemes. Other data that may help analyze the results are GPS location of recorded errors, time stamp of all data recorded, radiation measurements, temperature, and other activities being perform by the satellite. The resources of power, volume, mass, temperature, processing power, and telemetry bandwidth are extremely limited on a small satellite. Design considerations must be made to allow the experiment to not interfere

  20. Multi-step resistive switching behavior of Li-doped ZnO resistance random access memory device controlled by compliance current

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chun-Cheng [Department of Electrical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Department of Mathematic and Physical Sciences, R.O.C. Air Force Academy, Kaohsiung 820, Taiwan (China); Tang, Jian-Fu; Su, Hsiu-Hsien [Department of Electrical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Hong, Cheng-Shong; Huang, Chih-Yu [Department of Electronic Engineering, National Kaohsiung Normal University, Kaohsiung 802, Taiwan (China); Chu, Sheng-Yuan, E-mail: chusy@mail.ncku.edu.tw [Department of Electrical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan (China)

    2016-06-28

    The multi-step resistive switching (RS) behavior of a unipolar Pt/Li{sub 0.06}Zn{sub 0.94}O/Pt resistive random access memory (RRAM) device is investigated. It is found that the RRAM device exhibits normal, 2-, 3-, and 4-step RESET behaviors under different compliance currents. The transport mechanism within the device is investigated by means of current-voltage curves, in-situ transmission electron microscopy, and electrochemical impedance spectroscopy. It is shown that the ion transport mechanism is dominated by Ohmic behavior under low electric fields and the Poole-Frenkel emission effect (normal RS behavior) or Li{sup +} ion diffusion (2-, 3-, and 4-step RESET behaviors) under high electric fields.

  1. Multi-step resistive switching behavior of Li-doped ZnO resistance random access memory device controlled by compliance current

    International Nuclear Information System (INIS)

    Lin, Chun-Cheng; Tang, Jian-Fu; Su, Hsiu-Hsien; Hong, Cheng-Shong; Huang, Chih-Yu; Chu, Sheng-Yuan

    2016-01-01

    The multi-step resistive switching (RS) behavior of a unipolar Pt/Li 0.06 Zn 0.94 O/Pt resistive random access memory (RRAM) device is investigated. It is found that the RRAM device exhibits normal, 2-, 3-, and 4-step RESET behaviors under different compliance currents. The transport mechanism within the device is investigated by means of current-voltage curves, in-situ transmission electron microscopy, and electrochemical impedance spectroscopy. It is shown that the ion transport mechanism is dominated by Ohmic behavior under low electric fields and the Poole-Frenkel emission effect (normal RS behavior) or Li + ion diffusion (2-, 3-, and 4-step RESET behaviors) under high electric fields.

  2. A Radiation-Tolerant, Low-Power Non-Volatile Memory Based on Silicon Nanocrystal Quantum Dots

    Science.gov (United States)

    Bell, L. D.; Boer, E. A.; Ostraat, M. L.; Brongersma, M. L.; Flagan, R. C.; Atwater, H. A.; deBlauwe, J.; Green, M. L.

    2001-01-01

    Nanocrystal nonvolatile floating-gate memories are a good candidate for space applications - initial results suggest they are fast, more reliable and consume less power than conventional floating gate memories. In the nanocrystal based NVM device, charge is not stored on a continuous polysilicon layer (so-called floating gate), but instead on a layer of discrete nanocrystals. Charge injection and storage in dense arrays of silicon nanocrystals in SiO2 is a critical aspect of the performance of potential nanocrystal flash memory structures. The ultimate goal for this class of devices is few- or single-electron storage in a small number of nanocrystal elements. In addition, the nanocrystal layer fabrication technique should be simple, 8-inch wafer compatible and well controlled in program/erase threshold voltage swing was seen during 100,000 program and erase cycles. Additional near-term goals for this project include extensive testing for radiation hardness and the development of artificial layered tunnel barrier heterostructures which have the potential for large speed enhancements for read/write of nanocrystal memory elements, compared with conventional flash devices. Additional information is contained in the original extended abstract.

  3. Foundation Flash CS4 for Designers

    CERN Document Server

    Green, Tom

    2008-01-01

    In this book, you'll learn:* How to create effective animations using the new Motion Editor and animation tools * How to use the new 3D features to animate objects in 3D space * Best-practice tips and techniques from some of the top Flash practitioners on the planet * How to create captioned video and full-screen video, and deploy HD video using Flash * Techniques for using the Flash UI components as well as XML documents to create stunning,interactive presentations If you're a Flash designer looking for a solid overview of Flash CS4, this book is for you. Through the use of solid and practica

  4. From Sulfide Flash Smelting to a Novel Flash Ironmaking Technology

    Science.gov (United States)

    Sohn, Hong Yong

    A novel flash ironmaking technology is under development at the University of Utah under the support of U.S. Department of Energy (DOE) and American Iron and Steel Institute (AISI). The history of the development from the conception of the idea to the current status will be discussed. The flash ironmaking process produces iron directly from fine iron ore concentrates without requiring cokemaking and pelletization/sintering, which will enable the technology to significantly reduce energy consumption and carbon dioxide emissions compared with blast furnace ironmaking. Unlike other gas-based ironmaking processes, this technology will not suffer from the problems of solid sticking and fusion. Current work is focused on the method of supplying the energy required to maintain the necessary temperature, as an intermediate step to determine the scalability for larger, industrial-scale pilot trials.

  5. Standardized clinical photography: the role of flash.

    Science.gov (United States)

    Cariello, Angelino; Viana, Giovanni André; Osaki, Midori; Pamplona, André Luis; Höfling-Lima, Ana Luisa

    2012-01-01

    Medical photographic documentation is important for professional, research, and ethical concerns. This study analyzed the possible interference that the flash could cause on evaluation of lower eyelid cosmetic results. Standardized photographs with and without flash were taken of 10 patients with dermatochalasis. The photographs were evaluated by 3 independent observers, as before (without flash) and after (with flash) an alternative esthetic treatment of the lower eyelid. The observers rated the overall cosmetic improvement of the lower eyelid photographs on a visual analog scale. The 3 surgeons believed that there was improvement in cosmetic outcome from the first (without flash) to the second (with flash) picture. The results indicate that a simple flash addition in one of 2 consecutive photographs, taken seconds apart, could influence the impression of experienced surgeons on the final outcome of oculoplastic surgeries and may constitute a bias in observer-dependent studies.

  6. Flexible non-volatile optical memory thin-film transistor device with over 256 distinct levels based on an organic bicomponent blend.

    Science.gov (United States)

    Leydecker, Tim; Herder, Martin; Pavlica, Egon; Bratina, Gvido; Hecht, Stefan; Orgiu, Emanuele; Samorì, Paolo

    2016-09-01

    Organic nanomaterials are attracting a great deal of interest for use in flexible electronic applications such as logic circuits, displays and solar cells. These technologies have already demonstrated good performances, but flexible organic memories are yet to deliver on all their promise in terms of volatility, operational voltage, write/erase speed, as well as the number of distinct attainable levels. Here, we report a multilevel non-volatile flexible optical memory thin-film transistor based on a blend of a reference polymer semiconductor, namely poly(3-hexylthiophene), and a photochromic diarylethene, switched with ultraviolet and green light irradiation. A three-terminal device featuring over 256 (8 bit storage) distinct current levels was fabricated, the memory states of which could be switched with 3 ns laser pulses. We also report robustness over 70 write-erase cycles and non-volatility exceeding 500 days. The device was implemented on a flexible polyethylene terephthalate substrate, validating the concept for integration into wearable electronics and smart nanodevices.

  7. Flexible non-volatile optical memory thin-film transistor device with over 256 distinct levels based on an organic bicomponent blend

    Science.gov (United States)

    Leydecker, Tim; Herder, Martin; Pavlica, Egon; Bratina, Gvido; Hecht, Stefan; Orgiu, Emanuele; Samorì, Paolo

    2016-09-01

    Organic nanomaterials are attracting a great deal of interest for use in flexible electronic applications such as logic circuits, displays and solar cells. These technologies have already demonstrated good performances, but flexible organic memories are yet to deliver on all their promise in terms of volatility, operational voltage, write/erase speed, as well as the number of distinct attainable levels. Here, we report a multilevel non-volatile flexible optical memory thin-film transistor based on a blend of a reference polymer semiconductor, namely poly(3-hexylthiophene), and a photochromic diarylethene, switched with ultraviolet and green light irradiation. A three-terminal device featuring over 256 (8 bit storage) distinct current levels was fabricated, the memory states of which could be switched with 3 ns laser pulses. We also report robustness over 70 write-erase cycles and non-volatility exceeding 500 days. The device was implemented on a flexible polyethylene terephthalate substrate, validating the concept for integration into wearable electronics and smart nanodevices.

  8. Flexible NAND-Like Organic Ferroelectric Memory Array

    NARCIS (Netherlands)

    Kam, B.; Ke, T.H.; Chasin, A.; Tyagi, M.; Cristoferi, C.; Tempelaars, K.; Breemen, A.J.J.M. van; Myny, K.; Schols, S.; Genoe, J.; Gelinck, G.H.; Heremans, P.

    2014-01-01

    We present a memory array of organic ferroelectric field-effect transistors (OFeFETs) on flexible substrates. The OFeFETs are connected serially, similar to the NAND architecture of flash memory, which offers the highest memory density of transistor memories. We demonstrate a reliable addressing

  9. Testability and Fault Tolerance for Emerging Nanoelectronic Memories

    NARCIS (Netherlands)

    Haron, N.Z.B.

    2012-01-01

    Emerging nanoelectronic memories such as Resistive Random Access Memories (RRAMs) are possible candidates to replace the conventional memory technologies such as SRAMs, DRAMs and flash memories in future computer systems. Despite their advantages such as enormous storage capacity, low-power per unit

  10. Doped SbTe phase change material in memory cells

    NARCIS (Netherlands)

    in ‘t Zandt, M.A.A.; Jedema, F.J.; Gravesteijn, Dirk J; Gravesteijn, D.J.; Attenborough, K.; Wolters, Robertus A.M.

    2009-01-01

    Phase Change Random Access Memory (PCRAM) is investigated as replacement for Flash. The memory concept is based on switching a chalcogenide from the crystalline (low ohmic) to the amorphous (high ohmic) state and vice versa. Basically two memory cell concepts exist: the Ovonic Unified Memory (OUM)

  11. Spurious dispersion effects at FLASH

    International Nuclear Information System (INIS)

    Prat, Eduard

    2009-07-01

    The performance of the Free-Electron Laser (FEL) process imposes stringent demands on the transverse trajectory and size of the electron beam. Since transverse dispersion changes off-energy particle trajectories and increases the effective beam size, dispersion must be controlled. This thesis treats the concept of dispersion in linacs, and analyses the impact of dispersion on the electron beam and on the FEL process. It presents generation mechanisms for spurious dispersion, quantifying its importance for FLASH (Free-electron Laser in Hamburg) and the XFEL (European X-ray Free-Electron Laser). A method for measuring and correcting dispersion and its implementation in FLASH is described. Experiments of dispersion e ects on the transverse beam quality and on the FEL performance are presented. (orig.)

  12. Flash x-ray cinematography

    International Nuclear Information System (INIS)

    Stein, W.E.

    1976-01-01

    Experiments intended to provide an overview of the potential capabilities and limitations of flash x-ray cinematography as a diagnostic technique for a Fast Reactor Safety Test Facility are described. The results provide estimates of the x-ray pulse intensity required to obtain adequate radiographs of an array of fuel pins in a typical reactor configuration. An estimate of the upper limit on the pulse duration imposed by the reactor background radiation was also determined. X-ray cinematography has been demonstrated at a repetition rate limited only by the recording equipment on hand at the time of these measurements. These preliminary results indicate that flash x-ray cinematography of the motion of fuel in a Fast Reactor Test Facility is technically feasible

  13. Spurious dispersion effects at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Prat, Eduard

    2009-07-15

    The performance of the Free-Electron Laser (FEL) process imposes stringent demands on the transverse trajectory and size of the electron beam. Since transverse dispersion changes off-energy particle trajectories and increases the effective beam size, dispersion must be controlled. This thesis treats the concept of dispersion in linacs, and analyses the impact of dispersion on the electron beam and on the FEL process. It presents generation mechanisms for spurious dispersion, quantifying its importance for FLASH (Free-electron Laser in Hamburg) and the XFEL (European X-ray Free-Electron Laser). A method for measuring and correcting dispersion and its implementation in FLASH is described. Experiments of dispersion e ects on the transverse beam quality and on the FEL performance are presented. (orig.)

  14. An overview of Experimental Condensed Matter Physics in Argentina by 2014, and Oxides for Non Volatile Memory Devices: The MeMOSat Project

    Science.gov (United States)

    Levy, Pablo

    2015-03-01

    In the first part of my talk, I will describe the status of the experimental research in Condensed Matter Physics in Argentina, biased towards developments related to micro and nanotechnology. In the second part, I will describe the MeMOSat Project, a consortium aimed at producing non-volatile memory devices to work in aggressive environments, like those found in the aerospace and nuclear industries. Our devices rely on the Resistive Switching mechanism, which produces a permanent but reversible change in the electrical resistance across a metal-insulator-metal structure by means of a pulsed protocol of electrical stimuli. Our project is devoted to the study of Memory Mechanisms in Oxides (MeMO) in order to establish a technological platform that tests the Resistive RAM (ReRAM) technology for aerospace applications. A review of MeMOSat's activities is presented, covering the initial Proof of Concept in ceramic millimeter sized samples; the study of different oxide-metal couples including (LaPr)2/3Ca1/3MnO, La2/3Ca1/3MnO3, YBa2Cu3O7, TiO2, HfO2, MgO and CuO; and recent miniaturized arrays of micrometer sized devices controlled by in-house designed electronics, which were launched with the BugSat01 satellite in June2014 by the argentinian company Satellogic.

  15. Fabrication of ultrahigh density metal-cell-metal crossbar memory devices with only two cycles of lithography and dry-etch procedures

    KAUST Repository

    Zong, Baoyu

    2013-05-20

    A novel approach to the fabrication of metal-cell-metal trilayer memory devices was demonstrated by using only two cycles of lithography and dry-etch procedures. The fabricated ultrahigh density crossbar devices can be scaled down to ≤70 nm in half-pitch without alignment issues. Depending on the different dry-etch mechanisms in transferring high and low density nanopatterns, suitable dry-etch angles and methods are studied for the transfer of high density nanopatterns. Some novel process methods have also been developed to eliminate the sidewall and other conversion obstacles for obtaining high density of uniform metallic nanopatterns. With these methods, ultrahigh density trilayer crossbar devices (∼2 × 1010 bit cm-2-kilobit electronic memory), which are composed of built-in practical magnetoresistive nanocells, have been achieved. This scalable process that we have developed provides the relevant industries with a cheap means to commercially fabricate three-dimensional high density metal-cell-metal nanodevices. © 2013 IOP Publishing Ltd.

  16. Electrical bistabilities and memory mechanisms of nonvolatile organic bistable devices based on exfoliated muscovite-type mica nanoparticle/poly(methylmethacrylate) nanocomposites

    Science.gov (United States)

    Lim, Won Gyu; Lee, Dea Uk; Na, Han Gil; Kim, Hyoun Woo; Kim, Tae Whan

    2018-02-01

    Organic bistable devices (OBDs) with exfoliated mica nanoparticles (NPs) embedded into an insulating poly(methylmethacrylate) (PMMA) layer were fabricated by using a spin-coating method. Current-voltage (I-V) curves for the Al/PMMA/exfoliated mica NP/PMMA/indium-tin-oxide/glass devices at 300 K showed a clockwise current hysteresis behavior due to the existence of the exfoliated muscovite-type mica NPs, which is an essential feature for bistable devices. Write-read-erase-read data showed that the OBDs had rewritable nonvolatile memories and an endurance number of ON/OFF switching for the OBDs of 102 cycles. An ON/OFF ratio of 1 × 103 was maintained for retention times larger than 1 × 104 s. The memory mechanisms of the fabricated OBDs were described by using the trapping and the tunneling processes within a PMMA active layer containing exfoliated muscovite-type mica NPs on the basis of the energy band diagram and the I-V curves.

  17. Accessing memory

    Science.gov (United States)

    Yoon, Doe Hyun; Muralimanohar, Naveen; Chang, Jichuan; Ranganthan, Parthasarathy

    2017-09-26

    A disclosed example method involves performing simultaneous data accesses on at least first and second independently selectable logical sub-ranks to access first data via a wide internal data bus in a memory device. The memory device includes a translation buffer chip, memory chips in independently selectable logical sub-ranks, a narrow external data bus to connect the translation buffer chip to a memory controller, and the wide internal data bus between the translation buffer chip and the memory chips. A data access is performed on only the first independently selectable logical sub-rank to access second data via the wide internal data bus. The example method also involves locating a first portion of the first data, a second portion of the first data, and the second data on the narrow external data bus during separate data transfers.

  18. Homogeneous-oxide stack in IGZO thin-film transistors for multi-level-cell NAND memory application

    Science.gov (United States)

    Ji, Hao; Wei, Yehui; Zhang, Xinlei; Jiang, Ran

    2017-11-01

    A nonvolatile charge-trap-flash memory that is based on amorphous indium-gallium-zinc-oxide thin film transistors was fabricated with a homogeneous-oxide structure for a multi-level-cell application. All oxide layers, i.e., tunneling layer, charge trapping layer, and blocking layer, were fabricated with Al2O3 films. The fabrication condition (including temperature and deposition method) of the charge trapping layer was different from those of the other oxide layers. This device demonstrated a considerable large memory window of 4 V between the states fully erased and programmed with the operation voltage less than 14 V. This kind of device shows a good prospect for multi-level-cell memory applications.

  19. Hot flashes and sleep in women.

    Science.gov (United States)

    Moe, Karen E

    2004-12-01

    Sleep disturbances during menopause are often attributed to nocturnal hot flashes and 'sweats' associated with changing hormone patterns. This paper is a comprehensive critical review of the research on the relationship between sleep disturbance and hot flashes in women. Numerous studies have found a relationship between self-reported hot flashes and sleep complaints. However, hot flash studies using objective sleep assessment techniques such as polysomnography, actigraphy, or quantitative analysis of the sleep EEG are surprisingly scarce and have yielded somewhat mixed results. Much of this limited evidence suggests that hot flashes are associated with objectively identified sleep disruption in at least some women. At least some of the negative data may be due to methodological issues such as reliance upon problematic self-reports of nocturnal hot flashes and a lack of concurrent measures of hot flashes and sleep. The recent development of a reliable and non-intrusive method for objectively identifying hot flashes during the night should help address the need for substantial additional research in this area. Several areas of clinical relevance are described, including the effects of discontinuing combined hormone therapy (estrogen plus progesterone) or estrogen-only therapy, the possibility of hot flashes continuing for many years after menopause, and the link between hot flashes and depression.

  20. Cognitive memory.

    Science.gov (United States)

    Widrow, Bernard; Aragon, Juan Carlos

    2013-05-01

    . Neural networks are an important component of the human memory system, and their purpose is for information retrieval, not for information storage. The brain's neural networks are analog devices, subject to drift and unplanned change. Only with constant training is reliable action possible. Good training time is during sleep and while awake and making use of one's memory. A cognitive memory is a learning system. Learning involves storage of patterns or data in a cognitive memory. The learning process for cognitive memory is unsupervised, i.e. autonomous. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Dual-functional Memory and Threshold Resistive Switching Based on the Push-Pull Mechanism of Oxygen Ions

    KAUST Repository

    Huang, Yi-Jen

    2016-04-07

    The combination of nonvolatile memory switching and volatile threshold switching functions of transition metal oxides in crossbar memory arrays is of great potential for replacing charge-based flash memory in very-large-scale integration. Here, we show that the resistive switching material structure, (amorphous TiOx)/(Ag nanoparticles)/(polycrystalline TiOx), fabricated on the textured-FTO substrate with ITO as the top electrode exhibits both the memory switching and threshold switching functions. When the device is used for resistive switching, it is forming-free for resistive memory applications with low operation voltage (<±1 V) and self-compliance to current up to 50 μA. When it is used for threshold switching, the low threshold current is beneficial for improving the device selectivity. The variation of oxygen distribution measured by energy dispersive X-ray spectroscopy and scanning transmission electron microscopy indicates the formation or rupture of conducting filaments in the device at different resistance states. It is therefore suggested that the push and pull actions of oxygen ions in the amorphous TiOx and polycrystalline TiOx films during the voltage sweep account for the memory switching and threshold switching properties in the device.

  2. Machine protection for FLASH and the European XFEL

    International Nuclear Information System (INIS)

    Froehlich, Lars

    2009-05-01

    The Free-Electron Laser in Hamburg (FLASH) and the future European X-Ray Free-Electron Laser (XFEL) are sources of brilliant extremeultraviolet and X-ray radiation pulses. Both facilities are based on superconducting linear accelerators (linacs) that can produce and transport electron beams of high average power. With up to 90 kW or up to 600 kW of power, respectively, these beams hold a serious potential to damage accelerator components. This thesis discusses several passive and active machine protection measures needed to ensure safe operation. At FLASH, dark current from the rf gun electron source has activated several accelerator components to unacceptable radiation levels. Its transport through the linac is investigated with detailed tracking simulations using a parallelized and enhanced version of the tracking code Astra; possible remedies are evaluated. Beam losses can lead to the demagnetization of permanent magnet insertion devices. A number of beam loss scenarios typical for FLASH are investigated with shower simulations. A shielding setup is designed and its efficiency is evaluated. For the design parameters of FLASH, it is concluded that the average relative beam loss in the undulators must be controlled to a level of about 10 -8 . FLASH is equipped with an active machine protection system (MPS) comprising more than 80 photomultiplier-based beam loss monitors and several subsystems. The maximum response time to beam losses is less than 4 μs. Setup procedures and calibration algorithms for MPS subsystems and components are introduced and operational problems are addressed. Finally, an architecture for a fully programmable machine protection system for the XFEL is presented. Several options for the topology of this system are reviewed, with the result that an availability goal of at least 0.999 for the MPS is achievable with moderate hardware requirements. (orig.)

  3. Machine protection for FLASH and the European XFEL

    Energy Technology Data Exchange (ETDEWEB)

    Froehlich, Lars

    2009-05-15

    The Free-Electron Laser in Hamburg (FLASH) and the future European X-Ray Free-Electron Laser (XFEL) are sources of brilliant extremeultraviolet and X-ray radiation pulses. Both facilities are based on superconducting linear accelerators (linacs) that can produce and transport electron beams of high average power. With up to 90 kW or up to 600 kW of power, respectively, these beams hold a serious potential to damage accelerator components. This thesis discusses several passive and active machine protection measures needed to ensure safe operation. At FLASH, dark current from the rf gun electron source has activated several accelerator components to unacceptable radiation levels. Its transport through the linac is investigated with detailed tracking simulations using a parallelized and enhanced version of the tracking code Astra; possible remedies are evaluated. Beam losses can lead to the demagnetization of permanent magnet insertion devices. A number of beam loss scenarios typical for FLASH are investigated with shower simulations. A shielding setup is designed and its efficiency is evaluated. For the design parameters of FLASH, it is concluded that the average relative beam loss in the undulators must be controlled to a level of about 10{sup -8}. FLASH is equipped with an active machine protection system (MPS) comprising more than 80 photomultiplier-based beam loss monitors and several subsystems. The maximum response time to beam losses is less than 4 {mu}s. Setup procedures and calibration algorithms for MPS subsystems and components are introduced and operational problems are addressed. Finally, an architecture for a fully programmable machine protection system for the XFEL is presented. Several options for the topology of this system are reviewed, with the result that an availability goal of at least 0.999 for the MPS is achievable with moderate hardware requirements. (orig.)

  4. Emerging memories

    Science.gov (United States)

    Baldi, Livio; Bez, Roberto; Sandhu, Gurtej

    2014-12-01

    Memory is a key component of any data processing system. Following the classical Turing machine approach, memories hold both the data to be processed and the rules for processing them. In the history of microelectronics, the distinction has been rather between working memory, which is exemplified by DRAM, and storage memory, exemplified by NAND. These two types of memory devices now represent 90% of all memory market and 25% of the total semiconductor market, and have been the technology drivers in the last decades. Even if radically different in characteristics, they are however based on the same storage mechanism: charge storage, and this mechanism seems to be near to reaching its physical limits. The search for new alternative memory approaches, based on more scalable mechanisms, has therefore gained new momentum. The status of incumbent memory technologies and their scaling limitations will be discussed. Emerging memory technologies will be analyzed, starting from the ones that are already present for niche applications, and which are getting new attention, thanks to recent technology breakthroughs. Maturity level, physical limitations and potential for scaling will be compared to existing memories. At the end the possible future composition of memory systems will be discussed.

  5. Multiple negative differential resistance devices with ultra-high peak-to-valley current ratio for practical multi-valued logic and memory applications

    Science.gov (United States)

    Shin, Sunhae; Rok Kim, Kyung

    2015-06-01

    In this paper, we propose a novel multiple negative differential resistance (NDR) device with ultra-high peak-to-valley current ratio (PVCR) over 106 by combining tunnel diode with a conventional MOSFET, which suppresses the valley current with transistor off-leakage level. Band-to-band tunneling (BTBT) in tunnel junction provides the first peak, and the second peak and valley are generated from the suppression of diffusion current in tunnel diode by the off-state MOSFET. The multiple NDR curves can be controlled by doping concentration of tunnel junction and the threshold voltage of MOSFET. By using complementary multiple NDR devices, five-state memory is demonstrated only with six transistors.

  6. Implementation of nitrogen-doped titanium-tungsten tunable heater in phase change random access memory and its effects on device performance

    International Nuclear Information System (INIS)

    Tan, Chun Chia; Zhao, Rong; Chong, Tow Chong; Shi, Luping

    2014-01-01

    Nitrogen-doped titanium-tungsten (N-TiW) was proposed as a tunable heater in Phase Change Random Access Memory (PCRAM). By tuning N-TiW's material properties through doping, the heater can be tailored to optimize the access speed and programming current of PCRAM. Experiments reveal that N-TiW's resistivity increases and thermal conductivity decreases with increasing nitrogen-doping ratio, and N-TiW devices displayed (∼33% to ∼55%) reduced programming currents. However, there is a tradeoff between the current and speed for heater-based PCRAM. Analysis of devices with different N-TiW heaters shows that N-TiW doping levels could be optimized to enable low RESET currents and fast access speeds.

  7. Construction and performance of large flash chambers

    International Nuclear Information System (INIS)

    Taylor, F.E.; Bogert, D.; Fisk, R.; Stutte, L.; Walker, J.K.; Wolfson, J.; Abolins, M.; Ernwein, J.; Owen, D.; Lyons, T.

    1979-01-01

    The construction and performance of 12' x 12' flash chambers used in a 340 ton neutrino detector under construction at Fermilab is described. The flash chambers supply digital information with a spatial resolution of 0.2'', and are used to finely sample the shower development of the reaction products of neutrino interactions. The flash chambers are easy and inexpensive to build and are electronically read out

  8. Transmission electron microscopy assessment of conductive-filament formation in Ni-HfO2-Si resistive-switching operational devices

    Science.gov (United States)

    Martín, Gemma; González, Mireia B.; Campabadal, Francesca; Peiró, Francesca; Cornet, Albert; Estradé, Sònia

    2018-01-01

    Resistive random-access memory (ReRAM) devices are currently the object of extensive research to replace flash non-volatile memory. However, elucidation of the conductive-filament formation mechanisms in ReRAM devices at nanoscale is mandatory. In this study, the different states created under real operation conditions of HfO2-based ReRAM devices are characterized through transmission electron microscopy and electron energy-loss spectroscopy. The physical mechanism behind the conductive-filament formation in Ni/HfO2/Si ReRAM devices based on the diffusion of Ni from the electrode to the Si substrate and of Si from the substrate to the electrode through the HfO2 layer is demonstrated.

  9. Huge music archives on mobile devices

    DEFF Research Database (Denmark)

    Blume, H.; Bischl, B.; Botteck, M.

    2011-01-01

    The availability of huge nonvolatile storage capacities such as flash memory allows large music archives to be maintained even in mobile devices. With the increase in size, manual organization of these archives and manual search for specific music becomes very inconvenient. Automated dynamic...... organization enables an attractive new class of applications for managing ever-increasing music databases. For these types of applications, extraction of music features as well as subsequent feature processing and music classification have to be performed. However, these are computationally intensive tasks...... and difficult to tackle on mobile platforms. Against this background, we provided an overview of algorithms for music classification as well as their computation times and other hardware-related aspects, such as power consumption on various hardware architectures. For mobile platforms such as smartphones...

  10. Flash CS5 The Missing Manual

    CERN Document Server

    Grover, Chris

    2010-01-01

    Once you know how to use Flash, you can create everything from simple animations to high-end desktop applications, but it's a complex tool that can be difficult to master on your own-unless you have this Missing Manual. This book will help you learn all you need to know about Flash CS5 to create animations that bring your ideas to life. Learn animation basics. Find everything you need to know to get started with FlashMaster the Flash tools. Learn the animation and effects toolset, with clear explanations and hands-on examplesUse 3D effects. Rotate and put objects in motion in three dimensions

  11. Search Engine Optimization for Flash Best Practices for Using Flash on the Web

    CERN Document Server

    Perkins, Todd

    2009-01-01

    Search Engine Optimization for Flash dispels the myth that Flash-based websites won't show up in a web search by demonstrating exactly what you can do to make your site fully searchable -- no matter how much Flash it contains. You'll learn best practices for using HTML, CSS and JavaScript, as well as SWFObject, for building sites with Flash that will stand tall in search rankings.

  12. Formation of a Mental Abacus for Computation and Its Use as a Memory Device for Digits: A Developmental Study.

    Science.gov (United States)

    Hatano, Giyoo; And Others

    1987-01-01

    Examined whether representational changes in digit memory are functions of children's expertise in mental abacus operation when abacus operators reproduced series of digits forward or backward. Found skilled operators equally facile with forward and backward reproduction, but novices slower going backward. Suggests advanced operators apply their…

  13. Measurement of hot flashes by sternal skin conductance and subjective hot flash report in Puebla, Mexico.

    Science.gov (United States)

    Sievert, Lynnette Leidy; Freedman, Robert R; Garcia, Jesus Zarain; Foster, Jennifer W; del Carmen Romano Soriano, Ma; Longcope, Christopher; Franz, Charlene

    2002-01-01

    To measure hot flashes by sternal skin conductance in an urban Mexican population and to determine variables associated with hot flash reporting and measurement. From June 1999 to August 2000, 67 perimenopausal women aged 40 to 65 years participated in interviews, anthropometric measures, and a 2-h recording of sternal skin conductance. Changes in sweating were used to demonstrate the presence/absence of a hot flash. During the test, women were asked to report if they experienced a hot flash. During the study period, 10 women reported and demonstrated every hot flash, 24 women never reported or demonstrated a hot flash, 7 demonstrated hot flashes but did not report any of them, 7 reported hot flashes but did not demonstrate any of them, and 19 showed a mixture of responses. Women who demonstrated hot flashes by sternal skin conductance were measured in a warmer room, had more years of education, consumed more eggs as a child, recalled a heavier weight at age 18, and had a lower body mass index at interview compared with women who did not demonstrate hot flashes by sternal skin conductance. Women who subjectively reported hot flashes were measured in a warmer room, were more likely to be postmenopausal, reported more frequent consumption of coffee, and spent fewer months breast-feeding their last child compared with women who did not report the experience of hot flashes during the testing period. Room temperature explained part of the variation between women who did and did not demonstrate hot flashes via sternal skin conductance, between women who did and did not report the experience of hot flashes, and between women who did and did not demonstrate concordance in objective and subjective measures. In addition to room temperature, coffee intake, months spent breast-feeding the last child, and recalled weight at age 18 were important variables predicting hot flash experience.

  14. Rh-flash acquisition card

    International Nuclear Information System (INIS)

    Bourrion, O.

    2003-01-01

    The rh-flash card main purpose is to convert and store the image of the analog data present at input into an output buffer, namely in a given timing window besides a stop signal (like a digital oscilloscope). It is conceived in VME format 1U wide with an additional connector. Novelty of this card is its ability to sample at a high frequency, due to flash coders, and this at a high repetition rate. To do that the card allows the storage of the data considered 'useful' and that is done by storing only the data exceeding a certain threshold. This can be useful for instance for viewing peaks in a spectrum, and obtaining their relative location. The goal is to stock and process the data sampled before and after the arrival of a stop signal (what entails a storage depth). A threshold is defined and any peak exceeding its level will really be stored in the output buffer which is readable through the VME bus. The peak values will be stored as well as m preceding and n subsequent values (both programmable). Obviously, if the threshold is zero the system of data processing is off and all data will be stored. The document is structured on six sections titled: 1. Description; 2. Specifications; 3. Explaining the design of channels; 4. Explaining the shared part of the design; 5. Addressing (→ user guide); 6. Software precautions. (author)

  15. On multiphase negative flash for ideal solutions

    DEFF Research Database (Denmark)

    Yan, Wei; Stenby, Erling Halfdan

    2012-01-01

    There is a recent interest to solve multiphase negative flash problems where the phase amounts can be negative for normal positive feed composition. Solving such a negative flash problem using successive substitution needs an inner loop for phase distribution calculation at constant fugacity...

  16. Set statistics in conductive bridge random access memory device with Cu/HfO2/Pt structure

    International Nuclear Information System (INIS)

    Zhang, Meiyun; Long, Shibing; Wang, Guoming; Xu, Xiaoxin; Li, Yang; Liu, Qi; Lv, Hangbing; Liu, Ming; Lian, Xiaojuan; Miranda, Enrique; Suñé, Jordi

    2014-01-01

    The switching parameter variation of resistive switching memory is one of the most important challenges in its application. In this letter, we have studied the set statistics of conductive bridge random access memory with a Cu/HfO 2 /Pt structure. The experimental distributions of the set parameters in several off resistance ranges are shown to nicely fit a Weibull model. The Weibull slopes of the set voltage and current increase and decrease logarithmically with off resistance, respectively. This experimental behavior is perfectly captured by a Monte Carlo simulator based on the cell-based set voltage statistics model and the Quantum Point Contact electron transport model. Our work provides indications for the improvement of the switching uniformity

  17. FLASH Interface; a GUI for managing runtime parameters in FLASH simulations

    Science.gov (United States)

    Walker, Christopher; Tzeferacos, Petros; Weide, Klaus; Lamb, Donald; Flocke, Norbert; Feister, Scott

    2017-10-01

    We present FLASH Interface, a novel graphical user interface (GUI) for managing runtime parameters in simulations performed with the FLASH code. FLASH Interface supports full text search of available parameters; provides descriptions of each parameter's role and function; allows for the filtering of parameters based on categories; performs input validation; and maintains all comments and non-parameter information already present in existing parameter files. The GUI can be used to edit existing parameter files or generate new ones. FLASH Interface is open source and was implemented with the Electron framework, making it available on Mac OSX, Windows, and Linux operating systems. The new interface lowers the entry barrier for new FLASH users and provides an easy-to-use tool for experienced FLASH simulators. U.S. Department of Energy (DOE), NNSA ASC/Alliances Center for Astrophysical Thermonuclear Flashes, U.S. DOE NNSA ASC through the Argonne Institute for Computing in Science, U.S. National Science Foundation.

  18. Endurance Write Speed Tradeoffs in Nonvolatile Memories

    OpenAIRE

    Strukov, Dmitri

    2015-01-01

    We derive phenomenological model for endurance-write time switching tradeoff for nonvolatile memories with thermally activated switching mechanisms. The model predicts linear to cubic dependence of endurance on write time for metal oxide memristors and flash memories, which is partially supported by experimental data for the breakdown of metal-oxide thin films.

  19. High performance organic nonvolatile memory transistors based on HfO2 and poly(α-methylstyrene) electret hybrid charge-trapping layers

    Science.gov (United States)

    Xu, W. C.; He, H. X.; Jing, X. S.; Wu, S. J.; Zhang, Z.; Gao, J. W.; Gao, X. S.; Zhou, G. F.; Lu, X. B.; Liu, J.-M.

    2017-08-01

    In this work, we fabricated a high performance flash-type organic nonvolatile memory transistor, which adopted polymer-electret poly(α-methylstyrene) (PαMS) and HfO2 films as hybrid charge trapping layer (CTL). Compared with a single HfO2 or PαMS CTL structure, the hybrid HfO2/PαMS CTL structure can provide enhanced charge trapping efficiency to increase the device operation speed and reduce the leakage current to boost the device reliability. The fabricated nonvolatile organic memory transistors with the hybrid CTL shows excellent electrical properties, including low operation voltage (8 V), high speed (erase cycles). The present work provides useful idea for the design of future low-power consumption and highly reliable organic nonvolatile memories.

  20. Detection and spectral measurements of coherent synchrotron radiation at FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Behrens, Christopher

    2010-02-15

    The operation of high-gain free-electron laser (FEL) underlies tremendous demands on high quality electron beams with high peak currents. At the Free-Electron-Laser in Hamburg (FLASH), two magnetic bunch compressors are used to compress the electron bunches longitudinally. In the bunch compressor magnets, these short electron bunches generate coherent synchrotron radiation (CSR). This CSR contains information on the longitudinal bunch profile, which is relevant for driving an FEL. In order to investigate coherent synchrotron radiation at the second bunch compressor BC3 at FLASH, a new setup behind the last dipole was installed. For the detection of coherent synchrotron radiation, which is emitted in the infrared regime, pyroelectric detectors were used. These pyroelectric detectors have been calibrated at the free-electron laser FELIX in the wavelength range from 5 {mu}m to 110 {mu}m. For characterisation of the emitted radiation, a transverse scanning device was used to measure the transverse intensity distribution. Various transmission filters were used to obtain additional information about the spectral content. In order to get spectral information with high resolution over a wide wavelength range, a rotating mirror spectrometer using reflective blazed gratings was installed. Using this spectrometer, the first spectral measurements of coherent synchrotron radiation at FLASH in a wavelength range from 10 {mu}m to 160 {mu}m were done. (orig.)