WorldWideScience

Sample records for bipolar transistor structures

  1. Review of Heterojunctin Bipolar Transistor Structure, Applications, and Reliability

    Science.gov (United States)

    Lee, C.; Kayali, S.

    1993-01-01

    Heterojunction Bipolar Transistors (HBTs) are increasingly employed in high frequency, high linerity, and high efficiency applications. As the utilization of these devices becomes more widespread, their operation will be viewed with more scrutiny.

  2. Magnetic bipolar transistor

    OpenAIRE

    Fabian, Jaroslav; Zutic, Igor; Sarma, S. Das

    2003-01-01

    A magnetic bipolar transistor is a bipolar junction transistor with one or more magnetic regions, and/or with an externally injected nonequilibrium (source) spin. It is shown that electrical spin injection through the transistor is possible in the forward active regime. It is predicted that the current amplification of the transistor can be tuned by spin.

  3. STRUCTURAL AND TECHNOLOGICAL PARAMETERS AFFECTING THE BIPOLAR STATIC INDUCTION TRANSISTOR (BSIT RESISTANCE

    Directory of Open Access Journals (Sweden)

    T. A. Ismailov

    2016-01-01

    Full Text Available Aim. The aim of the study is to determine the impact of structural and technological parameters on the resistance of the bipolar static induction transistor.Methods. The paper provides a comparative analysis of the advantages of bipolar static induction transistor compared to the bipolar power transistors, MOSFETs and insulated-gate bipolar transistor (IGBT. Considered are structural and technological parameters that influence the resistance of BSIT-transistor.Result. As a result of experimental study on silicon substrates were formed test prototypes of BSIT transistor structure, are presented calculation and experimental works. Obtained are the resistance dependencies of the transistor cell on the thickness of the epitaxial film; the resistance dependencies of BSIT transistor cell on the effective gate length for different values of the impurity concentration in the epitaxial film; dependencies resistance of the transistor cell on the gate length at different values of the epitaxial film thickness; the resistance dependencies of BSIT transistor cell on the distance between the mask for the p-region and the gate; dependencies on the multiplication the cell resistance by its area on the gate length.Conclusion. When increasing the gate length (Lk and the mask length for the p-region (lp + in the transistor structure, the resistance decreases and the dependence of multiplication of the cell resistance by its area Q on the gate length has this case the minimum.

  4. CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES: Thermal analytic model of current gain for bipolar junction transistor-bipolar static induction transistor compound device

    Science.gov (United States)

    Zhang, You-Run; Zhang, Bo; Li, Ze-Hong; Lai, Chang-Jin; Li, Zhao-Ji

    2009-02-01

    This paper proposes a thermal analytical model of current gain for bipolar junction transistor-bipolar static induction transistor (BJT-BSIT) compound device in the low current operation. It also proposes a best thermal compensating factor to the compound device that indicates the relationship between the thermal variation rate of current gain and device structure. This is important for the design of compound device to be optimized. Finally, the analytical model is found to be in good agreement with numerical simulation and experimental results. The test results demonstrate that thermal variation rate of current gain is below 10% in 25 °C-85°C and 20% in -55°C-25°C.

  5. Ion bipolar junction transistors.

    Science.gov (United States)

    Tybrandt, Klas; Larsson, Karin C; Richter-Dahlfors, Agneta; Berggren, Magnus

    2010-06-01

    Dynamic control of chemical microenvironments is essential for continued development in numerous fields of life sciences. Such control could be achieved with active chemical circuits for delivery of ions and biomolecules. As the basis for such circuitry, we report a solid-state ion bipolar junction transistor (IBJT) based on conducting polymers and thin films of anion- and cation-selective membranes. The IBJT is the ionic analogue to the conventional semiconductor BJT and is manufactured using standard microfabrication techniques. Transistor characteristics along with a model describing the principle of operation, in which an anionic base current amplifies a cationic collector current, are presented. By employing the IBJT as a bioelectronic circuit element for delivery of the neurotransmitter acetylcholine, its efficacy in modulating neuronal cell signaling is demonstrated.

  6. Bipolar transistor in VESTIC technology: prototype

    Science.gov (United States)

    Mierzwiński, Piotr; Kuźmicz, Wiesław; Domański, Krzysztof; Tomaszewski, Daniel; Głuszko, Grzegorz

    2016-12-01

    VESTIC technology is an alternative for traditional CMOS technology. This paper presents first measurement data of prototypes of VES-BJT: bipolar transistors in VESTIC technology. The VES-BJT is a bipolar transistor on the SOI substrate with symmetric lateral structure and both emitter and collector made of polysilicon. The results indicate that VES-BJT can be a device with useful characteristics. Therefore, VESTIC technology has the potential to become a new BiCMOS-type technology with some unique properties.

  7. Producing of pover GaAs structures of bipolar and field-effect transistor by CVD-method

    Directory of Open Access Journals (Sweden)

    Voronin V. A.

    2010-03-01

    Full Text Available Investigation results in technology of doping Sn and Bi of perfect GaAs structures preparation by the lowe-temperature isothermal chloride epitaxy method are presented. A complex problem has been solved to obtain planar layers of the n+–n–n0–p type bipolar transistors and planar layers of the i–n0–n–n+ type Schottky field-effect transistors. Heterogenetty in the thickness less than 3% and doping level less than 5% has been achieved. This allowed to get the discrete Schottky field-effect transistors with improved operation characteristics.

  8. Heat removal from bipolar transistor by loop heat pipe with nickel and copper porous structures.

    Science.gov (United States)

    Nemec, Patrik; Smitka, Martin; Malcho, Milan

    2014-01-01

    Loop heat pipes (LHPs) are used in many branches of industry, mainly for cooling of electrical elements and systems. The loop heat pipe is a vapour-liquid phase-change device that transfers heat from evaporator to condenser. One of the most important parts of the LHP is the porous wick structure. The wick structure provides capillary force to circulate the working fluid. To achieve good thermal performance of LHP, capillary wicks with high permeability and porosity and fine pore radius are expected. The aim of this work was to develop porous structures from copper and nickel powder with different grain sizes. For experiment copper powder with grain size of 50 and 100 μm and nickel powder with grain size of 10 and 25 μm were used. Analysis of these porous structures and LHP design are described in the paper. And the measurements' influences of porous structures in LHP on heat removal from the insulated gate bipolar transistor (IGBT) have been made.

  9. Heat Removal from Bipolar Transistor by Loop Heat Pipe with Nickel and Copper Porous Structures

    Directory of Open Access Journals (Sweden)

    Patrik Nemec

    2014-01-01

    Full Text Available Loop heat pipes (LHPs are used in many branches of industry, mainly for cooling of electrical elements and systems. The loop heat pipe is a vapour-liquid phase-change device that transfers heat from evaporator to condenser. One of the most important parts of the LHP is the porous wick structure. The wick structure provides capillary force to circulate the working fluid. To achieve good thermal performance of LHP, capillary wicks with high permeability and porosity and fine pore radius are expected. The aim of this work was to develop porous structures from copper and nickel powder with different grain sizes. For experiment copper powder with grain size of 50 and 100 μm and nickel powder with grain size of 10 and 25 μm were used. Analysis of these porous structures and LHP design are described in the paper. And the measurements’ influences of porous structures in LHP on heat removal from the insulated gate bipolar transistor (IGBT have been made.

  10. Total Dose Effects in Conventional Bipolar Transistors

    Science.gov (United States)

    Johnston, A. H.; Swift, G. W.; Rax, B. G.

    1994-01-01

    This paper examines various factors in bipolar device construction and design, and discusses their impact on radiation hardness. The intent of the paper is to improve understanding of the underlying mechanisms for practical devices without special test structures, and to provide (1) guidance in ways to select transistor designs that are more resistant to radiation damage, and (2) methods to estimate the maximum amount of damage that might be expected from a basic transistor design. The latter factor is extremely important in assessing the risk that future lots of devices will be substantially below design limits, which are usually based on test data for older devices.

  11. Copper-Based OHMIC Contracts for the Si/SiGe Heterojunction Bipolar Transistor Structure

    Science.gov (United States)

    Das, Kalyan; Hall, Harvey

    1999-01-01

    Silicon based heterojunction bipolar transistors (HBT) with SiGe base are potentially important devices for high-speed and high-frequency microelectronics. These devices are particularly attractive as they can be fabricated using standard Si processing technology. However, in order to realize the full potential of devices fabricated in this material system, it is essential to be able to form low resistance ohmic contacts using low thermal budget process steps and have full compatibility with VLSI/ULSI processing. Therefore, a study was conducted in order to better understand the contact formation and to develop optimized low resistance contacts to layers with doping densities corresponding to the p-type SiGe base and n-type Si emitter regions of the HBTS. These as-grown doped layers were implanted with BF(sub 2) up to 1 X 10(exp 16)/CM(exp 2) and As up to 5 x 10(exp 15)/CM2, both at 30 keV for the p-type SiGe base and n-type Si emitter layers, respectively, in order to produce a low sheet resistance surface layer. Standard transfer length method (TLM) contact pads on both p and n type layers were deposited using an e-beam evaporated trilayer structure of Ti/CufTi/Al (25)A/1500A/250A/1000A). The TLM pads were delineated by a photoresist lift-off procedure. These contacts in the as-deposited state were ohmic, with specific contact resistances for the highest implant doses of the order of 10(exp -7) ohm-CM2 and lower.

  12. Nanofluidic diode and bipolar transistor.

    Science.gov (United States)

    Daiguji, Hirofumi; Oka, Yukiko; Shirono, Katsuhiro

    2005-11-01

    Theoretical modeling of ionic distribution and transport in a nanochannel containing a surface charge on its wall, 30 nm high and 5 microm long, suggests that ionic current can be controlled by locally modifying the surface charge density through a gate electrode, even if the electrical double layers are not overlapped. When the surface charge densities at the right and left halves of a channel are the same absolute value but of different signs, this could form the basis of a nanofluidic diode. When the surface charge density at the middle part of a channel is modified, this could form the basis of a nanofluidic bipolar transistor.

  13. Voltage regulator for battery power source. [using a bipolar transistor

    Science.gov (United States)

    Black, J. M. (Inventor)

    1979-01-01

    A bipolar transistor in series with the battery as the control element also in series with a zener diode and a resistor is used to maintain a predetermined voltage until the battery voltage decays to very nearly the predetermined voltage. A field effect transistor between the base of the bipolar transistor and a junction between the zener diode and resistor regulates base current of the bipolar transistor, thereby regulating the conductivity of the bipolar transistor for control of the output voltage.

  14. A gallium phosphide high-temperature bipolar junction transistor

    Science.gov (United States)

    Zipperian, T. E.; Dawson, L. R.; Chaffin, R. J.

    1981-01-01

    Preliminary results are reported on the development of a high temperature (350 C) gallium phosphide bipolar junction transistor (BJT) for geothermal and other energy applications. This four-layer p(+)n(-)pp(+) structure was formed by liquid phase epitaxy using a supercooling technique to insure uniform nucleation of the thin layers. Magnesium was used as the p-type dopant to avoid excessive out-diffusion into the lightly doped base. By appropriate choice of electrodes, the device may also be driven as an n-channel junction field-effect transistor. The initial design suffers from a series resistance problem which limits the transistor's usefulness at high temperatures.

  15. Magnetoamplification in a bipolar magnetic junction transistor.

    Science.gov (United States)

    Rangaraju, N; Peters, J A; Wessels, B W

    2010-09-10

    We have demonstrated the first bipolar magnetic junction transistor using a dilute magnetic semiconductor. For an InMnAs p-n-p transistor magnetoamplification is observed at room temperature. The observed magnetoamplification is attributed to the magnetoresistance of the magnetic semiconductor InMnAs heterojunction. The magnetic field dependence of the transistor characteristics confirm that the magnetoamplification results from the junction magnetoresistance. To describe the experimentally observed transistor characteristics, we propose a modified Ebers-Moll model that includes a series magnetoresistance attributed to spin-selective conduction. The capability of magnetic field control of the amplification in an all-semiconductor transistor at room temperature potentially enables the creation of new computer logic architecture where the spin of the carriers is utilized.

  16. Radiation Damage In Advanced Bipolar Transistors

    Science.gov (United States)

    Zoutendyk, John A.; Goben, Charles A.; Berndt, Dale F.

    1989-01-01

    Report describes measurements of common-emitter current gains (hFE) of advanced bipolar silicon transistors before, during, and after irradiation with 275-MeV bromine ions, 2.5-MeV electrons, and conductivity rays from cobalt-60 atoms.

  17. Bipolar-FET combinational power transistors for power conversion applications

    Science.gov (United States)

    Chen, D. Y.; Chin, S. A.

    1984-01-01

    Four bipolar-FET (field-effect transistor) combinational transistor configurations are compared from the application point of view. The configurations included are FET-Darlington (cascade), emitter-open switch (cascode), parallel configuration, and FET-gated bipolar transistors (FGT).

  18. Theoretical values of various parameters in the Gummel-Poon model of a bipolar junction transistor

    Science.gov (United States)

    Benumof, R.; Zoutendyk, J.

    1986-01-01

    Various parameters in the Gummel-Poon model of a bipolar junction transistor are expressed in terms of the basic structure of a transistor. A consistent theoretical approach is used which facilitates an understanding of the foundations and limitations of the derived formulas. The results enable one to predict how changes in the geometry and composition of a transistor would affect performance.

  19. A novel 4H-SiC lateral bipolar junction transistor structure with high voltage and high current gain

    Science.gov (United States)

    Deng, Yong-Hui; Xie, Gang; Wang, Tao; Sheng, Kuang

    2013-09-01

    In this paper, a novel structure of a 4H-SiC lateral bipolar junction transistor (LBJT) with a base field plate and double RESURF in the drift region is presented. Collector-base junction depletion extension in the base region is restricted by the base field plate. Thin base as well as low base doping of the LBJT therefore can be achieved under the condition of avalanche breakdown. Simulation results show that thin base of 0.32 μm and base doping of 3 × 1017 cm-3 are obtained, and corresponding current gain is as high as 247 with avalanche breakdown voltage of 3309 V when the drift region length is 30 μm. Besides, an investigation of a 4H-SiC vertical BJT (VBJT) with comparable breakdown voltage (3357 V) shows that the minimum base width of 0.25 μm and base doping as high as 8 × 1017 cm-3 contribute to a maximum current gain of only 128.

  20. Polyphosphonium-based ion bipolar junction transistors.

    Science.gov (United States)

    Gabrielsson, Erik O; Tybrandt, Klas; Berggren, Magnus

    2014-11-01

    Advancements in the field of electronics during the past few decades have inspired the use of transistors in a diversity of research fields, including biology and medicine. However, signals in living organisms are not only carried by electrons but also through fluxes of ions and biomolecules. Thus, in order to implement the transistor functionality to control biological signals, devices that can modulate currents of ions and biomolecules, i.e., ionic transistors and diodes, are needed. One successful approach for modulation of ionic currents is to use oppositely charged ion-selective membranes to form so called ion bipolar junction transistors (IBJTs). Unfortunately, overall IBJT device performance has been hindered due to the typical low mobility of ions, large geometries of the ion bipolar junction materials, and the possibility of electric field enhanced (EFE) water dissociation in the junction. Here, we introduce a novel polyphosphonium-based anion-selective material into npn-type IBJTs. The new material does not show EFE water dissociation and therefore allows for a reduction of junction length down to 2 μm, which significantly improves the switching performance of the ion transistor to 2 s. The presented improvement in speed as well the simplified design will be useful for future development of advanced iontronic circuits employing IBJTs, for example, addressable drug-delivery devices.

  1. Neutrality in bipolar structures

    DEFF Research Database (Denmark)

    Montero, Javier; Rodríguez, J. Tinguaro; Franco, Camilo

    2014-01-01

    In this paper, we want to stress that bipolar knowledge representation naturally allows a family of middle states which define as a consequence different kinds of bipolar structures. These bipolar structures are deeply related to the three types of bipolarity introduced by Dubois and Prade, but our...... approach offers a systematic explanation of how such bipolar structures appear and can be identified....

  2. Simulation of Heating of an Oil-Cooled Insulated Gate Bipolar Transistors Converter Model

    National Research Council Canada - National Science Library

    Ovrebo, Gregory

    2004-01-01

    I used SolidWorks a three-dimensional modeling software, and FloWorks, a fluid dynamics analysis tool, to simulate oil flow and heat transfer in a heat sink structure attached to three insulated gate bipolar transistors...

  3. Vertical bipolar charge plasma transistor with buried metal layer.

    Science.gov (United States)

    Nadda, Kanika; Kumar, M Jagadesh

    2015-01-19

    A self-aligned vertical Bipolar Charge Plasma Transistor (V-BCPT) with a buried metal layer between undoped silicon and buried oxide of the silicon-on-insulator substrate, is reported in this paper. Using two-dimensional device simulation, the electrical performance of the proposed device is evaluated in detail. Our simulation results demonstrate that the V-BCPT not only has very high current gain but also exhibits high BVCEO · f(T) product making it highly suitable for mixed signal high speed circuits. The proposed device structure is also suitable for realizing doping-less bipolar charge plasma transistor using compound semiconductors such as GaAs, SiC with low thermal budgets. The device is also immune to non-ideal current crowding effects cropping up at high current densities.

  4. Dose Rate Effects in Linear Bipolar Transistors

    Science.gov (United States)

    Johnston, Allan; Swimm, Randall; Harris, R. D.; Thorbourn, Dennis

    2011-01-01

    Dose rate effects are examined in linear bipolar transistors at high and low dose rates. At high dose rates, approximately 50% of the damage anneals at room temperature, even though these devices exhibit enhanced damage at low dose rate. The unexpected recovery of a significant fraction of the damage after tests at high dose rate requires changes in existing test standards. Tests at low temperature with a one-second radiation pulse width show that damage continues to increase for more than 3000 seconds afterward, consistent with predictions of the CTRW model for oxides with a thickness of 700 nm.

  5. Controlled ion-beam transformation of silicon bipolar microwave power transistor's characteristics

    International Nuclear Information System (INIS)

    Solodukha, V.A.; Snitovskij, Yu.P.

    2015-01-01

    In this article, a method for changing the silicon bipolar microwave power transistor's characteristics in a direct and deliberate manner by modifying the chemical composition at the molybdenum - silicon boundary, the electro-physical properties of molybdenum - silicon contacts, and the electrophysical characteristics of transistor structure areas by the phosphorus ions irradiation of generated ohmic molybdenum - silicon contacts to the transistor emitters is proposed for the first time. The possibilities of this method are investigated and confirmed experimentally. (authors)

  6. Precursor Parameter Identification for Insulated Gate Bipolar Transistor (IGBT) Prognostics

    Data.gov (United States)

    National Aeronautics and Space Administration — Precursor parameters have been identified to enable development of a prognostic approach for insulated gate bipolar transistors (IGBT). The IGBT were subjected to...

  7. High power gain switched laser diodes using a novel compact picosecond switch based on a GaAs bipolar junction transistor structure for pumping

    Science.gov (United States)

    Vainshtein, Sergey; Kostamovaara, Juha

    2006-04-01

    A number of up-to-date applications, including advanced optical radars with high single-shot resolution, precise 3 D imaging, laser tomography, time imaging spectroscopy, etc., require low-cost, compact, reliable sources enabling the generation of high-power (1-100 W) single optical pulses in the picosecond range. The well-known technique of using the gain-switching operation mode of laser diodes to generate single picosecond pulses in the mW range fails to generate high-power single picosecond pulses because of a lack of high-current switches operating in the picosecond range. We report here on the achieving of optical pulses of 45W / 70ps, or alternatively 5W / 40ps, with gain-switched commercial quantum well (QW) laser diodes having emitting areas of 250 × 200 μm and 75 × 2 μm, respectively. This was made possible by the use of a novel high-current avalanche switch based on a GaAs bipolar junction transistor (BJT) structure with a switching time (transistor structure.) A simulation code developed earlier but modified and carefully verified here allowed detailed comparison of the experimental and simulated laser responses and the transient spectrum.

  8. Npn double heterostructure bipolar transistor with ingaasn base region

    Science.gov (United States)

    Chang, Ping-Chih; Baca, Albert G.; Li, Nein-Yi; Hou, Hong Q.; Ashby, Carol I. H.

    2004-07-20

    An NPN double heterostructure bipolar transistor (DHBT) is disclosed with a base region comprising a layer of p-type-doped indium gallium arsenide nitride (InGaAsN) sandwiched between n-type-doped collector and emitter regions. The use of InGaAsN for the base region lowers the transistor turn-on voltage, V.sub.on, thereby reducing power dissipation within the device. The NPN transistor, which has applications for forming low-power electronic circuitry, is formed on a gallium arsenide (GaAs) substrate and can be fabricated at commercial GaAs foundries. Methods for fabricating the NPN transistor are also disclosed.

  9. Advanced insulated gate bipolar transistor gate drive

    Science.gov (United States)

    Short, James Evans [Monongahela, PA; West, Shawn Michael [West Mifflin, PA; Fabean, Robert J [Donora, PA

    2009-08-04

    A gate drive for an insulated gate bipolar transistor (IGBT) includes a control and protection module coupled to a collector terminal of the IGBT, an optical communications module coupled to the control and protection module, a power supply module coupled to the control and protection module and an output power stage module with inputs coupled to the power supply module and the control and protection module, and outputs coupled to a gate terminal and an emitter terminal of the IGBT. The optical communications module is configured to send control signals to the control and protection module. The power supply module is configured to distribute inputted power to the control and protection module. The control and protection module outputs on/off, soft turn-off and/or soft turn-on signals to the output power stage module, which, in turn, supplies a current based on the signal(s) from the control and protection module for charging or discharging an input capacitance of the IGBT.

  10. Two-dimensional bipolar junction transistors

    Science.gov (United States)

    Gharekhanlou, Behnaz; Khorasani, Sina; Sarvari, Reza

    2014-03-01

    Recent development in fabrication technology of planar two-dimensional (2D) materials has introduced the possibility of numerous novel applications. Our recent analysis has revealed that by definition of p-n junctions through appropriate patterned doping of 2D semiconductors, ideal exponential I-V characteristics may be expected. However, the theory of 2D junctions turns out to be very different to that of standard bulk junctions. Based on this theory of 2D diodes, we construct for the first time a model to describe 2D bipolar junction transistors (2D-BJTs). We derive the small-signal equivalent model, and estimate the performance of a 2D-BJT device based on graphone as the example material. A current gain of about 138 and maximum threshold frequency of 77 GHz, together with a power-delay product of only 4 fJ per 1 μm lateral width is expected at an operating voltage of 5 V. In addition, we derive the necessary formulae and a new approximate solution for the continuity equation in the 2D configuration, which have been verified against numerical solutions.

  11. Electrical characterization of commercial NPN bipolar junction transistors under neutron and gamma irradiation

    Directory of Open Access Journals (Sweden)

    OO Myo Min

    2014-01-01

    Full Text Available Electronics components such as bipolar junction transistors, diodes, etc. which are used in deep space mission are required to be tolerant to extensive exposure to energetic neutrons and ionizing radiation. This paper examines neutron radiation with pneumatic transfer system of TRIGA Mark-II reactor at the Malaysian Nuclear Agency. The effects of the gamma radiation from Co-60 on silicon NPN bipolar junction transistors is also be examined. Analyses on irradiated transistors were performed in terms of the electrical characteristics such as current gain, collector current and base current. Experimental results showed that the current gain on the devices degraded significantly after neutron and gamma radiations. Neutron radiation can cause displacement damage in the bulk layer of the transistor structure and gamma radiation can induce ionizing damage in the oxide layer of emitter-base depletion layer. The current gain degradation is believed to be governed by the increasing recombination current in the base-emitter depletion region.

  12. Heterojunction bipolar transistor technology for data acquisition and communication

    Science.gov (United States)

    Wang, C.; Chang, M.; Beccue, S.; Nubling, R.; Zampardi, P.; Sheng, N.; Pierson, R.

    1992-01-01

    Heterojunction Bipolar Transistor (HBT) technology has emerged as one of the most promising technologies for ultrahigh-speed integrated circuits. HBT circuits for digital and analog applications, data conversion, and power amplification have been realized, with speed performance well above 20 GHz. At Rockwell, a baseline AlGaAs/GaAs HBT technology has been established in a manufacturing facility. This paper describes the HBT technology, transistor characteristics, and HBT circuits for data acquisition and communication.

  13. Unified planar process for fabricating heterojunction bipolar transistors and buried-heterostructure lasers utilizing impurity-induced disordering

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, R.L.; Mosby, W.J.; Chung, H.F.

    1988-12-26

    We describe results on a novel geometry of heterojunction bipolar transistor that has been realized by impurity-induced disordering. This structure is fabricated by a method that is compatible with techniques for the fabrication of low threshold current buried-heterostructure lasers. We have demonstrated this compatibility by fabricating a hybrid laser/transistor structure that operates as a laser with a threshold current of 6 mA at room temperature, and as a transistor with a current gain of 5.

  14. Toward complementary ionic circuits: the npn ion bipolar junction transistor.

    Science.gov (United States)

    Tybrandt, Klas; Gabrielsson, Erik O; Berggren, Magnus

    2011-07-06

    Many biomolecules are charged and may therefore be transported with ionic currents. As a step toward addressable ionic delivery circuits, we report on the development of a npn ion bipolar junction transistor (npn-IBJT) as an active control element of anionic currents in general, and specifically, demonstrate actively modulated delivery of the neurotransmitter glutamic acid. The functional materials of this transistor are ion exchange layers and conjugated polymers. The npn-IBJT shows stable transistor characteristics over extensive time of operation and ion current switch times below 10 s. Our results promise complementary chemical circuits similar to the electronic equivalence, which has proven invaluable in conventional electronic applications.

  15. Bipolar Transistors Can Detect Charge in Electrostatic Experiments

    Science.gov (United States)

    Dvorak, L.

    2012-01-01

    A simple charge indicator with bipolar transistors is described that can be used in various electrostatic experiments. Its behaviour enables us to elucidate links between 'static electricity' and electric currents. In addition it allows us to relate the sign of static charges to the sign of the terminals of an ordinary battery. (Contains 7 figures…

  16. Experiments with Charge Indicator Based on Bipolar Transistors

    Science.gov (United States)

    Dvorak, Leos; Planinsic, Gorazd

    2012-01-01

    A simple charge indicator with bipolar transistors described recently enables us to perform a number of experiments suitable for high-school physics. Several such experiments are presented and discussed in this paper as well as some features of the indicator important for its use in schools, namely its sensitivity and robustness, i.e. the…

  17. Modeling of the bipolar transistor under different pulse ionizing radiations

    Science.gov (United States)

    Antonova, A. M.; Skorobogatov, P. K.

    2017-01-01

    This paper describes a 2D model of the bipolar transistor 2T312 under gamma, X-ray and laser pulse ionizing radiations. Both the Finite Element Discretization and Semiconductor module of Comsol 5.1 are used. There is an analysis of energy deposition in this device under different radiations and the results of transient ionizing current response for some different conditions.

  18. Modeling of charge transport in ion bipolar junction transistors.

    Science.gov (United States)

    Volkov, Anton V; Tybrandt, Klas; Berggren, Magnus; Zozoulenko, Igor V

    2014-06-17

    Spatiotemporal control of the complex chemical microenvironment is of great importance to many fields within life science. One way to facilitate such control is to construct delivery circuits, comprising arrays of dispensing outlets, for ions and charged biomolecules based on ionic transistors. This allows for addressability of ionic signals, which opens up for spatiotemporally controlled delivery in a highly complex manner. One class of ionic transistors, the ion bipolar junction transistors (IBJTs), is especially attractive for these applications because these transistors are functional at physiological conditions and have been employed to modulate the delivery of neurotransmitters to regulate signaling in neuronal cells. Further, the first integrated complementary ionic circuits were recently developed on the basis of these ionic transistors. However, a detailed understanding of the device physics of these transistors is still lacking and hampers further development of components and circuits. Here, we report on the modeling of IBJTs using Poisson's and Nernst-Planck equations and the finite element method. A two-dimensional model of the device is employed that successfully reproduces the main characteristics of the measurement data. On the basis of the detailed concentration and potential profiles provided by the model, the different modes of operation of the transistor are analyzed as well as the transitions between the different modes. The model correctly predicts the measured threshold voltage, which is explained in terms of membrane potentials. All in all, the results provide the basis for a detailed understanding of IBJT operation. This new knowledge is employed to discuss potential improvements of ion bipolar junction transistors in terms of miniaturization and device parameters.

  19. InP Heterojunction Bipolar Transistor Amplifiers to 255 GHz

    Science.gov (United States)

    Radisic, Vesna; Sawdai, Donald; Scott, Dennis; Deal, William; Dang, Linh; Li, Danny; Cavus, Abdullah; To, Richard; Lai, Richard

    2009-01-01

    Two single-stage InP heterojunction bipolar transistor (HBT) amplifiers operate at 184 and 255 GHz, using Northrop Grumman Corporation s InP HBT MMIC (monolithic microwave integrated circuit) technology. At the time of this reporting, these are reported to be the highest HBT amplifiers ever created. The purpose of the amplifier design is to evaluate the technology capability for high-frequency designs and verify the model for future development work.

  20. Doping To Reduce Base Resistances Of Bipolar Transistors

    Science.gov (United States)

    Lin, True-Lon

    1991-01-01

    Modified doping profile proposed to reduce base resistance of bipolar transistors. A p/p+ base-doping profile reduces base resistance without reducing current gain. Proposed low/high base-doping profile realized by such low-temperature deposition techniques as molecular-beam epitaxy, ultra-high-vacuum chemical-vapor deposition, and limited-reaction epitaxy. Produces desired doping profiles without excessive diffusion of dopant.

  1. DEVELOPMENT OF CONTROLLED RECTIFIERS BASED ON THE BIPOLAR WITH STATIC INDUCTION TRANSISTORS (BSIT

    Directory of Open Access Journals (Sweden)

    F. I. Bukashev

    2016-01-01

    Full Text Available Aim. The aim of this study is to develop one of the most perspective semiconductor device suitable for creation and improvement of controlled rectifiers, bipolar static induction transistor.Methods. Considered are the structural and schematic circuit controlled rectifier based on bipolar static induction transistor (BSIT, and the criterion of effectiveness controlled rectifiers - equivalent to the voltage drop.Results. Presented are the study results of controlled rectifier layout on BSIT KT698I. It sets the layout operation at an input voltage of 2.0 V at a frequency up to 750 kHz. The efficiency of the studied layouts at moderate current densities as high as 90 % .Offered is optimization of technological route microelectronic controlled rectifier manufacturing including BSIT and integrated bipolar elements of the scheme management.Conclusion. It is proved that the most efficient use of the bipolar static induction transistor occurs at the low voltage controlled rectifiers 350-400 kHz, at frequencies in conjunction with a low-voltage control circuit.It is proved that the increase of the functional characteristics of the converters is connected to the expansion of the input voltage and output current ranges

  2. Wide bandgap collector III-V double heterojunction bipolar transistors

    International Nuclear Information System (INIS)

    Flitcroft, R.M.

    2000-10-01

    This thesis is devoted to the study and development of Heterojunction Bipolar Transistors (HBTs) designed for high voltage operation. The work concentrates on the use of wide bandgap III-V semiconductor materials as the collector material and their associated properties influencing breakdown, such as impact ionisation coefficients. The work deals with issues related to incorporating a wide bandgap collector into double heterojunction structures such as conduction band discontinuities at the base-collector junction and results are presented which detail, a number of methods designed to eliminate the effects of such discontinuities. In particular the use of AlGaAs as the base material has been successful in eliminating the conduction band spike at this interface. A method of electrically injecting electrons into the collector has been employed to investigate impact ionisation in GaAs, GaInP and AlInP which has used the intrinsic gain of the devices to extract impact ionisation coefficients over a range of electric fields beyond the scope of conventional optical injection techniques. This data has enabled the study of ''dead space'' effects in HBT collectors and have been used to develop an analytical model of impact ionisation which has been incorporated into an existing Ebers-Moll HBT simulator. This simulator has been shown to accurately reproduce current-voltage characteristics in both the devices used in this work and for external clients. (author)

  3. Implantation-Free 4H-SiC Bipolar Junction Transistors with Double Base Epi-layers

    Science.gov (United States)

    2007-05-14

    junction transistor ( BJT ) which is completely free of ion implantation and hence is free of the implantation- induced crystal damages and high-temperature...Index Terms—Silicon carbide, bipolar junction transistors ( BJTs ), power transistors ...Std Z39-18 I. INTRODUCTION 4H-SiC bipolar junction transistor ( BJT ) is an important switching device for high power and high temperature

  4. Single-event burnout of power bipolar junction transistors

    International Nuclear Information System (INIS)

    Titus, J.L.; Johnson, G.H.; Schrimpf, R.D.; Galloway, K.F.

    1991-01-01

    Experimental evidence of single-event burnout of power bipolar junctions transistors (BJTs) is reported for the first time. Several commercial power BJTs were characterized in a simulated cosmic ray environment using mono-energetic ions at the tandem Van de Graaff accelerator facility at Brookhaven National Laboratory. Most of the device types exposed to this simulated environment exhibited burnout behavior. In this paper the experimental technique, data, and results are presented, while a qualitative model is used to help explain those results and trends observed in this experiment

  5. The effects of gamma irradiation on neutron displacement sensitivity of lateral PNP bipolar transistors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chenhui, E-mail: wangchenhui@nint.ac.cn; Chen, Wei; Liu, Yan; Jin, Xiaoming; Yang, Shanchao; Qi, Chao

    2016-09-21

    The effects of gamma irradiation on neutron displacement sensitivity of four types of lateral PNP bipolar transistors (LPNPs) with different neutral base widths, emitter widths and the doping concentrations of the epitaxial base region are studied. The physical mechanisms of the effects are explored by defect analysis using deep level transient spectroscopy (DLTS) techniques and numerical simulations of recombination process in the base region of the lateral PNP bipolar transistors, and are verified by the experiments on gate-controlled lateral PNP bipolar transistors (GCLPNPs) manufactured in the identical commercial bipolar process with different gate bias voltage. The results indicate that gamma irradiation increases neutron displacement damage sensitivity of lateral PNP bipolar transistors and the mechanism of this phenomenon is that positive charge induced by gamma irradiation enhances the recombination process in the defects induced by neutrons in the base region, leading to larger recombination component of base current and greater gain degradation.

  6. Bipolar junction transistor models for circuit simulation of cosmic-ray-induced soft errors

    Science.gov (United States)

    Benumof, R.; Zoutendyk, J.

    1984-01-01

    This paper examines bipolar junction transistor models suitable for calculating the effects of large excursions of some of the variables determining the operation of a transistor. Both the Ebers-Moll and Gummel-Poon models are studied, and the junction and diffusion capacitances are evaluated on the basis of the latter model. The most interesting result of this analysis is that a bipolar junction transistor when struck by a cosmic particle may cause a single event upset in an electronic circuit if the transistor is operated at a low forward base-emitter bias.

  7. ESTIMATION OF THERMAL PARAMETERS OF POWER BIPOLAR TRANSISTORS BY THE METHOD OF THERMAL RELAXATION DIFFERENTIAL SPECTROMETRY

    Directory of Open Access Journals (Sweden)

    V. S. Niss

    2015-01-01

    Full Text Available Thermal performance of electronic devices determines the stability and reliability of the equipment. This leads to the need for a detailed thermal analysis of semiconductor devices. The goal of the work is evaluation of thermal parameters of high-power bipolar transistors in plastic packages TO-252 and TO-126 by a method of thermal relaxation differential spectrometry. Thermal constants of device elements and distribution structure of thermal resistance defined as discrete and continuous spectra using previously developed relaxation impedance spectrometer. Continuous spectrum, based on higher-order derivatives of the dynamic thermal impedance, follows the model of Foster, and discrete to model of Cauer. The structure of sample thermal resistance is presented in the form of siх-chain electro-thermal RC model. Analysis of the heat flow spreading in the studied structures is carried out on the basis of the concept of thermal diffusivity. For transistor structures the area and distribution of the heat flow cross-section are determined. On the basis of the measurements the thermal parameters of high-power bipolar transistors is evaluated, in particular, the structure of their thermal resistance. For all of the measured samples is obtained that the thermal resistance of the layer planting crystal makes a defining contribution to the internal thermal resistance of transistors. In the transition layer at the border of semiconductor-solder the thermal resistance increases due to changes in the mechanism of heat transfer. Defects in this area in the form of delamination of solder, voids and cracks lead to additional growth of thermal resistance caused by the reduction of the active square of the transition layer. Method of thermal relaxation differential spectrometry allows effectively control the distribution of heat flow in high-power semiconductor devices, which is important for improving the design, improve the quality of landing crystals of power

  8. Heterojunction Bipolar Transistor Power Amplifiers for Long-Range X-band Communications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — In this SBIR Phase I project, Vega Wave Systems, Inc. will develop and demonstrate a novel InGaP-GaAs heterojunction bipolar transistor power amplifier for...

  9. Silicon Nanomembrane Bipolar Junction Transistors for Microwave Frequency Applications

    Science.gov (United States)

    Bavier, John; Ballarotto, Vince; Cumings, John

    2014-03-01

    Silicon nanomembranes (SiNMs) are a promising material for flexible semiconductor devices due to their high carrier mobility and compatibility with standard CMOS processing. Previous studies have reported SiNM field-effect transistors with operating frequencies as high as 12 GHz. In order to expand the utility of SiNM devices, a method for the fabrication of monocrystalline microwave frequency silicon bipolar junction transistors (BJTs) will be presented. High-temperature processing of SiNM BJT devices is performed on a Silicon-on-Insulator (SOI) wafer. Using angled ion implantation, conformal chemical vapor deposition and anisotropic reactive ion etching, a poly-silicon sidewall spacer is formed. This spacer defines a base region approximately 200nm wide without the use of electron beam lithography. Devices are then released using selective wet etching in HF and transferred to alternate flexible substrates. Microwave frequency data will be presented, and the effects of the transfer process on device performance will be discussed.

  10. Neutron effects on the electrical and switching characteristics of NPN bipolar power transistors

    Science.gov (United States)

    Frasca, Albert J.; Schwarze, Gene E.

    1988-01-01

    The use of nuclear reactors to generate electrical power for future space missions will require the electrical components used in the power conditioning, control, and transmission subsystem to operate in the associated radiation environments. An initial assessment of neutron irradiation on the electrical and switching characteristics of commercial high power NPN bipolar transistors was investigated. The results clearly show the detrimental effects caused by neutron irradiation on the electrical and switching characteristics of the NPN bipolar power transistor.

  11. Total dose and dose rate models for bipolar transistors in circuit simulation.

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Phillip Montgomery; Wix, Steven D.

    2013-05-01

    The objective of this work is to develop a model for total dose effects in bipolar junction transistors for use in circuit simulation. The components of the model are an electrical model of device performance that includes the effects of trapped charge on device behavior, and a model that calculates the trapped charge densities in a specific device structure as a function of radiation dose and dose rate. Simulations based on this model are found to agree well with measurements on a number of devices for which data are available.

  12. Laser Pulse Tests of Bipolar Junction Transistors (BJTs) for SET Analysis

    Science.gov (United States)

    Daniel, C.; Plettner, C.; Poivey, C.; Schuttauf, A.; Tonicello, F.; Triggianese, M.

    2014-08-01

    In order to study the Single Event Transient (SET) sensitivity of discrete bipolar junction transistors, laser tests conducted at EADS Innovation Works in Sureness are presented and discussed. A number of different BJT samples have been tested in different operating conditions. The tests demonstrate that: discrete BJTs are indeed sensitive to collected charge; the most sensitive region is the collector/base junctions and that the different internal structure gives different SET shapes. We present measurements, simulation and comparison for SET modeled in PSPICE and tested with a laser.

  13. Optimization of base-to-emitter spacer thickness to maximize the frequency response of bipolar transistors

    Science.gov (United States)

    Lee, Wai-Kit; Chan, Alain C. K.; Chan, Mansun

    2005-04-01

    The impacts of base-to-emitter spacer thickness on the unity gain frequency ( fT), base resistance ( rB), base collector capacitance ( CBC) and maximum oscillation frequency ( fmax) of a bipolar junction transistor (BJT) are studied. Using the extracted Y-parameters from a simulated device with structural parameters calibrated to an actual process, the resulting fT and fmax with different spacer thickness is reported. A tradeoff between peak fT and fmax is observed and the process window to obtain high fT and fmax is proposed.

  14. Performance enhancement of a heterojunction bipolar transistor (HBT) by two-step passivation

    International Nuclear Information System (INIS)

    Fu, S.-I.; Lai, P.-H.; Tsai, Y.-Y.; Hung, C.-W.; Yen, C.-H.; Cheng, S.-Y.; Liu, W.-C.

    2006-01-01

    An interesting two-step passivation (with ledge structure and sulphide based chemical treatment) on base surface, for the first time, is demonstrated to study the temperature-dependent DC characteristics and noise performance of an InGaP/GaAs heterojunction bipolar transistor (HBT). Improved transistor behaviors on maximum current gain β max , offset voltage ΔV CE , and emitter size effect are obtained by using the two-step passivation. Moreover, the device with the two-step passivation exhibits relatively temperature-independent and improved thermal stable performances as the temperature is increased. Therefore, the two-step passivationed device can be used for high-temperature and low-power electronics applications

  15. Electrical coupling of single cardiac rat myocytes to field-effect and bipolar transistors.

    Science.gov (United States)

    Kind, Thomas; Issing, Matthias; Arnold, Rüdiger; Müller, Bernt

    2002-12-01

    A novel bipolar transistor for extracellular recording the electrical activity of biological cells is presented, and the electrical behavior compared with the field-effect transistor (FET). Electrical coupling is examined between single cells separated from the heart of adults rats (cardiac myocytes) and both types of transistors. To initiate a local extracellular voltage, the cells are periodically stimulated by a patch pipette in voltage clamp and current clamp mode. The local extracellular voltage is measured by the planar integrated electronic sensors: the bipolar and the FET. The small signal transistor currents correspond to the local extracellular voltage. The two types of sensor transistors used here were developed and manufactured in the laboratory of our institute. The manufacturing process and the interfaces between myocytes and transistors are described. The recordings are interpreted by way of simulation based on the point-contact model and the single cardiac myocyte model.

  16. Complementary vertical bipolar transistor process using high-energy ion implantation

    NARCIS (Netherlands)

    Ragay, F.W.; Ragay, F.W.; Aarnink, Antonius A.I.; Wallinga, Hans

    1991-01-01

    High-energy ion implantation is used as a key processing step in the formation of a complementary bipolar process with both transistor types being vertical. Both n-p-n and p -n-p transistors are made vertically with a deep implanted collector region. Combinations of epitaxial and buried layers are

  17. T-shaped emitter metal heterojunction bipolar transistors for submillimeter wave applications

    Science.gov (United States)

    Fung, Andy; Samoska, Lorene; Velebir, Jim; Siege, Peter; Rodwell, Mark; Paidi, Vamsi; Griffth, Zach; Urteaga, Miguel; Malik, Roger

    2004-01-01

    We report on the development of submillimeter wave transistors at JPL. The goal of the effort is to produce advance-reliable high frequency and high power amplifiers, voltage controlled oscillators, active multipliers, and high-speed mixed-signal circuits for space borne applications. The technology in development to achieve this is based on the Indium Phosphide (InP) Heterojunction Bipolar Transistor (HBT). The HBT is well suited for high speed, high power and uniform (across wafer) performance, due to the ability to tailor the material structure that electrons traverse through by well-controlled epitaxial growth methods. InP with its compatible lattice matched alloys such as indium gallium arsenide (InGaAs) and indium aluminium arsenide (InAlAs) provides for high electron velocities and high voltage breakdown capabilities. The epitaxial methods for this material system are fairly mature, however the implementation of high performance and reliable transistors are still under development by many laboratories. Our most recently fabricated, second generation mesa HBTs at JPL have extrapolated current gain cutoff frequency (FJ of 142GHz and power gain cutoff frequency (Fm,) of approximately 160GHz. This represents a 13% and 33% improvement of Ft and F, respectively, compared to the first generation mesa HBTs [l]. Analysis based on the University of California, Santa Barbara (UCSB) device model, RF device characteristics can be significantly improved by reducing base contact resistance and base metal contact width. We will describe our effort towards increasing transistor performance and yield.

  18. Radiation induced deep level defects in bipolar junction transistors under various bias conditions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chaoming; Yang, Jianqun [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Li, Xingji, E-mail: lxj0218@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Ma, Guoliang [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Xiao, Liyi [Department of Astronautics, Harbin Institute of Technology, Harbin 150001 (China); Bollmann, Joachim [Institute of Electronics and Sensor Materials, TU Bergakademie Freiberg, 71691 (Germany)

    2015-12-15

    Bipolar junction transistor (BJT) is sensitive to ionization and displacement radiation effects in space. In this paper, 35 MeV Si ions were used as irradiation source to research the radiation damage on NPN and PNP bipolar transistors. The changing of electrical parameters of transistors was in situ measured with increasing irradiation fluence of 35 MeV Si ions. Using deep level transient spectroscopy (DLTS), defects in the bipolar junction transistors under various bias conditions are measured after irradiation. Based on the in situ electrical measurement and DLTS spectra, it is clearly that the bias conditions can affect the concentration of deep level defects, and the radiation damage induced by heavy ions.

  19. Radiation induced deep level defects in bipolar junction transistors under various bias conditions

    Science.gov (United States)

    Liu, Chaoming; Yang, Jianqun; Li, Xingji; Ma, Guoliang; Xiao, Liyi; Bollmann, Joachim

    2015-12-01

    Bipolar junction transistor (BJT) is sensitive to ionization and displacement radiation effects in space. In this paper, 35 MeV Si ions were used as irradiation source to research the radiation damage on NPN and PNP bipolar transistors. The changing of electrical parameters of transistors was in situ measured with increasing irradiation fluence of 35 MeV Si ions. Using deep level transient spectroscopy (DLTS), defects in the bipolar junction transistors under various bias conditions are measured after irradiation. Based on the in situ electrical measurement and DLTS spectra, it is clearly that the bias conditions can affect the concentration of deep level defects, and the radiation damage induced by heavy ions.

  20. Physical processes of current gain in InAs bipolar junction transistors

    Science.gov (United States)

    Wu, X.; Averett, K. L.; Maimon, S.; Koch, M. W.; Wicks, G. W.

    2004-01-01

    InAs bipolar junction transistors (BJTs), grown by molecular beam epitaxy, are reported with common emitter current gains ( β's) as large as 400. The factors affecting the common emitter current gain have been studied by estimating the magnitudes of the base transport factor ( αT) and emitter injection efficiency ( γ). This has been accomplished by studying a sequence of InAs BJTs with varying emitter doping densities, NE. Minority carrier diffusion length in the base ( LB), αT, and γ have been extracted from measured electrical characteristics. The results of the study of these InAs BJTs are as follows: L B≈0.4 μm, αT≈98% and γ ranges from 92% to nearly 100% depending on NE. This knowledge of the magnitudes of the injection efficiencies suggests when it would be useful to move from the simple BJT structure to the more advanced heterojunction bipolar transistor (HBT) structure. Lower γ BJTs would be improved, however high- γ BJTs would benefit little, by the use of the widegap emitters of HBTs. The method developed here to estimate γ, αT and LB is not specific to InAs BJTs, but should be useful for study of BJTs and HBTs in any material system.

  1. Comparison between Field Effect Transistors and Bipolar Junction Transistors as Transducers in Electrochemical Sensors

    Science.gov (United States)

    Zafar, Sufi; Lu, Minhua; Jagtiani, Ashish

    2017-01-01

    Field effect transistors (FET) have been widely used as transducers in electrochemical sensors for over 40 years. In this report, a FET transducer is compared with the recently proposed bipolar junction transistor (BJT) transducer. Measurements are performed on two chloride electrochemical sensors that are identical in all details except for the transducer device type. Comparative measurements show that the transducer choice significantly impacts the electrochemical sensor characteristics. Signal to noise ratio is 20 to 2 times greater for the BJT sensor. Sensitivity is also enhanced: BJT sensing signal changes by 10 times per pCl, whereas the FET signal changes by 8 or less times. Also, sensor calibration curves are impacted by the transducer choice. Unlike a FET sensor, the calibration curve of the BJT sensor is independent of applied voltages. Hence, a BJT sensor can make quantitative sensing measurements with minimal calibration requirements, an important characteristic for mobile sensing applications. As a demonstration for mobile applications, these BJT sensors are further investigated by measuring chloride levels in artificial human sweat for potential cystic fibrosis diagnostic use. In summary, the BJT device is demonstrated to be a superior transducer in comparison to a FET in an electrochemical sensor.

  2. Silicon Germanium Heterojunction Bipolar Transistor for Digital Application

    Directory of Open Access Journals (Sweden)

    Engelin Shintadewi Julian

    2012-09-01

    Full Text Available Bipolar transistor performances can be characterized by figures of merit such as cutoff frequency, maximum frequency of oscillation and ECL gate delay. We studied the required figures of merit for digital application and the effects of lateral and vertical scaling to the figures of merit of SiGe HBT. With lateral scaling, the width of emitter finger is scaled down from 0.25 to 0.12 ?m while with the vertical scaling, the base width is scaled down to reduce the base delay. We also observed the effects of Ge profile and Ge fraction to the devices performances. Bipole3 5.3.1G is used to help us in the study. We found that high frequency cutoff and maximum frequency of oscillation as well as low ECL gate delay are all important for digital applications. Scaling down the emitter finger width enhanced the maximum frequency of oscillation and reduced ECL gate delay significantly while scaling down the base width increased the cutoff frequency and current gain.

  3. Effect of temperature on the performance of a bipolar transistor carrier-injected optical waveguide modulator/switch.

    Science.gov (United States)

    Okada, Y

    1991-05-15

    The effect of ambient temperature on the performance of a GaAs/AlGaAs heterojunction bipolar transistor waveguide structure carrier-injected optical intensity modulator/switch is discussed. An increase in the temperature increases the achievable optical modulation ratio at the expense of increased absorption loss, and vice versa. Analysis also shows that for practical use a tolerable temperature change should be no more than approximately 10 degrees C.

  4. Composition and doping control for metal-organic chemical vapor deposition of InP-based double heterojunction bipolar transistor with hybrid base structure consisting of GaAsSb contact and InGaAsSb graded layers

    Science.gov (United States)

    Hoshi, Takuya; Kashio, Norihide; Sugiyama, Hiroki; Yokoyama, Haruki; Kurishima, Kenji; Ida, Minoru; Matsuzaki, Hideaki

    2017-07-01

    We report on a method for composition and doping control for metalorganic chemical vapor deposition of a double heterojunction bipolar transistor (DHBT) with a hybrid base structure consisting of a compositionally graded InGaAsSb for boosting an average electron velocity and a heavily doped thin GaAsSb for lowering the base contact resistivity. The GaAsSb contact layer can be formed by simply turning off the supply of In precursor tetramethylindium (TMIn) after the growth of the composition and doping graded InGaAsSb base. Consequently, the solid composition and hole concentration of hybrid base can be properly controlled by just modulating the supply of only TMIn and carbon tetrabromide. Secondary ion mass spectroscopy for the DHBT wafer reveals that the contents of In, Ga, and C inside the base are actually modulated from the collector side to the emitter side as expected. Transmission-line-model measurements were performed for the compositionally graded-InGaAsSb/GaAsSb hybrid base. The contact resistivity is estimated to be 5.3 Ω µm2, which is lower than half the value of a compositionally graded InGaAsSb base without the GaAsSb contact layer. The results indicate that the compositionally-graded-InGaAsSb/GaAsSb-contact hybrid base structure grown by this simple method is very advantageous for obtaining DHBTs with a very high maximum oscillation frequency.

  5. GaAs vapor-grown bipolar transistors.

    Science.gov (United States)

    Nuese, C. J.; Gannon, J. J.; Dean, R. H.; Gossenberger, H. F.; Enstrom, R. E.

    1972-01-01

    Discussion of an approach for the fabrication of high-temperature GaAs transistors which is centered on the preparation of n-p-n three-layered structures entirely by a vapor-phase growth technique, as described by Tietjen and Amick (1966). The low growth temperature of approximately 750 C is thought to reduce contamination during crystal growth and to contribute to the reasonably high minority-carrier lifetimes obtained for the vapor-grown p-n junctions. The fact that impurity concentrations and layer thicknesses can be precisely controlled for epitaxial layers as thin as 1 micrometer is an important feature of this growth technique.

  6. Validation of Nonlinear Bipolar Transistor Model by Small-Signal Measurements

    DEFF Research Database (Denmark)

    Vidkjær, Jens; Porra, V.; Zhu, J.

    1992-01-01

    A new method for the validity analysis of nonlinear transistor models is presented based on DC-and small-signal S-parameter measurements and realistic consideration of the measurement and de-embedding errors and singularities of the small-signal equivalent circuit. As an example, some analysis...... results for an extended Gummel Poon model are presented in the case of a UHF bipolar power transistor....

  7. Silicon on insulator bipolar junction transistors for flexible microwave applications

    Science.gov (United States)

    Bavier, John McGoldrick

    Microwave frequency flexible electronic devices require a high quality semiconducting material and a set of fabrication techniques that are compatible with device integration onto flexible polymer substrates. Over the past ten years, monocrystalline silicon nanomembranes (SiNMs) have been studied as a flexible semiconducting material that is compatible with industrial Si processing. Fabricated from commercial silicon on insulator (SOI) wafers, SiNMs can be transferred to flexible substrates using a variety of techniques. Due to their high carrier mobilities, SiNMs are a promising candidate for flexible microwave frequency devices. This dissertation presents fabrication techniques for flexible SiNM devices in general, as well as the progress made towards the development of a microwave frequency SiNM bipolar junction transistor (BJT). In order to overcome previous limitations associated with adhesion, novel methods for transfer printing of metal films and SiNMs are presented. These techniques enable transfer printing of a range of metal films and improve the alignment of small transfer printed SiNM devices. Work towards the development of a microwave frequency BJT on SOI for SiNM devices is also described. Utilizing a self-aligned polysilicon sidewall spacer technique, a BJT with an ultra-narrow base region is fabricated and tested. Two regimes of operation are identified and characterized under DC conditions. At low base currents, devices exhibited forward current gain as high as betaF = 900. At higher base current values, a transconductance of 59 mS was observed. Microwave scattering parameters were obtained for the BJTs under both biasing conditions and compared to unbiased measurements. Microwave frequency gain was not observed. Instead, bias-dependent non-reciprocal behavior was observed and examined. Limitations associated with the microwave impedance-matched electrode configuration are presented. High current densities in the narrow electrodes cause localized

  8. 4H-SiC Power Bipolar Junction Transistor with a Very Low Specific On-resistance of 2.9 mOmega.cm2

    Science.gov (United States)

    2006-04-12

    specific on-resistance (Rsp,on) of power 4H-SiC bipolar junction transistors ( BJT ). A 4H-SiC BJT based on a 12 um drift-layer shows a record low...reported for high power 4H-SiC BJTs . Index Terms—Silicon carbide, bipolar junction transistors ( BJTs ), power transistors ...bipolar junction transistor ( BJT ) is an important switching device for high power and high temperature applications, which is an intrinsically

  9. Bipolar transistor with lateral emitter and collector and method of production

    NARCIS (Netherlands)

    Hueting, Raymond Josephus Engelbart; van den Oever, Leon C.M.

    2016-01-01

    A bipolar transistor includes a substrate of semiconductor material, a high-mobility layer in the substrate, and a donor layer adjacent to the high-mobility layer. An emitter terminal forms an emitter contact on the donor layer, and a collector terminal forms a collector contact on the donor layer.

  10. Using Animation to Improve the Students' Academic Achievement on Bipolar Junction Transistor

    Science.gov (United States)

    Zoabi, W.; Sabag, N.; Gero, A.

    2012-01-01

    Teaching abstract subjects to students studying towards a degree in electronics practical engineering (a degree between a technician and an engineer) requires didactic tools that enable understanding of issues without using advanced mathematics and physics. One basic issue is the BJT (Bipolar Junction Transistor) that requires preliminary…

  11. Modeling of the collector epilayer of a bipolar transistor in the MEXTRAM model

    NARCIS (Netherlands)

    de Graaff, H.C.; de Graaff, H.C.; Kloosterman, W.J.

    1995-01-01

    A new model description for the behaviour of epitaxial collectors in bipolar transistors is given. This is part of MEXTRAM, a compact model for circuit simulation, and it gives the voltage drop and stored minority carrier charge in the collector epilayer as a function of the bias conditions. It

  12. Lateral PNP bipolar transistor with aiding field diffusions

    Science.gov (United States)

    Gallagher, R. C.; Mc Cann, D. H.

    1969-01-01

    Fabrication technique produces field aided lateral PNP transistors compatible with micropower switching circuits. The sub-collector diffusion is performed with phosphorus as the dopant and the epitaxy is grown using the higher temperature silicon tetrachloride process.

  13. Transferred substrate heterojunction bipolar transistors for submillimeter wave applications

    Science.gov (United States)

    Fung, A.; Samoska, L.; Siegel, P.; Rodwell, M.; Urteaga, M.; Paidi, V.

    2003-01-01

    We present ongoing work towards the development of submillimeter wave transistors with goals of realizing advanced high frequency amplifiers, voltage controlled oscillators, active multipliers, and traditional high-speed digital circuits.

  14. Influence of layout design and on-wafer heatspreaders on the thermal behavior of fully-isolated bipolar transistors: Part I - Static analysis

    Science.gov (United States)

    Russo, Salvatore; Spina, Luigi La; d'Alessandro, Vincenzo; Rinaldi, Niccolò; Nanver, Lis K.

    2010-08-01

    The impact of layout parameters on the steady-state thermal behavior of bipolar junction transistors (BJTs) with full dielectric isolation is extensively analyzed by accurate DC measurements and 3-D numerical simulations. The influence of the aspect ratio of the emitter stripe, as well as the consequences of device scaling, are investigated from a thermal viewpoint. Furthermore, the beneficial effect of implementing aluminum nitride (AlN) thin-film heatspreaders is examined. It is shown that the silicon area surrounding the heat source, as well as the distance to high-thermal-conductivity regions, can have a significant impact on the thermal behavior. A recently proposed scaling rule for the thermal resistance - fully compatible with advanced transistor models - is successfully applied to a series of test BJT structures provided that a simple parameter optimization is carried out. Based on this, some generally applicable guidelines are given to effectively downscale fully-isolated bipolar transistors without significantly worsening the thermal issues.

  15. Low-frequency noise behavior of polysilicon emitter bipolar junction transistors: a review

    Science.gov (United States)

    Deen, M. Jamal; Pascal, Fabien

    2003-05-01

    For many analog integrated circuit applications, the polysilicon emitter bipolar junction transistor (PE-BJT) is still the preferred choice because of its higher operational frequency and lower noise performance characteristics compared to MOS transistors of similar active areas and at similar biasing currents. In this paper, we begin by motivating the reader with reasons why bipolar transistors are still of great interest for analog integrated circuits. This motivation includes a comparison between BJT and the MOSFET using a simple small-signal equivalent circuit to derive important parameters that can be used to compare these two technologies. An extensive review of the popular theories used to explain low frequency noise results is presented. However, in almost all instances, these theories have not been fully tested. The effects of different processing technologies and conditions on the noise performance of PE-BJTs is reviewed and a summary of some of the key technological steps and device parameters and their effects on noise is discussed. The effects of temperature and emitter geometries scaling is reviewed. It is shown that dispersion of the low frequency noise in ultra-small geometries is a serious issue since the rate of increase of the noise dispersion is faster than the noise itself as the emitter geometry is scaled to smaller values. Finally, some ideas for future research on PE-BJTs, some of which are also applicable to SiGe heteorjunction bipolar transistors and MOSFETs, are presented after the conclusions.

  16. The free electron gas primary thermometer using an ordinary bipolar junction transistor approaches ppm accuracy

    Science.gov (United States)

    Mimila-Arroyo, J.

    2017-06-01

    In this paper, it is demonstrated that the free electron gas primary thermometer based on a bipolar junction transistor is able to provide the temperature with an accuracy of a few parts per million. Its simple functioning principle exploits the behavior of the collector current when properly biased to extract the temperature. Using general purpose silicon transistors at the water triple point (273.16 K) and gallium melting point (302.9146), an accuracy of a few parts per million has been reached, constituting the simplest and the easiest to operate primary thermometer, that might be considered even for the redefinition of Kelvin.

  17. Long-Term Reliability of High Speed SiGe/Si Heterojunction Bipolar Transistors

    Science.gov (United States)

    Ponchak, George E. (Technical Monitor); Bhattacharya, Pallab

    2003-01-01

    Accelerated lifetime tests were performed on double-mesa structure Si/Si0.7Ge0.3/Si npn heterojunction bipolar transistors, grown by molecular beam epitaxy, in the temperature range of 175C-275C. Both single- and multiple finger transistors were tested. The single-finger transistors (with 5x20 micron sq m emitter area) have DC current gains approximately 40-50 and f(sub T) and f(sub MAX) of up to 22 GHz and 25 GHz, respectively. The multiple finger transistors (1.4 micron finger width, 9 emitter fingers with total emitter area of 403 micron sq m) have similar DC current gain but f(sub T) of 50 GHz. It is found that a gradual degradation in these devices is caused by the recombination enhanced impurity diffusion (REID) of boron atoms from the p-type base region and the associated formation of parasitic energy barriers to electron transport from the emitter to collector layers. This REID has been quantitatively modeled and explained, to the first order of approximation, and the agreement with the measured data is good. The mean time to failure (MTTF) of the devices at room temperature is estimated from the extrapolation of the Arrhenius plots of device lifetime versus reciprocal temperature. The results of the reliability tests offer valuable feedback for SiGe heterostructure design in order to improve the long-term reliability of the devices and circuits made with them. Hot electron induced degradation of the base-emitter junction was also observed during the accelerated lifetime testing. In order to improve the HBT reliability endangered by the hot electrons, deuterium sintered techniques have been proposed. The preliminary results from this study show that a deuterium-sintered HBT is, indeed, more resistant to hot-electron induced base-emitter junction degradation. SiGe/Si based amplifier circuits were also subjected to lifetime testing and we extrapolate MTTF is approximately 1.1_10(exp 6) hours at 125iC junction temperature from the circuit lifetime data.

  18. Employment Of IGBT-Transistors For Bipolar Impulsed Micro-Arc Oxidation

    Directory of Open Access Journals (Sweden)

    Krainyukov Alexander

    2015-09-01

    Full Text Available The paper is devoted to the use of insulated gate bipolar transistors (IGBT for the micro-arc oxidation (MAO process. The technical requirements to the current switches of power supplies for the pulsed bipolar MAO technology have been developed. The research installation for investigating the IGBT commutation processes during the pulse anode-cathode oxidation has been constructed. The experiments have been performed with its help in order to estimate the possibility of using half-bridge IGBT-modules with different drivers. The research results of the commutation processes investigation for different IGBT half- bridge modules are presented.

  19. The Role of the Silicon Germanium (SiGe) Heterojunction Bipolar Transistor (HBT) in Mobile Technology Platforms

    Science.gov (United States)

    2011-09-01

    1. Comparison of transistor cutoff frequency for a Si BJT and SiGe HBT over time (1...the characteristics of a SiGe HBT, and compares how SiGe fares in the worlds of the GaAs HBT and the Si bipolar junction transistors ( BJT ). 2...supremacy of the Si BJT or field effect transistor (FET) in most applications. These properties include (1) growth of comparably large Si wafers with

  20. Bipolar Junction Transistors in Two-Dimensional WSe2 with Large Current and Photocurrent Gains.

    Science.gov (United States)

    Agnihotri, Pratik; Dhakras, Prathamesh; Lee, Ji Ung

    2016-07-13

    In the development of semiconductor devices, the bipolar junction transistor (BJT) features prominently as being the first solid state transistor that helped to usher in the digital revolution. For any new semiconductor, therefore, the fabrication and characterization of the BJT are important for both technological importance and historical significance. Here, we demonstrate a BJT device in exfoliated TMD semiconductor WSe2. We use buried gates to electrostatically create doped regions with back-to-back p-n junctions. We demonstrate two central characteristics of a bipolar device: current gain when operated as a BJT and a photocurrent gain when operated as a phototransistor. We demonstrate a current gain of 1000 and photocurrent gain of 40 and describe features that enhance these properties due to the doping technique that we employ.

  1. 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.

  2. 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.

  3. Thermal Simulation of Switching Pulses in an Insulated Gate Bipolar Transistor (IGBT) Power Module

    Science.gov (United States)

    2015-02-01

    prepared with SolidWorks computer-aided design software. The module has 8 silicon IGBTs mounted on copper (Cu) lands bonded onto a dielectric circuit...aluminum nitride ARL US Army Research Laboratory Cu copper IGBT insulated gate bipolar transistor ms millisecond 3D 3-dimensional W watt...RDRL CIO LL TECHL LIB 1 GOVT PRNTG OFC (PDF) ATTN A MALHOTRA 5 US ARMY RSRCH LAB (PDF) ATTN RDRL SED C W TIPTON ATTN RDRL SED P D

  4. Experimental DC extraction of the thermal resistance of bipolar transistors taking into account the Early effect

    Science.gov (United States)

    d'Alessandro, Vincenzo

    2017-01-01

    This paper presents three methods to experimentally extract the thermal resistance of bipolar transistors taking into account the Early effect. The approaches are improved variants of recently-proposed techniques relying on common-base DC measurements. The accuracy is numerically verified by making use of a compact model calibrated on I-V characteristics of state-of-the-art SOG BJTs and SiGe:C HBTs.

  5. Verification of the Simultaneous Local Extraction Method of Base and Thermal Resistance of Bipolar Transistors

    OpenAIRE

    Robert Setekera; Luuk Tiemeijer; Ramses van der Toorn

    2014-01-01

    In this paper an extensive verification of the extraction method (published earlier) that consistently accounts for self-heating and Early effect to accurately extract both base and thermal resistance of bipolar junction transistors is presented. The method verification is demonstrated on advanced RF SiGe HBTs were the extracted results for the thermal resistance are compared with those from another published method that ignores the effect of Early effect on internal base...

  6. Atomic-Monolayer Two-Dimensional Lateral Quasi-Heterojunction Bipolar Transistors with Resonant Tunneling Phenomenon

    KAUST Repository

    Lin, Che-Yu

    2017-10-04

    High-frequency operation with ultra-thin, lightweight and extremely flexible semiconducting electronics are highly desirable for the development of mobile devices, wearable electronic systems and defense technologies. In this work, the first experimental observation of quasi-heterojunction bipolar transistors utilizing a monolayer of the lateral WSe2-MoS2 junctions as the conducting p-n channel is demonstrated. Both lateral n-p-n and p-n-p heterojunction bipolar transistors are fabricated to exhibit the output characteristics and current gain. A maximum common-emitter current gain of around 3 is obtained in our prototype two-dimensional quasi-heterojunction bipolar transistors. Interestingly, we also observe the negative differential resistance in the electrical characteristics. A potential mechanism is that the negative differential resistance is induced by resonant tunneling phenomenon due to the formation of quantum well under applying high bias voltages. Our results open the door to two-dimensional materials for high-frequency, high-speed, high-density and flexible electronics.

  7. Experimental Analysis of Proton-Induced Displacement and Ionization Damage Using Gate-Controlled Lateral PNP Bipolar Transistors

    Science.gov (United States)

    Ball, D. R.; Schrimpf, R. D.; Barnaby, H. J.

    2006-01-01

    The electrical characteristics of proton-irradiated bipolar transistors are affected by ionization damage to the insulating oxide and displacement damage to the semiconductor bulk. While both types of damage degrade the transistor, it is important to understand the mechanisms individually and to be able to analyze them separately. In this paper, a method for analyzing the effects of ionization and displacement damage using gate-controlled lateral PNP bipolar junction transistors is described. This technique allows the effects of oxide charge, surface recombination velocity, and bulk traps to be measured independently.

  8. Bipolar single-wall carbon nanotube field-effect transistor

    OpenAIRE

    Babic, Bakir; Iqbal, Mahdi; Schonenberger, Christian

    2002-01-01

    We use a simultaneous flow of ethylene and hydrogen gases to grow single wall carbon nanotubes by chemical vapor deposition. Strong coupling to the gate is inferred from transport measurements for both metallic and semiconducting tubes. At low-temperatures, our samples act as single-electron transistors where the transport mechanism is mainly governed by Coulomb blockade. The measurements reveal very rich quantized energy level spectra spanning from valence to conduction band. The Coulomb dia...

  9. An Evaluation of Bipolar Junction Transistors as Dosimeter for Megavoltage Electron Beams

    Energy Technology Data Exchange (ETDEWEB)

    Passos, Renan Garcia de; Vidal da Silva, Rogerio Matias; Silva, Malana Marcelina Almeida; Souza, Divanizia do Nascimento [Departamento de Fisica, Universidade Federal de Sergipe, Av. Marechal Rondon, sn, Sao Cristovao, SE, 49100-000 (Brazil); Pereira dos Santos, Luiz Antonio [Comissao Nacional de Energia Nuclear, CNEN/CRCN-NE, Av. Prof. Luiz Freire, 1, Recife, PE, 50740-540 (Brazil)

    2015-07-01

    Dosimetry is an extremely important field in medical applications of radiation and nowadays, electron beam is a good option for superficial tumor radiotherapy. Normally, the applied dose to the patient both in diagnostic and therapy must be monitored to prevent injuries and ensure the success of the treatment, therefore, we should always look for improving of the dosimetric methods. Accordingly, the aim of this work is about the use of a bipolar junction transistor (BJT) for electron beam dosimetry. After previous studies, such an electronic device can work as a dosimeter when submitted to ionizing radiation of photon beam. Actually, a typical BJT consists of two PN semiconductor junctions resulting in the NPN structure device, for while, and each semiconductor is named as collector (C), base (B) and emitter (E), respectively. Although the transistor effect, which corresponds to the current amplification, be accurately described by the quantum physics, one can utilize a simple concept from the circuit theory: the base current IB (input signal) is amplified by a factor of β resulting in the collector current IC (output signal) at least one hundred times greater the IB. In fact, the BJT is commonly used as a current amplifier with gain β=I{sub C}/I{sub B}, therefore, it was noticed that this parameter is altered when the device is exposed to ionizing radiation. The current gain alteration can be explained by the trap creation and the positive charges build up, beside the degradation of the lattice structure. Then, variations of the gain of irradiated transistors may justify their use as a dosimeter. Actually, the methodology is based on the measurements of the I{sub C} variations whereas I{sub B} is maintained constant. BC846 BJT type was used for dose monitoring from passive-mode measurements: evaluation of its electrical characteristic before and after irradiation procedure. Thus, IC readings were plotted as a function of the applied dose in 6 MeV electron beam

  10. Understanding the failure mechanisms of microwave bipolar transistors caused by electrostatic discharge

    Science.gov (United States)

    Jin, Liu; Yongguang, Chen; Zhiliang, Tan; Jie, Yang; Xijun, Zhang; Zhenxing, Wang

    2011-10-01

    Electrostatic discharge (ESD) phenomena involve both electrical and thermal effects, and a direct electrostatic discharge to an electronic device is one of the most severe threats to component reliability. Therefore, the electrical and thermal stability of multifinger microwave bipolar transistors (BJTs) under ESD conditions has been investigated theoretically and experimentally. 100 samples have been tested for multiple pulses until a failure occurred. Meanwhile, the distributions of electric field, current density and lattice temperature have also been analyzed by use of the two-dimensional device simulation tool Medici. There is a good agreement between the simulated results and failure analysis. In the case of a thermal couple, the avalanche current distribution in the fingers is in general spatially unstable and results in the formation of current crowding effects and crystal defects. The experimental results indicate that a collector-base junction is more sensitive to ESD than an emitter-base junction based on the special device structure. When the ESD level increased to 1.3 kV, the collector-base junction has been burnt out first. The analysis has also demonstrated that ESD failures occur generally by upsetting the breakdown voltage of the dielectric or overheating of the aluminum-silicon eutectic. In addition, fatigue phenomena are observed during ESD testing, with devices that still function after repeated low-intensity ESDs but whose performances have been severely degraded.

  11. Understanding the failure mechanisms of microwave bipolar transistors caused by electrostatic discharge

    International Nuclear Information System (INIS)

    Liu Jin; Chen Yongguang; Tan Zhiliang; Yang Jie; Zhang Xijun; Wang Zhenxing

    2011-01-01

    Electrostatic discharge (ESD) phenomena involve both electrical and thermal effects, and a direct electrostatic discharge to an electronic device is one of the most severe threats to component reliability. Therefore, the electrical and thermal stability of multifinger microwave bipolar transistors (BJTs) under ESD conditions has been investigated theoretically and experimentally. 100 samples have been tested for multiple pulses until a failure occurred. Meanwhile, the distributions of electric field, current density and lattice temperature have also been analyzed by use of the two-dimensional device simulation tool Medici. There is a good agreement between the simulated results and failure analysis. In the case of a thermal couple, the avalanche current distribution in the fingers is in general spatially unstable and results in the formation of current crowding effects and crystal defects. The experimental results indicate that a collector-base junction is more sensitive to ESD than an emitter-base junction based on the special device structure. When the ESD level increased to 1.3 kV, the collector-base junction has been burnt out first. The analysis has also demonstrated that ESD failures occur generally by upsetting the breakdown voltage of the dielectric or overheating of the aluminum-silicon eutectic. In addition, fatigue phenomena are observed during ESD testing, with devices that still function after repeated low-intensity ESDs but whose performances have been severely degraded. (semiconductor devices)

  12. A novel high breakdown voltage lateral bipolar transistor on SOI with multizone doping and multistep oxide

    International Nuclear Information System (INIS)

    Loan, Sajad A; Qureshi, S; Kumar Iyer, S S

    2009-01-01

    A novel high breakdown voltage lateral bipolar junction transistor (LBJT) on silicon-on- insulator (SOI) is proposed. The novelty of the device is the use of the combination of multistep-doped drift region and multistep buried oxide. The steps in doping and in oxide thickness have been used as a replacement for much complex linearly varying drift doping and linearly varying oxide thickness. The LBJT structure incorporating the combination of multistep doping and multistep oxide is analyzed for electrical characteristics using a two-dimensional numerical simulator MEDICI. Numerical simulation has demonstrated that the breakdown voltage of the proposed device with a two-zone step doped (TZSD) drift region is >150% higher than the conventional device. It has been observed that increasing the number of doping zones to 3 from 2 results in a >40% rise in breakdown voltage. The proposed device gives high breakdown voltage even at high doping concentration in the collector drift region. This reduces the on-resistance of the device and thus improves its speed. The dependence of breakdown voltage on various device parameters has been extensively studied to achieve optimum device performance. A process flow for the device fabrication is also being proposed

  13. Effect of thin emitter set-back layer on GaAs delta-doped emitter bipolar junction transistor

    Science.gov (United States)

    Lew, K. L.; Yoon, S. F.

    2005-05-01

    GaAs delta-doped emitter bipolar junction transistors (δ-BJT) with different emitter set-back layer thicknesses of 10to50nm were fabricated to study the emitter set-back layer thickness effect on device dc performance. We found that the current gain decreases following decrease in the emitter set-back layer thickness. A detailed analysis was performed to explain this phenomenon, which is believed to be caused by reduction of the effective barrier height in the δ-BJT. This is due to change in the electric-field distribution in the delta-doped structure caused by the built-in potential of the base-emitter (B-E ) junction. Considering the recombination and barrier height reduction effects, the thickness of the emitter set-back layer should be designed according to the B-E junction depletion width with a tolerance of ±5nm. The dc performance of a δ-BJT designed based on this criteria is compared to that of a Al0.25Ga0.75As /GaAs heterojunction bipolar transistor (HBT). Both devices employed base doping of 2×1019cm-3 and base-to-emitter doping ratio of 40. Large emitter area (AE≈1.6×10-5cm-2) and small emitter area (AE≈1.35×10-6cm-2) device current gains of 40 and 20, respectively, were obtained in both types of transistors passivated by (NH4)2S treatment. The measured current gain of the GaAs δ-BJT is the highest reported for a homojunction device with such high base-to-emitter doping ratio normally used in HBT devices.

  14. Ionizing radiation effects on conduction and low frequency noise in bipolar transistors

    International Nuclear Information System (INIS)

    Blasquez, G.; Roux-Nogatchewsky, M.

    1980-01-01

    Gate controlled NPN bipolar transistors were irradiated with doses ranging between 10 and 10 4 Gy X rays supplied by a generator functioning at 150 kV. An increase of great amplitude of the base current and of the low frequency noise were observed for both depleted and inverted base surface conditions. It has been shown that these increases were due to the enhancement of the total surface recombination velocity, of the positive charge within the oxide and also of the density of noise traps. Positive correlations were observed between these three surface parameters. These results have been attributed to the ionization of silica by X rays. The transistors partially recovered by means of thermal treatments. It has been suggested that it does not exist specific hardening methods to minimize the noise sensitivity to irradiation [fr

  15. Anomalous dose rate effects in gamma irradiated SiGe heterojunction bipolar transistors

    International Nuclear Information System (INIS)

    Banerjee, G.; Niu, G.; Cressler, J.D.; Clark, S.D.; Palmer, M.J.; Ahlgren, D.C.

    1999-01-01

    Low dose rate (LDR) cobalt-60 (0.1 rad(Si)/s) gamma irradiated Silicon Germanium (SiGe) Heterojunction Bipolar Transistors (HBTs) were studied. Comparisons were made with devices irradiated with 300 rad(Si)/s gamma radiation to verify if LDR radiation is a serious radiation hardness assurance (RHA) issue. Almost no LDR degradation was observed in this technology up to 50 krad(Si). The assumption of the presence of two competing mechanisms is justified by experimental results. At low total dose (le20 krad), an anomalous base current decrease was observed which is attributed to self-annealing of deep-level traps to shallower levels. An increase in base current at larger total doses is attributed to radiation induced generation-recombination (G/R) center generation. Experiments on gate-assisted lateral PNP transistors and 2D numerical simulations using MEDICI were used to confirm these assertions

  16. Tunneling, Current Gain, and Transconductance in Silicon-Germanium Heterojunction Bipolar Transistors Operating at Millikelvin Temperatures

    Science.gov (United States)

    Davidović, D.; Ying, H.; Dark, J.; Wier, B. R.; Ge, L.; Lourenco, N. E.; Omprakash, A. P.; Mourigal, M.; Cressler, J. D.

    2017-08-01

    Quantum-transport measurements in advanced silicon-germanium heterojunction bipolar transistors (SiGe HBTs) are presented and analyzed, including tunneling spectroscopy of discrete impurity levels localized within the transistor and the dependence on an applied magnetic field. The collector current at millikelvin temperatures is well accounted for by ideal electron tunneling throughout the entire base. The amplification principle at millikelvin temperatures is fundamentally quantum mechanical in nature: an increase in base voltage, requiring a moderate base current, creates an equal and opposite decrease in the tunneling barrier seen by the electrons in the emitter, thereby increasing the collector current significantly more than the base current, producing current gain. Highly scaled SiGe HBTs operate predictably at millikelvin temperatures, thus opening the possibility of viable SiGe millikelvin circuitry.

  17. Gamma Irradiation Performance Tests of the Bipolar Junction Transistor (BJT) for Medical Dosimetry Purposes

    Energy Technology Data Exchange (ETDEWEB)

    Nazififard, Mohammad; Suh, Kune Y. [PHILOSOPHIA, Inc., Seoul (Korea, Republic of); Faghihi, Reyhaneh [Kashan Univ. of Medical Science, Kashan (Iran, Islamic Republic of); Norov, Enkhbat [POSTECH, Pohang (Korea, Republic of)

    2014-05-15

    Two basic radiation damage mechanisms may affect semiconductor devices which are Displacement damage and Ionization damage. In displacement damage mechanism, the incident radiation displaces silicon atoms from their lattice sites. The resulting defects alter the electronic characteristics of the crystal. In ionization damage mechanism, the absorbed energy by electronic ionization in insulating layers liberates charge carriers, which diffuse or drift to other locations where they are trapped, leading to unintended concentrations of charge and, as a consequence, parasitic fields. Both mechanisms are important in detectors, transistors and integrated circuits. Hardly a system is immune to either one phenomenon and most are sensitive to both. This paper investigates the behavior of Bipolar Junction Transistors (BJTs), exposed to radiation in order to establish their applicability in a radiation environment.

  18. Electrical determination of the bandgap energies of the emitter and base regions of bipolar junction transistors

    Science.gov (United States)

    Mimila-Arroyo, J.

    2016-10-01

    A pure electrical method is presented to extract emitter and base bandgaps of a bipolar junction transistor (BJT) at the locations where the minority carrier injection takes place. It is based on the simultaneous measurement of the collector and base currents as a function of the emitter-base forward bias (Gummer plot) and the corresponding current gain. From the obtained saturation currents as a function of temperature, we extract the bandgap energies. The accuracy of the method is demonstrated for InGaP-GaAs, Si, and Ge commercial devices. For InGaP-GaAs transistors, the results can be understood if the emitter-base heterojunction is not an abrupt but a gradual one. The presented method is a reliable tool that can aid in the development of new compound semiconductor based BJTs whose bandgap energies are highly sensitive to their composition.

  19. Origin of 1/f PM and AM noise in bipolar junction transistor amplifiers.

    Science.gov (United States)

    Walls, F L; Ferre-Pikal, E S; Jefferts, S R

    1997-01-01

    In this paper we report the results of extensive research on phase modulation (PM) and amplitude modulation (AM) noise in linear bipolar junction transistor (BJT) amplifiers. BJT amplifiers exhibit 1/f PM and AM noise about a carrier signal that is much larger than the amplifiers thermal noise at those frequencies in the absence of the carrier signal. Our work shows that the 1/f PM noise of a BJT based amplifier is accompanied by 1/f AM noise which can be higher, lower, or nearly equal, depending on the circuit implementation. The 1/f AM and PM noise in BJTs is primarily the result of 1/f fluctuations in transistor current, transistor capacitance, circuit supply voltages, circuit impedances, and circuit configuration. We discuss the theory and present experimental data in reference to common emitter amplifiers, but the analysis can be applied to other configurations as well. This study provides the functional dependence of 1/f AM and PM noise on transistor parameters, circuit parameters, and signal frequency, thereby laying the groundwork for a comprehensive theory of 1/f AM and PM noise in BJT amplifiers. We show that in many cases the 1/f PM and AM noise can be reduced below the thermal noise of the amplifier.

  20. Ultra-High Voltage 4H-SiC Bi-Directional Insulated Gate Bipolar Transistors

    Science.gov (United States)

    Chowdhury, Sauvik

    4H- Silicon Carbide (4H-SiC) is an attractive material for power semiconductor devices due to its large bandgap, high critical electric field and high thermal conductivity compared to Silicon (Si). For ultra-high voltage applications (BV > 10 kV), 4H-SiC Insulated Gate Bipolar Transistors (IGBTs) are favored over unipolar transistors due to lower conduction losses. With improvements in SiC materials and processing technology, promising results have been demonstrated in the area of conventional unidirectional 4H-SiC IGBTs, with breakdown voltage ratings up to 27 kV. This research presents the experimental demonstration of the world's first high voltage bi-directional power transistors in 4H-SiC. Traditionally, four (two IGBTs and two diodes) or two (two reverse blocking IGBTs) semiconductor devices are necessary to yield a bidirectional switch. With a monolithically integrated bidirectional switch as presented here, the number of semiconductor devices is reduced to only one, which results in increased reliability and reduced cost of the overall system. Additionally, by using the unique dual gate operation of BD-IGBTs, switching losses can be reduced to a small fraction of that in conventional IGBTs, resulting in increased efficiency. First, the performance limits of SiC IGBTs are calculated by using analytical methods. The performance benefits of SiC IGBTs over SiC unipolar devices and Si IGBTs are quantified. Numerical simulations are used to optimize the unit cell and edge termination structures for a 15 kV SiC BD-IGBT. The effect of different device parameters on BD-IGBT static and switching performance are quantified. Second, the process technology necessary for the fabrication of high voltage SiC BD-IGBTs is optimized. The effect of different process steps on parameters such as breakdown voltage, carrier lifetime, gate oxide reliability, SiO2-SiC interface charge density is quantified. A carrier lifetime enhancement process has been optimized for lightly doped

  1. Improved Model for Increased Surface Recombination Current in Irradiated Bipolar Junction Transistors

    Science.gov (United States)

    Barnaby, H. J.; Vermeire, B.; Campola, M. J.

    2015-08-01

    Current gain degradation in irradiated bipolar junction transistors is primarily due to excess base current caused by enhanced carrier recombination in the emitter-base space-charge region (SCR). Radiation-induced traps at the interface between silicon and the bipolar base oxide facilitate the recombination process primarily above the sensitive emitter-base junction. This leads to an increase in surface recombination current in the SCR, which is a non-ideal component of the BJT's base current characteristic under active bias conditions. In this paper, we derive a precise analytical model for surface recombination current that captures bias dependencies typically omitted from traditional models. This improved model is validated by comparisons to these traditional approaches.

  2. Evaluation of Enhanced Low Dose Rate Sensitivity in Discrete Bipolar Junction Transistors

    Science.gov (United States)

    Chen, Dakai; Ladbury Raymond; LaBel, Kenneth; Topper, Alyson; Ladbury, Raymond; Triggs, Brian; Kazmakites, Tony

    2012-01-01

    We evaluate the low dose rate sensitivity in several families of discrete bipolar transistors across device parameter, quality assurance level, and irradiation bias configuration. The 2N2222 showed the most significant low dose rate sensitivity, with low dose rate enhancement factor of 3.91 after 100 krad(Si). The 2N2907 also showed critical degradation levels. The devices irradiated at 10 mrad(Si)/s exceeded specifications after 40 and 50 krad(Si) for the 2N2222 and 2N2907 devices, respectively.

  3. Development of 8-inch Key Processes for Insulated-Gate Bipolar Transistor

    Directory of Open Access Journals (Sweden)

    Guoyou Liu

    2015-09-01

    Full Text Available Based on the construction of the 8-inch fabrication line, advanced process technology of 8-inch wafer, as well as the fourth-generation high-voltage double-diffused metal-oxide semiconductor (DMOS+ insulated-gate bipolar transistor (IGBT technology and the fifth-generation trench gate IGBT technology, have been developed, realizing a great-leap forward technological development for the manufacturing of high-voltage IGBT from 6-inch to 8-inch. The 1600 A/1.7 kV and 1500 A/3.3 kV IGBT modules have been successfully fabricated, qualified, and applied in rail transportation traction system.

  4. Terahertz emission from collapsing field domains during switching of a gallium arsenide bipolar transistor.

    Science.gov (United States)

    Vainshtein, Sergey; Kostamovaara, Juha; Yuferev, Valentin; Knap, Wojciech; Fatimy, Abdel; Diakonova, Nina

    2007-10-26

    Broadband pulsed THz emission with peak power in the sub-mW range has been observed experimentally during avalanche switching in a gallium arsenide bipolar junction transistor at room temperature, while significantly higher total generated power is predicted in simulations. The emission is attributed to very fast oscillations in the conductivity current across the switching channels, which appear as a result of temporal evolution of the field domains generated in highly dense electron-hole plasma. This plasma is formed in turn by powerful impact ionization in multiple field domains of ultrahigh amplitude.

  5. Bias dependence of synergistic radiation effects induced by electrons and protons on silicon bipolar junction transistors

    Science.gov (United States)

    Liu, Chaoming; Li, Xingji; Yang, Jianqun; Ma, Guoliang; Xiao, Liyi

    2015-06-01

    Bias dependence on synergistic radiation effects caused by 110 keV electrons and 170 keV protons on the current gain of 3DG130 NPN bipolar junction transistors (BJTs) is studied in this paper. Experimental results indicate that the influence induced by 170 keV protons is always enhancement effect during the sequential irradiation. However, the influence induced by 110 keV electrons on the BJT under various bias cases is different during the sequential irradiation. The transition fluence of 110 keV electrons is dependent on the bias case on the emitter-base junction of BJT.

  6. Separation of ionization and displacement damage using gate-controlled lateral PNP bipolar transistors

    Science.gov (United States)

    Ball, D. R.; Schrimpf, R. D.; Barnaby, H. J.

    2002-12-01

    Proton irradiation produces both ionization and displacement damage in semiconductor devices. In this paper, a technique for separating the effects of these two types of damage using a lateral PNP bipolar transistor with a gate contact over the active base region is described. By biasing the gate appropriately, the effects of ionization-induced damage are minimized and the effects of displacement damage can be measured independently. Experiments and simulations are used to validate this approach and provide insight into proton-induced BJT degradation.

  7. Bipolar redox behaviour, field-effect mobility and transistor switching of the low-molecular azo glass AZOPD.

    Science.gov (United States)

    Arlt, Michael; Scheffler, Ayna; Suske, Irina; Eschner, Michael; Saragi, Tobat P I; Salbeck, Josef; Fuhrmann-Lieker, Thomas

    2010-11-07

    We present electrochemical and spectroelectrochemical data for the bipolar azo compound N,N'-diphenyl-N,N'-bis[4-(phenylazo)phenyl]-4,4'diaminobiphenyl (AZOPD) demonstrating reversible bipolar redox behaviour with a bandgap of 2.1 eV. The reduced species formed upon two-electron transfer can be described as bis(radical anion) as was confirmed by comparison with a reference compound with only one azo chromophore. Hole and electron transport behaviour in amorphous films was demonstrated by the fabrication of organic field-effect transistors using gold and magnesium contacts, respectively. The transistors are sensitive to light due to E-Z photoisomerization.

  8. Fabrication and high temperature characteristics of ion-implanted GaAs bipolar transistors and ring-oscillators

    Science.gov (United States)

    Doerbeck, F. H.; Yuan, H. T.; Mclevige, W. V.

    1981-01-01

    Ion implantation techniques that permit the reproducible fabrication of bipolar GaAs integrated circuits are studied. A 15 stage ring oscillator and discrete transistor were characterized between 25 and 400 C. The current gain of the transistor was found to increase slightly with temperature. The diode leakage currents increase with an activation energy of approximately 1 eV and dominate the transistor leakage current 1 sub CEO above 200 C. Present devices fail catastrophically at about 400 C because of Au-metallization.

  9. The Aluminum-Free P-n-P InGaAsN Double Heterojunction Bipolar Transistors

    Energy Technology Data Exchange (ETDEWEB)

    CHANG,PING-CHIH; LI,N.Y.; BACA,ALBERT G.; MONIER,C.; LAROCHE,J.R.; HOU,H.Q.; REN,F.; PEARTON,S.J.

    2000-08-01

    The authors have demonstrated an aluminum-free P-n-P GaAs/InGaAsN/GaAs double heterojunction bipolar transistor (DHBT). The device has a low turn-on voltage (V{sub ON}) that is 0.27 V lower than in a comparable P-n-p AlGaAs/GaAs HBT. The device shows near-ideal D. C. characteristics with a current gain ({beta}) greater than 45. The high-speed performance of the device are comparable to a similar P-n-p AlGaAs/GaAs HBT, with f{sub T} and f{sub MAX} values of 12 GHz and 10 GHz, respectively. This device is very suitable for low-power complementary HBT circuit applications, while the aluminum-free emitter structure eliminates issues typically associated with AlGaAs.

  10. Influence of the external component on the damage of the bipolar transistor induced by the electromagnetic pulse

    Energy Technology Data Exchange (ETDEWEB)

    Xi Xiaowen; Chai Changchun; Ren Xingrong; Yang Yintang; Ma Zhenyang; Wang Jing, E-mail: xixiaowen523103@163.co [Key Laboratory of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi' an 710071 (China)

    2010-07-15

    A study on the influence of the external resistor and the external voltage source during the injection of the electromagnetic pulse (EMP) into the bipolar transistor (BJT) is carried out. Research shows that the increase of the external resistor R{sub b} at base makes the burnout time of the device decrease slightly, the increase of the external voltage source V{sub be} at base can aid the damage of the device when the magnitude of the injecting voltage is relatively low and has little influence when the magnitude is sufficiently high causing the device appearing the PIN structure damage, and the increase of the external resistor R{sub e} can remarkably reduce the voltage drops added to the device and improve the durability of the device. In the final analysis, the effect of the external circuit component on the BJT damage is the influence on the condition which makes the device appear current-mode second breakdown.

  11. Influence of the external component on the damage of the bipolar transistor induced by the electromagnetic pulse

    Science.gov (United States)

    Xiaowen, Xi; Changchun, Chai; Xingrong, Ren; Yintang, Yang; Zhenyang, Ma; Jing, Wang

    2010-07-01

    A study on the influence of the external resistor and the external voltage source during the injection of the electromagnetic pulse (EMP) into the bipolar transistor (BJT) is carried out. Research shows that the increase of the external resistor Rb at base makes the burnout time of the device decrease slightly, the increase of the external voltage source Vbe at base can aid the damage of the device when the magnitude of the injecting voltage is relatively low and has little influence when the magnitude is sufficiently high causing the device appearing the PIN structure damage, and the increase of the external resistor Re can remarkably reduce the voltage drops added to the device and improve the durability of the device. In the final analysis, the effect of the external circuit component on the BJT damage is the influence on the condition which makes the device appear current-mode second breakdown.

  12. Urea biosensor based on an extended-base bipolar junction transistor.

    Science.gov (United States)

    Sun, Tai-Ping; Shieh, Hsiu-Li; Liu, Chun-Lin; Chen, Chung-Yuan

    2014-01-01

    In this study, a urea biosensor was prepared by the immobilization of urease onto the sensitive membrane of an extended-base bipolar junction transistor. The pH variation was used to detect the concentration of urea. The SnO2/ITO glass, fabricated by sputtering SnO2 on the conductive ITO glass, was used as a pH-sensitive membrane, which was connected with a commercial bipolar junction transistor device. The gels, fabricated by the poly vinyl alcohol with pendent styrylpyridinium groups, were used to immobilize the urease. This readout circuit, fabricated in a 0.35-um CMOS 2P4M process, operated at 3.3V supply voltage. This circuit occupied an area of 1.0 mm × 0.9 mm. The dynamic range of the urea biosensor was from 1.4 to 64 mg/dl at the 10 mM phosphate buffer solution and the sensitivity of this range was about 65.8 mV/pUrea. The effect of urea biosensors with different pH values was considered, and the characteristics of urea biosensors based on EBBJT were described.

  13. Trivalued Memory Circuit Using Metal-Oxide-Semiconductor Field-Effect Transistor Bipolar-Junction-Transistor Negative-Differential-Resistance Circuits Fabricated by Standard SiGe Process

    Science.gov (United States)

    Gan, Kwang-Jow; Tsai, Cher-Shiung; Liang, Dong-Shong; Wen, Chun-Ming; Chen, Yaw-Hwang

    2006-09-01

    A trivalued memory circuit based on two cascoded metal-oxide-semiconductor field-effect transistor bipolar-junction-transistor negative-differential-resistance (MOS-BJT-NDR) devices is investigated. The MOS-BJT-NDR device is made of MOS and BJT devices, but it can show the NDR current-voltage characteristic by suitably arranging the MOS parameters. We demonstrate a trivalued memory circuit using the two-peak MOS-BJT-NDR circuit as the driver and a resistor as the load. The MOS-BJT-NDR devices and memory circuits are fabricated by the standard 0.35 μm SiGe process.

  14. Technique for electronic measurement of semi-reduction layer using bipolar transistor of junction; Tecnica de medicao eletronica da camada semiredutora utilizando transistor bipolar de juncao

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Luiz A.P.; Barros, Fabio R.; Santos, Marcus A.P., E-mail: lasantos@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Monte, David S.; Santos, Jose A.P., E-mail: dsmonte@scients.com.br [SCIENTS, Recife, PE (Brazil)

    2014-07-01

    Recommendations of the International Commission on Radiological Protection (ICRP), the World Health Organization (WHO) and also of the International Atomic Energy Agency (IAEA) suggest equipment for X-rays diagnosis are checked for conformance to their parameters, such as Layer Semi-Reduction (CSR). The importance of verification of diagnostic radiology in parameters is because of have records that forces patients undergoing radiation doses in some clinics, up to 300% the reference values suggested by international agencies which doses are considered unnecessary, and even harmful, either because of physical or variable greatness of being out of control nominal specification, or the fact of having to repeat the radiographs. In this context, the purpose of this study was an innovative methodology that is the use of bipolar transistor junction (TBJ) to measure the aluminum CSR in diagnostic X-ray equipment beams. Although the TBJ be a device invented in the last century, only in recent years have explored their potential as X-ray sensor applied to diagnosis. The study indicates that the tested device can operating the detection of X-rays is properly polarized with electrical signals that can detect interference of the interaction of X-ray photons with the PN junction formed by the base and emitter terminals. The result of the developed technique was compared to CSR measurements obtained with detection systems standards and it was found that the BJT provides values for aluminum CSR relative errors less than 5%.

  15. Study of an Insulated Gate Bipolar Transistor (IGBT) and its connection in series. Application at a chopper 1500V-5A-10kHz

    International Nuclear Information System (INIS)

    Gros, P.

    1993-01-01

    In the frame of the tokamak ITER (International Thermonuclear Experimental Reactor) we have studied, for neutral particle injection, a converter with at least two static interrupters by Mosfet transistor, bipolar transistor or Insulated Gate Bipolar Transistor (IGBT). After a comparison between these three types of transistors, by the simulating software MICROCAP, a serial of tests has shown the advantages of the IGBT. A command, associated with two IGBT of equivalent characteristics, has given a simple and efficacious solution. The performances are: (1) between two blockages: 50 ns without overvoltage, (2) between two cut-off: 60 ns. 40 figs; 30 refs; 10 annexes

  16. Design of the optimum insulator gate bipolar transistor using response surface method with cluster analysis

    CERN Document Server

    Wang, Chi Ling; Huang Sy Ruen; Yeh Chao Yu

    2004-01-01

    In this paper, a statistical methodology that can be used for the optimization of the Insulator Gate Bipolar Transistor (IGBT) devices is proposed. This is achieved by integrating the response surface method (RSM) with cluster analysis, weighted composite method and genetic algorithm (GA). The device characteristic of IGBT was simulated based upon the fabrication simulator, ATHENA, and the device simulator, ATLAS. This methodology, yielded another way to investigate the IGBT device and to make a decision in the tradeoff between the breakdown voltage and the on-resistance. In this methodology, we also show how to use cluster analysis to determine the dominant factors that are not visible in the screening of all experiments. 20 Refs.

  17. Contribution to the study of fluctuations in transistors (bipolar and junction field effect types)

    International Nuclear Information System (INIS)

    Borel, J.

    1970-01-01

    A brief review of the basic theory of fluctuations in semiconductors is given: shot, thermal low frequency noise. A measuring set has been built to draw noise spectrums (current or voltage). Noise parameters of bipolar transistors are given, mainly noise voltage. Noise current, noise factor and correlation between noise sources are also calculated. Measurements of noise parameters fit well with theory for various devices made in different technologies: alloyed, mesa, planar. Then we give results of the calculation of noise parameters in a FET starting from a simplified model of the device. Low frequency noise is taken into account. Measurements of the parameters and of the spectrum agree fairly well with the theory. Studies of low frequency noise versus temperature give the density and energy of traps located in the space charge layers and an idea of the impurity encountered in these space charge layers [fr

  18. Microwave characterization and modeling of GaAs/AlGaAs heterojunction bipolar transistors

    Science.gov (United States)

    Simons, Rainee N.; Romanofsky, Robert R.

    1987-01-01

    The characterization and modeling of a microwave GaAs/AlGaAs heterojunction Bipolar Transistor (HBT) are discussed. The de-embedded scattering parameters are used to derive a small signal lumped element equivalent circuit model using EEsof's Touchstone software package. Each element in the equivalent circuit model is shown to have its origin within the device. The model shows good agreement between the measured and modeled scattering parameters over a wide range of bias currents. Further, the MAG (maximum available power gain) and the h sub 21 (current gain) calculated from the measured data and those predicted by the model are also in good agreement. Consequently, the model should also be capable of predicting the f sub max and the f sub T of other HBTs.

  19. Analysis of long-term ionizing radiation effects in bipolar transistors

    Science.gov (United States)

    Stanley, A. G.; Martin, K. E.

    1978-01-01

    The ionizing radiation effects of electrons on bipolar transistors have been analyzed using the data base from the Voyager project. The data were subjected to statistical analysis, leading to a quantitative characterization of the product and to data on confidence limits which will be useful for circuit design purposes. These newly-developed methods may form the basis for a radiation hardness assurance system. In addition, an attempt was made to identify the causes of the large variations in the sensitivity observed on different product lines. This included a limited construction analysis and a determination of significant design and processes variables, as well as suggested remedies for improving the tolerance of the devices to radiation.

  20. Characterization of insulated-gate bipolar transistor temperature on insulating, heat-spreading polycrystalline diamond substrate

    Science.gov (United States)

    Umezawa, Hitoshi; Shikata, Shin-ichi; Kato, Yukako; Mokuno, Yoshiaki; Seki, Akinori; Suzuki, Hiroshi; Bessho, Takeshi

    2017-01-01

    Polycrystalline diamond films have been utilized as direct bonding aluminum (DBA) substrates to improve cooling efficiency. A diamond film with a high quality factor was characterized by Raman spectroscopy and showed a high thermal conductivity of more than 1800 W m-1 K-1 and a low leakage current, even at an applied bias of 3 kV, because of the suppression of electrical conduction through the grain boundaries. The operating temperatures of Insulated-gate bipolar transistors (IGBTs) on diamond DBAs were 20-28% lower than those on AlN DBAs. The thermal resistivity of the diamond DBA module was 0.32 °C/W. The uniformity of the temperature distribution on a diamond DBA was excellent.

  1. Analysis of the dynamic avalanche of punch through insulated gate bipolar transistor (PT-IGBT)

    Science.gov (United States)

    Lefranc, P.; Planson, D.; Morel, H.; Bergogne, D.

    2009-09-01

    In the paper proposed here, we are studying the dynamic avalanche from experimental results first, dynamic avalanche is identified on a punch through insulated gate bipolar transistor (PT-IGBT) module 1200 V-300 A from Mitsubishi. Secondly, the phenomenon is analysed thanks to simple solid state devices equations. Numerical simulations are used to confirm experimental results. Simulation results allows us locating the active area of the dynamic avalanche during turn-off under over-current conditions. A PT-IGBT cell is described with MEDICI™, a finite element simulator. A mixed-mode simulation is performed thanks to MEDICI™ and SPICE™. The circuit simulated here is a buck topology with an inductive load. Finally, a thermal analysis is performed to estimate temperature increase due to dynamic avalanche.

  2. A New Switching Impulse Generator Based on Transformer Boosting and Insulated Gate Bipolar Transistor Trigger Control

    Directory of Open Access Journals (Sweden)

    Ming Ren

    2016-08-01

    Full Text Available To make the switching impulse (SI generator more compact, portable and feasible in field tests, a new approach based on transformer boosting was developed. To address problems such as triggering synchronization and electromagnetic interference involved with the traditional spark gap, an insulated gate bipolar transistor (IGBT module with drive circuit was employed as the impulse trigger. An optimization design for the component parameters of the primary winding side of the transformer was realized by numerical calculation and error correction. Experiment showed that the waveform parameters of SI and oscillating switching impulse (OSI voltages generated by the new generator were consistent with the numerical calculation and the error correction. The generator was finally built on a removable high voltage transformer with small size. Thus the volume of the generator is significantly reduced. Experiments showed that the waveform parameters of SI and OSI voltages generated by the new generator were basically consistent with the numerical calculation and the error correction.

  3. Effect of the interface recombination current fluctuations on 1/f noise of gated lateral bipolar transistors

    Science.gov (United States)

    Romas, Gregory G., Jr.; Ul Hoque, Md Mazhar; Celik-Butler, Zeynep

    2003-05-01

    A gated lateral bipolar transistor is a bulk lateral BJT in parallel with a MOSFET at the surface. The base current components such as surface recombination and space charge recombination currents are two of the dominant noise sources in the lateral BJT. If the gate is biased such that the MOSFET is in the off-state by accumulating carriers underneath the oxide in the base surface, the noise contribution by these two base current (Ib) components can be better understood. The carrier accumulation in the base surface can be modulated with different gate bias, which in turn will affect the fluctuation of the surface recombination current component. In this paper, noise power spectral density of gated lateral PNP transistors, fabricated in Texas Instruments Standard Bipolar Process, has been discussed. The base current noise power spectral density (SIb) was extracted from the cross-correlation noise spectrum measured between the base and the collector circuits for different gate biasing conditions. Based on the frequency exponent dependence of the noise power spectral density, it was found that the noise in the low frequency range is in the form of 1/f noise. SIb was found to be the dominant noise source for these devices as the coherence between the base and collector power spectral density was very close to 1. SIb was extracted for a base current range of 8 nA to 1microA for a gate bias range of 0V to 40V. The SPICE noise model parameters, AF and KF were also determined for each case from the dependence of SIb on Ib. The noise was measured on devices with different base width values.

  4. Design method for a digitally trimmable MOS transistor structure

    DEFF Research Database (Denmark)

    Ning, Feng; Bruun, Erik

    1996-01-01

    A digitally trimmable MOS transistor is a MOS transistor consisting of a drain, a source, and a main gate as well as several subgates. The transconductance of the transistor is tunabledigitally by means of connecting subgates either to the main gate or to the source terminal. In this paper......, a systematic design method for a digitally trimmable MOS transistor structure is proposed. Using the proposed method, we have designed a digitally trimmable MOS transistor structure and prototype devices were fabricated in a 2.4 micron n-well CMOS technology. Through measurements on these devices, the design...... method has been experimentally confirmed. The trimmable MOS transistor structure has been applied to a high precision current mirror to reduce mismatch in the current mirror. With the trimmable transistor structure, the mismatch can be reduced by more than one order of magnitude....

  5. The effect of fluorine in low thermal budget polysilicon emitters for SiGe heterojunction bipolar transistors

    International Nuclear Information System (INIS)

    Schiz, F.J.W.

    1999-03-01

    This thesis investigates the behaviour of fluorine in two types of polysilicon emitter. In the first type the emitter is deposited at 610 deg. C as polycrystalline silicon (p-Si). In the second type the emitter is deposited at 560 deg. C as amorphous silicon (α-Si). The amorphous silicon 1 then regrows to polysilicon during subsequent high temperature anneals. Remarkably different behaviour of fluorine is seen in as-deposited α-Si and as-deposited p-Si emitter bipolar transistors. In the most extreme case, fluorine-implanted as-deposited p-Si devices show a base current increase by a factor of 1.5 and equivalent α-Si devices a base current decrease by a factor of 10.0 compared to unimplanted devices. Cross-section TEM observations are made to study the structure of the polysilicon/silicon interface and SIMS measurements to study the distribution of the fluorine in the polysilicon. The TEM results correlate well with the electrical results and show that fluorine accelerates interfacial oxide breakup. Furthermore, they show that for a given thermal budget, more interfacial oxide breakup and thus more epitaxial regrowth is obtained for transistors with p-Si polysilicon emitters. This results in a lower emitter resistance, for example as low as 12Ωμm 2 for as-deposited p-Si devices. The base current suppression for as-deposited α-Si devices is explained by fluorine passivation of trapping states at the interface. Analysis of the fluorine SIMS profiles suggests that they do not resemble normal diffusion profiles, but are due to fluorine trapped at defects. It is shown that a reciprocal relationship exists between the fluorine dose in the bulk polysilicon layer and the fluorine dose at the interface. In as-deposited α-Si devices, there is more fluorine trapped at defects in the bulk polysilicon layer, so less is available to diffuse to the interface. As a result there is less interfacial oxide breakup and more passivation in the as-deposited α-Si devices. These

  6. Paired structures and bipolar knowledge representation

    DEFF Research Database (Denmark)

    Montero, Javier; Bustince, Humberto; Franco, Camilo

    In this strictly positional paper we propose a general approach to bipolar knowledge representation, where the meaning of concepts can be modelled by examining their decomposition into opposite and neutral categories. In particular, it is the semantic relationship between the opposite categories...... which suggests the emergence of a paired structure and its associated type of neutrality, being there three general types of neutral categories, namely indeterminacy, ambivalence and conflict. Hence, the key issue consists in identifying the semantic opposition characterizing the meaning of concepts...... and at the same time the type of neutrality rising in between opposites. Based on this first level of bipolar knowledge representation, paired structures in fact offer the means to characterize a specific bipolar valuation scale depending on the meaning of the concept that has to be verified. In this sense...

  7. Incident particle range dependence of radiation damage in a power bipolar junction transistor

    Science.gov (United States)

    Liu, Chao-Ming; Li, Xing-Ji; Geng, Hong-Bin; Rui, Er-Ming; Guo, Li-Xin; Yang, Jian-Qun

    2012-10-01

    The characteristic degradations in silicon NPN bipolar junction transistors (BJTs) of type 3DD155 are examined under the irradiations of 25-MeV carbon (C), 40-MeV silicon (Si), and 40-MeV chlorine (Cl) ions respectively. Different electrical parameters are measured in-situ during the exposure of heavy ions. The experimental data shows that the changes in the reciprocal of the gain variation (Δ(1/β)) of 3DD155 transistors irradiated respectively by 25-MeV C, 40-MeV Si, and 40-MeV Cl ions each present a nonlinear behaviour at a low fluence and a linear response at a high fluence. The Δ(1/β) of 3DD155 BJT irradiated by 25-MeV C ions is greatest at a given fluence, a little smaller when the device is irradiated by 40-MeV Si ions, and smallest in the case of the 40-MeV Cl ions irradiation. The measured and calculated results clearly show that the range of heavy ions in the base region of BJT affects the level of radiation damage.

  8. Annealing effects and DLTS study on NPN silicon bipolar junction transistors irradiated by heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chaoming; Li, Xingji, E-mail: lxj0218@hit.edu.cn; Yang, Jianqun; Rui, Erming

    2014-01-21

    Isochronal anneal sequences have been carried out on 3DG112 silicon NPN bipolar junction transistors (BJTs) irradiated with 20 MeV bromine (Br) heavy ions. The Gummel curve is utilized to characterize the annealing behavior of defects in both the emitter-base depletion region and the neutral base. We find that the base current (I{sub B}) decreases with the increasing annealing temperature, while the collector current (I{sub C}) remains invariable. The current gain varies slightly, when the annealing temperature (T{sub A}) is lower than 400 K, while varies rapidly at T{sub A}<450 K, and the current gain of the 3DG112 BJT annealing at 700 K almost restore to that of the pre-radiation transistor. Deep level transient spectroscopy (DLTS) data is used to assign the relative magnitude of each of the important defects. Based on the in situ electrical measurement and DLTS spectra, it is clear that the V{sub 2}(−/0)+V-P traps are the main contribution to the degradation of current gain after the 20 MeV Br ions irradiation. The V{sub 2}(−/0)+V-P peak has many of the characteristics expected for the current gain degradation.

  9. Annealing effects and DLTS study on NPN silicon bipolar junction transistors irradiated by heavy ions

    Science.gov (United States)

    Liu, Chaoming; Li, Xingji; Yang, Jianqun; Rui, Erming

    2014-01-01

    Isochronal anneal sequences have been carried out on 3DG112 silicon NPN bipolar junction transistors (BJTs) irradiated with 20 MeV bromine (Br) heavy ions. The Gummel curve is utilized to characterize the annealing behavior of defects in both the emitter-base depletion region and the neutral base. We find that the base current (IB) decreases with the increasing annealing temperature, while the collector current (IC) remains invariable. The current gain varies slightly, when the annealing temperature (TA) is lower than 400 K, while varies rapidly at TABJT annealing at 700 K almost restore to that of the pre-radiation transistor. Deep level transient spectroscopy (DLTS) data is used to assign the relative magnitude of each of the important defects. Based on the in situ electrical measurement and DLTS spectra, it is clear that the V2(-/0)+V-P traps are the main contribution to the degradation of current gain after the 20 MeV Br ions irradiation. The V2(-/0)+V-P peak has many of the characteristics expected for the current gain degradation.

  10. Base profile design for high-performance operation of bipolar transistors at liquid-nitrogen temperature

    International Nuclear Information System (INIS)

    Stork, J.M.C.; Harame, D.L.; Meyerson, B.S.; Nguyen, T.N.

    1989-01-01

    The base profile requirements of Si bipolar junction transistors (BJT's) high-performance operation at liquid-nitrogen temperature are examined. Measurements of thin epitaxial-base polysilicon-emitter n-p-n transistors with increasing base doping show the effects of bandgap narrowing, mobility changes, and carrier freezeout. At room temperature the collector current at low injection is proportional to the integrated base charge, independent of the impurity distribution. At temperatures below 150 Κ, however, minority injection is dominated by the peak base doping because of the greater effectiveness of bandgap narrowing. When the peak doping in the base approaches 10 19 cm -3 , the bandgap difference between emitter and base is sufficiently small that the current gain no longer monotonically decreases with lower temperature but instead shows a maximum as low as 180 Κ. The device design window appears limited at the low-current end by increased base-emitter leakage due to tunneling and by resistance control at the high-current end. Using the measured dc characteristics, circuit delay calculations are made to estimate the performance of an ECL ring oscillator at room and liquid-nitrogen temperatures. It is shown that if the base doping can be raised to 10 19 cm -3 while keeping the base thickness constant, the minimum delay at liquid nitrogen can approach the delay of optimized devices at room temperature

  11. Application of Bipolar Fuzzy Sets in Graph Structures

    Directory of Open Access Journals (Sweden)

    Muhammad Akram

    2016-01-01

    Full Text Available A graph structure is a useful tool in solving the combinatorial problems in different areas of computer science and computational intelligence systems. In this paper, we apply the concept of bipolar fuzzy sets to graph structures. We introduce certain notions, including bipolar fuzzy graph structure (BFGS, strong bipolar fuzzy graph structure, bipolar fuzzy Ni-cycle, bipolar fuzzy Ni-tree, bipolar fuzzy Ni-cut vertex, and bipolar fuzzy Ni-bridge, and illustrate these notions by several examples. We study ϕ-complement, self-complement, strong self-complement, and totally strong self-complement in bipolar fuzzy graph structures, and we investigate some of their interesting properties.

  12. Contact Metallization and Packaging Technology Development for SiC Bipolar Junction Transistors, PiN Diodes, and Schottky Diodes Designed for Long-Term Operations at 350degreeC

    Science.gov (United States)

    2006-05-01

    for high temperature contacts. A Bipolar Junction Transistor ( BJT ) in 4H-SiC can operate at higher temperatures (300oC) because its operation does not...AFRL-PR-WP-TR-2006-2181 CONTACT METALLIZATION AND PACKAGING TECHNOLOGY DEVELOPMENT FOR SiC BIPOLAR JUNCTION TRANSISTORS , PiN DIODES, AND...SUBTITLE CONTACT METALLIZATION AND PACKAGING TECHNOLOGY DEVELOPMENT FOR SiC BIPOLAR JUNCTION TRANSISTORS , PiN DIODES, AND SCHOTTKY DIODES DESIGNED

  13. Silicon-on-Insulator Lateral-Insulated-Gate-Bipolar-Transistor with Built-in Self-anti-ESD Diode

    Directory of Open Access Journals (Sweden)

    Xiaojun Cheng

    2014-05-01

    Full Text Available Power SOI (Silicon-On-Insulator devices have an inherent sandwich structure of MOS (Metal-Oxide-Semiconductor gate which is very easy to suffer ESD (Electro-Static Discharge overstress. To solve this reliability problem, studies on design and modification of a built-in self-anti-ESD diode for a preliminarily optimized high voltage SOI LIGBT (Lateral-Insulated-Gate-Bipolar-Transistor were carried out on the Silvaco TCAD (Technology-Computer-Aided-Design platform. According to the constrains of the technological process, the new introduction of the N+ doped region into P-well region that form the built-in self-anti-ESD diode should be done together with the doping of source under the same mask. The modifications were done by adjusting the vertical impurity profile in P-well into retrograde distribution and designing a cathode plate with a proper length to cover the forward depletion terminal and make sure that the thickness of the cathode plate is the same as that of the gate plate. The simulation results indicate that the modified device structure is compatible with the original one in process and design, the breakdown voltage margin of the former was expanded properly, and both the transient cathode voltages are clamped low enough very quickly. Therefore, the design and optimization results of the modified device structure of the built-in self-anti-ESD diode for the given SOI LIGBT meet the given requirements.

  14. A 65-kV insulated gate bipolar transistor switch applied in damped AC voltages partial discharge detection system.

    Science.gov (United States)

    Jiang, J; Ma, G M; Luo, D P; Li, C R; Li, Q M; Wang, W

    2014-02-01

    Damped AC voltages detection system (DAC) is a productive way to detect the faults in power cables. To solve the problems of large volume, complicated structure and electromagnetic interference in existing switches, this paper developed a compact solid state switch based on electromagnetic trigger, which is suitable for DAC test system. Synchronous electromagnetic trigger of 32 Insulated Gate Bipolar Transistors (IGBTs) in series was realized by the topological structure of single line based on pulse width modulation control technology. In this way, external extension was easily achieved. Electromagnetic trigger and resistor-capacitor-diode snubber circuit were optimized to reduce the switch turn-on time and circular layout. Epoxy encapsulating was chosen to enhance the level of partial discharge initial voltage (PDIV). The combination of synchronous trigger and power supply is proposed to reduce the switch volume. Moreover, we have overcome the drawback of the electromagnetic interference and improved the detection sensitivity of DAC by using capacitor storage energy to maintain IGBT gate driving voltage. The experimental results demonstrated that the solid-state switch, with compact size, whose turn-on time was less than 400 ns and PDIV was more than 65 kV, was able to meet the actual demands of 35 kV DAC test system.

  15. Characterization of ionizing radiation effects in MOS structures by study of bipolar operation

    International Nuclear Information System (INIS)

    Bakhtiar, H.; Picard, C.; Brisset, C.; Bakhtiar, H.; Hoffmann, A.; Charles, J.P.

    1999-01-01

    This work presents an original method to characterize radiation effects of micronic transistors. The characterization includes a study of the transistor substrate-drain junction and current gain variation of the bipolar transistor (drain-substrate-source as emitter-base-collector) for different gate voltages. (authors)

  16. Non-ideal effect in 4H-SiC bipolar junction transistor with double Gaussian-doped base

    Science.gov (United States)

    Yuan, Lei; Zhang, Yu-Ming; Song, Qing-Wen; Tang, Xiao-Yan; Zhang, Yi-Men

    2015-06-01

    The non-ideal effect of 4H-SiC bipolar junction transistor (BJT) with a double Gaussian-doped base is characterized and simulated in this paper. By adding a specific interface model between SiC and SiO2, the simulation results are in good agreement with the experiment data. An obvious early effect is found from the output characteristic. As the temperature rises, the early voltage increases, while the current gain gradually decreases, which is totally different from the scenario of silicon BJT. With the same effective Gummel number in the base region, the double Gaussian-doped base structure can realize higher current gain than the single base BJT due to the built-in electric field, whereas the early effect will be more salient. Besides, the emitter current crowding effect is also analyzed. Due to the low sheet resistance in the first highly-doped base epilayer, the 4H-BJT with a double base has more uniform emitter current density across the base-emitter junction, leading to better thermal stability. Project supported by the National Natural Science Foundation of China (Grant Nos. 60876061 and 61234006), the Natural Science Foundation of Shaanxi Province, China (Grant No. 2013JQ8012), and the Doctoral Fund of the Ministry of Education of China (Grant Nos. 20130203120017 and 20110203110010).

  17. Improved performance of bipolar charge plasma transistor by reducing the horizontal electric field

    Science.gov (United States)

    Bramhane, Lokesh Kumar; Singh, Jawar

    2017-04-01

    In this paper, we have proposed a modified lateral bipolar charge plasma transistor (BCPT). The appropriate work function engineering is used to induce the electron-hole concentrations under different regions. The reduced work function difference and absence of oxide layer (tox) in the proposed lateral BCPT reduce the horizontal electric field (EX) at the emitter. Also, reduced work function difference at base metal contact decreases the electric field at base-emitter and base-collector junctions. 2-D TCAD simulations of the proposed device reveal that there are evenly spaced output characteristic curves, improved cut-off frequency and breakdown voltage. The reduction in horizontal electric field about one-fourth compared to the conventional lateral BCPT results in realistic current gain (β) and reduced on-set voltage makes proposed device suitable for low power applications. The proposed device exhibits improved cut-off frequency (fT = 7.5 GHz) compared to the lateral BCPT (3.7 GHz) and improved current gain (37.67) and same cut-off frequency (= 7.5 GHz) compared to the conventional BJT (β = 26.5 &fT = 7.5 GHz).

  18. GaAsP/InGaP heterojunction bipolar transistors grown by MOCVD

    Science.gov (United States)

    Heidelberger, Christopher; Fitzgerald, Eugene A.

    2017-01-01

    Heterojunction bipolar transistors with GaAsxP1-x bases and collectors and InyGa1-yP emitters were grown on GaAs substrates via metalorganic chemical vapor deposition, fabricated using conventional techniques, and electrically tested. Four different GaAsxP1-x compositions were used, ranging from x = 0.825 to x = 1 (GaAs), while the InyGa1-yP composition was adjusted to remain lattice-matched to the GaAsP. DC gain close to or exceeding 100 is measured for 60 μm diameter devices of all compositions. Physical mechanisms governing base current and therefore current gain are investigated. The collector current is determined not to be affected by the barrier caused by the conduction band offset between the InGaP emitter and GaAsP base. While the collector current for the GaAs/InGaP devices is well-predicted by diffusion of electrons across the quasi-neutral base, the collector current of the GaAsP/InGaP devices exceeds this estimate by an order of magnitude. This results in higher transconductance for GaAsP/InGaP than would be estimated from known material properties.

  19. Radiation damage and defects in NPN bipolar junction transistors irradiated by silicon ions with various energies

    Science.gov (United States)

    Liu, Chaoming; Zhang, Xiaodong; Yang, Jianqun; Li, Xingji; Ma, Guoliang

    2017-10-01

    The characteristic of incident particle is an important factor to evaluate the correlation of radiation damage. It is useful to investigate the influence of incident particle with various energies on radiation effects of BJTs. Radiation effects in bipolar junction transistors are examined under the irradiation with 10, 24 and 40 MeV Si ions in this paper. Based on the electrical performance degradation, it is shown that the change in the reciprocal of current gain is dominated by the ionizing damage during the heavy ion irradiations at low fluence, leading to a non-linear behavior. While at a higher fluence, displacement damage is the domain effect to show a linear curve. Deep level transient spectroscopy (DLTS) is used to analyze the characteristic of the deep level defects induced by irradiations. DLTS results show that for the BJTs under various Si ions irradiations, the types of deep level defects induced by Si ions are similar, while the concentration of the defects is different at the same displacement dose.

  20. Bipolar-power-transistor-based limiter for high frequency ultrasound imaging systems.

    Science.gov (United States)

    Choi, Hojong; Yang, Hao-Chung; Shung, K Kirk

    2014-03-01

    High performance limiters are described in this paper for applications in high frequency ultrasound imaging systems. Limiters protect the ultrasound receiver from the high voltage (HV) spikes produced by the transmitter. We present a new bipolar power transistor (BPT) configuration and compare its design and performance to a diode limiter used in traditional ultrasound research and one commercially available limiter. Limiter performance depends greatly on the insertion loss (IL), total harmonic distortion (THD) and response time (RT), each of which will be evaluated in all the limiters. The results indicated that, compared with commercial limiter, BPT-based limiter had less IL (-7.7 dB), THD (-74.6 dB) and lower RT (43 ns) at 100 MHz. To evaluate the capability of these limiters, they were connected to a 100 MHz single element transducer and a two-way pulse-echo test was performed. It was found that the -6 dB bandwidth and sensitivity of the transducer using BPT-based limiter were better than those of the commercial limiter by 22% and 140%, respectively. Compared to the commercial limiter, BPT-based limiter is shown to be capable of minimizing signal attenuation, RT and THD at high frequencies and is thus suited for high frequency ultrasound applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Tunneling Current of Electron in Armchair Graphene Nanoribbon Bipolar Transistor Model Using Transfer Matrix Method

    Science.gov (United States)

    Fahmi, A. K.; Hasanah, L.; Rusdiana, D.; Aminudin, A.; Suhendi, E.

    2017-03-01

    The tunneling current of n-p-n bipolar junction transistor AGNR-based is modeled with semi-numerical method. The exponential solution from Schrödinger equation is used and solved analytically. The potential profile of n-p-n BJT divided into several segments in the numerical method. Then, the solved analytical result is used in the numerical method to compute the electron transmittance. Transfer Matrix Method (TMM) is the numerical method used to compute the electron transmittance. From the calculated transmittance the tunneling current can be computed by using Landauer formula with aid of Gauss-Legendre Quadrature (GLQ). Next, the tunneling current is computed with several change of variables which are base-emitter voltage (VBE), base-collector voltage (VBC), temperature and the AGNR’s width. The computed tunneling current shows that the larger value of applied voltage for both VBE and VBC results in larger value of tunneling current. At the lower temperature, the current is larger. The computed tunneling current shows that at wider width of AGNR, the current is also larger. This is due to the decreased band-gap energy (Eg) because of the wider width of AGNR.

  2. Junction-to-Case Thermal Resistance of a Silicon Carbide Bipolar Junction Transistor Measured

    Science.gov (United States)

    Niedra, Janis M.

    2006-01-01

    Junction temperature of a prototype SiC-based bipolar junction transistor (BJT) was estimated by using the base-emitter voltage (V(sub BE)) characteristic for thermometry. The V(sub BE) was measured as a function of the base current (I(sub B)) at selected temperatures (T), all at a fixed collector current (I(sub C)) and under very low duty cycle pulse conditions. Under such conditions, the average temperature of the chip was taken to be the same as that of the temperature-controlled case. At increased duty cycle such as to substantially heat the chip, but same I(sub C) pulse height, the chip temperature was identified by matching the V(sub BE) to the thermometry curves. From the measured average power, the chip-to-case thermal resistance could be estimated, giving a reasonable value. A tentative explanation for an observed bunching with increasing temperature of the calibration curves may relate to an increasing dopant atom ionization. A first-cut analysis, however, does not support this.

  3. Effect of bias condition on heavy ion radiation in bipolar junction transistors

    Science.gov (United States)

    Liu, Chao-Ming; Li, Xing-Ji; Geng, Hong-Bin; Yang, De-Zhuang; He, Shi-Yu

    2012-08-01

    The characteristic degradations in a silicon NPN bipolar junction transistor (BJT) of 3DG142 type are examined under irradiation with 40-MeV chlorine (Cl) ions under forward, grounded, and reverse bias conditions, respectively. Different electrical parameters are in-situ measured during the exposure under each bias condition. From the experimental data, a larger variation of base current (IB) is observed after irradiation at a given value of base-emitter voltage (VBE), while the collector current is slightly affected by irradiation at a given VBE. The gain degradation is affected mostly by the behaviour of the base current. From the experimental data, the variation of current gain in the case of forward bias is much smaller than that in the other conditions. Moreover, for 3DG142 BJT, the current gain degradation in the case of reverse bias is more severe than that in the grounded case at low fluence, while at high fluence, the gain degradation in the reverse bias case becomes smaller than that in the grounded case.

  4. Bipolar junction transistor as a detector for measuring in diagnostic X-ray beams

    Energy Technology Data Exchange (ETDEWEB)

    Cavalcanti, Francisco A.; Monte, David S.; Alves, Aline N.; Barros, Fabio R.; Santos, Marcus A.P.; Santos, Luiz A.P., E-mail: franciscoacavalcanti@gmail.com, E-mail: lasantos@cnen.gov.br [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2013-07-01

    Photodiode and phototransistor are the most frequently used devices for measuring ionizing radiation in medical applications. The cited devices have the operating principle well known, however the bipolar junction transistor (BJT) is not a typical device used as a detector for measuring some physical quantities for diagnostic radiation. In fact, a photodiode, for example, has an area about 10 mm square and a BJT has an area which can be more than 10 thousands times smaller. The purpose of this paper is to bring a new technique to estimate some physical quantities or parameters in diagnostic radiation; for example, peak kilovoltage (kVp), deep dose measurements. The methodology for each type of evaluation depends on the energy range of the radiation and the physical quantity or parameter to be measured. Actually, some characteristics of the incident radiation under the device can be correlated with the readout signal, which is a function of the electrical currents in the electrodes of the BJT: Collector, Base and Emitter. Samples of BJT are classified and submitted to diagnostic X-ray beams. The results show that the BJT could be a new semiconductor sensor type for measuring either the ionizing radiation dose or some characteristics of diagnostic X-ray beams. (author)

  5. Three-terminal heterojunction bipolar transistor solar cell for high-efficiency photovoltaic conversion

    OpenAIRE

    Martí Vega, Antonio; Luque López, Antonio

    2015-01-01

    Here we propose, for the first time, a solar cell characterized by a semiconductor transistor structure (n/p/n or p/n/p) where the base?emitter junction is made of a high-bandgap semiconductor and the collector is made of a low-bandgap semiconductor. We calculate its detailed-balance efficiency limit and prove that it is the same one than that of a double-junction solar cell. The practical importance of this result relies on the simplicity of the structure that reduces the number of layers th...

  6. Influence of the flux density on the radiation damage of bipolar silicon transistors by protons and electrons

    International Nuclear Information System (INIS)

    Bannikov, Y.; Gorin, B.; Kozhevnikov, V.; Mikhnovich, V.; Gusev, L.

    1981-01-01

    It was found experimentally that the radiation damage of bipolar n-p-n transistors increased by a factor of 8--12 when the proton flux density was reduced from 4.07 x 10 10 to 2.5 x 10 7 cm -2 sec -1 . In the case of p-n-p transistors the effect was opposite: there was a reduction in the radiation damage by a factor of 2--3 when the dose rate was lowered between the same limits. A similar effect was observed for electrons but at dose rates three orders of magnitude greater. The results were attributed to the dependences of the radiation defect-forming reactions on the charge state of defects which was influenced by the formation of disordered regions in the case of proton irradiation

  7. Effect of parasitic series resistances and spurious currents on the extracted temperature of a bipolar junction transistor.

    Science.gov (United States)

    Mimila-Arroyo, J

    2013-12-01

    Verster's proposition to directly extract the temperature of a bipolar junction transistor using its collector current is widely used. However, the resulting temperature is low accurate even when calibrated. Here, it is demonstrated that the misuse of the emitter current instead of the collector one, because of the presence of spurious currents other than the injection-diffusion one and transistor parasitic series resistances both contribute to the observed inaccuracy. Particularly parasitic series resistances increase the inaccuracy and introduce a strong dependence of the extracted temperature on the collector currents used to extract the temperature; the higher those resistances the higher the inaccuracy. A proposition is made to reduce the effect of those resistances on the inaccuracy of this thermometric element, which allows obtaining a more accurate value on a wider range of the collector probe currents.

  8. A Logarithmic Response Complementary Metal Oxide Semiconductor Image Sensor with Parasitic P-N-P Bipolar Junction Transistor

    Science.gov (United States)

    Lai, Cheng‑Hsiao; Lai, Liang‑Wei; Chiang, Wen‑Jen; King, Ya‑Chin

    2006-04-01

    Logarithmic-response complementary metal oxide semiconductor (CMOS) active pixel sensors provide a desirable attribute of wide dynamic range even with low supply voltages. In this paper, a log-mode pixel with employing parasitic P-N-P bipolar junction transistor (BJT) to amplify photo-current is investigated and optimized. A new log-mode cell with a calibration transistor is proposed to increase the output voltage swing as well as to reduce the fixed pattern noise. The measurement results demonstrate that, the output voltage swing of this new cell is enhanced by 4× and fixed pattern noise (FPN) of a pixel array can be reduced by 10× comparing to that of a conventional log-mode CMOS active pixel sensor.

  9. Characteristics of Novel InGaAsN Double Heterojunction Bipolar Transistors

    Energy Technology Data Exchange (ETDEWEB)

    LI,N.Y.; CHANG,PING-CHIH; BACA,ALBERT G.; LAROCHE,J.R.; REN,F.; ARMOUR,E.; SHARPS,P.R.; HOU,H.Q.

    2000-08-01

    The authors demonstrate, for the first time, both functional Pnp AlGaAs/InGaAsN/GaAs (Pnp InGaAsN) and Npn InGaP/InGaAsN/GaAs (Npn InGaAsN) double heterojunction bipolar transistors (DHBTs) using a 1.2 eV In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} as the base layer for low-power electronic applications. The Pnp InGaAsN DHBT has a peak current gain ({beta}) of 25 and a low turn-on voltage (V{sub ON}) of 0.79 V. This low V{sub ON} is {approximately} 0.25 V lower than in a comparable Pnp AlGAAs/GaAs HBT. For the Npn InGaAsN DHBT, it has a low V{sub ON} of 0.81 V, which is 0.13 V lower than in an InGaP/GaAs HBT. A peak {beta} of 7 with nearly ideal I-V characteristics has been demonstrated. Since GaAs is used as the collector of both Npn and Pnp InGaAsN DHBTs, the emitter-collector breakdown voltage (BV{sub CEO}) are 10 and 12 V, respectively, consistent with the BV{sub CEO} of Npn InGaP/GaAs and Pnp AlGaAs/GaAs HBTs of comparable collector thickness and doping level. All these results demonstrate the potential of InGaAsN DHBTs as an alternative for application in low-power electronics.

  10. Switching Characteristics of a 4H-SiC Based Bipolar Junction Transistor to 200 C

    Science.gov (United States)

    Niedra, Janis M.

    2006-01-01

    Static curves and resistive load switching characteristics of a 600 V, 4 A rated, SiC-based NPN bipolar power transistor (BJT) were observed at selected temperatures from room to 200 C. All testing was done in a pulse mode at low duty cycle (approx.0.1 percent). Turn-on was driven by an adjustable base current pulse and turn-off was accelerated by a negative base voltage pulse of 7 V. These base drive signals were implemented by 850 V, gated power pulsers, having rise-times of roughly 10 ns, or less. Base charge sweep-out with a 7 V negative pulse did not produce the large reverse base current pulse seen in a comparably rated Si-based BJT. This may be due to a very low charge storage time. The decay of the collector current was more linear than its exponential-like rise. Switching observations were done at base drive currents (I(sub B)) up to 400 mA and collector currents (I(sub C)) up to 4 A, using a 100 Omega non-inductive load. At I(sub B) = 400 mA and I(sub C) = 4 A, turn-on times typically varied from 80 to 94 ns, over temperatures from 23 to 200 C. As expected, lowering the base drive greatly extended the turn-on time. Similarly, decreasing the load current to I(sub C) = 1 A with I(sub B) = 400 mA produced turn-on times as short as 34 ns. Over the 23 to 200 C range, with I(sub B) = 400 mA and I(sub C) = 4 A, turn-off times were in the range of 72 to 84 ns with the 7 V sweep-out.

  11. The mixed-mode reliability stress of silicon-germanium heterojunction bipolar transistors

    Science.gov (United States)

    Zhu, Chendong

    The objective of the dissertation is to combine the recent Mixed-Mode reliability stress studies in silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs). The thesis starts with a review of SiGe HBT fundamentals, development trends, and the conventional reliability stress paths used in industry, following which the new stress path, Mixed-Mode stress, is introduced. Chapter 2 is devoted to an in-depth discussion of damage mechanisms that includes the impact ionization effect and the self-heating effect. Chapter 3 goes onto the impact ionization effect using two-dimensional calibrated MEDICI simulations. Chapter 4 assesses the reliability of SiGe HBTs in extreme temperature environments by way of comprehensive experiments and MEDICI simulations. A comparison of the device lifetimes for reverse-EB stress and mixed-mode stress indicates different damage mechanisms govern these phenomena. The thesis concludes with a summary of the project and suggestions for future research in chapter 5. This dissertation covers the following topics: (1) Introduces a new mixed-mode stress technique: time cumulative stress (Chapter II, also published in [23] and [24]). (2) Identifies impact ionization effects in the stress damage (Chapter II, also published in [23] and [24]). (3) Investigates for the first time mixed-mode damage using TCAD simulations at both room temperature and cryogenic temperatures (Chapter III and IV, also published in [23][24][62]). (4) Analyzes for the first time impact of self-heating on mixed-mode stress response, and identifies a temperature triggered damage threshold (Chapter II, will be published in [25]). (5) Explains the geometrical scaling issues in mixed-mode stress and explores mixed-mode stress reliability scaling trends (Chapter II, will be published in [25]). (6) Assesses for the first time SiGe HBT reliability at cryogenic temperatures (Chapter VI, also published in [62]).

  12. The high temperature DC characteristics of a high voltage lateral insulated-gate bipolar transistors with NPN anode in junction isolation technology

    Science.gov (United States)

    Tsai, Ying-Chieh; Gong, Jeng; Chan, Wing-Chor; Wu, Shyi-Yuan; Lien, Chenhsin

    2017-06-01

    The high temperature DC characteristics of a high-voltage bulk Si lateral insulated-gate bipolar transistor in junction isolation (JI-LIGBT) technology is studied intensively in this paper. The current density distribution in the off-state at different temperatures of three types of device structure is compared. By using the Quasi-vertical DMOSFET (QVDMOS or multi-channel, MC) structure, the electron injection from the channel into the n-drift region is significantly enhanced, and the current density is improved. In addition, by extending the p-top layer to the NPN anode not only improves the breakdown voltage but also reduces the substrate current as well as ensures high temperature stability.

  13. A comparative study on electrical characteristics of 1-kV pnp and npn SiC bipolar junction transistors

    Science.gov (United States)

    Okuda, Takafumi; Kimoto, Tsunenobu; Suda, Jun

    2018-04-01

    We investigate the electrical characteristics of 1-kV pnp SiC bipolar junction transistors (BJTs) and compare them with those of npn SiC BJTs. The base resistance, current gain, and blocking capability are characterized. It is found that the base resistance of pnp SiC BJTs is two orders of magnitude lower than that of npn SiC BJTs. However, the obtained current gains are low below unity in pnp SiC BJTs, whereas npn SiC BJTs exhibit a current gain of 14 without surface passivation. The reason for the poor current gain of pnp SiC BJTs is discussed.

  14. Impact ionization in the base of a hot-electron AlSb/InAs bipolar transistor

    Science.gov (United States)

    Vengurlekar, Arvind S.; Capasso, Federico; Chiu, T. Heng

    1990-01-01

    The operation of a new AlSb/InAs heterojunction bipolar transistor is studied. The electrons are injected into a p-InAs base across the AlSb/InAs heterojunction. The conduction-band discontinuity at this heterojunction is sufficiently large so that energy of the electrons injected into InAs exceeds the threshold for generating electron-hole pairs by impact ionization. The observed incremental common base current at zero collector-base bias decreases and becomes negative as the emitter current is increased, thus providing direct evidence for impact ionization entirely by band-edge discontinuities.

  15. On the choice of a head element for low-noise bipolar transistor amplifier

    International Nuclear Information System (INIS)

    Krasnokutskij, R.N.; Kurchaninov, L.L.; Fedyakin, N.N.; Shuvalov, R.S.

    1988-01-01

    The measurement results of equivalent noise charge (ENC) for KT382 transistor depending on detector capacity, formation duration and collector current are given. It is shown that the measurement results for this transistor in good agreement with calculations according to the noise model, time-consuming ENC measurements can be replaced by preliminary transistor rejection according to the distributed base resistance, current gain and simple calculations. In applications in the field of nuclear electronics the KT382 transistor enables to attain the same noise parameters as NE578, NE021 transistors (Japan) and it can be recommended for using as a head element of amplifiers

  16. Three-terminal heterojunction bipolar transistor solar cell for high-efficiency photovoltaic conversion.

    Science.gov (United States)

    Martí, A; Luque, A

    2015-04-22

    Here we propose, for the first time, a solar cell characterized by a semiconductor transistor structure (n/p/n or p/n/p) where the base-emitter junction is made of a high-bandgap semiconductor and the collector is made of a low-bandgap semiconductor. We calculate its detailed-balance efficiency limit and prove that it is the same one than that of a double-junction solar cell. The practical importance of this result relies on the simplicity of the structure that reduces the number of layers that are required to match the limiting efficiency of dual-junction solar cells without using tunnel junctions. The device naturally emerges as a three-terminal solar cell and can also be used as building block of multijunction solar cells with an increased number of junctions.

  17. Three-terminal heterojunction bipolar transistor solar cell for high-efficiency photovoltaic conversion

    Science.gov (United States)

    Martí, A.; Luque, A.

    2015-04-01

    Here we propose, for the first time, a solar cell characterized by a semiconductor transistor structure (n/p/n or p/n/p) where the base-emitter junction is made of a high-bandgap semiconductor and the collector is made of a low-bandgap semiconductor. We calculate its detailed-balance efficiency limit and prove that it is the same one than that of a double-junction solar cell. The practical importance of this result relies on the simplicity of the structure that reduces the number of layers that are required to match the limiting efficiency of dual-junction solar cells without using tunnel junctions. The device naturally emerges as a three-terminal solar cell and can also be used as building block of multijunction solar cells with an increased number of junctions.

  18. Three-dimensional simulation of fabrication process-dependent effects on single event effects of SiGe heterojunction bipolar transistor

    International Nuclear Information System (INIS)

    Zhang Jin-Xin; Guo Bao-Long; Wu Xian-Xiang; He Chao-Hui; Li Pei; Guo Hong-Xia

    2017-01-01

    The fabrication process dependent effects on single event effects (SEEs) are investigated in a commercial silicon–germanium heterojunction bipolar transistor (SiGe HBT) using three-dimensional (3D) TCAD simulations. The influences of device structure and doping concentration on SEEs are discussed via analysis of current transient and charge collection induced by ions strike. The results show that the SEEs representation of current transient is different from representation of the charge collection for the same process parameters. To be specific, the area of C/S junction is the key parameter that affects charge collection of SEE. Both current transient and charge collection are dependent on the doping of collector and substrate. The base doping slightly influences transient currents of base, emitter, and collector terminals. However, the SEEs of SiGe HBT are hardly affected by the doping of epitaxial base and the content of Ge. (paper)

  19. Two-zone SiGe base heterojunction bipolar charge plasma transistor for next generation analog and RF applications

    Science.gov (United States)

    Bramhane, Lokesh Kumar; Singh, Jawar

    2017-01-01

    For next generation terahertz applications, heterojunction bipolar transistor (HBT) with reduced dimensions and charge plasma (CP) can be a potential candidate due to simplified and inexpensive process. In this paper, a symmetric lateral two-zone SiGe base heterojunction bipolar charge plasma transistor (HBCPT) with an extruded (extended) base is proposed and its performance at circuit level is studied. The linearly graded electric field in the proposed HBCPT provides improved self gain (β) and cut-off frequency (fT). Two-dimensional (2-D) TCAD and small-signal model based simulations of the proposed HBCPT demonstrates high self gain β 35-172.93 and fT of 1-4 THz for different device parameters. Moreover, fT of 1104.9 GHz and β of 35 can be achieved by decreasing Nb up to 8.2 ×1017cm-3 . Although, fT of 2 THz and 4 THz can also be achieved by reducing the base resistance up to 10 Ω and increasing the emitter/collector length up to 63 nm, respectively. The small-signal analysis of common-emitter amplifier based on the proposed HBCPT demonstrate high voltage gain of 50.11 as compared to conventional HBT (18.1).

  20. Analysis of the dynamic avalanche of carrier stored trench bipolar transistor (CSTBT) during clamped inductive turn-off transient

    Science.gov (United States)

    Xue, Peng; Fu, Guicui

    2017-03-01

    The dynamic avalanche has a huge impact on the switching robustness of carrier stored trench bipolar transistor (CSTBT). The purpose of this work is to investigate the CSTBT's dynamic avalanche mechanism during clamped inductive turn-off transient. At first, with a Mitsubishi 600 V/150 A CSTBT and a Infineon 600 V/200 A field stop insulated gate bipolar transistor (FS-IGBT) utilized, the clamped inductive turn-off characteristics are obtained by double pulse test. The unclamped inductive switching (UIS) test is also utilized to identify the CSTBT's clamping voltage under dynamic avalanche condition. After the test data analysis, it is found that the CSTBT's dynamic avalanche is abnormal and can be triggered under much looser condition than the conventional buffer layer IGBT. The comparison between the FS-IGBT and CSTBT's experimental results implies that the CSTBT's abnormal dynamic avalanche phenomenon may be induced by the carrier storage (CS) layer. Based on the semiconductor physics, the electric field distribution and dynamic avalanche generation in the depletion region are analyzed. The analysis confirms that the CS layer is the root cause of the CSTBT's abnormal dynamic avalanche mechanism. Moreover, the CSTBT's negative gate capacitance effect is also investigated to clarify the underlying mechanism of the gate voltage bump observed in the test. In the end, the mixed-mode numerical simulation is utilized to reproduce the CSTBT's dynamic avalanche behavior. The simulation results validate the proposed dynamic avalanche mechanisms.

  1. Low Gate Voltage Operated Multi-emitter-dot H+ Ion-Sensitive Gated Lateral Bipolar Junction Transistor

    Science.gov (United States)

    Yuan, Heng; Zhang, Ji-Xing; Zhang, Chen; Zhang, Ning; Xu, Li-Xia; Ding, Ming; Patrick, J. Clarke

    2015-02-01

    A low gate voltage operated multi-emitter-dot gated lateral bipolar junction transistor (BJT) ion sensor is proposed. The proposed device is composed of an arrayed gated lateral BJT, which is driven in the metal-oxide-semiconductor field-effect transistor (MOSFET)-BJT hybrid operation mode. Further, it has multiple emitter dots linked to each other in parallel to improve ionic sensitivity. Using hydrogen ionic solutions as reference solutions, we conduct experiments in which we compare the sensitivity and threshold voltage of the multi-emitter-dot gated lateral BJT with that of the single-emitter-dot gated lateral BJT. The multi-emitter-dot gated lateral BJT not only shows increased sensitivity but, more importantly, the proposed device can be operated under very low gate voltage, whereas the conventional ion-sensitive field-effect transistors cannot. This special characteristic is significant for low power devices and for function devices in which the provision of a gate voltage is difficult.

  2. Improvement of Current Gain in Triple Ion Implanted 4H-SiC Bipolar Junction Transistor with Etched Extrinsic Base Regions

    Science.gov (United States)

    Tajima, Taku; Nakamura, Tadashi; Satoh, Masataka; Nakamura, Tohru

    We demonstrate triple ion implanted 4H-SiC bipolar junction transistor (BJT). By etching the extrinsic base regions using inductively coupled plasma dry etching, the characteristics of triple ion implanted 4H-SiC BJT were significantly improved. Maximum common emitter current gain was improved from 1.7 to 7.5.

  3. Gate voltage dependent characteristics of p-n diodes and bipolar transistors based on multiwall CN(x)/carbon nanotube intramolecular junctions.

    Science.gov (United States)

    Zhang, W J; Zhang, Q F; Chai, Y; Shen, X; Wu, J L

    2007-10-03

    The electrical transport characteristics of multiwall CN(x)/carbon nanotube intramolecular junctions were studied. The junctions could be used as diodes. We found that the rectification resulted from p-n junctions, not from metal-semiconductor junctions. The gate effect was very weak when the diodes were reverse biased. At forward bias, however, some of the p-n diodes could be n-type transistors. Experimental results supported the opinion that the gate voltage dependent property is derived from the Schottky barrier between the CN(x) part and the electrode. Using p-n diodes, a bipolar transistor with nanoscale components was built, whose behavior was very similar to that of a conventional planar bipolar transistor.

  4. Optimization of Vertical Double-Diffused Metal-Oxide Semiconductor (VDMOS) Power Transistor Structure for Use in High Frequencies and Medical Devices.

    Science.gov (United States)

    Farhadi, Rozita; Farhadi, Bita

    2014-01-01

    Power transistors, such as the vertical, double-diffused, metal-oxide semiconductor (VDMOS), are used extensively in the amplifier circuits of medical devices. The aim of this research was to construct a VDMOS power transistor with an optimized structure to enhance the operation of medical devices. First, boron was implanted in silicon by implanting unclamped inductive switching (UIS) and a Faraday shield. The Faraday shield was implanted in order to replace the gate-field parasitic capacitor on the entry part of the device. Also, implanting the UIS was used in order to decrease the effect of parasitic bipolar junction transistor (BJT) of the VDMOS power transistor. The research tool used in this study was Silvaco software. By decreasing the transistor entry resistance in the optimized VDMOS structure, power losses and noise at the entry of the transistor were decreased, and, by increasing the breakdown voltage, the lifetime of the VDMOS transistor lifetime was increased, which resulted in increasing drain flow and decreasing Ron. This consequently resulted in enhancing the operation of high-frequency medical devices that use transistors, such as Radio Frequency (RF) and electrocardiograph machines.

  5. Improved methods of forming monolithic integrated circuits having complementary bipolar transistors

    Science.gov (United States)

    Bohannon, R. O., Jr.; Cashion, W. F.; Stehlin, R. A.

    1971-01-01

    Two new processes form complementary transistors in monolithic semiconductor circuits, require fewer steps /infusions/ than previous methods, and eliminate such problems as nonuniform h sub FE distribution, low yield, and large device formation.

  6. EMP injection damage effects of a bipolar transistor and its relationship between the injecting voltage and energy

    International Nuclear Information System (INIS)

    Xi Xiaowen; Chai Changchun; Ren Xingrong; Yang Yintang; Zhang Bing; Hong Xiao

    2010-01-01

    The response of a bipolar transistor (BJT) under a square-wave electromagnetic pulse (EMP) with different injecting voltages is investigated. Adopting the curve fitting method, the relationship between the burnout time, the damage energy and the injecting voltage is obtained. Research shows that the damage energy is not a constant value, but changes with the injecting voltage level. By use of the device simulator Medici, the internal behavior of the burned device is analyzed. Simulation results indicate that the variation of the damage energy with injecting voltage is caused by the distribution change of hot spot position under different injection levels. Therefore, the traditional way to evaluate the trade-off between the burnout time and the injecting voltage is not comprehensive due to the variation of the damage energy. (semiconductor devices)

  7. SEMICONDUCTOR DEVICES: EMP injection damage effects of a bipolar transistor and its relationship between the injecting voltage and energy

    Science.gov (United States)

    Xiaowen, Xi; Changchun, Chai; Xingrong, Ren; Yintang, Yang; Bing, Zhang; Xiao, Hong

    2010-04-01

    The response of a bipolar transistor (BJT) under a square-wave electromagnetic pulse (EMP) with different injecting voltages is investigated. Adopting the curve fitting method, the relationship between the burnout time, the damage energy and the injecting voltage is obtained. Research shows that the damage energy is not a constant value, but changes with the injecting voltage level. By use of the device simulator Medici, the internal behavior of the burned device is analyzed. Simulation results indicate that the variation of the damage energy with injecting voltage is caused by the distribution change of hot spot position under different injection levels. Therefore, the traditional way to evaluate the trade-off between the burnout time and the injecting voltage is not comprehensive due to the variation of the damage energy.

  8. EMP injection damage effects of a bipolar transistor and its relationship between the injecting voltage and energy

    Energy Technology Data Exchange (ETDEWEB)

    Xi Xiaowen; Chai Changchun; Ren Xingrong; Yang Yintang; Zhang Bing; Hong Xiao, E-mail: xixiaowen523103@163.co [Key Laboratory of Ministry of Education for Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi' an 710071 (China)

    2010-04-15

    The response of a bipolar transistor (BJT) under a square-wave electromagnetic pulse (EMP) with different injecting voltages is investigated. Adopting the curve fitting method, the relationship between the burnout time, the damage energy and the injecting voltage is obtained. Research shows that the damage energy is not a constant value, but changes with the injecting voltage level. By use of the device simulator Medici, the internal behavior of the burned device is analyzed. Simulation results indicate that the variation of the damage energy with injecting voltage is caused by the distribution change of hot spot position under different injection levels. Therefore, the traditional way to evaluate the trade-off between the burnout time and the injecting voltage is not comprehensive due to the variation of the damage energy. (semiconductor devices)

  9. 2D device-level simulation study of strained-Si pnp heterojunction bipolar transistors on virtual substrates

    Science.gov (United States)

    Jankovic, N. D.; O'Neill, A.

    2004-02-01

    A novel strained-Si pnp heterojunction bipolar transistor (HBT) design, suitable for virtual substrate technology, is proposed that is inherently free from the detrimental valence band barrier effects usually encountered in conventional SiGe pnp HBTs on silicon. It takes advantage of the heterojunction formed between a strained-Si layer and a relaxed SiGe buffer (virtual substrate), whose associated valence band offset appears favorable for minority hole transport at the base/collector junction. From two-dimensional (2D) numerical simulation, it is found that the newly proposed strained-Si pnp HBT substantially outperforms the equivalent BJT on a silicon substrate in terms of DC and high-frequency characteristics. A threefold increase in maximum current gain β, a fourfold improvement in peak ft and a 2.5 times increase in peak fmax are predicted for strained-Si pnp HBTs on a 50% Ge virtual substrate in comparison with identical conventional silicon pnp BJTs.

  10. Simultaneous integration of MOS and bipolar transistors. Application to a fast complex memory

    International Nuclear Information System (INIS)

    Mackowiak, E.; Montier, M.

    1975-01-01

    A technology allowing for a simultaneous integration of two devices T MOS and T BIP (bipolar T) is presented. The technological results obtained and an application in the field of fast complex memories are given [fr

  11. MOSFET-BJT hybrid mode of the gated lateral bipolar junction transistor for C-reactive protein detection.

    Science.gov (United States)

    Yuan, Heng; Kwon, Hyurk-Choon; Yeom, Se-Hyuk; Kwon, Dae-Hyuk; Kang, Shin-Won

    2011-10-15

    In this study, we propose a novel biosensor based on a gated lateral bipolar junction transistor (BJT) for biomaterial detection. The gated lateral BJT can function as both a BJT and a metal-oxide-semiconductor field-effect transistor (MOSFET) with both the emitter and source, and the collector and drain, coupled. C-reactive protein (CRP), which is an important disease marker in clinical examinations, can be detected using the proposed device. In the MOSFET-BJT hybrid mode, the sensitivity, selectivity, and reproducibility of the gated lateral BJT for biosensors were evaluated in this study. According to the results, in the MOSFET-BJT hybrid mode, the gated lateral BJT shows good selectivity and reproducibility. Changes in the emitter (source) current of the device for CRP antigen detection were approximately 0.65, 0.72, and 0.80 μA/decade at base currents of -50, -30, and -10 μA, respectively. The proposed device has significant application in the detection of certain biomaterials that require a dilution process using a common biosensor, such as a MOSFET-based biosensor. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Annealing effects and DLTS study on PNP silicon bipolar junction transistors irradiated by 20 MeV Br ions

    Science.gov (United States)

    Liu, Chaoming; Li, Xingji; Yang, Jianqun; Bollmann, Joachim

    2014-01-01

    Isochronal anneal sequences have been carried out on 3CG130 silicon PNP bipolar junction transistors (BJTs) irradiated with 20 MeV bromine (Br) heavy ions. The Gummel curve was utilized to characterize the annealing behavior of defects in both the emitter-base depletion region and the neutral base. The results show that the base current (IB) decreases with the increasing annealing temperature, while the collector current (IC) keeps invariably. The current gain varies slightly, when the annealing temperature (TA) is lower than 500 K, while varies rapidly at TA>550 K, and the current gain of the 3CG130 BJT annealing at 700 K almost restore to that of the pre-radiation transistor. The deep level transient spectroscopy (DLTS) data was used to assign the relative magnitude of each of the important defects. Based on the in situ electrical measurement and DLTS spectra, it is clear that the V2(+/0) trap is the main contribution to the degradation of current gain after the 20 MeV Br ions irradiation. The V2(+/0) peak has many characteristics expected for the current gain degradation.

  13. Annealing effects and DLTS study on PNP silicon bipolar junction transistors irradiated by 20 MeV Br ions

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chaoming [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Li, Xingji, E-mail: lxj0218@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Yang, Jianqun [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Bollmann, Joachim [Institute of Electronics and Sensor Materials, TU Bergakademie, Freiberg 71691 (Germany)

    2014-01-21

    Isochronal anneal sequences have been carried out on 3CG130 silicon PNP bipolar junction transistors (BJTs) irradiated with 20 MeV bromine (Br) heavy ions. The Gummel curve was utilized to characterize the annealing behavior of defects in both the emitter-base depletion region and the neutral base. The results show that the base current (I{sub B}) decreases with the increasing annealing temperature, while the collector current (I{sub C}) keeps invariably. The current gain varies slightly, when the annealing temperature (T{sub A}) is lower than 500 K, while varies rapidly at T{sub A}>550 K, and the current gain of the 3CG130 BJT annealing at 700 K almost restore to that of the pre-radiation transistor. The deep level transient spectroscopy (DLTS) data was used to assign the relative magnitude of each of the important defects. Based on the in situ electrical measurement and DLTS spectra, it is clear that the V{sub 2}(+/0) trap is the main contribution to the degradation of current gain after the 20 MeV Br ions irradiation. The V{sub 2}(+/0) peak has many characteristics expected for the current gain degradation.

  14. Extreme Temperature Performance of Automotive-Grade Small Signal Bipolar Junction Transistors

    Science.gov (United States)

    Boomer, Kristen; Damron, Benny; Gray, Josh; Hammoud, Ahmad

    2018-01-01

    Electronics designed for space exploration missions must display efficient and reliable operation under extreme temperature conditions. For example, lunar outposts, Mars rovers and landers, James Webb Space Telescope, Europa orbiter, and deep space probes represent examples of missions where extreme temperatures and thermal cycling are encountered. Switching transistors, small signal as well as power level devices, are widely used in electronic controllers, data instrumentation, and power management and distribution systems. Little is known, however, about their performance in extreme temperature environments beyond their specified operating range; in particular under cryogenic conditions. This report summarizes preliminary results obtained on the evaluation of commercial-off-the-shelf (COTS) automotive-grade NPN small signal transistors over a wide temperature range and thermal cycling. The investigations were carried out to establish a baseline on functionality of these transistors and to determine suitability for use outside their recommended temperature limits.

  15. Nondestructive characterization of RBSOA of high-power bipolar transistors. [Reverse-bias safe operating area

    Science.gov (United States)

    Jovanovic, M. M.; Lee, F. C.; Chen, D. Y.

    1986-01-01

    Reverse-bias safe operating area (RBSOA) of high-power Darlington transistors is characterized using a 120 A/1000 V nondestructive reverse-bias second breakdown tester designed and fabricated at Virginia Polytechnic Institute and State University. Elaborate RBSOA characteristics are generated with different forward/reverse base drives and collector current levels. The effects of elevated case temperature and second-base drive on RBSOA of four-terminal Darlington devices are also discussed.

  16. Frequency pressure transducer with a sensitivity of mem capacitor on the basis of transistor structure with negative resistance

    Science.gov (United States)

    Osadchuk, Oleksandr V.; Osadchuk, Iaroslav O.; Suleimenov, Batyrbek; Zyska, Tomasz; Arman, Abenov; Tleshova, Akmaral; GrÄ dz, Å.»aklin

    2017-08-01

    In the article the pressure transducer with frequency output based on the structure of the bipolar-field transistors with negative resistance and tenso sensitive MEMS capacitor has been considered. A mathematical model of the frequency pressure transducer in dynamic regime has been developed that allowed to determine the voltage or current in the circuit at any given moment in time when acting this pressure. Analytical expressions of the conversion function and sensitivity equation has been received. The sensitivity of the developed device is between 0,95kHz/kPa to 1,65kHz/kPa.

  17. Comments on determination of bandgap narrowing from activation plots. [for bipolar transistors

    Science.gov (United States)

    Park, J.-S.; Neugroschel, A.; Lindholm, F. A.

    1986-01-01

    A determination is made of the temperature-dependence of emitter saturation current in bipolar devices which allows the derivation of a value for bandgap narrowing that is in better agreement with other determinations than previous results based on ohmic contact measurements of temperature dependence. The new values were obtained by varying the surface recombination velocity at the emitter surface. This improves accuracy by varying the minority carrier surface recombination velocity at the emitter contacts of otherwise indistinguishable emitters.

  18. Improvement of Switching Speed of a 600-V Nonpunch-Through Insulated Gate Bipolar Transistor Using Fast Neutron Irradiation

    Directory of Open Access Journals (Sweden)

    Ha Ni Baek

    2017-02-01

    Full Text Available Fast neutron irradiation was used to improve the switching speed of a 600-V nonpunch-through insulated gate bipolar transistor. Fast neutron irradiation was carried out at 30-MeV energy in doses of 1 × 108 n/cm2, 1 × 109 n/cm2, 1 × 1010 n/cm2, and 1 × 1011 n/cm2. Electrical characteristics such as current–voltage, forward on-state voltage drop, and switching speed of the device were analyzed and compared with those prior to irradiation. The on-state voltage drop of the initial devices prior to irradiation was 2.08 V, which increased to 2.10 V, 2.20 V, 2.3 V, and 2.4 V, respectively, depending on the irradiation dose. This effect arises because of the lattice defects generated by the fast neutrons. In particular, the turnoff delay time was reduced to 92 nanoseconds, 45% of that prior to irradiation, which means there is a substantial improvement in the switching speed of the device.

  19. A Fast-Acting Diagnostic Algorithm of Insulated Gate Bipolar Transistor Open Circuit Faults for Power Inverters in Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Lei Yu

    2017-04-01

    Full Text Available To improve the diagnostic detection speed in electric vehicles, a novel diagnostic algorithm of insulated gate bipolar transistor (IGBT open circuit faults for power inverters is proposed in this paper. The average of the difference between the actual three-phase current and referential three-phase current values over one electrical period is used as the diagnostic variable. The normalization method based on the amplitude of the d-q axis referential current is applied to the diagnostic variables to improve the response speed of diagnosis, and to avoid the noise and the delay caused by signal acquisition. In the parameter discretization process, the variable parameter moving average method (VPMAM is adopted to solve the variation of the average value over a period with the speed of the motor; hence, the diagnostic reliability of the system is improved. This algorithm is robust, independent of load variations, and has a high resistivity against false alarms. Since only the three-phase current of the motor is utilized for calculations in the time domain, a fast diagnostic detection speed can be achieved, which is significantly essential for real-time control in electric vehicles. The effectiveness of the proposed algorithm is verified by both simulation and experimental results.

  20. Simulation of energy and fluence dependence of heavy ion induced displacement damage factor in bipolar junction transistor

    Science.gov (United States)

    Kulkarni, S. R.; Ravindra, M.; Joshi, G. R.; Damle, R.

    2004-05-01

    This article presents the theoretical calculation of the variation of displacement damage factors as a function of energy and rad equivalent fluence in bipolar junction transistor for various particulate radiation viz ., He, Si, Cl, Ti, Ni, Br, Ag, I, and Au. The calculation is based on the experimental data on gamma-ray induced gain degradation in a commercial space borne BJT (2N3019). The method involves the calculation of gamma-ray dose (rad(Si)) equivalent of effective particle fluence. The linear energy transfer (LET) in silicon for different particle radiation obtained from TRIM calculation has been used for the conversion of gamma-dose into fluence of various particles. The estimation predicts a smooth increase in the displacement damage factor as the mass of the ion increases. Further, the displacement damage factor reaches a maximum at the same value of energy, which corresponds to maximum LET for all heavy ions. The maximum value of damage factor marginally decreases with increasing ion fluence for an ion of given energy. The results are compared with the data available in the literature for proton, deuteron, and helium induced displacement damage.

  1. Investigating the dynamic properties of an MOS-transistor structure

    OpenAIRE

    Likhobabin, N. P.; Politanskii, L. F.; Vatamanyuk, P. P.

    1990-01-01

    The literature provides practically no information on the operation of MOS-transistor switches in the low-temperature range. The purpose of the present work was to study the dynamic parameters in the temperature range from 77 to 400 K. The investigations were carried out on horizontal high-voltage MOS structures having a drift region and a polysilicon gate, which had been fabricated on KDB80 plates.

  2. Amorphous silicon germanium carbide photo sensitive bipolar junction transistor with a base-contact and a continuous tunable high current gain

    Energy Technology Data Exchange (ETDEWEB)

    Bablich, A., E-mail: andreas.bablich@uni-siegen.de [Department of Electrical and Computer Engineering, Institute for Microsystem Technologies, University of Siegen, Hoelderlinstrasse 3, 57076 Siegen (Germany); Merfort, C., E-mail: merfort@imt.e-technik.uni-siegen.de [Department of Electrical and Computer Engineering, Institute for Microsystem Technologies, University of Siegen, Hoelderlinstrasse 3, 57076 Siegen (Germany); Eliasz, J., E-mail: jacek.eliasz@student.uni-siegen.de [Department of Electrical and Computer Engineering, Institute for Microsystem Technologies, University of Siegen, Hoelderlinstrasse 3, 57076 Siegen (Germany); Schäfer-Eberwein, H., E-mail: heiko.schaefer@uni-siegen.de [Department of Electrical and Computer Engineering, Institute of High Frequency and Quantum Electronics, University of Siegen, Hoelderlinstrasse 3, 57076 Siegen (Germany); Haring-Bolivar, P., E-mail: peter.haring@uni-siegen.de [Department of Electrical and Computer Engineering, Institute of High Frequency and Quantum Electronics, University of Siegen, Hoelderlinstrasse 3, 57076 Siegen (Germany); Boehm, M., E-mail: markus.boehm@uni-siegen.de [Department of Electrical and Computer Engineering, Institute for Microsystem Technologies, University of Siegen, Hoelderlinstrasse 3, 57076 Siegen (Germany)

    2014-05-02

    In this paper, the design, fabrication and characterization of an amorphous silicon germanium carbide (a-SiGeC:H) photo sensitive bipolar junction transistor (PS-BJT) with three terminals are presented. Whereas the current gain of similar transistor devices presented in the past (Wu et al., 1984; Hwang et al., 1993; Nascetti and Caputo, 2002; Chang et al., 1985a,b; Wu et al, 1985; Hong et al., 1990) can only be controlled with photo induced charge generation, the n–i–δp–i–n structure developed features a contacted base to provide the opportunity to adjust the current gain optically and electrically, too. Electron microscope-, current-/voltage- and spectral measurements were performed to study the PS-BJT behavior and calculate the electrical and optical current gain. The spectral response maximum of the base–collector diode has a value of 170 mA/W applying a base–collector voltage of − 1 V and is located at 620 nm. The base–emitter diode reaches a sensitivity of 25.7 mA/W at 530 nm with a base-emitter voltage of − 3 V. The good a-Si:H transport properties are validated in a μτ-product of 4.6 × 10{sup −6} cm{sup 2} V s, which is sufficient to reach a continuous base- and photo-tunable current gain of up to − 126 at a base current of I{sub B} = + 10 nA and a collector–emitter voltage of V{sub CE} = − 3 V. The transistor obtains a maximum collector current of − 65.5 μA (V{sub CE} = − 3 V) and + 56.2 μA (V{sub CE} = + 3 V) at 10,000 lx 5300 K white-light illumination. At 3300 lx, the electrical current gain reaches a value of + 100 (V{sub CE} = + 2 V) at I{sub B} = 10 nA. With a negative base current of I{sub B} = − 10 nA the electrical gain can be adjusted between 87 (V{sub CE} = + 2 V) and − 106 (V{sub CE} = -3 V), respectively. When no base charge is applied, the transistor is “off” for V{sub CE} > − 3 V. Reducing the base current increases the electrical current gain. Operating with a voltage V{sub CE} of just ± 2 V

  3. Unipolar and bipolar operation of InAs/InSb nanowire heterostructure field-effect transistors

    Science.gov (United States)

    Nilsson, Henrik A.; Caroff, Philippe; Lind, Erik; Pistol, Mats-Erik; Thelander, Claes; Wernersson, Lars-Erik

    2011-09-01

    We present temperature dependent electrical measurements on n-type InAs/InSb nanowire heterostructure field-effect transistors. The barrier height of the heterostructure junction is determined to be 220 meV, indicating a broken bandgap alignment. A clear asymmetry is observed when applying a bias to either the InAs or the InSb side of the junction. Impact ionization and band-to-band tunneling is more pronounced when the large voltage drop occurs in the narrow bandgap InSb segment. For small negative gate-voltages, the InSb segment can be tuned toward p-type conduction, which induces a strong band-to-band tunneling across the heterostructucture junction.

  4. Characterization of a power bipolar transistor as high-dose dosimeter for 1.9-2.2 MeV electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Fuochi, P.G., E-mail: fuochi@isof.cnr.i [ISOF-CNR Institute, Via P. Gobetti 101, I-40129, Bologna (Italy); Lavalle, M.; Corda, U. [ISOF-CNR Institute, Via P. Gobetti 101, I-40129, Bologna (Italy); Kuntz, F.; Plumeri, S. [Aerial, Parc d' Innovation Rue Laurent Fries F-67400 Illkirch (France); Gombia, E. [IMEM-CNR Institute, Viale delle Scienze 37 A, Loc. Fontanini, 43010 Parma (Italy)

    2010-04-15

    Results of the characterization studies on a power bipolar transistor investigated as a possible radiation dosimeter under laboratory condition using electron beams of energies from 2.2 to 8.6 MeV and gamma rays from a {sup 60}Co source and tested in industrial irradiation plants having high-activity {sup 60}Co gamma-source and high-energy, high-power electron beam have previously been reported. The present paper describes recent studies performed on this type of bipolar transistor irradiated with 1.9 and 2.2 MeV electron beams in the dose range 5-50 kGy. Dose response, post-irradiation heat treatment and stability, effects of temperature during irradiation in the range from -104 to +22 deg. C, dependence on temperature during reading in the range 20-50 deg. C, and the difference in response of the transistors irradiated from the plastic side and the copper side are reported. DLTS measurements performed on the irradiated devices to identify the recombination centres introduced by radiation and their dependence on dose and energy of the electron beam are also reported.

  5. Models for the structure and origin of bipolar nebulae

    International Nuclear Information System (INIS)

    Morris, M.

    1981-01-01

    The appearance of bipolar nebulae-symmetric reflection nebulae centered on evolved, mass-losing stars-can most simply be accounted for in terms of an axisymmetric distribution of outflowing dust in which the dust is concentrated towards an equatorial plane and declines monotonically with latitude above that plane. The symmetrically placed ''horns'' that can be seen radiating out of some bipolar nebulae, notably GL 2688, are a natural consequence of such a dust distribution if, at some latitude, the radial optical depth to starlight falls rapidly below unity. Several models of bipolar nebulae are presented. These structural models for bipolar nebulae lead in turn to an investigation of how such a geometry might arise. Although nonradial pulsation, rotationally forced mass ejection by a single star, and mass loss from a common envelope binary are all considered, the most attractive origin for bipolar nebulae is a binary star system in which the primary is evolving up the red giant branch to the point at which its radius approaches its tidal radius. If this occurs before corotation of the primary with the secondary's orbit can be achieved, then matter from the primary's enveloped can be gravitationally ejected from the system by the secondary, the ejected material being concentrated toward the system's equatorial plane. Numerical models of this phenomenon show that gravitational ejection from an asynchronous binary system easily leads to terminal outflow velocities in the observed range (20--50 km s -1 ), and that the rate of mass loss and the time scale over which the mass ejection takes place are consistent with observations if the particle density in the outer layers of the primary's atmosphere from which the material is extracted is in the range 10 14 --10 15 cm -3 . If this hypothesis is applicable, bipolar nebulae will probably become planetary nebulae, as previously suggested on observational grounds

  6. DC parameter extraction of equivalent circuit model in InGaAsSb heterojunction bipolar transistors including non-ideal effects in the base region

    Science.gov (United States)

    Chang, Yang-Hua; Cheng, Zong-Tai

    2011-07-01

    This paper presents the DC parameter extraction of the equivalent circuit model in an InP-InGaAsSb double heterojunction bipolar transistor (HBT). The non-ideal collector current is modeled by a non-ideal doping distribution in the base region. Then several consequent non-ideal effects, which have always been neglected in typical HBTs, are studied using Medici device simulator. Moreover, the associated DC parameters of VBIC model are extracted accordingly. The equivalent circuit model is in good agreement with the measured data in I C- V CE characteristics.

  7. Two-dimensional analysis of the interface state effect on current gain for a 4H-SiC bipolar junction transistor

    Science.gov (United States)

    Zhang, You-Run; Zhang, Bo; Li, Zhao-Ji; Deng, Xiao-Chuan

    2010-06-01

    This paper studies two-dimensional analysis of the surface state effect on current gain for a 4H-SiC bipolar junction transistor (BJT). Simulation results indicate the mechanism of current gain degradation, which is surface Fermi level pinning leading to a strong downward bending of the energy bands to form the channel of surface electron recombination current. The experimental results are well-matched with the simulation, which is modeled by exponential distributions of the interface state density replacing the single interface state trap. Furthermore, the simulation reveals that the oxide quality of the base emitter junction interface is very important for 4H-SiC BJT performance.

  8. Brain Structural Effects of Psychopharmacological Treatment in Bipolar Disorder

    Science.gov (United States)

    McDonald, Colm

    2015-01-01

    Bipolar disorder is associated with subtle neuroanatomical deficits including lateral ventricular enlargement, grey matter deficits incorporating limbic system structures, and distributed white matter pathophysiology. Substantial heterogeneity has been identified by structural neuroimaging studies to date and differential psychotropic medication use is potentially a substantial contributor to this. This selective review of structural neuroimaging and diffusion tensor imaging studies considers evidence that lithium, mood stabilisers, antipsychotic medication and antidepressant medications are associated with neuroanatomical variation. Most studies are negative and suffer from methodological weaknesses in terms of directly assessing medication effects on neuroanatomy, since they commonly comprise posthoc assessments of medication associations with neuroimaging metrics in small heterogenous patient groups. However the studies which report positive findings tend to form a relatively consistent picture whereby lithium and antiepileptic mood stabiliser use is associated with increased regional grey matter volume, especially in limbic structures. These findings are further supported by the more methodologically robust studies which include large numbers of patients or repeated intra-individual scanning in longitudinal designs. Some similar findings of an apparently ameliorative effect of lithium on white matter microstructure are also emerging. There is less support for an effect of antipsychotic or antidepressant medication on brain structure in bipolar disorder, but these studies are further limited by methodological difficulties. In general the literature to date supports a normalising effect of lithium and mood stabilisers on brain structure in bipolar disorder, which is consistent with the neuroprotective characteristics of these medications identified by preclinical studies. PMID:26412064

  9. Formation of MOS-transistors with isolation of active elements by oxiden porous silicon

    Directory of Open Access Journals (Sweden)

    Novosyadlyi S. P.

    2009-06-01

    Full Text Available The superthin functional layers of MOS-transistors require qualitative isolation of active elements. The new method of formation of epitaksial structures for technology «silicon - on-isolator» is offered on the basis of porous silicon. It will allow to form three kinds of transistorsbipolar, SМОS, DМОS.

  10. Temas de Física para Ingeniería: El transistor de unión

    OpenAIRE

    Beléndez Vázquez, Augusto; Pastor Antón, Carlos; Martín García, Agapito

    1990-01-01

    El transistor de unión bipolar. Tensiones y corrientes en el transistor. El transistor como amplificador. El transistor como conmutador. Transistores unipolares o de efecto de campo. El tiristor. Microelectrónica y circuitos integrados.

  11. High current gain 4H-SiC bipolar junction transistor

    Science.gov (United States)

    Yourun, Zhang; Jinfei, Shi; Ying, Liu; Chengchun, Sun; Fei, Guo; Bo, Zhang

    2016-04-01

    A novel 4H-SiC BJT of high current gain with a suppressing surface traps effect has been proposed. It is effective to improve the current gain due to the lower electrons density in the surface region by extending the emitter metal to overlap the passivation layer on the extrinsic base surface. The electrons trapped in the extrinsic base surface induce the degeneration of SiC BJTs device performance. By modulating the electron recombination rate, the novel structure can increase the current gain to 63.2% compared with conventional ones with the compatible process technology. Optimized sizes are an overlapped metal length of 4 μm, as well as an oxide layer thickness of 50 nm. Project supported by the National Natural Science Foundation of China (Nos. 61306093, 61401075).

  12. Highly stable thin film transistors using multilayer channel structure

    KAUST Repository

    Nayak, Pradipta K.

    2015-03-09

    We report highly stable gate-bias stress performance of thin film transistors (TFTs) using zinc oxide (ZnO)/hafnium oxide (HfO2) multilayer structure as the channel layer. Positive and negative gate-bias stress stability of the TFTs was measured at room temperature and at 60°C. A tremendous improvement in gate-bias stress stability was obtained in case of the TFT with multiple layers of ZnO embedded between HfO2 layers compared to the TFT with a single layer of ZnO as the semiconductor. The ultra-thin HfO2 layers act as passivation layers, which prevent the adsorption of oxygen and water molecules in the ZnO layer and hence significantly improve the gate-bias stress stability of ZnO TFTs.

  13. Broad Beam and Ion Microprobe Studies of Single-Event Upsets in High Speed 0.18micron Silicon Germanium Heterojunction Bipolar Transistors and Circuits

    Science.gov (United States)

    Reed, Robert A.; Marshall, Paul W.; Pickel, Jim; Carts, Martin A.; Irwin, TIm; Niu, Guofu; Cressler, John; Krithivasan, Ramkumar; Fritz, Karl; Riggs, Pam

    2003-01-01

    SiGe based technology is widely recognized for its tremendous potential to impact the high speed microelectronic industry, and therefore the space industry, by monolithic incorporation of low power complementary logic with extremely high speed SiGe Heterojunction Bipolar Transistor (HBT) logic. A variety of studies have examined the ionizing dose, displacement damage and single event characteristics, and are reported. Accessibility to SiGe through an increasing number of manufacturers adds to the importance of understanding its intrinsic radiation characteristics, and in particular the single event effect (SEE) characteristics of the high bandwidth HBT based circuits. IBM is now manufacturing in its 3rd generation of their commercial SiGe processes, and access is currently available to the first two generations (known as and 6HP) through the MOSIS shared mask services with anticipated future release of the latest (7HP) process. The 5 HP process is described and is characterized by a emitter spacing of 0.5 micron and a cutoff frequency ff of 50 GHz, whereas the fully scaled 7HP HBT employs a 0.18 micron emitter and has an fT of 120 GHz. Previous investigations have the examined SEE response of 5 HP HBT circuits through both circuit testing and modeling. Charge collection modeling studies in the 5 H P process have also been conducted, but to date no measurements have been reported of charge collection in any SiGe HBT structures. Nor have circuit models for charge collection been developed in any version other than the 5 HP HBT structure. Our investigation reports the first indications of both charge collection and circuit response in IBM s 7HP-based SiGe process. We compare broad beam heavy ion SEU test results in a fully function Pseudo-Random Number (PRN) sequence generator up to frequencies of 12 Gbps versus effective LET, and also report proton test results in the same circuit. In addition, we examine the charge collection characteristics of individual 7HP HBT

  14. Characterization of ionizing radiation effects in MOS structures by study of bipolar operation; Caracterisation des effets induits par irradiations ionisantes dans des structures MOS a partir de leur fonctionnement en regime bipolaire

    Energy Technology Data Exchange (ETDEWEB)

    Bakhtiar, H. [Univ. Teknologi Malaysia, Dept. of Physics, Johor (Malaysia); Picard, C.; Brisset, C. [CEA Saclay, Lab. d' Electronique et de Technologie de l' Informatique, LETI, 91 - Gif-sur-Yvette (France); Bakhtiar, H.; Hoffmann, A.; Charles, J.P. [Metz Univ., LICM-CLOES-Supelec, 57 (France)

    1999-07-01

    This work presents an original method to characterize radiation effects of micronic transistors. The characterization includes a study of the transistor substrate-drain junction and current gain variation of the bipolar transistor (drain-substrate-source as emitter-base-collector) for different gate voltages. (author000.

  15. In(0.52)Al(0.48)/In(0.53)Ga(0.47)As heterojunction bipolar transistor on GaAs by molecular beam epitaxy

    Science.gov (United States)

    Won, T.; Agarwala, S.; Morkoc, H.

    1988-12-01

    The successful operation of In(0.52)Al(0.48)As/In(0.53)Ga(0.47)As NpN double heterojunction bipolar transistors grown on GaAs substrates is reported. A 10-period AlAs/In(0.52)Al(0.48)As (20 A/20 A) strained-layer superlattice was repeated twice with intervening undoped In(0.52)Al(0.48)As layers to suppress the propagation of threading dislocations to the surface. The typical common emitter gain in 50 x 50 micron-squared emitter area devices was 50, with a maximum of 63, at a collector current density of 2000 A/sq cm.

  16. Enhanced Miller plateau characteristics of a 4H-SiC insulated-gate bipolar transistor in the presence of interface traps

    Science.gov (United States)

    Navarro, Dondee; Tone, Akihiro; Kikuchihara, Hideyuki; Morikawa, Yoji; Miura-Mattausch, Mitiko

    2017-04-01

    Miller plateau characteristics of a 4H-SiC insulated-gate bipolar transistor (IGBT) is investigated during a gate voltage turn-on under the presence of interface carrier traps at the MOSFET gate oxide. The plateau, which is observed in the device gate-emitter voltage, increased with respect to both height and length. The plateau height is mainly determined by the density increase of trap states, which also causes slow charging of the gate capacitance in the overlap region that results in a longer plateau length. The shallow trap states contribute mainly to the plateau increase. It is observed that the switching loss at turn-on can increase by more than 60% due mainly to the carrier traps at the shallow trap states.

  17. Study About High Influence Doping to Base Resistance and Bandgap Narrowing at Si/Si1-xGex/Si Heterojunction Bipolar Transistor

    Directory of Open Access Journals (Sweden)

    Achmad Fadhol

    2010-10-01

    Full Text Available Heterojunction is a link formed bedween two semiconductor materials and differend bandgap which has thinness under 50nm and grow the mixture of plate SiGe as bases. The link is an abrupt link or graded one. In this research learnt formulation of doping concentration influence to basis resistance and bandgap narrowing through Si/Si1-xGex/Si Heterojunction Bipolar Transistor with abrupt emitter-basis link, besides taking care to mobility and basis wide to basis resistance, it is also influence of mole fraction to bandgap power. From the result shows that doping concentration addition of NB=5.1018 cm-3 to NB=5.1020 cm-3 in basis can decrease resistance basis value about 3.6%, increase bandgap narrowing about 0.126, and increase collector current density for about 1.36 times to Ge 24%.

  18. Effects of base doping and carrier lifetime on differential current gain and temperature coefficient of 4H-SiC power bipolar junction transistors

    Science.gov (United States)

    Niu, X.; Fardi, H.

    2012-04-01

    4H-SiC NPN bipolar junction transistor (BJT) is studied systematically by performing two-dimensional numerical simulations. Several design issues are discussed. Depending on the doping concentration of the base and the carrier lifetimes, both positive and negative temperature coefficients in the common emitter current gain could exist in 4H-SiC NPN BJTs with aluminium-doped base. The temperature coefficients of the current gain at different base doping concentrations and different carrier lifetimes have been determined. A high base doping concentration can reduce the requirement for the carrier lifetime in order to obtain negative temperature coefficient in current gain. Device simulations are performed to evaluate the carrier lifetimes by fitting the measured output IC -VCE curves. An excellent fitting is obtained and the base electron lifetime and the emitter hole lifetime are extracted to be about 22 and 5.7 ns, respectively.

  19. Genetic structure of personality factors and bipolar disorder in families segregating bipolar disorder.

    Science.gov (United States)

    Hare, Elizabeth; Contreras, Javier; Raventos, Henriette; Flores, Deborah; Jerez, Alvaro; Nicolini, Humberto; Ontiveros, Alfonso; Almasy, Laura; Escamilla, Michael

    2012-02-01

    Bipolar disorder (BPD) has been associated with variations in personality dimensions, but the nature of this relationship has been unclear. In this study, the heritabilities of BPD and the Big Five personality factors and the genetic correlations between BPD and personality factors are reported. The participants in this study were 1073 individuals from 172 families of Mexican or Central American ancestry. Heritabilities and genetic correlations were calculated under a polygenic model using the maximum-likelihood method of obtaining variance components implemented in the SOLAR software package. Heritabilities of 0.49, 0.43, and 0.43 were found for the narrowest phenotype (schizoaffective bipolar and bipolar I), the intermediate phenotype (schizoaffective bipolar, bipolar I, and bipolar II), and the broadest phenotype (schizoaffective bipolar, bipolar I, bipolar II, and recurrent depression), respectively. For the Big Five personality factors, heritabilities were 0.25 for agreeableness, 0.24 for conscientiousness, 0.24 for extraversion, 0.23 for neuroticism, and 0.32 for openness to experience. For the narrowest phenotype, a significant negative correlation (-0.32) with extraversion was found. For the broadest phenotype, negative correlations were found for agreeableness (-0.35), conscientiousness (-0.39), and extraversion (-0.44). A positive correlation (0.37) was found with neuroticism. It is not possible to determine whether aspects of personality are factors in the development of bipolar disorder or vice versa. The short form of the NEO does not provide the ability to examine in detail which facets of extraversion are most closely related to bipolar disorder or to compare our results with studies that have used the long version of the scale. This study establishes a partial genetic basis for the Big Five personality factors in this set of families, while the environmental variances demonstrate that non-genetic factors are also important in their influence on

  20. N p n bipolar-junction-transistor detector with integrated p n p biasing transistor—feasibility study, design and first experimental results

    Science.gov (United States)

    Verzellesi, Giovanni; Bergamini, Davide; Dalla Betta, Gian-Franco; Piemonte, Claudio; Boscardin, Maurizio; Bosisio, Luciano; Bettarini, Stefano; Batignani, Giovanni

    2006-02-01

    We propose a novel n-p-n BJT radiation detector on high-resistivity silicon with integrated p-n-p transistor providing the quiescent base current of the detector. The dc operational limits of the proposed detector are analysed by means of numerical device simulations, pointing out that, by properly distancing the base of the p-n-p transistor from the emitter of the n-p-n detector, the latch-up of the parasitic thyristor embedded within the detector-plus-biasing-transistor structure takes place at relatively high current levels, where detector operation should anyway be avoided in order to prevent the associated current-gain loss. Numerical simulations provides insight about the bias dependence of charge-collection waveforms, indicating that minimization of the collecting time requires the detector quiescent current to be adjusted at the highest value still allowing high-injection effects to be avoided. A small-signal equivalent circuit of the proposed structure is also derived, allowing the impact of p-n-p biasing transistor and load resistance on the charge-collecting time constant to be evaluated. First experimental results show that fabricated structures are immune from the latch-up of the parasitic thyristor throughout their high-current-gain operating region and feature a minimum charge-collecting time constant of 35 µs, as tested by pulsed laser illumination.

  1. Gate-Controlled WSe2Transistors Using a Buried Triple-Gate Structure.

    Science.gov (United States)

    Müller, M R; Salazar, R; Fathipour, S; Xu, H; Kallis, K; Künzelmann, U; Seabaugh, A; Appenzeller, J; Knoch, J

    2016-12-01

    In the present paper, we show tungsten diselenide (WSe 2 ) devices that can be tuned to operate as n-type and p-type field-effect transistors (FETs) as well as band-to-band tunnel transistors on the same flake. Source, channel, and drain areas of the WSe 2 flake are adjusted, using buried triple-gate substrates with three independently controllable gates. The device characteristics found in the tunnel transistor configuration are determined by the particular geometry of the buried triple-gate structure, consistent with a simple estimation of the expected off-state behavior.

  2. Bipolar mixed states: an international society for bipolar disorders task force report of symptom structure, course of illness, and diagnosis.

    Science.gov (United States)

    Swann, Alan C; Lafer, Beny; Perugi, Giulio; Frye, Mark A; Bauer, Michael; Bahk, Won-Myong; Scott, Jan; Ha, Kyooseob; Suppes, Trisha

    2013-01-01

    Episodes of bipolar disorder are defined as depressive or manic, but depressive and manic symptoms can combine in the same episode. Coexistence or rapid alternation of depressive and manic symptoms in the same episode may indicate a more severe form of bipolar disorder and may pose diagnostic and treatment challenges. However, definitions of mixed states, especially those with prominent depression, are not well established. The authors performed literature searches for bipolar disorder, multivariate analyses, and the appearance of the terms "mixed" in any field; references selected from the articles found after the search were combined after a series of conferences among the authors. The authors reviewed the evolution of the concept of mixed states and examined the symptom structure of mixed states studied as predominantly manic, predominantly depressive, and across both manic and depressive episodes, showing essentially parallel structures of mixed states based on manic or depressive episodes. The authors analyzed the relationships between mixed states and a severely recurrent course of illness in bipolar disorder, with early onset and increased co-occurring anxiety-, stress-, and substance-related disorders, and they used this information to derive proposed diagnostic criteria for research or clinical use. The definitions and properties of mixed states have generated controversy, but the stability of their characteristics over a range of clinical definitions and diagnostic methods shows that the concept of mixed states is robust. Distinct characteristics related to the course of illness emerge at relatively modest opposite polarity symptom levels in depressive or manic episodes.

  3. On the Bipolar DC Flow Field-Effect-Transistor for Multifunctional Sample Handing in Microfluidics: A Theoretical Analysis under the Debye–Huckel Limit

    Directory of Open Access Journals (Sweden)

    Weiyu Liu

    2018-02-01

    Full Text Available We present herein a novel method of bipolar field-effect control on DC electroosmosis (DCEO from a physical point of view, in the context of an intelligent and robust operation tool for stratified laminar streams in microscale systems. In this unique design of the DC flow field-effect-transistor (DC-FFET, a pair of face-to-face external gate terminals are imposed with opposite gate-voltage polarities. Diffuse-charge dynamics induces heteropolar Debye screening charge within the diffuse double layer adjacent to the face-to-face oppositely-polarized gates, respectively. A background electric field is applied across the source-drain terminal and forces the face-to-face counterionic charge of reversed polarities into induced-charge electroosmotic (ICEO vortex flow in the lateral direction. The chaotic turbulence of the transverse ICEO whirlpool interacts actively with the conventional plug flow of DCEO, giving rise to twisted streamlines for simultaneous DCEO pumping and ICEO mixing of fluid samples along the channel length direction. A mathematical model in thin-layer approximation and the low-voltage limit is subsequently established to test the feasibility of the bipolar DC-FFET configuration in electrokinetic manipulation of fluids at the micrometer dimension. According to our simulation analysis, an integrated device design with two sets of side-by-side, but upside-down gate electrode pair exhibits outstanding performance in electroconvective pumping and mixing even without any externally-applied pressure difference. Moreover, a paradigm of a microdevice for fully electrokinetics-driven analyte treatment is established with an array of reversed bipolar gate-terminal pairs arranged on top of the dielectric membrane along the channel length direction, from which we can obtain almost a perfect liquid mixture by using a smaller magnitude of gate voltages for causing less detrimental effects at a small Dukhin number. Sustained by theoretical

  4. Diode, transistor & fet circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Diode, Transistor and FET Circuits Manual is a handbook of circuits based on discrete semiconductor components such as diodes, transistors, and FETS. The book also includes diagrams and practical circuits. The book describes basic and special diode characteristics, heat wave-rectifier circuits, transformers, filter capacitors, and rectifier ratings. The text also presents practical applications of associated devices, for example, zeners, varicaps, photodiodes, or LEDs, as well as it describes bipolar transistor characteristics. The transistor can be used in three basic amplifier configuration

  5. Contribution to the study of fluctuations in transistors (bipolar and junction field effect types); Contribution a l'etude des fluctuations dans les transistors (bipolaires et a effet champ a jonctions)

    Energy Technology Data Exchange (ETDEWEB)

    Borel, J. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1970-07-01

    A brief review of the basic theory of fluctuations in semiconductors is given: shot, thermal low frequency noise. A measuring set has been built to draw noise spectrums (current or voltage). Noise parameters of bipolar transistors are given, mainly noise voltage. Noise current, noise factor and correlation between noise sources are also calculated. Measurements of noise parameters fit well with theory for various devices made in different technologies: alloyed, mesa, planar. Then we give results of the calculation of noise parameters in a FET starting from a simplified model of the device. Low frequency noise is taken into account. Measurements of the parameters and of the spectrum agree fairly well with the theory. Studies of low frequency noise versus temperature give the density and energy of traps located in the space charge layers and an idea of the impurity encountered in these space charge layers. [French] On rappelle les notions de base de la theorie des fluctuations dans les semiconducteurs: bruit de grenaille, bruit thermique, bruit basse frequence. Un appareillage mis au point pour tracer un spectre de bruit est decrit. On presente ensuite le calcul des parametres de bruit d'un transistor bipolaire en insistant plus particulierement sur la tension de bruit ramenee a l'entree de l'element. Le courant de bruit, le facteur de bruit et la correlation entre les sources de bruit sont calcules. La mesure des parametres de bruit est faite sur divers elements realises dans diverses technologies: alliee, mesa et plane. Les mesures confirment tres bien la theorie. On presente ensuite le calcul des parametres de bruit d'un transistor a effet de champ en definissant un schema equivalent simple de l'element. Le calcul theorique des fluctuations basse frequence est aussi fait. La mesure du spectre de bruit confirme tres bien les calculs theoriques. L'etude du bruit basse frequence en fonction de la temperature permet de remonter a la

  6. Multiple facets of tightly coupled transducer-transistor structures.

    Science.gov (United States)

    Heidari, Hadi; Dahiya, Ravinder

    2015-12-04

    The ever increasing demand for data processing requires different paradigms for electronics. Excellent performance capabilities such as low power and high speed in electronics can be attained through several factors including using functional materials, which sometimes acquire superior electronic properties. The transduction-based transistor switching mechanism is one such possibility, which exploits the change in electrical properties of the transducer as a function of a mechanically induced deformation. Originally developed for deformation sensors, the technique is now moving to the centre stage of the electronic industry as the basis for new transistor concepts to circumvent the gate voltage bottleneck in transistor miniaturization. In issue 37 of Nanotechnology, Chang et al show the piezoelectronic transistor (PET), which uses a fast, low-power mechanical transduction mechanism to propagate an input gate voltage signal into an output resistance modulation. The findings by Chang et al will spur further research into piezoelectric scaling, and the PET fabrication techniques needed to advance this type of device in the future.

  7. Multiple facets of tightly coupled transducer-transistor structures

    Science.gov (United States)

    Heidari, Hadi; Dahiya, Ravinder

    2015-12-01

    The ever increasing demand for data processing requires different paradigms for electronics. Excellent performance capabilities such as low power and high speed in electronics can be attained through several factors including using functional materials, which sometimes acquire superior electronic properties. The transduction-based transistor switching mechanism is one such possibility, which exploits the change in electrical properties of the transducer as a function of a mechanically induced deformation. Originally developed for deformation sensors, the technique is now moving to the centre stage of the electronic industry as the basis for new transistor concepts to circumvent the gate voltage bottleneck in transistor miniaturization. In issue 37 of Nanotechnology, Chang et al show the piezoelectronic transistor (PET), which uses a fast, low-power mechanical transduction mechanism to propagate an input gate voltage signal into an output resistance modulation. The findings by Chang et al will spur further research into piezoelectric scaling, and the PET fabrication techniques needed to advance this type of device in the future.

  8. Estudio teórico y práctico del régimen de avalancha en los transistores bipolares

    Directory of Open Access Journals (Sweden)

    Yunior Ávila Vázquez

    2011-09-01

    Full Text Available Normal 0 21 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Se realiza un estudio teórico de la zona de ruptura por avalancha de los Transistores Bipolares y la caracterización de los mismos en dichas condiciones extremas de trabajo, para obtener los datos necesarios y de esta manera un criterio de selección, que permitan utilizarlos en un generador de pulsos, basado en la topología del banco de Marx y lograr un funcionamiento adecuado de este, aunque estos transistores no estén diseñados para trabajar en avalancha. Normal 0 21 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;}

  9. Vertical Hole Transport and Carrier Localization in InAs /InAs1 -xSbx Type-II Superlattice Heterojunction Bipolar Transistors

    Science.gov (United States)

    Olson, B. V.; Klem, J. F.; Kadlec, E. A.; Kim, J. K.; Goldflam, M. D.; Hawkins, S. D.; Tauke-Pedretti, A.; Coon, W. T.; Fortune, T. R.; Shaner, E. A.; Flatté, M. E.

    2017-02-01

    Heterojunction bipolar transistors are used to measure vertical hole transport in narrow-band-gap InAs /InAs1 -xSbx type-II superlattices (T2SLs). Vertical hole mobilities (μh) are reported and found to decrease rapidly from 360 cm2/V s at 120 K to approximately 2 cm2/V s at 30 K, providing evidence that holes are confined to localized states near the T2SL valence-miniband edge at low temperatures. Four distinct transport regimes are identified: (1) pure miniband transport, (2) miniband transport degraded by temporary capture of holes in localized states, (3) hopping transport between localized states in a mobility edge, and (4) hopping transport through defect states near the T2SL valence-miniband edge. Region (2) is found to have a thermal activation energy of ɛ2=36 meV corresponding to the energy range of a mobility edge. Region (3) is found to have a thermal activation energy of ɛ3=16 meV corresponding to the hopping transport activation energy. This description of vertical hole transport is analogous to electronic transport observed in disordered amorphous semiconductors displaying Anderson localization. For the T2SL, we postulate that localized states are created by disorder in the group-V alloy of the InAs1 -xSbx hole well causing fluctuations in the T2SL valence-band energy.

  10. Standard Test Method for Use of 2N2222A Silicon Bipolar Transistors as Neutron Spectrum Sensors and Displacement Damage Monitors

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers the use of 2N2222A silicon bipolar transistors as dosimetry sensors in the determination of neutron energy spectra, and as silicon 1-MeV(Si) equivalent displacement damage fluence monitors. 1.2 The neutron displacement damage is especially valuable as a neutron spectrum sensor in the range 0.1 to 2.0 MeV when fission foils are not available. It has been applied in the fluence range between 2 × 10 12 n/cm2 and 1 × 1014 n/cm2 and should be useful up to 1015 n/cm2. This test method details the steps for the acquisition and use of silicon 1-MeV equivalent fluence information (in a manner similar to the use of activation foil data) for the determination of neutron spectra. 1.3 In addition, this sensor can provide important confirmation of neutron spectra determined with other sensors, and yields a direct measurement of the silicon 1-MeV fluence by the transfer technique. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in ...

  11. Enhancement of minority carrier injection in ambipolar carbon nanotube transistors using double-gate structures

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bongjun; Liang, Kelly; Dodabalapur, Ananth, E-mail: ananth.dodabalapur@engr.utexas.edu [Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States); Geier, Michael L.; Hersam, Mark C. [Department of Materials Science and Engineering and Department of Chemistry, Northwestern University, Evanston, Illinois 60208 (United States)

    2016-07-11

    We show that double-gate ambipolar thin-film transistors can be operated to enhance minority carrier injection. The two gate potentials need to be significantly different for enhanced injection to be observed. This enhancement is highly beneficial in devices such as light-emitting transistors where balanced electron and hole injections lead to optimal performance. With ambipolar single-walled carbon nanotube semiconductors, we demonstrate that higher ambipolar currents are attained at lower source-drain voltages, which is desired for portable electronic applications, by employing double-gate structures. In addition, when the two gates are held at the same potential, the expected advantages of the double-gate transistors such as enhanced on-current are also observed.

  12. Generation of short electrical pulses based on bipolar transistorsny

    Directory of Open Access Journals (Sweden)

    M. Gerding

    2004-01-01

    Full Text Available A system for the generation of short electrical pulses based on the minority carrier charge storage and the step recovery effect of bipolar transistors is presented. Electrical pulses of about 90 ps up to 800 ps duration are generated with a maximum amplitude of approximately 7V at 50Ω. The bipolar transistor is driven into saturation and the base-collector and base-emitter junctions become forward biased. The resulting fast switch-off edge of the transistor’s output signal is the basis for the pulse generation. The fast switching of the transistor occurs as a result of the minority carriers that have been injected and stored across the base-collector junction under forward bias conditions. If the saturated transistor is suddenly reverse biased the pn-junction will appear as a low impedance until the stored charge is depleted. Then the impedance will suddenly increase to its normal high value and the flow of current through the junction will turn to zero, abruptly. A differentiation of the output signal of the transistor results in two short pulses with opposite polarities. The differentiating circuit is implemented by a transmission line network, which mainly acts as a high pass filter. Both the transistor technology (pnp or npn and the phase of the transfer function of the differentating circuit influence the polarity of the output pulses. The pulse duration depends on the transistor parameters as well as on the transfer function of the pulse shaping network. This way of generating short electrical pulses is a new alternative for conventional comb generators based on steprecovery diodes (SRD. Due to the three-terminal structure of the transistor the isolation problem between the input and the output signal of the transistor network is drastically simplified. Furthermore the transistor is an active element in contrast to a SRD, so that its current gain can be used to minimize the power of the driving signal.

  13. Comparison of the leading-edge timing walk in pulsed TOF laser range finding with avalanche bipolar junction transistor (BJT) and metal-oxide-semiconductor (MOS) switch based laser diode drivers.

    Science.gov (United States)

    Hintikka, Mikko; Hallman, Lauri; Kostamovaara, Juha

    2017-12-01

    Timing walk error in pulsed time-of-flight based laser range finding was studied using two different types of laser diode drivers. The study compares avalanche bipolar junction transistor (BJT) and metal-oxide-semiconductor field-effect transistor switch based laser pulse drivers, both producing 1.35 ns current pulse length (full width at half maximum), and investigates how the slowly rising part of the current pulse of the avalanche BJT based driver affects the leading edge timing walk. The walk error was measured to be very similar with both drivers within an input signal dynamic range of 1:10 000 (receiver bandwidth of 700 MHz) but increased rapidly with the avalanche BJT based driver at higher values of dynamic range. The slowly rising part does not exist in the current pulse produced by the metal-oxide-semiconductor (MOS) based laser driver, and thus the MOS based driver can be utilized in a wider dynamic range.

  14. Factor analysis of regional brain activation in bipolar and healthy individuals reveals a consistent modular structure.

    Science.gov (United States)

    Fleck, David E; Welge, Jeffrey A; Eliassen, James C; Adler, Caleb M; DelBello, Melissa P; Strakowski, Stephen M

    2018-02-27

    The neurophysiological substrates of cognition and emotion, as seen with fMRI, are generally explained using modular structures. The present study was designed to probe the modular structure of cognitive-emotional processing in bipolar and healthy individuals using factor analysis and compare the results with current conceptions of the neurophysiology of bipolar disorder. Exploratory factor analysis was used to assess patterns of covariation among brain regions-of-interest activated during the Continuous Performance Task with Emotional and Neutral Distractors in healthy and bipolar individuals without a priori constraints on the number or composition of latent factors. Results indicated a common cognitive-emotional network consisting of prefrontal, medial temporal, limbic, parietal, anterior cingulate and posterior cingulate modules. However, reduced brain activation to emotional stimuli in the frontal, medial temporal and limbic modules was apparent in the bipolar relative to the healthy group, potentially accounting for emotional dysregulation in bipolar disorder. This study is limited by a relatively small sample size recruited at a single site. The results have yet to be validated on a larger independent sample. Although the modular structure of cognitive-emotional processing is similar in bipolar and healthy individuals, activation in response to emotional/neutral cues varies. These findings are not only consistent with recent conceptions of mood regulation in bipolar disorder, but also suggest that regional activation can be considered within tighter modular structures without compromising data interpretation. This demonstration may serve as a template for data reduction in future region-of-interest analyses to increase statistical power. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Theory of localized bipolar wave-structures and nonthermal particle distributions in the auroral ionosphere

    Directory of Open Access Journals (Sweden)

    M. V. Goldman

    1999-01-01

    Full Text Available Bipolar wave structures and nonthermal particle distributions measured by the FAST satellite in regions of downward current are interpreted in terms of the nonlinear evolution of a two-stream instability. The instability results in holes, both in the electron distribution in phase space and in the electron density in real space. The wave potential energy, which traps the electrons, has a single minimum, and the associated electric field is bipolar. The early bipolar structures are coherent over hundreds of Debye lengths in the direction perpendicular to the magnetic field. After thousands of plasma periods the perpendicular coherence is lost, the structures break up, and electrostatic whistlers begin to dominate. Simulations and preliminary analysis of this breakup and emission process are presented.

  16. Brain structural changes in schizoaffective disorder compared to schizophrenia and bipolar disorder.

    Science.gov (United States)

    Amann, B L; Canales-Rodríguez, E J; Madre, M; Radua, J; Monte, G; Alonso-Lana, S; Landin-Romero, R; Moreno-Alcázar, A; Bonnin, C M; Sarró, S; Ortiz-Gil, J; Gomar, J J; Moro, N; Fernandez-Corcuera, P; Goikolea, J M; Blanch, J; Salvador, R; Vieta, E; McKenna, P J; Pomarol-Clotet, E

    2016-01-01

    Brain structural changes in schizoaffective disorder, and how far they resemble those seen in schizophrenia and bipolar disorder, have only been studied to a limited extent. Forty-five patients meeting DSM-IV and RDC criteria for schizoaffective disorder, groups of patients with 45 matched schizophrenia and bipolar disorder, and 45 matched healthy controls were examined using voxel-based morphometry (VBM). Analyses comparing each patient group with the healthy control subjects found that the patients with schizoaffective disorder and the patients with schizophrenia showed widespread and overlapping areas of significant volume reduction, but the patients with bipolar disorder did not. A subsequent analysis compared the combined group of patients with the controls followed by extraction of clusters. In regions where the patients differed significantly from the controls, no significant differences in mean volume between patients with schizoaffective disorder and patients with schizophrenia in any of five regions of volume reduction were found, but mean volumes in the patients with bipolar disorder were significantly smaller in three of five. The findings provide evidence that, in terms of structural gray matter brain abnormality, schizoaffective disorder resembles schizophrenia more than bipolar disorder. © 2015 The Authors. Acta Psychiatrica Scandinavica Published by John Wiley & Sons Ltd.

  17. RESEARCH AND THE ANALYSIS OF CHANGE OF PARAMETERS IN THE CHANNEL OF AVERAGE HIGH-VOLTAGE BIPOLAR STATIC INDUCTION TRANSISTOR

    Directory of Open Access Journals (Sweden)

    P. R. Zakharova

    2013-01-01

    Full Text Available When developing a technology of power device’s structure generation the breakdown voltage and the resistance of silicon substrate are constitutive parameters. Modern generation methods allow to create a structure based on fragile materials which behavior directly depends on the breakdown voltage and the resistance of chosen materials in the depth of structure. In this paper the work on determination the crystal’s channel resistance dependence of its structural parameters for the average high-voltage BSIT is done.

  18. Personality in proportion : A bipolar proportional scale for personality assessments and its consequences for trait structure

    NARCIS (Netherlands)

    Hofstee, W.K.B.; Ten Berge, J.M.F.

    2004-01-01

    Trait structures resulting from personality assessments on Likert scales are affected by the additive and multiplicative transformations implied in interval scaling and correlational analysis. The effect comes into view on selecting a plausible alternative scale. To this end, we propose a bipolar

  19. Brain structure-function associations in multi-generational families genetically enriched for bipolar disorder.

    Science.gov (United States)

    Fears, Scott C; Schür, Remmelt; Sjouwerman, Rachel; Service, Susan K; Araya, Carmen; Araya, Xinia; Bejarano, Julio; Knowles, Emma; Gomez-Makhinson, Juliana; Lopez, Maria C; Aldana, Ileana; Teshiba, Terri M; Abaryan, Zvart; Al-Sharif, Noor B; Navarro, Linda; Tishler, Todd A; Altshuler, Lori; Bartzokis, George; Escobar, Javier I; Glahn, David C; Thompson, Paul M; Lopez-Jaramillo, Carlos; Macaya, Gabriel; Molina, Julio; Reus, Victor I; Sabatti, Chiara; Cantor, Rita M; Freimer, Nelson B; Bearden, Carrie E

    2015-07-01

    Recent theories regarding the pathophysiology of bipolar disorder suggest contributions of both neurodevelopmental and neurodegenerative processes. While structural neuroimaging studies indicate disease-associated neuroanatomical alterations, the behavioural correlates of these alterations have not been well characterized. Here, we investigated multi-generational families genetically enriched for bipolar disorder to: (i) characterize neurobehavioural correlates of neuroanatomical measures implicated in the pathophysiology of bipolar disorder; (ii) identify brain-behaviour associations that differ between diagnostic groups; (iii) identify neurocognitive traits that show evidence of accelerated ageing specifically in subjects with bipolar disorder; and (iv) identify brain-behaviour correlations that differ across the age span. Structural neuroimages and multi-dimensional assessments of temperament and neurocognition were acquired from 527 (153 bipolar disorder and 374 non-bipolar disorder) adults aged 18-87 years in 26 families with heavy genetic loading for bipolar disorder. We used linear regression models to identify significant brain-behaviour associations and test whether brain-behaviour relationships differed: (i) between diagnostic groups; and (ii) as a function of age. We found that total cortical and ventricular volume had the greatest number of significant behavioural associations, and included correlations with measures from multiple cognitive domains, particularly declarative and working memory and executive function. Cortical thickness measures, in contrast, showed more specific associations with declarative memory, letter fluency and processing speed tasks. While the majority of brain-behaviour relationships were similar across diagnostic groups, increased cortical thickness in ventrolateral prefrontal and parietal cortical regions was associated with better declarative memory only in bipolar disorder subjects, and not in non-bipolar disorder family

  20. Evolution of the MOS transistor - From conception to VLSI

    International Nuclear Information System (INIS)

    Sah, C.T.

    1988-01-01

    Historical developments of the metal-oxide-semiconductor field-effect-transistor (MOSFET) during the last sixty years are reviewed, from the 1928 patent disclosures of the field-effect conductivity modulation concept and the semiconductor triodes structures proposed by Lilienfeld to the 1947 Shockley-originated efforts which led to the laboratory demonstration of the modern silicon MOSFET thirty years later in 1960. A survey is then made of the milestones of the past thirty years leading to the latest submicron silicon logic CMOS (Complementary MOS) and BICMOS (Bipolar-Junction-Transistor CMOS combined) arrays and the three-dimensional and ferroelectric extensions of Dennard's one-transistor dynamic random access memory (DRAM) cell. Status of the submicron lithographic technologies (deep ultra-violet light, X-ray, electron-beam) are summarized. Future trends of memory cell density and logic gate speed are projected. Comparisons of the switching speed of the silicon MOSFET with that of silicon bipolar and GaAs field-effect transistors are reviewed. Use of high-temperature superconducting wires and GaAs-on-Si monolithic semiconductor optical clocks to break the interconnect-wiring delay barrier is discussed. Further needs in basic research and mathematical modeling on the failure mechanisms in submicron silicon transistors at high electric fields (hot electron effects) and in interconnection conductors at high current densities and low as well as high electric fields (electromigration) are indicated

  1. Si/Ge hetero-structure nanotube tunnel field effect transistor

    Science.gov (United States)

    Hanna, A. N.; Hussain, M. M.

    2015-01-01

    We discuss the physics of conventional channel material (silicon/germanium hetero-structure) based transistor topology mainly core/shell (inner/outer) gated nanotube vs. gate-all-around nanowire architecture for tunnel field effect transistor application. We show that nanotube topology can result in higher performance through higher normalized current when compared to nanowire architecture at Vdd = 1 V due to the availability of larger tunneling cross section and lower Shockley-Reed-Hall recombination. Both architectures are able to achieve sub 60 mV/dec performance for more than five orders of magnitude of drain current. This enables the nanotube configuration achieving performance same as the nanowire architecture even when Vdd is scaled down to 0.5 V.

  2. Si/Ge hetero-structure nanotube tunnel field effect transistor

    KAUST Repository

    Hanna, A. N.

    2015-01-07

    We discuss the physics of conventional channel material (silicon/germanium hetero-structure) based transistor topology mainly core/shell (inner/outer) gated nanotube vs. gate-all-around nanowire architecture for tunnel field effect transistor application. We show that nanotube topology can result in higher performance through higher normalized current when compared to nanowire architecture at Vdd-=-1-V due to the availability of larger tunneling cross section and lower Shockley-Reed-Hall recombination. Both architectures are able to achieve sub 60-mV/dec performance for more than five orders of magnitude of drain current. This enables the nanotube configuration achieving performance same as the nanowire architecture even when Vdd is scaled down to 0.5-V.

  3. Method of making self-aligned lightly-doped-drain structure for MOS transistors

    Science.gov (United States)

    Weiner, Kurt H.; Carey, Paul G.

    2001-01-01

    A process for fabricating lightly-doped-drains (LDD) for short-channel metal oxide semiconductor (MOS) transistors. The process utilizes a pulsed laser process to incorporate the dopants, thus eliminating the prior oxide deposition and etching steps. During the process, the silicon in the source/drain region is melted by the laser energy. Impurities from the gas phase diffuse into the molten silicon to appropriately dope the source/drain regions. By controlling the energy of the laser, a lightly-doped-drain can be formed in one processing step. This is accomplished by first using a single high energy laser pulse to melt the silicon to a significant depth and thus the amount of dopants incorporated into the silicon is small. Furthermore, the dopants incorporated during this step diffuse to the edge of the MOS transistor gate structure. Next, many low energy laser pulses are used to heavily dope the source/drain silicon only in a very shallow region. Because of two-dimensional heat transfer at the MOS transistor gate edge, the low energy pulses are inset from the region initially doped by the high energy pulse. By computer control of the laser energy, the single high energy laser pulse and the subsequent low energy laser pulses are carried out in a single operational step to produce a self-aligned lightly-doped-drain-structure.

  4. A High-Precision Adaptive Thermal Network Model for Monitoring of Temperature Variations in Insulated Gate Bipolar Transistor (IGBT Modules

    Directory of Open Access Journals (Sweden)

    Ning An

    2018-03-01

    Full Text Available This paper proposes a novel method for optimizing the Cauer-type thermal network model considering both the temperature influence on the extraction of parameters and the errors caused by the physical structure. In terms of prediction of the transient junction temperature and the steady-state junction temperature, the conventional Cauer-type parameters are modified, and the general method for estimating junction temperature is studied by using the adaptive thermal network model. The results show that junction temperature estimated by our adaptive Cauer-type thermal network model is more accurate than that of the conventional model.

  5. Investigation of Impact of the Gate Circuitry on IGBT Transistor Dynamic Parameters

    Directory of Open Access Journals (Sweden)

    Vytautas Bleizgys

    2011-03-01

    Full Text Available The impact of Insulated Gate Bipolar Transistor driver circuit parameters on the rise and fall time of the collector current and voltage collector-emitter was investigated. The influence of transistor driver circuit parameters on heating of Insulated Gate Bipolar Transistors was investigated as well.Article in Lithuanian

  6. Brain network analysis reveals affected connectome structure in bipolar I disorder.

    Science.gov (United States)

    Collin, Guusje; van den Heuvel, Martijn P; Abramovic, Lucija; Vreeker, Annabel; de Reus, Marcel A; van Haren, Neeltje E M; Boks, Marco P M; Ophoff, Roel A; Kahn, René S

    2016-01-01

    The notion that healthy brain function emerges from coordinated neural activity constrained by the brain's network of anatomical connections--i.e., the connectome--suggests that alterations in the connectome's wiring pattern may underlie brain disorders. Corroborating this hypothesis, studies in schizophrenia are indicative of altered connectome architecture including reduced communication efficiency, disruptions of central brain hubs, and affected "rich club" organization. Whether similar deficits are present in bipolar disorder is currently unknown. This study examines structural connectome topology in 216 bipolar I disorder patients as compared to 144 healthy controls, focusing in particular on central regions (i.e., brain hubs) and connections (i.e., rich club connections, interhemispheric connections) of the brain's network. We find that bipolar I disorder patients exhibit reduced global efficiency (-4.4%, P =0.002) and that this deficit relates (r = 0.56, P 0.1). These findings highlight a role for aberrant brain network architecture in bipolar I disorder with reduced global efficiency in association with disruptions in interhemispheric connectivity, while the central "rich club" system appears not to be particularly affected. © 2015 Wiley Periodicals, Inc.

  7. Dielectric strength of SiO2 in a CMOS transistor structure

    International Nuclear Information System (INIS)

    Soden, J.M.

    1979-01-01

    The distribution of experimental dielectric strengths of SiO 2 gate dielectric in a CMOS transistor structure is shown to be composed of a primary, statistically-normal distribution of high dielectric strength and a secondary distribution spread through the lower dielectric strength region. The dielectric strength was not significantly affected by high level (1 x 10 6 RADS (Si)) gamma radiation or high temperature (200 0 C) stress. The primary distribution breakdowns occurred at topographical edges, mainly at the gate/field oxide interface, and the secondary distribution breakdowns occurred at random locations in the central region of the gate

  8. POWER, METALLURGICAL AND CHEMICAL MECHANICAL ENGINEERING THERMOELECTRIC EVENTS IN LIGHT-EMITTING BIPOLAR SEMICONDUCTOR STRUCTURES

    Directory of Open Access Journals (Sweden)

    P. A. Magomedova

    2017-01-01

    Full Text Available Objective. The development of light-emitting bipolar semiconductor structures having a low level of parasitic heat release.Methods. A method for converting thermoelectric heat in bipolar semiconductor structures into optical radiation to divert the excess energy into the environment was developed. At the same time, the cooling effect on thermoelectric junctions remains. Instead of an inertial process of conductive or convective heat transfer, practically instantaneous heat removal from electronic components to the environment takes place.Results. As a result, light-emitting bipolar semiconductor structures will allow more powerful devices with greater speed and degree of integration to be created. It is possible to produce transparent LED matrices with a two-way arrangement of transparent solar cells and mirror metal electrodes along the perimeter. When current is applied, the LED matrix on one of the transitions will absorb thermal energy; on other electrodes, it will emit radiation that is completely recovered into electricity by means of transparent solar cells following repeated reflection between the mirror electrodes. The low efficiency of solar cells will be completely compensated for with the multiple passages of photons through these batteries.Conclusion. Light-emitting bipolar semiconductor structures will not only improve the reliability of electronic components in a wide range of performance characteristics, but also improve energy efficiency through the use of optical radiation recovery. Semiconductor thermoelectric devices using optical phenomena in conjunction with the Peltier effect allow a wide range of energy-efficient components of radio electronic equipment to be realised, both for discrete electronics and for microsystem techniques. Systems for obtaining ultra-low temperatures in order to achieve superconductivity are of particular value. 

  9. Relationship between structural abnormalities in the cerebellum and dementia, posttraumatic stress disorder and bipolar disorder

    Directory of Open Access Journals (Sweden)

    Leonardo Baldaçara

    Full Text Available ABSTRACT. New evidence suggests that the cerebellum has structural and functional abnormalities in psychiatric disorders. Objective: In this research, the goal was to measure the volume of the cerebellum and its subregions in individuals with psychiatric disorders and to relate these findings to their symptoms. Methods: Patients with different degrees of cognitive impairment (Epidemiology of the Elderly - UNIFESP and patients with post-traumatic stress disorder (PTSD from population studies were analyzed. Also, patients with bipolar disorder from an outpatient clinic (Center for the Study of Mood and Anxiety Disorders, Universidade Federal da Bahia were recruited for this study. All subjects underwent a 1.5T structural magnetic resonance scan. Volumetric measures and symptom measurements, by psychometric scales, were performed and compared between patients and controls. Results: The cerebellum volume was reduced in patients with cognitive impairment without dementia and with dementia, in patients with PTSD, and in patients with bipolar disorder compared to controls. In dementia and PTSD, the left cerebellar hemisphere and vermis volume were reduced. In bipolar disorder, volumes of both hemispheres and the vermis were reduced. In the first two studies, these cerebellar volumetric reductions correlated with symptoms of the disease. Conclusion: The exact nature of cerebellar involvement in mental processes is still not fully understood. However, abnormalities in cerebellar structure and its functions have been reported in some of these diseases. Future studies with larger samples are needed to clarify these findings and investigate whether they are important for treatment and prognosis.

  10. A Scalable Mextram Model for Advanced Bipolar Circuit Design

    NARCIS (Netherlands)

    Wu, H.C.

    2007-01-01

    In this thesis, a referenced based scaling approach and its parameter extraction for the bipolar transistor model Mextram is proposed. It is mainly based on the physical properties of the Mextram parameters, which scale with the junction temperature and geometry of the bipolar transistor. The

  11. An optically controlled SiC lateral power transistor based on SiC/SiCGe super junction structure

    International Nuclear Information System (INIS)

    Pu Hongbin; Cao Lin; Ren Jie; Chen Zhiming; Nan Yagong

    2010-01-01

    An optically controlled SiC/SiCGe lateral power transistor based on superjunction structure has been proposed, in which n-SiCGe/p-SiC superjunction structure is employed to improve device figure of merit. Performance of the novel optically controlled power transistor was simulated using Silvaco Atlas tools, which has shown that the device has a very good response to the visible light and the near infrared light. The optoelectronic responsivities of the device at 0.5 μm and 0.7 μm are 330 mA/W and 76.2 mA/W at 2 V based voltage, respectively. (semiconductor devices)

  12. An optically controlled SiC lateral power transistor based on SiC/SiCGe super junction structure

    Energy Technology Data Exchange (ETDEWEB)

    Pu Hongbin; Cao Lin; Ren Jie; Chen Zhiming; Nan Yagong, E-mail: puhongbin@xaut.edu.c [Xi' an University of Technology, Xi' an 710048 (China)

    2010-04-15

    An optically controlled SiC/SiCGe lateral power transistor based on superjunction structure has been proposed, in which n-SiCGe/p-SiC superjunction structure is employed to improve device figure of merit. Performance of the novel optically controlled power transistor was simulated using Silvaco Atlas tools, which has shown that the device has a very good response to the visible light and the near infrared light. The optoelectronic responsivities of the device at 0.5 {mu}m and 0.7 {mu}m are 330 mA/W and 76.2 mA/W at 2 V based voltage, respectively. (semiconductor devices)

  13. Programmable automated transistor test system

    International Nuclear Information System (INIS)

    Truong, L.V.; Sundberg, G.R.

    1986-01-01

    The paper describes a programmable automated transistor test system (PATTS) and its utilization to evaluate bipolar transistors and Darlingtons, and such MOSFET and special types as can be accommodated with the PATTS base-drive. An application of a pulsed power technique at low duty cycles in a non-destructive test is used to examine the dynamic switching characteristic curves of power transistors. Data collection, manipulation, storage, and output are operator interactive but are guided and controlled by the system software. In addition a library of test data is established on disks, tapes, and hard copies for future reference

  14. Quantum Thermal Transistor.

    Science.gov (United States)

    Joulain, Karl; Drevillon, Jérémie; Ezzahri, Younès; Ordonez-Miranda, Jose

    2016-05-20

    We demonstrate that a thermal transistor can be made up with a quantum system of three interacting subsystems, coupled to a thermal reservoir each. This thermal transistor is analogous to an electronic bipolar one with the ability to control the thermal currents at the collector and at the emitter with the imposed thermal current at the base. This is achieved by determining the heat fluxes by means of the strong-coupling formalism. For the case of three interacting spins, in which one of them is coupled to the other two, that are not directly coupled, it is shown that high amplification can be obtained in a wide range of energy parameters and temperatures. The proposed quantum transistor could, in principle, be used to develop devices such as a thermal modulator and a thermal amplifier in nanosystems.

  15. Structure and Process of Infrared Hot Electron Transistor Arrays

    Directory of Open Access Journals (Sweden)

    Richard Fu

    2012-05-01

    Full Text Available An infrared hot-electron transistor (IHET 5 × 8 array with a common base configuration that allows two-terminal readout integration was investigated and fabricated for the first time. The IHET structure provides a maximum factor of six in improvement in the photocurrent to dark current ratio compared to the basic quantum well infrared photodetector (QWIP, and hence it improved the array S/N ratio by the same factor. The study also showed for the first time that there is no electrical cross-talk among individual detectors, even though they share the same emitter and base contacts. Thus, the IHET structure is compatible with existing electronic readout circuits for photoconductors in producing sensitive focal plane arrays.

  16. Thienoacene-fused pentalenes: Syntheses, structures, physical properties and applications for organic field-effect transistors

    KAUST Repository

    Dai, Gaole

    2014-11-27

    Three soluble and stable thienoacene-fused pentalene derivatives (1-3) with different π-conjugation lengths were synthesized. X-ray crystallographic analysis and density functional theory (DFT) calculations revealed their unique geometric and electronic structures due to the interaction between the aromatic thienoacene units and antiaromatic pentalene moiety. As a result, they all possess a small energy gap and show amphoteric redox behaviour. Time dependent (TD) DFT calculations were used to explain their unique electronic absorption spectra. These new compounds exhibited good thermal stability and ordered packing in solid state and thus their applications in organic field-effect transistors (OFETs) were also investigated. The highest field-effect hole mobility of 0.016, 0.036 and 0.001 cm2 V-1 s-1 was achieved for solution-processed thin films of 1-3, respectively.

  17. Dianthraceno[a,e]pentalenes: Synthesis, crystallographic structures and applications in organic field-effect transistors

    KAUST Repository

    Dai, Gaole

    2015-01-01

    Two soluble and stable dianthraceno[a,e]pentalenes with two (DAP1) and six (DAP2) phenyl substituents were synthesized. Both compounds possess a small energy band gap and show amphoteric redox behaviour due to intramolecular donor-accepter interactions. X-ray crystallographic analysis revealed that DAP2 has a closely packed structure with multi-dimensional [C-H⋯π] interactions although there are no π-π interactions between the dianthraceno[a,e]pentalene cores. As a result, solution-processed field effect transistors based on DAP2 exhibited an average hole mobility of 0.65 cm2 V-1 s-1. Under similar conditions, DAP1 showed an average field effect hole mobility of 0.001 cm2 V-1 s-1. This journal is

  18. Charge collection mechanisms in MOS/SOI transistors irradiated by energetic heavy ions

    International Nuclear Information System (INIS)

    Musseau, O.; Leray, J.L.; Ferlet, V.; Umbert, A.; Coic, Y.M.; Hesto, P.

    1991-01-01

    We have investigated with both experimental and numerical methods (Monte Carlo and drift-diffusion models) various charge collection mechanisms in NMOS/SOI transistors irradiated by single energetic heavy ions. Our physical interpretations of data emphasize the influence of various parasitic structures of the device. Two charge collection mechanisms are detailed: substrate funneling in buried MOS capacitor and latching of the parasitic bipolar transistor. Based on carrier transport and charge collection, the sensitivity of future scaled down CMOS/SOI technologies is finally discussed

  19. Atomtronics and basic logic: Constructing AND and OR gates from atomtronic transistors

    Science.gov (United States)

    Pepino, Ronald; Cooper, John; Anderson, Dana; Holland, Murray

    2008-05-01

    Our atomtronics research focuses on creating an analogy of electronic devices and circuits with ultracold atoms. Such an analogy arises from the highly tunable band structure of ultracold neutral atoms trapped in optical lattices. In previous work it has been demonstrated that the electronic behavior of a diode, field effect transistor (FET), and bipolar junction transistor (BJT) can all be realized in systems composed of optical lattices connected to reservoirs of neutral, ultracold atoms. We demonstrate that the behavior of simple logic gates namely, the AND and OR gates, can be realized by connecting the BJTs in the traditional electronic manner.

  20. Reduction of Power Dissipation in Dynamic BiCMOS Logic Gates by Transistor Reordering

    Directory of Open Access Journals (Sweden)

    S. M. Rezaul Hasan

    2002-01-01

    Full Text Available This paper explores the deterministic transistor reordering in low-voltage dynamic BiCMOS logic gates, for reducing the dynamic power dissipation. The constraints of load driving (discharging capability and NPN turn-on delay for MOSFET reordered structures has been carefully considered. Simulations shows significant reduction in the dynamic power dissipation for the transistor reordered BiCMOS structures. The power-delay product figure-of-merit is found to be significantly enhanced without any associated silicon-area penalty. In order to experimentally verify the reduction in power dissipation, original and reordered structures were fabricated using the MOSIS 2 μm N-well analog CMOS process which has a P-base layer for bipolar NPN option. Measured results shows a 20% reduction in the power dissipation for the transistor reordered structure, which is in close agreement with the simulation.

  1. P-type CuxS thin films: Integration in a thin film transistor structure

    International Nuclear Information System (INIS)

    Nunes de Carvalho, C.; Parreira, P.; Lavareda, G.; Brogueira, P.; Amaral, A.

    2013-01-01

    Cu x S thin films, 80 nm thick, are deposited by vacuum thermal evaporation of sulfur-rich powder mixture, Cu 2 S:S (50:50 wt.%) with no intentional heating of the substrate. The process of deposition occurs at very low deposition rates (0.1–0.3 nm/s) to avoid the formation of Cu or S-rich films. The evolution of Cu x S films surface properties (morphology/roughness) under post deposition mild annealing in air at 270 °C and their integration in a thin film transistor (TFT) are the main objectives of this study. Accordingly, Scanning Electron Microscopy studies show Cu x S films with different surface morphologies, depending on the post deposition annealing conditions. For the shortest annealing time, the Cu x S films look to be constructed of grains with large dimension at the surface (approximately 100 nm) and consequently, irregular shape. For the longest annealing time, films with a fine-grained surface are found, with some randomly distributed large particles bound to this fine-grained surface. Atomic Force Microscopy results indicate an increase of the root-mean-square roughness of Cu x S surface with annealing time, from 13.6 up to 37.4 nm, for 255 and 345 s, respectively. The preliminary integration of Cu x S films in a TFT bottom-gate type structure allowed the study of the feasibility and compatibility of this material with the remaining stages of a TFT fabrication as well as the determination of the p-type characteristic of the Cu x S material. - Highlights: • Surface properties of annealed Cu x S films. • Variation of conductivity with annealing temperatures of Cu x S films. • Application of evaporated Cu x S films in a thin film transistor (TFT) structure. • Determination of Cu x S p-type characteristic from TFT behaviour

  2. Transistor scaling with novel materials

    OpenAIRE

    Meikei Ieong; Vijay Narayanan; Dinkar Singh; Anna Topol; Victor Chan; Zhibin Ren

    2006-01-01

    Complementary metal-oxide-semiconductor (CMOS) transistor scaling will continue for at least another decade. However, innovation in transistor structures and integration of novel materials are needed to sustain this performance trend. Here we discuss the challenges and opportunities of transistor scaling for the next five to ten years.

  3. Experimental characterization of the dominant multiple nodes charge collection mechanism in metal oxide-semiconductor transistors

    Science.gov (United States)

    Song, Ruiqiang; Chen, Shuming; Chi, Yaqing; Wu, Zhenyu; Liang, Bin; Chen, Jianjun; Xu, Jingyan; Hao, Peipei; Yu, Junting

    2017-06-01

    We propose an experimental method to investigate the dominant multiple node charge collection mechanism. A transistor array-based test structure is used to distinguish charge collection owing to the drift-diffusion and parasitic bipolar amplification effect. Heavy ion experimental results confirm that drift-diffusion dominates multiple node charge collection at low linear energy transfer (LET). However, the parasitic bipolar amplification effect dominates it at high LET. We also propose simple equations to determine the critical LET which may change the dominant multiple node charge collection mechanism. The calculated LET value is consistent with the heavy ion experimental results.

  4. Can structural MRI aid in clinical classification? A machine learning study in two independent samples of patients with schizophrenia, bipolar disorder and healthy subjects.

    Science.gov (United States)

    Schnack, Hugo G; Nieuwenhuis, Mireille; van Haren, Neeltje E M; Abramovic, Lucija; Scheewe, Thomas W; Brouwer, Rachel M; Hulshoff Pol, Hilleke E; Kahn, René S

    2014-01-01

    Although structural magnetic resonance imaging (MRI) has revealed partly non-overlapping brain abnormalities in schizophrenia and bipolar disorder, it is unknown whether structural MRI scans can be used to separate individuals with schizophrenia from those with bipolar disorder. An algorithm capable of discriminating between these two disorders could become a diagnostic aid for psychiatrists. Here, we scanned 66 schizophrenia patients, 66 patients with bipolar disorder and 66 healthy subjects on a 1.5T MRI scanner. Three support vector machines were trained to separate patients with schizophrenia from healthy subjects, patients with schizophrenia from those with bipolar disorder, and patients with bipolar disorder from healthy subjects, respectively, based on their gray matter density images. The predictive power of the models was tested using cross-validation and in an independent validation set of 46 schizophrenia patients, 47 patients with bipolar disorder and 43 healthy subjects scanned on a 3T MRI scanner. Schizophrenia patients could be separated from healthy subjects with an average accuracy of 90%. Additionally, schizophrenia patients and patients with bipolar disorder could be distinguished with an average accuracy of 88%.The model delineating bipolar patients from healthy subjects was less accurate, correctly classifying 67% of the healthy subjects and only 53% of the patients with bipolar disorder. In the latter group, lithium and antipsychotics use had no influence on the classification results. Application of the 1.5T models on the 3T validation set yielded average classification accuracies of 76% (healthy vs schizophrenia), 66% (bipolar vs schizophrenia) and 61% (healthy vs bipolar). In conclusion, the accurate separation of schizophrenia from bipolar patients on the basis of structural MRI scans, as demonstrated here, could be of added value in the differential diagnosis of these two disorders. The results also suggest that gray matter pathology in

  5. Plasmonic terahertz detection by a double-grating-gate field-effect transistor structure with an asymmetric unit cell

    OpenAIRE

    Popov, V. V.; Fateev, D. V.; Otsuji, T.; Meziani, Y. M.; Coquillat, D.; Knap, W.

    2011-01-01

    Plasmonic terahertz detection by a double-grating gate field-effect transistor structure with an asymmetric unit cell is studied theoretically. Detection responsivity exceeding 8 kV/W at room temperature in the photovoltaic response mode is predicted for strong asymmetry of the structure unit cell. This value of the responsivity is an order of magnitude greater than reported previously for the other types of uncooled plasmonic terahertz detectors. Such enormous responsivity can be obtained wi...

  6. Nonvolatile field effect transistors based on protons and Si/SiO2Si structures

    International Nuclear Information System (INIS)

    Warren, W.L.; Vanheusden, K.; Fleetwood, D.M.; Schwank, J.R.; Winokur, P.S.; Knoll, M.G.; Devine, R.A.B.

    1997-01-01

    Recently, the authors have demonstrated that annealing Si/SiO 2 /Si structures in a hydrogen containing ambient introduces mobile H + ions into the buried SiO 2 layer. Changes in the H + spatial distribution within the SiO 2 layer were electrically monitored by current-voltage (I-V) measurements. The ability to directly probe reversible protonic motion in Si/SiO 2 /Si structures makes this an exemplar system to explore the physics and chemistry of hydrogen in the technologically relevant Si/SiO 2 structure. In this work, they illustrate that this effect can be used as the basis for a programmable nonvolatile field effect transistor (NVFET) memory that may compete with other Si-based memory devices. The power of this novel device is its simplicity; it is based upon standard Si/SiO 2 /Si technology and forming gas annealing, a common treatment used in integrated circuit processing. They also briefly discuss the effects of radiation on its retention properties

  7. Insulated gate and surface passivation structures for GaN-based power transistors

    Science.gov (United States)

    Yatabe, Zenji; Asubar, Joel T.; Hashizume, Tamotsu

    2016-10-01

    Recent years have witnessed GaN-based devices delivering their promise of unprecedented power and frequency levels and demonstrating their capability as an able replacement for Si-based devices. High-electron-mobility transistors (HEMTs), a key representative architecture of GaN-based devices, are well-suited for high-power and high frequency device applications, owing to highly desirable III-nitride physical properties. However, these devices are still hounded by issues not previously encountered in their more established Si- and GaAs-based devices counterparts. Metal-insulator-semiconductor (MIS) structures are usually employed with varying degrees of success in sidestepping the major problematic issues such as excessive leakage current and current instability. While different insulator materials have been applied to GaN-based transistors, the properties of insulator/III-N interfaces are still not fully understood. This is mainly due to the difficulty of characterizing insulator/AlGaN interfaces in a MIS HEMT because of the two resulting interfaces: insulator/AlGaN and AlGaN/GaN, making the potential modulation rather complicated. Although there have been many reports of low interface-trap densities in HEMT MIS capacitors, several papers have incorrectly evaluated their capacitance-voltage (C-V) characteristics. A HEMT MIS structure typically shows a 2-step C-V behavior. However, several groups reported C-V curves without the characteristic step at the forward bias regime, which is likely to the high-density states at the insulator/AlGaN interface impeding the potential control of the AlGaN surface by the gate bias. In this review paper, first we describe critical issues and problems including leakage current, current collapse and threshold voltage instability in AlGaN/GaN HEMTs. Then we present interface properties, focusing on interface states, of GaN MIS systems using oxides, nitrides and high-κ dielectrics. Next, the properties of a variety of AlGaN/GaN MIS

  8. Insulated gate and surface passivation structures for GaN-based power transistors

    International Nuclear Information System (INIS)

    Yatabe, Zenji; Asubar, Joel T; Hashizume, Tamotsu

    2016-01-01

    Recent years have witnessed GaN-based devices delivering their promise of unprecedented power and frequency levels and demonstrating their capability as an able replacement for Si-based devices. High-electron-mobility transistors (HEMTs), a key representative architecture of GaN-based devices, are well-suited for high-power and high frequency device applications, owing to highly desirable III-nitride physical properties. However, these devices are still hounded by issues not previously encountered in their more established Si- and GaAs-based devices counterparts. Metal–insulator–semiconductor (MIS) structures are usually employed with varying degrees of success in sidestepping the major problematic issues such as excessive leakage current and current instability. While different insulator materials have been applied to GaN-based transistors, the properties of insulator/III-N interfaces are still not fully understood. This is mainly due to the difficulty of characterizing insulator/AlGaN interfaces in a MIS HEMT because of the two resulting interfaces: insulator/AlGaN and AlGaN/GaN, making the potential modulation rather complicated. Although there have been many reports of low interface-trap densities in HEMT MIS capacitors, several papers have incorrectly evaluated their capacitance–voltage ( C – V ) characteristics. A HEMT MIS structure typically shows a 2-step C – V behavior. However, several groups reported C – V curves without the characteristic step at the forward bias regime, which is likely to the high-density states at the insulator/AlGaN interface impeding the potential control of the AlGaN surface by the gate bias. In this review paper, first we describe critical issues and problems including leakage current, current collapse and threshold voltage instability in AlGaN/GaN HEMTs. Then we present interface properties, focusing on interface states, of GaN MIS systems using oxides, nitrides and high- κ dielectrics. Next, the properties of a

  9. BDNF and BMI effects on brain structures of bipolar offspring: results from the global mood and brain science initiative.

    Science.gov (United States)

    Mansur, R B; Brietzke, E; McIntyre, R S; Cao, B; Lee, Y; Japiassú, L; Chen, K; Lu, R; Lu, W; Li, T; Xu, G; Lin, K

    2017-12-01

    To compare brain-derived neurotrophic factor (BDNF) levels between offspring of individuals with bipolar disorders (BD) and healthy controls (HCs) and investigate the effects of BDNF levels and body mass index (BMI) on brain structures. Sixty-seven bipolar offspring and 45 HCs were included (ages 8-28). Structural images were acquired using 3.0 Tesla magnetic resonance imaging. Serum BDNF levels were measured using enzyme-linked immunosorbent assay. Multivariate and univariate analyses of covariance were conducted. Significantly higher BDNF levels were observed among bipolar offspring, relative to HCs (P > 0.025). Offspring status moderated the association between BDNF and BMI (F 1 =4.636, P = 0.034). After adjustment for relevant covariates, there was a trend for a significant interaction of group and BDNF on neuroimaging parameters (Wilks'λ F 56,94 =1.463, P = 0.052), with significant effects on cerebellar white matter and superior and middle frontal regions. Brain volume and BDNF were positively correlated among HCs and negatively correlated among bipolar offspring. Interactions between BDNF and BMI on brain volumes were non-significant among HCs (Wilks'λ F 28,2 =2.229, P = 0.357), but significant among bipolar offspring (Wilks'λ F 28,12 =2.899, P = 0.028). Offspring status and BMI moderate the association between BDNF levels and brain structures among bipolar offspring, underscoring BDNF regulation and overweight/obesity as key moderators of BD pathogenesis. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. Amorphous Oxide Thin Film Transistors with Nitrogen-Doped Hetero-Structure Channel Layers

    Directory of Open Access Journals (Sweden)

    Haiting Xie

    2017-10-01

    Full Text Available The nitrogen-doped amorphous oxide semiconductor (AOS thinfilm transistors (TFTs with double-stacked channel layers (DSCL were prepared and characterized. The DSCL structure was composed of nitrogen-doped amorphous InGaZnO and InZnO films (a-IGZO:N/a-IZO:N or a-IZO:N/a-IGZO:N and gave the corresponding TFT devices large field-effect mobility due to the presence of double conduction channels. The a-IZO:N/a-IGZO:N TFTs, in particular, showed even better electrical performance (µFE = 15.0 cm2・V−1・s−1, SS = 0.5 V/dec, VTH = 1.5 V, ION/IOFF = 1.1 × 108 and stability (VTH shift of 1.5, −0.5 and −2.5 V for positive bias-stress, negative bias-stress, and thermal stress tests, respectively than the a-IGZO:N/a-IZO:N TFTs. Based on the X-ray photoemission spectroscopy measurements and energy band analysis, we assumed that the optimized interface trap states, the less ambient gas adsorption, and the better suppression of oxygen vacancies in the a-IZO:N/a-IGZO:N hetero-structures might explain the better behavior of the corresponding TFTs.

  11. Correlation between crystal structure and mobility in organic field-effect transistors based on single crystals of tetrathiafulvalene derivatives.

    Science.gov (United States)

    Mas-Torrent, Marta; Hadley, Peter; Bromley, Stefan T; Ribas, Xavi; Tarrés, Judit; Mas, Montserrat; Molins, Elies; Veciana, Jaume; Rovira, Concepció

    2004-07-14

    Recently, it was reported that crystals of the organic material dithiophene-tetrathiafulvalene (DT-TTF) have a high field-effect charge carrier mobility of 1.4 cm(2)/(V x s). These crystals were formed by a simple drop-casting method, making this material interesting to investigate for possible applications in low-cost electronics. Here, organic single-crystal field-effect transistors based on materials related to DT-TTF are presented and a clear correlation between the crystal structure and the electrical characteristics is observed. The observed relationship between the mobilities in the different crystal structures is strongly corroborated by calculations of both the molecular reorganization energies and the maximum intermolecular transfer integrals. The most suitable materials described here exhibit mobilities that are among the highest reported for organic field-effect transistors and that are the highest reported for solution-processed materials.

  12. Schottky bipolar I-MOS: An I-MOS with Schottky electrodes and an open-base BJT configuration for reduced operating voltage

    Science.gov (United States)

    Kannan, N.; Kumar, M. Jagadesh

    2017-04-01

    In this paper, we have proposed a novel impact ionization MOS (I-MOS) structure, called the Schottky bipolar I-MOS, with Schottky source and drain electrodes and utilizing the open-base bipolar junction transistor (BJT) configuration for achieving reduction in the operating voltage of the I-MOS transistor. We report, using 2-D simulations, a low operating voltage (∼1.1 V) and a low subthreshold swing (∼3.6 mV/Decade). For the corresponding p-i-n I-MOS, the operating voltage is ∼5.5 V. The operating voltage of the Schottky bipolar I-MOS is the lowest reported operating voltage for silicon based I-MOS transistors. The nearly 80% reduction in the operating voltage of the Schottky bipolar I-MOS makes it suitable for applications requiring low operating voltages. The Schottky bipolar I-MOS is also expected to have an improved reliability over the p-i-n I-MOS since high energy carriers, induced by impact ionization near the drain, do not have to pass under the gate region in the channel. The use of Schottky contacts instead of heavily doped source and drain regions and the low channel doping level reduces the required thermal budget for device fabrication. The low operating voltage, low subthreshold swing and possibly improved reliability of the Schottky bipolar I-MOS, makes it a potential solution for applications where steep subthreshold slope transistors are being explored as alternative to the conventional MOS transistor.

  13. Cross-Sectional and Longitudinal Abnormalities in Brain Structure in Children with Severe Mood Dysregulation or Bipolar Disorder

    Science.gov (United States)

    Adleman, Nancy E.; Fromm, Stephen J.; Razdan, Varun; Kayser, Reilly; Dickstein, Daniel P.; Brotman, Melissa A.; Pine, Daniel S.; Leibenluft, Ellen

    2012-01-01

    Background: There is debate as to whether chronic irritability (operationalized as severe mood dysregulation, SMD) is a developmental form of bipolar disorder (BD). Although structural brain abnormalities in BD have been demonstrated, no study compares neuroanatomy among SMD, BD, and healthy volunteers (HV) either cross-sectionally or over time.…

  14. Relation between Amygdala Structure and Function in Adolescents with Bipolar Disorder

    Science.gov (United States)

    Kalmar, Jessica H.; Wang, Fei; Chepenik, Lara G.; Womer, Fay Y.; Jones, Monique M.; Pittman, Brian; Shah, Maulik P.; Martin, Andres; Constable, R. Todd; Blumberg, Hilary P.

    2009-01-01

    Adolescents with bipolar disorder showed decreased amygdala volume and increased amygdala response to emotional faces. Amygdala volume is inversely related to activation during emotional face processing.

  15. Structure-Property Relationships of Semiconducting Polymers for Flexible and Durable Polymer Field-Effect Transistors.

    Science.gov (United States)

    Kim, Min Je; Jung, A-Ra; Lee, Myeongjae; Kim, Dongjin; Ro, Suhee; Jin, Seon-Mi; Nguyen, Hieu Dinh; Yang, Jeehye; Lee, Kyung-Koo; Lee, Eunji; Kang, Moon Sung; Kim, Hyunjung; Choi, Jong-Ho; Kim, BongSoo; Cho, Jeong Ho

    2017-11-22

    We report high-performance top-gate bottom-contact flexible polymer field-effect transistors (FETs) fabricated by flow-coating diketopyrrolopyrrole (DPP)-based and naphthalene diimide (NDI)-based polymers (P(DPP2DT-T2), P(DPP2DT-TT), P(DPP2DT-DTT), P(NDI2OD-T2), P(NDI2OD-F2T2), and P(NDI2OD-Se2)) as semiconducting channel materials. All of the polymers displayed good FET characteristics with on/off current ratios exceeding 10 7 . The highest hole mobility of 1.51 cm 2 V -1 s -1 and the highest electron mobility of 0.85 cm 2 V -1 s -1 were obtained from the P(DPP2DT-T2) and P(NDI2OD-Se2) polymer FETs, respectively. The impacts of the polymer structures on the FET performance are well-explained by the interplay between the crystallinity, the tendency of the polymer backbone to adopt an edge-on orientation, and the interconnectivity of polymer fibrils in the film state. Additionally, we demonstrated that all of the flexible polymer-based FETs were highly resistant to tensile stress, with negligible changes in their carrier mobilities and on/off ratios after a bending test. Conclusively, these high-performance, flexible, and durable FETs demonstrate the potential of semiconducting conjugated polymers for use in flexible electronic applications.

  16. High Resolution Inkjet Printed Oxide Thin Film Transistors with Self-Aligned Fine Channel Bank Structure.

    Science.gov (United States)

    Zhang, Qing; Shao, Shuangshuang; Chen, Zheng; Pecunia, Vincenzo; Xia, Kai; Zhao, Jianwen; Cui, Zheng

    2018-04-12

    A self-aligned inkjet printing process has been developed to construct small channel metal oxide (a-IGZO) thin-film transistors (TFTs) with independent bottom gates on transparent glass substrates. Poly(methylsilsesquioxane) (PMSQ) was used to pattern hydrophobic banks on the transparent substrate instead of commonly used self-assembled octadecyltrichlorosilane (OTS). Photolithographic exposure from backside using bottom gate electrodes as mask formed hydrophilic channel areas for the TFTs. IGZO ink was selectively deposited by an inkjet printer in the hydrophilic channel region and confined by the hydrophobic bank structure, resulting in the precise deposition of semiconductor layers just above the gate electrodes. Inkjet-printed IGZO TFTs with independent gate electrodes of 10 μm width have been demonstrated, avoiding completely printed channel beyond the broad of the gate electrodes. The TFTs showed on/off ratios of 10 8 , maximum mobility of 3.3 cm 2 V -1 s -1 , negligible hysteresis and good uniformity. This method is conductive to minimizing the area of printed TFTs so as to the development of high resolution printing displays.

  17. Vertical organic transistors

    Science.gov (United States)

    Lüssem, Björn; Günther, Alrun; Fischer, Axel; Kasemann, Daniel; Leo, Karl

    2015-11-01

    Organic switching devices such as field effect transistors (OFETs) are a key element of future flexible electronic devices. So far, however, a commercial breakthrough has not been achieved because these devices usually lack in switching speed (e.g. for logic applications) and current density (e.g. for display pixel driving). The limited performance is caused by a combination of comparatively low charge carrier mobilities and the large channel length caused by the need for low-cost structuring. Vertical Organic Transistors are a novel technology that has the potential to overcome these limitations of OFETs. Vertical Organic Transistors allow to scale the channel length of organic transistors into the 100 nm regime without cost intensive structuring techniques. Several different approaches have been proposed in literature, which show high output currents, low operation voltages, and comparatively high speed even without sub-μm structuring technologies. In this review, these different approaches are compared and recent progress is highlighted.

  18. Plasmonic terahertz detection by a double-grating-gate field-effect transistor structure with an asymmetric unit cell

    Science.gov (United States)

    Popov, V. V.; Fateev, D. V.; Otsuji, T.; Meziani, Y. M.; Coquillat, D.; Knap, W.

    2011-12-01

    Plasmonic terahertz detection by a double-grating gate field-effect transistor structure with an asymmetric unit cell is studied theoretically. Detection responsivity exceeding 8 kV/W at room temperature in the photovoltaic response mode is predicted for strong asymmetry of the structure unit cell. This value of the responsivity is an order of magnitude greater than reported previously for the other types of uncooled plasmonic terahertz detectors. Such enormous responsivity can be obtained without using any supplementary antenna elements because the double-grating gate acts as an aerial matched antenna that effectively couples the incoming terahertz radiation to plasma oscillations in the structure channel.

  19. The Smallest Transistor-Based Nonautonomous Chaotic Circuit

    DEFF Research Database (Denmark)

    Lindberg, Erik; Murali, K.; Tamasevicius, Arunas

    2005-01-01

    A nonautonomous chaotic circuit based on one transistor, two capacitors, and two resistors is described. The mechanism behind the chaotic performance is based on “disturbance of integration.” The forward part and the reverse part of the bipolar transistor are “fighting” about the charging...

  20. On the 50th Anniversary of the Transistor

    DEFF Research Database (Denmark)

    Stassen, Flemming

    1997-01-01

    This paper celebrates the 50th anniversary of the invention of the bipolar transistor in 1947. Combined with the inventions of integration and planar technology, the invention of the transistor marks the beginning of a period of unprecedented growth, the industrialization of electronics....

  1. Application of the Johnson criteria to graphene transistors

    International Nuclear Information System (INIS)

    Kelly, M J

    2013-01-01

    For 60 years, the Johnson criteria have guided the development of materials and the materials choices for field-effect and bipolar transistor technology. Intrinsic graphene is a semi-metal, precluding transistor applications, but only under lateral bias is a gap opened and transistor action possible. This first application of the Johnson criteria to biased graphene suggests that this material will struggle to ever achieve competitive commercial applications. (fast track communication)

  2. Unijunction transistors

    International Nuclear Information System (INIS)

    1981-01-01

    The electrical characteristics of unijunction transistors can be modified by irradiation with electron beams in excess of 400 KeV and at a dose rate of 10 13 to 10 16 e/cm 2 . Examples are given of the effect of exposing the emitter-base junctions of transistors to such lattice defect causing radiation for a time sufficient to change the valley current of the transistor. (U.K.)

  3. Structural and functional changes in the somatosensory cortex in euthymic females with bipolar disorder.

    Science.gov (United States)

    Minuzzi, Luciano; Syan, Sabrina K; Smith, Mara; Hall, Alexander; Hall, Geoffrey Bc; Frey, Benicio N

    2017-12-01

    Current evidence from neuroimaging data suggests possible dysfunction of the fronto-striatal-limbic circuits in individuals with bipolar disorder. Somatosensory cortical function has been implicated in emotional recognition, risk-taking and affective responses through sensory modalities. This study investigates anatomy and function of the somatosensory cortex in euthymic bipolar women. In total, 68 right-handed euthymic women (bipolar disorder = 32 and healthy controls = 36) between 16 and 45 years of age underwent high-resolution anatomical and functional magnetic resonance imaging during the mid-follicular menstrual phase. The somatosensory cortex was used as a seed region for resting-state functional connectivity analysis. Voxel-based morphometry was used to evaluate somatosensory cortical gray matter volume between groups. We found increased resting-state functional connectivity between the somatosensory cortex and insular cortex, inferior prefrontal gyrus and frontal orbital cortex in euthymic bipolar disorder subjects compared to healthy controls. Voxel-based morphometry analysis showed decreased gray matter in the left somatosensory cortex in the bipolar disorder group. Whole-brain voxel-based morphometry analysis controlled by age did not reveal any additional significant difference between groups. This study is the first to date to evaluate anatomy and function of the somatosensory cortex in a well-characterized sample of euthymic bipolar disorder females. Anatomical and functional changes in the somatosensory cortex in this population might contribute to the pathophysiology of bipolar disorder.

  4. Antiferromagnetic bipolar semiconductor LaMnPO with ZrCuSiAs-type structure

    Science.gov (United States)

    Yanagi, Hiroshi; Watanabe, Takumi; Kodama, Katsuaki; Iikubo, Satoshi; Shamoto, Shin-ichi; Kamiya, Toshio; Hirano, Masahiro; Hosono, Hideo

    2009-05-01

    Electronic and magnetic properties of a layered compound LaMnPO are examined in relation to a newly discovered iso-structural superconductor LaFeAs(P)O. Neutron diffraction measurements, together with temperature dependent magnetic susceptibility, clarify that LaMnPO is an antiferromagnet at least up to 375 K. The spin moment of a Mn ion is determined to be 2.26 μB at room temperature, and the spin configuration is antiparallel in the Mn-P plane and parallel between the Mn-P planes, which is rather different from that of LaFeAsO. Optical absorption spectra, photoemission spectra, and temperature dependent electrical conductivity indicate that LaMnPO is a semiconductor. Furthermore, nominally undoped LaMnPO exhibits n-type conduction while the conduction type is changed by doping of Cu or Ca to the La sites, indicating that LaMnPO is a bipolar conductor. Density functional calculation using the GGA+U approximation supports the above conclusions; the electronic band structure has an open band gap and the antiferromagnetic spin configuration is more stable than the ferromagnetic one.

  5. T-Shaped Emitter Metal Structures for HBTs

    Science.gov (United States)

    Fung, King Man; Samoska, Lorene; Velebir, James; Muller, Richard; Echternach, Pierre; Siegel, Peter; Smith, Peter; Martin, Suzanne; Malik, Roger; Rodwell, Mark; hide

    2006-01-01

    Metal emitter structures in a class of developmental InP-based high-speed heterojunction bipolar transistors (HBTs) have been redesigned to have T-shaped cross sections. T-cross-section metal features have been widely used in Schottky diodes and high-electron-mobility transistors, but not in HBTs. As explained, the purpose served by the present T cross-sectional shapes is to increase fabrication yields beyond those achievable with the prior cross-sectional shapes.

  6. Adjustable threshold-voltage in all-inkjet-printed organic thin film transistor using double-layer dielectric structures

    International Nuclear Information System (INIS)

    Wu, Wen-Jong; Lee, Chang-Hung; Hsu, Chun-Hao; Yang, Shih-Hsien; Lin, Chih-Ting

    2013-01-01

    An all-inkjet-printed organic thin film transistor (OTFT) with a double-layer dielectric structure is proposed and implemented in this study. By using the double-layer structure with different dielectric materials (i.e., polyvinylphenol with poly(vinylidene fluoride-co-hexafluoropropylene)), the threshold-voltage of OTFT can be adjusted. The threshold-voltage shift can be controlled by changing the composition of dielectric layers. That is, an enhancement-mode OTFT can be converted to a depletion-mode OTFT by selectively printing additional dielectric layers to form a high-k/low-k double-layer structure. The printed OTFT has a carrier mobility of 5.0 × 10 −3 cm 2 /V-s. The threshold-voltages of the OTFTs ranged between − 13 V and 10 V. This study demonstrates an additional design parameter for organic electronics manufactured using inkjet printing technology. - Highlights: • A double-layer dielectric organic thin film transistor, OTFT, is implemented. • The threshold voltage of OTFT can be configured by the double dielectric structure. • The composition of the dielectric determines the threshold voltage shift. • The characteristics of OTFTs can be adjusted by double dielectric structures

  7. Magnetic Vortex Based Transistor Operations

    Science.gov (United States)

    Kumar, D.; Barman, S.; Barman, A.

    2014-01-01

    Transistors constitute the backbone of modern day electronics. Since their advent, researchers have been seeking ways to make smaller and more efficient transistors. Here, we demonstrate a sustained amplification of magnetic vortex core gyration in coupled two and three vortices by controlling their relative core polarities. This amplification is mediated by a cascade of antivortex solitons travelling through the dynamic stray field. We further demonstrated that the amplification can be controlled by switching the polarity of the middle vortex in a three vortex sequence and the gain can be controlled by the input signal amplitude. An attempt to show fan–out operation yielded gain for one of the symmetrically placed branches which can be reversed by switching the core polarity of all the vortices in the network. The above observations promote the magnetic vortices as suitable candidates to work as stable bipolar junction transistors (BJT). PMID:24531235

  8. Magnetic Vortex Based Transistor Operations

    Science.gov (United States)

    Kumar, D.; Barman, S.; Barman, A.

    2014-02-01

    Transistors constitute the backbone of modern day electronics. Since their advent, researchers have been seeking ways to make smaller and more efficient transistors. Here, we demonstrate a sustained amplification of magnetic vortex core gyration in coupled two and three vortices by controlling their relative core polarities. This amplification is mediated by a cascade of antivortex solitons travelling through the dynamic stray field. We further demonstrated that the amplification can be controlled by switching the polarity of the middle vortex in a three vortex sequence and the gain can be controlled by the input signal amplitude. An attempt to show fan-out operation yielded gain for one of the symmetrically placed branches which can be reversed by switching the core polarity of all the vortices in the network. The above observations promote the magnetic vortices as suitable candidates to work as stable bipolar junction transistors (BJT).

  9. The relationship between genetic risk variants with brain structure and function in bipolar disorder

    DEFF Research Database (Denmark)

    Pereira, Licia P; Köhler, Cristiano A; de Sousa, Rafael T

    2017-01-01

    Genetic-neuroimaging paradigms could provide insights regarding the pathophysiology of bipolar disorder (BD). Nevertheless, findings have been inconsistent across studies. A systematic review of gene-imaging studies involving individuals with BD was conducted across electronic major databases from...

  10. Superconducting transistor

    International Nuclear Information System (INIS)

    Gray, K.E.

    1978-01-01

    A three film superconducting tunneling device, analogous to a semiconductor transistor, is presented, including a theoretical description and experimental results showing a current gain of four. Much larger current gains are shown to be feasible. Such a development is particularly interesting because of its novelty and the striking analogies with the semiconductor junction transistor

  11. Bipolar Disorder

    Science.gov (United States)

    Bipolar disorder is a serious mental illness. People who have it go through unusual mood changes. They go ... The down feeling is depression. The causes of bipolar disorder aren't always clear. It runs in families. ...

  12. Specifics of Pulsed Arc Welding Power Supply Performance Based On A Transistor Switch

    OpenAIRE

    Krampit, Nataliya Yurievna; Kust, Tatiana Sergeevna; Krampit, Maksim Andreevich

    2016-01-01

    Specifics of designing a pulsed arc welding power supply device are presented in the paper. Electronic components for managing large current was analyzed. Strengths and shortcomings of power supply circuits based on thyristor, bipolar transistor and MOSFET are outlined. As a base unit for pulsed arc welding was chosen MOSFET transistor, which is easy to manage. Measures to protect a transistor are given. As for the transistor control device is a microcontroller Arduino which has a low cost an...

  13. Modelling and characterisation of transistors | Akande | Global ...

    African Journals Online (AJOL)

    Models and characterisation of active devices that control the flow of energy operating within and outside the active region of the operating domain are presented. Specifically, the incremental charge carrier and Ebers Moll models of the bipolar junction transistor are presented and the parameters of electrical behaviour of ...

  14. A transistor based on 2D material and silicon junction

    Science.gov (United States)

    Kim, Sanghoek; Lee, Seunghyun

    2017-07-01

    A new type of graphene-silicon junction transistor based on bipolar charge-carrier injection was designed and investigated. In contrast to many recent studies on graphene field-effect transistor (FET), this device is a new type of bipolar junction transistor (BJT). The transistor fully utilizes the Fermi level tunability of graphene under bias to increase the minority-carrier injection efficiency of the base-emitter junction in the BJT. Single-layer graphene was used to form the emitter and the collector, and a p-type silicon was used as the base. The output of this transistor was compared with a metal-silicon junction transistor ( i.e. surface-barrier transistor) to understand the difference between a graphene-silicon junction and metal-silicon Schottky junction. A significantly higher current gain was observed in the graphene-silicon junction transistor as the base current was increased. The graphene-semiconductor heterojunction transistor offers several unique advantages, such as an extremely thin device profile, a low-temperature (transistor current gain ( β) of 33.7 and a common-emitter amplifier voltage gain of 24.9 were achieved.

  15. The Complete Semiconductor Transistor and Its Incomplete Forms

    Science.gov (United States)

    Binbin, Jie; Chih-Tang, Sah

    2009-06-01

    This paper describes the definition of the complete transistor. For semiconductor devices, the complete transistor is always bipolar, namely, its electrical characteristics contain both electron and hole currents controlled by their spatial charge distributions. Partially complete or incomplete transistors, via coined names or/and designed physical geometries, included the 1949 Shockley p/n junction transistor (later called Bipolar Junction Transistor, BJT), the 1952 Shockley unipolar 'field-effect' transistor (FET, later called the p/n Junction Gate FET or JGFET), as well as the field-effect transistors introduced by later investigators. Similarities between the surface-channel MOS-gate FET (MOSFET) and the volume-channel BJT are illustrated. The bipolar currents, identified by us in a recent nanometer FET with 2-MOS-gates on thin and nearly pure silicon base, led us to the recognition of the physical makeup and electrical current and charge compositions of a complete transistor and its extension to other three or more terminal signal processing devices, and also the importance of the terminal contacts.

  16. In-situ SiN{sub x}/InN structures for InN field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Zervos, Ch., E-mail: hzervos@physics.uoc.gr; Georgakilas, A. [Microelectronics Research Group (MRG), Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas - FORTH, P.O. Box 1385, GR-70013 Heraklion, Crete (Greece); Department of Physics, University of Crete, P.O. Box 2208, GR-71003 Heraklion, Crete (Greece); Adikimenakis, A.; Kostopoulos, A.; Kayambaki, M.; Tsagaraki, K.; Konstantinidis, G. [Microelectronics Research Group (MRG), Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas - FORTH, P.O. Box 1385, GR-70013 Heraklion, Crete (Greece); Beleniotis, P. [Department of Physics, University of Crete, P.O. Box 2208, GR-71003 Heraklion, Crete (Greece)

    2016-04-04

    Critical aspects of InN channel field-effect transistors (FETs) have been investigated. SiN{sub x} dielectric layers were deposited in-situ, in the molecular beam epitaxy system, on the surface of 2 nm InN layers grown on GaN (0001) buffer layers. Metal-insulator-semiconductor Ni/SiN{sub x}/InN capacitors were analyzed by capacitance-voltage (C-V) and current-voltage measurements and were used as gates in InN FET transistors (MISFETs). Comparison of the experimental C-V results with self-consistent Schrödinger-Poisson calculations indicates the presence of a positive charge at the SiN{sub x}/InN interface of Q{sub if} ≈ 4.4 – 4.8 × 10{sup 13 }cm{sup −2}, assuming complete InN strain relaxation. Operation of InN MISFETs was demonstrated, but their performance was limited by a catastrophic breakdown at drain-source voltages above 2.5–3.0 V, the low electron mobility, and high series resistances of the structures.

  17. Enhancement-Mode AlGaN/GaN High Electron Mobility Transistors Using a Nano-Channel Array Structure

    International Nuclear Information System (INIS)

    Liu Sheng-Hou; Cai Yong; Zeng Chun-Hong; Shi Wen-Hua; Zhang Bao-Shun; Gong Ru-Min; Wang Jin-Yan; Wen, Cheng P.; Feng Zhi-Hong; Wang Jing-Jing; Yin Jia-Yun; Qin Hua

    2011-01-01

    A nano-channel array (NCA) structure is applied to realize enhancement-mode (E-mode) AlGaN/GaN high-electron mobility transistors (HEMTs). The fabricated NCA-HEMT, consisting of 1000 channels connected in parallel with a channel width of 64 nm, shows a threshold voltage of 0.15 V and a subthreshold slope of 78 mV/dec, compared to −3.92 V and 99 mV/dec for a conventional HEMT (C-HEMT), respectively Both the NCA-HEMT and C-HEMT show similar gate leakage current, indicating no significant degradation in gate leakage characteristics for the NCA-HEMT. The surrounding-field effect and relieved polarization contribute to the very large positive threshold voltage shift, while the work function difference makes it positive. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  18. Overlapping and Segregating Structural Brain Abnormalities in Twins With Schizophrenia or Bipolar Disorder

    NARCIS (Netherlands)

    Pol, Hilleke E. Hulshoff; van Baal, G. Caroline M.; Schnack, Hugo G.; Brans, Rachel G. H.; van der Schot, Astrid C.; Brouwer, Rachel M.; van Haren, Neeltje E. M.; Lepage, Claude; Collins, D. Louis; Evans, Alan C.; Boomsma, Dorret I.; Nolen, Willem; Kahn, Rene S.

    Context: The nosologic dichotomy between schizophrenia and bipolar disorder (BD) as formulated by Kraepelin is currently being questioned, stimulated by the finding that schizophrenia and BD partly share a common genetic origin. Although both disorders are characterized by changes in brain

  19. Organic transistors fabricated by contact coating at liquid-solid interface for nano-structures

    Directory of Open Access Journals (Sweden)

    Yu-Wen Cheng

    2015-10-01

    Full Text Available A contact coating method is developed to cover the nano-channels with 100 nm or 200 nm diameter and 400 nm depth with a poly(4-vinylphenol (PVP. In such coating the nano-channels faces downwards and its vertical position is controlled by a motor. The surface is first lowered to be in immediate contact with the polyvinylpyrrolidone (PVPY water solution with concentration from 1 to 5 wt%, then pulled at the speed of 0.004 to 0.4 mm/s. By tuning the pulling speed and concentration we can realize conformal, filled, top-only, as well as floating film morphology. For a reproducible liquid detachment from the solid, the sample has a small tilt angle of 3 degree. Contact coating is used to cover the Al grid base of the vertical space-charge-limited transistor with PVPY. Poly(3-hexylthiophene-2,5-diyl (P3HT as the semiconductor. The transistor breakdown voltage is raised due to base coverage achieved by contact coating.

  20. Structural and electrical properties of the europium-doped indium zinc oxide thin film transistors

    International Nuclear Information System (INIS)

    Ting, Chu-Chi; Li, Wei-Yang; Wang, Ching-Hua; Yong, Hua-En

    2014-01-01

    The EuInZnO (EIZO) thin film transistor (TFT) devices were fabricated by the sol–gel spin-coating technique. The EIZO TFT operates in the n-channel depletion mode and exhibits a well-defined pinch-off and saturation region. Because europium ion possesses lower electronegativity (1.2) and standard electrode potential (− 1.991 V), it can act as the carrier suppressor to reduce the carrier concentrations of the IZO (In:Zn = 1:1) thin film. Eu 3+ (13 mol%)-doped IZO TFT possesses the optimum performance, and its field-effect mobility in the saturated regime, threshold voltage, on–off ratio, and S-factor are 1.23 cm 2 /Vs, 3.28 V, 1.07 × 10 6 , and 2.28 V/decade, respectively. - Highlights: • Europium ions can act as the carrier suppressor in the InZnO system. • The EuInZnO forms an n-channel material for the thin film transistor (TFT) device. • The optimum performance of the EuInZnO TFT is the sample with 13 mol% Eu 3+ doping

  1. A light-stimulated synaptic transistor with synaptic plasticity and memory functions based on InGaZnOx–Al2O3 thin film structure

    International Nuclear Information System (INIS)

    Li, H. K.; Chen, T. P.; Liu, P.; Zhang, Q.; Hu, S. G.; Liu, Y.; Lee, P. S.

    2016-01-01

    In this work, a synaptic transistor based on the indium gallium zinc oxide (IGZO)–aluminum oxide (Al 2 O 3 ) thin film structure, which uses ultraviolet (UV) light pulses as the pre-synaptic stimulus, has been demonstrated. The synaptic transistor exhibits the behavior of synaptic plasticity like the paired-pulse facilitation. In addition, it also shows the brain's memory behaviors including the transition from short-term memory to long-term memory and the Ebbinghaus forgetting curve. The synapse-like behavior and memory behaviors of the transistor are due to the trapping and detrapping processes of the holes, which are generated by the UV pulses, at the IGZO/Al 2 O 3 interface and/or in the Al 2 O 3 layer.

  2. A light-stimulated synaptic transistor with synaptic plasticity and memory functions based on InGaZnOx-Al2O3 thin film structure

    Science.gov (United States)

    Li, H. K.; Chen, T. P.; Liu, P.; Hu, S. G.; Liu, Y.; Zhang, Q.; Lee, P. S.

    2016-06-01

    In this work, a synaptic transistor based on the indium gallium zinc oxide (IGZO)-aluminum oxide (Al2O3) thin film structure, which uses ultraviolet (UV) light pulses as the pre-synaptic stimulus, has been demonstrated. The synaptic transistor exhibits the behavior of synaptic plasticity like the paired-pulse facilitation. In addition, it also shows the brain's memory behaviors including the transition from short-term memory to long-term memory and the Ebbinghaus forgetting curve. The synapse-like behavior and memory behaviors of the transistor are due to the trapping and detrapping processes of the holes, which are generated by the UV pulses, at the IGZO/Al2O3 interface and/or in the Al2O3 layer.

  3. Dependence of Internal Crystal Structures of InAs Nanowires on Electrical Characteristics of Field Effect Transistors

    Science.gov (United States)

    Han, Sangmoon; Choi, Ilgyu; Lee, Kwanjae; Lee, Cheul-Ro; Lee, Seoung-Ki; Hwang, Jeongwoo; Chung, Dong Chul; Kim, Jin Soo

    2018-02-01

    We report on the dependence of internal crystal structures on the electrical properties of a catalyst-free and undoped InAs nanowire (NW) formed on a Si(111) substrate by metal-organic chemical vapor deposition. Cross-sectional transmission electron microscopy images, obtained from four different positions of a single InAs NW, indicated that the wurtzite (WZ) structure with stacking faults was observed mostly in the bottom region of the NW. Vertically along the InAs NW, the amount of stacking faults decreased and a zinc-blende (ZB) structure was observed. At the top of the NW, the ZB structure was prominently observed. The resistance and resistivity of the top region of the undoped InAs NW with the ZB structure were measured to be 121.5 kΩ and 0.19 Ω cm, respectively, which are smaller than those of the bottom region with the WZ structure, i.e., 251.8 kΩ and 0.39 Ω cm, respectively. The reduction in the resistance of the top region of the NW is attributed to the improvement in the crystal quality and the change in the ZB crystal structure. For a field effect transistor with an undoped InAs NW channel, the drain current versus drain-source voltage characteristic curves under various negative gate-source voltages were successfully observed at room temperature.

  4. Infrared-transmittance tunable metal-insulator conversion device with thin-film-transistor-type structure on a glass substrate

    Directory of Open Access Journals (Sweden)

    Takayoshi Katase

    2017-05-01

    Full Text Available Infrared (IR transmittance tunable metal-insulator conversion was demonstrated on a glass substrate by using thermochromic vanadium dioxide (VO2 as the active layer in a three-terminal thin-film-transistor-type device with water-infiltrated glass as the gate insulator. Alternative positive/negative gate-voltage applications induce the reversible protonation/deprotonation of a VO2 channel, and two-orders of magnitude modulation of sheet-resistance and 49% modulation of IR-transmittance were simultaneously demonstrated at room temperature by the metal-insulator phase conversion of VO2 in a non-volatile manner. The present device is operable by the room-temperature protonation in an all-solid-state structure, and thus it will provide a new gateway to future energy-saving technology as an advanced smart window.

  5. Structural brain alterations in bipolar disorder II: a combined voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) study.

    Science.gov (United States)

    Ambrosi, Elisa; Rossi-Espagnet, Maria Camilla; Kotzalidis, Georgios D; Comparelli, Anna; Del Casale, Antonio; Carducci, Filippo; Romano, Andrea; Manfredi, Giovanni; Tatarelli, Roberto; Bozzao, Alessandro; Girardi, Paolo

    2013-09-05

    Brain structural changes have been described in bipolar disorder (BP), but usually studies focused on both I and II subtypes indiscriminately and investigated changes in either brain volume or white matter (WM) integrity. We used combined voxel-based morphometry (VBM) and diffusion tensor imaging (DTI) analysis to track changes in the grey matter (GM) and WM in the brains of patients affected by BPII, as compared to healthy controls. Using VBM and DTI, we scanned 20 DSM-IV-TR BPII patients in their euthymic phase and 21 healthy, age- and gender-matched volunteers with no psychiatric history. VBM showed decreases in GM of BPII patients, compared to controls, which were diffuse in nature and most prominent in the right middle frontal gyrus and in the right superior temporal gurus. DTI showed significant and widespread FA reduction in BPII patients in all major WM tracts, including cortico-cortical association tracts. The small sample size limits the generalisability of our findings. Reduced GM volumes and WM integrity changes in BPII patients are not prominent like those previously reported in bipolar disorder type-I and involve cortical structures and their related association tracts. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Various aspects of ionic machining applied to metallic systems in microwave dipolar transistors

    International Nuclear Information System (INIS)

    Pestie, J.P.; Dumontet, H.; Andrieu, J.P.

    1974-01-01

    The positive benefit of ion bombardment machining in fabricating bipolar microwave transistors is shown. Ion cleaning, especially for P type silicon with high boron concentration allows reproducible surface resistivities to be reached 10 -6 ohms/cm 2 ) and the spurious resistance of the basis to be minimized. Ionic etching of metallic layers allowed 1μm stepped geometric structures to be realized. The multilayer Ti-Pt-Au system was associated to the finest geometries through a finite number of operations [fr

  7. Constructing Diodes and Transistors for Ultracold Atoms

    Science.gov (United States)

    Pepino, Ronald; Cooper, John; Anderson, Dana; Holland, Murray

    2008-05-01

    The ultracold atom-optical analogy to electronic systems is presented, along with the master equation formalism that is applied to this novel physical context of system-reservoir interactions. The proposed formalism lends itself quite readily to not only the study of atomtronic systems, but also transport properties of ultracold atoms in optical lattices. We demonstrate how these systems can be configured so that they emulate the behavior of the electronic diode, field effect transistor (FET), and bipolar junction transistor (BJT). The behavior of simple logic gates: namely, the AND and OR gates are follow as direct consequences of the atomtronic BJTs.

  8. 75 GHz InP DHBT power amplifier based on two-stacked transistors

    DEFF Research Database (Denmark)

    Squartecchia, Michele; Midili, Virginio; Johansen, Tom Keinicke

    2017-01-01

    In this paper we present the design and measurements of a two-stage 75-GHz InP Double Heterojunction Bipolar Transistor (DHBT) power amplifier (PA). An optimized two-stacked transistor power cell has been designed, which represents the building block in the power stage as well as in the driver...... stage of the power amplifier. Besides the series voltage addition of the stacked structure, parallel power combining techniques were adopted to increase the output power of the MMIC amplifier, with four-way and eight-way corporate power combiners at the driver and power stages, respectively. At 75 GHz......, the power amplifier exhibits a small signal gain of G = 12.6 dB, output power at 1-dB compression of Pout, 1dB = 18.6 dBm and a saturated output power of Psat > 21.4 dBm....

  9. Irradiation effect on back-gate graphene field-effect transistor

    Science.gov (United States)

    Chen, Xinlu; Srivastava, Ashok; Sharma, Ashwani K.; Mayberry, Clay

    2017-05-01

    The effects of irradiations on MOSFET and bipolar junction transistors are well known though irradiation mechanisms in two-dimensional graphene and related devices are still being investigated. In this work, we investigate irradiation mechanism based on a semi-empirical model for the graphene back-gate transistor and quantitatively analyze the irradiation influences on electrical properties of the device structure. The irradiation shifts the current which changes the region of device operation, degrades the mobility and increases the channel resistance which can increase the power dissipation. The main mechanism causing the degradation in performance of devices is the oxide trap charges near the SiO2/graphene interface and graphene layer traps charges.

  10. Capacitorless one-transistor dynamic random-access memory based on asymmetric double-gate Ge/GaAs-heterojunction tunneling field-effect transistor with n-doped boosting layer and drain-underlap structure

    Science.gov (United States)

    Yoon, Young Jun; Seo, Jae Hwa; Kang, In Man

    2018-04-01

    In this work, we present a capacitorless one-transistor dynamic random-access memory (1T-DRAM) based on an asymmetric double-gate Ge/GaAs-heterojunction tunneling field-effect transistor (TFET) for DRAM applications. The n-doped boosting layer and gate2 drain-underlap structure is employed in the device to obtain an excellent 1T-DRAM performance. The n-doped layer inserted between the source and channel regions improves the sensing margin because of a high rate of increase in the band-to-band tunneling (BTBT) probability. Furthermore, because the gate2 drain-underlap structure reduces the recombination rate that occurs between the gate2 and drain regions, a device with a gate2 drain-underlap length (L G2_D-underlap) of 10 nm exhibited a longer retention performance. As a result, by applying the n-doped layer and gate2 drain-underlap structure, the proposed device exhibited not only a high sensing margin of 1.11 µA/µm but also a long retention time of greater than 100 ms at a temperature of 358 K (85 °C).

  11. Middle Electrode in a Vertical Transistor Structure Using an Sn Layer by Thermal Evaporation

    Science.gov (United States)

    Nogueira, Gabriel Leonardo; da Silva Ozório, Maiza; da Silva, Marcelo Marques; Morais, Rogério Miranda; Alves, Neri

    2018-03-01

    We report a process for performing the middle electrode for a vertical field effect transistor (VOFET) by the evaporation of a tin (Sn) layer. Bare aluminum oxide (Al2O3), obtained by anodization, and Al2O3 covered with a polymethylmethacrylate (PMMA) layer were used as the gate dielectric. We measured the electrical resistance of Sn while the evaporation was carried out to find the best condition to prepare the middle electrode, that is, good lateral conduction associated with openings that give permeability to the electric field in a vertical direction. This process showed that 55 nm Sn thick is suitable for use in a VOFET, being easier to achieve optimal thickness when the Sn is evaporated onto PMMA than onto bare Al2O3. The addition of a PMMA layer on the Al2O3 surface modifies the morphology of the Sn layer, resulting in a lowering of the threshold voltage. The values of threshold voltage and electric field, VTH = - 8 V and ETH = 354.5 MV/m respectively, were calculated using an Al2O3 film 20 nm thick covered with a 14 nm PMMA layer as gate dielectric, while for bare Al2O3 these values were VTH = - 10 V and ETH = 500 MV/m.

  12. A forming-free bipolar resistive switching behavior based on ITO/V2O5/ITO structure

    Science.gov (United States)

    Wan, Zhenni; Darling, Robert B.; Majumdar, Arka; Anantram, M. P.

    2017-07-01

    Forming-free bipolar resistive switching behavior in an ITO/V2O5/ITO structure is observed. While the bottom ITO layer functions as a common ground electrode, the top ITO layer is an active element and used as an oxygen reservoir, with an additional metal electrode patterned on its top for making contact. In contrast to typical metal/transition metal oxide/metal based resistive memories, our device exhibits a low resistance state in its virgin state and is switched to a high resistance state when a forward bias of ˜+2.5 V is applied. The device can be reset to its original state at a reverse bias of ˜-1.5 V. A noticeable decrease in switching voltage with a reduced top contact area is observed, indicating a strong electric field enhanced switching mechanism. Different from the widely seen conductive filament mechanism in bipolar switching, we explain the switching behavior by the migration of oxygen ions at the top ITO/V2O5 interface. When oxygen ions are extracted to the ITO side, an interfacial layer with reduced oxidation states is formed and acts as a Schottky barrier that suppresses the current through the whole device. The results suggest future applications in low power, high speed integrated non-volatile memories.

  13. Modelling ionising radiation induced defect generation in bipolar oxides with gated diodes

    International Nuclear Information System (INIS)

    Barnaby, H.J.; Cirba, C.; Schrimpf, R.D.; Kosier, St.; Fouillat, P.; Montagner, X.

    1999-01-01

    Radiation-induced oxide defects that degrade electrical characteristics of bipolar junction transistor (BJTs) can be measured with the use of gated diodes. The buildup of defects and their effect on device radiation response are modeled with computer simulation. (authors)

  14. Simulation of a Novel Bipolar-FET Type-S, Negative Resistance Circuit

    Directory of Open Access Journals (Sweden)

    Umesh Kumar

    2003-01-01

    Full Text Available A new circuit which uses FET and bipolar transistor is given. It exhibits Type-S differential negative resistance and a theoretical explanation is appended along with PSPICE simulation.

  15. Fast turn-on of an NMOS ESD protection transistor: measurements and simulations

    NARCIS (Netherlands)

    Luchies, J.R.M.; Luchies, J.R.M.; de Kort, C.G.M.; Verweij, J.F.; Verweij, J.F.

    1995-01-01

    The transient turn-on of the parasitic bipolar transistor of an NMOS transistor was studied. The voltages appearing at internal nodes of protection and functional circuit after application of 350 ps rise-time pulses have been measured using electro-optic sampling. For very fast transients the

  16. Structural brain abnormalities in patients with type I bipolar disorder and suicidal behavior.

    Science.gov (United States)

    Duarte, Dante G G; Neves, Maila de Castro L; Albuquerque, Maicon R; Turecki, Gustavo; Ding, Yang; de Souza-Duran, Fabio Luis; Busatto, Geraldo; Correa, Humberto

    2017-07-30

    Some studies have identified brain morphological changes in the frontolimbic network (FLN) in bipolar subjects who attempt suicide (SA). The present study investigated neuroanatomical abnormalities in the FLN to find a possible neural signature for suicidal behavior in patients with bipolar disorder type I (BD-I). We used voxel-based morphometry to compare euthymic patients with BD-I who had attempted suicide (n=20), who had not attempted suicide (n=19) and healthy controls (HCs) (n=20). We also assessed the highest medical lethality of their previous SA. Compared to the participants who had not attempted suicide, the patients with BD-I who had attempted suicide exhibited significantly increased gray matter volume (GMV) in the right rostral anterior cingulate cortex (ACC), which was more pronounced and extended further to the left ACC in the high-lethality subgroup (p<0.05, with family-wise error (FWE) correction for multiple comparisons using small-volume correction). GMV in the insula and orbitofrontal cortex was also related to suicide lethality (p<0.05, FWE-corrected). The current findings suggest that morphological changes in the FLN could be a signature of previous etiopathogenic processes affecting regions related to suicidality and its severity in BD-I patients. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  17. Bipolar disorder

    Science.gov (United States)

    ... of pleasure in activities once enjoyed Loss of self-esteem Thoughts of death or suicide Trouble getting to ... other. This is called rapid cycling. Exams and Tests To diagnose bipolar disorder, the provider may do ...

  18. Bipolar disorder

    Directory of Open Access Journals (Sweden)

    F Colin

    2013-08-01

    Full Text Available Bipolar disorder (BD presents in different phases over time and is oftencomplicated by comorbid conditions such as substance-use disordersand anxiety disorders. Treatment usually involves pharmacotherapywith combinations of different classes of medications and frequentmedication revisions.

  19. Assessment of pseudo-bilayer structures in the heterogate germanium electron-hole bilayer tunnel field-effect transistor

    Energy Technology Data Exchange (ETDEWEB)

    Padilla, J. L., E-mail: jose.padilladelatorre@epfl.ch; Alper, C.; Ionescu, A. M. [Nanoelectronic Devices Laboratory, École Polytechnique Fédérale de Lausanne, Lausanne CH-1015 (Switzerland); Medina-Bailón, C.; Gámiz, F. [Departamento de Electrónica y Tecnología de los Computadores, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada (Spain)

    2015-06-29

    We investigate the effect of pseudo-bilayer configurations at low operating voltages (≤0.5 V) in the heterogate germanium electron-hole bilayer tunnel field-effect transistor (HG-EHBTFET) compared to the traditional bilayer structures of EHBTFETs arising from semiclassical simulations where the inversion layers for electrons and holes featured very symmetric profiles with similar concentration levels at the ON-state. Pseudo-bilayer layouts are attained by inducing a certain asymmetry between the top and the bottom gates so that even though the hole inversion layer is formed at the bottom of the channel, the top gate voltage remains below the required value to trigger the formation of the inversion layer for electrons. Resulting benefits from this setup are improved electrostatic control on the channel, enhanced gate-to-gate efficiency, and higher I{sub ON} levels. Furthermore, pseudo-bilayer configurations alleviate the difficulties derived from confining very high opposite carrier concentrations in very thin structures.

  20. Performance improvement inpolymer-based thin film transistor using modified bottom-contact structures with etched SiO{sub 2} layers

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong Woo [R and D Center, Samsung Corning Precision Materials Co., Ltd, Asan (Korea, Republic of); You, Young Jun; Shim, Jae Won [Dept. of Electronics and Electrical Engineering, Dongguk University-Seoul, Seoul (Korea, Republic of)

    2017-02-15

    Polymer-based thin film transistors (TFTs) with a modified bottom-contact structure and etched SiO{sub 2} layer were developed and investigated. An increase in the field-effect mobility in the developed TFTs compared to TFTs with a normal bottom-contact structure was ascertained. A bottom-contact structure and the photolithographic processing method were used to ensure that the developed TFTs were suitable for commercial applications. Increased mobility of the modified bottom-contact structure was attributed to direct contact of the Au electrode with the active polymer layer.

  1. CENP-W plays a role in maintaining bipolar spindle structure.

    Directory of Open Access Journals (Sweden)

    Agnieszka Kaczmarczyk

    Full Text Available The CENP-W/T complex was previously reported to be required for mitosis. HeLa cells depleted of CENP-W displayed profound mitotic defects, with mitotic timing delay, disorganized prometaphases and multipolar spindles as major phenotypic consequences. In this study, we examined the process of multipolar spindle formation induced by CENP-W depletion. Depletion of CENP-W in HeLa cells labeled with histone H2B and tubulin fluorescent proteins induced rapid fragmentation of originally bipolar spindles in a high proportion of cells. CENP-W depletion was associated with depletion of Hec1 at kinetochores. The possibility of promiscuous centrosomal duplication was ruled out by immunofluorescent examination of centrioles. However, centrioles were frequently observed to be abnormally split. In addition, a large proportion of the supernumerary poles lacked centrioles, but were positively stained with different centrosomal markers. These observations suggested that perturbation in spindle force distribution caused by defective kinetochores could contribute to a mechanical mechanism for spindle pole disruption. 'Spindle free' nocodazole arrested cells did not exhibit pole fragmentation after CENP-W depletion, showing that pole fragmentation is microtubule dependent. Inhibition of centrosome separation by monastrol reduced the incidence of spindle pole fragmentation, indicating that Eg5 plays a role in spindle pole disruption. Surprisingly, CENP-W depletion rescued the monopolar spindle phenotype of monastrol treatment, with an increased frequency of bipolar spindles observed after CENP-W RNAi. We overexpressed the microtubule cross-linking protein TPX2 to create spindle poles stabilized by the microtubule cross-linking activity of TPX2. Spindle pole fragmentation was suppressed in a TPX2-dependent fashion. We propose that CENP-W, by influencing proper kinetochore assembly, particularly microtubule docking sites, can confer spindle pole resistance to traction

  2. Coaxial-structured ZnO/silicon nanowires extended-gate field-effect transistor as pH sensor

    International Nuclear Information System (INIS)

    Li, Hung-Hsien; Yang, Chi-En; Kei, Chi-Chung; Su, Chung-Yi; Dai, Wei-Syuan; Tseng, Jung-Kuei; Yang, Po-Yu; Chou, Jung-Chuan; Cheng, Huang-Chung

    2013-01-01

    An extended-gate field-effect transistor (EGFET) of coaxial-structured ZnO/silicon nanowires as pH sensor was demonstrated in this paper. The oriented 1-μm-long silicon nanowires with the diameter of about 50 nm were vertically synthesized by the electroless metal deposition method at room temperature and were sequentially capped with the ZnO films using atomic layer deposition at 50 °C. The transfer characteristics (I DS –V REF ) of such ZnO/silicon nanowire EGFET sensor exhibited the sensitivity and linearity of 46.25 mV/pH and 0.9902, respectively for the different pH solutions (pH 1–pH 13). In contrast to the ZnO thin-film ones, the ZnO/silicon nanowire EGFET sensor achieved much better sensitivity and superior linearity. It was attributed to a high surface-to-volume ratio of the nanowire structures, reflecting a larger effective sensing area. The output voltage and time characteristics were also measured to indicate good reliability and durability for the ZnO/silicon nanowires sensor. Furthermore, the hysteresis was 9.74 mV after the solution was changed as pH 7 → pH 3 → pH 7 → pH 11 → pH 7. - Highlights: ► Coaxial-structured ZnO/silicon nanowire EGFET was demonstrated as pH sensor. ► EMD and ALD methods were proposed to fabricate ZnO/silicon nanowires. ► ZnO/silicon nanowire EGFET sensor achieved better sensitivity and linearity. ► ZnO/silicon nanowire EGFET sensor had good reliability and durability

  3. Transistor Small Signal Analysis under Radiation Effects

    International Nuclear Information System (INIS)

    Sharshar, K.A.A.

    2004-01-01

    A Small signal transistor parameters dedicate the operation of bipolar transistor before and after exposed to gamma radiation (1 Mrad up to 5 Mrads) and electron beam(1 MeV, 25 mA) with the same doses as a radiation sources, the electrical parameters of the device are changed. The circuit Model has been discussed.Parameters, such as internal emitter resistance (re), internal base resistance, internal collector resistance (re), emitter base photocurrent (Ippe) and base collector photocurrent (Ippe). These parameters affect on the operation of the device in its applications, which work as an effective element, such as current gain (hFE≡β)degradation it's and effective parameter in the device operation. Also the leakage currents (IcBO) and (IEBO) are most important parameters, Which increased with radiation doses. Theoretical representation of the change in the equivalent circuit for NPN and PNP bipolar transistor were discussed, the input and output parameters of the two types were discussed due to the change in small signal input resistance of the two types. The emitter resistance(re) were changed by the effect of gamma and electron beam irradiation, which makes a change in the role of matching impedances between transistor stages. Also the transistor stability factors S(Ico), S(VBE) and S(β are detected to indicate the transistor operations after exposed to radiation fields. In low doses the gain stability is modified due to recombination of induced charge generated during device fabrication. Also the load resistance values are connected to compensate the effect

  4. High current transistor pulse generator

    Science.gov (United States)

    Nesterov, V.; Cassel, R.

    1991-05-01

    A solid state pulse generator capable of delivering high current trapezoidally shaped pulses into an inductive load has been developed at SLAC. Energy stored in the capacitor bank of the pulse generator is switched to the load through a pair of Darlington transistors. A combination of diodes and Darlington transistors is used to obtain trapezoidal or triangular shaped current pulses into an inductive load and to recover the remaining energy in the same capacitor bank without reversing capacitor voltage. The transistors work in the switch mode, and the power losses are low. The rack mounted pulse generators presently used at SLAC contain a 660 microfarad storage capacitor bank and can deliver 400 amps at 800 volts into inductive loads up to 3 mH. The pulse generators are used in several different power systems, including pulse to pulse bipolar power supplies and in application with current pulses distributed into different inductive loads. The current amplitude and discharge time are controlled by the central computer system through a specially developed multichannel controller. Several years of operation with the pulse generators have proven their consistent performance and reliability.

  5. High current transistor pulse generator

    International Nuclear Information System (INIS)

    Nesterov, V.; Cassel, R.

    1991-05-01

    A solid state pulse generator capable of delivering high current trapezoidally shaped pulses into an inductive load has been developed at SLAC. Energy stored in the capacitor bank of the pulse generator is switched to the load through a pair of Darlington transistors. A combination of diodes and Darlington transistors is used to obtain trapezoidal or triangular shaped current pulses into an inductive load and to recover the remaining energy in the same capacitor bank without reversing capacitor voltage. The transistors work in the switch mode, and the power losses are low. The rack mounted pulse generators presently used at SLAC contain a 660 microfarad storage capacitor bank and can deliver 400 amps at 800 volts into inductive loads up to 3 mH. The pulse generators are used in several different power systems, including pulse to pulse bipolar power supplies and in application with current pulses distributed into different inductive loads. The current amplitude and discharge time are controlled by the central computer system through a specially developed multichannel controller. Several years of operation with the pulse generators have proven their consistent performance and reliability. 8 figs

  6. Crystal structure of the HSV-1 Fc receptor bound to Fc reveals a mechanism for antibody bipolar bridging.

    Directory of Open Access Journals (Sweden)

    Elizabeth R Sprague

    2006-06-01

    Full Text Available Herpes simplex virus type-1 expresses a heterodimeric Fc receptor, gE-gI, on the surfaces of virions and infected cells that binds the Fc region of host immunoglobulin G and is implicated in the cell-to-cell spread of virus. gE-gI binds immunoglobulin G at the basic pH of the cell surface and releases it at the acidic pH of lysosomes, consistent with a role in facilitating the degradation of antiviral antibodies. Here we identify the C-terminal domain of the gE ectodomain (CgE as the minimal Fc-binding domain and present a 1.78-angstroms CgE structure. A 5-angstroms gE-gI/Fc crystal structure, which was independently verified by a theoretical prediction method, reveals that CgE binds Fc at the C(H2-C(H3 interface, the binding site for several mammalian and bacterial Fc-binding proteins. The structure identifies interface histidines that may confer pH-dependent binding and regions of CgE implicated in cell-to-cell spread of virus. The ternary organization of the gE-gI/Fc complex is compatible with antibody bipolar bridging, which can interfere with the antiviral immune response.

  7. Structural dysconnectivity of key cognitive and emotional hubs in young people at high genetic risk for bipolar disorder.

    Science.gov (United States)

    Roberts, G; Perry, A; Lord, A; Frankland, A; Leung, V; Holmes-Preston, E; Levy, F; Lenroot, R K; Mitchell, P B; Breakspear, M

    2018-02-01

    Emerging evidence suggests that psychiatric disorders are associated with disturbances in structural brain networks. Little is known, however, about brain networks in those at high risk (HR) of bipolar disorder (BD), with such disturbances carrying substantial predictive and etiological value. Whole-brain tractography was performed on diffusion-weighted images acquired from 84 unaffected HR individuals with at least one first-degree relative with BD, 38 young patients with BD and 96 matched controls (CNs) with no family history of mental illness. We studied structural connectivity differences between these groups, with a focus on highly connected hubs and networks involving emotional centres. HR participants showed lower structural connectivity in two lateralised sub-networks centred on bilateral inferior frontal gyri and left insular cortex, as well as increased connectivity in a right lateralised limbic sub-network compared with CN subjects. BD was associated with weaker connectivity in a small right-sided sub-network involving connections between fronto-temporal and temporal areas. Although these sub-networks preferentially involved structural hubs, the integrity of the highly connected structural backbone was preserved in both groups. Weaker structural brain networks involving key emotional centres occur in young people at genetic risk of BD and those with established BD. In contrast to other psychiatric disorders such as schizophrenia, the structural core of the brain remains intact, despite the local involvement of network hubs. These results add to our understanding of the neurobiological correlates of BD and provide predictions for outcomes in young people at high genetic risk for BD.

  8. Test Equipment Specifications Transistor

    OpenAIRE

    Didiek Andiana Ramadan; Drs. Linga Hermanto, MMSI Drs. Linga Hermanto, MMSI

    2005-01-01

    In this paper, we design a test apparatus Transistor Specification. Specification is atype of transistor is a transistor and common emitter current reinforcement value ( βDC ). The system will provide information in the form of an LED display emits greenlight when the tested types of NPN transistor and the second LED emits blue lightwhen the tested types of PNP transistors.To test the value of β, whose value is proportional to the display used by the collectorcurrent Ic.

  9. Nanowire Field-Effect Transistors : Sensing Simplicity?

    NARCIS (Netherlands)

    Mescher, M.

    2014-01-01

    Silicon nanowires are structures made from silicon with at least one spatial dimension in the nanometer regime (1-100 nm). From these nanowires, silicon nanowire field-effect transistors can be constructed. Since their introduction in 2001 silicon nanowire field-effect transistors have been studied

  10. Examination of the predictive value of structural magnetic resonance scans in bipolar disorder: a pattern classification approach.

    Science.gov (United States)

    Rocha-Rego, V; Jogia, J; Marquand, A F; Mourao-Miranda, J; Simmons, A; Frangou, S

    2014-02-01

    Bipolar disorder (BD) is one of the leading causes of disability worldwide. Patients are further disadvantaged by delays in accurate diagnosis ranging between 5 and 10 years. We applied Gaussian process classifiers (GPCs) to structural magnetic resonance imaging (sMRI) data to evaluate the feasibility of using pattern recognition techniques for the diagnostic classification of patients with BD. GPCs were applied to gray (GM) and white matter (WM) sMRI data derived from two independent samples of patients with BD (cohort 1: n = 26; cohort 2: n = 14). Within each cohort patients were matched on age, sex and IQ to an equal number of healthy controls. The diagnostic accuracy of the GPC for GM was 73% in cohort 1 and 72% in cohort 2; the sensitivity and specificity of the GM classification were respectively 69% and 77% in cohort 1 and 64% and 99% in cohort 2. The diagnostic accuracy of the GPC for WM was 69% in cohort 1 and 78% in cohort 2; the sensitivity and specificity of the WM classification were both 69% in cohort 1 and 71% and 86% respectively in cohort 2. In both samples, GM and WM clusters discriminating between patients and controls were localized within cortical and subcortical structures implicated in BD. Our results demonstrate the predictive value of neuroanatomical data in discriminating patients with BD from healthy individuals. The overlap between discriminative networks and regions implicated in the pathophysiology of BD supports the biological plausibility of the classifiers.

  11. Effects of ankyrin 3 gene risk variants on brain structures in patients with bipolar disorder and healthy subjects.

    Science.gov (United States)

    Ota, Miho; Hori, Hiroaki; Sato, Noriko; Yoshida, Fuyuko; Hattori, Kotaro; Teraishi, Toshiya; Kunugi, Hiroshi

    2016-11-01

    The intronic single-nucleotide polymorphism rs10994336 of the ankyrin 3 gene (ANK3 ) is one of the genome-wide supported risk variants for bipolar disorder (BD), and the T-allele of rs10761482 is also reported to have relevance to BD. We investigated the effect of ANK3 rs10761482 genetic variation on brain structure. Subjects were 43 BD patients and 229 healthy volunteers. We evaluated the effects of ANK3 rs10761482 genetic variation on diagnosis, and of the genotype-by-diagnosis interaction on the brain structure and the degree of age-related brain atrophy on magnetic resonance imaging data evaluated by voxel-based morphometry. BD patients showed significantly lower fractional anisotropy value in the bilateral parietal regions, left fronto-occipital fasciculus, and corpus callosum, compared to healthy subjects. Further, we found considerable decreases of fractional anisotropy in the forceps minor in non-T-allele BD patients compared with the T-carrier patient group. We also found significant lessening of age-related brain atrophy in the T-allele carrier groups compared with the non-T-allele carrier groups in the area around the cerebrospinal space, cingulate cortices, and cerebellum. Our results suggest the influence of the ANK3 on age-related brain atrophy. The ankyrin 3 genotype may be associated with pathogenesis of age-related neurodegeneration, and, in part, of BD. © 2016 The Authors. Psychiatry and Clinical Neurosciences © 2016 Japanese Society of Psychiatry and Neurology.

  12. High Accuracy Transistor Compact Model Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Hembree, Charles E. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Mar, Alan [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Robertson, Perry J. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    Typically, transistors are modeled by the application of calibrated nominal and range models. These models consists of differing parameter values that describe the location and the upper and lower limits of a distribution of some transistor characteristic such as current capacity. Correspond- ingly, when using this approach, high degrees of accuracy of the transistor models are not expected since the set of models is a surrogate for a statistical description of the devices. The use of these types of models describes expected performances considering the extremes of process or transistor deviations. In contrast, circuits that have very stringent accuracy requirements require modeling techniques with higher accuracy. Since these accurate models have low error in transistor descriptions, these models can be used to describe part to part variations as well as an accurate description of a single circuit instance. Thus, models that meet these stipulations also enable the calculation of quantifi- cation of margins with respect to a functional threshold and uncertainties in these margins. Given this need, new model high accuracy calibration techniques for bipolar junction transis- tors have been developed and are described in this report.

  13. Bipolar Disorder (For Teens)

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Bipolar Disorder KidsHealth / For Teens / Bipolar Disorder What's in this ... Disorder Print en español Trastorno bipolar What Is Bipolar Disorder? Bipolar disorders are one of several medical conditions ...

  14. An accurate simulation study on capacitance-voltage characteristics of metal-oxide-semiconductor field-effect transistors in novel structures

    Science.gov (United States)

    Yu, Eunseon; Cho, Seongjae; Park, Byung-Gook

    2017-09-01

    An essential and important method for physical and electrical characterization of a metal-oxide-semiconductor (MOS) structure is the capacitance-voltage (C-V) measurement. Judging from the C-V characteristics of a MOS structure, we are allowed to predict the DC and AC behaviors of the field-effect transistor and extract a set of primary parameters. The MOS field-effect transistor (MOSFET) technology has evolved to enhance the gate controllability over the channel in order for effectively suppressing the short-channel effects (SCEs) unwantedly taking place as device scaling progresses. For the goal, numerous novel structures have been suggested for the advanced MOSFET devices. However, the C-V characteristics of such novel MOS structures have not been seldom studied in depth. In this work, we report the C-V characteristics of ultra-thin-body (UTB) MOSFETs on the bulk Si and silicon-on-insulator (SOI) substrates by rigorous technology computer-aided design (TCAD) simulation. For higher credibility and accuracy, quantum-mechanical models are activated and empirical material parameters are employed from the existing literature. The MOSFET structure and the material configurations are schemed referring advanced logic technology suggested by the most recent technology roadmap. The C-V characteristics of UTB MOSFETs having a floating body with extremely small volume are closely investigated.

  15. Radiation tolerance of NPN bipolar technology with 30 GHz Ft

    International Nuclear Information System (INIS)

    Flament, O.; Synold, S.; Pontcharra, J. de; Niel, S.

    1999-01-01

    The ionizing dose and neutron radiation tolerance of Si QSA bipolar technology has been investigated. The transistors exhibit good radiation tolerance up to 100 krad and 5 10 13 n/cm 2 without any special fabrication steps to harden the technology to the studied effects. (authors)

  16. Inkjet-printed silver nanoparticles on nano-engineered cellulose films for electrically conducting structures and organic transistors: concept and challenges

    Science.gov (United States)

    Chinga-Carrasco, Gary; Tobjörk, Daniel; Österbacka, Ronald

    2012-11-01

    This study explores the suitability of microfibrillated cellulose (MFC) films as a substrate for printing electrically conductive structures and multilayer electronic structures such as organic field effect transistors. Various MFC qualities were tested, including mechanically produced MFC, 2,2,6,6-tetramethylpiperidinyl-1-oxyl pre-treated MFC and carboxymethylated-MFC. The films differed significantly with respect to the surface structure. In addition, the carboxymethylated-MFC films were surface modified with hexamethyldisilazane (HMDS) to reduce the water-wettability of the films, and thus, improve the print resolution of the inkjet-printed silver (Ag) nanoparticles. The Ag-particles (diameter < 50 nm) were printed on the HMDS-modified films, which were mainly composed of nanofibrils with diameters <20 nm. The effect of surface roughness and surface chemical characteristics on the ink spreading and print resolution of the Ag-structures was explored. It was demonstrated that organic transistors operating at low voltages can be fabricated on nano-engineered MFC films.

  17. Inkjet-printed silver nanoparticles on nano-engineered cellulose films for electrically conducting structures and organic transistors: concept and challenges

    Energy Technology Data Exchange (ETDEWEB)

    Chinga-Carrasco, Gary, E-mail: gary.chinga.carrasco@pfi.no [Paper and Fibre Research Institute (PFI) (Norway); Tobjoerk, Daniel; Oesterbacka, Ronald [Abo Akademi University, Physics, Department of Natural Sciences and Center for Functional Materials (Finland)

    2012-11-15

    This study explores the suitability of microfibrillated cellulose (MFC) films as a substrate for printing electrically conductive structures and multilayer electronic structures such as organic field effect transistors. Various MFC qualities were tested, including mechanically produced MFC, 2,2,6,6-tetramethylpiperidinyl-1-oxyl pre-treated MFC and carboxymethylated-MFC. The films differed significantly with respect to the surface structure. In addition, the carboxymethylated-MFC films were surface modified with hexamethyldisilazane (HMDS) to reduce the water-wettability of the films, and thus, improve the print resolution of the inkjet-printed silver (Ag) nanoparticles. The Ag-particles (diameter < 50 nm) were printed on the HMDS-modified films, which were mainly composed of nanofibrils with diameters <20 nm. The effect of surface roughness and surface chemical characteristics on the ink spreading and print resolution of the Ag-structures was explored. It was demonstrated that organic transistors operating at low voltages can be fabricated on nano-engineered MFC films.

  18. What is Bipolar Disorder?

    Science.gov (United States)

    ... affect friends and family? For More Information Share Bipolar Disorder Download PDF Download ePub Order a free hardcopy ... brochure will give you more information. What is bipolar disorder? Bipolar disorder is a serious brain illness. It ...

  19. Structural correlates of creative thinking in patients with bipolar disorder and healthy controls-a voxel-based morphometry study.

    Science.gov (United States)

    Tu, Pei-Chi; Kuan, Yi-Hsuan; Li, Cheng-Ta; Su, Tung-Ping

    2017-06-01

    This study investigated the structural correlates of creative thinking in patients with bipolar disorder (BD) to understand the possible neural mechanism of creative thinking in BD. We recruited 59 patients with BD I or BD II (35.3±8.5 y) and 56 age- and sex-matched controls (HCs; 34±7.4 y). Each participant underwent structural magnetic resonance imaging and evaluation of creative thinking, which was assessed using two validated tools: the Chinese version of the Abbreviated Torrance Test for Adults for divergent thinking and the Chinese Word Remote Associates Test for remote association. Voxel-based morphometry was performed using SPM12. In patients with BD, divergent thinking positively correlated with the gray matter volume (GMV) in right medial frontal gyrus (Brodmann area [BA] 9), and remote association positively correlated with the GMV in the medial prefrontal gyrus (BA 10). In the HCs, divergent thinking negatively correlated with the GMV in left superior frontal gyrus (BA 8) and positively correlated with the GMV in the precuneus and occipital regions, and remote association positively correlated with the GMV in the hippocampus. Patients with BD were receiving various dosages of antipsychotics, antidepressants and mood stabilizer. These medications may confound the GMV-creative thinking relationship in patients with BD. Our findings indicate that medial prefrontal cortex plays a major and positive role in creative thinking in patients with BD. By contrary, creative thinking involves more diverse structures, and the prefrontal cortex may have an opposite effect in HCs. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Multimodal assessments of the hippocampal formation in schizophrenia and bipolar disorder: Evidences from neurobehavioral measures and functional and structural MRI

    Directory of Open Access Journals (Sweden)

    Christian Knöchel

    2014-01-01

    Full Text Available A potential clinical and etiological overlap between schizophrenia (SZ and bipolar disorder (BD has long been a subject of discussion. Imaging studies imply functional and structural alterations of the hippocampus in both diseases. Thus, imaging this core memory region could provide insight into the pathophysiology of these disorders and the associated cognitive deficits. To examine possible shared alterations in the hippocampus, we conducted a multi-modal assessment, including functional and structural imaging as well as neurobehavioral measures of memory performance in BD and SZ patients compared with healthy controls. We assessed episodic memory performance, using tests of verbal and visual learning (HVLT, BVMT in three groups of participants: BD patients (n = 21, SZ patients (n = 21 and matched (age, gender, education healthy control subjects (n = 21. In addition, we examined hippocampal resting state functional connectivity, hippocampal volume using voxel-based morphometry (VBM and fibre integrity of hippocampal connections using diffusion tensor imaging (DTI. We found memory deficits, changes in functional connectivity within the hippocampal network as well as volumetric reductions and altered white matter fibre integrity across patient groups in comparison with controls. However, SZ patients when directly compared with BD patients were more severely affected in several of the assessed parameters (verbal learning, left hippocampal volumes, mean diffusivity of bilateral cingulum and right uncinated fasciculus. The results of our study suggest a graded expression of verbal learning deficits accompanied by structural alterations within the hippocampus in BD patients and SZ patients, with SZ patients being more strongly affected. Our findings imply that these two disorders may share some common pathophysiological mechanisms. The results could thus help to further advance and integrate current pathophysiological models of SZ and BD.

  1. Transtorno bipolar

    Directory of Open Access Journals (Sweden)

    Alda Martin

    1999-01-01

    Full Text Available Os resultados de estudos de famílias sugerem que o transtorno bipolar tenha uma base genética. Essa hipótese foi reforçada em estudos de adoção e de gêmeos. A herança do transtorno bipolar é complexa, envolve vários genes, além de apresentar heterogeneidade e interação entre fatores genéticos e não-genéticos. Achados, que já foram replicados, já implicaram os cromossomos 4, 12, 18 e 21, entre outros, na busca por genes de suscetibilidade. Os resultados mais promissores foram obtidos através de estudos de ligação. Por outro lado, os estudos de associação geraram dados interessantes, mas ainda vagos. Os estudos de populações de pacientes homogêneos e a melhor definição do fenótipo deverão contribuir para avanços futuros. A identificação dos genes relacionados ao transtorno bipolar irá permitir o melhor entendimento e tratamento dessa doença.

  2. Parasitic bipolar amplification in a single event transient and its temperature dependence

    International Nuclear Information System (INIS)

    Liu Zheng; Chen Shu-Ming; Chen Jian-Jun; Qin Jun-Rui; Liu Rong-Rong

    2012-01-01

    Using three-dimensional technology computer-aided design (TCAD) simulation, parasitic bipolar amplification in a single event transient (SET) current of a single transistor and its temperature dependence are studied. We quantify the contributions of different current components in a SET current pulse, and it is found that the proportion of parasitic bipolar amplification in total collected charge is about 30% in both 130-nm and 90-nm technologies. The temperature dependence of parasitic bipolar amplification and the mechanism of the SET pulse are also investigated and quantified. The results show that the proportion of charge induced by parasitic bipolar increases with rising temperature, which illustrates that the parasitic bipolar amplification plays an important role in the charge collection of a single transistor

  3. Theoretical and experimental studies of the current–voltage and capacitance–voltage of HEMT structures and field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Tarasova, E. A.; Obolenskaya, E. S., E-mail: obolensk@rf.unn.ru; Hananova, A. V.; Obolensky, S. V. [Lobachevsky State University of Nizhny Novgorod (NNSU) (Russian Federation); Zemliakov, V. E.; Egorkin, V. I. [National Research University of Electronic Technology (MIET) (Russian Federation); Nezhenzev, A. V. [Lobachevsky State University of Nizhny Novgorod (NNSU) (Russian Federation); Saharov, A. V.; Zazul’nokov, A. F.; Lundin, V. V.; Zavarin, E. E. [Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation); Medvedev, G. V. [JSC RPE Salut (Russian Federation)

    2016-12-15

    The sensitivity of classical n{sup +}/n{sup –} GaAs and AlGaN/GaN structures with a 2D electron gas (HEMT) and field-effect transistors based on these structures to γ-neutron exposure is studied. The levels of their radiation hardness were determined. A method for experimental study of the structures on the basis of a differential analysis of their current–voltage characteristics is developed. This method makes it possible to determine the structure of the layers in which radiation-induced defects accumulate. A procedure taking into account changes in the plate area of the experimentally measured barrier-contact capacitance associated with the emergence of clusters of radiation-induced defects that form dielectric inclusions in the 2D-electron-gas layer is presented for the first time.

  4. Theoretical and experimental studies of the current–voltage and capacitance–voltage of HEMT structures and field-effect transistors

    International Nuclear Information System (INIS)

    Tarasova, E. A.; Obolenskaya, E. S.; Hananova, A. V.; Obolensky, S. V.; Zemliakov, V. E.; Egorkin, V. I.; Nezhenzev, A. V.; Saharov, A. V.; Zazul’nokov, A. F.; Lundin, V. V.; Zavarin, E. E.; Medvedev, G. V.

    2016-01-01

    The sensitivity of classical n + /n – GaAs and AlGaN/GaN structures with a 2D electron gas (HEMT) and field-effect transistors based on these structures to γ-neutron exposure is studied. The levels of their radiation hardness were determined. A method for experimental study of the structures on the basis of a differential analysis of their current–voltage characteristics is developed. This method makes it possible to determine the structure of the layers in which radiation-induced defects accumulate. A procedure taking into account changes in the plate area of the experimentally measured barrier-contact capacitance associated with the emergence of clusters of radiation-induced defects that form dielectric inclusions in the 2D-electron-gas layer is presented for the first time.

  5. Discrete transistor measuring and matching using a solid core oven.

    Science.gov (United States)

    Inkinen, M; Mäkelä, K; Vuorela, T; Palovuori, K

    2013-03-01

    This paper presents transistor measurements done at a constant temperature. The aim in this research was to develop a reliable and repeatable method for measuring and searching transistor pairs with similar parameters, as in certain applications it is advantageous to use transistors from the same production batch due to the significant variability in batches from different manufacturers. Transistor manufacturing methods are well established, but due to the large variability in tolerance, not even transistors from the same manufacturing batch have identical properties. Transistors' electrical properties are also strongly temperature-dependent. Therefore, when measuring transistor properties, the temperature must be kept constant. For the measurement process, a solid-core oven providing stable temperature was implemented. In the oven, the base-to-emitter voltage (VBE) and DC-current gain (β) of 32 transistors could be measured simultaneously. The oven's temperature was controlled with a programmable thermostat, which allowed accurate constant temperature operation. The oven is formed by a large metal block with an individual chamber for each transistor to be measured. Isolation of individual transistors and the highly thermally conductive metal core structure prevent thermal coupling between transistors. The oven enables repeatable measurements, and thus measurements between different batches are comparable. In this research study, the properties of over 5000 transistors were measured and the variance of the aforementioned properties was analyzed.

  6. Effects of the gate recess structure on the DC electrical behavior of 0.1-μm metamorphic high-electron-mobility transistors

    International Nuclear Information System (INIS)

    Oh, Jung-Hun; Son, Myung-Sik; Lee, Bok-Hyung; Baek, Yong-Hyun; Jang, Hae-Kang; Rhee, Jin-Koo; Hwang, In-Seok; Kim, Sam-Dong

    2004-01-01

    We examine the effects of the gate recess structure on the DC characteristics of 0.1-μm metamorphic high-electron-mobility transistors (MHEMTs). Compared to the wide gate recess structure, the narrow gate recess structure shows a significant increase in the drain-source saturation current from 440 to 710 mA/mm and in the extrinsic transconductance from 420 to 910 mS/mm. We propose that the observed variations in the DC characteristics are due to deep-level accepter-type interface traps formed between the silicon-nitride passivation layer and the Schottky barrier layer. We perform device simulations by using the hydrodynamic model based upon the proposed mechanism, and the simulation results show good agreement with the data obtained from the fabricated devices.

  7. Differential interaction kinetics of a bipolar structure-specific endonuclease with DNA flaps revealed by single-molecule imaging.

    Directory of Open Access Journals (Sweden)

    Rachid Rezgui

    Full Text Available As DNA repair enzymes are essential for preserving genome integrity, understanding their substrate interaction dynamics and the regulation of their catalytic mechanisms is crucial. Using single-molecule imaging, we investigated the association and dissociation kinetics of the bipolar endonuclease NucS from Pyrococcus abyssi (Pab on 5' and 3'-flap structures under various experimental conditions. We show that association of the PabNucS with ssDNA flaps is largely controlled by diffusion in the NucS-DNA energy landscape and does not require a free 5' or 3' extremity. On the other hand, NucS dissociation is independent of the flap length and thus independent of sliding on the single-stranded portion of the flapped DNA substrates. Our kinetic measurements have revealed previously unnoticed asymmetry in dissociation kinetics from these substrates that is markedly modulated by the replication clamp PCNA. We propose that the replication clamp PCNA enhances the cleavage specificity of NucS proteins by accelerating NucS loading at the ssDNA/dsDNA junctions and by minimizing the nuclease interaction time with its DNA substrate. Our data are also consistent with marked reorganization of ssDNA and nuclease domains occurring during NucS catalysis, and indicate that NucS binds its substrate directly at the ssDNA-dsDNA junction and then threads the ssDNA extremity into the catalytic site. The powerful techniques used here for probing the dynamics of DNA-enzyme binding at the single-molecule have provided new insight regarding substrate specificity of NucS nucleases.

  8. Bipolar disorder: an overview

    African Journals Online (AJOL)

    which is the reason that up to 69% of patients with BD are misdiagnosed.1 Bipolar ... Cyclothymic disorder. • Substance/medication induced bipolar and related disorder. • Bipolar and related disorder due to another medical condition ... patients. Keywords: bipolar disorder, mania, depression, pharmacological management.

  9. Antiferromagnetic bipolar semiconductor LaMnPO with ZrCuSiAs-type structure

    OpenAIRE

    Yanagi, Hiroshi; Watanabe, Takumi; Kodama, Katsuaki; Iikubo, Satoshi; Shamoto, Shin-ichi; Kamiya, Toshio; Hirano, Masahiro; Hosono, Hideo

    2009-01-01

    Electronic and magnetic properties of a layered compound LaMnPO are examined in relation to a newly discovered iso-structural superconductor LaFeAs(P)O. Neutron diffraction measurements, together with temperature dependent magnetic susceptibility, clarify that LaMnPO is an antiferromagnet at least up to 375 K. The spin moment of a Mn ion is determined to be 2.26  µB at room temperature, and the spin configuration is antiparallel in the Mn–P plane and parallel between the Mn–P planes, which is...

  10. Transistor-based particle detection systems and methods

    Science.gov (United States)

    Jain, Ankit; Nair, Pradeep R.; Alam, Muhammad Ashraful

    2015-06-09

    Transistor-based particle detection systems and methods may be configured to detect charged and non-charged particles. Such systems may include a supporting structure contacting a gate of a transistor and separating the gate from a dielectric of the transistor, and the transistor may have a near pull-in bias and a sub-threshold region bias to facilitate particle detection. The transistor may be configured to change current flow through the transistor in response to a change in stiffness of the gate caused by securing of a particle to the gate, and the transistor-based particle detection system may configured to detect the non-charged particle at least from the change in current flow.

  11. High mobility and quantum well transistors design and TCAD simulation

    CERN Document Server

    Hellings, Geert

    2013-01-01

    For many decades, the semiconductor industry has miniaturized transistors, delivering increased computing power to consumers at decreased cost. However, mere transistor downsizing does no longer provide the same improvements. One interesting option to further improve transistor characteristics is to use high mobility materials such as germanium and III-V materials. However, transistors have to be redesigned in order to fully benefit from these alternative materials. High Mobility and Quantum Well Transistors: Design and TCAD Simulation investigates planar bulk Germanium pFET technology in chapters 2-4, focusing on both the fabrication of such a technology and on the process and electrical TCAD simulation. Furthermore, this book shows that Quantum Well based transistors can leverage the benefits of these alternative materials, since they confine the charge carriers to the high-mobility material using a heterostructure. The design and fabrication of one particular transistor structure - the SiGe Implant-Free Qu...

  12. Spin-dependent transport properties of a GaMnAs-based vertical spin metal-oxide-semiconductor field-effect transistor structure

    International Nuclear Information System (INIS)

    Kanaki, Toshiki; Asahara, Hirokatsu; Ohya, Shinobu; Tanaka, Masaaki

    2015-01-01

    We fabricate a vertical spin metal-oxide-semiconductor field-effect transistor (spin-MOSFET) structure, which is composed of an epitaxial single-crystal heterostructure with a ferromagnetic-semiconductor GaMnAs source/drain, and investigate its spin-dependent transport properties. We modulate the drain-source current I DS by ∼±0.5% with a gate-source voltage of ±10.8 V and also modulate I DS by up to 60% with changing the magnetization configuration of the GaMnAs source/drain at 3.5 K. The magnetoresistance ratio is more than two orders of magnitude higher than that obtained in the previous studies on spin MOSFETs. Our result shows that a vertical structure is one of the hopeful candidates for spin MOSFET when the device size is reduced to a sub-micron or nanometer scale

  13. Leakage current suppression with a combination of planarized gate and overlap/off-set structure in metal-induced laterally crystallized polycrystalline-silicon thin-film transistors

    Science.gov (United States)

    Chae, Hee Jae; Seok, Ki Hwan; Lee, Sol Kyu; Joo, Seung Ki

    2018-04-01

    A novel inverted staggered metal-induced laterally crystallized (MILC) polycrystalline-silicon (poly-Si) thin-film transistors (TFTs) with a combination of a planarized gate and an overlap/off-set at the source-gate/drain-gate structure were fabricated and characterized. While the MILC process is advantageous for fabricating inverted staggered poly-Si TFTs, MILC TFTs reveal higher leakage current than TFTs crystallized by other processes due to their high trap density of Ni contamination. Due to this drawback, the planarized gate and overlap/off-set structure were applied to inverted staggered MILC TFTs. The proposed device shows drastic suppression of leakage current and pinning phenomenon by reducing the lateral electric field and the space-charge limited current from the gate to the drain.

  14. Growth parameter optimization and interface treatment for enhanced electron mobility in heavily strained GaInAs/AlInAs high electron mobility transistor structures

    International Nuclear Information System (INIS)

    Fedoryshyn, Yuriy; Ostinelli, Olivier; Alt, Andreas; Pallin, Angel; Bolognesi, Colombo R.

    2014-01-01

    The optimization of heavily strained Ga 0.25 In 0.75 As/Al 0.48 In 0.52 As high electron mobility transistor structures is discussed in detail. The growth parameters and the channel layer interfaces were optimized in order to maximize the mobility of the two-dimensional electron gas. Structures composed of an 11 nm thick channel layer and a 4 nm thick spacer layer exhibited electron mobilities as high as 15 100 cm 2 /Vs and 70 000 cm 2 /Vs at 300 and 77 K, respectively, for channels including InAs strained layers. The sheet carrier density was kept above 2.5 × 10 12  cm −2 throughout the entire study

  15. Monolithic metal oxide transistors.

    Science.gov (United States)

    Choi, Yongsuk; Park, Won-Yeong; Kang, Moon Sung; Yi, Gi-Ra; Lee, Jun-Young; Kim, Yong-Hoon; Cho, Jeong Ho

    2015-04-28

    We devised a simple transparent metal oxide thin film transistor architecture composed of only two component materials, an amorphous metal oxide and ion gel gate dielectric, which could be entirely assembled using room-temperature processes on a plastic substrate. The geometry cleverly takes advantage of the unique characteristics of the two components. An oxide layer is metallized upon exposure to plasma, leading to the formation of a monolithic source-channel-drain oxide layer, and the ion gel gate dielectric is used to gate the transistor channel effectively at low voltages through a coplanar gate. We confirmed that the method is generally applicable to a variety of sol-gel-processed amorphous metal oxides, including indium oxide, indium zinc oxide, and indium gallium zinc oxide. An inverter NOT logic device was assembled using the resulting devices as a proof of concept demonstration of the applicability of the devices to logic circuits. The favorable characteristics of these devices, including (i) the simplicity of the device structure with only two components, (ii) the benign fabrication processes at room temperature, (iii) the low-voltage operation under 2 V, and (iv) the excellent and stable electrical performances, together support the application of these devices to low-cost portable gadgets, i.e., cheap electronics.

  16. Alcoholism and anxiety in bipolar illness : Differential lifetime anxiety comorbidity in bipolar I women with and without alcoholism

    NARCIS (Netherlands)

    Levander, Eric; Frye, Mark A.; McElroy, Susan; Suppes, Trisha; Grunze, Heinz; Nolen, Willem A.; Kupka, Ralph; Keck, Paul E.; Leverich, Gabriele S.; Altshuler, Lori L.; Hwang, Sun; Mintz, Jim; Post, Robert M.

    Introduction: This study was undertaken to evaluate the prevalence rate of anxiety comorbidity in bipolar subjects with and without alcohol use disorders (AUD). Methods: Bipolar men and women who entered the Stanley Foundation Bipolar Network (SFBN) underwent a Structured Clinical Interview for

  17. Synergistic effect of mixed neutron and gamma irradiation in bipolar operational amplifier OP07

    International Nuclear Information System (INIS)

    Yan, Liu; Wei, Chen; Shanchao, Yang; Xiaoming, Jin; Chaohui, He

    2016-01-01

    This paper presents the synergistic effects in bipolar operational amplifier OP07. The radiation effects are studied by neutron beam, gamma ray, and mixed neutron/gamma ray environments. The characterateristics of the synergistic effects are studied through comparison of different experiment results. The results show that the bipolar operational amplifier OP07 exhibited significant synergistic effects in the mixed neutron and gamma irradiation. The bipolar transistor is identified as the most radiation sensitive unit of the operational amplifier. In this paper, a series of simulations are performed on bipolar transistors in different radiation environments. In the theoretical simulation, the geometric model and calculations based on the Medici toolkit are built to study the radiation effects in bipolar components. The effect of mixed neutron and gamma irradiation is simulated based on the understanding of the underlying mechanisms of radiation effects in bipolar transistors. The simulated results agree well with the experimental data. The results of the experiments and simulation indicate that the radiation effects in the bipolar devices subjected to mixed neutron and gamma environments is not a simple combination of total ionizing dose (TID) effects and displacement damage. The data suggests that the TID effect could enhance the displacement damage. The synergistic effect should not be neglected in complex radiation environments.

  18. Synergistic effect of mixed neutron and gamma irradiation in bipolar operational amplifier OP07

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Liu, E-mail: liuyan@nint.ac.cn [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an 710024 (China); School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Wei, Chen; Shanchao, Yang; Xiaoming, Jin [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an 710024 (China); Chaohui, He [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China)

    2016-09-21

    This paper presents the synergistic effects in bipolar operational amplifier OP07. The radiation effects are studied by neutron beam, gamma ray, and mixed neutron/gamma ray environments. The characterateristics of the synergistic effects are studied through comparison of different experiment results. The results show that the bipolar operational amplifier OP07 exhibited significant synergistic effects in the mixed neutron and gamma irradiation. The bipolar transistor is identified as the most radiation sensitive unit of the operational amplifier. In this paper, a series of simulations are performed on bipolar transistors in different radiation environments. In the theoretical simulation, the geometric model and calculations based on the Medici toolkit are built to study the radiation effects in bipolar components. The effect of mixed neutron and gamma irradiation is simulated based on the understanding of the underlying mechanisms of radiation effects in bipolar transistors. The simulated results agree well with the experimental data. The results of the experiments and simulation indicate that the radiation effects in the bipolar devices subjected to mixed neutron and gamma environments is not a simple combination of total ionizing dose (TID) effects and displacement damage. The data suggests that the TID effect could enhance the displacement damage. The synergistic effect should not be neglected in complex radiation environments.

  19. A light-stimulated synaptic transistor with synaptic plasticity and memory functions based on InGaZnO{sub x}–Al{sub 2}O{sub 3} thin film structure

    Energy Technology Data Exchange (ETDEWEB)

    Li, H. K.; Chen, T. P., E-mail: echentp@ntu.edu.sg; Liu, P.; Zhang, Q. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Hu, S. G. [School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China); Liu, Y. [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu, Sichuan 610054 (China); Lee, P. S. [School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798 (Singapore)

    2016-06-28

    In this work, a synaptic transistor based on the indium gallium zinc oxide (IGZO)–aluminum oxide (Al{sub 2}O{sub 3}) thin film structure, which uses ultraviolet (UV) light pulses as the pre-synaptic stimulus, has been demonstrated. The synaptic transistor exhibits the behavior of synaptic plasticity like the paired-pulse facilitation. In addition, it also shows the brain's memory behaviors including the transition from short-term memory to long-term memory and the Ebbinghaus forgetting curve. The synapse-like behavior and memory behaviors of the transistor are due to the trapping and detrapping processes of the holes, which are generated by the UV pulses, at the IGZO/Al{sub 2}O{sub 3} interface and/or in the Al{sub 2}O{sub 3} layer.

  20. Excellent selector performance in engineered Ag/ZrO2:Ag/Pt structure for high-density bipolar RRAM applications

    Science.gov (United States)

    Wang, Chao; Song, Bing; Zeng, Zhongming

    2017-12-01

    A high-performance selector with bidirectional threshold switching (TS) characteristics of Ag/ZrO2/Pt structure was prepared by incorporating metallic Ag into the ZrO2 matrix. The bidirectional TS device exhibited excellent switching uniformity, forming-free behavior, ultra-low off current of volatile behavior could be explained by the self-dissolution of unstable filaments caused by minimization of the interfacial energy and thermal effect. Furthermore, a bipolar-type one selector-one resistor (1S-1R) memory device was successfully fabricated and exhibited significant suppression of the undesired sneak current, indicating the great potential as selector in a cross-point array.

  1. Bipolar Items

    Directory of Open Access Journals (Sweden)

    Nishiguchi Sumiyo

    2016-12-01

    Full Text Available This article asserts that the Japanese wide-scope mo ‘even’ in simple sentences are bipolar items (BPIs antilicensed or forbidden by negation and licensed in a non-monotonic (NM environment. BPIs share the features of negative polarity items (NPIs as well as positive polarity items (PPIs. The Dutch ooit ‘ever’, the Serbo-Croatian i-series ‘and/even’, and the Hungarian is-series ‘and/even’ are antilicensed by clausemate negation and licensed by extraclausal negation (van der Wouden, 1997; Progovac, 1994; Szabolcsi, 2002 or non-monotonic negative (and positive, for Serbo-Croatian emotive predicates. Adding an NPI rescues BPIs in uncomfortable clausemate negation.

  2. DeepBipolar: Identifying genomic mutations for bipolar disorder via deep learning.

    Science.gov (United States)

    Laksshman, Sundaram; Bhat, Rajendra Rana; Viswanath, Vivek; Li, Xiaolin

    2017-09-01

    Bipolar disorder, also known as manic depression, is a brain disorder that affects the brain structure of a patient. It results in extreme mood swings, severe states of depression, and overexcitement simultaneously. It is estimated that roughly 3% of the population of the United States (about 5.3 million adults) suffers from bipolar disorder. Recent research efforts like the Twin studies have demonstrated a high heritability factor for the disorder, making genomics a viable alternative for detecting and treating bipolar disorder, in addition to the conventional lengthy and costly postsymptom clinical diagnosis. Motivated by this study, leveraging several emerging deep learning algorithms, we design an end-to-end deep learning architecture (called DeepBipolar) to predict bipolar disorder based on limited genomic data. DeepBipolar adopts the Deep Convolutional Neural Network (DCNN) architecture that automatically extracts features from genotype information to predict the bipolar phenotype. We participated in the Critical Assessment of Genome Interpretation (CAGI) bipolar disorder challenge and DeepBipolar was considered the most successful by the independent assessor. In this work, we thoroughly evaluate the performance of DeepBipolar and analyze the type of signals we believe could have affected the classifier in distinguishing the case samples from the control set. © 2017 Wiley Periodicals, Inc.

  3. Meta-Analysis of Amygdala Volumes in Children and Adolescents with Bipolar Disorder

    Science.gov (United States)

    Pfeifer, Jonathan C.; Welge, Jeffrey; Strakowski. Stephen M.; Adler, Caleb M.; Delbello, Melissa P.

    2008-01-01

    The size of amygdala of bipolar youths and adults is investigated using neuroimaging studies. Findings showed that smaller volumes of amygdala were observed in youths with bipolar youths compared with children and adolescents without bipolar disorder. The structural amygdala abnormalities in bipolar youths are examined further.

  4. Improved hysteresis in a normally-off AlGaN/GaN MOS heterojunction field-effect transistor with a recessed gate structure formed by selective regrowth

    Science.gov (United States)

    Nakazawa, Satoshi; Shiozaki, Nanako; Negoro, Noboru; Tsurumi, Naohiro; Anda, Yoshiharu; Ishida, Masahiro; Ueda, Tetsuzo

    2017-09-01

    A normally-off AlGaN/GaN MOS heterojunction field-effect transistor (MOS-HFET) with a recessed gate structure formed by selective area regrowth is demonstrated. The fabricated MOS-HFET exhibits a threshold voltage of 1.7 V with an improved hysteresis of 0.5 V as compared with a device fabricated by a conventional dry etching process. An analysis of capacitance-voltage (C-V) characteristics reveals that the dry etching process increases interface state density and introduces an additional discrete trap. The use of the selective area regrowth technique effectively suppresses such degradation, avoiding the MOS interface from being exposed to dry etching. The results presented in this paper indicate that the selective area regrowth technique is promising for the fabrication of normally-off AlGaN/GaN MOS-HFETs.

  5. Nanoscale Vacuum Channel Transistor.

    Science.gov (United States)

    Han, Jin-Woo; Moon, Dong-Il; Meyyappan, M

    2017-04-12

    Vacuum tubes that sparked the electronics era had given way to semiconductor transistors. Despite their faster operation and better immunity to noise and radiation compared to the transistors, the vacuum device technology became extinct due to the high power consumption, integration difficulties, and short lifetime of the vacuum tubes. We combine the best of vacuum tubes and modern silicon nanofabrication technology here. The surround gate nanoscale vacuum channel transistor consists of sharp source and drain electrodes separated by sub-50 nm vacuum channel with a source to gate distance of 10 nm. This transistor performs at a low voltage (3 microamperes). The nanoscale vacuum channel transistor can be a possible alternative to semiconductor transistors beyond Moore's law.

  6. Complementary bipolar application specific analog semicustom array, intended to implement front-end units

    CERN Document Server

    Atkin, E; Kondratenko, S; Maslennikov, V; Meshcheriakov, V; Mishin, Yu; Volkov, Yu

    2002-01-01

    The structure of an analog semicustom array, intended to implement front-end electronics ICs on its basis, is considered. The features of this array are: implementation with an inexpensive bipolar process despite containing an equal number of NPN and PNP structures with well matched characteristics, supply voltages from 1.5 V to 15 V, transistor current gains Bst~100 and unity gain frequencies Ft > 3 GHz at collector currents of (100...300) mu A, high- and low-ohmic resistors, MOS capacitors, minimum two variable plating levels available. Specific circuit diagrams and parameters of the front-end electronics ICs, created on the basis of the considered array, are presented. The results of their tests are given. (4 refs).

  7. Characteristics and reliability of metal-oxide-semiconductor transistors with various depths of plasma-induced Si recess structure

    Science.gov (United States)

    Chen, Jone F.; Tsai, Yen-Lin; Chen, Chun-Yen; Hsu, Hao-Tang; Kao, Chia-Yu; Hwang, Hann-Ping

    2018-04-01

    Device characteristics and hot-carrier-induced device degradation of n-channel MOS transistors with an off-state breakdown voltage of approximately 25 V and various Si recess depths introduced by sidewall spacer overetching are investigated. Experimental data show that the depth of the Si recess has small effects on device characteristics. A device with a deeper Si recess has lower substrate current and channel electric field, whereas a greater hot-carrier-induced device degradation and a shorter hot-carrier lifetime are observed. Results of technology computer-aided design simulations suggest that these unexpected observations are related to the severity of plasma damage caused by the sidewall spacer overetching and the difference in topology.

  8. Optical driven electromechanical transistor based on tunneling effect.

    Science.gov (United States)

    Jin, Leisheng; Li, Lijie

    2015-04-15

    A new electromechanical transistor based on an optical driven vibrational ring structure has been postulated. In the device, optical power excites the ring structure to vibrate, which acts as the shuttle transporting electrons from one electrode to the other forming the transistor. The electrical current of the transistor is adjusted by the optical power. Coupled opto-electro-mechanical simulation has been performed. It is shown from the dynamic analysis that the stable working range of the transistor is much wider than that of the optical wave inside the cavity, i.e., the optical resonance enters nonperiodic states while the mechanical vibration of the ring is still periodic.

  9. Recent progress in photoactive organic field-effect transistors

    Directory of Open Access Journals (Sweden)

    Yutaka Wakayama

    2014-04-01

    Full Text Available Recent progress in photoactive organic field-effect transistors (OFETs is reviewed. Photoactive OFETs are divided into light-emitting (LE and light-receiving (LR OFETs. In the first part, LE-OFETs are reviewed from the viewpoint of the evolution of device structures. Device performances have improved in the last decade with the evolution of device structures from single-layer unipolar to multi-layer ambipolar transistors. In the second part, various kinds of LR-OFETs are featured. These are categorized according to their functionalities: phototransistors, non-volatile optical memories, and photochromism-based transistors. For both, various device configurations are introduced: thin-film based transistors for practical applications, single-crystalline transistors to investigate fundamental physics, nanowires, multi-layers, and vertical transistors based on new concepts.

  10. Recent progress in photoactive organic field-effect transistors.

    Science.gov (United States)

    Wakayama, Yutaka; Hayakawa, Ryoma; Seo, Hoon-Seok

    2014-04-01

    Recent progress in photoactive organic field-effect transistors (OFETs) is reviewed. Photoactive OFETs are divided into light-emitting (LE) and light-receiving (LR) OFETs. In the first part, LE-OFETs are reviewed from the viewpoint of the evolution of device structures. Device performances have improved in the last decade with the evolution of device structures from single-layer unipolar to multi-layer ambipolar transistors. In the second part, various kinds of LR-OFETs are featured. These are categorized according to their functionalities: phototransistors, non-volatile optical memories, and photochromism-based transistors. For both, various device configurations are introduced: thin-film based transistors for practical applications, single-crystalline transistors to investigate fundamental physics, nanowires, multi-layers, and vertical transistors based on new concepts.

  11. The growth and characterization of group III-nitride transistor devices grown by metalorganic chemical vapor deposition

    Science.gov (United States)

    Wong, Michael Ming

    The InAlGaN, or III-nitride, material system has received much interest from the research community. A direct wide bandgap semiconductor, GaN offers a high breakdown field (>3 x 106 V/cm) due to its large bandgap energy of 3.4 eV, high electron saturation velocity (1.5 x 10 7 cm/s, predicted peak up to 2.7 x 107 cm/s), good thermal conductivity (≥1.7 W/cm K), and reasonable mobility (800 cm 2/V s). In an AlGaN/GaN heterostructure, the formation of a two-dimensional electron gas (2DEG) leads to a higher electron mobility (2000 cm2/V s) and a high sheet density (1--5 x 1013 cm -2). This makes transistors based on the III-nitride material system ideal for high-temperature, high-power, and high-frequency applications. Two such transistors include the heterojunction field-effect transistor (HFET) and bipolar junction transistor (BJT), which includes the heterojunction bipolar transistor (HBT). Both HFETs and HBTs were studied, and the epitaxial heterostructures were grown by the metalorganic chemical vapor deposition (MOCVD) technique. The MOCVD process and system are described, along with the growth details. As material characterization is important for the optimization of growth, several of the techniques used are discussed. An extensive study to improve the performance of AlGaN/GaN HFETs is detailed. Through the use of a delta-doped, binary barrier novel device structure, the highest reported maximum drain current and transconductance is reported: IDSmax = 1.82 A/mm and gm = 331 mS/mm. The device also exhibits excellent RF characteristics. HBTs based on the III-nitride material system face a more difficult challenge associated with p-type material. Development of HBTs is still in the early stages, although there are reports of working devices. The gain is still below its potential, but many of the issues have been identified. Two novel structures are reported for the first time, a GaN/InGaN/GaN pnp HBT and a AlGaN/GaN npn graded-base and collector-up HBT. The

  12. Spin gated transistors for reprogrammable logic

    Science.gov (United States)

    Ciccarelli, Chiara; Gonzalez-Zalba, Fernando; Irvine, Andrew; Campion, Richard; Zarbo, Liviu; Gallagher, Brian; Ferguson, Andrew; Jungwirth, Tomas; Wunderlich, Joerg; Institute of Physics ASCR Collaboration; University of Nottingham Collaboration; Hitachi Cambridge Laboratory Team; Institute of Physics ASCR Collaboration; University of Nottingham Collaboration; University of Cambridge Team

    2014-03-01

    In spin-orbit coupled magnetic materials the chemical potential depends on the orientation of the magnetisation. By making the gate of a field effect transistor magnetic, it is possible to tune the channel conductance not only electrically but also magnetically. We show that these magnetic transistor can be used to realise non-volatile reprogrammable Boolean logic. The non-volatile reconfigurable capability resides in the magnetization-dependent band structure of the magnetic stack. A change in magnetization orientation produces a change in the electrochemical potential, which induces a charge accumulation in the correspondent gate electrode. This is readily sensed by a field-effect device such as standard field-effect transistors or more exotic single-electron transistors. We propose circuits for low power consumption applications that can be magnetically switched between NAND and OR logic functions and between NOR and AND logic functions.

  13. Oxide bipolar electronics: materials, devices and circuits

    Science.gov (United States)

    Grundmann, Marius; Klüpfel, Fabian; Karsthof, Robert; Schlupp, Peter; Schein, Friedrich-Leonhard; Splith, Daniel; Yang, Chang; Bitter, Sofie; von Wenckstern, Holger

    2016-06-01

    We present the history of, and the latest progress in, the field of bipolar oxide thin film devices. As such we consider primarily pn-junctions in which at least one of the materials is a metal oxide semiconductor. A wide range of n-type and p-type oxides has been explored for the formation of such bipolar diodes. Since most oxide semiconductors are unipolar, challenges and opportunities exist with regard to the formation of heterojunction diodes and band lineups. Recently, various approaches have led to devices with high rectification, namely p-type ZnCo2O4 and NiO on n-type ZnO and amorphous zinc-tin-oxide. Subsequent bipolar devices and applications such as photodetectors, solar cells, junction field-effect transistors and integrated circuits like inverters and ring oscillators are discussed. The tremendous progress shows that bipolar oxide electronics has evolved from the exploration of various materials and heterostructures to the demonstration of functioning integrated circuits. Therefore a viable, facile and high performance technology is ready for further exploitation and performance optimization.

  14. Hetero-gate-dielectric double gate junctionless transistor (HGJLT) with reduced band-to-band tunnelling effects in subthreshold regime

    Science.gov (United States)

    Ghosh, Bahniman; Mondal, Partha; Akram, M. W.; Bal, Punyasloka; Salimath, Akshay Kumar

    2014-06-01

    We propose a hetero-gate-dielectric double gate junctionless transistor (HGJLT), taking high-k gate insulator at source side and low-k gate insulator at drain side, which reduces the effects of band-to-band tunnelling (BTBT) in the sub-threshold region. A junctionless transistor (JLT) is turned off by the depletion of carriers in the highly doped thin channel (device layer) which results in a significant band overlap between the valence band of the channel region and the conduction band of the drain region, due to off-state drain bias, that triggers electrons to tunnel from the valence band of the channel region to the conduction band of the drain region leaving behind holes in the channel. These effects of band-to-band tunnelling increase the sub-threshold leakage current, and the accumulation of holes in the channel forms a parasitic bipolar junction transistor (n-p-n BJT for channel JLT) in the lateral direction by the source (emitter), channel (base) and drain (collector) regions in JLT structure in off-state. The proposed HGJLT reduces the subthreshold leakage current and suppresses the parasitic BJT action in off-state by reducing the band-to-band tunnelling probability.

  15. Types of Bipolar Disorder

    Science.gov (United States)

    ... many people have bipolar disorder along with another illness such as anxiety disorder, substance abuse, or an eating disorder. People with ... are sometimes misdiagnosed with schizophrenia. Anxiety and ADHD: ... such as bipolar disorder. Risk Factors Scientists are ...

  16. Genetics of bipolar disorder

    Directory of Open Access Journals (Sweden)

    Kerner B

    2014-02-01

    Full Text Available Berit Kerner Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA Abstract: Bipolar disorder is a common, complex genetic disorder, but the mode of transmission remains to be discovered. Many researchers assume that common genomic variants carry some risk for manifesting the disease. The research community has celebrated the first genome-wide significant associations between common single nucleotide polymorphisms (SNPs and bipolar disorder. Currently, attempts are under way to translate these findings into clinical practice, genetic counseling, and predictive testing. However, some experts remain cautious. After all, common variants explain only a very small percentage of the genetic risk, and functional consequences of the discovered SNPs are inconclusive. Furthermore, the associated SNPs are not disease specific, and the majority of individuals with a “risk” allele are healthy. On the other hand, population-based genome-wide studies in psychiatric disorders have rediscovered rare structural variants and mutations in genes, which were previously known to cause genetic syndromes and monogenic Mendelian disorders. In many Mendelian syndromes, psychiatric symptoms are prevalent. Although these conditions do not fit the classic description of any specific psychiatric disorder, they often show nonspecific psychiatric symptoms that cross diagnostic boundaries, including intellectual disability, behavioral abnormalities, mood disorders, anxiety disorders, attention deficit, impulse control deficit, and psychosis. Although testing for chromosomal disorders and monogenic Mendelian disorders is well established, testing for common variants is still controversial. The standard concept of genetic testing includes at least three broad criteria that need to be fulfilled before new genetic tests should be introduced: analytical validity, clinical validity, and clinical utility. These criteria are

  17. Radiation effect on silicon transistors in mixed neutrons-gamma environment

    Science.gov (United States)

    Assaf, J.; Shweikani, R.; Ghazi, N.

    2014-10-01

    The effects of gamma and neutron irradiations on two different types of transistors, Junction Field Effect Transistor (JFET) and Bipolar Junction Transistor (BJT), were investigated. Irradiation was performed using a Syrian research reactor (RR) (Miniature Neutron Source Reactor (MNSR)) and a gamma source (Co-60 cell). For RR irradiation, MCNP code was used to calculate the absorbed dose received by the transistors. The experimental results showed an overall decrease in the gain factors of the transistors after irradiation, and the JFETs were more resistant to the effects of radiation than BJTs. The effect of RR irradiation was also greater than that of gamma source for the same dose, which could be because neutrons could cause more damage than gamma irradiation.

  18. Specifics of Pulsed Arc Welding Power Supply Performance Based On A Transistor Switch

    Science.gov (United States)

    Krampit, N. Yu; Kust, T. S.; Krampit, M. A.

    2016-08-01

    Specifics of designing a pulsed arc welding power supply device are presented in the paper. Electronic components for managing large current was analyzed. Strengths and shortcomings of power supply circuits based on thyristor, bipolar transistor and MOSFET are outlined. As a base unit for pulsed arc welding was chosen MOSFET transistor, which is easy to manage. Measures to protect a transistor are given. As for the transistor control device is a microcontroller Arduino which has a low cost and adequate performance of the work. Bead transfer principle is to change the voltage on the arc in the formation of beads on the wire end. Microcontroller controls transistor when the arc voltage reaches the threshold voltage. Thus there is a separation and transfer of beads without splashing. Control strategies tested on a real device and presented. The error in the operation of the device is less than 25 us, it can be used controlling drop transfer at high frequencies (up to 1300 Hz).

  19. Effects of Si3N4 passivation on the dc and RF characteristics of metamorphic high-electron-mobility transistors depending on the gate-recess structures

    International Nuclear Information System (INIS)

    Oh, J H; Han, M; Baek, Y H; Moon, S W; Rhee, J K; Kim, S D

    2009-01-01

    Effects of the Si 3 N 4 passivation on the dc and RF characteristics of a 0.1 µm metamorphic high-electron-mobility transistor (HEMT) are investigated for narrow and wide gate-recess structures. Maximum drain-source saturation current (I dss,max ) and maximum extrinsic transconductance (g m,max ) are reduced by ∼14.8 and ∼11.6%, respectively, in the wide gate-recess structure after the passivation; on the other hand, only ∼5.7 and ∼4.9% reductions are measured from I dss,max and g m,max , respectively, in the narrow gate-recess structure. We examine the passivation-induced degradation by using a modified charge control model assuming the charged surface states on the Si 3 N 4 interface and a comparative study of the hydrodynamic device simulation with the experimental measurement. From the analysis, it is proposed that the difference of degradation in two different gate structures is due to an approximately three times higher charged surface state density of ∼4.5 × 10 11 cm −2 in the wide gate-recess structure than ∼1.6 × 10 11 cm −2 in the narrow gate-recess structure. The cut-off frequency (f T ) of the wide gate-recess structure also exhibits a greater reduction of ∼14.5%, while the f T of the narrow gate-recess structure is reduced by only ∼6.6% after the passivation. This is mainly due to the passivation-induced surface states of a higher density in the wide gate-recess structure. A great increase of the gate-to-drain parasitic capacitance in the wide gate-recess structure makes a major contribution to ∼13.5% degradation of the maximum frequency of oscillation

  20. Bipolar disorder diagnosis: challenges and future directions

    Science.gov (United States)

    Phillips, Mary L; Kupfer, David J

    2018-01-01

    Bipolar disorder refers to a group of affective disorders, which together are characterised by depressive and manic or hypomanic episodes. These disorders include: bipolar disorder type I (depressive and manic episodes: this disorder can be diagnosed on the basis of one manic episode); bipolar disorder type II (depressive and hypomanic episodes); cyclothymic disorder (hypomanic and depressive symptoms that do not meet criteria for depressive episodes); and bipolar disorder not otherwise specified (depressive and hypomanic-like symptoms that do not meet the diagnostic criteria for any of the aforementioned disorders). Bipolar disorder type II is especially difficult to diagnose accurately because of the difficulty in differentiation of this disorder from recurrent unipolar depression (recurrent depressive episodes) in depressed patients. The identification of objective biomarkers that represent pathophysiologic processes that differ between bipolar disorder and unipolar depression can both inform bipolar disorder diagnosis and provide biological targets for the development of new and personalised treatments. Neuroimaging studies could help the identification of biomarkers that differentiate bipolar disorder from unipolar depression, but the problem in detection of a clear boundary between these disorders suggests that they might be better represented as a continuum of affective disorders. Innovative combinations of neuroimaging and pattern recognition approaches can identify individual patterns of neural structure and function that accurately ascertain where a patient might lie on a behavioural scale. Ultimately, an integrative approach, with several biological measurements using different scales, could yield patterns of biomarkers (biosignatures) to help identify biological targets for personalised and new treatments for all affective disorders. PMID:23663952

  1. Cytokines in bipolar disorder

    DEFF Research Database (Denmark)

    Munkholm, Klaus; Vinberg, Maj; Vedel Kessing, Lars

    2012-01-01

    to affective state. METHODS: We conducted a systemtic review of studies measuring endogenous cytokine concentrations in patients with bipolar disorder and a meta-analysis, reporting results according to the PRISMA statement. RESULTS: Thirteen studies were included, comprising 556 bipolar disorder patients......BACKGROUND: Current research and hypothesis regarding the pathophysiology of bipolar disorder suggests the involvement of immune system dysfunction that is possibly related to disease activity. Our objective was to systematically review evidence of cytokine alterations in bipolar disorder according...

  2. Psychotic and Bipolar Disorders: Bipolar Disorder.

    Science.gov (United States)

    Holder, Sarah D

    2017-04-01

    Bipolar disorder is a severe chronic mental illness that affects a large number of individuals. This disorder is separated into two major types, bipolar I disorder, with mania and typically recurrent depression, and bipolar II disorder, with recurrent major depression and hypomania. Patients with bipolar disorder spend the majority of time experiencing depression, and this typically is the presenting symptom. Because outcomes are improved with earlier diagnosis and treatment, physicians should maintain a high index of suspicion for bipolar disorder. The most effective long-term treatments are lithium and valproic acid, although other drugs also are used. In addition to referral to a mental health subspecialist for initiation and management of drug treatment, patients with bipolar disorder should be provided with resources for psychotherapy. Several comorbidities commonly associated with bipolar disorder include other mental disorders, substance use disorders, migraine headaches, chronic pain, stroke, metabolic syndrome, and cardiovascular disease. Family physicians who care for patients with bipolar disorder should focus their efforts on prevention and management of comorbidities. These patients should be assessed continually for risk of suicide because they are at high risk and their suicide attempts tend to be successful. Written permission from the American Academy of Family Physicians is required for reproduction of this material in whole or in part in any form or medium.

  3. Integral optoelectronic switch based on DMOS-transistors

    Directory of Open Access Journals (Sweden)

    Politanskyy L. F.

    2008-12-01

    Full Text Available The characteristics of optoelectronic couples photodiodes-DMOS-transistor are studied in the paper. There was developed a mathematical model of volt-ampere characteristic of the given optoelectronic couple which allows to determine interrelation of its electric parameters with constructive and electrophysical parameters of photodiodes and DMOS-transistors. There was suggested a construction of integral optoelectronic switch, based on DMOS-transistors on the silicon with dielectric insulation structures (SDIS. Possible is the optic control of executive devices, connected both to the source and drain circuits of the switching transistor.

  4. Nutrition and Bipolar Depression.

    Science.gov (United States)

    Beyer, John L; Payne, Martha E

    2016-03-01

    As with physical conditions, bipolar disorder is likely to be impacted by diet and nutrition. Patients with bipolar disorder have been noted to have relatively unhealthy diets, which may in part be the reason they also have an elevated risk of metabolic syndrome and obesity. An improvement in the quality of the diet should improve a bipolar patient's overall health risk profile, but it may also improve their psychiatric outcomes. New insights into biological dysfunctions that may be present in bipolar disorder have presented new theoretic frameworks for understanding the relationship between diet and bipolar disorder. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Development of Gate and Base Drive Using SiC Junction Field Effect Transistors

    Science.gov (United States)

    2008-05-01

    Agarwal, Anant; Richmond, James ; Chow, T. Paul; Geil, Bruce; Jones, Ken A.; Scozzie, Charles. 4 kV, 10 A Bipolar Junction Transistors in 4H-SiC. Proc...PROVING GROUND MD 21005-5001 1 US ARMY TRADOC BATTLE LAB INTEGRATION & TECHL DIRCTRT ATTN ATCD B 10 WHISTLER LANE FT MONROE

  6. Study of radiation (neutrons, γ-rays, and carbon-ions) effects on NPN transistors

    International Nuclear Information System (INIS)

    Croitoru, N.; D'Angelo, P.; Rancoita, P.G.; Rattaggi, M.; Seidman, A.; Croitoru, N.; Seidman, A.

    1999-01-01

    Bipolar npn-transistors, irradiated by neutrons, γ-rays, and ions, showed an I B increase, which resulted in a lower current gain (β F ). The variation of 1/β F was found to be proportional to the expected number of Frenkel pairs/μm, regardless of the radiation type. (authors)

  7. Bipolar Treatment: Are Bipolar I and Bipolar II Treated Differently?

    Science.gov (United States)

    ... management strategies. In addition to medications and other types of treatment, successful management of your bipolar disorder includes living a healthy lifestyle, such as getting enough sleep, eating a healthy diet and being physically active. ...

  8. Field-effect transistor structures on the basis of poly(3-hexylthiophene), fullerene derivatives [60]PCBM, [70]PCBM, and nickel nanoparticles

    Science.gov (United States)

    Aleshin, A. N.; Shcherbakov, I. P.; Trapeznikova, I. N.; Petrov, V. N.

    2016-09-01

    Organic field-effect transistor (OFET) structures with the active layers on the basis of composite films of semiconductor polymer poly(3-hexylthiophene) (P3HT), fullerene derivatives [60]PCBM, [70]PCBM, and nickel (Ni) nanoparticles are obtained, and their optical, electrical, and photoelectrical properties are studied. It is shown that introducing Ni nanoparticles into P3HT: [60]PCBM and P3HT: [70]PCBM films leads to an increase in the absorption and to quenching of photoluminescence of the composite in the 400-600 nm spectral band due to the plasmon effect. In P3HT: [60]PCBM: Ni and P3HT: [70]PCBM: Ni OFET structures at the P3HT: [60]PCBM and P3HT: [70]PCBM concentrations of ~1: 1 and Ni concentrations of ~3-5 wt %, current-voltage ( I-V) characteristics typical of ambipolar OFETs with the dominant hole conduction are observed. The charge-carrier (hole) mobilities calculated from the I-V characteristic at V G =-10 V were found to be ~0.46 cm2/(V s) for P3HT: [60]PCBM: Ni and ~4.7 cm2/(V s) for P3HT: [70]PCBM: Ni, which means that the mobility increases if [60]PCBM in the composition is replaced with [70]PCBM. The effect of light on the I-V characteristics of P3HT: [60]PCBM: Ni and P3HT: [70]PCBM: Ni OFETs is studied.

  9. Fabrication of field-effect transistor utilizing oriented thin film of octahexyl-substituted phthalocyanine and its electrical anisotropy based on columnar structure

    Science.gov (United States)

    Ohmori, Masashi; Nakatani, Mitsuhiro; Kajii, Hirotake; Miyamoto, Ayano; Yoneya, Makoto; Fujii, Akihiko; Ozaki, Masanori

    2018-03-01

    Field-effect transistors with molecularly oriented thin films of metal-free non-peripherally octahexyl-substituted phthalocyanine (C6PcH2), which characteristically form a columnar structure, have been fabricated, and the electrical anisotropy of C6PcH2 has been investigated. The molecularly oriented thin films of C6PcH2 were prepared by the bar-coating technique, and the uniform orientation in a large area and the surface roughness at a molecular level were observed by polarized spectroscopy and atomic force microscopy, respectively. The field effect mobilities parallel and perpendicular to the column axis of C6PcH2 were estimated to be (1.54 ± 0.24) × 10‑2 and (2.10 ± 0.23) × 10‑3 cm2 V‑1 s‑1, respectively. The electrical anisotropy based on the columnar structure has been discussed by taking the simulated results obtained by density functional theory calculation into consideration.

  10. A clinical case-based hypothesis: secretory IgA operates as an electronic transistor controlling the selection or rejection of molecules in the absorption process in the lumen of gastrointestinal tract

    Directory of Open Access Journals (Sweden)

    Zamm AV

    2013-09-01

    Full Text Available Alfred V Zamm Retired, Malibu, CA, USA Abstract: There is a clinical correlation between (1 an allergic patient's ability to resist the development of symptoms that would have resulted from an allergenic challenge, (2 the magnitude of geomagnetism at a geographic site, and (3 the amount of solar energy falling on that site. It is suggested that the digestive membrane has an electronic gatekeeper that “decides” electronically which molecules to allow or not allow to pass on to the absorptive surface. The unique bipolar structure of secretory immunoglobulin A (IgA, having a central secretory piece and the resultant unique electronic function of this polarized molecule, allows it to function as an electronic transistor, producing an electronic gatekeeper in the form of an electronic sieve. Keywords: geomagnetism, atmospheric negative ions, electronic transistor, secretory IgA, food allergies, autoimmunity

  11. Excellent selector performance in engineered Ag/ZrO2:Ag/Pt structure for high-density bipolar RRAM applications

    Directory of Open Access Journals (Sweden)

    Chao Wang

    2017-12-01

    Full Text Available A high-performance selector with bidirectional threshold switching (TS characteristics of Ag/ZrO2/Pt structure was prepared by incorporating metallic Ag into the ZrO2 matrix. The bidirectional TS device exhibited excellent switching uniformity, forming-free behavior, ultra-low off current of <1 nA and adjustable selectivity (from 102 to 107. The experiment results confirmed that metallic Ag clusters were penetrated into the ZrO2 matrix during the annealing process, which would function as an effective active source responsible for the bidirectional TS. The volatile behavior could be explained by the self-dissolution of unstable filaments caused by minimization of the interfacial energy and thermal effect. Furthermore, a bipolar-type one selector-one resistor (1S-1R memory device was successfully fabricated and exhibited significant suppression of the undesired sneak current, indicating the great potential as selector in a cross-point array.

  12. Temperature characteristics research of SOI pressure sensor based on asymmetric base region transistor

    Science.gov (United States)

    Zhao, Xiaofeng; Li, Dandan; Yu, Yang; Wen, Dianzhong

    2017-07-01

    Based on the asymmetric base region transistor, a pressure sensor with temperature compensation circuit is proposed in this paper. The pressure sensitive structure of the proposed sensor is constructed by a C-type silicon cup and a Wheatstone bridge with four piezoresistors ({R}1, {R}2, {R}3 and {R}4) locating on the edge of a square silicon membrane. The chip was designed and fabricated on a silicon on insulator (SOI) wafer by micro electromechanical system (MEMS) technology and bipolar transistor process. When the supply voltage is 5.0 V, the corresponding temperature coefficient of the sensitivity (TCS) for the sensor before and after temperature compensation are -1862 and -1067 ppm/°C, respectively. Through varying the ratio of the base region resistances {r}1 and {r}2, the TCS for the sensor with the compensation circuit is -127 ppm/°C. It is possible to use this compensation circuit to improve the temperature characteristics of the pressure sensor. Project supported by the National Natural Science Foundation of China (No. 61471159), the Natural Science Foundation of Heilongjiang Province (No. F201433), the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province (No. 2015018), and the Special Funds for Science and Technology Innovation Talents of Harbin in China (No. 2016RAXXJ016).

  13. Ballistic Phosphorene Transistor

    Science.gov (United States)

    2015-11-19

    satisfactory. W911NF-14-1-0572 -II 66414-EL-II.3 TO:(1) Electronics Division (Qiu, Joe) TITLE: Final Report: Ballistic Phosphorene Transistor (x) Material... Transistor ” as a STIP award for the period 09/1/2014 through 5/31/2015. The ARO program director responsible for the grant is Dr. Joe Qiu. The PI is Prof...UU 19-11-2015 1-Sep-2014 31-May-2015 Approved for Public Release; Distribution Unlimited Final Report: Ballistic Phosphorene Transistor The views

  14. Bipolar soft connected, bipolar soft disconnected and bipolar soft compact spaces

    Directory of Open Access Journals (Sweden)

    Muhammad Shabir

    2017-06-01

    Full Text Available Bipolar soft topological spaces are mathematical expressions to estimate interpretation of data frameworks. Bipolar soft theory considers the core features of data granules. Bipolarity is important to distinguish between positive information which is guaranteed to be possible and negative information which is forbidden or surely false. Connectedness and compactness are the most important fundamental topological properties. These properties highlight the main features of topological spaces and distinguish one topology from another. Taking this into account, we explore the bipolar soft connectedness, bipolar soft disconnectedness and bipolar soft compactness properties for bipolar soft topological spaces. Moreover, we introduce the notion of bipolar soft disjoint sets, bipolar soft separation, and bipolar soft hereditary property and study on bipolar soft connected and disconnected spaces. By giving the detailed picture of bipolar soft connected and disconnected spaces we investigate bipolar soft compact spaces and derive some results related to this concept.

  15. Bipolar characteristics of AlGaN/AlN/GaN/AlGaN double heterojunction structure with AlGaN as buffer layer

    International Nuclear Information System (INIS)

    Peng, Enchao; Wang, Xiaoliang; Xiao, Hongling; Wang, Cuimei; Yin, Haibo; Chen, Hong; Feng, Chun; Jiang, Lijuan; Hou, Xun; Wang, Zhanguo

    2013-01-01

    Highlights: •2DEG and 2DHG coexist in the AlGaN/AlN/GaN/AlGaN DH-structure. •The sheet densities of 2DEG and 2DHG vary with buffer Al content and GaN thickness. •The conditions for the disappearance of 2DHG are discussed. •Increasing buffer Al content provides better electron confinement. •Dislocation scattering is reduced in the DH-structure. -- Abstract: This is a theoretical study of AlGaN/AlN/GaN/AlGaN double heterojunction (DH) structure with AlGaN as buffer layer. Our calculation shows that as the buffer Al content increases, though two-dimensional electron gas (2DEG) sheet density decreases, the channel back-barrier caused by polarization-induced electric field in GaN provides better electron confinement. And under certain conditions the DH-structure shows bipolar characteristics, with an additional two-dimensional hole gas (2DHG) formed at GaN/AlGaN interface. The influence of the buffer Al content and GaN channel thickness on the 2DEG and 2DHG sheet densities are investigated, and the conditions for the disappearance of 2DHG are discussed. Also, the mobility inhibited by dislocation scattering is enhanced in DH-structure due to the enhancement of screening effect of the 2DEG

  16. Silicon nanowire transistors

    CERN Document Server

    Bindal, Ahmet

    2016-01-01

    This book describes the n and p-channel Silicon Nanowire Transistor (SNT) designs with single and dual-work functions, emphasizing low static and dynamic power consumption. The authors describe a process flow for fabrication and generate SPICE models for building various digital and analog circuits. These include an SRAM, a baseband spread spectrum transmitter, a neuron cell and a Field Programmable Gate Array (FPGA) platform in the digital domain, as well as high bandwidth single-stage and operational amplifiers, RF communication circuits in the analog domain, in order to show this technology’s true potential for the next generation VLSI. Describes Silicon Nanowire (SNW) Transistors, as vertically constructed MOS n and p-channel transistors, with low static and dynamic power consumption and small layout footprint; Targets System-on-Chip (SoC) design, supporting very high transistor count (ULSI), minimal power consumption requiring inexpensive substrates for packaging; Enables fabrication of different types...

  17. Outlook and emerging semiconducting materials for ambipolar transistors.

    Science.gov (United States)

    Bisri, Satria Zulkarnaen; Piliego, Claudia; Gao, Jia; Loi, Maria Antonietta

    2014-02-26

    Ambipolar or bipolar transistors are transistors in which both holes and electrons are mobile inside the conducting channel. This device allows switching among several states: the hole-dominated on-state, the off-state, and the electron-dominated on-state. In the past year, it has attracted great interest in exotic semiconductors, such as organic semiconductors, nanostructured materials, and carbon nanotubes. The ability to utilize both holes and electrons inside one device opens new possibilities for the development of more compact complementary metal-oxide semiconductor (CMOS) circuits, and new kinds of optoelectronic device, namely, ambipolar light-emitting transistors. This progress report highlights the recent progresses in the field of ambipolar transistors, both from the fundamental physics and application viewpoints. Attention is devoted to the challenges that should be faced for the realization of ambipolar transistors with different material systems, beginning with the understanding of the importance of interface modification, which heavily affects injections and trapping of both holes and electrons. The recent development of advanced gating applications, including ionic liquid gating, that open up more possibility to realize ambipolar transport in materials in which one type of charge carrier is highly dominant is highlighted. Between the possible applications of ambipolar field-effect transistors, we focus on ambipolar light-emitting transistors. We put this new device in the framework of its prospective for general lightings, embedded displays, current-driven laser, as well as for photonics-electronics interconnection. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Effect of Ti Doping to Maintain Structural Disorder in InOx-Based Thin-Film Transistors Fabricated by RF Magnetron Sputtering

    Science.gov (United States)

    Aikawa, Shinya

    2017-12-01

    The effect of Ti doping in an indium oxide (InOx)-based semiconductor is investigated for the thin-film transistor (TFT) property and crystal structure of the film. InOx and Ti-doped InOx (InTiOx) films deposited by RF magnetron sputtering under the same O2 partial pressure conditions were systematically compared. The TFT behavior of the InOx showed higher conductivity than that of the InTiOx and was drastically changed to metallic conduction after annealing at 150 °C. Under the annealing conditions when the electrical transition to the metallic behavior occurred, the InOx film was crystallized. The X-ray diffraction analysis revealed that the shrinkage of the In2O3 unit cell is pronounced in the case of InOx films. Thus, Ti dopants may play the role as a suppressor for shrinkage of the unit cell, i.e. maintaining neighboring In-In distances, in addition to suppression of oxygen vacancies. The In-In distance, which is related to the overlapping of In 5 s orbitals, is considered to be one of the key factor for which InOx-based materials are utilized as conducting films or semiconducting channels.

  19. Breakdown mechanism in AlGaN/GaN high-electron mobility transistor structure on free-standing n-type GaN substrate

    Science.gov (United States)

    Tanabe, Shinichi; Watanabe, Noriyuki; Matsuzaki, Hideaki

    2016-05-01

    The breakdown mechanism in a high-electron mobility transistor structure on free-standing n-type GaN substrates consisting of a C-doped GaN layer as a high-resistivity buffer was investigated with a two-terminal vertical device that has a C-doped GaN buffer between electrodes. Initially, current density increases with the square of bias voltage. This is then followed by an abrupt increase by several orders of magnitude within ten volts, which results in breakdown. These behaviors are consistent with the theory of the space-charge limited current. In this theory, current density increases steeply when trap sites at a certain energy level are completely filled with injected carriers. These results indicate that the existence of trap levels in the C-doped GaN layer is one of the possible factors that determine the breakdown. The trap density and trap level of the C-doped GaN layer were also evaluated.

  20. New Benzimidazole-Based Bipolar Hosts: Highly Efficient Phosphorescent and Thermally Activated Delayed Fluorescent Organic Light-Emitting Diodes Employing the Same Device Structure.

    Science.gov (United States)

    Zhao, Yali; Wu, Chao; Qiu, Panlong; Li, Xiaoping; Wang, Qiang; Chen, Jiangshan; Ma, Dongge

    2016-02-03

    The rapid development of the thermally activated delayed fluorescence (TADF) emitters makes it necessary to produce new versatile host materials for both phosphorescent and TADF emitters. Three new bipolar host materials, 9,9'-(2'-(1H-benzimidazol-1-yl)-[1,1'-biphenyl]-3,5-diyl)bis(9H-carbazole) (o-mCPBI), 9,9'-(3'-(1H-benzimidazol-1-yl)-[1,1'-biphenyl]-3,5-diyl)bis(9H-carbazole) (m-mCPBI), and 9,9'-(4'-(1H-benzimidazol-1-yl)-[1,1'-biphenyl]-3,5-diyl)bis(9H-carbazole) (p-mCPBI), are designed and synthesized by integrating mCP with benzimidazole moiety via the ortho-, meta-, and para-positions of N-phenyl. The influence of different linking modes on the thermal, photophysical, electrochemical, and charge transport properties of the compounds is studied. By employing the same device structure except the emitting layer, the device performances of the blue, green, yellow, red, white phosphorescent and blue, green TADF organic light-emitting diodes (OLEDs) based on the three hosts are investigated. Among these three hosts, o-mCPBI exhibits the best device performance with external quantum efficiencies of over 20% for phosphorescent OLEDs and enhanced efficiencies for TADF devices. All these devices show relatively low efficiency roll-offs at high brightness. The versatility of the benzimidazole-based bipolar host o-mCPBI, such as an extremely high triplet energy level, suitable molecular orbital energy levels, improved thermal and charge transport properties, and excellent device performances for various colors, makes it a universal host material for highly efficient both phosphorescent and TADF OLEDs.

  1. Evolution of Defect Structures and Deep Subgap States during Annealing of Amorphous In-Ga-Zn Oxide for Thin-Film Transistors

    Science.gov (United States)

    Jia, Junjun; Suko, Ayaka; Shigesato, Yuzo; Okajima, Toshihiro; Inoue, Keiko; Hosomi, Hiroyuki

    2018-01-01

    We investigate the evolution behavior of defect structures and the subgap states in In-Ga-Zn oxide (IGZO) films with increasing postannealing temperature by means of extended x-ray absorption fine-structure (EXAFS) measurements, positron annihilation lifetime spectroscopy (PALS), and cathodoluminescence (CL) spectroscopy, aiming to understand the relationship between defect structures and subgap states. EXAFS measurements reveal the varied oxygen coordination numbers around cations during postannealing and confirm two types of point defects, namely, excess oxygen around Ga atoms and oxygen deficiency around In and/or Zn atoms. PALS suggests the existence of cation-vacancy (VM )-related clusters with neutral or negative charge in both amorphous and polycrystalline IGZO films. CL spectra show a main emission band at approximately 1.85 eV for IGZO films, and a distinct shoulder located at about 2.15 eV for IGZO films postannealed above 600 °C . These two emission bands are assigned to a recombination between the electrons in the conduction band and/or in the shallow donor levels near the conduction band and the acceptors trapped above the valence-band maximum. The shallow donors are attributed to the oxygen deficiency, and the acceptors are thought to possibly arise from the excess oxygen or the VM-related clusters. These results open up an alternative route for understanding the device instability of amorphous IGZO-based thin-film transistors, especially the presence of the neutral or negatively charged VM-related clusters in amorphous IGZO films.

  2. Transistor-based interface circuitry

    Science.gov (United States)

    Taubman, Matthew S [Richland, WA

    2004-02-24

    Among the embodiments of the present invention is an apparatus that includes a transistor, a servo device, and a current source. The servo device is operable to provide a common base mode of operation of the transistor by maintaining an approximately constant voltage level at the transistor base. The current source is operable to provide a bias current to the transistor. A first device provides an input signal to an electrical node positioned between the emitter of the transistor and the current source. A second device receives an output signal from the collector of the transistor.

  3. Experimental synchronization of chaos in a large ring of mutually coupled single-transistor oscillators: Phase, amplitude, and clustering effects

    Science.gov (United States)

    Minati, Ludovico

    2014-12-01

    In this paper, experimental evidence of multiple synchronization phenomena in a large (n = 30) ring of chaotic oscillators is presented. Each node consists of an elementary circuit, generating spikes of irregular amplitude and comprising one bipolar junction transistor, one capacitor, two inductors, and one biasing resistor. The nodes are mutually coupled to their neighbours via additional variable resistors. As coupling resistance is decreased, phase synchronization followed by complete synchronization is observed, and onset of synchronization is associated with partial synchronization, i.e., emergence of communities (clusters). While component tolerances affect community structure, the general synchronization properties are maintained across three prototypes and in numerical simulations. The clusters are destroyed by adding long distance connections with distant notes, but are otherwise relatively stable with respect to structural connectivity changes. The study provides evidence that several fundamental synchronization phenomena can be reliably observed in a network of elementary single-transistor oscillators, demonstrating their generative potential and opening way to potential applications of this undemanding setup in experimental modelling of the relationship between network structure, synchronization, and dynamical properties.

  4. Hafnium transistor design for neural interfacing.

    Science.gov (United States)

    Parent, David W; Basham, Eric J

    2008-01-01

    A design methodology is presented that uses the EKV model and the g(m)/I(D) biasing technique to design hafnium oxide field effect transistors that are suitable for neural recording circuitry. The DC gain of a common source amplifier is correlated to the structural properties of a Field Effect Transistor (FET) and a Metal Insulator Semiconductor (MIS) capacitor. This approach allows a transistor designer to use a design flow that starts with simple and intuitive 1-D equations for gain that can be verified in 1-D MIS capacitor TCAD simulations, before final TCAD process verification of transistor properties. The DC gain of a common source amplifier is optimized by using fast 1-D simulations and using slower, complex 2-D simulations only for verification. The 1-D equations are used to show that the increased dielectric constant of hafnium oxide allows a higher DC gain for a given oxide thickness. An additional benefit is that the MIS capacitor can be employed to test additional performance parameters important to an open gate transistor such as dielectric stability and ionic penetration.

  5. Preparation of bipolar membranes by electrospinning

    International Nuclear Information System (INIS)

    Pan, Jiefeng; Hou, Linxiao; Wang, Qiuyue; He, Yubin; Wu, Liang; Mondal, Abhishek N.; Xu, Tongwen

    2017-01-01

    A new preparative pathway for the bipolar membranes was initiated via the electrospinning and hot-press process. The prepared bipolar membrane was consisting of sulfonated poly (phenylene oxide), polyethylene glycol, and quaternized poly (phenylene oxide). The above mentioned membrane was fabricated by the continuous electrospinning of the respective layer, followed by the solvent atmosphere treatment and hot-pressing, to obtain a transparent and dense structure. The thickness of each layer can be easily tuned by controlling the electrospinning parameters. The clear interfacial structure was observed and confirmed by the scanning electron microscope. The bipolar performance is evaluated by the current–voltage curves and production yield of acid and base. The final optimized bipolar membrane had similar yield of acid and base as the casting membrane. However, extremely lower potential drop value was observed when they are applied for the production of acid and base. The experimental results showed that, electrospinning is an effective and well controlled way to fabricate bipolar membranes, in which anion or cation exchange layer as well as interfacial layer can be easily changed or added as requested. - Highlights: • Bipolar membranes were prepared through electrospinning followed by post-treatment. • As-prepared membranes were successfully applied in electrodialysis for production of acid and base. • Electrospun membranes exhibit better performance than the casting ones.

  6. Preparation of bipolar membranes by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Jiefeng; Hou, Linxiao; Wang, Qiuyue; He, Yubin; Wu, Liang; Mondal, Abhishek N.; Xu, Tongwen, E-mail: twxu@ustc.edu.cn

    2017-01-15

    A new preparative pathway for the bipolar membranes was initiated via the electrospinning and hot-press process. The prepared bipolar membrane was consisting of sulfonated poly (phenylene oxide), polyethylene glycol, and quaternized poly (phenylene oxide). The above mentioned membrane was fabricated by the continuous electrospinning of the respective layer, followed by the solvent atmosphere treatment and hot-pressing, to obtain a transparent and dense structure. The thickness of each layer can be easily tuned by controlling the electrospinning parameters. The clear interfacial structure was observed and confirmed by the scanning electron microscope. The bipolar performance is evaluated by the current–voltage curves and production yield of acid and base. The final optimized bipolar membrane had similar yield of acid and base as the casting membrane. However, extremely lower potential drop value was observed when they are applied for the production of acid and base. The experimental results showed that, electrospinning is an effective and well controlled way to fabricate bipolar membranes, in which anion or cation exchange layer as well as interfacial layer can be easily changed or added as requested. - Highlights: • Bipolar membranes were prepared through electrospinning followed by post-treatment. • As-prepared membranes were successfully applied in electrodialysis for production of acid and base. • Electrospun membranes exhibit better performance than the casting ones.

  7. Modeling of enclosed-gate layout transistors as ESD protection device based on conformal mapping method

    International Nuclear Information System (INIS)

    Zhang Jia; Yang Haigang; Sun Jiabin; Yu Le; Wei Yuanfeng

    2014-01-01

    This paper proposes a novel technique for modeling the electrostatic discharge (ESD) characteristic of the enclosed-gate layout transistors (ELTs). The model consists of an ELT, a parasitic bipolar transistor, and a substrate resistor. The ELT is decomposed into edge and corner transistors by solving the electrostatic field problem through the conformal mapping method, and these transistors are separately modeled by BSIM (Berkeley Short-channel IGFET Model). Fast simulation speed and easy implementation is obtained as the model can be incorporated into standard SPICE simulation. The model parameters are extracted from the critical point of the snapback curve, and simulation results are presented and compared to experimental data for verification. (semiconductor integrated circuits)

  8. Study of improved reverse recovery in power transistor incorporating universal contact

    Science.gov (United States)

    Anand, R. S.; Mazhari, B.; Narain, J.

    2004-05-01

    The improvement in reverse recovery of power NPN bipolar transistor (BJT) through incorporation of "universal contact" in the base is studied in detail. It is shown that use of universal contact allows redistribution of base current in saturation from collector region where recombination lifetime is high to extrinsic base region where effective recombination lifetime is low. The reverse recovery time decreases as collector current density increases but increases as collector breakdown voltage increases. The improvement in reverse recovery is accompanied with an increase in collector-emitter voltage in the ON state. For low voltage transistors and high voltage transistors at low collector current densities, the increase is primarily due to reduction in reverse current gain. For high breakdown voltage transistors, the use of universal contact results in early onset of quasi-saturation effect and results in degradation in ON state voltage at high collector current densities.

  9. Characterization of interface states in Al2O3/AlGaN/GaN structures for improved performance of high-electron-mobility transistors

    International Nuclear Information System (INIS)

    Hori, Y.; Yatabe, Z.; Hashizume, T.

    2013-01-01

    We have investigated the relationship between improved electrical properties of Al 2 O 3 /AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs) and electronic state densities at the Al 2 O 3 /AlGaN interface evaluated from the same structures as the MOS-HEMTs. To evaluate Al 2 O 3 /AlGaN interface state densities of the MOS-HEMTs, two types of capacitance-voltage (C-V) measurement techniques were employed: the photo-assisted C-V measurement for the near-midgap states and the frequency dependent C-V characteristics for the states near the conduction-band edge. To reduce the interface states, an N 2 O-radical treatment was applied to the AlGaN surface just prior to the deposition of the Al 2 O 3 insulator. As compared to the sample without the treatment, the N 2 O-radical treated Al 2 O 3 /AlGaN/GaN structure showed smaller frequency dispersion of the C-V curves in the positive gate bias range. The state densities at the Al 2 O 3 /AlGaN interface were estimated to be 1 × 10 12  cm −2  eV −1 or less around the midgap and 8 × 10 12  cm −2  eV −1 near the conduction-band edge. In addition, we observed higher maximum drain current at the positive gate bias and suppressed threshold voltage instability under the negative gate bias stress even at 150 °C. Results presented in this paper indicated that the N 2 O-radical treatment is effective both in reducing the interface states and improving the electrical properties of the Al 2 O 3 /AlGaN/GaN MOS-HEMTs

  10. Characterization of interface states in Al2O3/AlGaN/GaN structures for improved performance of high-electron-mobility transistors

    Science.gov (United States)

    Hori, Y.; Yatabe, Z.; Hashizume, T.

    2013-12-01

    We have investigated the relationship between improved electrical properties of Al2O3/AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs) and electronic state densities at the Al2O3/AlGaN interface evaluated from the same structures as the MOS-HEMTs. To evaluate Al2O3/AlGaN interface state densities of the MOS-HEMTs, two types of capacitance-voltage (C-V) measurement techniques were employed: the photo-assisted C-V measurement for the near-midgap states and the frequency dependent C-V characteristics for the states near the conduction-band edge. To reduce the interface states, an N2O-radical treatment was applied to the AlGaN surface just prior to the deposition of the Al2O3 insulator. As compared to the sample without the treatment, the N2O-radical treated Al2O3/AlGaN/GaN structure showed smaller frequency dispersion of the C-V curves in the positive gate bias range. The state densities at the Al2O3/AlGaN interface were estimated to be 1 × 1012 cm-2 eV-1 or less around the midgap and 8 × 1012 cm-2 eV-1 near the conduction-band edge. In addition, we observed higher maximum drain current at the positive gate bias and suppressed threshold voltage instability under the negative gate bias stress even at 150 °C. Results presented in this paper indicated that the N2O-radical treatment is effective both in reducing the interface states and improving the electrical properties of the Al2O3/AlGaN/GaN MOS-HEMTs.

  11. Effect of active-layer composition and structure on device performance of coplanar top-gate amorphous oxide thin-film transistors

    Science.gov (United States)

    Yue, Lan; Meng, Fanxin; Chen, Jiarong

    2018-01-01

    The thin-film transistors (TFTs) with amorphous aluminum-indium-zinc-oxide (a-AIZO) active layer were prepared by dip coating method. The dependence of properties of TFTs on the active-layer composition and structure was investigated. The results indicate that Al atoms acted as a carrier suppressor in IZO films. Meanwhile, it was found that the on/off current ratio (I on/off) of TFT was improved by embedding a high-resistivity AIZO layer between the low-resistivity AIZO layer and gate insulator. The improvement in I on/off was attributed to the decrease in off-state current of double-active-layer TFT due to an increase in the active-layer resistance and the contact resistance between active layer and source/drain electrode. Moreover, on-state current and threshold voltage (V th) can be mainly controlled through thickness and Al content of the low-resistivity AIZO layer. In addition, the saturation mobility (μ sat) of TFTs was improved with reducing the size of channel width or/and length, which was attributed to the decrease in trap states in the semiconductor and at the semiconductor/gate-insulator interface with the smaller channel width or/and shorter channel length. Thus, we can demonstrate excellent TFTs via the design of active-layer composition and structure by utilizing a low cost solution-processed method. The resulting TFT, operating in enhancement mode, has a high μ sat of 14.16 cm2 V‑1 s‑1, a small SS of 0.40 V/decade, a close-to-zero V th of 0.50 V, and I on/off of more than 105.

  12. Sleep study in Disruptive Mood Dysregulation Disorder and Bipolar children.

    Science.gov (United States)

    Estrada-Prat, Xavier; Álvarez-Guerrico, Ion; Bleda-Hernández, María J; Camprodon-Rosanas, Ester; Batlle-Vila, Santiago; Pujals-Altes, Elena; Nascimento-Osorio, María T; Martín-López, Luís M; Álvarez-Martínez, Enric; Pérez-Solá, Víctor; Romero-Cela, Soledad

    2017-01-01

    Decreased need for sleep has been proposed as a core symptom of mania and it has been associated with the pathogenesis of Bipolar Disorder. The emergence of Disruptive Mood Dysregulation Disorder (DMDD) as a new diagnostic has been controversial and much has been speculated about its relationship with the bipolar spectrum. REM sleep fragmentation could be a biomarker of affective disorders and it would help us to differentiate them from other disorders. Polysomnographic cross-sectional study of children with DMDD, bipolar disorder and Attention Deficit Hyperactivity Disorder (ADHD). All participants underwent a psychiatric semi-structured interview to obtain the diagnosis, comorbidities and primary sleep disorders. DMDD’s sample was performed following DSM5 criteria. Perform polysomnography in a sample of bipolar, DMDD and ADHD children and compare their profiles to provide more evidence about the differences or similarities between bipolar disorder and DMDD. Bipolar group had the highest REM density values while ADHD had the lowest. REM density was not statiscally different between bipolar phenotypes. REM density was associated with antidepressant treatment, episodes of REM and their interaction. REM latency was associated with antipsychotic treatment and school performance. Bipolar patients had higher scores on the depression scale than DMDD and ADHD groups. No significant differences between the two compared affective disorders were found. However there were differences in REM density between bipolar and ADHD groups. REM sleep study could provide a new theoretical framework to better understand the pathogenesis of pediatric bipolar disorder.

  13. Graphene Field Effect Transistor for Radiation Detection

    Science.gov (United States)

    Li, Mary J. (Inventor); Chen, Zhihong (Inventor)

    2016-01-01

    The present invention relates to a graphene field effect transistor-based radiation sensor for use in a variety of radiation detection applications, including manned spaceflight missions. The sensing mechanism of the radiation sensor is based on the high sensitivity of graphene in the local change of electric field that can result from the interaction of ionizing radiation with a gated undoped silicon absorber serving as the supporting substrate in the graphene field effect transistor. The radiation sensor has low power and high sensitivity, a flexible structure, and a wide temperature range, and can be used in a variety of applications, particularly in space missions for human exploration.

  14. Fundamentals of nanoscaled field effect transistors

    CERN Document Server

    Chaudhry, Amit

    2013-01-01

    Fundamentals of Nanoscaled Field Effect Transistors gives comprehensive coverage of the fundamental physical principles and theory behind nanoscale transistors. The specific issues that arise for nanoscale MOSFETs, such as quantum mechanical tunneling and inversion layer quantization, are fully explored. The solutions to these issues, such as high-κ technology, strained-Si technology, alternate devices structures and graphene technology are also given. Some case studies regarding the above issues and solution are also given in the book. In summary, this book: Covers the fundamental principles behind nanoelectronics/microelectronics Includes chapters devoted to solutions tackling the quantum mechanical effects occurring at nanoscale Provides some case studies to understand the issue mathematically Fundamentals of Nanoscaled Field Effect Transistors is an ideal book for researchers and undergraduate and graduate students in the field of microelectronics, nanoelectronics, and electronics.

  15. Crossed Andreev reflection in a graphene bipolar transistor.

    Science.gov (United States)

    Cayssol, J

    2008-04-11

    We investigate the crossed Andreev reflections between two graphene leads connected by a narrow superconductor. When the leads are, respectively, of the n and p type, we find that electron elastic cotunneling and local Andreev reflection are both eliminated even in the absence of any valley-isospin or spin polarizations. We further predict oscillations of both diagonal and cross conductances as a function of the distance between the graphene-superconductor interfaces.

  16. Heuristic for Learning Common Emitter Amplification with Bipolar Transistors

    Science.gov (United States)

    Staffas, Kjell

    2017-01-01

    Mathematics in engineering education causes many thresholds in the courses because of the demand of abstract conceptualisation. Electronics depend heavily on more or less complex mathematics. Therefore the concepts of analogue electronics are hard to learn since a great deal of students struggle with the calculations and procedures needed. A…

  17. Soft switch-avalanche IGBT convertor. [Insulated Gate Bipolar Transistor

    Science.gov (United States)

    Chen, K.; Stuart, T. A.

    1990-01-01

    A full bridge dc-dc converter using a zero voltage and zero current switching technique is described. This circuit utilizes the characteristics of the IGBT to achieve power and frequency combinations that are much higher than those previously reported for this device. Experimental results are included for a 1.5 kW, 100 kHz converter with 94 percent efficiency.

  18. Development of insulated gate bipolar transistor-based power ...

    Indian Academy of Sciences (India)

    [5] S V Nakhe et al, National Laser Symposium, 81–82 (2001). [6] E G Cook et al, 8th IEEE Pulsed Power Conference, June 1991. [7] L Druckmann et al, IEEE Power Modulator Symposium, 213–216 (1992). [8] Hybrid gate drivers and gate drive power supplies, M57962L datasheet from Mitsubishi. Electric Corpn. Pramana ...

  19. Development of insulated gate bipolar transistor-based power ...

    Indian Academy of Sciences (India)

    325 V to 550 V with a maximum current rating of 20 A. The storage capacitor is realized using two capacitor banks C01 and C02. These capacitor banks are reso- nantly charged through the charging inductor Lc, blocking diode Db and primary of the pulse transformer by the DC source to approximately twice its value. Pulse.

  20. Genetics of bipolar disorder.

    Science.gov (United States)

    Kerner, Berit

    2014-01-01

    Bipolar disorder is a common, complex genetic disorder, but the mode of transmission remains to be discovered. Many researchers assume that common genomic variants carry some risk for manifesting the disease. The research community has celebrated the first genome-wide significant associations between common single nucleotide polymorphisms (SNPs) and bipolar disorder. Currently, attempts are under way to translate these findings into clinical practice, genetic counseling, and predictive testing. However, some experts remain cautious. After all, common variants explain only a very small percentage of the genetic risk, and functional consequences of the discovered SNPs are inconclusive. Furthermore, the associated SNPs are not disease specific, and the majority of individuals with a "risk" allele are healthy. On the other hand, population-based genome-wide studies in psychiatric disorders have rediscovered rare structural variants and mutations in genes, which were previously known to cause genetic syndromes and monogenic Mendelian disorders. In many Mendelian syndromes, psychiatric symptoms are prevalent. Although these conditions do not fit the classic description of any specific psychiatric disorder, they often show nonspecific psychiatric symptoms that cross diagnostic boundaries, including intellectual disability, behavioral abnormalities, mood disorders, anxiety disorders, attention deficit, impulse control deficit, and psychosis. Although testing for chromosomal disorders and monogenic Mendelian disorders is well established, testing for common variants is still controversial. The standard concept of genetic testing includes at least three broad criteria that need to be fulfilled before new genetic tests should be introduced: analytical validity, clinical validity, and clinical utility. These criteria are currently not fulfilled for common genomic variants in psychiatric disorders. Further work is clearly needed before genetic testing for common variants in

  1. Bipolar Disorder - Multiple Languages

    Science.gov (United States)

    ... MP3 Bipolar Disorder (An Introduction) - English MP4 Bipolar Disorder (An Introduction) - español (Spanish) MP4 Healthy Roads Media Characters not displaying correctly on this page? See language display issues . Return to the MedlinePlus Health Information ...

  2. BN / Graphene / BN RF Transistors

    Science.gov (United States)

    Wang, Han; Taychatanapat, Thiti; Hsu, Allen; Jarillo-Herrero, Pablo; Palacios, Tomas

    2011-03-01

    In this work we demonstrate the first BN/graphene/BN transistor for high frequency RF applications. This sandwich structure allows a significant improvement in the mobility of graphene, which reaches more than 18,000 cm2 /Vs at room temperature. Graphene field effect transistors (GFETs) have been fabricated with LDS = 800 nm and LG = 300 nm. The minimum conduction point of these devices is very close to zero, a result of the negligible substrate doping to the graphene. A current density in excess of 1 A/mm and DC transconductance above 200 mS/mm are achieved for both electron and hole conductions. RF characterization is performed for the first time on this device structure and initial results show a current-gain cut-off frequency fT = 10 GHz. These experimental results have been combined with simulations of the small-signal model to study the scaling potential of these GFETs for high frequency applications. The impact of the access resistances (Rs , Rd) , the capacitances (Cgs , Cgd , Cds) , and the transconductance (g m) on the frequency performance of the GFETs has also been studied. Finally, the fabricated devices have been compared to GFETs fabricated with Si O2 substrate and Al 2 O3 gate dielectrics. The improved performance obtained by the BN/graphene/BN structure is very promising to enable the next generation of high frequency RF electronics.

  3. The impact of the CACNA1C risk allele on limbic structures and facial emotions recognition in bipolar disorder subjects and healthy controls.

    Science.gov (United States)

    Soeiro-de-Souza, Márcio Gerhardt; Otaduy, Maria Concepción Garcia; Dias, Carolina Zadres; Bio, Danielle S; Machado-Vieira, Rodrigo; Moreno, Ricardo Alberto

    2012-12-01

    Impairments in facial emotion recognition (FER) have been reported in bipolar disorder (BD) during all mood states. FER has been the focus of functional magnetic resonance imaging studies evaluating differential activation of limbic regions. Recently, the α1-C subunit of the L-type voltage-gated calcium channel (CACNA1C) gene has been described as a risk gene for BD and its Met allele found to increase CACNA1C mRNA expression. In healthy controls, the CACNA1C risk (Met) allele has been reported to increase limbic system activation during emotional stimuli and also to impact on cognitive function. The aim of this study was to investigate the impact of CACNA1C genotype on FER scores and limbic system morphology in subjects with BD and healthy controls. Thirty-nine euthymic BD I subjects and 40 healthy controls were submitted to a FER recognition test battery and genotyped for CACNA1C. Subjects were also examined with a 3D 3-Tesla structural imaging protocol. The CACNA1C risk allele for BD was associated to FER impairment in BD, while in controls nothing was observed. The CACNA1C genotype did not impact on amygdala or hippocampus volume neither in BD nor controls. Sample size. The present findings suggest that a polymorphism in calcium channels interferes FER phenotype exclusively in BD and doesn't interfere on limbic structures morphology. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. Classification of cognitive performance in bipolar disorder.

    Science.gov (United States)

    Sparding, Timea; Silander, Katja; Pålsson, Erik; Östlind, Josefin; Ekman, Carl Johan; Sellgren, Carl M; Joas, Erik; Hansen, Stefan; Landén, Mikael

    2017-09-01

    To understand the etiology of cognitive impairment associated with bipolar disorder, we need to clarify potential heterogeneity in cognitive functioning. To this end, we used multivariate techniques to study if the correlation structure of cognitive abilities differs between persons with bipolar disorder and controls. Clinically stable patients with bipolar disorder (type I: n = 64; type II: n = 44) and healthy controls (n = 86) were assessed with a wide range of cognitive tests measuring executive function, speed, memory, and verbal skills. Data were analysed with multivariate techniques. A distinct subgroup (∼30%) could be identified that performed significantly poorer on tests concerning memory function. This cognitive phenotype subgroup did not differ from the majority of bipolar disorder patients with respect to other demographic or clinical characteristics. Whereas the majority of patients performed similar to controls, a subgroup of patients with bipolar disorder differed substantially from healthy controls in the correlation pattern of low-level cognitive abilities. This suggests that cognitive impairment is not a general trait in bipolar disorder but characteristic of a cognitive subgroup. This has important clinical implications for cognitive rehabilitation and remediation.

  5. "Is it menopause or bipolar?": a qualitative study of the experience of menopause for women with bipolar disorder.

    Science.gov (United States)

    Perich, Tania; Ussher, Jane; Parton, Chloe

    2017-11-16

    Menopause can be a time of change for women and may be marked by disturbances in mood. For women living with a mental illness, such as bipolar disorder, little is known about how they experience mood changes during menopause. This study aimed to explore how women with bipolar disorder constructed mood changes during menopause and how this impacted on treatment decisions. Semi-structured interviews were undertaken with fifteen women who reported they had been diagnosed with bipolar disorder. Data was analysed using thematic analysis guided by a social constructionist framework. Themes identified included 'Constructions of mood change: menopause or bipolar disorder?',' Life events, bipolar disorder and menopause coming together'; 'Treatment choices for mood change during menopause'. The accounts suggested that women related to the experience of mood changes during menopause through the lens of their existing framework of bipolar disorder, with implications for understanding of self and treatment choices.

  6. Properties of Bipolar Fuzzy Hypergraphs

    OpenAIRE

    Akram, M.; Dudek, W. A.; Sarwar, S.

    2013-01-01

    In this article, we apply the concept of bipolar fuzzy sets to hypergraphs and investigate some properties of bipolar fuzzy hypergraphs. We introduce the notion of $A-$ tempered bipolar fuzzy hypergraphs and present some of their properties. We also present application examples of bipolar fuzzy hypergraphs.

  7. High current gain silicon-based spin transistor

    CERN Document Server

    Dennis, C L; Ensell, G J; Gregg, J F; Thompson, S M

    2003-01-01

    A silicon-based spin transistor of novel operating principle has been demonstrated in which the current gain at room temperature is 1.4 (n-type) and 0.97 (p-type). This high current gain was obtained from a hybrid metal/semiconductor analogue to the bipolar junction transistor which functions by tunnel-injecting carriers from a ferromagnetic emitter into a diffusion driven silicon base and then tunnel-collecting them via a ferromagnetic collector. The switching of the magnetic state of the collector ferromagnet controls the collector efficiency and the current gain. Furthermore, the magnetocurrent, which is determined to be 98% (140%) for p-type (n-type) in -110 Oe, is attributable to the spin-polarized base diffusion current.

  8. A study of genetic and environmental contributions to structural brain changes over time in twins concordant and discordant for bipolar disorder.

    Science.gov (United States)

    Bootsman, F; Brouwer, R M; Schnack, H G; Kemner, S M; Hillegers, M H J; Sarkisyan, G; van der Schot, A C; Vonk, R; Hulshoff Pol, H E; Nolen, W A; Kahn, R S; van Haren, N E M

    2016-08-01

    This is the first longitudinal twin study examining genetic and environmental contributions to the association between liability to bipolar disorder (BD) and changes over time in global brain volumes, and global and regional measures of cortical surface area, cortical thickness and cortical volume. A total of 50 twins from pairs discordant or concordant for BD (monozygotic: 8 discordant and 3 concordant pairs, and 1 patient and 3 co-twins from incomplete pairs; dizygotic: 6 discordant and 2 concordant pairs, and 1 patient and 7 co-twins from incomplete pairs) underwent magnetic resonance imaging twice. In addition, 57 twins from healthy twin pairs (15 monozygotic and 10 dizygotic pairs, and 4 monozygotic and 3 dizygotic subjects from incomplete pairs) were also scanned twice. Mean follow-up duration for all twins was 7.5 years (standard deviation: 1.5 years). Data were analyzed using structural equation modeling software OpenMx. The liability to BD was not associated with global or regional structural brain changes over time. Although we observed a subtle increase in cerebral white matter in BD patients, this effect disappeared after correction for multiple comparisons. Heritability of brain changes over time was generally low to moderate. Structural brain changes appear to follow similar trajectories in BD patients and healthy controls. Existing brain abnormalities in BD do not appear to progressively change over time, but this requires additional confirmation. Further study with large cohorts is recommended to assess genetic and environmental influences on structural brain abnormalities in BD, while taking into account the influence of lithium on the brain. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Electrical-field-induced structural change and charge transfer of lanthanide-salophen complexes assembled on carbon nanotube field effect transistor devices.

    OpenAIRE

    Magadur , Gurvan; Bouanis , Fatima Zara; Norman , Evgeny; Guillot , Regis; Lauret , Jean Sebastien; Huc , Vincent; Cojocaru , Costel Sorin; Mallah , Talal

    2012-01-01

    International audience; The application of a negative gate voltage on a carbon nanotube field effect transistor decorated by a binuclear Tb(III) complex leads to the generation of a negatively charged mononuclear one, presenting an electron density transfer to the nanotube and ambipolar behaviour.

  10. Bipolar Disorder in Children

    Science.gov (United States)

    2014-01-01

    Although bipolar disorder historically was thought to only occur rarely in children and adolescents, there has been a significant increase in children and adolescents who are receiving this diagnosis more recently (Carlson, 2005). Nonetheless, the applicability of the current bipolar disorder diagnostic criteria for children, particularly preschool children, remains unclear, even though much work has been focused on this area. As a result, more work needs to be done to further the understanding of bipolar symptoms in children. It is hoped that this paper can assist psychologists and other health service providers in gleaning a snapshot of the literature in this area so that they can gain an understanding of the diagnostic criteria and other behaviors that may be relevant and be informed about potential approaches for assessment and treatment with children who meet bipolar disorder criteria. First, the history of bipolar symptoms and current diagnostic criteria will be discussed. Next, assessment strategies that may prove helpful for identifying bipolar disorder will be discussed. Then, treatments that may have relevance to children and their families will be discussed. Finally, conclusions regarding work with children who may have a bipolar disorder diagnosis will be offered. PMID:24800202

  11. Bipolar Disorder in Children

    Directory of Open Access Journals (Sweden)

    Kimberly Renk

    2014-01-01

    Full Text Available Although bipolar disorder historically was thought to only occur rarely in children and adolescents, there has been a significant increase in children and adolescents who are receiving this diagnosis more recently (Carlson, 2005. Nonetheless, the applicability of the current bipolar disorder diagnostic criteria for children, particularly preschool children, remains unclear, even though much work has been focused on this area. As a result, more work needs to be done to further the understanding of bipolar symptoms in children. It is hoped that this paper can assist psychologists and other health service providers in gleaning a snapshot of the literature in this area so that they can gain an understanding of the diagnostic criteria and other behaviors that may be relevant and be informed about potential approaches for assessment and treatment with children who meet bipolar disorder criteria. First, the history of bipolar symptoms and current diagnostic criteria will be discussed. Next, assessment strategies that may prove helpful for identifying bipolar disorder will be discussed. Then, treatments that may have relevance to children and their families will be discussed. Finally, conclusions regarding work with children who may have a bipolar disorder diagnosis will be offered.

  12. Neurocognitive and Neuroimaging Predictors of Clinical Outcome in Bipolar Disorder

    OpenAIRE

    Bearden, Carrie E.; Woogen, Michelle; Glahn, David C.

    2010-01-01

    Historically, bipolar disorder has been conceptualized as a disease involving episodic rather than chronic dysfunction. However, increasing evidence indicates that bipolar disorder is associated with substantial inter-episode psychosocial and vocational impairment. Here we review the contributions of neurocognitive deficits and structural and functional neuroanatomic alterations to the observed functional impairments. In particular, compelling evidence now suggests that neurocognitive impairm...

  13. Theoretical investigations of the electronic structures of carbazole-based triphenylphosphine oxide derivatives, potential bipolar host materials in blue-phosphorescent devices.

    Science.gov (United States)

    Sun, Huili; Shen, Wei; Zhang, Xiaguang; Zhang, Dongmei; Li, Ming

    2015-12-01

    Density functional theory calculations were performed to investigate the electronic structures of bipolar host materials comprising a backbone of linked acceptor moieties where each acceptor was also linked to a pendant donor moiety. The acceptor was triphenylphosphine oxide with two of its phenyls substituted with fluorine atoms or nitrile groups (CN). The donor was carbazole (CZ) substituted, or not, with t-butyl groups. The HOMO and LUMO energy levels of these host molecules were mainly influenced by their respective hole- and electron-transport units. The t-butyl substituents on the CZ moieties had an adverse effect on the triplet energies (E T) of the host molecules, especially for molecules where the phenyls of the backbone chain were substituted with CN groups. While introducing CN substituents onto the backbone chain decreased the energy difference between the lowest singlet and triplet excited states (ΔE ST), it also caused the energy gap between the HOMO and LUMO to narrow. Among the host molecules investigated, that in which one of the phenyls in the acceptor moiety was linked to the donor while the other two phenyls in the acceptor were substituted with CN substituents exhibited the highest E T, balanced charge transport, a low charge-injection barrier, and a small ΔE ST, and is therefore a promising candidate host material for use in blue-phosphorescent devices. Graphical Abstract Density functional theory calculations were performed to explore the electronic properties of bipolar host materials comprising a backbone of linked acceptor moieties where each acceptor was also linked to a pendant donor moiety. All of the designed molecules with high triplet energies were found to be suitable for use as host materials when matched with a blue-light guest material. The results demonstrate that the host molecule in which one of the phenyls in the triphenylphosphine oxide acceptor moiety was linked to the carbazole donor while the other two phenyls in the

  14. Structure-Processing Relationships in Solution Processable Polymer Thin Film Transistors and Small Molecule Bulk Heterojunction Solar Cells

    Science.gov (United States)

    Perez, Louis A.

    A regio-regular (RR) conjugated copolymer based on cyclopenta[2,1-b:3,4- b]dithiophene (CDT) and pyridal[2,1,3]thiadiazole (PT) structural units was prepared by using polymerization reactions involving reactants specifically designed to avoid random orientation of the asymmetric PT heterocycle. Compared to its regio-irregular (RI) counterpart, the RR polymer exhibits a two orders of magnitude increase in hole mobility from 0.005 to 0.6 cm2V -1s-1. To probe the reason for this difference in mobility, we examined the crystalline structure and its orientation in thin films of both copolymers as a function of depth via grazing incidence wide angle X-ray scattering (GIWAXS). In the RI film, the pi-pi stacking direction of the crystallites is mainly perpendicular to the substrate normal (edge-on orientation) while in the RR film the crystallites adopt a mixed pi-pi stacking orientation in the center of the film as well as near the interface between the polymer and the dielectric layer. These results demonstrate that control of backbone regularity is another important design criterion to consider in the synthesis and optimization of new conjugated copolymers with asymmetric structural units. Solution processed organic photovoltaic devices (OPVs) have emerged as a promising sustainable energy technology due to their ease of fabrication, potential to enable low-cost manufacturing, and ability to be incorporated onto light-weight flexible substrates. To date, the most efficacious OPV device architecture, the bulk heterojunction (BHJ), consists of a blend of a light-harvesting conjugated organic electron donating molecule and a strong electron-accepting compound (usually a soluble fullerene derivative e.g. [6,6]-phenyl C71 butyric acid methyl ester (PC71BM). BHJ layer morphology, which has been shown to be highly dependent on processing, has a significant effect on OPV performance. It is postulated that optimal BHJ morphologies consist of discrete bicontinuous nanoscale

  15. Discharge dynamics of self-oriented microplasma coupling between cross adjacent cavities in micro-structure device driven by a bipolar pulse waveform

    Science.gov (United States)

    Wang, Yaogong; Zhang, Xiaoning; Liu, Lingguang; Zhou, Xuan; Liu, Chunliang; Zhang, Qiaogen

    2018-04-01

    The excitation dynamics and self-oriented plasma coupling of a micro-structure plasma device with a rectangular cross-section are investigated. The device consists of 7 × 7 microcavity arrays, which are blended into a unity by a 50 μm-thick bulk area above them. The device is operated in argon with a pressure of 200 Torr, driven by a bipolar pulse waveform of 20 kHz. The discharge evolution is characterized by means of electrical measurements and optical emission profiles. It has been found that different emission patterns are observed within microcavities. The formation of these patterns induced by the combined action between the applied electric field and surface deactivation is discussed. The microplasma distribution in some specific regions along the diagonal direction of cavities in the bulk area is observed, and self-oriented microplasma coupling is explored, while the plasma interaction occurred between cross adjacent cavities, contributed by the ionization wave propagation. The velocity of ionization wave propagation is measured to be 1.2 km/s to 3.5 km/s. The exploration of this plasma interaction in the bulk area is of value to applications in electromagnetics and signal processing.

  16. Effect of 100MeV oxygen ion irradiation on silicon NPN power transistor

    Science.gov (United States)

    Kumar, M. Vinay; Krishnakumar, K. S.; Dinesh, C. M.; Krishnaveni, S.; Ramani

    2012-06-01

    The radiation response of npn Bipolar junction transistor (BJT) has been examined for 100 MeV O7+ ion. Key electrical properties like Gummel characteristics, dc current gain and capacitance-voltage of 100MeV O7+ ion irradiated transistor were studied before and after irradiation. The device was decapped and the electrical characterizations were performed at room temperature. Base current is observed to be more sensitive than collector current and gain appears to be degraded with ion fluence, also considerable degradation in C-V characteristics is observed and doping concentration is found to be increased along with the increase in ion fluence.

  17. Effect of 100MeV oxygen ion irradiation on silicon NPN power transistor

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M. Vinay; Krishnakumar, K. S.; Dinesh, C. M.; Krishnaveni, S.; Ramani [Department of studies in Physics, University of Mysore, Mysore (India); Department of Physics, APS College, Bengaluru (India); Department of Physics, DCE, Govt. First Grade College, Mangalore (India); Department of studies in Physics, University of Mysore, Mysore (India); Department of Physics, Bangalore University, Bengaluru (India)

    2012-06-05

    The radiation response of npn Bipolar junction transistor (BJT) has been examined for 100 MeV O{sup 7+} ion. Key electrical properties like Gummel characteristics, dc current gain and capacitance-voltage of 100MeV O{sup 7+} ion irradiated transistor were studied before and after irradiation. The device was decapped and the electrical characterizations were performed at room temperature. Base current is observed to be more sensitive than collector current and gain appears to be degraded with ion fluence, also considerable degradation in C-V characteristics is observed and doping concentration is found to be increased along with the increase in ion fluence.

  18. Spin-torque transistor

    NARCIS (Netherlands)

    Bauer, G.E.W.; Brataas, A.; Tserkovnyak, Y.; Van Wees, B.J.

    2003-01-01

    A magnetoelectronic thin-film transistor is proposed that can display negative differential resistance and gain. The working principle is the modulation of the soure–drain current in a spin valve by the magnetization of a third electrode, which is rotated by the spin-torque created by a control spin

  19. Organic semiconductors for organic field-effect transistors

    Directory of Open Access Journals (Sweden)

    Yoshiro Yamashita

    2009-01-01

    Full Text Available The advantages of organic field-effect transistors (OFETs, such as low cost, flexibility and large-area fabrication, have recently attracted much attention due to their electronic applications. Practical transistors require high mobility, large on/off ratio, low threshold voltage and high stability. Development of new organic semiconductors is key to achieving these parameters. Recently, organic semiconductors have been synthesized showing comparable mobilities to amorphous-silicon-based FETs. These materials make OFETs more attractive and their applications have been attempted. New organic semiconductors resulting in high-performance FET devices are described here and the relationship between transistor characteristics and chemical structure is discussed.

  20. Contribution to the study of the behaviour of silicon planar transistors exposed to the 60Co γ rays

    International Nuclear Information System (INIS)

    Le Ber, J.

    1967-05-01

    This report gives an account of studies carried out on bipolar silicon planar transistors irradiated by 60 Co γ rays. The author describes the interactions on the matter of the different types of particles and he gives a brief bibliographical recall of foreign studies. The technological structure of the planar transistors is then described in order to help the understanding of the phenomena, general comments are made about the choice of measured parameters and on the statistical interpretation of results. An automatic instrument for the measurement of the gain is described and the reproducibility of the results is stated The complexity of the problem and the difficulty to predict the behaviour of the semiconductors components are clearly shown. It is stated that the observed dispersions depend on: - the electrical bias during irradiation - the injection level in the emitter-base junction during the measurement - the manufacturer for a given type - the instantaneous dose rate - the geometry used The problem is then examined from the reliability point of view and methods are given to evaluate the reliability for a given dose - 'Worst case' method - moment method - Monte Carlo method. (author) [fr

  1. Genetics of bipolar disorder

    OpenAIRE

    Kerner, Berit

    2014-01-01

    Berit Kerner Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA Abstract: Bipolar disorder is a common, complex genetic disorder, but the mode of transmission remains to be discovered. Many researchers assume that common genomic variants carry some risk for manifesting the disease. The research community has celebrated the first genome-wide significant associations between common single nucleotide polymorphisms (SNPs) and bipolar ...

  2. [Antidepressants in bipolar disorder].

    Science.gov (United States)

    Courtet, P; Samalin, L; Olié, E

    2011-12-01

    Whereas mania defines the bipolar disorder, depression is the major challenge of treatment. In general, depressions are more frequent, longer, with a major prognostic impact in terms of disability and suicide. How should we treat a patient with bipolar depression? Antidepressants are the treatment of choice for depression, but not in the bipolar disorder. In this context, we have traditionally accepted that antidepressants are effective but they were inducing a significant risk of destabilization of the bipolar disorder, because of the transitions to mania and rapid cycling. Current data reconsider both the two aspects of this risk-benefit ratio. The effectiveness of antidepressants finally seems very limited, especially after the more recent studies with a robust methodology. Manic switches and rapid cycling may not be increased, particularly with new antidepressants and mood stabilizer combinations. The current literature reminds us that these course's modalities are inherent to the disease, with numerous risk factors, and among them, exposure to antidepressants. Who are the bipolar patients who only get the benefits of antidepressant treatment? Research will tell. They are in any case limited. How to navigate in our treatment strategies ? By choosing first drugs that demonstrated efficacy in bipolar depression. When the situation is more complex, "primum non nocere" should lead to support the prescription of the antidepressant in association with mood stabilizer. Copyright © 2011 L’Encéphale. Published by Elsevier Masson SAS.. All rights reserved.

  3. Scalability and reliability issues of Ti/HfOx-based 1T1R bipolar RRAM: Occurrence, mitigation, and solution

    Science.gov (United States)

    Rahaman, Sk. Ziaur; Lee, Heng-Yuan; Chen, Yu-Sheng; Lin, Yu-De; Chen, Pang-Shiu; Chen, Wei-Su; Wang, Pei-Hua

    2017-05-01

    Scalability and reliability issues are the most dominant obstacle for the development of resistive switching memory (RRAM) technology. Owing to the excellent memory performance and process compatibility with current CMOS technology of Ti/HfOx-based filamentary type bipolar RRAM, its scalability and reliability issues have been investigated in this document. Towards this goal, we demonstrate that there exists a clear correlation between the transistor and memory cell, which ultimately limits the scaling in terms of operation current and size of the transistor as well and performance of the Ti/HfOx-based 1T1R bipolar RRAM. Due to the resemblance of switching behaviour between complementary resistive switching, i.e., CRS in a single memory stack, and bipolar resistive switching, the Ti/HfOx-based bipolar RRAM suffers from resistance pinning (RP) issues, whereas the minimum resistance during the 1st RESET operation always impeded below 20 kΩ; this occurs through the interaction between the transistor and memory cell during the FORMING process. However, a sufficiently lower FORMING voltage can mitigate the RP issue occurring in Ti/HfOx-based bipolar RRAM and an alternative Ta buffer layer over HfOx dielectrics is proposed to prevent the activation of self-CRS in the memory cell during the FORMING process.

  4. Junctionless nanowire TFET with built-in N-P-N bipolar action: Physics and operational principle

    Science.gov (United States)

    Rahimian, Morteza; Fathipour, Morteza

    2016-12-01

    In this paper, we present a novel junctionless nanowire tunneling FET (JN-TFET) in which the source region is divided into an n+ as well as a p+ type region. We will show that this structure can provide a built-in n-p-n bipolar junction transistor (BJT) action in the on state of the device. In this regime, tunneling of electrons from the source valence band into the channel conduction band enhances the hole concentration in the p+ source region. Also, the potential in this region is increased, which drives a built-in BJT transistor by forward biasing the base-emitter junction. Thus, the BJT current adds up to the normal tunneling current in the JN-TFET. Owing to the sharp switching of the JN-TFET and the high BJT current gain, the overall performance of the device, herein called "BJN-TFET," is improved. On-state currents as high as 2.17 × 10-6 A/μm and subthreshold swings as low as ˜50 mV/dec at VDS = 1 V are achieved.

  5. TRANSISTOR HIGH VOLTAGE POWER SUPPLY

    Science.gov (United States)

    Driver, G.E.

    1958-07-15

    High voltage, direct current power supplies are described for use with battery powered nuclear detection equipment. The particular advantages of the power supply described, are increased efficiency and reduced size and welght brought about by the use of transistors in the circuit. An important feature resides tn the employment of a pair of transistors in an alternatefiring oscillator circuit having a coupling transformer and other circuit components which are used for interconnecting the various electrodes of the transistors.

  6. Organic electrochemical transistors

    KAUST Repository

    Rivnay, Jonathan

    2018-01-16

    Organic electrochemical transistors (OECTs) make effective use of ion injection from an electrolyte to modulate the bulk conductivity of an organic semiconductor channel. The coupling between ionic and electronic charges within the entire volume of the channel endows OECTs with high transconductance compared with that of field-effect transistors, but also limits their response time. The synthetic tunability, facile deposition and biocompatibility of organic materials make OECTs particularly suitable for applications in biological interfacing, printed logic circuitry and neuromorphic devices. In this Review, we discuss the physics and the mechanism of operation of OECTs, focusing on their identifying characteristics. We highlight organic materials that are currently being used in OECTs and survey the history of OECT technology. In addition, form factors, fabrication technologies and applications such as bioelectronics, circuits and memory devices are examined. Finally, we take a critical look at the future of OECT research and development.

  7. Mesoscopic photon heat transistor

    DEFF Research Database (Denmark)

    Ojanen, T.; Jauho, Antti-Pekka

    2008-01-01

    We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit-leading to the device concept of a mesoscopic photon heat transistor (MPHT). Our theoretical analysis is based on a novel Meir-Wingreen-Landauer-typ......We show that the heat transport between two bodies, mediated by electromagnetic fluctuations, can be controlled with an intermediate quantum circuit-leading to the device concept of a mesoscopic photon heat transistor (MPHT). Our theoretical analysis is based on a novel Meir......-Wingreen-Landauer-type of conductance formula, which gives the photonic heat current through an arbitrary circuit element coupled to two dissipative reservoirs at finite temperatures. As an illustration we present an exact solution for the case when the intermediate circuit can be described as an electromagnetic resonator. We discuss...

  8. Junctionless Cooper pair transistor

    Energy Technology Data Exchange (ETDEWEB)

    Arutyunov, K. Yu., E-mail: konstantin.yu.arutyunov@jyu.fi [National Research University Higher School of Economics , Moscow Institute of Electronics and Mathematics, 101000 Moscow (Russian Federation); P.L. Kapitza Institute for Physical Problems RAS , Moscow 119334 (Russian Federation); Lehtinen, J.S. [VTT Technical Research Centre of Finland Ltd., Centre for Metrology MIKES, P.O. Box 1000, FI-02044 VTT (Finland)

    2017-02-15

    Highlights: • Junctionless Cooper pair box. • Quantum phase slips. • Coulomb blockade and gate modulation of the Coulomb gap. - Abstract: Quantum phase slip (QPS) is the topological singularity of the complex order parameter of a quasi-one-dimensional superconductor: momentary zeroing of the modulus and simultaneous 'slip' of the phase by ±2π. The QPS event(s) are the dynamic equivalent of tunneling through a conventional Josephson junction containing static in space and time weak link(s). Here we demonstrate the operation of a superconducting single electron transistor (Cooper pair transistor) without any tunnel junctions. Instead a pair of thin superconducting titanium wires in QPS regime was used. The current–voltage characteristics demonstrate the clear Coulomb blockade with magnitude of the Coulomb gap modulated by the gate potential. The Coulomb blockade disappears above the critical temperature, and at low temperatures can be suppressed by strong magnetic field.

  9. Metatronic transistor amplifier

    Science.gov (United States)

    Chettiar, Uday K.; Engheta, Nader

    2015-10-01

    Utilizing the notion of metamaterials, in recent years the concept of a circuit and lumped circuit elements have been extended to the optical domains, providing the paradigm of optical metatronics, i.e., metamaterial-inspired optical nanocircuitry, as a powerful tool for design and study of more complex systems at the nanoscale. In this paper we present a design for a new metatronic element, namely, a metatronic transistor that functions as an amplifier. As shown by our analytical and numerical paper here, this metatronic transistor provides gain as well as isolation between the input and output ports of such two-port device. The cascadability and fan-out aspects of this element are also explored.

  10. Organic electrochemical transistors

    Science.gov (United States)

    Rivnay, Jonathan; Inal, Sahika; Salleo, Alberto; Owens, Róisín M.; Berggren, Magnus; Malliaras, George G.

    2018-02-01

    Organic electrochemical transistors (OECTs) make effective use of ion injection from an electrolyte to modulate the bulk conductivity of an organic semiconductor channel. The coupling between ionic and electronic charges within the entire volume of the channel endows OECTs with high transconductance compared with that of field-effect transistors, but also limits their response time. The synthetic tunability, facile deposition and biocompatibility of organic materials make OECTs particularly suitable for applications in biological interfacing, printed logic circuitry and neuromorphic devices. In this Review, we discuss the physics and the mechanism of operation of OECTs, focusing on their identifying characteristics. We highlight organic materials that are currently being used in OECTs and survey the history of OECT technology. In addition, form factors, fabrication technologies and applications such as bioelectronics, circuits and memory devices are examined. Finally, we take a critical look at the future of OECT research and development.

  11. Common and distinct structural features of schizophrenia and bipolar disorder: The European Network on Psychosis, Affective disorders and Cognitive Trajectory (ENPACT study.

    Directory of Open Access Journals (Sweden)

    Eleonora Maggioni

    Full Text Available Although schizophrenia (SCZ and bipolar disorder (BD share elements of pathology, their neural underpinnings are still under investigation. Here, structural Magnetic Resonance Imaging (MRI data collected from a large sample of BD and SCZ patients and healthy controls (HC were analyzed in terms of gray matter volume (GMV using both voxel based morphometry (VBM and a region of interest (ROI approach.The analysis was conducted on two datasets, Dataset1 (802 subjects: 243 SCZ, 176 BD, 383 HC and Dataset2, a homogeneous subset of Dataset1 (301 subjects: 107 HC, 85 BD and 109 SCZ. General Linear Model analyses were performed 1 at the voxel-level in the whole brain (VBM study, 2 at the regional level in the anatomical regions emerged from the VBM study (ROI study. The GMV comparison across groups was integrated with the analysis of GMV correlates of different clinical dimensions.The VBM results of Dataset1 showed 1 in BD compared to HC, GMV deficits in right cingulate, superior temporal and calcarine cortices, 2 in SCZ compared to HC, GMV deficits in widespread cortical and subcortical areas, 3 in SCZ compared to BD, GMV deficits in insula and thalamus (p<0.05, cluster family wise error corrected. The regions showing GMV deficits in the BD group were mostly included in the SCZ ones. The ROI analyses confirmed the VBM results at the regional level in most of the clusters from the SCZ vs. HC comparison (p<0.05, Bonferroni corrected. The VBM and ROI analyses of Dataset2 provided further evidence for the enhanced GMV deficits characterizing SCZ. Based on the clinical-neuroanatomical analyses, we cannot exclude possible confounding effects due to 1 age of onset and medication in BD patients, 2 symptoms severity in SCZ patients.Our study reported both shared and specific neuroanatomical characteristics between the two disorders, suggesting more severe and generalized GMV deficits in SCZ, with a specific role for insula and thalamus.

  12. Polarization induced doped transistor

    Science.gov (United States)

    Xing, Huili; Jena, Debdeep; Nomoto, Kazuki; Song, Bo; Zhu, Mingda; Hu, Zongyang

    2016-06-07

    A nitride-based field effect transistor (FET) comprises a compositionally graded and polarization induced doped p-layer underlying at least one gate contact and a compositionally graded and doped n-channel underlying a source contact. The n-channel is converted from the p-layer to the n-channel by ion implantation, a buffer underlies the doped p-layer and the n-channel, and a drain underlies the buffer.

  13. Depression and Bipolar Support Alliance

    Science.gov (United States)

    Depression and Bipolar Support Alliance Crisis Hotline Information Coping with a Crisis Suicide Prevention Information Psychiatric Hospitalization ... sign-up Education info, training, events Mood Disorders Depression Bipolar Disorder Anxiety Screening Center Co-occurring Illnesses/ ...

  14. Bipolar Affective Disorder and Migraine

    Directory of Open Access Journals (Sweden)

    Birk Engmann

    2012-01-01

    Full Text Available This paper consists of a case history and an overview of the relationship, aetiology, and treatment of comorbid bipolar disorder migraine patients. A MEDLINE literature search was used. Terms for the search were bipolar disorder bipolar depression, mania, migraine, mood stabilizer. Bipolar disorder and migraine cooccur at a relatively high rate. Bipolar II patients seem to have a higher risk of comorbid migraine than bipolar I patients have. The literature on the common roots of migraine and bipolar disorder, including both genetic and neuropathological approaches, is broadly discussed. Moreover, bipolar disorder and migraine are often combined with a variety of other affective disorders, and, furthermore, behavioural factors also play a role in the origin and course of the diseases. Approach to treatment options is also difficult. Several papers point out possible remedies, for example, valproate, topiramate, which acts on both diseases, but no first-choice treatments have been agreed upon yet.

  15. Interface Engineering for Precise Threshold Voltage Control in Multilayer-Channel Thin Film Transistors

    KAUST Repository

    Park, Jihoon

    2016-11-29

    Multilayer channel structure is used to effectively manipulate the threshold voltage of zinc oxide transistors without degrading its field-effect mobility. Transistors operating in enhancement mode with good mobility are fabricated by optimizing the structure of the multilayer channel. The optimization is attributed to the formation of additional channel and suppression of the diffusion of absorbed water molecules and oxygen vacancies.

  16. Reaching saturation in patterned source vertical organic field effect transistors

    Science.gov (United States)

    Greenman, Michael; Sheleg, Gil; Keum, Chang-min; Zucker, Jonathan; Lussem, Bjorn; Tessler, Nir

    2017-05-01

    Like most of the vertical transistors, the Patterned Source Vertical Organic Field Effect Transistor (PS-VOFET) does not exhibit saturation in the output characteristics. The importance of achieving a good saturation is demonstrated in a vertical organic light emitting transistor; however, this is critical for any application requiring the transistor to act as a current source. Thereafter, a 2D simulation tool was used to explain the physical mechanisms that prevent saturation as well as to suggest ways to overcome them. We found that by isolating the source facet from the drain-source electric field, the PS-VOFET architecture exhibits saturation. The process used for fabricating such saturation-enhancing structure is then described. The new device demonstrated close to an ideal saturation with only 1% change in the drain-source current over a 10 V change in the drain-source voltage.

  17. A simple and controlled single electron transistor based on doping modulation in silicon nanowires

    OpenAIRE

    Hofheinz, M.; Jehl, X.; Sanquer, M.; Molas, G.; Vinet, M.; Deleonibus, S.

    2006-01-01

    A simple and highly reproducible single electron transistor (SET) has been fabricated using gated silicon nanowires. The structure is a metal-oxide-semiconductor field-effect transistor made on silicon-on-insulator thin films. The channel of the transistor is the Coulomb island at low temperature. Two silicon nitride spacers deposited on each side of the gate create a modulation of doping along the nanowire that creates tunnel barriers. Such barriers are fixed and controlled, like in metallic...

  18. A study of genetic and environmental contributions to structural brain changes over time in twins concordant and discordant for bipolar disorder

    NARCIS (Netherlands)

    Bootsman, F.; Brouwer, R. M.; Schnack, H. G.; Kemner, S. M.; Hillegers, M. H. J.; Sarkisyan, G.; van der Schot, A. C.; Vonk, R.; Pol, H. E. Hulshoff; Nolen, W. A.; Kahn, R. S.; van Haren, N. E. M.

    This is the first longitudinal twin study examining genetic and environmental contributions to the association between liability to bipolar disorder (BD) and changes over time in global brain volumes, and global and regional measures of cortical surface area, cortical thickness and cortical volume.

  19. BUSFET -- A radiation-hardened SOI transistor

    International Nuclear Information System (INIS)

    Schwank, J.R.; Shaneyfelt, M.R.; Draper, B.L.; Dodd, P.E.

    1999-01-01

    The total-dose hardness of SOI technology is limited by radiation-induced charge trapping in gate, field, and SOI buried oxides. Charge trapping in the buried oxide can lead to back-channel leakage and makes hardening SOI transistors more challenging than hardening bulk-silicon transistors. Two avenues for hardening the back-channel are (1) to use specially prepared SOI buried oxides that reduce the net amount of trapped positive charge or (2) to design transistors that are less sensitive to the effects of trapped charge in the buried oxide. In this work, the authors propose a partially-depleted SOI transistor structure for mitigating the effects of trapped charge in the buried oxide on radiation hardness. They call this structure the BUSFET--Body Under Source FET. The BUSFET utilizes a shallow source and a deep drain. As a result, the silicon depletion region at the back channel caused by radiation-induced charge trapping in the buried oxide does not form a conducting path between source and drain. Thus, the BUSFET structure design can significantly reduce radiation-induced back-channel leakage without using specially prepared buried oxides. Total dose hardness is achieved without degrading the intrinsic SEU or dose rate hardness of SOI technology. The effectiveness of the BUSFET structure for reducing total-dose back-channel leakage depends on several variables, including the top silicon film thickness and doping concentration, and the depth of the source. 3-D simulations show that for a body doping concentration of 10 18 cm -3 , a drain bias of 3 V, and a source depth of 90 nm, a silicon film thickness of 180 nm is sufficient to almost completely eliminate radiation-induced back-channel leakage. However, for a doping concentration of 3 x 10 17 cm -3 , a thicker silicon film (300 nm) must be used

  20. A Built-In Self-Test Structure (BIST) for Resistive RAMs characterization: Application to bipolar OxRRAM

    Science.gov (United States)

    Aziza, H.; Bocquet, M.; Moreau, M.; Portal, J.-M.

    2015-01-01

    Resistive Random Access Memory (RRAM) is a form of nonvolatile storage that operates by changing the resistance of a specially formulated solid dielectric material [1]. Among RRAMs, oxide-based Resistive RAMs (so-called OxRRAMs) are promising candidates due their compatibility with CMOS processes and high ON/OFF resistance ratio. Common problems with OxRRAM are related to high variability in operating conditions and low yield. OxRRAM variability mainly impact ON/OFF resistance ratio. This ratio is a key parameter to determine the overall performance of an OxRRAM memory. In this context, the presented built-in structure allows collecting statistical data related to the OxRRAM memory array (ON/OFF resistance distributions) for reliability assessment of the technology.

  1. Investigation of structural, optical, and electrical characteristics of an AlGaN/GaN high electron mobility transistor structure across a 200 mm Si(1 1 1) substrate

    International Nuclear Information System (INIS)

    Perozek, J; Lee, H-P; Bayram, C; Krishnan, B; Paranjpe, A; Reuter, K B; Sadana, D K

    2017-01-01

    An AlGaN/GaN high electron mobility transistor (HEMT) structure is grown on a 200 mm Si(1 1 1) substrate. The AlGaN/AlN/GaN heterostructure atop, which forms the 2D electron gas, is studied via transmission electron microscopy (TEM), scanning tunneling microscopy, and TEM chemical analysis. To quantify the uniformity of structural, optical, and electrical properties of these AlGaN/GaN HEMT structures, scanning electron microscopy, optical microscopy, atomic-force microscopy, x-ray diffraction ( ω /2 θ scan and reciprocal space mapping) and Hall effect measurements are employed across the center, middle, and edge of the 200 mm wafer. Small thickness (<3%) and Al-content (<3%) variations in (Al)GaN layers across the wafer are recorded whereas a considerable change (28%) in the electron mobility is observed across the wafer that correlates with variations in surface roughness, defectivity, and layer stress. We attribute the higher mobility in the middle of the wafer to lower interface scattering, thanks to lower surface roughness and less edge-type dislocation density. Additionally, argon (Ar) ion implantation is used as a means for planar electrical isolation, and a seven orders of magnitude decrease in leakage current is achieved when an optimum Ar dose of 10 13 cm −2 is used. The feasibility of scaling AlGaN/GaN HEMTs on a 200 mm Si(1 1 1) platform is discussed. (paper)

  2. Depressive and bipolar disorders

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Hansen, Hanne Vibe; Demyttenaere, Koen

    2005-01-01

    BACKGROUND: There is increasing evidence that attitudes and beliefs are important in predicting adherence to treatment and medication in depressive and bipolar disorders. However, these attitudes have received little study in patients whose disorders were sufficiently severe to require...... hospitalization. METHOD: The Antidepressant Compliance Questionnaire (ADCQ) was mailed to a large population of patients with depressive or bipolar disorder, representative of patients treated in hospital settings in Denmark. RESULTS: Of the 1005 recipients, 49.9% responded to the letter. A large proportion....... Moreover, their partners agreed on these negative views. Women had a more negative view of the doctor-patient relationship than men, and patients with a depressive disorder had a more negative view of antidepressants than patients with bipolar disorder. The number of psychiatric hospitalizations...

  3. High Gamma Ray Tolerance for 4H-SiC Bipolar Circuits

    Science.gov (United States)

    Suvanam, Sethu Saveda; Kuroki, Shin-Ichiro; Lanni, Luigia; Hadayati, Raheleh; Ohshima, Takeshi; Makino, Takahiro; Hallén, Anders; Zetterling, Carl-Mikael

    2017-02-01

    A high gamma radiation hardness of 4H-SiC circuits is performed. The OR NOR circuits are based on emitter coupled logic (ECL), using integrated bipolar NPN transistors. Gain degradation in individual bipolar junction transistors (BJT) is minimal up to a dose of 38 Mrad (SiO2), but for the dose of 332 Mrad (SiO2) a degradation of 52% is observed. The SiC BJTs show higher radiation hardness than existing Si-technology and high stability under temperature stress. It is proposed that the oxide charge-dominated recombination is the key base current recombination mechanism contributing to gain degradation. An improvement in the gain is seen after annealing at 400 °C for 1800 s due to the possible annealing of some of the oxide defects contributing to the oxide charge.

  4. Effect of circuital currents on the speed and efficiency of picosecond-range switching in a GaAs avalanche transistor

    Science.gov (United States)

    Vainshtein, Sergey; Yuferev, Valentin; Kostamovaara, Juha

    2005-04-01

    Ultrafast (picosecond range) switching of a GaAs-based BJT (bipolar junction transistor) in the avalanche mode has recently been demonstrated experimentally. It was found to be caused by the formation and spread of ultra-high amplitude multiple Gunn domains, which cause extremely powerful avalanching in the volume of the switching filaments. Unavoidable parasitic impedance of an external circuit limits the rate of avalanche carrier generation in the channels, however, which slows down the switching and increases the residual voltage across the switch. We present here the results of simulations which show that the switching transient can be significantly accelerated and the residual voltage reduced due to the supporting of a higher current density in the channels by the charge stored in the barrier capacitance of the non-switched part of the structure. The corresponding circuital currents are confined in low-inductance loops inside the structure and are not critically affected by the parameters of the external circuit. This provides very fast and effective reduction in the collector voltage, provided the parameters of the semiconductor layers and the geometry of the device are selected properly. Particularly significant in this process is the effect of circuital current saturation in the lightly doped collector region of the non-switched part of the transistor. The results of the simulations with the barrier capacitance included in the model are in excellent agreement with the experimental data.

  5. Atypical transistor-based chaotic oscillators: Design, realization, and diversity

    Science.gov (United States)

    Minati, Ludovico; Frasca, Mattia; OświÈ©cimka, Paweł; Faes, Luca; DroŻdŻ, Stanisław

    2017-07-01

    In this paper, we show that novel autonomous chaotic oscillators based on one or two bipolar junction transistors and a limited number of passive components can be obtained via random search with suitable heuristics. Chaos is a pervasive occurrence in these circuits, particularly after manual adjustment of a variable resistor placed in series with the supply voltage source. Following this approach, 49 unique circuits generating chaotic signals when physically realized were designed, representing the largest collection of circuits of this kind to date. These circuits are atypical as they do not trivially map onto known topologies or variations thereof. They feature diverse spectra and predominantly anti-persistent monofractal dynamics. Notably, we recurrently found a circuit comprising one resistor, one transistor, two inductors, and one capacitor, which generates a range of attractors depending on the parameter values. We also found a circuit yielding an irregular quantized spike-train resembling some aspects of neural discharge and another one generating a double-scroll attractor, which represent the smallest known transistor-based embodiments of these behaviors. Through three representative examples, we additionally show that diffusive coupling of heterogeneous oscillators of this kind may give rise to complex entrainment, such as lag synchronization with directed information transfer and generalized synchronization. The replicability and reproducibility of the experimental findings are good.

  6. Tailoring the Dielectric Layer Structure for Enhanced Performance of Organic Field-Effect Transistors: The Use of a Sandwiched Polar Dielectric Layer.

    Science.gov (United States)

    Han, Shijiao; Yang, Xin; Zhuang, Xinming; Yu, Junsheng; Li, Lu

    2016-07-07

    To investigate the origins of hydroxyl groups in a polymeric dielectric and its applications in organic field-effect transistors (OFETs), a polar polymer layer was inserted between two polymethyl methacrylate (PMMA) dielectric layers, and its effect on the performance as an organic field-effect transistor (OFET) was studied. The OFETs with a sandwiched dielectric layer of poly(vinyl alcohol) (PVA) or poly(4-vinylphenol) (PVP) containing hydroxyl groups had shown enhanced characteristics compared to those with only PMMA layers. The field-effect mobility had been raised more than 10 times in n -type devices (three times in the p -type one), and the threshold voltage had been lowered almost eight times in p -type devices (two times in the n -type). The on-off ratio of two kinds of devices had been enhanced by almost two orders of magnitude. This was attributed to the orientation of hydroxyl groups from disordered to perpendicular to the substrate under gate-applied voltage bias, and additional charges would be induced by this polarization at the interface between the semiconductor and dielectrics, contributing to the accumulation of charge transfer.

  7. Tailoring the Dielectric Layer Structure for Enhanced Performance of Organic Field-Effect Transistors: The Use of a Sandwiched Polar Dielectric Layer

    Directory of Open Access Journals (Sweden)

    Shijiao Han

    2016-07-01

    Full Text Available To investigate the origins of hydroxyl groups in a polymeric dielectric and its applications in organic field-effect transistors (OFETs, a polar polymer layer was inserted between two polymethyl methacrylate (PMMA dielectric layers, and its effect on the performance as an organic field-effect transistor (OFET was studied. The OFETs with a sandwiched dielectric layer of poly(vinyl alcohol (PVA or poly(4-vinylphenol (PVP containing hydroxyl groups had shown enhanced characteristics compared to those with only PMMA layers. The field-effect mobility had been raised more than 10 times in n-type devices (three times in the p-type one, and the threshold voltage had been lowered almost eight times in p-type devices (two times in the n-type. The on-off ratio of two kinds of devices had been enhanced by almost two orders of magnitude. This was attributed to the orientation of hydroxyl groups from disordered to perpendicular to the substrate under gate-applied voltage bias, and additional charges would be induced by this polarization at the interface between the semiconductor and dielectrics, contributing to the accumulation of charge transfer.

  8. Spin Hall effect transistor

    Czech Academy of Sciences Publication Activity Database

    Wunderlich, Joerg; Park, B.G.; Irvine, A.C.; Zarbo, Liviu; Rozkotová, E.; Němec, P.; Novák, Vít; Sinova, Jairo; Jungwirth, Tomáš

    2010-01-01

    Roč. 330, č. 6012 (2010), s. 1801-1804 ISSN 0036-8075 R&D Projects: GA AV ČR KAN400100652; GA MŠk LC510 EU Projects: European Commission(XE) 215368 - SemiSpinNet Grant - others:AV ČR(CZ) AP0801 Program:Akademická prémie - Praemium Academiae Institutional research plan: CEZ:AV0Z10100521 Keywords : spin Hall effect * spintronics * spin transistor Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 31.364, year: 2010

  9. Quantum Transport in Ultra-scaled Junctionless Transistors

    Science.gov (United States)

    Kim, Sunggeun; Luisier, Mathieu; Klimeck, Gerhard

    2012-02-01

    As the dimensions of metal-oxide-semiconductor field-effect transistors have been scaled down to a few nano-meters, short channel effects have started to significantly degrade their performance. The junctionless transistor is an alternative device structure which is expected to reduce short channel effects. However, an extreme device scaling raises another issue, namely, source-to-drain tunneling. Junctionless transistors contain several doping atoms in the channel which can enhance tunneling processes and cause electrons to scatter with them. Through self-consistent quantum transport simulations based on the tight-binding model with elelctron-phonon scattering included, it is found that junctionless nanowire transistors with a gate length of 5 nm do not outperform conventional inversion-mode transistors with the same dimension in terms of their on-state characteristics, mainly due to impurity scattering in the channel. The advantage of the junctionless transistor in the the subthreshold region vanishes due to large tunneling currents through doping impurities.

  10. Direct coupled amplifiers using field effect transistors

    International Nuclear Information System (INIS)

    Fowler, E.P.

    1964-03-01

    The concept of the uni-polar field effect transistor (P.E.T.) was known before the invention of the bi-polar transistor but it is only recently that they have been made commercially. Being produced as yet only in small quantities, their price imposes a restriction on use to circuits where their peculiar properties can be exploited to the full. One such application is described here where the combination of low voltage drift and relatively low input leakage current are necessarily used together. One of the instruments used to control nuclear reactors has a logarithmic response to the mean output current from a polarised ionisation chamber. The logarithmic signal is then differentiated electrically, the result being displayed on a meter calibrated to show the reactor divergence or doubling time. If displayed in doubling time the scale is calibrated reciprocally. Because of the wide range obtained in the logarithmic section and the limited supply voltage, an output of 1 volt per decade change in ionisation current is used. Differentiating this gives a current of 1.5 x 10 -8 A for p.s.D. (20 sec. doubling time) in the differentiating amplifier. To overcome some of the problems of noise due to statistical variations in input current, the circuit design necessitates a resistive path to ground at the amplifier input of 20 M.ohms. A schematic diagram is shown. 1. It is evident that a zero drift of 1% can be caused by a leakage current of 1.5 x 10 -10 A or an offset voltage of 3 mV at the amplifier input. Although the presently used electrometer valve is satisfactory from the point of view of grid current, there have been sudden changes in grid to grid voltage (the valve is a double triode) of up to 10 m.V. It has been found that a pair of F.E.T's. can be used to replace the electrometer valve so long as care is taken in correct balance of the two devices. An investigation has been made into the characteristics of some fourteen devices to see whether those with very

  11. Novel multiple criteria decision making methods based on bipolar neu trosophic sets and bipolar neutrosophic graphs

    OpenAIRE

    Muhammad Akram; Musavarah Sarwar

    2017-01-01

    In this research article, we present certain notions of bipolar neutrosophic graphs. We study the dominating and independent sets of bipolar neutrosophic graphs. We describe novel multiple criteria decision making methods based on bipolar neutrosophic sets and bipolar neutrosophic graphs.

  12. Discrete bipolar universal integrals

    Czech Academy of Sciences Publication Activity Database

    Greco, S.; Mesiar, Radko; Rindone, F.

    2014-01-01

    Roč. 252, č. 1 (2014), s. 55-65 ISSN 0165-0114 R&D Projects: GA ČR GAP402/11/0378 Institutional support: RVO:67985556 Keywords : bipolar integral * universal integral * Choquet integral Subject RIV: BA - General Mathematics Impact factor: 1.986, year: 2014 http://library.utia.cas.cz/separaty/2014/E/mesiar-0432224.pdf

  13. [Spouses and bipolar disorder].

    Science.gov (United States)

    Ellouze, F; Ayedi, S; Cherif, W; Ben Abla, T; M'rad, M F

    2011-02-01

    To assess the quality of life of a population of spouses of bipolar patients compared with a control population. We conducted a cross-sectional study which included two groups: a group of 30 spouses of patients followed for bipolar I disorder according to DSM IV criteria and a second group of 30 subjects from the general population. Both groups were matched by age, sex, marital status and socioeconomic level. This device was designed to limit the differences between the two groups solely those of the bipolar illness. Evaluating the quality of life was achieved using the quality of life scale: SF-36. This is a scale that has already been translated and validated in dialect Arabic. Regarding sociodemographic variables, the two study groups differed only for: recreation, friendly relations and the couple relationship that included more and better skills among the control group. In the categorical approach, the quality of life was impaired in 60% of spouses and 40% of controls with a statistically significant difference. The following standardized dimensions: mental health (D4), limitation due to mental health (D5), life and relationship with others (D6) and perceived health (D8) and mental component (CM) were significantly altered in patients' spouses compared to controls. We found significant differences between the two groups for: overall average score (51.1 vs. 68.2), mental health (D4), limitation due to mental health (D5), life and relationship with others (D6), perceived health (D8) and perceived health (D8) standards. The impairment of quality of life of bipolar patients' spouses is related to the extra responsibility, stress, financial problems and health problems, stigma, and loss of security of the person loved. Considering the consequences that the appearance of bipolar disorder on the patient's spouse may have, certain measures must be proposed to improve their quality of life. Copyright © 2010 L'Encéphale, Paris. Published by Elsevier Masson SAS. All

  14. ON BIPOLAR SINGLE VALUED NEUTROSOPHIC GRAPHS

    OpenAIRE

    Broumi, Said; Talea, Mohamed; Bakali, Assia; Smarandache, Florentin

    2016-01-01

    In this article, we combine the concept of bipolar neutrosophic set and graph theory. We introduce the notions of bipolar single valued neutrosophic graphs, strong bipolar single valued neutrosophic graphs, complete bipolar single valued neutrosophic graphs, regular bipolar single valued neutrosophic graphs and investigate some of their related properties.

  15. Solution-processed ambipolar organic field-effect transistors and inverters

    NARCIS (Netherlands)

    Meijer, E.J.; Leeuw, D.M. de; Setayesh, S.; Veenendaal, E. van; Huisman, B.H.; Blom, P.W.M.; Hummelen, J.C.; Scherf, U.; Klapwijk, T.M.

    2003-01-01

    There is ample evidence that organic field-effect transistors have reached a stage where they can be industrialized, analogous to standard metal oxide semiconductor (MOS) transistors. Monocrystalline silicon technology is largely based on complementary MOS (CMOS) structures that use both n-type and

  16. Transistor effects and in situ STM of redox molecules at room temperature

    DEFF Research Database (Denmark)

    Albrecht, Tim; Guckian, A; Vos, JG

    2005-01-01

    Inorganic transition metal complexes were identified as potential candidates for transistor-like behavior in an electrochemical scanning tunnelling microscope (STM) configuration at room temperature. The theoretical background has been established based on condensed matter charge transfer theory...... resolution reveal detailed information on their surface structure and scanning tunnelling spectroscopy experiments have shown clear evidence of transistor-like behavior...

  17. Transistor Effects and in situ STM of Redox Molecules at Room Temperature

    DEFF Research Database (Denmark)

    Albrecht, T.; Guckian, A.; Ulstrup, Jens

    2004-01-01

    Inorganic transition metal complexes were identified as potential candidates for transistor-like behaviour in an electrochemical STM configuration at room temperature. The theoretical background has been established based on condensed matter charge transfer theory. It predicts a distinct increase...... into the surface structure. STS experiments are on the way to probe putative transistor-like behaviour....

  18. Electric double layer transistors with ferroelectric BaTiO3 channels

    NARCIS (Netherlands)

    Ito, M.; Matsubara, Y.; Kozuka, Y.; Takahashi, K. S.; Kagawa, F.; Ye, J. T.; Iwasa, Y.; Ueno, K.; Tokura, Y.; Kawasaki, M.

    2014-01-01

    We report the surface conduction of a BaTiO3 thin film using electric double layer transistor (EDLT) structure. A transistor operation was observed at 220 K with an on/off ratio exceeding 10(5), demonstrating that ionic liquid gating is effective to induce carriers at the surface of ferroelectric

  19. Analysis of long-channel nanotube field-effect-transistors (NT FETs)

    Science.gov (United States)

    Toshishige, Yamada; Kwak, Dochan (Technical Monitor)

    2001-01-01

    This viewgraph presentation provides an analysis of long-channel nanotube (NT) field effect transistors (FET) from NASA's Ames Research Center. The structure of such a transistor including the electrode contact, 1D junction, and the planar junction is outlined. Also mentioned are various characteristics of a nanotube tip-equipped scanning tunnel microscope (STM).

  20. Copper atomic-scale transistors

    Directory of Open Access Journals (Sweden)

    Fangqing Xie

    2017-03-01

    Full Text Available We investigated copper as a working material for metallic atomic-scale transistors and confirmed that copper atomic-scale transistors can be fabricated and operated electrochemically in a copper electrolyte (CuSO4 + H2SO4 in bi-distilled water under ambient conditions with three microelectrodes (source, drain and gate. The electrochemical switching-on potential of the atomic-scale transistor is below 350 mV, and the switching-off potential is between 0 and −170 mV. The switching-on current is above 1 μA, which is compatible with semiconductor transistor devices. Both sign and amplitude of the voltage applied across the source and drain electrodes (Ubias influence the switching rate of the transistor and the copper deposition on the electrodes, and correspondingly shift the electrochemical operation potential. The copper atomic-scale transistors can be switched using a function generator without a computer-controlled feedback switching mechanism. The copper atomic-scale transistors, with only one or two atoms at the narrowest constriction, were realized to switch between 0 and 1G0 (G0 = 2e2/h; with e being the electron charge, and h being Planck’s constant or 2G0 by the function generator. The switching rate can reach up to 10 Hz. The copper atomic-scale transistor demonstrates volatile/non-volatile dual functionalities. Such an optimal merging of the logic with memory may open a perspective for processor-in-memory and logic-in-memory architectures, using copper as an alternative working material besides silver for fully metallic atomic-scale transistors.

  1. Early Intervention in Bipolar Disorder.

    Science.gov (United States)

    Vieta, Eduard; Salagre, Estela; Grande, Iria; Carvalho, André F; Fernandes, Brisa S; Berk, Michael; Birmaher, Boris; Tohen, Mauricio; Suppes, Trisha

    2018-01-24

    Bipolar disorder is a recurrent disorder that affects more than 1% of the world population and usually has its onset during youth. Its chronic course is associated with high rates of morbidity and mortality, making bipolar disorder one of the main causes of disability among young and working-age people. The implementation of early intervention strategies may help to change the outcome of the illness and avert potentially irreversible harm to patients with bipolar disorder, as early phases may be more responsive to treatment and may need less aggressive therapies. Early intervention in bipolar disorder is gaining momentum. Current evidence emerging from longitudinal studies indicates that parental early-onset bipolar disorder is the most consistent risk factor for bipolar disorder. Longitudinal studies also indicate that a full-blown manic episode is often preceded by a variety of prodromal symptoms, particularly subsyndromal manic symptoms, therefore supporting the existence of an at-risk state in bipolar disorder that could be targeted through early intervention. There are also identifiable risk factors that influence the course of bipolar disorder, some of them potentially modifiable. Valid biomarkers or diagnosis tools to help clinicians identify individuals at high risk of conversion to bipolar disorder are still lacking, although there are some promising early results. Pending more solid evidence on the best treatment strategy in early phases of bipolar disorder, physicians should carefully weigh the risks and benefits of each intervention. Further studies will provide the evidence needed to finish shaping the concept of early intervention.

  2. A comparative study of n-channel low temperature poly-Si thin-film transistors with a body terminal or a lightly-doped-drain structure

    Science.gov (United States)

    Wu, Yanwen; Wang, Mingxiang; Wang, Huaisheng; Zhang, Dongli

    2018-02-01

    Hot-carrier (HC) induced degradation is a critical reliability issue of n-channel low temperature poly-Si thin-film transistors (TFTs) in TFT-based circuits. In this work, a kind of four-terminal TFT, which has an additional p+-doped lateral body terminal connecting to the floating channel, is systematically compared to conventional n-channel TFT and lightly-doped-drain (LDD) TFT. We demonstrate that the four-terminal TFT can provide similar advantages to that of the LDD TFT such as kink current suppression and DC HC degradation immunity, much superior immunity to the dynamic HC degradation, but without any tradeoffs in device performance and process complexity of the LDD TFT. It has high performance, as well as excellent reliability under both DC and AC conditions.

  3. Vertical Ge/Si Core/Shell Nanowire Junctionless Transistor.

    Science.gov (United States)

    Chen, Lin; Cai, Fuxi; Otuonye, Ugo; Lu, Wei D

    2016-01-13

    Vertical junctionless transistors with a gate-all-around (GAA) structure based on Ge/Si core/shell nanowires epitaxially grown and integrated on a ⟨111⟩ Si substrate were fabricated and analyzed. Because of efficient gate coupling in the nanowire-GAA transistor structure and the high density one-dimensional hole gas formed in the Ge nanowire core, excellent P-type transistor behaviors with Ion of 750 μA/μm were obtained at a moderate gate length of 544 nm with minimal short-channel effects. The experimental data can be quantitatively modeled by a GAA junctionless transistor model with few fitting parameters, suggesting the nanowire transistors can be fabricated reliably without introducing additional factors that can degrade device performance. Devices with different gate lengths were readily obtained by tuning the thickness of an etching mask film. Analysis of the histogram of different devices yielded a single dominate peak in device parameter distribution, indicating excellent uniformity and high confidence of single nanowire operation. Using two vertical nanowire junctionless transistors, a PMOS-logic inverter with near rail-to-rail output voltage was demonstrated, and device matching in the logic can be conveniently obtained by controlling the number of nanowires employed in different devices rather than modifying device geometry. These studies show that junctionless transistors based on vertical Ge/Si core/shell nanowires can be fabricated in a controlled fashion with excellent performance and may be used in future hybrid, high-performance circuits where bottom-up grown nanowire devices with different functionalities can be directly integrated with an existing Si platform.

  4. Recent progress in photoactive organic field-effect transistors

    OpenAIRE

    Wakayama, Yutaka; Hayakawa, Ryoma; Seo, Hoon-Seok

    2014-01-01

    Recent progress in photoactive organic field-effect transistors (OFETs) is reviewed. Photoactive OFETs are divided into light-emitting (LE) and light-receiving (LR) OFETs. In the first part, LE-OFETs are reviewed from the viewpoint of the evolution of device structures. Device performances have improved in the last decade with the evolution of device structures from single-layer unipolar to multi-layer ambipolar transistors. In the second part, various kinds of LR-OFETs are featured. These ar...

  5. Life expectancy in bipolar disorder

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Vradi, Eleni; Andersen, Per Kragh

    2015-01-01

    OBJECTIVE: Life expectancy in patients with bipolar disorder has been reported to be decreased by 11 to 20 years. These calculations are based on data for individuals at the age of 15 years. However, this may be misleading for patients with bipolar disorder in general as most patients have a later...... onset of illness. The aim of the present study was to calculate the remaining life expectancy for patients of different ages with a diagnosis of bipolar disorder. METHODS: Using nationwide registers of all inpatient and outpatient contacts to all psychiatric hospitals in Denmark from 1970 to 2012 we...... remaining life expectancy in bipolar disorder and that of the general population decreased with age, indicating that patients with bipolar disorder start losing life-years during early and mid-adulthood. CONCLUSIONS: Life expectancy in bipolar disorder is decreased substantially, but less so than previously...

  6. Bipolar Disorder and Alcoholism: Are They Related?

    Science.gov (United States)

    ... Is there a connection between bipolar disorder and alcoholism? Answers from Daniel K. Hall-Flavin, M.D. Bipolar disorder and alcoholism often occur together. Although the association between bipolar ...

  7. Identifying early indicators in bipolar disorder: a qualitative study.

    Science.gov (United States)

    Benti, Liliane; Manicavasagar, Vijaya; Proudfoot, Judy; Parker, Gordon

    2014-06-01

    The identification of early markers has become a focus for early intervention in bipolar disorder. Using a retrospective, qualitative methodology, the present study compares the early experiences of participants with bipolar disorder to those with unipolar depression up until their first diagnosed episode. The study focuses on differences in early home and school environments as well as putative differences in personality characteristics between the two groups. Finally we a compare and contrast prodromal symptoms in these two populations. Thirty-nine participants, 20 diagnosed with unipolar depression and 19 diagnosed with bipolar disorder, took part in the study. A semi-structured interview was developed to elicit information about participants' experiences prior to their first episode. Participants with bipolar disorder reported disruptive home environments, driven personality features, greater emotion dysregulation and adverse experiences during the school years, whereas participants with depression tended to describe more supportive home environments, and more compliant and introvert personality traits. Retrospective data collection and no corroborative evidence from other family members. No distinction was made between bipolar I and bipolar II disorder nor between melancholic and non-melancholic depression in the sample. Finally the study spanned over a 12-month period which does not allow for the possibility of diagnostic reassignment of some of the bipolar participants to the unipolar condition. These findings indicate that there may be benefits in combining both proximal and distal indicators in identifying a bipolar disorder phenotype which, in turn, may be relevant to the development of early intervention programs for young people with bipolar disorder.

  8. [Creativity and bipolar disorder].

    Science.gov (United States)

    Maçkalı, Zeynep; Gülöksüz, Sinan; Oral, Timuçin

    2014-01-01

    The relationship between creativity and bipolar disorder has been an intriguing topic since ancient times. Early studies focused on describing characteristics of creative people. From the last quarter of the twentieth century, researchers began to focus on the relationship between mood disorders and creativity. Initially, the studies were based on biographical texts and the obtained results indicated a relationship between these two concepts. The limitations of the retrospective studies led the researchers to develop systematic investigations into this area. The systematic studies that have focused on artistic creativity have examined both the prevalence of mood disorders and the creative process. In addition, a group of researchers addressed the relationship in terms of affective temperaments. Through the end of the 90's, the scope of creativity was widened and the notion of everyday creativity was proposed. The emergence of this notion led researchers to investigate the associations of the creative process in ordinary (non-artist) individuals. In this review, the descriptions of creativity and creative process are mentioned. Also, the creative process is addressed with regards to bipolar disorder. Then, the relationship between creativity and bipolar disorder are evaluated in terms of aforementioned studies (biographical, systematic, psychobiographical, affective temperaments). In addition, a new model, the "Shared Vulnerability Model" which was developed to explain the relationship between creativity and psychopathology is introduced. Finally, the methodological limitations and the suggestions for resolving these limitations are included.

  9. Bipolar Disorder and Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Sermin Kesebir

    2010-04-01

    Full Text Available Comorbid endocrine and cardiovascular situations with bipolar disorder usually result from the bipolar disorder itself or as a consequence of its treatment. With habits and lifestyle, genetic tendency and side effects, this situation is becoming more striking. Subpopulations of bipolar disorders patients should be considered at high risk for diabetes mellitus. The prevalence of diabetes mellitus in bipolar disorder may be three times greater than in the general population. Comorbidity of diabetes causes a pathophysiological overlapping in the neurobiological webs of bipolar cases. Signal mechanisms of glycocorticoid/insulin and immunoinflammatory effector systems are junction points that point out the pathophysiology between bipolar disorder and general medical cases susceptible to stress. Glycogen synthetase kinase (GSK-3 is a serine/treonine kinase and inhibits the transport of glucose stimulated by insulin. It is affected in diabetes, cancer, inflammation, Alzheimer disease and bipolar disorder. Hypoglycemic effect of lithium occurs via inhibiting glycogen synthetase kinase. When comorbid with diabetes, the other disease -for example bipolar disorder, especially during its acute manic episodes-, causes a serious situation that presents its influences for a lifetime. Choosing pharmacological treatment and treatment adherence are another important interrelated areas. The aim of this article is to discuss and review the etiological, clinical and therapeutic properties of diabetes mellitus and bipolar disorder comorbidity.

  10. A novel structure of a high current gain 4H-SiC BJT with a buried layer in the base

    Science.gov (United States)

    Zhang, You-Run; Zhang, Bo; Li, Zhao-Ji; Deng, Xiao-Chuan; Liu, Xi-Ling

    2009-09-01

    In this paper, a new structure of a 4H-SiC bipolar junction transistor (BJT) with a buried layer (BL) in the base is presented. The current gain shows an approximately 100% increase compared with that of the conventional structure. This is attributed to the creation of a built-in electric field for the minority carriers to transport in the base which is explained based on 2D device simulations. The optimized design of the buried layer region is also considered by numeric simulations.

  11. John Bardeen and transistor physics

    Science.gov (United States)

    Huff, Howard R.

    2001-01-01

    John Bardeen and Walter Brattain invented the point-contact semiconductor amplifier (transistor action) in polycrystalline germanium (also observed in polycrystalline silicon) on Dec. 15, 1947, for which they received a patent on Oct. 3, 1950. Bill Shockley was not a co-patent holder on Bardeen and Brattain's point-contact semiconductor amplifier patent since Julius Lilienfeld had already received a patent in 1930 for what would have been Shockley's contribution; namely, the field-effect methodology. Shockley received patents for both his minority-carrier injection concept and junction transistor theory, however, and deservedly shared the Nobel prize with Bardeen and Brattain for his seminal contributions of injection, p-n junction theory and junction transistor theory. We will review the events leading up to the invention of Bardeen and Brattain's point-contact semiconductor amplifier during the magic month of November 17-December 16, 1947 and the invention of Shockley's junction semiconductor amplifier during his magic month of December 24, 1947-January 23, 1948. It was during the course of Bardeen and Brattain's research in November, 1947 that Bardeen also patented the essence of the MOS transistor, wherein the induced minority carriers were confined to the inversion layer enroute to the collector. C. T. Sah has described this device as a sourceless MOS transistor. Indeed, John Bardeen, co-inventor of the point-contact semiconductor amplifier and inventor of the MOS transistor, may rightly be called the father of modern electronics.

  12. Bipolar disorder and neurophysiologic mechanisms

    Directory of Open Access Journals (Sweden)

    Simon M McCrea

    2008-11-01

    Full Text Available Simon M McCreaDepartments of Neurology and Neuroophthalmology, University of British Columbia, 2550 Willow Street, Vancouver, British Columbia, Canada V5Z 3N9Abstract: Recent studies have suggested that some variants of bipolar disorder (BD may be due to hyperconnectivity between orbitofrontal (OFC and temporal pole (TP structures in the dominant hemisphere. Some initial MRI studies noticed that there were corpus callosum abnormalities within specific regional areas and it was hypothesized that developmentally this could result in functional or effective connectivity changes within the orbitofrontal-basal ganglia-thalamocortical circuits. Recent diffusion tensor imaging (DTI white matter fiber tractography studies may well be superior to region of interest (ROI DTI in understanding BD. A “ventral semantic stream” has been discovered connecting the TP and OFC through the uncinate and inferior longitudinal fasciculi and the elusive TP is known to be involved in theory of mind and complex narrative understanding tasks. The OFC is involved in abstract valuation in goal and sub-goal structures and the TP may be critical in binding semantic memory with person–emotion linkages associated with narrative. BD patients have relative attenuation of performance on visuoconstructional praxis consistent with an atypical localization of cognitive functions. Multiple lines of evidence suggest that some BD alleles are being selected for which could explain the enhanced creativity in higher-ability probands. Associations between ROI’s that are not normally connected could explain the higher incidence of artistic aptitude, writing ability, and scientific achievements among some mood disorder subjects.Keywords: bipolar disorder, diffusion tensor imaging, white matter tractography, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, mood dysphoria, creativity, ventral semantic stream, writing ability, artistic aptitude

  13. Toward constructing an endophenotype strategy for bipolar disorders.

    Science.gov (United States)

    Hasler, Gregor; Drevets, Wayne C; Gould, Todd D; Gottesman, Irving I; Manji, Husseini K

    2006-07-15

    Research aimed at elucidating the underlying neurobiology and genetics of bipolar disorder, and factors associated with treatment response, have been limited by a heterogeneous clinical phenotype and lack of knowledge about its underlying diathesis. We used a survey of clinical, epidemiological, neurobiological, and genetic studies to select and evaluate candidate endophenotypes for bipolar disorder. Numerous findings regarding brain function, brain structure, and response to pharmacological challenge in bipolar patients and their relatives deserve further investigation. Candidate brain function endophenotypes include attention deficits, deficits in verbal learning and memory, cognitive deficits after tryptophan depletion, circadian rhythm instability, and dysmodulation of motivation and reward. We selected reduced anterior cingulate volume and early-onset white matter abnormalities as candidate brain structure endophenotypes. Symptom provocation endophenotypes might be based on bipolar patients' sensitivity to sleep deprivation, psychostimulants, and cholinergic drugs. Phenotypic heterogeneity is a major impediment to the elucidation of the neurobiology and genetics of bipolar disorder. We present a strategy constructed to improve the phenotypic definition of bipolar disorder by elucidating candidate endophenotypes. Studies to evaluate candidate endophenotypes with respect to specificity, heritability, temporal stability, and prevalence in unaffected relatives are encouraged.

  14. Fabrication and electrical characterization of homo- and hetero-structure Si/SiGe nanowire Tunnel Field Effect Transistor grown by vapor-liquid-solid mechanism

    Science.gov (United States)

    Brouzet, V.; Salem, B.; Periwal, P.; Alcotte, R.; Chouchane, F.; Bassani, F.; Baron, T.; Ghibaudo, G.

    2016-04-01

    We demonstrate the fabrication and electrical characterization of Ω -gate Tunnel Field Effect Transistors (TFET) based on p-Si/i-Si/n+Si0.7Ge0.3 heterostructure nanowires grown by Chemical Vapor Deposition (CVD) using the vapor-liquid-solid (VLS) mechanism. The electrical performances of the p-Si/i-Si/n+Si0.7Ge0.3 heterostructure TFET device are presented and compared to Si and Si0.7Ge0.3 homostructure nanowire TFETs. We observe an improvement of the electrical performances of TFET with p-Si/i-Si/n+Si0.7Ge0.3 heterostructure nanowire (HT NW). The optimized devices present an Ion current of about 245 nA at VDS = -0.5 V and VGS = -3 V with a subthreshold swing around 135 mV/dec. Finally, we show that the electrical results are in good agreement with numerical simulation using Kane's Band-to-Band Tunneling model.

  15. Non-monotonic magnetoresistance in an AlGaN/GaN high-electron-mobility transistor structure in the ballistic region

    Science.gov (United States)

    Wang, Yi-Ting; Woo, Tak-Pong; Lo, S.-T.; Kim, Gil-Ho; Liang, Chi-Te

    2014-05-01

    In this report, we will discuss the nonmonotonic magnetoresistance (MR) in an AlGaN/GaN high-electron-mobility transistor (HEMT) in a perpendicular magnetic field B in the ballistic region ( kBTτ/ħ constant, temperature, elastic scattering time, reduced Planck constant, Fermi wave vector and mean free path, respectively. The MR shows a local maximum between the weak localization (WL) and the Shubnikov-de Haas regions. In the low magnetic field regime, the quantum correction to the conductivity is proportional to T -3/2, which is consistent with a recent theory [T. A. Sedrakyan, and M. E. Raikh, Phys. Rev. Lett. 100, 106806 (2008)]. According to our results, as the temperature is increased, the position of the MR maximum in B increases. These results cannot be explained by present theories. Moreover, in the high-magnetic-field regime, neither the magnetic and nor the temperature dependences of the observed MR is consistent with present theories. We, therefore, suggest that while some features of the observed nonmonotonic MR can be successfully explained, further experimental and theoretical studies are necessary to obtain a thorough understanding of the MR effects.

  16. Cryogenic ultra-low-noise SiGe transistor amplifier.

    Science.gov (United States)

    Ivanov, B I; Trgala, M; Grajcar, M; Il'ichev, E; Meyer, H-G

    2011-10-01

    An ultra-low-noise one-stage SiGe heterojunction bipolar transistor amplifier was designed for cryogenic temperatures and a frequency range of 10 kHz-100 MHz. A noise temperature T(N) ≈ 1.4 K was measured at an ambient temperature of 4.2 K at frequencies between 100 kHz and 100 MHz for a source resistance of ~50 Ω. The voltage gain of the amplifier was 25 dB at a power consumption of 720 μW. The input voltage noise spectral density of the amplifier is about 35 pV/√Hz. The low noise resistance and power consumption makes the amplifier suitable for readout of resistively shunted DC SQUID magnetometers and amplifiers.

  17. Features of carrier tunneling between the silicon valence band and metal in devices based on the Al/high-K oxide/SiO{sub 2}/Si structure

    Energy Technology Data Exchange (ETDEWEB)

    Vexler, M. I., E-mail: shulekin@mail.ioffe.ru; Grekhov, I. V. [Russian Academy of Sciences, Ioffe Physical–Technical Institute (Russian Federation)

    2016-05-15

    The features of electron tunneling from or into the silicon valence band in a metal–insulator–semiconductor system with the HfO{sub 2}(ZrO{sub 2})/SiO{sub 2} double-layer insulator are theoretically analyzed for different modes. It is demonstrated that the valence-band current plays a less important role in structures with HfO{sub 2}(ZrO{sub 2})/SiO{sub 2} than in structures containing only silicon dioxide. In the case of a very wide-gap high-K oxide ZrO{sub 2}, nonmonotonic behavior related to tunneling through the upper barrier is predicted for the valence-band–metal current component. The use of an insulator stack can offer certain advantages for some devices, including diodes, bipolar tunnel-emitter transistors, and resonant-tunneling diodes, along with the traditional use of high-K insulators in a field-effect transistor.

  18. A clinical case-based hypothesis: secretory IgA operates as an electronic transistor controlling the selection or rejection of molecules in the absorption process in the lumen of gastrointestinal tract.

    Science.gov (United States)

    Zamm, Alfred V

    2013-01-01

    There is a clinical correlation between (1) an allergic patient's ability to resist the development of symptoms that would have resulted from an allergenic challenge, (2) the magnitude of geomagnetism at a geographic site, and (3) the amount of solar energy falling on that site. It is suggested that the digestive membrane has an electronic gatekeeper that "decides" electronically which molecules to allow or not allow to pass on to the absorptive surface. The unique bipolar structure of secretory immunoglobulin A (IgA), having a central secretory piece and the resultant unique electronic function of this polarized molecule, allows it to function as an electronic transistor, producing an electronic gatekeeper in the form of an electronic sieve.

  19. Growth of high mobility GaN and AlGaN/GaN high electron mobility transistor structures on 4H-SiC by ammonia molecular-beam epitaxy

    International Nuclear Information System (INIS)

    Webb, James B.; Tang, H.; Bardwell, J. A.; Coleridge, P.

    2001-01-01

    Ammonia molecular-beam epitaxy has been used to grow high-quality epilayers of GaN and AlGaN/GaN heterostructure field-effect transistor (HFET) structures on insulating 4H-SiC. The growth process, which used a magnetron sputter epitaxy deposited buffer layer of AlN, has been described previously. Ex situ pretreatment of the SiC substrate was found to be unnecessary. For a single 2.0 μm thick silicon doped epilayer, a room temperature (RT) electron mobility of 500 cm2/Vs was measured at a carrier density of 6.6x10 16 cm -3 . For the HFET structure, a room temperature mobility of 1300 cm2/Vs at a sheet carrier density of 3.3x10 12 cm -2 was observed, increasing to 11000 cm2/Vs at 77 K. The surface morphology of the layers indicated a coalesced mesa structure similar to what we observed for growth on sapphire, but with a lower overall defect density and correspondingly larger grain size. The observation of well-resolved Shubnikov de Haas oscillations at fields as low as 3 T indicated a relatively smooth interface. [copyright] 2001 American Institute of Physics

  20. Hafnium transistor process design for neural interfacing.

    Science.gov (United States)

    Parent, David W; Basham, Eric J

    2009-01-01

    A design methodology is presented that uses 1-D process simulations of Metal Insulator Semiconductor (MIS) structures to design the threshold voltage of hafnium oxide based transistors used for neural recording. The methodology is comprised of 1-D analytical equations for threshold voltage specification, and doping profiles, and 1-D MIS Technical Computer Aided Design (TCAD) to design a process to implement a specific threshold voltage, which minimized simulation time. The process was then verified with a 2-D process/electrical TCAD simulation. Hafnium oxide films (HfO) were grown and characterized for dielectric constant and fixed oxide charge for various annealing temperatures, two important design variables in threshold voltage design.

  1. The impact of bipolar depression.

    Science.gov (United States)

    Post, Robert M

    2005-01-01

    Bipolar disorder is a chronic, intermittent illness that is associated with high morbidity and mortality. In addition, patients with bipolar disorder often have comorbid psychiatric conditions (such as anxiety disorders, alcohol or substance abuse, and eating disorders) or medical disorders (such as obesity), which result in increased burden of illness for the patients, family members, and treating clinicians. Although bipolar disorder consists of recurring episodes of mania and depression, patients spend more time depressed than manic. Bipolar depression is associated with a greater risk of suicide and of impairment in work, social, or family life than mania. This health burden also results in direct and indirect economic costs to the individual and society at large. Bipolar depression is often undiagnosed or misdiagnosed as unipolar depression, resulting in incorrect or inadequate treatment. Available treatments for bipolar depression include medications such as lithium, selected anticonvulsants, and the atypical antipsychotics. Traditional antidepressants are not recommended as monotherapy for bipolar depression as they can induce switching to mania. Early and accurate diagnosis, aggressive management, and earlier prophylactic treatment regimens are needed to overcome the impact of depressive episodes in patients with bipolar disorder.

  2. Reconfigurable quadruple quantum dots in a silicon nanowire transistor

    Energy Technology Data Exchange (ETDEWEB)

    Betz, A. C., E-mail: ab2106@cam.ac.uk; Broström, M.; Gonzalez-Zalba, M. F. [Hitachi Cambridge Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Tagliaferri, M. L. V. [Laboratorio MDM, CNR-IMM, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Dipartimento di Scienza dei Materiali, Universit di Milano-Bicocca, Via Cozzi 53, 20125 Milano (Italy); Vinet, M. [CEA/LETI-MINATEC, CEA-Grenoble, 17 rue des martyrs, F-38054 Grenoble (France); Sanquer, M. [SPSMS, UMR-E CEA/UJF-Grenoble 1, INAC, 17 rue des Martyrs, 38054 Grenoble (France); Ferguson, A. J. [Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE (United Kingdom)

    2016-05-16

    We present a reconfigurable metal-oxide-semiconductor multi-gate transistor that can host a quadruple quantum dot in silicon. The device consists of an industrial quadruple-gate silicon nanowire field-effect transistor. Exploiting the corner effect, we study the versatility of the structure in the single quantum dot and the serial double quantum dot regimes and extract the relevant capacitance parameters. We address the fabrication variability of the quadruple-gate approach which, paired with improved silicon fabrication techniques, makes the corner state quantum dot approach a promising candidate for a scalable quantum information architecture.

  3. Reconfigurable quadruple quantum dots in a silicon nanowire transistor

    International Nuclear Information System (INIS)

    Betz, A. C.; Broström, M.; Gonzalez-Zalba, M. F.; Tagliaferri, M. L. V.; Vinet, M.; Sanquer, M.; Ferguson, A. J.

    2016-01-01

    We present a reconfigurable metal-oxide-semiconductor multi-gate transistor that can host a quadruple quantum dot in silicon. The device consists of an industrial quadruple-gate silicon nanowire field-effect transistor. Exploiting the corner effect, we study the versatility of the structure in the single quantum dot and the serial double quantum dot regimes and extract the relevant capacitance parameters. We address the fabrication variability of the quadruple-gate approach which, paired with improved silicon fabrication techniques, makes the corner state quantum dot approach a promising candidate for a scalable quantum information architecture.

  4. Planar transistors and impatt diodes with ion implantation

    International Nuclear Information System (INIS)

    Dorendorf, H.; Glawischnig, H.; Grasser, L.; Hammerschmitt, J.

    1975-03-01

    Low frequency planar npn and pnp transistors have been developed in which the base and emitter have been fabricated using ion implantation of boron and phosphorus by a drive-in diffusion. Electrical parameters of the transistors are comparable with conventionally produced transistors; the noise figure was improved and production tolerances were significantly reduced. Silicon-impatt diodes for the microwave range were also fabricated with implanted pn junctions and tested for their high frequency characteristics. These diodes, made in an improved upside down technology, delivered output power up to 40 mW (burn out power) at 30 GHz. Reverse leakage current and current carrying capability of these diodes were comparable to diffused structures. (orig.) 891 ORU 892 MB [de

  5. Scientific attitudes towards bipolar disorders

    Directory of Open Access Journals (Sweden)

    Mohammad-Hossein Biglu

    2014-02-01

    Full Text Available Introduction: Bipolar disorder is a psychiatric condition that is also called manic-depressive disease. It causes unusual changes in mood, energy, activity levels, and the ability to carry out day-to-day tasks. In the present study, 3 sets of data were considered and analyzed: first, all papers categorized under Bipolar Disorders in Science Citation Index Expanded (SCI-E database through 2001-2011; second, papers published by the international journal of Bipolar Disorders indexed in SCI-E during a period of 11 years; and third, all papers distributed by the international journal of Bipolar Disorders indexed in MEDLINE during the period of study. Methods: The SCI-E database was used to extract all papers indexed with the topic of Bipolar Disorders as well as all papers published by The International Journal of Bipolar Disorders. Extraction of data from MEDLINE was restricted to the journals name from setting menu. The Science of Science Tool was used to map the co-authorship network of papers published by The International Journal of Bipolar Disorders through 2009-2011. Results: Analysis of data showed that the majority of publications in the subject area of bipolar disorders indexed in SCI-E were published by The International Journal of Bipolar Disorders. Although journal articles consisted of 59% of the total publication type in SCI-E, 65% of publications distributed by The Journal of Bipolar Disorders were in the form of meetingabstracts. Journal articles consisted of only 23% of the total publications. USA was the leading country regarding sharing data in the field of bipolar disorders followed by England, Canada, and Germany. Conclusion: The editorial policy of The International Journal of Bipolar Disorders has been focused on new themes and new ways of researching in the subject area of bipolar disorder. Regarding the selection of papers for indexing, the SCI-E database selects data more comprehensively than MEDLINE. The number of papers

  6. Diakoptical reliability analysis of transistorized systems

    International Nuclear Information System (INIS)

    Kontoleon, J.M.; Lynn, J.W.; Green, A.E.

    1975-01-01

    Limitations both on high-speed core availability and computation time required for assessing the reliability of large-sized and complex electronic systems, such as used for the protection of nuclear reactors, are very serious restrictions which continuously confront the reliability analyst. Diakoptic methods simplify the solution of the electrical-network problem by subdividing a given network into a number of independent subnetworks and then interconnecting the solutions of these smaller parts by a systematic process involving transformations based on connection-matrix elements associated with the interconnecting links. However, the interconnection process is very complicated and it may be used only if the original system has been cut in such a manner that a relation can be established between the constraints appearing at both sides of the cut. Also, in dealing with transistorized systems, one of the difficulties encountered is that of modelling adequately their performance under various operating conditions, since their parameters are strongly affected by the imposed voltage and current levels. In this paper a new interconnection approach is presented which may be of use in the reliability analysis of large-sized transistorized systems. This is based on the partial optimization of the subdivisions of the torn network as well as on the optimization of the torn paths. The solution of the subdivisions is based on the principles of algebraic topology, with an algebraic structure relating the physical variables in a topological structure which defines the interconnection of the discrete elements. Transistors, and other nonlinear devices, are modelled using their actual characteristics, under normal and abnormal operating conditions. Use of so-called k factors is made to facilitate accounting for use of electrical stresses. The approach is demonstrated by way of an example. (author)

  7. BUSFET - A Novel Radiation-Hardened SOI Transistor

    International Nuclear Information System (INIS)

    Dodd, P.E.; Draper, B.L.; Schwank, J.R.; Shaneyfelt, M.R.

    1999-01-01

    A partially-depleted SOI transistor structure has been designed that does not require the use of specially-processed hardened buried oxides for total-dose hardness and maintains the intrinsic SEU and dose rate hardness advantages of SOI technology

  8. Nanoscaled biological gated field effect transistors for cytogenetic analysis

    DEFF Research Database (Denmark)

    Kwasny, Dorota; Dimaki, Maria; Andersen, Karsten Brandt

    2014-01-01

    Cytogenetic analysis is the study of chromosome structure and function, and is often used in cancer diagnosis, as many chromosome abnormalities are linked to the onset of cancer. A novel label free detection method for chromosomal translocation analysis using nanoscaled field effect transistors...

  9. Logarithmic current-measuring transistor circuits

    DEFF Research Database (Denmark)

    Højberg, Kristian Søe

    1967-01-01

    Describes two transistorized circuits for the logarithmic measurement of small currents suitable for nuclear reactor instrumentation. The logarithmic element is applied in the feedback path of an amplifier, and only one dual transistor is used as logarithmic diode and temperature compensating...... transistor. A simple one-amplifier circuit is compared with a two-amplifier system. The circuits presented have been developed in connexion with an amplifier using a dual m.o.s. transistor input stage with diode-protected gates....

  10. Novel multiple criteria decision making methods based on bipolar neutrosophic sets and bipolar neutrosophic graphs

    OpenAIRE

    Muhammad, Akram; Musavarah, Sarwar

    2016-01-01

    In this research study, we introduce the concept of bipolar neutrosophic graphs. We present the dominating and independent sets of bipolar neutrosophic graphs. We describe novel multiple criteria decision making methods based on bipolar neutrosophic sets and bipolar neutrosophic graphs. We also develop an algorithm for computing domination in bipolar neutrosophic graphs.

  11. The functional neuroanatomy of bipolar disorder: a consensus model

    Science.gov (United States)

    Strakowski, Stephen M; Adler, Caleb M; Almeida, Jorge; Altshuler, Lori L; Blumberg, Hilary P; Chang, Kiki D; DelBello, Melissa P; Frangou, Sophia; McIntosh, Andrew; Phillips, Mary L; Sussman, Jessika E; Townsend, Jennifer D

    2013-01-01

    Objectives Functional neuroimaging methods have proliferated in recent years, such that functional magnetic resonance imaging, in particular, is now widely used to study bipolar disorder. However, discrepant findings are common. A workgroup was organized by the Department of Psychiatry, University of Cincinnati (Cincinnati, OH, USA) to develop a consensus functional neuroanatomic model of bipolar I disorder based upon the participants’ work as well as that of others. Methods Representatives from several leading bipolar disorder neuroimaging groups were organized to present an overview of their areas of expertise as well as focused reviews of existing data. The workgroup then developed a consensus model of the functional neuroanatomy of bipolar disorder based upon these data. Results Among the participants, a general consensus emerged that bipolar I disorder arises from abnormalities in the structure and function of key emotional control networks in the human brain. Namely, disruption in early development (e.g., white matter connectivity, prefrontal pruning) within brain networks that modulate emotional behavior leads to decreased connectivity among ventral prefrontal networks and limbic brain regions, especially amygdala. This developmental failure to establish healthy ventral prefrontal–limbic modulation underlies the onset of mania and ultimately, with progressive changes throughout these networks over time and with affective episodes, a bipolar course of illness. Conclusions This model provides a potential substrate to guide future investigations and areas needing additional focus are identified. PMID:22631617

  12. Three dimensional-stacked complementary thin-film transistors using n-type Al:ZnO and p-type NiO thin-film transistors.

    Science.gov (United States)

    Lee, Ching-Ting; Chen, Chia-Chi; Lee, Hsin-Ying

    2018-03-05

    The three dimensional inverters were fabricated using novel complementary structure of stacked bottom n-type aluminum-doped zinc oxide (Al:ZnO) thin-film transistor and top p-type nickel oxide (NiO) thin-film transistor. When the inverter operated at the direct voltage (V DD ) of 10 V and the input voltage from 0 V to 10 V, the obtained high performances included the output swing of 9.9 V, the high noise margin of 2.7 V, and the low noise margin of 2.2 V. Furthermore, the high performances of unskenwed inverter were demonstrated by using the novel complementary structure of the stacked n-type Al:ZnO thin-film transistor and p-type nickel oxide (NiO) thin-film transistor.

  13. Electronic Model of a Ferroelectric Field Effect Transistor

    Science.gov (United States)

    MacLeod, Todd C.; Ho, Fat Duen; Russell, Larry (Technical Monitor)

    2001-01-01

    A pair of electronic models has been developed of a Ferroelectric Field Effect transistor. These models can be used in standard electrical circuit simulation programs to simulate the main characteristics of the FFET. The models use the Schmitt trigger circuit as a basis for their design. One model uses bipolar junction transistors and one uses MOSFET's. Each model has the main characteristics of the FFET, which are the current hysterisis with different gate voltages and decay of the drain current when the gate voltage is off. The drain current from each model has similar values to an actual FFET that was measured experimentally. T'he input and o Output resistance in the models are also similar to that of the FFET. The models are valid for all frequencies below RF levels. No attempt was made to model the high frequency characteristics of the FFET. Each model can be used to design circuits using FFET's with standard electrical simulation packages. These circuits can be used in designing non-volatile memory circuits and logic circuits and is compatible with all SPICE based circuit analysis programs. The models consist of only standard electrical components, such as BJT's, MOSFET's, diodes, resistors, and capacitors. Each model is compared to the experimental data measured from an actual FFET.

  14. High-Performance Solution-Deposited Ambipolar Organic Transistors Based on Terrylene Diimides

    DEFF Research Database (Denmark)

    Liu, Chuan; Liu, Zhihong; Lemke, Henrik T.

    2010-01-01

    The thin film transistor characteristics of a soluble molecular semiconductor, terrylene tetracarboxdiimide (TDI), a homologue of perylene tetracarboxdiimide (PDI), have been investigated. In a bottom-gate device structure with benzocyclobutene gate dielectric, n-type behavior with electron mobil...

  15. Analogy of transistor function with modulating photonic band gap in electromagnetically induced grating.

    Science.gov (United States)

    Wang, Zhiguo; Ullah, Zakir; Gao, Mengqin; Zhang, Dan; Zhang, Yiqi; Gao, Hong; Zhang, Yanpeng

    2015-09-09

    Optical transistor is a device used to amplify and switch optical signals. Many researchers focus on replacing current computer components with optical equivalents, resulting in an optical digital computer system processing binary data. Electronic transistor is the fundamental building block of modern electronic devices. To replace electronic components with optical ones, an equivalent optical transistor is required. Here we compare the behavior of an optical transistor with the reflection from a photonic band gap structure in an electromagnetically induced transparency medium. A control signal is used to modulate the photonic band gap structure. Power variation of the control signal is used to provide an analogy between the reflection behavior caused by modulating the photonic band gap structure and the shifting of Q-point (Operation point) as well as amplification function of optical transistor. By means of the control signal, the switching function of optical transistor has also been realized. Such experimental schemes could have potential applications in making optical diode and optical transistor used in quantum information processing.

  16. Bipolar pulse forming line

    Science.gov (United States)

    Rhodes, Mark A.

    2008-10-21

    A bipolar pulse forming transmission line module for linear induction accelerators having first, second, third, fourth, and fifth planar conductors which form an interleaved stack with dielectric layers between the conductors. Each conductor has a first end, and a second end adjacent an acceleration axis. The first and second planar conductors are connected to each other at the second ends, the fourth and fifth planar conductors are connected to each other at the second ends, and the first and fifth planar conductors are connected to each other at the first ends via a shorting plate adjacent the first ends. The third planar conductor is electrically connectable to a high voltage source, and an internal switch functions to short a high voltage from the first end of the third planar conductor to the first end of the fourth planar conductor to produce a bipolar pulse at the acceleration axis with a zero net time integral. Improved access to the switch is enabled by an aperture through the shorting plate and the proximity of the aperture to the switch.

  17. Transistor challenges - A DRAM perspective

    International Nuclear Information System (INIS)

    Faul, Juergen W.; Henke, Dietmar

    2005-01-01

    Key challenges of the transistor scaling from a DRAM perspective will be reviewed. Both, array transistors as well as DRAM support devices face challenges that differ essentially from high performance logic device scaling. As a major difference, retention time and standby current requirements characterize special boundary conditions in the DRAM device design. Array device scaling is determined by a chip size driven aggressive node scaling. To continue scaling, major innovations need to be introduced into state-of-the-art planar array transistors. Alternatively, non planar device concepts will have to be evaluated. Support device design for DRAMs is driven by today's market demand for increased chip performances at little to no extra cost. Major innovations are required to continue that path. Besides this strive for performance increase, special limitations for 'on pitch' circuits at the array edge will come up due to the aggressive cell size scaling

  18. Tunneling field effect transistor technology

    CERN Document Server

    Chan, Mansun

    2016-01-01

    This book provides a single-source reference to the state-of-the art in tunneling field effect transistors (TFETs). Readers will learn the TFETs physics from advanced atomistic simulations, the TFETs fabrication process and the important roles that TFETs will play in enabling integrated circuit designs for power efficiency. · Provides comprehensive reference to tunneling field effect transistors (TFETs); · Covers all aspects of TFETs, from device process to modeling and applications; · Enables design of power-efficient integrated circuits, with low power consumption TFETs.

  19. A high performance charge plasma PN-Schottky collector transistor on silicon-on-insulator

    Science.gov (United States)

    Loan, Sajad A.; Bashir, Faisal; Rafat, M.; Alamoud, Abdul Rehman M.; Abbasi, Shuja A.

    2014-09-01

    In this paper, we propose a new high performance PN-Schottky collector (PN-SC) lateral bipolar junction transistor (BJT) on silicon-on-insulator (SOI). The proposed device addresses the problem of poor speed of conventional lateral PNP-BJT device by using a Schottky collector. Further, it does not use the conventional ways of ion implantation/diffusion to realize n and p type doped region. However, it uses metal electrodes of different work functions to create n and p type charge plasma in an undoped silicon film. The simulation study of the proposed lateral PN-SC bipolar charge plasma transistor on SOI (PN-SC-BCPT) device has shown a significant improvement in current gain (β), cutoff frequency (f T) and switching performance in comparison to conventional PNP-BJT and PNP-bipolar charge plasma transistor (PNP-BCPT) devices. A significantly high β is obtained in the proposed PN-SC-BCPT (˜2100) in comparison to PNP-BCPT (˜1450) and the conventional BJT (˜9) devices, respectively. It has been observed that there is 89.56% and 153.5% increase in f T for the proposed PN-SC-BCPT device (2.18 GHz) in comparison to conventional PNP-BJT (1.15 GHz) and PNP-BCPT (0.86 GHz) devices, respectively. Further, reductions of 24.6% and 15.4% in switching ON-delay and 66% and 30.76% in switching OFF-delay have been achieved in the proposed device based inverters in comparison to PNP-BCPT and the conventional BJT devices based inverters, respectively. Furthermore, the proposed device does not face doping related issues and the requirement of high temperature processing is absent.

  20. A bipolar analog front-end integrated circuit for the SDC silicon tracker

    International Nuclear Information System (INIS)

    Kipnis, I.; Spieler, H.; Collins, T.

    1993-11-01

    A low-noise, low-power, high-bandwidth, radiation hard, silicon bipolar-transistor full-custom integrated circuit (IC) containing 64 channels of analog signal processing has been developed for the SDC silicon tracker. The IC was designed and tested at LBL and was fabricated using AT ampersand T's CBIC-U2, 4 GHz f T complementary bipolar technology. Each channel contains the following functions: low-noise preamplification, pulse shaping and threshold discrimination. This is the first iteration of the production analog IC for the SDC silicon tracker. The IC is laid out to directly match the 50 μm pitch double-sided silicon strip detector. The chip measures 6.8 mm x 3.1 mm and contains 3,600 transistors. Three stages of amplification provide 180 mV/fC of gain with a 35 nsec peaking time at the comparator input. For a 14 pF detector capacitance, the equivalent noise charge is 1300 el. rms at a power consumption of 1 mW/channel from a single 3.5 V supply. With the discriminator threshold set to 4 times the noise level, a 16 nsec time-walk for 1.25 to 10fC signals is achieved using a time-walk compensation network. Irradiation tests at TRIUMF to a Φ=10 14 protons/cm 2 have been performed on the IC, demonstrating the radiation hardness of the complementary bipolar process