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Sample records for gaas bipolar transistor

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  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. 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.

  10. 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.

  11. 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.

  12. 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.

  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. 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

  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. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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.

  3. 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)

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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…

  10. 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…

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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

  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. 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.

  20. 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.

  1. 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.

  2. 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...

  3. 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...

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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)

  10. Prediction of the threshold voltage of GaAs ion-implanted metal-semiconductor field-effect transistors

    Directory of Open Access Journals (Sweden)

    Gorev N. B.

    2007-12-01

    Full Text Available It is shown that the threshold voltage of a GaAs ion-implanted metal-semiconductor field-effect transistor corresponds with a good accuracy to the voltage at which an inflection point appears in the capacitance-voltage characteristic. A method for predicting the threshold voltage of ion-implanted field-effect transistors using capacitance-voltage measurements prior to contact formation is proposed.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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....

  17. 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.

  18. 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

  19. Preliminary measurements of gamma ray effects on characteristics of broad-band GaAs field-effect transistor preamplifiers

    International Nuclear Information System (INIS)

    Jackson, H.G.; Shimizu, T.T.; Leskovar, B.

    1985-01-01

    The effect of gamma radiation on electrical characteristics of cryogenically cooled broad-band low-noise microwave preamplifiers has been preliminarily evaluated. The change in the gain and noise figure of a 1-2 GHz preamplifier using GaAs microwave transistors was determined at gamma doses between 10 5 rad to 5 /times/ 10 8 rad. The gain and noise figure was measured at ambient temperatures of 300 K and 80 K. 8 refs., 2 figs

  20. 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

  1. 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.

  2. 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…

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. 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...

  17. 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.

  18. 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.

  19. 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...

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Analysis of the damage threshold of the GaAs pseudomorphic high electron mobility transistor induced by the electromagnetic pulse

    Science.gov (United States)

    Xi, Xiao-Wen; Chai, Chang-Chun; Liu, Yang; Yang, Yin-Tang; Fan, Qing-Yang; Shi, Chun-Lei

    2016-08-01

    An electromagnetic pulse (EMP)-induced damage model based on the internal damage mechanism of the GaAs pseudomorphic high electron mobility transistor (PHEMT) is established in this paper. With this model, the relationships among the damage power, damage energy, pulse width and signal amplitude are investigated. Simulation results show that the pulse width index from the damage power formula obtained here is higher than that from the empirical formula due to the hotspot transferring in the damage process of the device. It is observed that the damage energy is not a constant, which decreases with the signal amplitude increasing, and then changes little when the signal amplitude reaches up to a certain level. Project supported by the National Basic Research Program of China (Grant No. 2014CB339900) and the Open Fund of Key Laboratory of Complex Electromagnetic Environment Science and Technology, China Academy of Engineering Physics (CAEP) (Grant No. 2015-0214.XY.K).

  20. Damage effect and mechanism of the GaAs high electron mobility transistor induced by high power microwave

    Science.gov (United States)

    Yang, Liu; Chang-Chun, Chai; Yin-Tang, Yang; Jing, Sun; Zhi-Peng, Li

    2016-04-01

    In this paper, we present the damage effect and mechanism of high power microwave (HPM) on AlGaAs/GaAs pseudomorphic high-electron-mobility transistor (pHEMT) of low-noise amplifier (LNA). A detailed investigation is carried out by simulation and experiment study. A two-dimensional electro-thermal model of the typical GaAs pHEMT induced by HPM is established in this paper. The simulation result reveals that avalanche breakdown, intrinsic excitation, and thermal breakdown all contribute to damage process. Heat accumulation occurs during the positive half cycle and the cylinder under the gate near the source side is most susceptible to burn-out. Experiment is carried out by injecting high power microwave into GaAs pHEMT LNA samples. It is found that the damage to LNA is because of the burn-out at first stage pHEMT. The interiors of the damaged samples are observed by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). Experimental results accord well with the simulation of our model. Project supported by the National Basic Research Program of China (Grant No. 2014CB339900) and the Open Fund of Key Laboratory of Complex Electromagnetic Environment Science and Technology, China Academy of Engineering Physics (Grant No. 2015-0214.XY.K).

  1. 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.

  2. 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.

  3. 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.

  4. 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%.

  5. 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

  6. Design and characterisation of high electron mobility transistors for use in a monolithic GaAs X-ray imaging sensor

    International Nuclear Information System (INIS)

    Boardman, D.A.; Sellin, P.J.

    2001-01-01

    A new design of monolithic GaAs pixel detector is proposed for medical and synchrotron applications. In this device a semi-insulating GaAs wafer will be used as both the detector element and the substrate for the integrated charge readout matrix. The charge readout matrix consists of High Electron Mobility Transistors (HEMTs), which are grown epitaxially onto the GaAs substrate. Experimental characterisation of HEMTs has been carried out and their suitability for the proposed imaging device is assessed. Temperature measurements on initial devices showed the threshold voltage to be stable from room temperature down to -15 degree sign C. HEMT designs with lower leakage current that operate in enhancement mode have been fabricated and modelled using the Silvaco simulation package. These optimised devices have been fabricated using a gate recess, and exhibit enhancement mode operation and significantly reduced gate leakage currents

  7. 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.

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 75-GHz SiGe Heterojunction Bipolor Transistors: GaAs Performance in Si Technology?

    Science.gov (United States)

    1992-05-22

    frequency results of the base-collector junction without penalty on cur- SiGe and Si epitaxial base transistors (cf. Figs. I and rent density...0.60x.3 0.604.3 20 / IT (GHz) 2, 2o . .. 50A SI BJT R(W/Ob) 3.8 s 10 k (0) 60 so’ ’ . . Re (a) is 1985 1990 R (0I) 18 8 Publication Date 0VCE0 M 2.4 3.2...ee ls "SIMS profile for the SiGe-base transistors of 0Fig. 1, The Ge grading is positioned precisely 20 in the most heavily doped region of the base NC

  20. Damage effect and mechanism of the GaAs pseudomorphic high electron mobility transistor induced by the electromagnetic pulse

    Science.gov (United States)

    Xiao-Wen, Xi; Chang-Chun, Chai; Gang, Zhao; Yin-Tang, Yang; Xin-Hai, Yu; Yang, Liu

    2016-04-01

    The damage effect and mechanism of the electromagnetic pulse (EMP) on the GaAs pseudomorphic high electron mobility transistor (PHEMT) are investigated in this paper. By using the device simulation software, the distributions and variations of the electric field, the current density and the temperature are analyzed. The simulation results show that there are three physical effects, i.e., the forward-biased effect of the gate Schottky junction, the avalanche breakdown, and the thermal breakdown of the barrier layer, which influence the device current in the damage process. It is found that the damage position of the device changes with the amplitude of the step voltage pulse. The damage appears under the gate near the drain when the amplitude of the pulse is low, and it also occurs under the gate near the source when the amplitude is sufficiently high, which is consistent with the experimental results. Project supported by the National Basic Research Program of China (Grant No. 2014CB339900), and the Open Fund of Key Laboratory of Complex Electromagnetic Environment Science and Technology, China Academy of Engineering Physics (CAEP) (Grant No. 2015-0214.XY.K).

  1. 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.

  2. 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

  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. Comparison of phonon scattering in nanowire field effect transistors with Si, GaAs and InGaAs cores using the NEGF formalism

    Science.gov (United States)

    Price, A.; Martinez, A.

    2015-10-01

    Using the Non-equilibrium Green's Function (NEGF) formalism, the impact of electron- phonon scattering on the performance of different core nanowire field effect transistors (NWFETs) has been investigated. Three core materials have been considered: Si, GaAs and InGaAs. The effective mass approximation has been used, with masses extracted from tight- binding simulations. The ID-VG characteristics at low and high drain bias are shown. It was found that at low drain bias, scattering caused a 86%, 72% and 50% percentage reduction in the current at high gate bias in the Si, GaAs and InGaAs core, 2.2 × 2.2 nm2 cross-section NWFETs respectively. The phonon-limited mobility and percentage tunnelling have also been calculated.

  5. 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

  6. 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.

  7. 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).

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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)

  15. 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

  16. 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.

  17. 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)

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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]).

  5. 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.

  6. 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.

  7. 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

  8. 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).

  9. 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.

  10. 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.

  11. 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.

  12. Effective mass approximation versus full atomistic model to calculate the output characteristics of a gate-all-around germanium nanowire field effect transistor (GAA-GeNW-FET)

    Science.gov (United States)

    Bayani, Amir Hossein; Voves, Jan; Dideban, Daryoosh

    2018-01-01

    Here, we compare the output characteristics of a gate-all-around germanium nanowire field effect transistor (GAA-GeNW-FET) with 2.36 nm2 square cross-section area using tight-binding (TB) sp3d5s∗ model (full atomistic model (FAM)) and effective mass approximation (EMA). Synopsys/QuantumWise Atomistix ToolKit (ATK) and Silvaco Atlas3D are used to consider the TB model and EMA, respectively. Results show that EMA predicted only one quantum state (QS) for quantum transport, whereas FAM predicted three QSs. A cosine function behavior is obtained by both methods for the first quantum state. The calculated bandgap value by EMA is almost twice smaller than that of the FAM. Also, a fluctuating current is predicted by both methods but in different oscillation values.

  13. 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.

  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. 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.

  16. 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.

  17. 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)

  18. 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.

  19. 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)

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. Investigation on phonon scattering in a GaAs nanowire field effect transistor using the non-equilibrium Green's function formalism

    Energy Technology Data Exchange (ETDEWEB)

    Price, A., E-mail: A.C.PRICE.625036@swansea.ac.uk; Martinez, A. [College of Engineering, Swansea University, Swansea (United Kingdom)

    2015-04-28

    Using quantum transport simulations, the impact of electron-phonon scattering on the transfer characteristic of a gate-all-around nanowire (GaAs) field effect transistor (NWFET) has been thoroughly investigated. The Non-Equilibrium Green's Function formalism in the effective mass approximation using a decoupled mode decomposition has been deployed. NWFETs of different dimensions have been considered, and scattering mechanisms including acoustic, optical and polar optical phonons have been included. The effective masses were extracted from tight binding simulations. High and low drain bias have been considered. We found substantial source to drain tunnelling current and significant impact of phonon scattering on the performance of the NWFET. At low drain bias, for a 2.2 × 2.2 nm{sup 2} cross-section transistor, scattering caused a 72%, 77%, and 81% decrease in the on-current for a 6 nm, 10 nm, and 20 nm channel length, respectively. This reduction in the current due to scattering is influenced by the increase in the tunnelling current. We include the percentage tunnelling for each valley at low and high drain bias. It was also found that the strong quantisation caused the relative position of the valleys to vary with the cross-section. This had a large effect on the overall tunnelling current. The phonon-limited mobility was also calculated, finding a mobility of 950 cm{sup 2}/V s at an inversion charge density of 10{sup 12 }cm{sup −2} for a 4.2 × 4.2 nm{sup 2} cross-section device.

  11. Investigation on phonon scattering in a GaAs nanowire field effect transistor using the non-equilibrium Green's function formalism

    Science.gov (United States)

    Price, A.; Martinez, A.

    2015-04-01

    Using quantum transport simulations, the impact of electron-phonon scattering on the transfer characteristic of a gate-all-around nanowire (GaAs) field effect transistor (NWFET) has been thoroughly investigated. The Non-Equilibrium Green's Function formalism in the effective mass approximation using a decoupled mode decomposition has been deployed. NWFETs of different dimensions have been considered, and scattering mechanisms including acoustic, optical and polar optical phonons have been included. The effective masses were extracted from tight binding simulations. High and low drain bias have been considered. We found substantial source to drain tunnelling current and significant impact of phonon scattering on the performance of the NWFET. At low drain bias, for a 2.2 × 2.2 nm2 cross-section transistor, scattering caused a 72%, 77%, and 81% decrease in the on-current for a 6 nm, 10 nm, and 20 nm channel length, respectively. This reduction in the current due to scattering is influenced by the increase in the tunnelling current. We include the percentage tunnelling for each valley at low and high drain bias. It was also found that the strong quantisation caused the relative position of the valleys to vary with the cross-section. This had a large effect on the overall tunnelling current. The phonon-limited mobility was also calculated, finding a mobility of 950 cm2/V s at an inversion charge density of 1012 cm-2 for a 4.2 × 4.2 nm2 cross-section device.

  12. 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.

  13. 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.

  14. 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...

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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).

  20. 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.

  1. 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.

  2. Perturbative vs non-perturbative impurity scattering in a narrow Si nanowire GAA transistor: A NEGF study

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Antonio; Brown, Andrew R; Seoane, Natalia; Asenov, Asen, E-mail: antonio@elec.gla.ac.u [Department Electronics and Electrical Engineering, University of Glasgow, G12 8LT (United Kingdom)

    2009-11-15

    In this paper we study the effect of impurity scattering on the performance of a Si gate-all-around nanowire transistors. The non-equilibrium Green function formalism is used in order to describe the carrier transport. Impurity scattering is introduced using two different formalisms, one that considers the impurity potential as a small perturbation by introducing self energies and the other in which the impurity potential is described exactly by included the impurity potential through the Poisson equation. The non-perturbative method does not use a fitting parameter but the perturbative one uses a phenomenological constant that can be calibrated to match the result of the non-perturbative method. We confirm Ohms-law-type behaviour by using the perturbative approach for larger channel lengths.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. Technology computer aided design for Si, SiGe and GaAs integrated circuits

    CERN Document Server

    Armstrong, GA

    2007-01-01

    The first book to deal with a broad spectrum of process and device design, and modelling issues related to semiconductor devices, bridging the gap between device modelling and process design using TCAD. Examples for types of Si-, SiGe-, GaAs- and InP-based heterostructure MOS and bipolar transistors are compared with experimental data from state-of-the-art devices. With various aspects of silicon heterostructures, this book presents a comprehensive perspective of emerging fields and covers topics ranging from materials to fabrication, devices, modelling and applications. Aimed at research-and-

  11. 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.

  12. 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)

  13. 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.

  14. 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.

  15. 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%.

  16. 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.

  17. Minority electron mobilities in GaAs, In0.53Ga0.47As, and GaAs0.50Sb0.50 calculated within an ensemble Monte Carlo model

    Science.gov (United States)

    Tea, E.; Aniel, F.

    2011-02-01

    The minority electron transport is crucial for the performances of heterojunction bipolar transistors (HBTs). Among the III-V semiconductors family, GaAsSb exhibits several advantages making it a serious candidate for the new generation of high speed HBTs. However, this alloy suffers from a lack of experimental studies. Properties such as electronic structure and charge carrier mobilities are of prime importance in theoretical device operation calculations. In this article, we investigate the minority electron mobilities by means of an ensemble Monte Carlo modeling including polar optical phonon-plasmon coupling through a self-consistent dielectric function. Realistic electronic structures are provided by a nonlocal empirical pseudopotential method. It is found that GaAs0.50Sb0.50 does not show a mobility enhancement for very high acceptor doping levels unlike GaAs and Ga0.47In0.53As.

  18. 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

  19. 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

  20. Boron, bismuth co-doping of gallium arsenide and other compounds for photonic and heterojunction bipolar transistor devices

    Science.gov (United States)

    Mascarenhas, Angelo

    2015-07-07

    Isoelectronic co-doping of semiconductor compounds and alloys with acceptors and deep donors is sued to decrease bandgap, to increase concentration of the dopant constituents in the resulting alloys, and to increase carrier mobilities lifetimes. For example, Group III-V compounds and alloys, such as GaAs and GaP, are isoelectronically co-doped with, for example, B and Bi, to customize solar cells, and other semiconductor devices. Isoelectronically co-doped Group II-VI compounds and alloys are also included.

  1. Boron, bismuth co-doping of gallium arsenide and other compounds for photonic and heterojunction bipolar transistor devices

    Energy Technology Data Exchange (ETDEWEB)

    Mascarenhas, Angelo

    2017-08-01

    Isoelectronic co-doping of semiconductor compounds and alloys with acceptors and deep donors is used to decrease bandgap, to increase concentration of the dopant constituents in the resulting alloys, and to increase carrier mobilities lifetimes. For example, Group III-V compounds and alloys, such as GaAs and GaP, are isoelectronically co-doped with, for example, B and Bi, to customize solar cells, and other semiconductor devices. Isoelectronically co-doped Group II-VI compounds and alloys are also included.

  2. 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

  3. 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;}

  4. 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

  5. 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.

  6. 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 ...

  7. 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.

  8. 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

  9. A 6-bit 3-Gsps ADC implemented in 1 μm GaAs HBT technology

    International Nuclear Information System (INIS)

    Zhang Jincan; Zhang Yuming; Lü Hongliang; Zhang Yimen; Xiao Guangxing; Ye Guiping

    2014-01-01

    The design and test results of a 6-bit 3-Gsps analog-to-digital converter (ADC) using 1 μm GaAs heterojunction bipolar transistor (HBT) technology are presented. The monolithic folding-interpolating ADC makes use of a track-and-hold amplifier (THA) with a highly linear input buffer to maintain a highly effective number of bits (ENOB). The ADC occupies an area of 4.32 × 3.66 mm 2 and achieves 5.53 ENOB with an effective resolution bandwidth of 1.1 GHz at a sampling rate of 3 Gsps. The maximum DNL and INL are 0.36 LSB and 0.48 LSB, respectively. (semiconductor integrated circuits)

  10. 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

  11. 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

  12. 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

  13. 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.

  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. 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.

  16. Ion implanted GaAs microwave FET's

    Science.gov (United States)

    Gill, S. S.; Blockley, E. G.; Dawsey, J. R.; Foreman, B. J.; Woodward, J.; Ball, G.; Beard, S. J.; Gaskell, J. M.; Allenson, M. B.

    1988-06-01

    The combination of ion implantation and photolithographic patterning techniques was applied to the fabrication of GaAs microwave FETs to provide a large number of devices having consistently predictable dc and high frequency characteristics. To validate the accuracy and repeatability of the high frequency device parameters, an X-band microwave circuit was designed and realized. The performance of this circuit, a buffered amplifier, is very close to the design specification. The availability of a large number of reproducible, well-characterized transistors enabled work to commence on the development of a large signal model for FETs. Work in this area is also described.

  17. Ultra-Low Power Optical Transistor Using a Single Quantum Dot Embedded in a Photonic Wire

    DEFF Research Database (Denmark)

    Nguyen, H.A.; Grange, T.; Malik, N.S.

    2017-01-01

    Using a single InAs quantum dot embedded in a GaAs photonic wire, we realize a giant non-linearity between two optical modes to experimentally demonstrate an all-optical transistor triggered by 10 photons.......Using a single InAs quantum dot embedded in a GaAs photonic wire, we realize a giant non-linearity between two optical modes to experimentally demonstrate an all-optical transistor triggered by 10 photons....

  18. 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...

  19. 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....

  20. 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)

  1. 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.)

  2. 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)

  3. 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

  4. 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).

  5. 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

  6. 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. ...

  7. 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...

  8. 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 ...

  9. 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.

  10. 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.

  11. Simulation of a Nonlinear GaAs MESFET Model for use in the ...

    African Journals Online (AJOL)

    A computer program has been developed that performs a large-signal simulation of a GaAs Metal-Semiconductor-Field-Effect-Transistor (MESFET) using the Curtice-Ettenberg model [1]. The model is then used to design non-linear microwave circuits such as frequency multipliers and power amplifiers. The simulation ...

  12. Optimization of selective area growth of GaAs by low pressure organometallic vapor phase epitaxy for monolithic integrated circuits

    Science.gov (United States)

    Kanber, H.; Bar, S. X.; Norris, P. E.; Beckham, C.; Pacer, M.

    1994-02-01

    GaAs MESFET device structures have been grown on silicon nitride or silicon dioxide masked 50 and 76 mm GaAs substrates by low pressure organometallic vapor phase epitaxy. Very smooth, featureless morphology and 100 percent selectivity of GaAs islands have been achieved over a range of growth conditions. Optimization of the GaAs p-buffer of the field effect transistor structure has led to improved device performance, including increased breakdown voltage. Device characteristics of the 0.5 μm gate low noise metal semiconductor field-effect transistors fabricated on these islands show good performance and wafer to wafer reproducibility on the second device lot.

  13. Sidewall GaAs tunnel junctions fabricated using molecular layer epitaxy

    Directory of Open Access Journals (Sweden)

    Takeo Ohno and Yutaka Oyama

    2012-01-01

    Full Text Available In this article we review the fundamental properties and applications of sidewall GaAs tunnel junctions. Heavily impurity-doped GaAs epitaxial layers were prepared using molecular layer epitaxy (MLE, in which intermittent injections of precursors in ultrahigh vacuum were applied, and sidewall tunnel junctions were fabricated using a combination of device mesa wet etching of the GaAs MLE layer and low-temperature area-selective regrowth. The fabricated tunnel junctions on the GaAs sidewall with normal mesa orientation showed a record peak current density of 35 000 A cm-2. They can potentially be used as terahertz devices such as a tunnel injection transit time effect diode or an ideal static induction transistor.

  14. 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.

  15. 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.

  16. 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)

  17. 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.

  18. 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

  19. 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.

  20. 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 ...

  1. 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.

  2. Oxidation of the GaAs semiconductor at the Al2O3/GaAs junction.

    Science.gov (United States)

    Tuominen, Marjukka; Yasir, Muhammad; Lång, Jouko; Dahl, Johnny; Kuzmin, Mikhail; Mäkelä, Jaakko; Punkkinen, Marko; Laukkanen, Pekka; Kokko, Kalevi; Schulte, Karina; Punkkinen, Risto; Korpijärvi, Ville-Markus; Polojärvi, Ville; Guina, Mircea

    2015-03-14

    Atomic-scale understanding and processing of the oxidation of III-V compound-semiconductor surfaces are essential for developing materials for various devices (e.g., transistors, solar cells, and light emitting diodes). The oxidation-induced defect-rich phases at the interfaces of oxide/III-V junctions significantly affect the electrical performance of devices. In this study, a method to control the GaAs oxidation and interfacial defect density at the prototypical Al2O3/GaAs junction grown via atomic layer deposition (ALD) is demonstrated. Namely, pre-oxidation of GaAs(100) with an In-induced c(8 × 2) surface reconstruction, leading to a crystalline c(4 × 2)-O interface oxide before ALD of Al2O3, decreases band-gap defect density at the Al2O3/GaAs interface. Concomitantly, X-ray photoelectron spectroscopy (XPS) from these Al2O3/GaAs interfaces shows that the high oxidation state of Ga (Ga2O3 type) decreases, and the corresponding In2O3 type phase forms when employing the c(4 × 2)-O interface layer. Detailed synchrotron-radiation XPS of the counterpart c(4 × 2)-O oxide of InAs(100) has been utilized to elucidate the atomic structure of the useful c(4 × 2)-O interface layer and its oxidation process. The spectral analysis reveals that three different oxygen sites, five oxidation-induced group-III atomic sites with core-level shifts between -0.2 eV and +1.0 eV, and hardly any oxygen-induced changes at the As sites form during the oxidation. These results, discussed within the current atomic model of the c(4 × 2)-O interface, provide insight into the atomic structures of oxide/III-V interfaces and a way to control the semiconductor oxidation.

  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. 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.

  7. 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.

  8. 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.

  9. Principles of transistor circuits introduction to the design of amplifiers, receivers and digital circuits

    CERN Document Server

    Amos, S W

    2013-01-01

    For over thirty years, Stan Amos has provided students and practitioners with a text they could rely on to keep them at the forefront of transistor circuit design. This seminal work has now been presented in a clear new format and completely updated to include the latest equipment such as laser diodes, Trapatt diodes, optocouplers and GaAs transistors, and the most recent line output stages and switch-mode power supplies.Although integrated circuits have widespread application, the role of discrete transistors is undiminished, both as important building blocks which students must understand an

  10. 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 ...

  11. 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....

  12. Toward a very low-power integrated charge preamplifier by using III-V field effect transistors

    International Nuclear Information System (INIS)

    Geronimo, G. de; Longoni, A.

    1998-01-01

    The future high-energy physics experiments, based on the new high-luminosity accelerators, will require a new generation of front-end monolithic electronics characterized, in particular, by high speed and low-power dissipation. In this perspective, the performances of Si and GaAs field effect transistors (FETs) are compared here in conditions of low-power dissipation. The advantages of solutions based on GaAs FETs, in applications requiring fast shaping times, are presented and experimental results are reported. The criteria for the optimum choice of the input transistor dimension and of its bias point are discussed

  13. 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)

  14. 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 ...

  15. n-Type Doping of Vapor–Liquid–Solid Grown GaAs Nanowires

    Directory of Open Access Journals (Sweden)

    Gutsche Christoph

    2011-01-01

    Full Text Available Abstract In this letter, n-type doping of GaAs nanowires grown by metal–organic vapor phase epitaxy in the vapor–liquid–solid growth mode on (111B GaAs substrates is reported. A low growth temperature of 400°C is adjusted in order to exclude shell growth. The impact of doping precursors on the morphology of GaAs nanowires was investigated. Tetraethyl tin as doping precursor enables heavily n-type doped GaAs nanowires in a relatively small process window while no doping effect could be found for ditertiarybutylsilane. Electrical measurements carried out on single nanowires reveal an axially non-uniform doping profile. Within a number of wires from the same run, the donor concentrations ND of GaAs nanowires are found to vary from 7 × 1017 cm-3 to 2 × 1018 cm-3. The n-type conductivity is proven by the transfer characteristics of fabricated nanowire metal–insulator-semiconductor field-effect transistor devices.

  16. GaAs Refractive Index Dependence On Carrier Density and Optimizing Terahertz Devices

    Science.gov (United States)

    Kim, Christopher; Wu, Dong Ho; Graber, Benjamin

    GaAs is used for various applications, including high speed transistors, high-efficiency photovoltaic cells, electro-optics and terahertz (THz) emitters and detectors. To date, information on the refractive index of GaAs is available only over a limited wave spectrum of 0.2-17um, where the refractive index varies from 1.3 to 5.0. As detailed information on the refractive index of GaAs at THz frequencies is not available or inadequate for our effort to develop an improved GaAs-based THz emitter, we experimentally investigated the behavior of the refractive index of GaAs for different charge carrier densities, especially with or without the presence of surface plasma. Using a Time Domain THz Spectrometer, which is capable of measuring THz pulses containing a wave spectrum over 100-3000um with a time accuracy better than 6 femtoseconds, we measured the delay of THz pulses traversing through a GaAs substrate of known thickness while modulating the charge carrier concentration. From the experimental data we estimated the refractive index for THz frequencies to vary from 3.5 to 3.8 for different charge carrier concentrations. We will discuss details of our experiments and implications of our experimental results, especially for our GaAs-based THz devices.

  17. 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.

  18. Performance improvement of junctionless field effect transistors using p-GaAs/AlGaAs heterostructure

    Science.gov (United States)

    Bajelan, F.; Goharrizi, A. Yazdanpanah; Faez, R.; Darvish, G.

    2017-10-01

    The performance analysis of junctionless (JL) gate-all-around (GAA) metal oxide semiconductor field effect transistors (MOSFETs) is investigated using the Non-Equilibrium Green's Function (NEGF) formalism. The main problem of JL transistors is found to be the OFF-state current. In the present work, the OFF-state current of such devices is decreased by choosing channel materials with a large band gap and heavy effective mass. Our simulation results show that the OFF-state current of JL transistors with p-type GaAs is less than that of n-type GaAs. Plus, the heterostructure (HES) channel is proposed in this study for improving the device characteristics of JL-FETs as compared to homostructure (HOS). Therefore, p-type GaAs and GaAs/AlGaAs are used as the channel material for HOS and HES devices, respectively. The simulation is performed for different thicknesses of GaAs and AlGaAs with a fixed diameter of 5 nm for the nanowire. It is shown that the optimum electronic characteristics of HES devices is achieved when the thicknesses of GaAs and AlGaAs layers are chosen to be 0.5 nm and 4 nm, respectively. OFF-state current (IOFF) of 5.32 × 10-16 A, ON-state current (ION) of 6.44 × 10-6 A, ON/OFF current ratio (ION/IOFF) of 1.21 × 1010, subthreshold slope (SS) of 60.8 mV/dec, drain induced barrier lowering (DIBL) of 4.6 mV/V, and threshold voltage (VTH) of 330 mV are obtained for the proposed HES JL-GAA-FET.

  19. Design of a GaAs X-ray imaging sensor with integrated HEMT readout circuitry

    Energy Technology Data Exchange (ETDEWEB)

    Boardman, D

    2002-01-01

    A new monolithic semi-insulating (SI) GaAs sensor design for X-ray imaging applications between 10-100keV has been proposed. Monolithic pixel detectors offer a number of advantages over hybrid bump-bonded detectors, such as high device yield, low costs and are easier to produce large scale arrays. In this thesis, an investigation is made of the use of a SI GaAs wafer as both a detector element and substrate for the epitaxially grown High Electron Mobility Transistors (HEMTs). The design of the HEMT transistors, optimised for this application, were produced with the aid of the Silvaco 'Virtual Wafer Fab' simulation package. It was determined that the device characteristics would consist of a small positive threshold voltage, a low off-state drain current and high transconductance. The final HEMT transistor design, that would be integrated to a pixel detector, had a threshold voltage of 0.17V, an off-state leakage current of {approx}1nA and a transconductance of 7.4mS. A number of test detectors were characterised using an ion beam induced charge technique. Charge collection efficiency maps of the test detectors were produced to determine their quality as a X-ray detection material. From the results, the inhomogeneity of SI GaAs, homogeneity of epitaxial GaAs and granular nature of polycrystalline GaAs, were observed. The best of these detectors was used in conjunction with a commercial field effect transistor to produce a hybrid device. The charge switching nature of the hybrid device was shown and a sensitivity of 0.44pC/{mu}Gy mm{sup 2}, for a detector bias of 60V, was found. The functionality of the hybrid sensor was the same to that proposed for the monolithic sensor. The fabrication of the monolithic sensor, with an integrated HEMT transistor and external capacitor, was achieved. To reach the next stage of producing a monolithic sensor that integrates charge, requires further work in the design and the fabrication process. (author)

  20. Design of a GaAs X-ray imaging sensor with integrated HEMT readout circuitry

    International Nuclear Information System (INIS)

    Boardman, D.

    2002-01-01

    A new monolithic semi-insulating (SI) GaAs sensor design for X-ray imaging applications between 10-100keV has been proposed. Monolithic pixel detectors offer a number of advantages over hybrid bump-bonded detectors, such as high device yield, low costs and are easier to produce large scale arrays. In this thesis, an investigation is made of the use of a SI GaAs wafer as both a detector element and substrate for the epitaxially grown High Electron Mobility Transistors (HEMTs). The design of the HEMT transistors, optimised for this application, were produced with the aid of the Silvaco 'Virtual Wafer Fab' simulation package. It was determined that the device characteristics would consist of a small positive threshold voltage, a low off-state drain current and high transconductance. The final HEMT transistor design, that would be integrated to a pixel detector, had a threshold voltage of 0.17V, an off-state leakage current of ∼1nA and a transconductance of 7.4mS. A number of test detectors were characterised using an ion beam induced charge technique. Charge collection efficiency maps of the test detectors were produced to determine their quality as a X-ray detection material. From the results, the inhomogeneity of SI GaAs, homogeneity of epitaxial GaAs and granular nature of polycrystalline GaAs, were observed. The best of these detectors was used in conjunction with a commercial field effect transistor to produce a hybrid device. The charge switching nature of the hybrid device was shown and a sensitivity of 0.44pC/μGy mm 2 , for a detector bias of 60V, was found. The functionality of the hybrid sensor was the same to that proposed for the monolithic sensor. The fabrication of the monolithic sensor, with an integrated HEMT transistor and external capacitor, was achieved. To reach the next stage of producing a monolithic sensor that integrates charge, requires further work in the design and the fabrication process. (author)

  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. 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.

  4. Towards low-dimensional hole systems in Be-doped GaAs nanowires

    DEFF Research Database (Denmark)

    Ullah, A. R.; Gluschke, J. G.; Jeppesen, Peter Krogstrup

    2017-01-01

    -gates produced using GaAs nanowires with three different Be-doping densities and various AuBe contact processing recipes. We show that contact annealing only brings small improvements for the moderately doped devices under conditions of lower anneal temperature and short anneal time. We only obtain good......GaAs was central to the development of quantum devices but is rarely used for nanowire-based quantum devices with InAs, InSb and SiGe instead taking the leading role. p-type GaAs nanowires offer a path to studying strongly confined 0D and 1D hole systems with strong spin–orbit effects, motivating...... our development of nanowire transistors featuring Be-doped p-type GaAs nanowires, AuBe alloy contacts and patterned local gate electrodes towards making nanowire-based quantum hole devices. We report on nanowire transistors with traditional substrate back-gates and EBL-defined metal/oxide top...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Photoluminescence studies of GaAs grown on InP substrates by molecular beam epitaxy

    Science.gov (United States)

    Huang, D.; Agarwala, S.; Morkoc, H.

    1989-01-01

    GaAs-based field-effect transistor structures have been grown on InP substrates with the InGaAs/GaAs strained-layer superlattices and 1.5 micron GaAs layer as the buffer. The low-temperature (4 K) photoluminescence (PL) from this GaAs buffer has been studied for the first time. Among five observable peaks, the excitonic transition at energy 1.513 eV and the impurity associated recombination at energy 1.483 eV have been identified with the aid of reflection, absorption, and temperature and excitation-intensity dependent PL measurements. The peak at 1.504 eV, most probably due to an exciton bound to a defect, is greatly enhanced compared with that of homoepitaxially grown GaAs. The optical results show that GaAs films of good quality can be grown on InP substrate, which is consistent with device results.

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

    Science.gov (United States)

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

    2018-08-01

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

  11. 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.

  12. 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 ...

  13. 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.

  14. 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).

  15. 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...

  16. Electron transport in nanometer GaAs structure under radiation exposure

    CERN Document Server

    Demarina, N V

    2002-01-01

    One investigates into effect of neutron and proton irradiation on electron transport in nanometer GaAs structures. Mathematical model takes account of radiation defects via introduction of additional mechanisms od scattering of carriers at point defects and disordered regions. To investigate experimentally into volt-ampere and volt-farad characteristics one used a structure based on a field-effect transistor with the Schottky gate and a built-in channel. Calculation results of electron mobility, drift rate of electrons, time of energy relaxation and electron pulse are compared with the experimental data

  17. 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.

  18. 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.

  19. 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

  20. 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)

  1. Biomolecular detection using a metal semiconductor field effect transistor

    Science.gov (United States)

    Estephan, Elias; Saab, Marie-Belle; Buzatu, Petre; Aulombard, Roger; Cuisinier, Frédéric J. G.; Gergely, Csilla; Cloitre, Thierry

    2010-04-01

    In this work, our attention was drawn towards developing affinity-based electrical biosensors, using a MESFET (Metal Semiconductor Field Effect Transistor). Semiconductor (SC) surfaces must be prepared before the incubations with biomolecules. The peptides route was adapted to exceed and bypass the limits revealed by other types of surface modification due to the unwanted unspecific interactions. As these peptides reveal specific recognition of materials, then controlled functionalization can be achieved. Peptides were produced by phage display technology using a library of M13 bacteriophage. After several rounds of bio-panning, the phages presenting affinities for GaAs SC were isolated; the DNA of these specific phages were sequenced, and the peptide with the highest affinity was synthesized and biotinylated. To explore the possibility of electrical detection, the MESFET fabricated with the GaAs SC were used to detect the streptavidin via the biotinylated peptide in the presence of the bovine Serum Albumin. After each surface modification step, the IDS (current between the drain and the source) of the transistor was measured and a decrease in the intensity was detected. Furthermore, fluorescent microscopy was used in order to prove the specificity of this peptide and the specific localisation of biomolecules. In conclusion, the feasibility of producing an electrical biosensor using a MESFET has been demonstrated. Controlled placement, specific localization and detection of biomolecules on a MESFET transistor were achieved without covering the drain and the source. This method of functionalization and detection can be of great utility for biosensing application opening a new way for developing bioFETs (Biomolecular Field-Effect Transistor).

  2. 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. ...

  3. 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

  4. 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.

  5. 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.

  6. 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...

  7. 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.

  8. 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.

  9. In0.69Al0.31As0.41Sb0.59/In0.27Ga0.73Sb double-heterojunction bipolar transistors with InAs0.66Sb0.34 contact layers

    Science.gov (United States)

    2010-09-01

    semi-insu- lating (SI) GaAs substrate; a buffer of 3000 Å GaAs, 12 Å AlSb , 5000 Å Al0.65Ga0.35Sb, and 1 mm of In0.21Ga0.19Al0.60Sb; a 5000 Å n + (Te...Lett., 2005, 41, pp. 1088–1089 3 Deal, W.R., Tsai, R., Lange, M.D., Boos, J.B., Bennett, B.R., and Gutierrez, A.: ‘A W-band InAs/ AlSb low-noise/low

  10. 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)

  11. 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.

  12. 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.

  13. 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…

  14. 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.

  15. 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 ...

  16. 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.

  17. 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 ...

  18. 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.

  19. Single electron transistor in pure silicon

    Science.gov (United States)

    Hu, Binhui

    As promising candidates for spin qubits, semiconductor quantum dots (QDs) have attracted tremendous research efforts. Currently most advanced progress is from GaAs QDs. Compared to GaAs, lateral QDs in 28silicon are expected to have a spin coherence time orders of magnitude longer, because 28Si has zero nuclear spin, and there is no hyperfine interaction between electron spins and nuclear spins. We have developed enhancement mode metal-oxide-semiconductor (MOS) single electron transistors (SETs) using pure silicon wafers with a bi-layer gated configuration. In an MOS-SET, the top gate is used to induce a two-dimensional electron gas (2DEG), just as in an MOS field effect transistor. The side gates deplete the 2DEG into a QD and two point contact channels; one connects the QD to the source reservoir, and the other connects the QD to the drain reservoir. We have systematically investigated the MOS-SETs at 4.2 K, and separately in a dilution refrigerator with a base temperature of 10 mK. The data show that there is an intrinsic QD in each point contact channel due to the local potential fluctuations in these SETs. However, after scaling down the SETs, we have found that the intrinsic QDs can be removed and the electrostatically defined dots dominate the device behavior, but these devices currently only work in the many-electron regime. In order to realize single electron confinement, it is necessary to continue scaling down the device and improving the interface quality. To explore the spin dynamics in silicon, we have investigated a single intrinsic QD by applying a magnetic field perpendicular to the sample surface. The magnetic field dependence of the ground-state and excited-state energy levels of the QD mostly can be explained by the Zeeman effect, with no obvious orbital effect up to 9 T. The two-electron singlet-triplet (ST) transition is first time directly observed in a silicon QD by excitation spectroscopy. In this ST transition, electron-electron Coulomb

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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 ...

  11. [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.

  12. 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.

  13. InGaP HBT Lift-Off for High Efficiency L-band T/R Module Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal addresses the need for the development of higher efficiency power amplifiers at L-band using GaAs HBT (heterojunction bipolar transistors) for pulsed...

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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/ ...

  2. 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.

  3. Nonlinear optical rectification and second and third harmonic generation in GaAs {delta}-FET systems under hydrostatic pressure

    Energy Technology Data Exchange (ETDEWEB)

    Martinez-Orozco, J.C. [Unidad Academica de Fisica, Universidad Autonoma de Zacatecas, 98060 Zacatecas, ZAC (Mexico); Mora-Ramos, M.E. [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Ave. Universidad 1001, CP 62209 Cuernavaca, Morelos (Mexico); Duque, C.A., E-mail: cduque_echeverri@yahoo.es [Instituto de Fisica, Universidad de Antioquia, AA 1226, Medellin (Colombia)

    2012-02-15

    The GaAs n-type delta-doped field effect transistor is proposed as a source for nonlinear optical responses such as second order rectification and second and third harmonic generation. Particular attention is paid to the effect of hydrostatic pressure on these properties, related with the pressure-induced modifications of the energy level spectrum. The description of the one-dimensional potential profile is made including Hartree and exchange and correlation effects via a Thomas-Fermi-based local density approximation. The allowed energy levels are calculated within the effective mass and envelope function approximations by means of an expansion over an orthogonal set of infinite well eigenfunctions. The results for the coefficients of nonlinear optical rectification and second and third harmonic generation are reported for several values of the hydrostatic pressure. - Highlights: Black-Right-Pointing-Pointer GaAs n-type delta-doped field effect transistor. Black-Right-Pointing-Pointer NOR and SHG are enhanced as a result of the pressure. Black-Right-Pointing-Pointer THG is quenched as a result of the pressure. Black-Right-Pointing-Pointer The zero pressure situation is the best scenario for the THG.

  4. 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.

  5. 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...

  6. 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.

  7. An analytic model for gate-all-around silicon nanowire tunneling field effect transistors

    Science.gov (United States)

    Liu, Ying; He, Jin; Chan, Mansun; Du, Cai-Xia; Ye, Yun; Zhao, Wei; Wu, Wen; Deng, Wan-Ling; Wang, Wen-Ping

    2014-09-01

    An analytical model of gate-all-around (GAA) silicon nanowire tunneling field effect transistors (NW-TFETs) is developted based on the surface potential solutions in the channel direction and considering the band to band tunneling (BTBT) efficiency. The three-dimensional Poisson equation is solved to obtain the surface potential distributions in the partition regions along the channel direction for the NW-TFET, and a tunneling current model using Kane's expression is developed. The validity of the developed model is shown by the good agreement between the model predictions and the TCAD simulation results.

  8. 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.

  9. 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

  10. 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.

  11. 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

  12. Low-noise AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor recessed by electron cyclotron resonance plasma etching

    CERN Document Server

    Lee, J H; Lee, C W; Yoon, H S; Park, B S; Park, C S

    1999-01-01

    GaAs pseudomorphic high electron mobility transistor recessed by electron cyclotron resonance (ECR) plasma etching have been investigated. We used a BCl sub 3 /SF sub 6 gas mixture to implement the gate recess process. We obtained a uniformity of the threshold voltage to within 50 mV in 3-inch wafers. The GaAs PHEMTs with a 0.2-mu m gate length recessed by the ECR plasma exhibited a minimum noise figure (NF sub m sub i sub n) as low as 0.26 dB with an associated gain (G sub a) of 13 dB at 12 GHz. At 18 GHz, the NF sub m sub i sub n was 0.47 dB with a Ga of 11.66 dB. These results suggest that the ECR plasma etching process reported here is suitable as a manufacturing process for gate recess of a GaAs PHEMT.

  13. 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.

  14. 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

  15. [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

  16. 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.

  17. Multiband corrections for the semi-classical simulation of interband tunneling in GaAs tunnel junctions

    Science.gov (United States)

    Louarn, K.; Claveau, Y.; Hapiuk, D.; Fontaine, C.; Arnoult, A.; Taliercio, T.; Licitra, C.; Piquemal, F.; Bounouh, A.; Cavassilas, N.; Almuneau, G.

    2017-09-01

    The aim of this study is to investigate the impact of multiband corrections on the current density in GaAs tunnel junctions (TJs) calculated with a refined yet simple semi-classical interband tunneling model (SCITM). The non-parabolicity of the considered bands and the spin-orbit effects are considered by using a recently revisited SCITM available in the literature. The model is confronted to experimental results from a series of molecular beam epitaxy grown GaAs TJs and to numerical results obtained with a full quantum model based on the non-equilibrium Green’s function formalism and a 6-band k.p Hamiltonian. We emphasize the importance of considering the non-parabolicity of the conduction band by two different measurements of the energy-dependent electron effective mass in N-doped GaAs. We also propose an innovative method to compute the non-uniform electric field in the TJ for the SCITM simulations, which is of prime importance for a successful operation of the model. We demonstrate that, when considering the multiband corrections and this new computation of the non-uniform electric field, the SCITM succeeds in predicting the electrical characteristics of GaAs TJs, and are also in agreement with the quantum model. Besides the fundamental study of the tunneling phenomenon in TJs, the main benefit of this SCITM is that it can be easily embedded into drift-diffusion software, which are the most widely-used simulation tools for electronic and opto-electronic devices such as multi-junction solar cells, tunnel field-effect transistors, or vertical-cavity surface-emitting lasers.

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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 ...

  3. 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.

  4. [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.

  5. Panel fabrication utilizing GaAs solar cells

    Science.gov (United States)

    Mardesich, N.

    1984-01-01

    The development of the GaAs solar cells for space applications is described. The activities in the fabrication of GaAs solar panels are outlined. Panels were fabricated while introducing improved quality control, soldering laydown and testing procedures. These panels include LIPS II, San Marco Satellite, and a low concentration panel for Rockwells' evaluation. The panels and their present status are discussed.

  6. Optical pumping of hot phonons in GaAs

    International Nuclear Information System (INIS)

    Collins, C.L.; Yu, P.Y.

    1982-01-01

    Optical pumping of hot LO phonons in GaAs has been studied as a function of the excitation photon frequency. The experimental results are in good agreement with a model calculation which includes both inter- and intra-valley electron-phonon scatterings. The GAMMA-L and GAMMA-X intervalley electron-phonon interactions in GaAs have been estimated

  7. 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.

  8. 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.

  9. Peeled film GaAs solar cell development

    Science.gov (United States)

    Wilt, D. M.; Thomas, R. D.; Bailey, S. G.; Brinker, D. J.; Deangelo, F. L.

    1990-01-01

    Thin-film, single-crystal gallium arsenide (GaAs) solar cells could exhibit a specific power approaching 700 W/kg including coverglass. A simple process has been described whereby epitaxial GaAs layers are peeled from a reusable substrate. This process takes advantage of the extreme selectivity of the etching rate of aluminum arsenide (AlAs) over GaAs in dilute hydrofluoric acid. The feasibility of using the peeled film technique to fabricate high-efficiency, low-mass GaAs solar cells is presently demonstrated. A peeled film GaAs solar cell was successfully produced. The device, although fractured and missing the aluminum gallium arsenide window and antireflective coating, had a Voc of 874 mV and a fill factor of 68 percent under AM0 illumination.

  10. Peeled film GaAs solar cell development

    Science.gov (United States)

    Wilt, D. M.; Thomas, R. D.; Bailey, S. G.; Brinker, D. J.; Deangelo, F. L.

    Thin-film, single-crystal gallium arsenide (GaAs) solar cells could exhibit a specific power approaching 700 W/kg including coverglass. A simple process has been described whereby epitaxial GaAs layers are peeled from a reusable substrate. This process takes advantage of the extreme selectivity of the etching rate of aluminum arsenide (AlAs) over GaAs in dilute hydrofluoric acid. The feasibility of using the peeled film technique to fabricate high-efficiency, low-mass GaAs solar cells is presently demonstrated. A peeled film GaAs solar cell was successfully produced. The device, although fractured and missing the aluminum gallium arsenide window and antireflective coating, had a Voc of 874 mV and a fill factor of 68 percent under AM0 illumination.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. The development of integrated chemical microsensors in GaAs

    Energy Technology Data Exchange (ETDEWEB)

    CASALNUOVO,STEPHEN A.; ASON,GREGORY CHARLES; HELLER,EDWIN J.; HIETALA,VINCENT M.; BACA,ALBERT G.; HIETALA,S.L.

    1999-11-01

    Monolithic, integrated acoustic wave chemical microsensors are being developed on gallium arsenide (GaAs) substrates. With this approach, arrays of microsensors and the high frequency electronic components needed to operate them reside on a single substrate, increasing the range of detectable analytes, reducing overall system size, minimizing systematic errors, and simplifying assembly and packaging. GaAs is employed because it is both piezoelectric, a property required to produce the acoustic wave devices, and a semiconductor with a mature microelectronics fabrication technology. Many aspects of integrated GaAs chemical sensors have been investigated, including: surface acoustic wave (SAW) sensors; monolithic SAW delay line oscillators; GaAs application specific integrated circuits (ASIC) for sensor operation; a hybrid sensor array utilizing these ASICS; and the fully monolithic, integrated SAW array. Details of the design, fabrication, and performance of these devices are discussed. In addition, the ability to produce heteroepitaxial layers of GaAs and aluminum gallium arsenide (AlGaAs) makes possible micromachined membrane sensors with improved sensitivity compared to conventional SAW sensors. Micromachining techniques for fabricating flexural plate wave (FPW) and thickness shear mode (TSM) microsensors on thin GaAs membranes are presented and GaAs FPW delay line and TSM resonator performance is described.

  16. 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....

  17. 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.

  18. Chip yield for FETs fabricated on low-surface-defect GaAs wafers grown by a new MBE system

    Energy Technology Data Exchange (ETDEWEB)

    Kato, S.; Shigeta, J.; Miyata, T.; Kawata, M. (Central Research Laboratory, Hitachi Ltd., Tokyo (Japan)); Tamura, N. (Kasado Works, Hitachi Ltd., Yamachuci (Japan)); Takahashi, K. (Mechanical Research Laboratory, Hitachi Ltd., Ibaraki (Japan))

    1993-06-15

    A very low defect density is achieved with a new MBE system, in which the diameter of the top-heated Ga cell is as big as 60 mm and the distance between the wafer and the cell is optimized at 450 mm by simulation. This system grows GaAs wafers with a defect density of 14.6 cm[sup -2] for defects larger than 0.67 [mu]m[sup 2]. Our chip yield estimation for field effect transistors in the LSIs fabricated on the wafers shows that the grown wafer can integrate 100,000 FETs if each FET gate is 0.3 [mu]m long and 5 [mu]m wide and a chip yield of 42% is assumed

  19. Remote PECVD silicon nitride films with improved electrical properties for GaAs P-HEMT passivation

    CERN Document Server

    Sohn, M K; Kim, K H; Yang, S G; Seo, K S

    1998-01-01

    In order to obtain thin silicon nitride films with excellent electrical and mechanical properties, we employed RPECVD (Remote Plasma Enhanced Chemical Vapor Deposition) process which produces less plasma-induced damage than the conventional PECVD. Through the optical and electrical measurements of the deposited films, we optimized the various RPECVD process parameters. The optimized silicon nitride films showed excellent characteristics such as small etch rate (approx 33 A/min by 7:1 BHF), high breakdown field (>9 MV/cm), and low compressive stress (approx 3.3x10 sup 9 dyne/cm sup 2). We successfully applied thin RPECVD silicon nitride films to the surface passivation of GaAs pseudomorphic high electron mobility transistors (P-HEMTs) with negligible degradations in DC and RF characteristics.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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....

  5. 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.

  6. 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.

  7. SEMICONDUCTOR DEVICES: Structural and electrical characteristics of lanthanum oxide gate dielectric film on GaAs pHEMT technology

    Science.gov (United States)

    Chia-Song, Wu; Hsing-Chung, Liu

    2009-11-01

    This paper investigates the feasibility of using a lanthanum oxide thin film (La2O3) with a high dielectric constant as a gate dielectric on GaAs pHEMTs to reduce gate leakage current and improve the gate to drain breakdown voltage relative to the conventional GaAs pHEMT. An E/D mode pHEMT in a single chip was realized by selecting the appropriate La2O3 thickness. The thin La2O3 film was characterized: its chemical composition and crystalline structure were determined by X-ray photoelectron spectroscopy and X-ray diffraction, respectively. La2O3 exhibited good thermal stability after post-deposition annealing at 200, 400 and 600 °C because of its high binding-energy (835.6 eV). Experimental results clearly demonstrated that the La2O3 thin film was thermally stable. The DC and RF characteristics of Pt/La2O3/Ti/Au gate and conventional Pt/Ti/Au gate pHEMTs were examined. The measurements indicated that the transistor with the Pt/La2O3/Ti/Au gate had a higher breakdown voltage and lower gate leakage current. Accordingly, the La2O3 thin film is a potential high-k material for use as a gate dielectric to improve electrical performance and the thermal effect in high-power applications.

  8. 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

  9. Si3N4/Si/In0.05Ga0.95As/n endash GaAs metal endash insulator endash semiconductor devices

    International Nuclear Information System (INIS)

    Park, D.; Li, D.; Tao, M.; Fan, Z.; Botchkarev, A.E.; Mohammad, S.N.; Morkoc, H.

    1997-01-01

    We report a novel metal endash insulator endash semiconductor (MIS) structure exhibiting a pseudomorphic In 0.05 Ga 0.95 As layer on GaAs with interface state densities in the low 10 11 eV -1 cm -2 . The structure was grown by a combination of molecular beam epitaxy and chemical vapor deposition methods. The hysteresis and frequency dispersion of the MIS capacitor were lower than 100 mV, some of them as low as 30 mV under a field swing of about ±1.3 MV/cm. The 150-Angstrom-thick In 0.05 Ga 0.95 As channel between Si and GaAs is found to bring about a change in the minority carrier recombination behavior of the GaAs channel, in the same way as done by In 0.53 Ga 0.47 As channel MIS structures. Self-aligned gate depletion mode In 0.05 Ga 0.95 As metal endash insulator endash semiconductor field-effect transistors having 3 μm gate lengths exhibited field-effect bulk mobility of 1400 cm 2 /Vs and transconductances of about 170 mS/mm. copyright 1997 American Institute of Physics

  10. Bipolar latch with compensated keep-alive current

    Directory of Open Access Journals (Sweden)

    Dr. Hans Gustat

    2015-03-01

    Full Text Available A permanent current in addition to the main clocked current is sometimes used to increase the maximum clock rate of a bipolar latch. Although it speeds up the activation of a clocked differential stage, it deteriorates the latch function by the additional current in the inactive phase of each differential stage. Thus, a keep-alive current must be kept small with respect to the main clocked current. In this Letter, a compensation technique is shown avoiding the erroneous output of a keep-alive current. It still speeds up the activation of the main transistor pair, but results in a constant symmetric offset without affecting the differential value of the output voltage. In simulations of flip-flops and clocked comparators, this compensated keep-alive current has a much larger effect on the maximum clock rate than the uncompensated keep-alive current used so far.

  11. Preparation of GaAs photocathodes at low temperature

    International Nuclear Information System (INIS)

    Mulhollan, G.; Clendenin, J.; Tang, H.

    1996-10-01

    The preparation of an atomically clean surface is a necessary step in the formation of negative electron affinity (NEA) GaAs. Traditional methods to this end include cleaving, heat cleaning and epitaxial growth. Cleaving has the advantage of yielding a fresh surface after each cleave, but is limited to small areas and is not suitable for specialized structures. Heat cleaning is both simple and highly successful, so it is used as a preparation method in virtually all laboratories employing a NEA source on a regular basis. Due to its high cost and complexity, epitaxial growth of GaAs with subsequent in vacuo transfer is not a practical solution for most end users of GaAs as a NEA electron source. While simple, the heating cleaning process has a number of disadvantages. Here, a variety of cleaning techniques related to preparation of an atomically clean GaAs surface without heating to 600 C are discussed and evaluated

  12. Diffusion of $^{52}$Mn in GaAs

    CERN Multimedia

    2002-01-01

    Following our previous diffusion studies performed with the modified radiotracer technique, we propose to determine the diffusion of Mn in GaAs under intrinsic conditions in a previously un-investigated temperature region. The aim of the presently proposed experiments is twofold. \\begin{itemize} \\item A quantitative study of Mn diffusion in GaAs at low Mn concentrations would be decisive in providing new information on the diffusion mechanism involved. \\item As Ga vacancies are expected to be involved in the Mn diffusion process it can be predicted that also the GaAs material growth technique most likely plays a role. To clarify this assumption diffusion experiments will be conducted for GaAs material grown by two different techniques. \\end{itemize} For such experiments we ask for two runs of 3 shifts (total of 6 shifts) with $^{52}$Mn$^{+}$ ion beam.

  13. Asenapine for bipolar disorder

    Directory of Open Access Journals (Sweden)

    Scheidemantel T

    2015-12-01

    Full Text Available Thomas Scheidemantel,1 Irina Korobkova,2 Soham Rej,3,4 Martha Sajatovic1,2 1University Hospitals Case Medical Center, 2Case Western Reserve University School of Medicine, Cleveland, OH, USA; 3Department of Psychiatry, University of Toronto, Toronto, ON, 4Geri PARTy Research Group, Jewish General Hospital, Montreal, QC, Canada Abstract: Asenapine (Saphris® is an atypical antipsychotic drug which has been approved by the US Food and Drug Administration for the treatment of schizophrenia in adults, as well as the treatment of acute manic or mixed episodes of bipolar I in both adult and pediatric populations. Asenapine is a tetracyclic drug with antidopaminergic and antiserotonergic activity with a unique sublingual route of administration. In this review, we examine and summarize the available literature on the safety, efficacy, and tolerability of asenapine in the treatment of bipolar disorder (BD. Data from randomized, double-blind trials comparing asenapine to placebo or olanzapine in the treatment of acute manic or mixed episodes showed asenapine to be an effective monotherapy treatment in clinical settings; asenapine outperformed placebo and showed noninferior performance to olanzapine based on improvement in the Young Mania Rating Scale scores. There are limited data available on the use of asenapine in the treatment of depressive symptoms of BD, or in the maintenance phase of BD. The available data are inconclusive, suggesting the need for more robust data from prospective trials in these clinical domains. The most commonly reported adverse effect associated with use of asenapine is somnolence. However, the somnolence associated with asenapine use did not cause significant rates of discontinuation. While asenapine was associated with weight gain when compared to placebo, it appeared to be modest when compared to other atypical antipsychotics, and its propensity to cause increases in hemoglobin A1c or serum lipid levels appeared to be

  14. 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

  15. Spin-dependent quasiparticle transport in aluminum single-electron transistors.

    Science.gov (United States)

    Ferguson, A J; Andresen, S E; Brenner, R; Clark, R G

    2006-08-25

    We investigate the effect of Zeeman splitting on quasiparticle transport in normal-superconducting-normal (NSN) aluminum single-electron transistors (SETs). In the above-gap transport, the interplay of Coulomb blockade and Zeeman splitting leads to spin-dependence of the sequential tunneling. This creates regimes where either one or both spin species can tunnel onto or off the island. At lower biases, spin-dependence of the single quasiparticle state is studied, and operation of the device as a bipolar spin filter is suggested.

  16. Analysing organic transistors based on interface approximation

    International Nuclear Information System (INIS)

    Akiyama, Yuto; Mori, Takehiko

    2014-01-01

    Temperature-dependent characteristics of organic transistors are analysed thoroughly using interface approximation. In contrast to amorphous silicon transistors, it is characteristic of organic transistors that the accumulation layer is concentrated on the first monolayer, and it is appropriate to consider interface charge rather than band bending. On the basis of this model, observed characteristics of hexamethylenetetrathiafulvalene (HMTTF) and dibenzotetrathiafulvalene (DBTTF) transistors with various surface treatments are analysed, and the trap distribution is extracted. In turn, starting from a simple exponential distribution, we can reproduce the temperature-dependent transistor characteristics as well as the gate voltage dependence of the activation energy, so we can investigate various aspects of organic transistors self-consistently under the interface approximation. Small deviation from such an ideal transistor operation is discussed assuming the presence of an energetically discrete trap level, which leads to a hump in the transfer characteristics. The contact resistance is estimated by measuring the transfer characteristics up to the linear region

  17. Implantation annealing in GaAs by incoherent light

    International Nuclear Information System (INIS)

    Davies, D.E.; Ryan, T.G.; Soda, K.J.; Comer, J.J.

    1983-01-01

    Implanted GaAs has been successfully activated through concentrating the output of quartz halogen lamps to anneal in times of the order of 1 sec. The resulting layers are not restricted by the reduced mobilities and thermal instabilities of laser annealed GaAs. Better activation can be obtained than with furnace annealing but this generally requires maximum temperatures >= 1050degC. (author)

  18. Indirect bipolar electrodeposition.

    Science.gov (United States)

    Loget, Gabriel; Roche, Jérome; Gianessi, Eugenio; Bouffier, Laurent; Kuhn, Alexander

    2012-12-12

    Based on the principles of bipolar electrochemistry, localized pH gradients are generated at the surface of conducting particles in solution. This allows the toposelective deposition of inorganic and organic polymer layers via a pH-triggered precipitation mechanism. Due to the intrinsic symmetry breaking of the process, the concept can be used to generate in a straightforward way Janus particles, with one section consisting of deposits obtained from non-electroactive precursors. These indirect electrodeposits, such as SiO(2), TiO(2), or electrophoretic paints, can be further used as an immobilization matrix for other species like dyes or nanoparticles, thus opening promising perspectives for the synthesis of a variety of bifunctional objects with a controlled shape.

  19. 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

  20. The four-gate transistor

    Science.gov (United States)

    Mojarradi, M. M.; Cristoveanu, S.; Allibert, F.; France, G.; Blalock, B.; Durfrene, B.

    2002-01-01

    The four-gate transistor or G4-FET combines MOSFET and JFET principles in a single SOI device. Experimental results reveal that each gate can modulate the drain current. Numerical simulations are presented to clarify the mechanisms of operation. The new device shows enhanced functionality, due to the combinatorial action of the four gates, and opens rather revolutionary applications.

  1. A novel nano-structured GaAs solar cell

    Science.gov (United States)

    Liang, Dong; Gu, Anjia; Huo, Yijie; Yan, Jingzhou; Li, Shuang; Garnett, Erik; Pickett, Evan; Kang, Yangsen; Tan, Meiyueh; Cerruto, Antonio Xavier; Zhu, Jia; Hsu, Ching-Mei; Yao, Yan; Riaziat, Majid; Cui, Yi; Harris, James S.

    2011-03-01

    In this presentation, we will demonstrate a novel solar cell with nano-structured dense arrays of single crystal GaAs conformally grown on nanopillar templates with wafer-scale uniformity. The template is prepared via plasma enhanced etching with a monolayer of Si O2 nanospheres as a mask followed by wet chemical etching. The GaAs p-n junction with an AlGaAs passivation window layer is grown via metal-organic chemical vapor deposition (MOCVD). The rectangular shape of the nano single crystal GaAs reveals anisotropic lateral growth rates of GaAs along (011) and (01 1 directions, which can be engineered by tuning the As H3 flow and temperature during growth. Optical absorption measurements show the outstanding light trapping properties of the nano-structured cell, which agree with the simulation results. I-V characteristics show an efficiency of 1.67% for the nano GaAs solar cell, which is 15% higher than its planar control cell with the same thickness of 200nm. The efficiency is the highest among all the large area GaAs nanowire core-shell solar cells reported in literature by 2010.

  2. Modeling suicide in bipolar disorders.

    Science.gov (United States)

    Malhi, Gin S; Outhred, Tim; Das, Pritha; Morris, Grace; Hamilton, Amber; Mannie, Zola

    2018-02-19

    Suicide is a multicausal human behavior, with devastating and immensely distressing consequences. Its prevalence is estimated to be 20-30 times greater in patients with bipolar disorders than in the general population. The burden of suicide and its high prevalence in bipolar disorders make it imperative that our current understanding be improved to facilitate prediction of suicide and its prevention. In this review, we provide a new perspective on the process of suicide in bipolar disorder, in the form of a novel integrated model that is derived from extant knowledge and recent evidence. A literature search of articles on suicide in bipolar disorder was conducted in recognized databases such as Scopus, PubMed, and PsycINFO using the keywords "suicide", "suicide in bipolar disorders", "suicide process", "suicide risk", "neurobiology of suicide" and "suicide models". Bibliographies of identified articles were further scrutinized for papers and book chapters of relevance. Risk factors for suicide in bipolar disorders are well described, and provide a basis for a framework of epigenetic mechanisms, moderated by neurobiological substrates, neurocognitive functioning, and social inferences within the environment. Relevant models and theories include the diathesis-stress model, the bipolar model of suicide and the ideation-to-action models, the interpersonal theory of suicide, the integrated motivational-volitional model, and the three-step theory. Together, these models provide a basis for the generation of an integrated model that illuminates the suicidal process, from ideation to action. Suicide is complex, and it is evident that a multidimensional and integrated approach is required to reduce its prevalence. The proposed model exposes and provides access to components of the suicide process that are potentially measurable and may serve as novel and specific therapeutic targets for interventions in the context of bipolar disorder. Thus, this model is useful not only

  3. A High-Voltage Level Tolerant Transistor Circuit

    NARCIS (Netherlands)

    Annema, Anne J.; Geelen, Godefridus Johannes Gertrudis Maria

    2001-01-01

    A high-voltage level tolerant transistor circuit, comprising a plurality of cascoded transistors, including a first transistor (T1) operatively connected to a high-voltage level node (3) and a second transistor (T2) operatively connected to a low-voltage level node (2). The first transistor (T1)

  4. A radiation hard bipolar monolithic front-end readout

    CERN Document Server

    Baschirotto, A; Cappelluti, I; Castello, R; Cermesoni, M; Gola, A; Pessina, G; Pistolesi, E; Rancoita, P G; Seidman, A

    1999-01-01

    A fast bipolar monolithic charge sensitive preamplifier (CSP), implemented in the monolithic 2 mu m BiCMOS technology (called HF2CMOS) was designed and built in a quad monolithic chip. Studies of radiation effects in the CSP $9 performance, from non-irradiated and up to neutron irradiation of 5.3*10/sup 14/ n/cm/sup 2/, have confirmed that the use of bipolar npn transistors is suitable for the radiation level of the future LHC collider environment. The CSP $9 presents a new circuit solution for obtaining adequate slew rate performances which results in an integral linearity better than 0.8554330n 5 V at 20 ns of shaping time, regardless of the bias current selected for the CSP. This way $9 the bias current of the CSP can be set for optimizing the power dissipation with respect to series and parallel noise, especially useful when the CSP is put in a radiation environment. A prototype test with a novel monolithic 20 ns $9 time constant RC-CR shaper, capable to sum up four inputs has been also realized, featurin...

  5. Magnetotransport Properties of Epitaxial Ge/AlAs Heterostructures Integrated on GaAs and Silicon.

    Science.gov (United States)

    Hudait, Mantu K; Clavel, Michael; Goley, Patrick S; Xie, Yuantao; Heremans, Jean J

    2015-10-14

    The magnetotransport properties of epitaxial Ge/AlAs heterostructures with different growth conditions and substrate architectures have been studied under ±9 T magnetic field and at 390 mK temperature. Systematic mobility measurements of germanium (Ge) epilayers grown on GaAs substrates at growth temperatures from 350 to 450 °C allow us to extract a precise growth window for device-quality Ge, corroborated by structural and morphological properties. Our results on Si substrate using a composite metamorphic AlAs/GaAs buffer at 400 °C Ge growth temperature, show that the Ge/AlAs system can be tailored to have a single carrier transport while keeping the charge solely in the Ge layer. Single carrier transport confined to the Ge layer is demonstrated by the weak-localization quantum correction to the conductivity observed at low magnetic fields and 390 mK temperature. The weak localization effect points to a near-absence of spin-orbit interaction for carriers in the electronically active layer and is used here for the first time to pinpoint Ge as this active layer. Thus, the epitaxial Ge grown on Si using AlAs/GaAs buffer architecture is a promising candidate for next-generation energy-efficient fin field-effect transistor applications.

  6. Hydrodynamic electronic fluid instability in GaAs MESFETs at terahertz frequencies

    Science.gov (United States)

    Li, Kang; Hao, Yue; Jin, Xiaoqi; Lu, Wu

    2018-01-01

    III–V compound semiconductor field effect transistors (FETs) are potential candidates as solid state THz emitters and detectors due to plasma wave instability in these devices. Using a 2D hydrodynamic model, here we present the numerical studies of electron fluid instability in a FET structure. The model is implemented in a GaAs MESFET structure with a gate length of 0.2 µm as a testbed by taking into account the non-equilibrium transport and multi-valley non-parabolicity energy bands. The results show that the electronic density instability in the channel can produce stable periodic oscillations at THz frequencies. Along with stable oscillations, negative differential resistance in output characteristics is observed. The THz emission energy density increases monotonically with the drain bias. The emission frequency of electron density oscillations can be tuned by both gate and drain biases. The results suggest that III–V FETs can be a kind of versatile THz devices with good tunability on both radiative power and emission frequency.

  7. Temperature dependence of stacking faults in catalyst-free GaAs nanopillars.

    Science.gov (United States)

    Shapiro, Joshua N; Lin, Andrew; Ratsch, Christian; Huffaker, D L

    2013-11-29

    Impressive opto-electronic devices and transistors have recently been fabricated from GaAs nanopillars grown by catalyst-free selective-area epitaxy, but this growth technique has always resulted in high densities of stacking faults. A stacking fault occurs when atoms on the growing (111) surface occupy the sites of a hexagonal-close-pack (hcp) lattice instead of the normal face-centered-cubic (fcc) lattice sites. When stacking faults occur consecutively, the crystal structure is locally wurtzite instead of zinc-blende, and the resulting band offsets are known to negatively impact device performance. Here we present experimental and theoretical evidence that indicate stacking fault formation is related to the size of the critical nucleus, which is temperature dependent. The difference in energy between the hcp and fcc orientation of small nuclei is computed using density-function theory. The minimum energy difference of 0.22 eV is calculated for a nucleus with 21 atoms, so the population of nuclei in the hcp orientation is expected to decrease as the nucleus grows larger. The experiment shows that stacking fault occurrence is dramatically reduced from 22% to 3% by raising the growth temperature from 730 to 790 ° C. These data are interpreted using classical nucleation theory which dictates a larger critical nucleus at higher growth temperature.

  8. Quetiapine monotherapy for bipolar depression

    Directory of Open Access Journals (Sweden)

    Michael E Thase

    2008-03-01

    Full Text Available Michael E ThaseDepartments of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, PA, USA; the Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, USA; and the University of Pittsburgh Medical Center, Pittsburgh, PA, USAAbstract: Bipolar depression is more common, disabling, and difficult-to-treat than the manic and hypomanic phases that define bipolar disorder. Unlike the treatment of so-called “unipolar” depressions, antidepressants generally are not indicated as monotherapies for bipolar depressions and recent studies suggest that - even when used in combination with traditional mood stabilizers – antidepressants may have questionable value for bipolar depression. The current practice is that mood stabilizers are initiated first as monotherapies; however, the antidepressant efficacy of lithium and valproate is modest at best. Within this context the role of atypical antipsychotics is being evaluated. The combination of olanzapine and the antidepressant fluoxetine was the first treatment to receive regulatory approval in the US specifically for bipolar I depression. Quetiapine was the second medication to be approved for this indication, largely as the result of two pivotal trials known by the acronyms of BOLDER (BipOLar DEpRession I and II. Both studies demonstrated that two doses of quetiapine (300 mg and 600 mg given once daily at bedtime were significantly more effective than placebo, with no increased risk of patients switching into mania. Pooling the two studies, quetiapine was effective for both bipolar I and bipolar II depressions and for patients with (and without a history of rapid cycling. The two doses were comparably effective in both studies. Although the efficacy of quetiapine monotherapy has been established, much additional research is necessary. Further studies are needed to more fully investigate dose-response relationships and comparing quetiapine monotherapy to other mood stabilizers

  9. The fitting parameters extraction of conversion model of the low dose rate effect in bipolar devices

    International Nuclear Information System (INIS)

    Bakerenkov, Alexander

    2011-01-01

    The Enhanced Low Dose Rate Sensitivity (ELDRS) in bipolar devices consists of in base current degradation of NPN and PNP transistors increase as the dose rate is decreased. As a result of almost 20-year studying, the some physical models of effect are developed, being described in detail. Accelerated test methods, based on these models use in standards. The conversion model of the effect, that allows to describe the inverse S-shaped excess base current dependence versus dose rate, was proposed. This paper presents the problem of conversion model fitting parameters extraction.

  10. Bulk GaAs as a solar neutrino detector

    Energy Technology Data Exchange (ETDEWEB)

    Gavrin, V.N.; Kozlova, Y.P. E-mail: gavrin@adonis.iasnet.ru; Veretenkin, E.P.; Bowles, T.J.; Eremin, V.K.; Verbitskaya, E.M.; Markov, A.V.; Polyakov, A.Y.; Koshelev, O.G.; Morozova, V.F

    2001-06-21

    A GaAs detector may offer the unique possibility to independently study neutrino properties and solar physics. The ability to measure the flux of p-p, {sup 7}Be and pep solar neutrinos would allow one to approach a solution of the 'solar neutrino problem', i.e. the explanation of the significant deficit in observed capture rate of solar neutrinos. A large GaAs solar neutrino detector would allow to measure parameters for possible Mikheyev-Smirnov-Wolfenstein neutrino oscillations with unprecedented precision. A model-independent test for sterile neutrinos is also possible. A direct measurement of the temperature profile of the Sun center appears feasible. A GaAs detector would also provide the ability to observe neutral current interactions in addition to addressing a wide range of other interesting physics. In order to measure the p-p, pep and {sup 7}Be neutrinos a detector is required with low threshold (< 350 keV), good energy resolution (< 2 keV) and low background. A GaAs solid-state detector could meet the listed requirements. A large GaAs detector would be composed of approximately 40,000 intrinsic GaAs crystals, each weighting 3.2 kg. Such a detector would have a mass of 125 ton and would contain 60 ton of Ga occupying a volume of roughly 3 m on one side. Previous efforts by many groups have resulted in producing very small detectors with reasonably good resolution. However, it has thus far proved impossible to make large detectors with good resolution. Thus, a solar neutrino detector such as the one described above is obviously very ambitious, but the scientific motivation is sufficiently high that we have begun a research and development program with the goal of determining the technical feasibility of constructing large GaAs crystals with the requisite electronic properties to serve as particle detectors.

  11. DARPA, SDI, and GaAs

    International Nuclear Information System (INIS)

    Karp, S.; Rooslid, S.

    1986-01-01

    When silicon replaced germanium in the early 1960's as the semiconductor of choice for solid state devices, it converted the entire industry in just a few years because of two important characteristics. First, silicon has a higher energy bandgap, which permits silicon-based devices to operate over a wider temperature range (a feature especially important to the military). Second, and more important, silicon has a native oxide that provided for improved stability and planar, rather than mesa, type devices. Planar technology soon spawned integrated circuits. The integrated circuit in turn brought on the electronics revolution, allowing the complexity of circuits to increase by a factor of two every year (Moore's Law) and bringing us from single transistors to megabit memory chips

  12. Integrated neurobiology of bipolar disorder

    Directory of Open Access Journals (Sweden)

    Vladimir eMaletic

    2014-08-01

    Full Text Available From a neurobiological perspective there is no such thing as bipolar disorder. Rather, it is almost certainly the case that many somewhat similar, but subtly different, pathological conditions produce a disease state that we currently diagnose as bipolarity. This heterogeneity—reflected in the lack of synergy between our current diagnostic schema and our rapidly advancing scientific understanding of the condition—limits attempts to articulate an integrated perspective on bipolar disorder. However, despite these challenges, scientific findings in recent years are beginning to offer a provisional unified field theory of the disease. This theory sees bipolar disorder as a suite of related neurodevelopmental conditions with interconnected functional abnormalities that often appear early in life and worsen over time. In addition to accelerated loss of volume in brain areas known to be essential for mood regulation and cognitive function, consistent findings have emerged at a cellular level, providing evidence that bipolar disorder is reliably associated with dysregulation of glial-neuronal interactions. Among these glial elements are microglia—the brain’s primary immune elements, which appear to be overactive in the context of bipolarity. Multiple studies now indicate that inflammation is also increased in the periphery of the body in both the depressive and manic phases of the illness, with at least some return to normality in the euthymic state. These findings are consistent with changes in the HPA axis, which are known to drive inflammatory activation. In summary, the very fact that no single gene, pathway or brain abnormality is likely to ever account for the condition is itself an extremely important first step in better articulating an integrated perspective on both its ontological status and pathogenesis. Whether this perspective will translate into the discovery of innumerable more homogeneous forms of bipolarity is one of the great

  13. Power transistor module for high current applications

    International Nuclear Information System (INIS)

    Cilyo, F.F.

    1975-01-01

    One of the parts needed for the control system of the 400-GeV accelerator at Fermilab was a power transistor with a safe operating area of 1800A at 50V, dc current gain of 100,000 and 20 kHz bandwidth. Since the commercially available discrete devices and power hybrid packages did not meet these requirements, a power transistor module was developed which performed satisfactorily. By connecting 13 power transistors in parallel, with due consideration for network and heat dissipation problems, and by driving these 13 with another power transistor, a super power transistor is made, having an equivalent current, power, and safe operating area capability of 13 transistors. For higher capabilities, additional modules can be conveniently added. (auth)

  14. 3-D GaAs radiation detectors

    CERN Document Server

    Meikle, A R; Ledingham, Kenneth W D; Marsh, J H; Mathieson, K; O'Shea, V; Smith, K M

    2002-01-01

    A novel type of GaAs radiation detector featuring a 3-D array of electrodes that penetrate through the detector bulk is described. The development of the technology to fabricate such a detector is presented along with electrical and radiation source tests. Simulations of the electrical characteristics are given for detectors of various dimensions. Laser drilling, wet chemical etching and metal evaporation were used to create a cell array of nine electrodes, each with a diameter of 60 mu m and a pitch of 210 mu m. Electrical measurements showed I-V characteristics with low leakage currents and high breakdown voltages. The forward and reverse I-V measurements showed asymmetrical characteristics, which are not seen in planar diodes. Spectra were obtained using alpha particle illumination. A charge collection efficiency of 50% and a S/N ratio of 3 : 1 were obtained. Simulations using the MEDICI software package were performed on cells with various dimensions and were comparable with experimental results. Simulati...

  15. 3-D GaAs radiation detectors

    International Nuclear Information System (INIS)

    Meikle, A.R.; Bates, R.L.; Ledingham, K.; Marsh, J.H.; Mathieson, K.; O'Shea, V.; Smith, K.M.

    2002-01-01

    A novel type of GaAs radiation detector featuring a 3-D array of electrodes that penetrate through the detector bulk is described. The development of the technology to fabricate such a detector is presented along with electrical and radiation source tests. Simulations of the electrical characteristics are given for detectors of various dimensions. Laser drilling, wet chemical etching and metal evaporation were used to create a cell array of nine electrodes, each with a diameter of 60 μm and a pitch of 210 μm. Electrical measurements showed I-V characteristics with low leakage currents and high breakdown voltages. The forward and reverse I-V measurements showed asymmetrical characteristics, which are not seen in planar diodes. Spectra were obtained using alpha particle illumination. A charge collection efficiency of 50% and a S/N ratio of 3 : 1 were obtained. Simulations using the MEDICI software package were performed on cells with various dimensions and were comparable with experimental results. Simulations of a nine-electrode cell with 10 μm electrodes with a 25 μm pitch were also performed. The I-V characteristics again showed a high breakdown voltage with a low leakage current but also showed a full depletion voltage of just 8 V

  16. [Genetics of bipolar disorder].

    Science.gov (United States)

    Budde, M; Forstner, A J; Adorjan, K; Schaupp, S K; Nöthen, M M; Schulze, T G

    2017-07-01

    Bipolar disorder (BD) has a multifactorial etiology. Its development is influenced by genetic as well as environmental factors. Large genome-wide association studies (GWAS), in which genetic risk allelic variants for the disorder could be replicated for the first time, marked the breakthrough in the identification of the responsible risk genes. In addition to these common genetic variants with moderate effects identified by GWAS, rare variants with a higher penetrance are expected to play a role in disease development. The results of recent studies suggest that copy number variants might contribute to BD development, although to a lesser extent than in other psychiatric disorders, such as schizophrenia or autism. Results from the initial next generation sequencing studies indicate an enrichment of rare variants in pathways and genes that were previously found to be associated with BD. In the field of pharmacogenetics, a risk gene that influences the individual variance in the response to lithium treatment was identified for the first time in a recent large international GWAS. Currently the reported risk alleles do not sufficiently explain the phenotypic variance to be used for individual prediction of disease risk, disease course or response to medication. Future genetic research will provide important insights into the biological basis of BD by the identification of additional genes associated with BD. This knowledge of genetics will help identify potential etiological subgroups as well as cross-diagnostic disease mechanisms.

  17. Single-transistor-clocked flip-flop

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Peiyi; Darwish, Tarek; Bayoumi, Magdy

    2005-08-30

    The invention provides a low power, high performance flip-flop. The flip-flop uses only one clocked transistor. The single clocked transistor is shared by the first and second branches of the device. A pulse generator produces a clock pulse to trigger the flip-flop. In one preferred embodiment the device can be made as a static explicit pulsed flip-flop which employs only two clocked transistors.

  18. Fabrication and characterization of novel gate-all-around polycrystalline silicon junctionless field-effect transistors with ultrathin horizontal tube-shape channel

    Science.gov (United States)

    Chang, You-Tai; Peng, Kang-Ping; Li, Pei-Wen; Lin, Horng-Chih

    2018-04-01

    In this paper, we report on a novel fabrication process for the production of junctionless field-effect transistors with an ultrathin polycrystalline silicon (poly-Si) tube channel in a gate-all-around (GAA) configuration. The core of the poly-Si tube channel is filled with either a silicon nitride or a silicon oxide layer, and the effects of the core layers on the device characteristics are evaluated. The devices show excellent switching performance, thanks to the combination of the ultrathin tube channel and the GAA structure. Hysteresis loops in the transfer characteristics of the nitride-core devices are observed, owing to the dynamic trapping of electrons in the nitride core.

  19. Gate-all-around junctionless silicon transistors with atomically thin nanosheet channel (0.65 nm) and record sub-threshold slope (43 mV/dec)

    Science.gov (United States)

    Thirunavukkarasu, Vasanthan; Jhan, Yi-Ruei; Liu, Yan-Bo; Kurniawan, Erry Dwi; Lin, Yu Ru; Yang, Shang-Yi; Cheng, Che-Hsiang; Wu, Yung-Chun

    2017-01-01

    A silicon junctionless (JL) trench gate-all-around (GAA) nanowire field-effect transistor with an atomically thin channel thickness of 0.65 nm and a very thin oxide with a thickness of 12.3 nm are demonstrated experimentally. Experimental results indicate that this device with a channel thickness of 0.65 nm achieves a sub-threshold slope (SS) of 43 mV/decade, which is the best yet achieved by any reported JLFET. Owing to the atomically thin channel, this device has an extremely high ION/IOFF current ratio of >108. Furthermore, the atomically thin channel GAA JLFET exhibits a low threshold voltage (VTH) variation and negligible drain-induced barrier lowering (DIBL tunneling generation rate of 1.2 × 1024/cm2 s when the channel is scaled down to tunneling provides a means of achieving an SS value much lower than its fundamental physical limit.

  20. Bipolar Disorder in Children and Teens

    Science.gov (United States)

    ... I do? Share Bipolar Disorder in Children and Teens Download PDF Download ePub Order a free hardcopy ... Think about death or suicide Can children and teens with bipolar disorder have other problems? Young people ...

  1. Field Effect Transistor in Nanoscale

    Science.gov (United States)

    2017-04-26

    significant alteration in transport behaviour of these molecular junctions. 15. SUBJECT TERMS Theory , Nanoscale, Field Effect Transistor (FET), Devices...Density Functional Theory (DFT), Non-equilibrium Green Function 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT SAR 18. NUMBER OF PAGES     13...Keep in mind the amount of funding you received relative to the amount of effort you put into the report. References: 1. J. R. Heath and M

  2. Exercising control over bipolar disorder.

    Science.gov (United States)

    Malhi, Gin S; Byrow, Yulisha

    2016-11-01

    Following extensive research exercise has emerged as an effective treatment for major depressive disorder, and it is now a recognised therapy alongside other interventions. In contrast, there is a paucity of research examining the therapeutic effects of exercise for those with bipolar disorder. Given that dysfunctional reward processing is central to bipolar disorder, research suggests that exercise can perhaps be framed as a reward-related event that may have the potential to precipitate a manic episode. The behavioural activation system (BAS) is a neurobehavioural system that is associated with responding to reward and provides an appropriate framework to theoretically examine and better understand the effects of exercise treatment on bipolar disorder. This article discusses recent research findings and provides an overview of the extant literature related to the neurobiological underpinnings of BAS and exercise as they relate to bipolar disorder. This is important clinically because depending on mood state in bipolar disorder, we postulate that exercise could be either beneficial or deleterious with positive or negative effects on the illness. Clearly, this complicates the evaluation of exercise as a potential treatment in terms of identifying its optimal characteristics in this population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  3. Electrothermal simulations of high-power SOI vertical DMOS transistors with lateral drain contacts under unclamped inductive switching test

    Science.gov (United States)

    Pinardi, Kuntjoro; Heinle, Ulrich; Bengtsson, Stefan; Olsson, Jörgen; Colinge, Jean-Pierre

    2004-07-01

    Electrothermal effects during the unclamped inductive switching (UIS) of silicon-on-insulator (SOI) high power vertical double diffused MOS (VDMOS) transistors have been studied by device simulation. In the UIS test all the energy stored in the inductor during the on state is dumped directly into the device when the device is turned off. This extreme condition during the UIS test will give ratings for the power device and gives a measure for the stability of the device in the breakdown regime. Electrothermal simulations of this device are evaluated under boundary conditions imposed by the UIS circuit. Simulations show that UIS involves a substantial risk of turning the parasitic bipolar transistor (BJT) on. Our measurements of the fabricated SOI VDMOSFET in the static region are in good agreement with the expected impact of the self-heating on the saturation behaviour. The experiments at ambient temperature of 100 °C show that the breakdown voltage decreases as the drain voltage increases. This indicates that the parasitic BJT has been turned on and causes an open-base bipolar transistor breakdown voltage.

  4. Response of diodes and transistors to a pulsed laser or γ radiation

    International Nuclear Information System (INIS)

    Pinel, Joseph.

    1971-01-01

    The photocurrents generated by a pulsed ionizing radiation in diodes and bipolar transistors were investigated. The ionizing pulses used were of two kinds: first a pulsed γ radiation with a half-height width equals to 4.5x10 -8 s, and a maximum dose rate of 10 10 rad(Si)/s and secondly a light pulse from a Nd doped laser with lambda=1.06μ, suitable for studying Si device with dose rates higher than 10 14 rad(Si)/s. A theoretical analysis of the photocurrents is presented, and the experimental apparatus and dosimetry involved for both irradiation types are described. Results given show that the fast component of the primary photocurrent is a linearly increasing function of the dose rate in the region going from 10 6 up to 10 11 rad(Si)/s. In a bipolar transistor, the variations in the secondary photocurrent with the dose rate shows the same shape as the gain with the collecting current. On the other hand for γ doses higher than 10 8 rad(Si)/s the surface contribution entails a decrease in the secondary photocurrent. The study of the slow component of the primary photocurrent constitutes a direct method of measuring the in-bulk lifetime of a device. The method is usable, whatever may be the value of the injection rate of carriers and the nature of the pulsed radiation (laser, γ, X radiation, or electrons) [fr

  5. Ambipolar nonvolatile memory based on a quantum-dot transistor with a nanoscale floating gate

    International Nuclear Information System (INIS)

    Che, Yongli; Zhang, Yating; Song, Xiaoxian; Cao, Mingxuan; Zhang, Guizhong; Yao, Jianquan; Cao, Xiaolong; Dai, Haitao; Yang, Junbo

    2016-01-01

    Using only solution processing methods, we developed ambipolar quantum-dot (QD) transistor floating-gate memory (FGM) that uses Au nanoparticles as a floating gate. Because of the bipolarity of the active channel of PbSe QDs, the memory could easily trap holes or electrons in the floating gate by programming/erasing (P/E) operations, which could shift the threshold voltage both up and down. As a result, the memory exhibited good programmable memory characteristics: a large memory window (ΔV th  ∼ 15 V) and a long retention time (>10 5  s). The magnitude of ΔV th depended on both P/E voltages and the bias voltage (V DS ): ΔV th was a cubic function to V P/E and linearly depended on V DS . Therefore, this FGM based on a QD transistor is a promising alternative to its inorganic counterparts owing to its advantages of bipolarity, high mobility, low cost, and large-area production.

  6. Ambipolar nonvolatile memory based on a quantum-dot transistor with a nanoscale floating gate

    Energy Technology Data Exchange (ETDEWEB)

    Che, Yongli; Zhang, Yating, E-mail: yating@tju.edu.cn; Song, Xiaoxian; Cao, Mingxuan; Zhang, Guizhong; Yao, Jianquan [Institute of Laser and Opto-Electronics, College of Precision Instruments and Opto-Electronics Engineering, Tianjin University, Tianjin 300072 (China); Key Laboratory of Opto-Electronics Information Technology, Ministry of Education, Tianjin University, Tianjin 300072 (China); Cao, Xiaolong [Institute of Laser and Opto-Electronics, College of Precision Instruments and Opto-Electronics Engineering, Tianjin University, Tianjin 300072 (China); Key Laboratory of Opto-Electronics Information Technology, Ministry of Education, Tianjin University, Tianjin 300072 (China); College of Mechanical and Electronic Engineering, Shandong University of Science and Technology, Qingdao 266590 (China); Dai, Haitao [Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology, School of Science, Tianjin University, Tianjin 300072 (China); Yang, Junbo [Center of Material Science, National University of Defense Technology, Changsha 410073 (China)

    2016-07-04

    Using only solution processing methods, we developed ambipolar quantum-dot (QD) transistor floating-gate memory (FGM) that uses Au nanoparticles as a floating gate. Because of the bipolarity of the active channel of PbSe QDs, the memory could easily trap holes or electrons in the floating gate by programming/erasing (P/E) operations, which could shift the threshold voltage both up and down. As a result, the memory exhibited good programmable memory characteristics: a large memory window (ΔV{sub th} ∼ 15 V) and a long retention time (>10{sup 5 }s). The magnitude of ΔV{sub th} depended on both P/E voltages and the bias voltage (V{sub DS}): ΔV{sub th} was a cubic function to V{sub P/E} and linearly depended on V{sub DS}. Therefore, this FGM based on a QD transistor is a promising alternative to its inorganic counterparts owing to its advantages of bipolarity, high mobility, low cost, and large-area production.

  7. Imunologia do transtorno bipolar Immunology of bipolar disorder

    Directory of Open Access Journals (Sweden)

    Izabela Guimarães Barbosa

    2009-01-01

    Full Text Available OBJETIVO: Pesquisas recentes têm implicado fatores imunes na patogênese de diversos transtornos neuropsiquiátricos. O objetivo do presente trabalho é revisar os trabalhos que investigaram a associação entre transtorno bipolar e alterações em parâmetros imunes. MÉTODOS: Artigos que incluíam as palavras-chave: "bipolar disorder", "mania", "immunology", "cytokines", "chemokines", "interleukins", "interferon" e "tumor necrosis factor" foram selecionados em uma revisão sistemática da literatura. As bases de dados avaliadas foram MedLine e Scopus, entre os anos de 1980 e 2008. RESULTADOS: Foram identificados 28 trabalhos que estudaram alterações imunes em pacientes com transtorno bipolar. Seis artigos investigaram genes relacionados à resposta imune; cinco, autoanticorpos; quatro, populações leucocitárias; 13, citocinas e/ou moléculas relacionadas à resposta imune e seis, leucócitos de pacientes in vitro. CONCLUSÕES: Embora haja evidências na literatura correlacionando o transtorno bipolar a alterações imunes, os dados não são conclusivos. O transtorno bipolar parece estar associado a níveis mais elevados de autoanticorpos circulantes, assim como à tendência à ativação imune com produção de citocinas pró-inflamatórias e redução de parâmetros anti-inflamatórios.OBJECTIVE: Emerging research has implicated immune factors in the pathogenesis of a variety of neuropsychiatric disorders. The objective of the present paper is to review the studies that investigated the association between bipolar disorder and immune parameters. METHODS: Papers that included the keywords "bipolar to disorder", "mania", "immunology", "cytokines", "chemokines", "interleukins", "interferon" and "tumor necrosis factor" were selected in a systematic review of the literature. The evaluated databases were MedLine and Scopus in the period between 1980 and 2008. RESULTS: Twenty eight works were found. Six studies investigated immune response

  8. Mathematical models of bipolar disorder

    Science.gov (United States)

    Daugherty, Darryl; Roque-Urrea, Tairi; Urrea-Roque, John; Troyer, Jessica; Wirkus, Stephen; Porter, Mason A.

    2009-07-01

    We use limit cycle oscillators to model bipolar II disorder, which is characterized by alternating hypomanic and depressive episodes and afflicts about 1% of the United States adult population. We consider two non-linear oscillator models of a single bipolar patient. In both frameworks, we begin with an untreated individual and examine the mathematical effects and resulting biological consequences of treatment. We also briefly consider the dynamics of interacting bipolar II individuals using weakly-coupled, weakly-damped harmonic oscillators. We discuss how the proposed models can be used as a framework for refined models that incorporate additional biological data. We conclude with a discussion of possible generalizations of our work, as there are several biologically-motivated extensions that can be readily incorporated into the series of models presented here.

  9. 46 CFR Sec. 7 - Operation under current GAA/MSTS Southeast Asia Program.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Operation under current GAA/MSTS Southeast Asia Program... AUTHORITY VOYAGE DATA Sec. 7 Operation under current GAA/MSTS Southeast Asia Program. In order to adapt the provisions of NSA Order 35 (OPR-2) to the particular circumstances of the present GAA/MSTS Southeast Asia...

  10. Effects of guanidinoacetic acid(gaa supplementation in rats with chronic renal failure(crf

    Directory of Open Access Journals (Sweden)

    Yoshiharu Tsubakihara

    2012-06-01

    *; p<0.05 vs Sham $; p<0.05 vs GAA 0In conclusion, we demonstrated a deficiency of GAA and CRT, and muscle weekness in CRF rats. However, oral GAA supplementation could recover muscle content of CRT and muscle capabilities in these rats.

  11. Atomic hydrogen cleaning of GaAs photocathodes

    International Nuclear Information System (INIS)

    Poelker, M.; Price, J.; Sinclair, C.

    1997-01-01

    It is well known that surface contaminants on semiconductors can be removed when samples are exposed to atomic hydrogen. Atomic H reacts with oxides and carbides on the surface, forming compounds that are liberated and subsequently pumped away. Experiments at Jefferson lab with bulk GaAs in a low-voltage ultra-high vacuum H cleaning chamber have resulted in the production of photocathodes with high photoelectron yield (i.e., quantum efficiency) and long lifetime. A small, portable H cleaning apparatus also has been constructed to successfully clean GaAs samples that are later removed from the vacuum apparatus, transported through air and installed in a high-voltage laser-driven spin-polarized electron source. These results indicate that this method is a versatile and robust alternative to conventional wet chemical etching procedures usually employed to clean bulk GaAs

  12. Intrinsic spin lifetimes in GaAs (110) quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Georg; Roemer, Michael; Huebner, Jens; Oestreich, Michael [Institut fuer Festkoerperphysik, Gottfried Wilhelm Leibniz Universitaet Hannover, Hannover (Germany); Schuh, Dieter; Wegscheider, Werner [Institut fuer Experimentelle und Angewandte Physik, Universitaet Regensburg (Germany)

    2009-07-01

    GaAs(110) quantum wells attract great attention due to the long spin lifetime for electron spins along the growth axis and are, therefore, of interest for future spin based optoelectronic devices. At low temperatures, optical injection of a finite spin polarization yields strongly enhanced spin dephasing due to the Bir Aronov Pikus mechanism that arises from the exchange interaction between electrons and holes. Thus, the intrinsic spin lifetime in GaAs(110) quantum wells has been unknown. In this work, the non-demolition technique of spin noise spectroscopy, which only relies on statistical spin fluctuations, is applied to GaAs(110) quantum wells in order to measure the intrinsic spin lifetimes. Furthermore, the Brownian motion of the electrons modifies the linewidth of the measured spin noise spectra due to time of flight broadening. This effect uniquely allows to study electronic motion at thermal equilibrium.

  13. GaAs strip detectors: the Australian production program

    International Nuclear Information System (INIS)

    Butcher, K.S.A.; Alexiev, D.

    1995-01-01

    The Australian High Energy Physics consortium (composed of the University of Melbourne, the University of Sydney and ANSTO) has been investigating the possibility of producing a large area wheel of SI GaAs detectors for the ATLAS detector array. To help assess the extent of Australia's role in this venture a few SI GaAs microstrip detectors are to be manufactured under contract by the CSIRO division of Radiophysics GaAs IC Prototyping Facility. The planned production of the devices is discussed. First, the reasons for producing the detectors here in Australia are examined, then some basic characteristics of the material are considered, and finally details are provided of the design used for the manufacture of the devices. Two sets of detectors will be produced using the standard Glasgow production recipe; SIGaAs and GaN. The Glasgow mask set is being used as a benchmark against which to compare the Australian devices

  14. Status of fully integrated GaAs particle detectors

    International Nuclear Information System (INIS)

    Braunschweig, W.; Breibach, J.; Kubicki, Th.; Luebelsmeyer, K.; Maesing, Th.; Rente, C.; Roeper, Ch.; Siemes, A.

    1999-01-01

    GaAs strip detectors are of interest because of their radiation hardness at room temperature and the high absorption coefficient of GaAs for x-rays. The detectors currently under development will be used in the VLQ-experiment at the H1 experiment at the HERA collider. This will be the first high energy physics experiment where GaAs detectors will be used. The detectors have a sensitive area of 5 x 4 cm with a pitch of 62 μ m. Due to the high density of channels the biasing resistors and coupling capacitors are integrated. For the resistors a resistive layer made of Cermet is used. The properties of the first fully integrated strip detector are presented

  15. Transcultural aspects of bipolar disorder

    OpenAIRE

    Sanches, Marsal; Jorge, Miguel Roberto

    2004-01-01

    Considerando-se que existem diferenças importantes na maneira como as emoções são vivenciadas e expressas em diferentes culturas, a apresentação e o manejo do transtorno afetivo bipolar sofrem influência de fatores culturais. O presente artigo realiza uma breve revisão da evidência referente aos aspectos transculturais do transtorno bipolar.Cultural variations in the expression of emotions have been described. Consequently, there are cross-cultural influences on the diagnosis and management o...

  16. Peeled film GaAs solar cells for space power

    Science.gov (United States)

    Wilt, D. M.; Deangelo, F. L.; Thomas, R. D.; Bailey, S. G.; Landis, G. A.; Brinker, D. J.; Fatemi, N. S.

    1990-01-01

    Gallium arsenide (GaAs) peeled film solar cells were fabricated, by Organo-Metallic Vapor Phase Epitaxy (OMVPE), incorporating an aluminum arsenide (AlAs) parting layer between the device structure and the GaAs substrate. This layer was selectively removed by etching in dilute hydrofloric (HF) acid to release the epitaxial film. Test devices exhibit high series resistance due to insufficient back contact area. A new design is presented which uses a coverglass superstrate for structural support and incorporates a coplanar back contact design. Devices based on this design should have a specific power approaching 700 W/Kg.

  17. Scanning microwave microscopy applied to semiconducting GaAs structures

    Science.gov (United States)

    Buchter, Arne; Hoffmann, Johannes; Delvallée, Alexandra; Brinciotti, Enrico; Hapiuk, Dimitri; Licitra, Christophe; Louarn, Kevin; Arnoult, Alexandre; Almuneau, Guilhem; Piquemal, François; Zeier, Markus; Kienberger, Ferry

    2018-02-01

    A calibration algorithm based on one-port vector network analyzer (VNA) calibration for scanning microwave microscopes (SMMs) is presented and used to extract quantitative carrier densities from a semiconducting n-doped GaAs multilayer sample. This robust and versatile algorithm is instrument and frequency independent, as we demonstrate by analyzing experimental data from two different, cantilever- and tuning fork-based, microscope setups operating in a wide frequency range up to 27.5 GHz. To benchmark the SMM results, comparison with secondary ion mass spectrometry is undertaken. Furthermore, we show SMM data on a GaAs p-n junction distinguishing p- and n-doped layers.

  18. Peeled film GaAs solar cells for space power

    Science.gov (United States)

    Wilt, D. M.; Deangelo, F. L.; Thomas, R. D.; Bailey, S. G.; Landis, G. A.; Brinker, D. J.; Fatemi, N. S.

    1990-05-01

    Gallium arsenide (GaAs) peeled film solar cells were fabricated, by Organo-Metallic Vapor Phase Epitaxy (OMVPE), incorporating an aluminum arsenide (AlAs) parting layer between the device structure and the GaAs substrate. This layer was selectively removed by etching in dilute hydrofloric (HF) acid to release the epitaxial film. Test devices exhibit high series resistance due to insufficient back contact area. A new design is presented which uses a coverglass superstrate for structural support and incorporates a coplanar back contact design. Devices based on this design should have a specific power approaching 700 W/Kg.

  19. Performance of a GaAs electron source

    International Nuclear Information System (INIS)

    Calabrese, R.; Ciullo, G.; Della Mea, G.; Egeni, G.P.; Guidi, V.; Lamanna, G.; Lenisa, P.; Maciga, B.; Rigato, V.; Rudello, V.; Tecchio, L.; Yang, B.; Zandolin, S.

    1994-01-01

    We discuss the performance improvement of a GaAs electron source. High quantum yield (14%) and constant current extraction (1 mA for more than four weeks) are achieved after a little initial decay. These parameters meet the requirements for application of the GaAs photocathode as a source for electron cooling devices. We also present the preliminary results of a surface analysis experiment, carried out by means of the RBS technique to check the hypothesis of cesium evaporation from the surface when the photocathode is in operation. (orig.)

  20. Electronic monitoring in bipolar disorder.

    Science.gov (United States)

    Faurholt-Jepsen, Maria

    2018-03-01

    Major reasons for the insufficient effects of current treatment options in bipolar disorder include delayed intervention for prodromal depressive and manic symptoms and decreased adherence to psychopharmacological treatment. The reliance on subjective information and clinical evaluations when diagnosing and assessing the severity of depressive and manic symptoms calls for less biased and more objective markers. By using electronic devices, fine-grained data on complex psychopathological aspects of bipolar disorder can be evaluated unobtrusively over the long term. Moreover, electronic data could possibly represent candidate markers of diagnosis and illness activity in bipolar disorder and allow for early and individualized intervention for prodromal symptoms outside clinical settings. 
The present dissertation concerns the use of electronic monitoring as a marker and treatment intervention in bipolar disorder and investigated the scientific literature and body of evidence within the area, which includes ten original study reports and two systematic reviews, one of which included a meta-analysis, conducted by the author of the dissertation. 
Taken together, the literature presented in this dissertation illustrates that 1) smartphone-based electronic self-monitoring of mood seems to reflect clinically assessed depressive and manic symptoms and enables the long-term characterization of mood

instability in bipolar disorder; 2) preliminary results suggest that smartphone-based automatically generated data (e.g. the number of text messages sent/day; the number of incoming and outgoing calls/day; the number of changes in cell tower IDs/day; and voice features) seem to reflect clinically assessed depressive and manic symptoms in bipolar disorder; 3) smartphone-based electronic self-monitoring had no effects on the severity of depressive and manic symptoms in bipolar disorder, according to a randomized controlled trial; and 4) electronic monitoring of psychomotor

  1. Epidemiologia do transtorno bipolar Epidemiology of bipolar disorders

    Directory of Open Access Journals (Sweden)

    Maurício Silva de Lima

    2005-01-01

    Full Text Available A formulação de políticas em saúde mental depende essencialmente de informações a respeito da freqüência e distribuição dos transtornos mentais. Nas últimas duas décadas, pesquisas de base populacional em epidemiologia psiquiátrica têm sido conduzidas, gerando informações detalhadas sobre freqüência, fatores de risco, incapacidade social e utilização de serviços de saúde. Neste artigo, dados sobre a epidemiologia do transtorno bipolar (TB são discutidos, a partir de resultados de recentes pesquisas populacionais: o estudo da Área de Captação Epidemiológica do Instituto Nacional de Saúde Mental dos Estados Unidos (ECA-NIMH, a Pesquisa Nacional de Comorbidade (NCS, a Pesquisa de Morbidade Psiquiátrica na Grã-Bretanha (OPCS, o Estudo Brasileiro Multicêntrico de Morbidade Psiquiátrica e os estudos longitudinais conduzidos por Angst, em Zurique. As estimativas de prevalências de transtorno bipolar são relativamente baixas, independentemente do lugar onde a pesquisa foi conduzida, do tipo de instrumento diagnóstico usado e dos períodos de tempo para os quais a prevalência se aplica. A partir da introdução do conceito de espectro bipolar, ampliando as fronteiras diagnósticas do TB, as estimativas de prevalências encontradas são substancialmente mais altas. Tais estimativas, entretanto, ainda carecem de validação em estudos populacionais. O transtorno afetivo bipolar é igualmente prevalente entre homens e mulheres, sendo mais freqüente entre solteiros ou separados. Indivíduos acometidos têm maiores taxas de desemprego e estão mais sujeitos a utilizarem serviços médicos e serem hospitalizados. O custo e a eficácia dos tratamentos do TB devem ser balanceados com o alto custo individual e social associados à enfermidade.Information about the epidemiology of bipolar disorders is essential for providing a framework for the formulation of effective mental health policy. In the last two decades, population

  2. Memristive device based on a depletion-type SONOS field effect transistor

    Science.gov (United States)

    Himmel, N.; Ziegler, M.; Mähne, H.; Thiem, S.; Winterfeld, H.; Kohlstedt, H.

    2017-06-01

    State-of-the-art SONOS (silicon-oxide-nitride-oxide-polysilicon) field effect transistors were operated in a memristive switching mode. The circuit design is a variation of the MemFlash concept and the particular properties of depletion type SONOS-transistors were taken into account. The transistor was externally wired with a resistively shunted pn-diode. Experimental current-voltage curves show analog bipolar switching characteristics within a bias voltage range of ±10 V, exhibiting a pronounced asymmetric hysteresis loop. The experimental data are confirmed by SPICE simulations. The underlying memristive mechanism is purely electronic, which eliminates an initial forming step of the as-fabricated cells. This fact, together with reasonable design flexibility, in particular to adjust the maximum R ON/R OFF ratio, makes these cells attractive for neuromorphic applications. The relative large set and reset voltage around ±10 V might be decreased by using thinner gate-oxides. The all-electric operation principle, in combination with an established silicon manufacturing process of SONOS devices at the Semiconductor Foundry X-FAB, promise reliable operation, low parameter spread and high integration density.

  3. Aplikasi Perhitungan Pembiasan DC Pada Transistor Dwi Kutub NPN Dengan Visual Basic 6.0

    Directory of Open Access Journals (Sweden)

    Arief Hendra Saptadi

    2010-05-01

    Full Text Available Transistor dwi kutub (Bipolar Junction Transistor adalah salah satu komponen semikonduktor yang sering digunakan dalam rangkaian penguat (amplifier. Untuk menjaga agar komponen ini dapat bekerja di dalam titik operasinya (operating point, maka diperlukan rangkaian pembiasan dengan pengaturan tertentu, yaitu Bias Basis, Bias Bagi Tegangan, Bias Kolektor dan Bias Emitter. Perancangan rangkaian tersebut lazimnya menggunakan perhitungan manual sesuai teori dengan bantuan alat hitung (kalkulator. Proses perancangan ini membutuhkan waktu yang relatif lama dan sangat rentan terjadi kesalahan prosedur perhitungan. Tujuan dari penelitian ini adalah merancang perangkat lunak perhitungan rangkaian pembiasan transistor dwi kutub dengan Visual Basic 6. Proses perancangan meliputi pembuatan form, pembuatan basis data (database, penulisan kode sumber (coding, desain laporan (report dan kompilasi. Dari hasil uji coba diketahui bahwa tingkat kesalahan (error untuk perhitungan seluruh parameter dari 4 jenis rangkaian pembiasan adalah 1,18%, sehingga disimpulkan layak digunakan. Hasil perhitungan juga dapat disajikan secara visual dalam rangkaian. Ditinjau dari sifat perangkat lunak ini sebagai aplikasi komputer, maka terdapat kelemahan dari sisi kepraktisan penggunaan, meski proses perhitungan dapat dilakukan relatif cepat. Selain itu, aplikasi ini masih memerlukan perbaikan dalam menu bantuan (help menu, penggunaan satuan dan faktor pengali.

  4. 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

  5. Ultrasmall transistor-based light sources

    DEFF Research Database (Denmark)

    With Jensen, Per Baunegaard; Tavares, Luciana; Kjelstrup-Hansen, Jakob

    Dette projekt fokuserer på at udvikle transistor baserede nanofiber lyskilder med det overordnede mål at udvikle effektive og nano skalerede flerfarvede lyskilder integreret on-chip.......Dette projekt fokuserer på at udvikle transistor baserede nanofiber lyskilder med det overordnede mål at udvikle effektive og nano skalerede flerfarvede lyskilder integreret on-chip....

  6. Operation and modeling of the MOS transistor

    CERN Document Server

    Tsividis, Yannis

    2011-01-01

    Operation and Modeling of the MOS Transistor has become a standard in academia and industry. Extensively revised and updated, the third edition of this highly acclaimed text provides a thorough treatment of the MOS transistor - the key element of modern microelectronic chips.

  7. Ferroelectric transistor memory arrays on flexible foils

    NARCIS (Netherlands)

    Breemen, A. van; Kam, B.; Cobb, B.; Rodriguez, F.G.; Heck, G. van; Myny, K.; Marrani, A.; Vinciguerra, V.; Gelinck, G.H.

    2013-01-01

    In this paper, we successfully fabricated and operated passive matrix P(VDF-TrFE) transistor arrays, i.e. memory arrays in which no pass-transistors or other additional electronic components are used. Because of the smaller cell, a higher integration density is possible. We demonstrate arrays up to

  8. The spinvalve transistor: technologies and progress

    NARCIS (Netherlands)

    Lodder, J.C.; Monsma, D.J.; Vlutters, R.; Shimatsu, T.; Shimatsu, T.

    1999-01-01

    The paper describes the necessary technologies needed for realising a RT operating spin-valve transistor (SVT) which is in fact a magnetic controlled metal base transistor. The preparation of a 350×350 μm2 SVT consisting of an Si emitter and collector and Co/Cu/Co GMR multilayer are described. The

  9. Floating-Emitter Solar-Cell Transistor

    Science.gov (United States)

    Sah, C. T.; Cheng, L. J.

    1986-01-01

    Conceptual transistor embedded in photovoltaic diode promises to increase efficiency to more than 20 percent. Solar-cell transistor has front-surface contact, rear contact, and floating emitter. Variety of other contact and junction configurations possible, but do not offer ease of fabrication in combination with high performance.

  10. Radiation effects in pigtailed GaAs and GaA1As LEDs

    International Nuclear Information System (INIS)

    Barnes, C.E.

    1981-06-01

    Permanent and transient radiation effects have been studied in Plessey pigtailed, high radiance GaAs and GaAlAs LEDs using neutron, gamma ray and X-ray sources. The radiation-induced source of degradation in these devices was determined by also examining both bare, unpigtailed LEDs and separate samples of the Corning fibers used as pigtails. No transient effects were observed in the unpigtailed LEDs during either pulsed neutron or X-ray exposure. In contrast, the Corning doped silica fibers exhibited strong transient attenuation following pulsed X-ray bombardment. Permanent neutron damage in these pigtailed LEDs consisted essentially of light output degradation in the LED itself. Permanent gamma ray effects due to a Co-60 irradiation of 1 megarad were restricted to a small increase in attenuation in the fiber. The two primary radiation effects were then transient attenuation in the fiber pigtail and permanent neutron-induced degradation of the LED

  11. Universal power transistor base drive control unit

    Science.gov (United States)

    Gale, Allan R.; Gritter, David J.

    1988-01-01

    A saturation condition regulator system for a power transistor which achieves the regulation objectives of a Baker clamp but without dumping excess base drive current into the transistor output circuit. The base drive current of the transistor is sensed and used through an active feedback circuit to produce an error signal which modulates the base drive current through a linearly operating FET. The collector base voltage of the power transistor is independently monitored to develop a second error signal which is also used to regulate base drive current. The current-sensitive circuit operates as a limiter. In addition, a fail-safe timing circuit is disclosed which automatically resets to a turn OFF condition in the event the transistor does not turn ON within a predetermined time after the input signal transition.

  12. Gallium arsenide (GaAs) island growth under SiO(2) nanodisks patterned on GaAs substrates.

    Science.gov (United States)

    Tjahjana, Liliana; Wang, Benzhong; Tanoto, Hendrix; Chua, Soo-Jin; Yoon, Soon Fatt

    2010-05-14

    We report a growth phenomenon where uniform gallium arsenide (GaAs) islands were found to grow underneath an ordered array of SiO(2) nanodisks on a GaAs(100) substrate. Each island eventually grows into a pyramidal shape resulting in the toppling of the supported SiO(2) nanodisk. This phenomenon occurred consistently for each nanodisk across a large patterned area of approximately 50 x 50 microm(2) (with nanodisks of 210 nm diameter and 280 nm spacing). The growth mechanism is attributed to a combination of 'catalytic' growth and facet formation.

  13. Mixed features in bipolar disorder.

    Science.gov (United States)

    Solé, Eva; Garriga, Marina; Valentí, Marc; Vieta, Eduard

    2017-04-01

    Mixed affective states, defined as the coexistence of depressive and manic symptoms, are complex presentations of manic-depressive illness that represent a challenge for clinicians at the levels of diagnosis, classification, and pharmacological treatment. The evidence shows that patients with bipolar disorder who have manic/hypomanic or depressive episodes with mixed features tend to have a more severe form of bipolar disorder along with a worse course of illness and higher rates of comorbid conditions than those with non-mixed presentations. In the updated Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5), the definition of "mixed episode" has been removed, and subthreshold nonoverlapping symptoms of the opposite pole are captured using a "with mixed features" specifier applied to manic, hypomanic, and major depressive episodes. However, the list of symptoms proposed in the DSM-5 specifier has been widely criticized, because it includes typical manic symptoms (such as elevated mood and grandiosity) that are rare among patients with mixed depression, while excluding symptoms (such as irritability, psychomotor agitation, and distractibility) that are frequently reported in these patients. With the new classification, mixed depressive episodes are three times more common in bipolar II compared with unipolar depression, which partly contributes to the increased risk of suicide observed in bipolar depression compared to unipolar depression. Therefore, a specific diagnostic category would imply an increased diagnostic sensitivity, would help to foster early identification of symptoms and ensure specific treatment, as well as play a role in suicide prevention in this population.

  14. Integrated Neurobiology of Bipolar Disorder

    Science.gov (United States)

    Maletic, Vladimir; Raison, Charles

    2014-01-01

    From a neurobiological perspective there is no such thing as bipolar disorder. Rather, it is almost certainly the case that many somewhat similar, but subtly different, pathological conditions produce a disease state that we currently diagnose as bipolarity. This heterogeneity – reflected in the lack of synergy between our current diagnostic schema and our rapidly advancing scientific understanding of the condition – limits attempts to articulate an integrated perspective on bipolar disorder. However, despite these challenges, scientific findings in recent years are beginning to offer a provisional “unified field theory” of the disease. This theory sees bipolar disorder as a suite of related neurodevelopmental conditions with interconnected functional abnormalities that often appear early in life and worsen over time. In addition to accelerated loss of volume in brain areas known to be essential for mood regulation and cognitive function, consistent findings have emerged at a cellular level, providing evidence that bipolar disorder is reliably associated with dysregulation of glial–neuronal interactions. Among these glial elements are microglia – the brain’s primary immune elements, which appear to be overactive in the context of bipolarity. Multiple studies now indicate that inflammation is also increased in the periphery of the body in both the depressive and manic phases of the illness, with at least some return to normality in the euthymic state. These findings are consistent with changes in the hypothalamic–pituitary–adrenal axis, which are known to drive inflammatory activation. In summary, the very fact that no single gene, pathway, or brain abnormality is likely to ever account for the condition is itself an extremely important first step in better articulating an integrated perspective on both its ontological status and pathogenesis. Whether this perspective will translate into the discovery of innumerable more homogeneous forms of

  15. Effect of proton and electron-irradiation intensity on radiation-induced damages in silicon bioolar transistors

    International Nuclear Information System (INIS)

    Bannikov, Yu.A.; Gorin, B.M.; Kozhevnikov, V.P.; Mikhnovich, V.V.; Gusev, L.I.

    1981-01-01

    The increase of radiation-induced damages of bipolar n-p-n transistors 8-12 times with the irradiation intensity decrease by protons from 4.07x1010 to 2.5x107 cm-2 x c-1 has been found experimentally. damages of p-n-p transistors vary in the opposite way - they are decreased 2-3 times with the irradiation intensity decrease within the same limits. the dependence of damages on intansity of proton irradiation occurs at the dose rate by three orders less than it has been observed for electron irradiation. the results obtained are explained by the dependence of radiation defectoformation reactions on charge state of defects with account for the role of formation of disordering regions upon proton irradiation [ru

  16. All-optical transistor- and diode-action and logic gates based on anisotropic nonlinear responsive liquid crystal

    Science.gov (United States)

    Wang, Cheng-Yu; Chen, Chun-Wei; Jau, Hung-Chang; Li, Cheng-Chang; Cheng, Chiao-Yu; Wang, Chun-Ta; Leng, Shi-Ee; Khoo, Iam-Choon; Lin, Tsung-Hsien

    2016-01-01

    In this paper, we show that anisotropic photosensitive nematic liquid crystals (PNLC) made by incorporating anisotropic absorbing dyes are promising candidates for constructing all-optical elements by virtue of the extraordinarily large optical nonlinearity of the nematic host. In particular, we have demonstrated several room-temperature ‘prototype’ PNLC-based all-optical devices such as optical diode, optical transistor and all primary logic gate operations (OR, AND, NOT) based on such optical transistor. Owing to the anisotropic absorption property and the optical activity of the twist alignment nematic cell, spatially non-reciprocal transmission response can be obtained within a sizeable optical isolation region of ~210 mW. Exploiting the same mechanisms, a tri-terminal configuration as an all-optical analogue of a bipolar junction transistor is fabricated. Its ability to be switched by an optical field enables us to realize an all-optical transistor and demonstrate cascadability, signal fan-out, logic restoration, and various logical gate operations such as OR, AND and NOT. Due to the possibility of synthesizing anisotropic dyes and wide ranging choice of liquid crystals nonlinear optical mechanisms, these all-optical operations can be optimized to have much lower thresholds and faster response speeds. The demonstrated capabilities of these devices have shown great potential in all-optical control system and photonic integrated circuits. PMID:27491391

  17. All-optical transistor- and diode-action and logic gates based on anisotropic nonlinear responsive liquid crystal.

    Science.gov (United States)

    Wang, Cheng-Yu; Chen, Chun-Wei; Jau, Hung-Chang; Li, Cheng-Chang; Cheng, Chiao-Yu; Wang, Chun-Ta; Leng, Shi-Ee; Khoo, Iam-Choon; Lin, Tsung-Hsien

    2016-08-05

    In this paper, we show that anisotropic photosensitive nematic liquid crystals (PNLC) made by incorporating anisotropic absorbing dyes are promising candidates for constructing all-optical elements by virtue of the extraordinarily large optical nonlinearity of the nematic host. In particular, we have demonstrated several room-temperature 'prototype' PNLC-based all-optical devices such as optical diode, optical transistor and all primary logic gate operations (OR, AND, NOT) based on such optical transistor. Owing to the anisotropic absorption property and the optical activity of the twist alignment nematic cell, spatially non-reciprocal transmission response can be obtained within a sizeable optical isolation region of ~210 mW. Exploiting the same mechanisms, a tri-terminal configuration as an all-optical analogue of a bipolar junction transistor is fabricated. Its ability to be switched by an optical field enables us to realize an all-optical transistor and demonstrate cascadability, signal fan-out, logic restoration, and various logical gate operations such as OR, AND and NOT. Due to the possibility of synthesizing anisotropic dyes and wide ranging choice of liquid crystals nonlinear optical mechanisms, these all-optical operations can be optimized to have much lower thresholds and faster response speeds. The demonstrated capabilities of these devices have shown great potential in all-optical control system and photonic integrated circuits.

  18. Reliability of GaAs processes for space applications

    OpenAIRE

    Peray, J.F; Fiers, C.; Crudo, P.; Jacobelli, C.

    1992-01-01

    This paper reviews the reliability of GaAs MMICs processes for low noise and power applications in future space systems. Each technology and library element were evaluated in terms of reliability. Results present main data of each process and an understanding of the causes of each failure modes. Improvements methodology is explained and first results are showed.

  19. Gallium arsenide (GaAs) quantum photonic waveguide circuits

    Science.gov (United States)

    Wang, Jianwei; Santamato, Alberto; Jiang, Pisu; Bonneau, Damien; Engin, Erman; Silverstone, Joshua W.; Lermer, Matthias; Beetz, Johannes; Kamp, Martin; Höfling, Sven; Tanner, Michael G.; Natarajan, Chandra M.; Hadfield, Robert H.; Dorenbos, Sander N.; Zwiller, Val; O'Brien, Jeremy L.; Thompson, Mark G.

    2014-09-01

    Integrated quantum photonics is a promising approach for future practical and large-scale quantum information processing technologies, with the prospect of on-chip generation, manipulation and measurement of complex quantum states of light. The gallium arsenide (GaAs) material system is a promising technology platform, and has already successfully demonstrated key components including waveguide integrated single-photon sources and integrated single-photon detectors. However, quantum circuits capable of manipulating quantum states of light have so far not been investigated in this material system. Here, we report GaAs photonic circuits for the manipulation of single-photon and two-photon states. Two-photon quantum interference with a visibility of 94.9±1.3% was observed in GaAs directional couplers. Classical and quantum interference fringes with visibilities of 98.6±1.3% and 84.4±1.5% respectively were demonstrated in Mach-Zehnder interferometers exploiting the electro-optic Pockels effect. This work paves the way for a fully integrated quantum technology platform based on the GaAs material system.

  20. Picosecond relaxation of X-ray excited GaAs

    Czech Academy of Sciences Publication Activity Database

    Tkachenko, V.; Medvedev, Nikita; Lipp, V.; Ziaja, B.

    2017-01-01

    Roč. 24, Sep (2017), s. 15-21 ISSN 1574-1818 Institutional support: RVO:68378271 Keywords : GaAS * X-ray excitation * picosecond relaxation Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 0.908, year: 2016

  1. GaAs Photovoltaics on Polycrystalline Ge Substrates

    Science.gov (United States)

    Wilt, David M.; Pal, AnnaMaria T.; McNatt, Jeremiah S.; Wolford, David S.; Landis, Geoffrey A.; Smith, Mark A.; Scheiman, David; Jenkins, Phillip P.; McElroy Bruce

    2007-01-01

    High efficiency III-V multijunction solar cells deposited on metal foil or even polymer substrates can provide tremendous advantages in mass and stowage, particularly for planetary missions. As a first step towards that goal, poly-crystalline p/i/n GaAs solar cells are under development on polycrystalline Ge substrates. Organo Metallic Vapor Phase Epitaxy (OMVPE) parameters for pre-growth bake, nucleation and deposition have been examined. Single junction p/i/n GaAs photovoltaic devices, incorporating InGaP front and back window layers, have been grown and processed. Device performance has shown a dependence upon the thickness of a GaAs buffer layer deposited between the Ge substrate and the active device structure. A thick (2 m) GaAs buffer provides for both increased average device performance as well as reduced sensitivity to variations in grain size and orientation. Illumination under IR light (lambda > 1 micron), the cells showed a Voc, demonstrating the presence of an unintended photoactive junction at the GaAs/Ge interface. The presence of this junction limited the efficiency to approx.13% (estimated with an anti-refection coating) due to the current mismatch and lack of tunnel junction interconnect.

  2. Terahertz radiation from delta-doped GaAs

    DEFF Research Database (Denmark)

    Birkedal, Dan; Hansen, Ole; Sørensen, Claus Birger

    1994-01-01

    Terahertz pulse emission from four different delta-doped molecular beam epitaxially grown GaAs samples is studied. We observe a decrease of the emitted THz pulse amplitude as the distance of the delta-doped layer from the surface is increased, and a change in polarity of the THz pulses as compare...

  3. Density-dependent electron scattering in photoexcited GaAs

    DEFF Research Database (Denmark)

    Mics, Zoltán; D'’Angio, Andrea; Jensen, Søren A.

    2013-01-01

    —In a series of systematic optical pump - terahertz probe experiments we study the density-dependent electron scattering rate in photoexcited GaAs in a large range of carrier densities. The electron scattering time decreases by as much as a factor of 4, from 320 to 60 fs, as the electron density...

  4. Status of GaAs solar cell production

    Science.gov (United States)

    Yeh, Milton; Ho, Frank; Iles, Peter A.

    1989-01-01

    Recent experience in producing GaAs solar cells, to meet the full requirements of space-array manufacturers is reviewed. The main problems have been in extending MOCVD technology to provide high throughput of high quality epitaxial layers, and to integrate the other important factors needed to meet the full range of user requirements. Some discussion of evolutionary changes is also given.

  5. Growth and characterization of metamorphic InAs/GaSb tunnel heterojunction on GaAs by molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jheng-Sin; Clavel, Michael B.; Hudait, Mantu K., E-mail: mantu.hudait@vt.edu [Advanced Devices and Sustainable Energy Laboratory (ADSEL), Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Pandey, Rahul [Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Datta, Suman [Electrical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States); Meeker, Michael; Khodaparast, Giti A. [Department of Physics, Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2016-06-28

    The structural, morphological, optical, and electrical transport characteristics of a metamorphic, broken-gap InAs/GaSb p-i-n tunnel diode structure, grown by molecular beam epitaxy on GaAs, were demonstrated. Precise shutter sequences were implemented for the strain-balanced InAs/GaSb active layer growth on GaAs, as corroborated by high-resolution X-ray analysis. Cross-sectional transmission electron microscopy and detailed micrograph analysis demonstrated strain relaxation primarily via the formation of 90° Lomer misfit dislocations (MDs) exhibiting a 5.6 nm spacing and intermittent 60° MDs at the GaSb/GaAs heterointerface, which was further supported by a minimal lattice tilt of 180 arc sec observed during X-ray analysis. Selective area diffraction and Fast Fourier Transform patterns confirmed the full relaxation of the GaSb buffer layer and quasi-ideal, strain-balanced InAs/GaSb heteroepitaxy. Temperature-dependent photoluminescence measurements demonstrated the optical band gap of the GaSb layer. Strong optical signal at room temperature from this structure supports a high-quality material synthesis. Current–voltage characteristics of fabricated InAs/GaSb p-i-n tunnel diodes measured at 77 K and 290 K demonstrated two bias-dependent transport mechanisms. The Shockley–Read–Hall generation–recombination mechanism at low bias and band-to-band tunneling transport at high bias confirmed the p-i-n tunnel diode operation. This elucidated the importance of defect control in metamorphic InAs/GaSb tunnel diodes for the implementation of low-voltage and high-performance tunnel field effect transistor applications.

  6. 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.

  7. 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.

  8. Experimental Study of Fast Neutron Irradiation on Si Transistor

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Sung Ho; Sun, Gwang Min; Baek, Ha ni; Jin, Seong Bok; Hoang, Sy Minh Tuan [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    Bipolar junction transistors (BJTs) are applied in many industrial fields. BJT is a three-terminal device with an important feature in that the current through two terminals can be controlled by small changes we make in the current or voltage at the third terminal. This control feature allows us to amplify small AC signals or to switch the device from an on state and off state and back. These two operations, amplification and switching, are the basis of a host of electronic functions. This study will investigate the electrical characteristics of a p-n-p BJT, such as the base current and collector current for fast neutron irradiation. Fast neutron irradiation can cause displacement damage in the Si bulk. In this paper, the electrical characteristics of a p-n-p BJT such as a base current and collector current are investigated for fast neutron irradiation. The experimental results show that the base current is increased and the collector current is decreased after fast neutron irradiation. These results indicate that the displacement damage caused by fast neutron irradiation increases the recombination rate of minority carriers and resistors.

  9. Bipolar polygenic loading and bipolar spectrum features in major depressive disorder

    NARCIS (Netherlands)

    Wiste, Anna; Robinson, Elise B.; Milaneschi, Yuri; Meier, Sandra; Ripke, Stephan; Clements, Caitlin C.; Fitzmaurice, Garrett M.; Rietschel, Marcella; Penninx, Brenda W.; Smoller, Jordan W.; Perlis, Roy H.

    Objectives Family and genetic studies indicate overlapping liability for major depressive disorder and bipolar disorder. The purpose of the present study was to determine whether this shared genetic liability influences clinical presentation. Methods A polygenic risk score for bipolar disorder,

  10. Basic matrix algebra and transistor circuits

    CERN Document Server

    Zelinger, G

    1963-01-01

    Basic Matrix Algebra and Transistor Circuits deals with mastering the techniques of matrix algebra for application in transistors. This book attempts to unify fundamental subjects, such as matrix algebra, four-terminal network theory, transistor equivalent circuits, and pertinent design matters. Part I of this book focuses on basic matrix algebra of four-terminal networks, with descriptions of the different systems of matrices. This part also discusses both simple and complex network configurations and their associated transmission. This discussion is followed by the alternative methods of de

  11. Scaling Beyond Moore: Single Electron Transistor and Single Atom Transistor Integration on CMOS

    OpenAIRE

    Deshpande , Veeresh

    2012-01-01

    Continuous scaling of MOSFET dimensions has led us to the era of nanoelectronics. Multigate FET (MuGFET) architecture with 'nanowire channel'is being considered as one feasible enabler of MOSFET scaling to end-of-roadmap. Alongside classical CMOS or Moore's law scaling, many novel device proposals exploiting nanoscale phenomena have been made. Single Electron Transistor (SET), with its unique 'Coulomb Blockade' phenomena, and Single Atom Transistor (SAT), as an ultimately scaled transistor, a...

  12. Spin dynamics in GaAs and (110)-GaAs heterostructures; Spindynamik in GaAs und (110)-GaAs-Heterostrukturen

    Energy Technology Data Exchange (ETDEWEB)

    Oertel, Stefan

    2012-07-01

    This thesis investigates the spin dynamics in both bulk GaAs and (llO)GaAs heterostructures using time- and polarization-resolved photoluminescence spectroscopy. In bulk GaAs the spin relaxation t ime is measured for the first time in the high temperature regime from 280 K to 400 K and is compared to numerical calculations. The numerical calculations are based on the spin relaxation theory of the Dyakonov-Perel mechanism effected by momentum scattering with polar optical phonons and electron-electron scattering and are in good agreement with the experimental results. Measurements of the dependence on the electron density serve to determine the energy dependent proportional factor between the electron density and the effective electron-electron scattering time. Also in bulk GaAs the interaction between the electron spin system and the nuclear spin system is investigated. The measured electron Lande g-factor under the influence of the nuclear magnetic field is used as an indicator to monitor the temporal evolution of the nuclear magnetic field under sustained dynamic nuclear polarization. Measurements with polarization modulated excitation enable the determination of the relevant time scale at which dynamic nuclear polarization takes place. Furthermore, the temporal evolution of the measured electron Lande g-factor shows the complex interplay of the dynamic nuclear polarization, the nuclear spin diffusion and the nuclear spin relaxation. In symmetric (110)-GaAs quantum wells the dependence of the inplane anisotropy of the electron Lande g-factor on the quantum well thickness is determined experimentally. The measurements are in very good agreement with calculations based upon k . p-theory and reveal a maximum of the anisotropy at maximum carrier localization in the quantum well. The origin of the anisotropy that is not present in symmetric (001) quantum wells is qualitatively described by means of a simplified model based on fourth-order perturbation theory. A

  13. Unsplit bipolar pulse forming line

    Science.gov (United States)

    Rhodes, Mark A [Pleasanton, CA

    2011-05-24

    A bipolar pulse forming transmission line module and system for linear induction accelerators having first, second, third, and fourth planar conductors which form a sequentially arranged interleaved stack having opposing first and second ends, with dielectric layers between the conductors. The first and second planar conductors are connected to each other at the first end, and the first and fourth planar conductors are connected to each other at the second end via a shorting plate. The third planar conductor is electrically connectable to a high voltage source, and an internal switch functions to short at the first end a high voltage from the third planar conductor to 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.

  14. Course of Subthreshold Bipolar Disorder in Youth: Diagnostic Progression from Bipolar Disorder Not Otherwise Specified

    Science.gov (United States)

    Axelson, David A.; Birmaher, Boris; Strober, Michael A.; Goldstein, Benjamin I.; Ha, Wonho; Gill, Mary Kay; Goldstein, Tina R.; Yen, Shirley; Hower, Heather; Hunt, Jeffrey I.; Liao, Fangzi; Iyengar, Satish; Dickstein, Daniel; Kim, Eunice; Ryan, Neal D.; Frankel, Erica; Keller, Martin B.

    2011-01-01

    Objective: To determine the rate of diagnostic conversion from an operationalized diagnosis of bipolar disorder not otherwise specified (BP-NOS) to bipolar I disorder (BP-I) or bipolar II disorder (BP-II) in youth over prospective follow-up and to identify factors associated with conversion. Method: Subjects were 140 children and adolescents…

  15. Bipolar (spectrum) disorder and mood stabilization: standing at the crossroads?

    OpenAIRE

    De Fruyt, Jurgen; Demyttenaere, Koen

    2007-01-01

    Diagnosis and treatment of bipolar disorder has long been a neglected discipline. Recent years have shown an upsurge in bipolar research. When compared to major depressive disorder, bipolar research still remains limited and more expert based than evidence based. In bipolar diagnosis the focus is shifting from classic mania to bipolar depression and hypomania. There is a search for bipolar signatures in symptoms and course of major depressive episodes. The criteria for hypomania are softened,...

  16. [Bipolar disorders in DSM-5].

    Science.gov (United States)

    Severus, E; Bauer, M

    2014-05-01

    In spring 2013 the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) edited by the American Psychiatric Association was published. The DSM-5 has also brought some important changes regarding bipolar disorders. The goal of this manuscript is to review the novelties in DSM-5 and to evaluate the implications of these changes. The diagnostic criteria as well as the additional remarks provided in the running text of DSM-5 were carefully appraised. For the first time diagnostic criteria are provided for disorders which up to now have been considered as subthreshold bipolar disorders. Furthermore, mixed episodes were eliminated and instead a mixed specifier was introduced. An increase in goal-directed activity/energy is now one of the obligatory symptoms for a (hypo)manic episode. Diagnostic guidance is provided as to when a (hypo)manic episode that has developed during treatment with an antidepressant has to be judged to be causally related to antidepressants and when this episode has only occurred coincidentally with antidepressant use. While some of the novelties are clearly useful, e.g. addition of increased goal-directed activity/energy as obligatory symptom for (hypo)manic episodes, this remains to be demonstrated for others, such as the definition of various subthreshold bipolar disorders.

  17. Bipolar Disorder and Obsessive Compulsive Disorder Comorbidity

    Directory of Open Access Journals (Sweden)

    Necla Keskin

    2014-08-01

    Full Text Available The comorbidity of bipolar disorder and anxiety disorders is a well known concept. Obsessive-compulsive disorder is the most commonly seen comorbid anxiety disorder in bipolar patients. Some genetic variants, neurotransmitters especially serotonergic systems and second-messenger systems are thought to be responsible for its etiology. Bipolar disorder alters the clinical aspects of obsessive compulsive disorder and is associated with poorer outcome. The determination of comorbidity between bipolar disorder and obsessive compulsive disorder is quite important for appropriate clinical management and treatment. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(4.000: 429-437

  18. 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.

  19. Lateral power transistors in integrated circuits

    CERN Document Server

    Erlbacher, Tobias

    2014-01-01

    This book details and compares recent advancements in the development of novel lateral power transistors (LDMOS devices) for integrated circuits in power electronic applications. It includes the state-of-the-art concept of double-acting RESURF topologies.

  20. Graphene Field Effect Transistors for Radiation Detection

    Data.gov (United States)

    National Aeronautics and Space Administration — This is propose to develop Graphene Field Effect Transistor based Radiation Sensors (GFET-RS) for NASA Manned Spaceflight Missions anticipated in next several...

  1. Breakdown of transistors in Marx bank circuit

    Science.gov (United States)

    Chatterjee, Amitabh

    2000-09-01

    We reconsider the mode of operation of a Marx bank circuit and analyze the secondary breakdown of transistors with shorted emitter-base. The mechanism of breakdown of the transistor when a fast rising voltage pulse is applied across is investigated. The device exhibits chaotic behavior at the breakdown point where it can go into two possible modes of breakdown. A new explanation for the working of the circuit consistent with the experimental observations is proposed.

  2. Bipolar mixed features - Results from the comparative effectiveness for bipolar disorder (Bipolar CHOICE) study.

    Science.gov (United States)

    Tohen, Mauricio; Gold, Alexandra K; Sylvia, Louisa G; Montana, Rebecca E; McElroy, Susan L; Thase, Michael E; Rabideau, Dustin J; Nierenberg, Andrew A; Reilly-Harrington, Noreen A; Friedman, Edward S; Shelton, Richard C; Bowden, Charles L; Singh, Vivek; Deckersbach, Thilo; Ketter, Terence A; Calabrese, Joseph R; Bobo, William V; McInnis, Melvin G

    2017-08-01

    DSM-5 changed the criteria from DSM-IV for mixed features in mood disorder episodes to include non-overlapping symptoms of depression and hypomania/mania. It is unknown if, by changing these criteria, the same group would qualify for mixed features. We assessed how those meeting DSM-5 criteria for mixed features compare to those meeting DSM-IV criteria. We analyzed data from 482 adult bipolar patients in Bipolar CHOICE, a randomized comparative effectiveness trial. Bipolar diagnoses were confirmed through the MINI International Neuropsychiatric Interview (MINI). Presence and severity of mood symptoms were collected with the Bipolar Inventory of Symptoms Scale (BISS) and linked to DSM-5 and DSM-IV mixed features criteria. Baseline demographics and clinical variables were compared between mood episode groups using ANOVA for continuous variables and chi-square tests for categorical variables. At baseline, the frequency of DSM-IV mixed episodes diagnoses obtained with the MINI was 17% and with the BISS was 20%. Using DSM-5 criteria, 9% of participants met criteria for hypomania/mania with mixed features and 12% met criteria for a depressive episode with mixed features. Symptom severity was also associated with increased mixed features with a high rate of mixed features in patients with mania/hypomania (63.8%) relative to those with depression (8.0%). Data on mixed features were collected at baseline only and thus do not reflect potential patterns in mixed features within this sample across the study duration. The DSM-5 narrower, non-overlapping definition of mixed episodes resulted in fewer patients who met mixed criteria compared to DSM-IV. Copyright © 2017. Published by Elsevier B.V.

  3. Theoretical investigation of GaAsBi/GaAsN tunneling field-effect transistors with type-II staggered tunneling junction

    Science.gov (United States)

    Wang, Yibo; Liu, Yan; Han, Genquan; Wang, Hongjuan; Zhang, Chunfu; Zhang, Jincheng; Hao, Yue

    2017-06-01

    We investigate GaAsBi/GaAsN system for the design of type-II staggered hetero tunneling field-effect transistor (hetero-TFET). Strain-symmetrized GaAsBi/GaAsN with effective lattice match to GaAs exhibits a type-II band lineup, and the effective bandgap EG,eff at interface is significantly reduced with the incorporation of Bi and N elements. The band-to-band tunneling (BTBT) rate and drive current of GaAsBi/GaAsN hetero-TFETs are boosted due to the utilizing of the type-II staggered tunneling junction with the reduced EG,eff. Numerical simulation shows that the drive current and subthreshold swing (SS) characteristics of GaAsBi/GaAsN hetero-TFETs are remarkably improved by increasing Bi and N compositions. The dilute content GaAs0.85Bi0.15/GaAs0.92N0.08 staggered hetero-nTFET achieves 7.8 and 550 times higher ION compared to InAs and In0.53Ga0.47As homo-TFETs, respectively, at the supply voltage of 0.3 V. GaAsBi/GaAsN heterostructure is a potential candidate for high performance TFET.

  4. Resistance Fluctuations in GaAs Nanowire Grids

    Directory of Open Access Journals (Sweden)

    Ivan Marasović

    2014-01-01

    Full Text Available We present a numerical study on resistance fluctuations in a series of nanowire-based grids. Each grid is made of GaAs nanowires arranged in parallel with metallic contacts crossing all nanowires perpendicularly. Electrical properties of GaAs nanowires known from previous experimental research are used as input parameters in the simulation procedure. Due to the nonhomogeneous doping, the resistivity changes along nanowire. Allowing two possible nanowire orientations (“upwards” or “downwards”, the resulting grid is partially disordered in vertical direction which causes resistance fluctuations. The system is modeled using a two-dimensional random resistor network. Transfer-matrix computation algorithm is used to calculate the total network resistance. It is found that probability density function (PDF of resistance fluctuations for a series of nanowire grids changes from Gaussian behavior towards the Bramwell-Holdsworth-Pinton distribution when both nanowire orientations are equally represented in the grid.

  5. GaAs nanocrystals: Structure and vibrational properties

    International Nuclear Information System (INIS)

    Nayak, J.; Sahu, S.N.; Nozaki, S.

    2006-01-01

    GaAs nanocrystals were grown on indium tin oxide substrate by an electrodeposition technique. Atomic force microscopic measurement indicates an increase in the size of the nanocrystal with decrease in the electrolysis current density accompanied by the change in the shape of the crystallite. Transmission electron microscopic measurements identify the crystallite sizes to be in the range of 10-15 nm and the crystal structure to be orthorhombic. On account of the quantum size effect, the first optical transition was blue shifted with respect to the band gap of the bulk GaAs and the excitonic peak appeared prominent. A localized phonon mode ascribed to certain point defect occurred in the room temperature micro-Raman spectrum

  6. Testing a GaAs cathode in SRF gun

    International Nuclear Information System (INIS)

    Wang, E.; Kewisch, J.; Ben-Zvi, I.; Burrill, A.; Rao, T.; Wu, Q.; Holmes, D.

    2011-01-01

    RF electron guns with a strained superlattice GaAs cathode are expected to generate polarized electron beams of higher brightness and lower emittance than do DC guns, due to their higher field gradient at the cathode's surface and lower cathode temperature. We plan to install a bulk GaAs:Cs in a SRF gun to evaluate the performance of both the gun and the cathode in this environment. The status of this project is: In our 1.3 GHz 1/2 cell SRF gun, the vacuum can be maintained at nearly 10 -12 Torr because of cryo-pumping at 2K. With conventional activation of bulk GaAs, we obtained a QE of 10% at 532 nm, with lifetime of more than 3 days in the preparation chamber and have shown that it can survive in transport from the preparation chamber to the gun. The beam line has been assembled and we are exploring the best conditions for baking the cathode under vacuum. We report here the progress of our test of the GaAs cathode in the SRF gun. Future particle accelerators, such as eRHIC and the ILC require high-brightness, high-current polarized electrons. Strained superlattice GaAs:Cs has been shown to be an efficient cathode for producing polarized electrons. Activation of GaAs with Cs,O(F) lowers the electron affinity and makes it energetically possible for all the electrons, excited into the conduction band that drift or diffuse to the emission surface, to escape into the vacuum. Presently, all operating polarized electron sources, such as the CEBAF, are DC guns. In these devices, the excellent ultra-high vacuum extends the lifetime of the cathode. However, the low field gradient on the photocathode's emission surface of the DC guns limits the beam quality. The higher accelerating gradients, possible in the RF guns, generate a far better beam. Until recently, most RF guns operated at room temperature, limiting the vacuum to ∼10 -9 Torr. This destroys the GaAs's NEA surface. The SRF guns combine the excellent vacuum conditions of DC guns and the high accelerating

  7. [Thinking organization and defense mechanisms in bipolar disorders. Clinical and psychopathological study on bipolar I and bipolar II].

    Science.gov (United States)

    Lo Baido, Rosa; Di Blasi, Marie; Alfano, Pietro; Audino, Palma; Bellavia, Carmela; Blando, Anna Antonia; Merendino, Adelaide; Messina, Rossana; Poma, Maria Luisa; La Grutta, Sabina

    2013-01-01

    The aim of this research is to explore the psychical functioning in bipolar I or bipolar II disorder people through the analysis and comparison of their thought styles and defense patterns. 29 bipolar I and bipolar II people afferent to Palermo University Policlinical Psychriatic Hospital Department were selected during the whole 2009-2010 year. The following tests were administred: Wechsler Adult Intelligent Scale-R (WAIS-R) in order to measure the general cognitive function; Defense Mechanisms Inventory (DMI) in order to measure defense patterns. Afterwards, the results of the two tests were analysed and compared. Bipolar disorder people use cognitive mechanisms and defense strategies that are very different from standard population. Bipolar I subjects show both wider and more serious cognitive deterioration and stricter defense mechanisms than bipolar II subjects. Generally bipolar patients show an immature personality based on archaic mechanisms that can be found in all the spheres of their personality: emotions, cognition, Ego-strength, adaptability to reality. The peculiar achieved cognitive and defense profile leads to important considerations about how psychological strategies can contribute to use "bespoke" treatments for these patients.

  8. Unjuk Kerja Catu Daya 12 Volt 2a Dengan Pass Element Transistor Npn Dan Pnp

    OpenAIRE

    Fathoni, Fathoni

    2010-01-01

    Transistor pelewat (pass element transistor) yang dipasang pada rangkain catu daya yang menggunakan IC regulator 3 terminal adalah untuk booster arus output. Ada dua cara pemasangan transistor pelewat yang umum digunakan, yaitu dengan transistor pnp dan npn. Transistor pnp dipasang dengan basis transistor yang terhubung pada input IC regulator sedangkan transistor npn dipasang dengan basis transistor yang terhubung pada output IC regulator.Untuk mengetahui unjuk kerja dari kedua ...

  9. Epitaxial growth on porous GaAs substrates

    Czech Academy of Sciences Publication Activity Database

    Grym, Jan; Nohavica, Dušan; Gladkov, Petar; Hulicius, Eduard; Pangrác, Jiří; Piksová, K.

    2013-01-01

    Roč. 16, č. 1 (2013), s. 59-64 ISSN 1631-0748 R&D Projects: GA ČR GAP102/10/1201; GA ČR GAP108/10/0253 Institutional support: RVO:67985882 ; RVO:68378271 Keywords : Electrochemical etching * Porous semiconductors * Epitaxial growth * GaAs Subject RIV: BH - Optics, Masers, Lasers; JA - Electronics ; Optoelectronics, Electrical Engineering (FZU-D) Impact factor: 1.483, year: 2013

  10. Solar heating of GaAs nanowire solar cells.

    Science.gov (United States)

    Wu, Shao-Hua; Povinelli, Michelle L

    2015-11-30

    We use a coupled thermal-optical approach to model the operating temperature rise in GaAs nanowire solar cells. We find that despite more highly concentrated light absorption and lower thermal conductivity, the overall temperature rise in a nanowire structure is no higher than in a planar structure. Moreover, coating the nanowires with a transparent polymer can increase the radiative cooling power by 2.2 times, lowering the operating temperature by nearly 7 K.

  11. Gallium arsenide (GaAs) solar cell modeling studies

    Science.gov (United States)

    Heinbockel, J. H.

    1980-01-01

    Various models were constructed which will allow for the variation of system components. Computer studies were then performed using the models constructed in order to study the effects of various system changes. In particular, GaAs and Si flat plate solar power arrays were studied and compared. Series and shunt resistance models were constructed. Models for the chemical kinetics of the annealing process were prepared. For all models constructed, various parametric studies were performed.

  12. Monolithic GaAs surface acoustic wave chemical microsensor array

    Energy Technology Data Exchange (ETDEWEB)

    HIETALA,VINCENT M.; CASALNUOVO,STEPHEN A.; HELLER,EDWIN J.; WENDT,JOEL R.; FRYE-MASON,GREGORY CHARLES; BACA,ALBERT G.

    2000-03-09

    A four-channel surface acoustic wave (SAW) chemical sensor array with associated RF electronics is monolithically integrated onto one GaAs IC. The sensor operates at 690 MHz from an on-chip SAW based oscillator and provides simple DC voltage outputs by using integrated phase detectors. This sensor array represents a significant advance in microsensor technology offering miniaturization, increased chemical selectivity, simplified system assembly, improved sensitivity, and inherent temperature compensation.

  13. Performance Comparison of Top and Bottom Contact Gallium Arsenide (GaAs) Solar Cell

    Science.gov (United States)

    2014-09-01

    Performance Comparison of Top and Bottom Contact Gallium Arsenide (GaAs) Solar Cell by Naresh C Das ARL-TR-7054 September 2014...September 2014 Performance Comparison of Top and Bottom Contact Gallium Arsenide (GaAs) Solar Cell Naresh C Das Sensors and Electron...From - To) 01/02/2014–07/15/2014 4. TITLE AND SUBTITLE Performance Comparison of Top and Bottom Contact Gallium Arsenide (GaAs) Solar Cell 5a

  14. Fabrication and Characterization of a Single Hole Transistor in p-type GaAs/AlGaAs Heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Tracy, Lisa A [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Reno, John L. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Hargett, Terry W. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    Most spin qubit research to date has focused on manipulating single electron spins in quantum dots. However, hole spins are predicted to have some advantages over electron spins, such as reduced coupling to host semiconductor nuclear spins and the ability to control hole spins electrically using the large spin-orbit interaction. Building on recent advances in fabricating high-mobility 2D hole systems in GaAs/AlGaAs heterostructures at Sandia, we fabricate and characterize single hole transistors in GaAs. We demonstrate p-type double quantum dot devices with few-hole occupation, which could be used to study the physics of individual hole spins and control over coupling between hole spins, looking towards eventual applications in quantum computing. Intentionally left blank

  15. Poorer sustained attention in bipolar I than bipolar II disorder

    Directory of Open Access Journals (Sweden)

    Chen Shih-Heng

    2010-02-01

    Full Text Available Abstract Background Nearly all information processing during cognitive processing takes place during periods of sustained attention. Sustained attention deficit is among the most commonly reported impairments in bipolar disorder (BP. The majority of previous studies have only focused on bipolar I disorder (BP I, owing to underdiagnosis or misdiagnosis of bipolar II disorder (BP II. With the refinement of the bipolar spectrum paradigm, the goal of this study was to compare the sustained attention of interepisode patients with BP I to those with BP II. Methods In all, 51 interepisode BP patients (22 with BP I and 29 with BP II and 20 healthy controls participated in this study. The severity of psychiatric symptoms was assessed by the 17-item Hamilton Depression Rating Scale and the Young Mania Rating Scale. All participants undertook Conners' Continuous Performance Test II (CPT-II to evaluate sustained attention. Results After controlling for the severity of symptoms, age and years of education, BP I patients had a significantly longer reaction times (F(2,68 = 7.648, P = 0.001, worse detectability (d' values (F(2,68 = 6.313, P = 0.003 and more commission errors (F(2,68 = 6.182, P = 0.004 than BP II patients and healthy controls. BP II patients and controls scored significantly higher than BP I patients for d' (F = 6.313, P = 0.003. No significant difference was found among the three groups in omission errors and no significant correlations were observed between CPT-II performance and clinical characteristics in the three groups. Conclusions These findings suggested that impairments in sustained attention might be more representative of BP I than BP II after controlling for the severity of symptoms, age, years of education and reaction time on the attentional test. A longitudinal follow-up study design with a larger sample size might be needed to provide more information on chronological sustained attention deficit in BP patients, and to illustrate

  16. Defects and diffusion in Si+ implanted GaAs

    International Nuclear Information System (INIS)

    Jones, K.S.; Robinson, H.G.; Deal, M.D.; Lee, C.C.; Allen, E.L.

    1993-05-01

    The effect of extended defects on the diffusion of ion implanted species is an area of concern in the development of process simulators for GaAs. This study explores the effect of type 1 extended defects including voids and dislocation loops on the diffusion of Si implanted into GaAs. Semi-insulating GaAs wafers were implanted with 1 x 10 14 /cm 2 Si + at implant temperatures between -51 C and 80 C and at energies ranging from 20 keV to 200 keV. SIMS results show that the diffusivity of Si decreases with both increasing implant temperature and increasing implant energy. At the same time extrinsic dislocation loop concentrations also increased. For the implant conditions studied, no voids were observed. The diffusion results can only be reconciled with the TEM results if the dislocation loops are behaving in a reactive rather than proactive manner. In other words, the changes in vacancy concentration that are affecting the diffusivity are also affecting the loop concentration. This model is supported by evidence that Si diffusivity is enhanced over the same time interval the dislocation loops are dissolving which is consistent with the loops having a reactive role. It remains unclear whether the existence of loops significantly affects the total concentration of vacancies and thus diffusion by acting as a competing sink

  17. Metallization systems for stable ohmic contacts to GaAs

    International Nuclear Information System (INIS)

    Tandon, J.L.; Douglas, K.D.; Vendura, G.; Kolawa, E.; So, F.C.T.; Nicolet, M.A.

    1986-01-01

    A metallization scheme to form reproducible and stable ohmic contacts to GaAs is described. The approach is based on the configuration: GaAs/X/Y/Z; where X is a thin metal film (e.g. Pt, Ti, Pd, Ru), Y is an electrically conducting diffusion barrier layer (TiN, W or W/sub 0.7/N/sub 0.3/), and Z is a thick metal layer (e.g. Ag) typically required for bonding or soldering purposes. The value and reproducibility of the contact resistance in these metallization systems results from the uniform steady-state solid-phase reaction of the metal X with GaAs. The stability of the contacts is achieved by the diffusion barrier layer Y, which not only confines the reaction of X with GaAs, but also prevents the top metal layer Z from interfering with this reaction. Applications of such contacts in fabricating stable solar cells are also discussed

  18. Scanning tunneling microscopy study of GaAs(001) surfaces

    Science.gov (United States)

    Xue, Qi-Kun; Hashizume, T.; Sakurai, T.

    1999-03-01

    While GaAs(001) is the most commonly used substrate in fabrication of wireless and opto-electronic devices based on III-V compound semiconductors by molecular beam epitaxy (MBE), metallorganic chemical vapor deposition (MOCVD) and related techniques, its surface structure have been disputed since the beginning of development of the techniques. Invention of scanning tunneling microscopy (STM) has revolutionized the approach of surface/interface investigation, contributing greatly in the atomistic understanding of the GaAs surface phases. This paper reviews the STM studies of principal reconstructions, from As-rich c(4×4), 2×4, 2×6 to Ga-rich 4×2 and 4×6, found on the GaAs (001) surface. These studies, together with advanced theoretical efforts, have helped us to establish a unified structural model for various reconstructions, with which we can now explain most of the observations and long-standing controversies in atomic structures and surface stoichiometries.

  19. Modelling, development and optimization of integrated power LDMOS transistor. Performance limits in terms of energy; Modelisation, conception et optimisation de composant de puissance lateral DMOS integre. Etude des limites de performance en energie

    Energy Technology Data Exchange (ETDEWEB)

    Farenc, D.

    1997-12-16

    Technologies for Smart Power Integrated Circuits combine into a single chip Bipolar and CMOS transistors, plus power with lateral or vertical DMOS transistors. Complexity which has been increasing dramatically since the mid-80`s has allowed to integrate, into a single monolithic solution, entire systems. This thesis deals with the modelling, conception and test of the power integrated LDMOS transistor. The power LDMOS transistor is used as a switching device. It is characterized by two parameters which are the Specific On-resistance R{sub sp} and the breakdown voltage BV{sub DSS}. The LDMOS transistor developed for the new Smart Power technology exhibits a Specific On-resistance of 200 m{Omega}{sup *}mm{sup 2} and a breakdown voltage of 60 V. This device is dedicated to automotive applications. A reduction of the power device which is achieved with a low Specific On-resistance puts forward new issues such as the maximum Energy capability. When the power device is switched-off on an inductive load, a certain amount of energy is dissipated; if it is beyond a certain limit, the device is destroyed. Our goal is to determine the energy limits which are associated with our new Power integrated LDMOS transistor. (author) 28 refs.

  20. Identification a novel mononucleotide deletion mutation in GAA in pompe disease patients

    Directory of Open Access Journals (Sweden)

    Milad Ebrahimi

    2017-01-01

    Full Text Available Background: Mutations in the acid alpha-glucosidase (GAA gene usually lead to reduced GAA activity. In this study, we analyzed the mutations of GAA and GAA enzyme activity from one sibling suspected Pompe disease and their first-degree relatives. Materials and Methods: In this cross-sectional study, GAA enzyme activity assay was assessed using tandem mass spectrometry. Polymerase chain reaction and Sanger sequencing were performed for GAA analysis. Results: GAA enzyme activity was significantly decreased in patients compared to the normal range (P = 0.02. Two individuals showed ten alterations in the GAA sequence, in which one of them (c. 1650del G has not been previously described in the literature. A single Guanine deletion (del-G was detected at codon 551 in exon 12. Conclusion: According to the literature, the detected change is a novel mutation. We hypothesized that the discovered deletion in the GAA might lead to a reduced activity of the gene product.

  1. Lateral terahertz hot-electron bolometer based on an array of Sn nanothreads in GaAs

    Science.gov (United States)

    Ponomarev, D. S.; Lavrukhin, D. V.; Yachmenev, A. E.; Khabibullin, R. A.; Semenikhin, I. E.; Vyurkov, V. V.; Ryzhii, M.; Otsuji, T.; Ryzhii, V.

    2018-04-01

    We report on the proposal and the theoretical and experimental studies of the terahertz hot-electron bolometer (THz HEB) based on a gated GaAs structure like the field-effect transistor with the array of parallel Sn nanothreads (Sn-NTs). The operation of the HEB is associated with an increase in the density of the delocalized electrons due to their heating by the incoming THz radiation. The quantum and the classical device models were developed, the quantum one was based on the self-consistent solution of the Poisson and Schrödinger equations, the classical model involved the Poisson equation and density of states omitting quantization. We calculated the electron energy distributions in the channels formed around the Sn-NTs for different gate voltages and found the fraction of the delocalized electrons propagating across the energy barriers between the NTs. Since the fraction of the delocalized electrons strongly depends on the average electron energy (effective temperature), the proposed THz HEB can exhibit an elevated responsivity compared with the HEBs based on more standard heterostructures. Due to a substantial anisotropy of the device structure, the THz HEB may demonstrate a noticeable polarization selectivity of the response to the in-plane polarized THz radiation. The features of the THz HEB might be useful in their practical applications in biology, medicine and material science.

  2. Analysis of DC and analog/RF performance on Cyl-GAA-TFET using distinct device geometry

    Science.gov (United States)

    Vishvakarma, S. K.; Beohar, Ankur; Vijayvargiya, Vikas; Trivedi, Priyal

    2017-07-01

    In this paper, analysis of DC and analog/RF performance on cylindrical gate-all-around tunnel field-effect transistor (TFET) has been made using distinct device geometry. Firstly, performance parameters of GAA-TFET are analyzed in terms of drain current, gate capacitances, transconductance, source-drain conductance at different radii and channel length. Furthermore, we also produce the geometrical analysis towards the optimized investigation of radio frequency parameters like cut-off frequency, maximum oscillation frequency and gain bandwidth product using a 3D technology computer-aided design ATLAS. Due to band-to-band tunneling based current mechanism unlike MOSFET, gate-bias dependence values as primary parameters of TFET differ. We also analyze that the maximum current occurs when radii of Si is around 8 nm due to high gate controllability over channel with reduced fringing effects and also there is no change in the current of TFET on varying its length from 100 to 40 nm. However current starts to increase when channel length is further reduced for 40 to 30 nm. Both of these trades-offs affect the RF performance of the device. Project supported by the Council of Scientific and Industrial Research (CSIR) Funded Research Project, Grant No. 22/0651/14/EMR-II, Government of India.

  3. Swimming in Deep Water: Childhood Bipolar Disorder

    Science.gov (United States)

    Senokossoff, Gwyn W.; Stoddard, Kim

    2009-01-01

    The authors focused on one parent's struggles in finding a diagnosis and intervention for a child who had bipolar disorder. The authors explain the process of identification, diagnosis, and intervention of a child who had bipolar disorder. In addition to the personal story, the authors provide information on the disorder and outline strategies…

  4. 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

  5. Transient Stuttering in Catatonic Bipolar Patients

    Directory of Open Access Journals (Sweden)

    Anthony B. Joseph

    1991-01-01

    Full Text Available Two cases of transient stuttering occurring in association with catatonia and bipolar disorder are described. Affective decompensation has been associated with lateralized cerebral dysfunction, and it is hypothesized that in some bipolar catatonic patients a concomitant disorder of the lateralization of language function may lead to a variety of clinical presentations including aphasia, mutism, and stuttering.

  6. Cognitive behavioral therapy for bipolar disorders

    OpenAIRE

    Lotufo Neto, Francisco

    2004-01-01

    Descrição dos objetivos e principais técnicas da terapia comportamental cognitiva usadas para a psicoterapia das pessoas com transtorno bipolar.Objectives and main techniques of cognitive behavior therapy for the treatment of bipolar disorder patients are described.

  7. NO signaling in retinal bipolar cells.

    Science.gov (United States)

    Agurto, A; Vielma, A H; Cadiz, B; Couve, E; Schmachtenberg, O

    2017-08-01

    Nitric oxide (NO) is a neuromodulator involved in physiological and pathological processes in the retina. In the inner retina, a subgroup of amacrine cells have been shown to synthesize NO, but bipolar cells remain controversial as NO sources. This study correlates NO synthesis in dark-adapted retinas, through labeling with the NO marker DAF-FM, with neuronal nitric oxide synthase (nNOS) and inducible NOS expression, and presence of the NO receptor soluble guanylate cyclase in bipolar cells. NO containing bipolar cells were morphologically identified by dialysis of DAF fluorescent cells with intracellular dyes, or by DAF labeling followed by immunohistochemistry for nNOS and other cellular markers. DAF fluorescence was observed in all types of bipolar cells that could be identified, but the most intense DAF fluorescence was observed in bipolar cells with severed processes, supporting pathological NO signaling. Among nNOS expressing bipolar cells, type 9 was confirmed unequivocally, while types 2, 3a, 3b, 4, 5, 7, 8 and the rod bipolar cell were devoid of this enzyme. These results establish specific bipolar cell types as NO sources in the inner retina, and support the involvement of NO signaling in physiological and pathological processes in the inner retina. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Dependence of Ideality Factor in Lateral PNP Transistors on Surface Carrier Concentration

    Science.gov (United States)

    Li, Xingji; Yang, Jianqun; Barnaby, Hugh J.; Galloway, Kenneth F.; Schrimpf, Ronald D.; Fleetwood, Daniel M.; Liu, Chaoming

    2017-06-01

    The influence of surface carrier concentration on the ideality factor of excess base current (ΔIB) in gated lateral PNP (GLPNP) bipolar junction transistors (BJTs) induced by 1-MeV electrons is investigated. ΔIB in LPNP BJTs is impacted by the surface carrier density and radiation-induced interface traps. In GLPNP BJTs, the surface carrier concentration can be controlled by the voltage applied to a gate over the base region. The ideality factor changes after irradiation, and its dependence on emitter-base voltage (VEB) is a function of gate voltage. For the irradiated devices, as the gate voltage decreases from +20 to -5 V, the ideality factor for excess base current changes from a single slope to two-slope behavior. The majority carrier concentration at the surface of the base, controlled by the gate voltage, impacts the excess base current and its ideality factor.

  9. Nonactivated transport of ultradilute two-dimensional hole systems in GaAs field-effect transistors: Interaction versus disorder

    Science.gov (United States)

    Huang, Jian; Pfeiffer, L. N.; West, K. W.

    2012-01-01

    Very strongly interacting high-purity two-dimensional (2D) electron systems at temperatures T→0 demonstrate certain nonactivated insulating behaviors that are absent in more disordered systems. By measuring in dark the T dependence of the conductivity of ultrahigh-quality 2D holes with charge densities down to 7×108 cm-2, an approximate power-law behavior is identified. Moreover, the exponent exhibits a linearly decreasing density dependence which suggests an interaction-driven nature. Such an electron state is fragile to even a slight increase of disorder, which causes a crossover from nonactivated to activated conduction. The nonactivated conduction may well be a universal interaction-driven signature of an electron state of strongly correlated (semiquantum) liquid.

  10. Thyroid Functions and Bipolar Affective Disorder

    Directory of Open Access Journals (Sweden)

    Subho Chakrabarti

    2011-01-01

    Full Text Available Accumulating evidence suggests that hypothalamo-pituitary-thyroid (HPT axis dysfunction is relevant to the pathophysiology and clinical course of bipolar affective disorder. Hypothyroidism, either overt or more commonly subclinical, appears to the commonest abnormality found in bipolar disorder. The prevalence of thyroid dysfunction is also likely to be greater among patients with rapid cycling and other refractory forms of the disorder. Lithium-treatment has potent antithyroid effects and can induce hypothyroidism or exacerbate a preexisting hypothyroid state. Even minor perturbations of the HPT axis may affect the outcome of bipolar disorder, necessitating careful monitoring of thyroid functions of patients on treatment. Supplementation with high dose thyroxine can be considered in some patients with treatment-refractory bipolar disorder. Neurotransmitter, neuroimaging, and genetic studies have begun to provide clues, which could lead to an improved understanding of the thyroid-bipolar disorder connection, and more optimal ways of managing this potentially disabling condition.

  11. Diagnostic stability in pediatric bipolar disorder

    DEFF Research Database (Denmark)

    Vedel Kessing, Lars; Vradi, Eleni; Andersen, Per Kragh

    2015-01-01

    BACKGROUND: The diagnostic stability of pediatric bipolar disorder has not been investigated previously. The aim was to investigate the diagnostic stability of the ICD-10 diagnosis of pediatric mania/bipolar disorder.METHODS: All patients below 19 years of age who got a diagnosis of mania/bipolar...... disorder at least once in a period from 1994 to 2012 at psychiatric inpatient or outpatient contact in Denmark were identified in a nationwide register.RESULTS: Totally, 354 children and adolescents got a diagnosis of mania/bipolar disorder at least once; a minority, 144 patients (40.7%) got the diagnosis...... at the first contact whereas the remaining patients (210; 59.3%) got the diagnosis at later contacts before age 19. For the latter patients, the median time elapsed from first treatment contact with the psychiatric service system to the first diagnosis with a manic episode/bipolar disorder was nearly 1 year...

  12. 2017 Bipolar Plate Workshop Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Kopasz, John P. [Argonne National Lab. (ANL), Argonne, IL (United States); Benjamin, Thomas G. [Argonne National Lab. (ANL), Argonne, IL (United States); Schenck, Deanna [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-08-17

    The Bipolar Plate (BP) Workshop was held at USCAR1 in Southfield, Michigan on February 14, 2017 and included 63 participants from industry, government agencies, universities, and national laboratories with expertise in the relevant fields. The objective of the workshop was to identify research and development (R&D) needs, in particular early-stage R&D, for bipolar plates for polymer electrolyte membrane (PEM) fuel cells for transportation applications. The focus of the workshop was on materials, manufacturing, and design aspects of bipolar plates with the goal of meeting DOE’s 2020 bipolar plate targets. Of special interest was the cost target of ≤$3/kW for the bipolar plate.

  13. X-ray diffraction from single GaAs nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Biermanns, Andreas

    2012-11-12

    In recent years, developments in X-ray focussing optics have allowed to produce highly intense, coherent X-ray beams with spot sizes in the range of 100 nm and below. Together with the development of new experimental stations, X-ray diffraction techniques can now be applied to study single nanometer-sized objects. In the present work, X-ray diffraction is applied to study different aspects of the epitaxial growth of GaAs nanowires. Besides conventional diffraction methods, which employ X-ray beams with dimensions of several tens of {mu}m, special emphasis lies on the use of nanodiffraction methods which allow to study single nanowires in their as-grown state without further preparation. In particular, coherent X-ray diffraction is applied to measure simultaneously the 3-dimensional shape and lattice parameters of GaAs nanowires grown by metal-organic vapor phase epitaxy. It is observed that due to a high density of zinc-blende rotational twins within the nanowires, their lattice parameter deviates systematically from the bulk zinc-blende phase. In a second step, the initial stage in the growth of GaAs nanowires on Si (1 1 1) surfaces is studied. This nanowires, obtained by Ga-assisted growth in molecular beam epitaxy, grow predominantly in the cubic zinc-blende structure, but contain inclusions of the hexagonal wurtzite phase close to their bottom interface. Using nanodiffraction methods, the position of the different structural units along the growth axis is determined. Because the GaAs lattice is 4% larger than silicon, these nanowires release their lattice mismatch by the inclusion of dislocations at the interface. Whereas NWs with diameters below 50 nm are free of strain, a rough interface structure in nanowires with diameters above 100 nm prevents a complete plastic relaxation, leading to a residual strain at the interface that decays elastically along the growth direction. Finally, measurements on GaAs-core/InAs-shell nanowire heterostructures are presented

  14. Characterization and AlN cooling of thermally isolated bipolar transistors

    NARCIS (Netherlands)

    La Spina, L.

    2009-01-01

    Nowadays, electrothermal effects (ET) are posing fundamental issues in nearly all branches of micro- and nano-electronics. Due to either a high power dissipation level or to the aggressive electrical isolation schemes adopted to increase the speed, both high and low power devices are affected by ET

  15. The influence of degeneracy on the emitter efficiency of a bipolar transistor

    Science.gov (United States)

    Deman, H. J. J.

    1971-01-01

    An expression for the emitter efficiency is derived taking the degeneracy of the emitter into account. It is found that, even if there is no recombination of minority carriers in the emitter, degeneracy reduces the emitter efficiency. In addition this first order theory explains experimental results on temperature dependence of current gain and predicts an optimum emitter design for a fixed type of emitter profile.

  16. IGBT convertor with active snubber for soft switching. [Insulated Gate Bipolar Transistor

    Science.gov (United States)

    Masserant, B. J.; Shriver, J.; Stuart, T. A.

    1991-01-01

    This full bridge dc-dc convertor with IGBTs uses zero voltage switching (ZVS) for one leg of the bridge and zero current switching (ZCS) for the other. It is shown that an active snubber greatly improves the performance over previous methods. Experimental results are shown for a 6 kW circuit switching at 20 kHz.

  17. High-frequency noise modeling of Si(Ge) bipolar transistors

    NARCIS (Netherlands)

    Vitale, F.

    2014-01-01

    The design and the optimization of electronic systems often requires a detailed knowledge of the inherent noise generated within semiconductor active devices, constituting the core of such systems. Examples of applications in which noise is a key issue include receiver front-ends in radiofrequency

  18. 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).

  19. Quantum transport and dielectric response of nanometer scale transistors using empirical pseudopotentials

    Science.gov (United States)

    Fang, Jingtian

    As transistors, the most basic component of central processing units (CPU) in all electronic products, are scaling down to the nanometer scale, quantum mechanical effects must be studied to investigate their performance. A formalism to treat quantum electronic transport at the nanometer scale based on empirical pseudopotentials is presented in this dissertation. We develop the transport equations and show the expressions to calculate the device characteristics, such as device current and charge density. We apply this formalism to study ballistic transport in a gate-all-around (GAA) silicon nanowire field-effect transistor (FET) with a body-size of 0.39 nm, a gate length of 6.52 nm, and an effective oxide thickness of 0.43 nm. Simulation results show that this device exhibits a subthreshold slope (SS) of ˜66 mV/decade and a drain-induced barrier-lowering of ~2.5 mV/V. This formalism is also applied to assess the ballistic performance of FETs with armchair-edge graphene nanoribbon (aGNRs) and silicon nanowire (SiNWs) channels and with gate lengths ranging from 5 nm to 15 nm. The device characteristics of the transistors with a 5 nm gate length are compared. Source-to-drain tunneling effects are investigated for SiNWFETs and GNRFETs by comparing the I-V characteristics of each respective transistor with different channel lengths. While a uniform dielectric constant is assumed in solving Poisson equation for the devices simulated above, the knowledge of the atomistic (i.e., local) dielectric permittivity that considers the atomistic electron distribution and quantum-confinement effect is necessary to treat the electrostatic properties accurately. The local permittivity can also provide information about the dielectric property at the interfaces. We use the random-phase approximation, first-order perturbation theory, and empirical pseudopotentials to calculate the static polarizability, susceptibility, and dielectric response function in graphene and GNRs. While the

  20. Jig protects transistors from heat while tinning leads

    Science.gov (United States)

    Pelletier, A. J.; Willis, G. A.

    1966-01-01

    In tinning transistor leads, an aluminum jig is used to dip the leads into the molten tin. The jigs mass shunts excess heat given off by the molten tin before it reaches and damages the transistor body.