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1

Metamorphic InP\\/InGaAs heterojunction bipolar transistors on GaAs substrate: DC and microwave performances  

Microsoft Academic Search

High-performance InP\\/In0.53Ga0.47As metamorphic heterojunction bipolar transistors (MHBTs) on GaAs substrate have been fabricated using InxGa1-xP strain relief buffer layer grown by solid-source molecular beam epitaxy (SSMBE). The MHBTs exhibited a dc current gain over 100, a unity current gain cutoff frequency (fT) of 48 GHz and a maximum oscillation frequency (fMAX) of 42 GHz with low junction leakage current and

Hong Wang; Geok Ing Ng; Haiqun Zheng; Hong Yang; Yongzhong Xiong; Subratra Halder; Kaihua Yuan; Chee Leong Tan; K. Rahdakrishnan; Soon Fatt Yoon

2001-01-01

2

A GaAs heterojunction bipolar transistor with 106 V breakdown  

SciTech Connect

A high voltage GaAs HBT with an open-base collector breakdown voltage of 106 V and an open-emitter breakdown voltage of 134 V has been demonstrated. A high quality 9.0 {micro}m thick collector doped to 2.0{times}10{sup 15} cm{sup {minus}3} grown by MBE on a doped GaAs substrate is the key to achieving this breakdown. These results were achieved for HBTs with 4{times}40 {micro}m{sup 2} emitters. DC current gain of 38 at 6,000 A/cm{sup 2} was measured.

Baca, A.G.; Klem, J.F.; Ashby, C.I.; Martin, D.C.

2000-01-11

3

Bipolar Junction Transistors  

NSDL National Science Digital Library

All About Circuits is a website that â??provides a series of online textbooks covering electricity and electronics.â? Written by Tony R. Kuphaldt, the textbooks available here are wonderful resources for students, teachers, and anyone who is interested in learning more about electronics. This specific section, Bipolar Junction Transistors, is the fourth chapter in Volume III â??Semiconductors. A few of the topics covered in this chapter include: The Transistor as a Switch, Active Mode Operation, and Input and Output Coupling. Diagrams and detailed descriptions of concepts are included throughout the chapter to provide users with a comprehensive lesson. Visitors to the site are also encouraged to discuss concepts and topics using the All About Circuits discussion forums (registration with the site is required to post materials).

Kuphaldt, Tony R.

4

Npn double heterostructure bipolar transistor with ingaasn base region  

DOEpatents

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.

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

2004-07-20

5

Super Matched Bipolar Transistor Pair Sets New  

E-print Network

Super Matched Bipolar Transistor Pair Sets New Standards for Drift and Noise Matched bipolar of the number of devices. The LM194 is the end result. It is a monolithic bipolar matched transistor pair which by a theoretical bipolar transistor model. The relationship between emitter-base voltage and collector cur- rent

Lanterman, Aaron

6

Noise Characterization for Heterojunction Bipolar Transistors (HBTs)  

Microsoft Academic Search

A commonly used noise model for the bipolar junction transistor is the one developed by Hawkin who derived BJT noise model for minimum noise figure (Fmin) by taking the emitter junction capacitance (CTe) into account and by neglecting the bias dependence of the different transistor parameters. Although such a noise model was developed for homojunction transistors, it has been frequently

Kuo-Wei Liu; A. F. M. Anwar

2004-01-01

7

Modeling Advanced Avalanche Effects for Bipolar Transistor Circuit Design  

E-print Network

Modeling Advanced Avalanche Effects for Bipolar Transistor Circuit Design Vladimir Milovanovi operating frequency and high output power of modern bipolar transistor circuits increase, designers are trying to exploit transistor operating regions where they would be able satisfy both conditions, namely

Technische Universiteit Delft

8

Vertical Bipolar Charge Plasma Transistor with Buried Metal Layer  

PubMed Central

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 · fT 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. PMID:25597295

Nadda, Kanika; Kumar, M. Jagadesh

2015-01-01

9

Vertical Bipolar Charge Plasma Transistor with Buried Metal Layer  

NASA Astrophysics Data System (ADS)

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 . fT 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.

Nadda, Kanika; Kumar, M. Jagadesh

2015-01-01

10

Vertical bipolar charge plasma transistor with buried metal layer.  

PubMed

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. PMID:25597295

Nadda, Kanika; Kumar, M Jagadesh

2015-01-01

11

Heterojunction bipolar transistors for millimeter waves applications: trends and achievements  

Microsoft Academic Search

\\u000a Abstract  This paper first presents the present status of heterojunction bipolar transistors (HBT) under development obtained using\\u000a either classical III-V based on GaAs or InP or SiGe compound semiconductors. Then a description of the developments to be\\u000a achieved to allowing the use of HBT up to millimeter wave is carried out. The description is focused on material and process\\u000a aspects. Afterwards

Sylvain L. Delage

2001-01-01

12

THz Bipolar Transistor Circuits: Technical Feasibility, Technology Development,  

E-print Network

THz Bipolar Transistor Circuits: Technical Feasibility, Technology Development, Integrated Circuit Scientific Abstract--We examine the feasibility of developing bipolar transistors with current-gain and power-frequency performance limits of InP-based bipolar transistors, and their potential for operation at low THz frequencies

Rodwell, Mark J. W.

13

Heterostructure bipolar transistors and integrated circuits  

Microsoft Academic Search

A bipolar transmitter with a wide-gap emitter is presented. Examples of heterostructure implementations of IIL and ECL are discussed, and future device possibilities based on technological premises are considered. The concept and high-speed benefits of the widegap emitter are reviewed, including recent conceptual developments such as an inverted transistor design in which the collector is made smaller than the emitter

HERBERT KROEMER

1982-01-01

14

Scaling of SiGe Heterojunction Bipolar Transistors  

E-print Network

Scaling of SiGe Heterojunction Bipolar Transistors JAE-SUNG RIEH, SENIOR MEMBER, IEEE, DAVID-century. This paper inves- tigates the impacts of scaling on SiGe heterojunction bipolar tran- sistors (HBTs), which and operation current density. Bipolar transistor scaling rules are reviewed and compared with accumulated

Rieh, Jae-Sung

15

Bipolar-FET combinational power transistors for power conversion applications  

NASA Technical Reports Server (NTRS)

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).

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

1984-01-01

16

Total Dose Effects in Conventional Bipolar Transistors  

NASA Technical Reports Server (NTRS)

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.

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

1994-01-01

17

Optical characterization of heterojunction bipolar transistors  

Microsoft Academic Search

We report the nondestructive, optical characterization of a heterojunction bipolar transistor (HBT) structure using photoreflectance spectroscopy (PR) and spectral ellipsometry (SE). The PR results show good agreement with capacitance-voltage (C-V) measurements for the dopant concentration in the n-GaAs collector layer. We find that PR provides a reasonable Nd for the emitter layer; whereas C-V analysis of the thin emitter layer

Patricia B. Smith; Walter M. Duncan; A. A. Allerman

1995-01-01

18

Electrothermal stability of bipolar transistors at medium-and high-current operation regimes  

E-print Network

Electrothermal stability of bipolar transistors at medium- and high-current operation regimes N Naples, Italy Abstract -- Electrothermal behavior of single- and two- finger bipolar transistors. Index Terms -- Bipolar devices, bipolar modeling and simulation, electrothermal behavior, electrothermal

Technische Universiteit Delft

19

Bipolar Spintronics: From magnetic diodes to magnetic bipolar transistors  

NASA Astrophysics Data System (ADS)

We develop a theory of bipolar (electrons and holes) spin-polarized transport [1,2] in semiconductors and discuss its implications for spintronic devices [3]. In our proposal for magnetic bipolar transistors [4,5] we show how bipolar spintronics can lead to spin and magnetic field controlled active devices, not limited by the magnetoresistive effects used in all-metallic structures [3]. We focus on magnetic p-n diodes [1,2] with spatially dependent spin splitting (Zeeman or exchange) of carrier bands. An exchange splitting can be provided by ferromagnetic semiconductors [6], while a large Zeeman splitting can be realized in the presence of magnetic field in magnetically doped or narrow band gap semiconductors [3]. Our theory of magnetic diodes [1,2] can be directly applied to magnetic bipolar transistors--the three-terminal devices which consist of two magnetic p-n diodes connected in series [4,5]. Predictions of exponentially large magnetoresistance [1] and a strong coupling between the spin and charge transport leading to the spin-voltaic effect [1,7] for magnetic diodes are also relevant for magnetic bipolar transistors. In particular, in n-p-n transistors, we show the importance of considering the nonequilibrium spin leading to the spin-voltaic effect. In addition to the applied magnetic filed, the injected nonequilibrium spin can be used to dynamically control the current amplification (gain). Recent experimental progress [8,9] supports the viability of our theoretical proposals. [1] I. Zutic, J. Fabian, S. Das Sarma, Phys. Rev. Lett. 88, 066603 (2002). [2] J. Fabian, I. Zutic, S. Das Sarma, Phys. Rev. B 66, 165301 (2002). [3] I. Zutic, J. Fabian, S. Das Sarma, Rev. Mod. Phys., in press. [4] J. Fabian, I. Zutic, S. Das Sarma, cond-mat/0211639; cond-mat/0307014, Appl. Phys. Lett., in press. [5] J. Fabian and I. Zutic, cond-mat/0311456. [6] H. Ohno, Science 281, 951 (1998). [7] I. Zutic, J. Fabian, S. Das Sarma, Appl. Phys. Lett. 82, 221 (2003). [8] N. Samarth, S. H. Chun, K. C. Ku, S. J. Potashnik, P. Schiffer, Solid State Commun. 127, 173 (2003). [9] F. Tsui, L. Ma, L. He, Appl. Phys. 83, 954 (2003).

Zutic, Igor

2004-03-01

20

Mathematical modeling of the characteristics of bipolar heterojunction transistors  

SciTech Connect

The authors review the known methods of modeling bipolar heterojunction transistors (BHT) and illustrate that none of the available models is sufficiently universal. The authors develop a semi-empirical model which is valid for a wide number of heterojunctions, such as InSb-Ge, GaSb-Ge, CdS-Ge, GaAs-Ge, ZnSe-Ge, GaAs-Si, ZnSe-GaAs, etc., plus three-component compounds such as Als/bu z/Ga/sub 1-z/ As - GaAs. The assumptions underlying the model were confirmed experimentally in the cases when the heterojunction is formed by compounds of the group A/sub III/B/sub V/ with a common anion, such as CdTe-CdHgTe.

Butakova, N.G.; Valiev, K.A.; Zubov, A.V.; Orlikovskii, A.A.

1986-03-01

21

A HIGH VOLTAGE GaAs STATIC INDUCTION TRANSISTOR  

Microsoft Academic Search

Design, fabrication and pulsed switching characteristics of a high voltage GaAs static induction transistor (SIT) are reported. The SIT is a vertical channel field-effect transistor which exhibits intrinsic turn-on and turn-off capability. In the GaAs SIT, optoelectronic modulation allows for isolation of the signal source and the high side switch, which in turn results in improved reliability in high voltage,

P. Hadizad; J. H. Hur; H. Zhao; K. Kaviani; M. A. Gundersen; H. R. Fetterman

1992-01-01

22

Perpendicular transport in superlattice bipolar transistors (SBT)  

NASA Astrophysics Data System (ADS)

Diffusion-limited electron transport in superlattices is studied by gain measurements on heterojunction bipolar transistors with a {GaAs}/{GaAlAs} superlattice base. In the case of thin barriers, Bloch conduction is observed, while hopping between localized levels prevails for large barriers. A transition occurs between these two regimes, localization being achieved when the energy broadening induced by the electron-phonon coupling added to the disorder due to imperfect growth is of the order of the miniband width. This interpretation is supported by temperature dependence measurements of the perpendicular mobilities in relation with theoretical calculations of these mobilities.

Sibille, A.; Palmier, J. F.; Minot, C.; Harmand, J. C.; Dubon-Chevallier, C.

23

Review of Heterojunctin Bipolar Transistor Structure, Applications, and Reliability  

NASA Technical Reports Server (NTRS)

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.

Lee, C.; Kayali, S.

1993-01-01

24

Transmission resonances in the bipolar quantum resonant tunneling transistor  

E-print Network

,rabolic dispersion relation. Calculations are done for model cases and compared to analytical results. The original and generalized methods are then applied to real world device potential profiles. In particular, the bipolar quantum resonant tunneling transistor (Bi...

Mondragon, Antonio Richard

1996-01-01

25

3.0 Bipolar Junction Transistors 1 of 18 3.1 Introduction  

E-print Network

3.0 Bipolar Junction Transistors 1 of 18 3.1 Introduction 3.2 Transistor Construction 3 it and are swept across. #12;3.0 Bipolar Junction Transistors 2 of 18 3.4 Common-Base Configuration Notation-biased Collector-Emitter junction is reverse- biased #12;3.0 Bipolar Junction Transistors 3 of 18 Input or driving

Allen, Gale

26

RF SMALL SIGNAL AVALANCHE CHARACTERIZATION AND REPERCUSSIONS ON BIPOLAR TRANSISTOR CIRCUIT DESIGN  

E-print Network

RF SMALL SIGNAL AVALANCHE CHARACTERIZATION AND REPERCUSSIONS ON BIPOLAR TRANSISTOR CIRCUIT DESIGN transistor circuits, electronic circuit designers are exploring regimes of transistor operation that meet on some important transistor properties like unilateral and maximum available power gain, as well

Technische Universiteit Delft

27

CVD Synthesis of Graphene and Graphene Bipolar Junction Transistor  

NASA Astrophysics Data System (ADS)

CVD is a technology for massive production of graphene. In this dissertation, CVD growth of graphene and graphene transfer are presented. Graphene growth typically takes place with catalysts such as Ni and Cu. The growth mechanisms are different with the two catalysts. The synthesized graphene is used in a new transistor, graphene-based bipolar junction transistor. It has the same functionality as a Si-based bipolar junction transistor, but with a totally different operation mechanism. The electron transportation across graphene takes a key role. The current gain beta = IC/IB is measured to be up to 10.

Miao, Congqin

28

Advanced insulated gate bipolar transistor gate drive  

DOEpatents

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.

Short, James Evans (Monongahela, PA); West, Shawn Michael (West Mifflin, PA); Fabean, Robert J. (Donora, PA)

2009-08-04

29

An NMOS input merged bipolar/sidewall-MOS transistor with a bypass sidewall MOS transistor (NBiBMOS transistor)  

NASA Astrophysics Data System (ADS)

A combined transistor structure is described with specific attention given to the device characteristics. Called an NBiBMOS transistor, the concept is based on the merging of a vertical n-p-n bipolar and two sidewall NMOS transitors into an NMOS input merged bipolar/sidewall-MOS transistor with a bypass sidewall NMOS transistor structure. NBiBMOS transistors are fabricated which have areas about 1.2 times those of single n-p-n transistors. The devices are tested and shown to have higher current drive capabilities than structures based on an NBiMOS and a separate NMOS bypass transistor. The body-source junction of the bypass NMOS transistor is forward-biased in the NBiBMOS structure, giving it the good current-drive characteristics.

Kenneth, K. O.; Lutsky, Joseph J.; Reif, Rafael L.; Lee, Hae-Seung

1992-11-01

30

Free electron gas primary thermometer: The bipolar junction transistor  

SciTech Connect

The temperature of a bipolar transistor is extracted probing its carrier energy distribution through its collector current, obtained under appropriate polarization conditions, following a rigorous mathematical method. The obtained temperature is independent of the transistor physical properties as current gain, structure (Homo-junction or hetero-junction), and geometrical parameters, resulting to be a primary thermometer. This proposition has been tested using off the shelf silicon transistors at thermal equilibrium with water at its triple point, the transistor temperature values obtained involve an uncertainty of a few milli-Kelvin. This proposition has been successfully tested in the temperature range of 77–450?K.

Mimila-Arroyo, J., E-mail: jmimila@cinvestav.mx [Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Dpto. de Ing. Eléctrica-SEES, Av. Instituto Politécnico Nacional No 2508, México D.F. CP 07360 (Mexico)

2013-11-04

31

Experimental demonstration of a magnetic bipolar junction transistor E. Johnston-Halperin*a  

E-print Network

Experimental demonstration of a magnetic bipolar junction transistor E. Johnston-Halperin*a , M. E of a magnetic base layer to a bipolar junction transistor has the potential to serve as an exceptionally-doped (Ga,Mn)As layer into the p region of an n-p-n III-As heterojunction bipolar transistor. These proof

Flatte, Michael E.

32

Impact of emitter resistance mismatch on base and collector current matching in bipolar transistors  

E-print Network

Impact of emitter resistance mismatch on base and collector current matching in bipolar transistors rue des Martyrs, 38016 Grenoble, France ABSTRACT Bipolar transistor matching is characterized the bipolar transistor matching in medium and high current zones. We demonstrate the preponderant impact

McNeill, John A.

33

IEEE BCTM 2.1 On the Feasibility of few-THz Bipolar Transistors  

E-print Network

IEEE BCTM 2.1 On the Feasibility of few-THz Bipolar Transistors Mark Rodwell, E. Lind, Z. Griffith the limits faced in scaling of InP-based bipolar transistors for increased device bandwidth. Emitter and baseGe technologies. 250 nm Indium Phosphide (InP) heterojunction bipolar transistors (HBTs) have demonstrated 416 GHz

Rodwell, Mark J. W.

34

RF Model of Lateral Bipolar Junction Transistor on Silicon-on-Insulator Substrate  

E-print Network

RF Model of Lateral Bipolar Junction Transistor on Silicon-on-Insulator Substrate Dora Lee and I-Shan Michael Sun and Wai Tung Ng Abstract- A methodology for modelling a novel high- frequency lateral bipolar] in the lateral bipolar transistor (LBJT) indicate that there is a drive to better integrate bipolar devices

Ng, Wai Tung

35

The SIT saturation protected bipolar transistor  

Microsoft Academic Search

A novel transistor fabrication concept for saturating logic gate arrays is proposed. The idea involves using a static induction transistor (SIT) to protect against saturation. Current simulation tests show encouraging switching times for the saturation-protected transistor gates when compared to similar gates without protection by a SIT. The collector charge-storage effect was practically eliminated.

B. M. Wilamowski; R. H. Mattson; Z. J. Staszak

1984-01-01

36

Heterojunction bipolar transistor technology for data acquisition and communication  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

37

Proton and gamma ray induced gain degradation in bipolar transistor  

NASA Astrophysics Data System (ADS)

This paper describes the results of the effect of 24 MeV proton and (CO)-C-60 gamma-irradiation on the collector characteristic., and forward current gain of commercial bipolar transistor (npn 2N2219A). The transistor has been exposed to these radiations in the biased condition and the collector characteristics and forward current gain have been measured as a function of proton fluence and gamma-dose. The observation is that both the proton and gamma-irradiation induce significant gain degradation in the transistor. The results are discussed in terms of displacement damage produced by energetic protons and gamma-radiation in the bulk of the semiconductor.

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

2003-09-01

38

Experiments with Charge Indicator Based on Bipolar Transistors  

ERIC Educational Resources Information Center

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…

Dvorak, Leos; Planinsic, Gorazd

2012-01-01

39

Demonstration and properties of a planar heterojunction bipolar transistor with lateral current flow  

NASA Astrophysics Data System (ADS)

The authors present fabrication techniques and device performance for a novel transistor structure, the lateral heterojunction bipolar transistor. The lateral heterojunctions are formed by impurity-induced disordering of a GaAs base layer sandwiched between two AlGaAs layers. These transistor structures exhibit current gains of 14 for base widths of 0.74 micron. Transistor action in this device occurs parallel to the surface of the device structure. The active base region of the structure is completely submerged, resulting in a reduction of surface recombination as a mechanism for gain reduction in the device. Impurity-induced disordering is used to widen the bandgap of the alloy in the emitter and collector, resulting in an improvement of the emitter injection efficiency. Since the device is based entirely on a surface diffusion process, the device is completely planar and has no steps involving etching of the III-V alloy material. These advantages lead this device to be considered as a candidate for optoelectronic integration applications. The transistor device functions as a buried heterostructure laser, with a threshold current as low as 6 mA for a 1.4-micron stripe.

Thornton, Robert L.; Mosby, William J.; Chung, Harlan F.

1989-10-01

40

The SIT Saturation protected bipolar transistor  

Microsoft Academic Search

A novel concept for a transistor was invented, introducing an idea for protection against saturation. It involves the use of a static induction transistor (SIT). Simulation showed encouraging switching times when compared to similar gates without protection, while the charge storage was practically eliminated.

B. M. Wilamowski; R. H. Mattson; Z. J. Staszak

1984-01-01

41

Development of a RF Bipolar Transistor in a Standard 0.35m CMOS Technology  

E-print Network

Development of a RF Bipolar Transistor in a Standard 0.35µm CMOS Technology I-Shan Michael Sun-0021, Japan ABSTRACT A RF Bipolar Transistor integrated to a standard 0.35µm CMOS process is presented compared to previously published BiCMOS technologies. Key Words 0.35µm CMOS Technology, RF Silicon Bipolar

Ng, Wai Tung

42

IEEE TRANSACTIONS ON ELECTRON DEVICES 1 Bipolar Charge-Plasma Transistor  

E-print Network

IEEEProof IEEE TRANSACTIONS ON ELECTRON DEVICES 1 Bipolar Charge-Plasma Transistor: A Novel Three approach for forming a lateral bipolar4 charge-plasma transistor (BCPT) is explored using 2-D simu-5-p-n transistor. Electrical characteristics of the proposed9 device are simulated and compared

Kumar, M. Jagadesh

43

InP/In0.53Ga0.47As/InP Double Heterojunction Bipolar Transistors on a GaAs Substrate Using InP Metamorphic Buffer Layer  

E-print Network

P Metamorphic Buffer Layer Y.M. Kim, M. Dahlstrom, S. Lee, M.J.W. Rodwell, A.C. Gossard Double heterojunction metamorphic growth of InP-based DHBTs on GaAs substrates [4]. Here we report InP-based DHBTs grown on GaAs using InP as the metamorphic buffer layer. While AlGaAsSb and InAlAs have been explored

Rodwell, Mark J. W.

44

Doping To Reduce Base Resistances Of Bipolar Transistors  

NASA Technical Reports Server (NTRS)

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.

Lin, True-Lon

1991-01-01

45

InP Heterojunction Bipolar Transistor Amplifiers to 255 GHz  

NASA Technical Reports Server (NTRS)

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.

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

2009-01-01

46

Bipolar transistor scaling for minimum switching delay and energy dissipation  

Microsoft Academic Search

A novel figure-of-merit to guide in the scaling of high-speed bipolar transistors is proposed. A method is described to relate the gate delay of a ring-oscillator to measurable device parameters analytically. The closed-form solution for an unloaded ECL (emitter coupled logic) gate agrees very well with published data of the past several years and with the results of circuit simulation.

J. M. C. Stork

1988-01-01

47

Investigation of the tunneling emitter bipolar transistor as spin-injector into silicon  

E-print Network

In this thesis is discussed the tunneling emitter bipolar transistor as a possible spin-injector into silicon. The transistor has a metallic emitter which as a spin-injector will be a ferromagnet. Spin-polarized electrons ...

Van Veenhuizen, Marc Julien

2010-01-01

48

A review of radiation effects in heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

We present a review of radiation effects studies on heterojunction bipolar transistors (HBTs) in order to develop a framework for qualifying devices for application in the harsh radiation environment of space. Radiation effects in different HBT material systems are considered here, including Si/SiGe, GaAs/AlGaAs, and InP/InGaAs. We discuss the different effects of ionizing and nonionizing radiation on device performance and review the strong role that device geometry plays in determining the overall radiation tolerance. We present a new comparison of radiation tolerance in conventional transistors, HBTs, and high electron mobility transistors. Finally, we conclude that with proper design, HBTs are excellent candidates for application in space.

Weaver, B. D.

2005-09-01

49

A comparison between bipolar transistor and nanowire field effect transistor biosensors  

NASA Astrophysics Data System (ADS)

Important performance metrics, such as sensitivity and signal to noise ratio (SNR) of bipolar transistor based biosensors, are compared to those for nanowire field effect transistor (FET) sensors. The sensor consists of a heterojunction bipolar transistor (HBT) with silicon germanium base connected to a sensing surface in contact with the solution. The measured sensitivity is ?2 times and SNR is >20 times higher in comparison to those for nanowire FET sensors. More importantly, the HBT biosensor sensitivity is constant over the sensing range of ˜5 decades and depends only on the temperature. In comparison, the nanowire FET sensor sensitivity varies in a complex manner over the sensing range and exhibits significant fabrication induced sensor to sensor variations. Consequently, HBT sensors would require minimal calibration for quantitative sensing studies. Furthermore, the bipolar transistor SNR is not only significantly higher but is also constant over the sensing range. In comparison, the nanowire FET sensor SNR varies with the peak value confined over a narrow sensing range. Hence, HBT sensor has <20 times lower detection limit that remains constant over the sensing range. In summary, HBT sensors are demonstrated to have superior performance metrics and are better suited for quantitative studies. Lastly, these HBT sensors also provide simultaneous temperature measurement.

Zafar, Sufi; Khater, Marwan; Jain, Vibhor; Ning, Tak

2015-02-01

50

Experimental research on the damage effect of HPM on semiconductor bipolar transistor  

Microsoft Academic Search

High power microwave (HPW) can cause the semiconductor devices failure,thereby make the electronic system work anomaly. Bipolar transistors are the typical semiconductor devices. In this paper, the effect of HPM on the bipolar transistors is studied through the HPM injection experiment. The experiment results show that the HPM injected into the devices could cause the degradation, distortion and damage of

Hailong You; Juping Fan; Xinzhang Jia; Ling Zhang

2010-01-01

51

A New SiGe Base Lateral PNM Schottky Collector Bipolar Transistor on SOI for Non-Saturating  

E-print Network

A New SiGe Base Lateral PNM Schottky Collector Bipolar Transistor on SOI for Non-Saturating VLSI Logic Design Abstract- A novel bipolar transistor structure, namely, SiGe base lateral PNM Schottky collector bipolar transistor (SCBT) in Silicon-On-Insulator (SOI) substrate is explored using two

Kumar, M. Jagadesh

52

Proposal and design of a new SiC-emitter lateral NPM Schottky collector bipolar transistor on  

E-print Network

Proposal and design of a new SiC-emitter lateral NPM Schottky collector bipolar transistor on SOI for VLSI applications M. Jagadesh Kumar and D.V. Rao Abstract: A novel bipolar transistor structure, namely, a SiC emitter lateral NPM Schottky collector bipolar transistor (SCBT) with a silicon-on-insulator (SOI

Kumar, M. Jagadesh

53

The equivalence of displacement damage in silicon bipolar junction transistors  

NASA Astrophysics Data System (ADS)

The current gain degradation in silicon bipolar junction transistors (BJTs) is examined under the irradiation with heavy ions. To characterize the radiation damage of the BJTs, the ionizing dose Di and displacement dose Dd verse the chip depth in the BJTs have been calculated for heavy ions. Based on the irradiation testing and calculation results, an approach to evaluate the equivalence of displacement damage in silicon BJTs is given, which could optimize the non-ionizing energy loss (NIEL) methodology and normalize the displacement damage caused by heavy ions.

Liu, Chaoming; Li, Xingji; Geng, Hongbin; Rui, Erming; Guo, Lixin; Yang, Jianqun; Xiao, Liyi

2012-06-01

54

IEEE BCTM 12.3 Distribution ofthe Collector Resistance ofPlanar Bipolar Transistors  

E-print Network

IEEE BCTM 12.3 Distribution ofthe Collector Resistance ofPlanar Bipolar Transistors: Impact Abstract We investigate the relevance ofthe distribution ofthe extrinsic collector resistance of a bipolar results are relevant to compact modeling, bipolar device technology de- velopment and characterization

Technische Universiteit Delft

55

1070 IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 49, NO. 6, JUNE 2002 A New Lateral PNM Schottky Collector Bipolar Transistor  

E-print Network

Collector Bipolar Transistor (SCBT) on SOI for Nonsaturating VLSI Logic Design M. Jagadesh Kumar and D. Venkatesh Rao Abstract--The novel characteristics of a new lateral PNM Schottky col- lector bipolar suggested providing the incentive for experimental verification. Index Terms--Bipolar transistor, lateral

Kumar, M. Jagadesh

56

1376 IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 52, NO. 7, JULY 2005 Lateral High-Speed Bipolar Transistors  

E-print Network

1376 IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 52, NO. 7, JULY 2005 Lateral High-Speed Bipolar--This paper introduces a novel silicon-on-insulator (SOI) lateral radio-frequency (RF) bipolar transistor for lateral bipolar junction transistors (LBJT) so far. As for the high-voltage device, the measured max of 12

Ng, Wai Tung

57

The impact of non-equilibrium transport on breakdown and transit time in bipolar transistors  

Microsoft Academic Search

Impact ionization and velocity overshoot in the base-collector junction of bipolar transistors are studied using Monte Carlo simulation and the hydrodynamic energy-balance equation. For advanced bipolar transistors, the carrier energy lags the electric field; therefore, the maximum impact ionization rate occurs deep into the junction. A simplified solution of the energy-balance equation can accurately model this nonlocal behavior. Excellent agreement

E. F. Crabbe; J. M. C. Stork; G. Baccarani; M. V. Fischetti; S. E. Laux

1990-01-01

58

Total dose effects in conventional bipolar transistors and linear integrated circuits  

Microsoft Academic Search

Total dose damage is investigated for discrete bipolar transistors and linear integrated circuits that are fabricated with older processing technologies, but are frequently used in space applications. The Kirk effect limits the current density of discrete transistors with high collector breakdown voltage, increasing their sensitivity to ionizing radiation because they must operate low injection levels. Bias conditions during irradiation had

A. H. Johnston; G. M. Swift; B. G. Rax

1994-01-01

59

Evaluation of temperature-enhanced gain degradation of verticle npn and lateral pnp bipolar transistors  

SciTech Connect

The effect of dose rate on radiation-induced gain degradation is compared for verticle npn and lateral pnp bipolar transistors. High dose rate irradiations at elevated temperatures are more effective at simulating low dose rate degradation in the lateral pnp transistors.

Witczak, S.C.; Lacoe, R.C. [Aerospace Corp., Los Angeles, CA (United States). Electronics Technology Center; Galloway, K.F. [Vanderbilt Univ., Nashville, TN (United States). Dept. of Electrical and Computer Engineering] [and others

1997-03-01

60

Silicon-germanium base heterojunction bipolar transistors by molecular beam epitaxy  

Microsoft Academic Search

We report the first SiGe base heterojunction Bipolar Transistors (HBT) The devices were fabricated using Molecular Beam Epitaxy (MBE), low temperature processing and different germanium contents. The transistors demonstrate current gain and show the expected increase in collector current as a result of reduced bandgap due to Ge incorporation in the base. A 6 times increase in collector current was

S. S. Iyer; G. L. Patton; S. S. Delage; S. Tiwari; J. M. C. Stork

1987-01-01

61

Inversion-mode GaAs wave-shaped field-effect transistor on GaAs (100) substrate  

NASA Astrophysics Data System (ADS)

Inversion-mode GaAs wave-shaped metal-oxide-semiconductor field-effect transistors (WaveFETs) are demonstrated using atomic-layer epitaxy of La2O3 as gate dielectric on (111)A nano-facets formed on a GaAs (100) substrate. The wave-shaped nano-facets, which are desirable for the device on-state and off-state performance, are realized by lithographic patterning and anisotropic wet etching with optimized geometry. A well-behaved 1 ?m gate length GaAs WaveFET shows a maximum drain current of 64 mA/mm, a subthreshold swing of 135 mV/dec, and an ION/IOFF ratio of greater than 107.

Zhang, Jingyun; Lou, Xiabing; Si, Mengwei; Wu, Heng; Shao, Jiayi; Manfra, Michael J.; Gordon, Roy G.; Ye, Peide D.

2015-02-01

62

Trends in the total-dose response of modern bipolar transistors  

Microsoft Academic Search

The various phenomena occurring in bipolar transistors when they are exposed to ionizing radiation are discussed. NPN transistors are found to degrade more than PNP transistors. Devices with highly doped base rings will be less susceptible to total-dose damage than devices without base rings, especially in NPN devices. Devices with small emitter perimeter-to-area ratios will be less susceptible than devices

R. N. Nowlin; E. W. Enlow; R. D. Schrimpf; W. E. Combs

1992-01-01

63

IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 48, NO. 11, NOVEMBER 2001 2455 Bipolar Transistor Technology: Past and Future  

E-print Network

IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 48, NO. 11, NOVEMBER 2001 2455 Bipolar Transistor transistor. The emergence of the transistor from Bell Laboratories in late 1947 and early 1948 was the first step in the development of today's semiconductor electronics industry. Currently transistor production

Rodwell, Mark J. W.

64

Bendable GaAs metal-semiconductor field-effect transistors formed with printed GaAs wire arrays on plastic substrates  

E-print Network

of these wires at low temperatures onto plastic substrates yield high-quality bendable metal-semiconductor fieldBendable GaAs metal-semiconductor field-effect transistors formed with printed GaAs wire arrays on plastic substrates Yugang Sun, Seiyon Kim, Ilesanmi Adesida, and John A. Rogersa University of Illinois

Rogers, John A.

65

A bipolar mechanism for alpha-particle-induced soft errors in GaAs integrated circuits  

Microsoft Academic Search

The alpha-particle-induced collected charge in undoped LEC semi-insulating GaAs is measured in n+-i-n+ and n+-p-n+ isolation structures and is compared with the results of an analytical model based on a bipolar mechnism. In n+-i-n+ isolation structures, a collected-storage multiplication phenomenon induced by alpha-particle incidence is observed. The measured collected charge is about three times the alpha-particle-generated charge. This phenomenon can

Yasunari Umemoto; Nobutoshi Matsunaga; Kazumichi Mitsusada

1989-01-01

66

Bipolar-Field-Effect-Transistor Hybrid-Mode Operation of Lateral Silicon-on-Insulator Bipolar Mode Field Effect Transistor with Improved Current Gain  

NASA Astrophysics Data System (ADS)

A hybrid-mode operation of silicon-on-insulator (SOI) bipolar mode field effect transistor (BMFET) is proposed to improve the current gain. The device characteristics are analyzed and verified numerically for hybrid mode, BMFET mode, and double-diffused metal-oxide-semiconductor field effect transistor (DMOS) mode by MEDICI simulation. In hybrid-mode operation, DMOS, lateral bipolar transistor, and BMFET currents flow simultaneously. The proposed SOI BMFET exhibits 30 times larger current gain in hybrid mode operation by connecting DMOS gate to the p+ gate of BMFET structure as compared with the conventional structure without sacrifice of breakdown voltage and leakage current characteristics. The improved current gain characteristics are achieved by the DMOS-gate-induced hybrid effect that lowers the barrier of p-body and reduces the charge in the p-body.

Kim, Doo-Young; Kim, Seong-Dong; Han, Min-Koo; Choi, Yearn-Ik

1998-04-01

67

Design and fabrication of gallium nitride-based heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

A self-aligned fabrication process for small and large emitter contact area (2 x 4 mum2 and 1.96 x 103 mum 2 respectively) GaN-based heterojunction bipolar transistor and bipolar junction transistors is proposed. The process features dielectric-spacer sidewalls, low-damage dry etching and selected-area regrowth of GaAs(C) on the base contact, and self-aligned emitter base regrowth processes are provided. The junction current-voltage (I--V) characteristics were evaluated at various stages of the process sequence and provided an excellent diagnostic for monitoring the effect of plasma processes such as CVD or etching. A comparison is given with large emitter-area devices fabricated on the same material. The small-area devices are attractive for microwave power switching applications, provided that a high-yield process can be developed. Series resistance effects are still found to influence device performance. In the dc performance of small and large emitter contact area GaN-based heterojunction bipolar transistors, the do current gain of both types of device improves with temperature, which we ascribe to higher ionization efficiency of the Mg acceptor in the p-base region. The presence of a resistive base layer at room temperature forces base current to flow directly to the collector, reducing the current gain. However, to date, all of the reported GaN-based heterojunction bipolar transistors (HBTs) and bipolar junction transistors (BJTs) have had lots of problems to be solved even if there are many advantages to this technology. To predict the performance of GaN-based HBTs and BJTs, we simulated these structures with 2-dimensional device simulators. The effects of base doping and thickness on do current gain, collector-emitter saturation voltage, saturation current, collector-emitter breakdown voltage, rf characteristics (fT) and the effects of impurity ionization as a function of device operation temperature of GaN, AlGaN, InGaN-based heterojunction bipolar transistors, and junction bipolar transistors were investigated using a drift-diffusion transport model. Different base layer designs (including superlattice bases) for GaN-based heterojunction bipolar transistors (HBTs) and BJTs were simulated with MEDICI code. Given the low ionization efficiency of Mg acceptors in the base, it is important to design structures that avoid depletion of the base layer. The presence of a resistive base causes current to flow directly to the collector, severely reducing gain. The temperature effects of GaN-based heterojunction bipolar transistors were investigated by simulations. The contact resistances are all significantly decreased at high temperatures, where ionization efficiency is maximized.

Lee, Kyu-Pil

68

\\\\Proc. IEEE 2004 Int. Conference on MicroelectronicTest Structures, Vol 17, March 2004. 127 A New Test Circuit for the Matching Characterization of npn Bipolar Transistors  

E-print Network

.3 A New Test Circuit for the Matching Characterization of npn Bipolar Transistors Jan Einfeld", Ulrich is presented for the mismatch characterization of npn bipolar transistors. The macro contains a CMOS circuit which serves for the selection of each bipolar device individually. For each bipolar device terminal

McNeill, John A.

69

Graded-SiGe-base, poly-emitter heterojunction bipolar transistors  

Microsoft Academic Search

Si\\/Si1-xGex heterojunction bipolar transistors (HBTs) fabricated using a low-temperature epitaxial technique to form the SiGe graded-bandgap base layer are discussed. These devices were fabricated on patterned substrates and subjected to annealing cycles used in advanced bipolar processing. These devices, which have base widths under 75 mm, were found to have excellent junction qualities. Due to the small bandgap of SiGe,

G. L. Patton; D. L. Harame; J. M. C. Stork; B. S. Meyerson; G. J. Scilla; E. Ganin

1989-01-01

70

Current gain rolloff in graded-base SiGe heterojunction bipolar transistors  

SciTech Connect

The authors report the experimental observation of a novel effect in SiGe heterojunction bipolar transistors (HBT's) with graded bases which results in a significant emitter-base bias dependence of the current gain. The nonideal collector current is caused by the interaction of the bias dependence of the emitter-base space-charge region width and the exponential dependence of the collector current on the germanium concentration at the edge of the space-charge region. The resulting current gain rolloff must be taken into account for accurate modeling of bipolar transistors with bandgap grading in the base.

Crabbe, E.F.; Cressler, J.D.; Patton, G.L.; Stork, J.M.C.; Comfort, J.H.; Sun, J.Y.C. (Thomas J. Watson Research Center, Yorktown Heights, NY (United States))

1993-04-01

71

The insulated gate transistor - A new three-terminal MOS-controlled bipolar power device  

NASA Astrophysics Data System (ADS)

A new three-terminal power device, called the insulated gate transistor (IGT), with voltage-controlled output characteristics is described. In this device, the best features of the existing families of bipolar devices and power MOSFETs are combined to achieve optimal device characteristics for low-frequency power-control applications. Devices with 600-V blocking capability fabricated using a vertical DMOS process exhibit 20 times the conduction current density of an equivalent power MOSFET and five times that of an equivalent bipolar transistor operating at a current gain of 10. Typical gate turn-off times have been measured to range from 10 to 50 microseconds.

Baliga, B. J.; Adler, M. S.; Love, R. P.; Gray, P. V.; Zommer, N. D.

1985-06-01

72

Ballistic and tunneling GaAs static induction transistors: nano-devices for THz electronics  

Microsoft Academic Search

GaAs static induction transistors (SIT) with 10-nm scale channel and with a 100-nm channel were fabricated with molecular layer epitaxy (MLE). Area-selective epitaxy of GaAs\\/AlGaAs\\/GaAs was used for the gate. Temperature dependence of current-voltage (I-V) characteristics of the 100-nm SIT indicates ballistic injection of electrons. In the 10-nm scale SIT, electrons are transported ballistically in the drain-side electric field. Direct

Jun-ichi Nishizawa; P. Plotka; T. Kurabayashi

2002-01-01

73

High Power X-Band GaAs Field Effect Transistors  

Microsoft Academic Search

Design considerations and processing techniques related to high power X-band GaAs field effect transistors will be presented. Particular emphasis will be placed on the problems associated with common lead inductance, gate-drain breakdown voltage and thermal resistance. The microwave performance of large periphery designs (up to 10 mms) will be reported. The superior performance of via-hole source connected devices with integral

B. S. Hewitt; R. C. Ellis; R. P. Thomas; R. M. Healy; M. Benedek

1979-01-01

74

A high-voltage optoelectronic GaAs static induction transistor  

Microsoft Academic Search

Experimental realization of an optically activated, high-voltage GaAs static induction transistor (SIT) is reported. In the forward blocking state, the breakdown voltage of the device was ~200 V, while in the conduction state, on-state current densities exceeding 150 A\\/cm2 were obtained. In the floating-gate configurations (gate open), the specific on-resistance of the device was ~50 m?-cm2. Optical modulation of the

P. Hadizad; J. H. Hur; H. Zhao; K. Kaviani; Martin A. Gundersen; Harold R. Fetterman

1993-01-01

75

Base-contact proximity effects in bipolar transistors with nitride-spacer technology  

E-print Network

Base-contact proximity effects in bipolar transistors with nitride-spacer technology Henk van Zeijl-BJT's with spacer separated Al/Si emitter and base contacts are fabricated and characterized. Due to the proximity of the base contact to the emitter-base junction, the base current is increased by two peripheral effects

Technische Universiteit Delft

76

Analytical Model for Collector Current Gummel Plots of Heterojunction Bipolar Transistors  

Microsoft Academic Search

The work develops an analytical model for HBT's Gummel plots, based on thermionic-field-emission theory. This new model is easier to apply for usual HBT's Gummel characterization. Its validity was demonstrated by analysis of the experimental results of silicon nitride passivated InP\\/InGaAs heterojunction bipolar transistors.

D. Sachelarie; G. Predusca

2009-01-01

77

Enhanced SiGe heterojunction bipolar transistors with 160 GHz-fmax  

Microsoft Academic Search

Double-mesa type SiGe heterojunction bipolar transistors (HBTs) have been improved by increasing the base Gummel number and by using a thin, highly doped launcher layer between the base and the collector. In addition, the contact resistance of the base contact has been reduced. Hence, it was possible to obtain a record maximum frequency of oscillation up to 160 GHz for

A. Schuppen; U. Erben; A. Gruhle; H. Kibbel; H. Schumacher; U. Konig

1995-01-01

78

Current gain collapse in microwave multifinger heterojunction bipolar transistors operated at very high power densities  

Microsoft Academic Search

The rapid development of heterojunction bipolar transistor (HBT) technologies has led to the demonstration of high power single-chip microwave amplifiers. Because HBTs are operated at high power densities, the ultimate limits on the performance of HBTs are imposed by thermal considerations. The authors address a thermal phenomenon observed when a multifinger power HBT is operating at high power densities. This

William Liu; Steve Nelson; Darrell G. Hill; Ali Khatibzadeh

1993-01-01

79

An ultrasonic-switching three phase current source inverter with insulated gate bipolar transistors  

Microsoft Academic Search

Insulated Gate Bipolar Transistor (IGBT) were applied in ultrasonic switching current source inverters for power purposes. The current source inverter is supplied by a current mode controlled chopper. Both parts, the inverter as well as the chopper consist of IGBT which enable the use of a 20 kHz switching frequency. The current source inverter is controlled by using a periodic

A. C. Blom

1989-01-01

80

SiGe-base heterojunction bipolar transistors: physics and design issues  

Microsoft Academic Search

It has been shown that SiGe technology has the capability to extend the performance of Si bipolar transistors at both high and low current levels. The ability to tailor the bandgap, independently of the doping profile design, provides considerable flexibility for optimizing cutoff frequency, intrinsic base resistance, and junction capacitances for a given application. It is concluded that, when combined

G. L. Patton; J. M. C. Stork; J. H. Comfort; E. F. Crabbe; B. S. Meyerson; D. L. Harame; J. Y.-C. Sun

1990-01-01

81

Le transistor effet de champ grille Schottky au GaAs : analyse et modle mathmatique du fonctionnement  

E-print Network

303 Le transistor à effet de champ à grille Schottky au GaAs : analyse et modèle mathématique du théorique et expérimentale, en régime statique, du comportement du transistor à effet de champ à l du transistor, lorsque la grille est distribuée suivant la longueur L de grille, est établi et permet

Paris-Sud XI, Université de

82

The Low-Temperature Static and Dynamic Properties of High-Performance Silicon Bipolar Transistors  

NASA Astrophysics Data System (ADS)

The first comprehensive investigation of the low temperature static and dynamic properties of high-performance silicon bipolar transistors is presented. The major conclusion of this research is that contrary to popular belief, conventionally designed silicon bipolar transistors undergo comparatively minor current gain degradation and are capable of extremely fast switching speeds when cooled to liquid nitrogen temperature (77 K). Thus, this work suggests that silicon bipolar transistors are potentially attractive candidates for future low temperature computer system applications. Transistors were fabricated with 1.2 ?m optical lithography using a state of the art, double-polysilicon, self-aligned structure. Minimum geometry devices have near-ideal DC characteristics at low temperatures with current gain as high as 80 at 77 K without intentional profile modification. The transistor cutoff frequency is as high as 10 GHz and ECL circuits switch at sub-200 pS speeds at 85 K. Measurements of the current dependence of the transistor gain as a function of temperature suggest that an effect best described as "injection induced bandgap narrowing" plays an important role in determining the low temperature properties of bipolar transistors. This high current effect produces a significant enhancement in the current gain at low temperatures which is unaccounted for in conventional bipolar device theory. A simple phenomenological model which gives good agreement with data is presented. Detailed base current measurements as a function of temperature were used to examine the physics of hole injection in polysilicon emitter contacts. The results are consistent with the recently proposed thermionic-diffusion model and suggest that a thermal barrier exists at the polysilicon-single crystal silicon interface. Two dimensional simulations were used to investigate the various low temperature profile design strategies. Results suggest that a "relaxed scale" approach based on the maintenance of a constant base Gummel number together with a slight decrease in emitter doping level is optimum for future double-polysilicon structures. Transistors fabricated using the relaxed scale design concept have adequate gain for most digital applications and ECL circuits switch at sub-100 pS speeds at 87 K. Further advances with technology evolution are anticipated.

Cressler, John D.

1990-01-01

83

Transferred substrate heterojunction bipolar transistors for submillimeter wave applications  

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

84

InGaP/GaAs/InGaP double-heterojunction bipolar transistors grown by solid-source molecular-beam epitaxy with a valved phosphorus cracker  

E-print Network

InGaP/GaAs/InGaP double-heterojunction bipolar transistors grown by solid-source molecular-heterojunction bipolar transistor is reported, the device is grown in a solid source molecular beam epitaxy system-heterojunction bipolar transis- tor SHBT 5­7 as well as optical devices8 by a valved phos- phorus cracker have been

Woodall, Jerry M.

85

Device operation of InGaN heterojunction bipolar transistors with a graded emitter-base design  

E-print Network

and a thin emitter 50 nm grown on SiC substrates. This work demonstrates that InGaN HBTs with a graded InGaNDevice operation of InGaN heterojunction bipolar transistors with a graded emitter-base design T online 1 May 2006 The device operation of InGaN heterojunction bipolar transistors with a graded InGaN

Asbeck, Peter M.

86

e bipolar junction transistor (BJT) is historically the first solid-state analog amplifier and digital switch, and formed the basis of integrated circuits (IC) in the 1970s. Starting in the early 1980s, the  

E-print Network

9-1 e bipolar junction transistor (BJT) is historically the first solid-state analog amplifier, the invention of silicon­germanium base heterojunction bipolar transistor (SiGe HBT) brought the bipolar are injected from the emitter to base, 9 Bipolar Junction Transistor 9.1 Ebers­Moll Model

Wilamowski, Bogdan Maciej

87

Monolithic barrier-all-around high electron mobility transistor with planar GaAs nanowire channel.  

PubMed

High-quality growth of planar GaAs nanowires (NWs) with widths as small as 35 nm is realized by comprehensively mapping the parameter space of group III flow, V/III ratio, and temperature as the size of the NWs scales down. Using a growth mode modulation scheme for the NW and thin film barrier layers, monolithically integrated AlGaAs barrier-all-around planar GaAs NW high electron mobility transistors (NW-HEMTs) are achieved. The peak extrinsic transconductance, drive current, and effective electron velocity are 550 ?S/?m, 435 ?A/?m, and ~2.9 × 10(7) cm/s, respectively, at 2 V supply voltage with a gate length of 120 nm. The excellent DC performance demonstrated here shows the potential of this bottom-up planar NW technology for low-power high-speed very-large-scale-integration (VLSI) circuits. PMID:23635023

Miao, Xin; Zhang, Chen; Li, Xiuling

2013-06-12

88

SiC bipolar transistors for RF applications  

Microsoft Academic Search

The wide bandgap (WBG) semiconductor SiC has been identified as a potential candidate for use in high power and high frequency devices due to its superior material parameters. SiC has a breakdown field almost six times higher than that of Si or GaAs resulting in a higher attainable power density. SiC has a larger thermal conductivity, 3 times that of

I. Perez-Wurfl; R. Krutsinger; J. T. Torvik; B. Van Zeghbroeck

2001-01-01

89

Bipolar transistor modeling of avalanche generation for computer circuit simulation  

Microsoft Academic Search

An avalanche generation model is developed and incorporated into computer circuit analysis programs SLIC and NICAP. A modified form of Miller's empirical expression for generation is found to agree well with measured data for Western Electric and commercial n-p-n transistors. Measurement techniques and parameter determination for the three model coefficients are discussed. Equation constraints appropriate for computer implementation are presented.

R. W. Dutton

1975-01-01

90

Complementary GaAs junction-gated heterostructure field effect transistor fabrication for integrated circuits  

Microsoft Academic Search

A new GaAs junction-gated complementary logic technology that integrates a modulation doped p-channel heterostructure field effect transistor (pHFET) and a fully ion implanted n-channel JFET has recently been fabricated. High-speed, low-power operation has been demonstrated with loaded ring oscillators that show gate delays of 179 ps\\/stage for a power-delay product of 28 fJ at 1.2 V operation and 320 ps\\/stage

A. G. Baca; J. C. Zolper; M. E. Sherwin; P. J. Robertson; R. J. Shul; A. J. Howard; D. J. Rieger; J. F. Klem

1994-01-01

91

Application of insulated gate bipolar transistor to zero-current switching converters  

Microsoft Academic Search

The problems associated with insulated-gate bipolar transistor (IGBT) devices in PWM converters, such as turn-off current tailing and turn-off latching, are largely avoided in zero-current switching resonant converters. Phenomena induced by dv\\/dt, such as the power losses and latching, are identified as the predominant problems in using IGBT devices for very-high-frequency resonant operations. The discussion and the verification of the

R. Rangan; DAN Y. CHEN; Jian Yang; JOHN LEE

1989-01-01

92

IEEE BCTM 1.1 Current Status of GaN HeterojunctionBipolar Transistors  

E-print Network

and breakdown voltage relationships of silicon BJT,SiGe HBT,GaAs HBT,InP HBT, InP PHEMT, GaN HFET, and predictedIEEE BCTM 1.1 Current Status of GaN HeterojunctionBipolar Transistors M. Feng', R. K. Price', R the current stateaf-the art GaN HBT results, aud discusses advantagesof CaN HBTs over GaN HFETs and other

Asbeck, Peter M.

93

An improved understanding for the transient operation of the power insulated gate bipolar transistor (IGBT)  

Microsoft Academic Search

It is shown that a nonquasi-static analysis must be used to describe the transient current and voltage waveforms of the insulated gate bipolar transistor. The nonquasi-static analysis is necessary because the transport of electrons and holes are coupled for the low-gain, high-level injection conditions, and the quasi-neutral base width changes faster than the base transit speed for typical load circuit

1990-01-01

94

An investigation of the drive circuit requirements for the power insulated gate bipolar transistor (IGBT)  

Microsoft Academic Search

The drive circuit requirements of the insulated gate bipolar transistor (IGBT) are explained with the aid of an analytical model. It is shown that nonquasi-static effects limit the influence of the drive circuit on the time rate-of-change of anode voltage. Model results are compared with measured turn-on and turn-off waveforms for different drive, load, and feedback circuits, and for different

1991-01-01

95

75GHz fT SiGe-base heterojunction bipolar transistors  

Microsoft Academic Search

The fabrication of silicon heterojunction bipolar transistors which have a record unity-current-gain cutoff frequency (fT) of 75 GHz for a collector-base bias of 1 V, an intrinsic base sheet resistance (Rbi) of 17 k?\\/□, and an emitter width of 0.9 ?m is discussed. This performance level, which represents an increase by almost a factor of 2 in the speed of

GARY L. PATTON; JAMES H. COMFORT; BERNARD S. MEYERSON; E. F. Crabbe; G. J. Scilla; E. de Fresart; J. M. C. Stork; J. Y.-C. Sun; D. L. Harame; J. N. Burghartz

1990-01-01

96

Radiation Effects on Bipolar and MOS Transistors Made in Bicmos Technology  

NASA Astrophysics Data System (ADS)

Bipolar transistors were irradiated by neutrons, ions, or by both of them. Fast neutrons, as well as other types of particles, produce defects, mainly by displacing silicon atoms from their lattice positions to interstitial locations, i.e. generating vacancy-interstitial pairs, the so-called Frenkel pairs. The experimental results indicate that the gain variation is linearly related to the non-ionizing energy loss (NIEL) deposition for both neutrons and incoming ions.

Codegoni, D.; Croitoru, N.; D'Angelo, P.; Fallica, G.; Favalli, A.; Leonardi, S.; Modica, R.; Rancoita, P. G.; Seidman, A.

2004-07-01

97

Vertical profile optimization of very high frequency epitaxial Si and SiGe-base bipolar transistors  

Microsoft Academic Search

Bipolar transistors with phosphorus-doped emitters and sub-50 nm epitaxial bases have been fabricated in a low thermal-cycle process to explore the trade-offs between cutoff frequency, breakdown voltage and Early voltage. Record peak fTs of 73 GHz for a Si BJT and 113 GHz for a SiGe HBT with respective ?VA products of 630 and 48,400 V were obtained for intrinsic

E. F. Crabbe; B. S. Meyerson; J. M. C. Stork; D. L. Harame

1993-01-01

98

Characteristics of Spike-Free Single and Double Heterostructure-Emitter Bipolar Transistors  

Microsoft Academic Search

In this study, we propose single and double heterostructure-emitter bipolar transistors (SHEBTs and DHEBT, respectively) with undoped spacers inserted on both sides of the base. The spike-free HEBT is achieved by solving Poisson's equation. The SHEBT and DHEBT with 100 Å spacers exhibit common-emitter current gains of 200 and 120, along with offset voltages of 80 and 50 mV, respectively.

Yu-Shyan Lin; Wei-Chou Hsu; Fuh-Cheng Jong; Yu-Zung Chiou; Yeong-Jia Chen; Jing-Jou Tang

2004-01-01

99

Breakdown characteristics of InP\\/InGaAs composite-collector double heterojunction bipolar transistor  

Microsoft Academic Search

This investigation proposes an InP\\/InGaAs composite-collector double heterojunction bipolar transistor (CC-DHBT) grown by metalorganic chemical vapor deposition. The improved structure exhibits the advantages of no knee-shaped characteristics, no switching effect, low output conductance, a high two-terminal base-collector breakdown voltage (BV) that exceeds 20 V, and high three-terminal breakdown voltages (BVCEO>15 V, BVCBO>20 V). The current gain is over unity at

Y. S. Lin

2003-01-01

100

Breakdown characteristics of InP\\/InGaAs composite-collector double heterojunction bipolar transistor  

Microsoft Academic Search

This investigation proposes an InP\\/InGaAs composite-collector double heterojunction bipolar transistor (CC-DHBT) grown by metalorganic chemical vapor deposition. The improved structure exhibits the advantages of no knee-shaped characteristics, no switching effect, low output conductance, a high two-terminal base–collector breakdown voltage (BV) that exceeds 20 V, and high three-terminal breakdown voltages (BVCEO>15 V,BVCBO>20 V). The current gain is over unity at ultralow

Y. S. Lin

2003-01-01

101

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

NASA Astrophysics Data System (ADS)

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.

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

1988-12-01

102

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

NASA Technical Reports Server (NTRS)

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.

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

2006-01-01

103

Tunneling-triggered bipolar action in junctionless tunnel field-effect transistor  

NASA Astrophysics Data System (ADS)

We analyse a novel hybrid semiconductor field-effect transistor (FET), known as the junctionless tunnel FET (JL-TFET). We show that a parasitic bipolar transistor action, which is highly undesirable in conventional metal/oxide/semiconductor FETs and junctionless transistors, is the mechanism that activates the JL-TFET ON state. It is found that the sub-threshold slope (SS) in the JL-TFET is strongly dependent on the silicon thickness and a sub-60 mV/decade SS is observed for a thin silicon body only. We further study the JL-TFET design parameters as regards the effects of the control gate workfunction, P-gate workfunction, and isolation region on the JL-TFET characteristics.

Gundapaneni, Suresh; Goswami, Aranya; Badami, Oves; Cuduvally, Ramya; Konar, Aniruddha; Bajaj, Mohit; Murali, Kota V. R. M.

2014-12-01

104

On the AlGaInP-bulk and AlGaInP/GaAs-superlattice confinement effects for heterostructure-emitter bipolar transistors  

NASA Astrophysics Data System (ADS)

The confinement effect and electrical characteristics of heterostructure-emitter bipolar transistors with an AlGaInP bulk-confinement layer and an AlGaInP/GaAs superlattice-confinement layer are first demonstrated and compared by experimentally results. In the two devices, the relatively large valence band discontinuity at AlGaInP/GaAs heterojunction provides excellent confinement effect for holes to enhance current gain. As to the AlGaInP/GaAs superlattice-confinement device, part of thermionic-emission electrons will be trapped in the GaAs quantum wells of the superlattice. This will result in lower collector current and current gain as compared with the bulk-confinement device. Nevertheless, the superlattice-confinement device exhibits a larger current-gain cutoff frequency, which can be attributed that the tunneling behavior is included in the carrier transportation and transporting time across the emitter region could be substantially reduced.

Tsai, Jung-Hui

2015-02-01

105

A scalable high-frequency noise model for bipolar transistors with application to optimal transistor sizing for low-noise amplifier design  

Microsoft Academic Search

Fully scalable, analytical HF noise parameter equations for bipolar transistors are presented and experimentally tested on high-speed Si and SiGe technologies. A technique for extracting the complete set of transistor noise parameters from Y parameter measurements only is developed and verified. Finally, the noise equations are coupled with scalable variants of the HICUM and SPICE-Gummel-Poon models and are employed in

Sorin P. Voinigescu; Michael C. Maliepaard; Jonathan L. Showell; Greg E. Babcock; David Marchesan; Michael Schroter; Peter Schvan; David L. Harame

1997-01-01

106

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

SciTech Connect

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.

Campbell, Phillip Montgomery; Wix, Steven D.

2013-05-01

107

Investigation of InGaP\\/GaAs double-delta-doped heterojunction bipolar transistor  

Microsoft Academic Search

The double-delta-doped heterojunction bipolar transistor 0268-1242\\/13\\/6\\/015\\/img1 is successfully fabricated with improved current-voltage characteristics by employing the insertion of delta-doped sheets at emitter-base (E-B) and base-collector (B-C) heterojunction. Because of the use of delta-doped sheets, the potential spikes at E-B and B-C heterojunction are suppressed substantially. Thus a higher emitter injection efficiency (current gain) and a lower knee voltage are obtained.

W.-C. Wang; S.-Y. Cheng; W.-L. Chang; H.-J. Pan; Y.-H. Shie; W.-C. Liu

1998-01-01

108

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

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

109

Temperature dependence of current gain in 4H-SiC bipolar junction transistors  

NASA Astrophysics Data System (ADS)

The temperature dependence of current gain from 140 to 460 K in 4H-SiC bipolar junction transistors (SiC BJTs) was investigated. The current gain increased from 110 to 1200 with decreasing temperature from 460 to 200 K. The high current gain at the low temperature can be ascribed to the enhanced incomplete ionization of aluminum acceptors in the base layer, resulting in the increase in injection efficiency. However, when the temperature was further reduced from 200 to 140 K, the current gain decreased from 1200 to 515, which is caused by high injection condition in the base layer, because of a very low hole concentration below 200 K.

Asada, Satoshi; Okuda, Takafumi; Kimoto, Tsunenobu; Suda, Jun

2015-04-01

110

Large-scale transient sensitivity analysis of a radiation damaged bipolar junction transistor.  

SciTech Connect

Automatic differentiation (AD) is useful in transient sensitivity analysis of a computational simulation of a bipolar junction transistor subject to radiation damage. We used forward-mode AD, implemented in a new Trilinos package called Sacado, to compute analytic derivatives for implicit time integration and forward sensitivity analysis. Sacado addresses element-based simulation codes written in C++ and works well with forward sensitivity analysis as implemented in the Trilinos time-integration package Rythmos. The forward sensitivity calculation is significantly more efficient and robust than finite differencing.

Hoekstra, Robert John; Gay, David M.; Bartlett, Roscoe Ainsworth; Phipps, Eric Todd

2007-11-01

111

A high-voltage optoelectronic GaAs static induction transistor  

SciTech Connect

Experimental realization of an optically activated, high-voltage GaAs static induction transistor (SIT) is reported. In the forward blocking state, the breakdown voltage of the device was [approximately]200 V, while in the conduction state, on-state current densities exceeding 150 A/cm[sup 2] were obtained. In the floating-gate configuration (gate open), the specific on-resistance of the device was [approximately]50 m[Omega] [center dot] cm[sup 2]. Optical modulation of the device was achieved using a compact semiconductor laser array as the triggering source, In this mode, a gate-coupled RC network was implemented, resulting in an average switching energy gain (load energy/optical energy) of [approximately]30. This mode of operation is applicable to series-coupled devices for pulsed switching at higher power levels.

Hadizad, P.; Hur, J.H.; Zhao, H.; Kaviani, K.; Gundersen, M.A. (Univ. of Southern California, Los Angeles (United States)); Fetterman, H.R. (Univ. of California, Los Angeles (United States))

1993-04-01

112

Radiation-induced surface degradation of GaAs and high electron mobility transistor structures  

SciTech Connect

Transistor heterostructures with high-carrier-mobility have been studied. It is shown that, as the {gamma}-irradiation dose {Phi} increases, their degradation occurs in the following sequence. (i) At {Phi} < 10{sup 7} rad, the GaAs surface layer is damaged to a depth of 10 nm due to a >0.2-eV decrease in the diffusion energy of intrinsic defects and, probably, atmospheric oxygen. (ii) At {Phi} > 10{sup 7} rad, highly structurally disordered regions larger than 1 {mu}m are formed near microscopic defects or dislocations. (iii) At {Phi} > 10{sup 8} rad, there occurs degradation of the internal AlGaAs/InGaAs/GaAs interfaces and the working channel. An effective method for studying the degradation processes in heterostructures is to employ a set of structural diagnostic methods to analyze processes of radiation-induced and aging degradation, in combination with theoretical simulation of the occurring processes.

Bobyl, A. V.; Konnikov, S. G.; Ustinov, V. M.; Baidakova, M. V.; Maleev, N. A.; Sakseev, D. A. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Konakova, R. V., E-mail: konakova@isp.kiev.ua; Milenin, V. V.; Prokopenko, I. V. [National Academy of Sciences of Ukraine, Lashkaryov Institute of Semiconductor Physics (Ukraine)

2012-06-15

113

Passivation Effects of 100 nm In0:4AlAs/In0:35GaAs Metamorphic High-Electron-Mobility Transistors with a Silicon Nitride Layer  

E-print Network

Passivation Effects of 100 nm In0:4AlAs/In0:35GaAs Metamorphic High-Electron-Mobility TransistorsAs metamorphic high-electron-mobility transistors (MHEMTs) have been successfully fabricated. In order to reduce.2341] KEYWORDS: GaAs, metamorphic, high-electron-mobility transistor, remote PECVD, recess, passivation

Seo, Kwang Seok

114

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

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

115

Thermodynamic Field Theory of the Dynamic Behavior of Bipolar Junction Transistors.  

NASA Astrophysics Data System (ADS)

Bipolar junction transistors play an important role in integrated-circuits, whether monolithic, or hybrid. Integrated circuit designers are obliged to use as many transistors as they can in their design, since this entails very little increase in cost. More importantly, a bipolar transistor in an integrated circuit can be connected to substitute for other components that are hard to be integrated in the same substrate. The thermodynamic field theory of generalized fields (TTGF) has had success for predicting the voltage current relationship in p-n junctions and solar cells in d-c cases. The primary object of this thesis is to apply the thermodynamic field theory to an interfacial problem which has time-varying fields. Specifically, we shall apply the concepts of TTGF to investigate the dynamic response of p-n junction devices when fed a small a-c signal. In previous applications of the TTGF, single junction devices have been considered. In this study, we apply the TTGF to a multijunction device: the bipolar transistor. In Chapter I, a brief introduction and literature review are given. In Chapter II, an introduction to the TTGF is given. Included also is a recently derived TTGF equation which governs the interaction of time varying fields in a system involving interfaces and carriers which may recombine and accumulate. Chapter III is a review for the one dimensional solution of the continuity equation. Both the d-c and a-c solutions are reviewed. In Chapter IV, the reverse biased junction is covered from the point of view of the TTGF. Force fields are identified, evaluated and the work done on the composite carrier in the respective regions is calculated. Chapter V covers the forward biased junction. Work done by force fields has been calculated. Energy due to carrier accumulation and recombination has been calculated. The law of conservation energy has been applied over the emitter-base and the emitter-base-collector loops. From the resulting equations, the input admittance of the common emitter transistor configuration has been calculated. Comparison between theory and experiment is provided. Finally, in Chapter VI, a conclusion has been drawn. Suggested future studies also have been given.

Aboulwafa, Mohamed El-Sayed

116

A new InGaP\\/GaAs double delta-doped heterojunction bipolar transistor (D 3HBT)  

Microsoft Academic Search

A new InGaP\\/GaAs double delta-doped heterojunction bipolar transistor (D3HBT) has been fabricated successfully and demonstrated. Due to the employment of delta-doped sheets, the potential spikes at emitter–base (E–B) and base–collector (B–C) heterojunctions are suppressed considerably. Therefore, good transistor performance including higher current gain and lower knee voltage are obtained.

Shiou-Ying Cheng; Wei-Chou Wang; Wen-Lung Chang; Jing-Yuh Chen; His-Jen Pan; Wen-Chau Liu

1999-01-01

117

Direct extraction of the AlGaAs\\/GaAs heterojunction bipolar transistor small-signal equivalent circuit  

Microsoft Academic Search

The authors describe a novel, direct technique for determining the small-signal equivalent circuit of a heterojunction bipolar transistor (HBT). The parasitic elements are largely determined from measurements of test structures, reducing the number of elements determined from measurements of the transistor. The intrinsic circuit elements are evaluated from y-parameter data, which are DC-embedded from the known parasitics. The equivalent-circuit elements

Damian Costa; William U. Liu; James S. Harris

1991-01-01

118

73GHz self-aligned SiGe-base bipolar transistors with phosphorus-doped polysilicon emitters  

Microsoft Academic Search

The authors report a thermal-cycle emitter process using phosphorus for the fabrication of self-aligned SiGe-base heterojunction bipolar transistors. The low thermal cycle results in extremely, narrow basewidths and preservation of lightly doped spacers in both the emitter-base and base-collector junctions for improved breakdown. Transistors with 35-nm basewidths were obtained with low emitter-base reverse leakage and a peak cutoff frequency of

E. F. Crabbe; James H. Comfort; Wai Lee; John D. Cressler; Bernard S. Meyerson; Andrew C. Megdanis; Jack Y.-C. Sun; Johannes M. C. Stork

1992-01-01

119

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

Microsoft Academic Search

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

D. A. Boardman; P. J. Sellin

2001-01-01

120

Fabrication of InP-based Optoelectronic Integrated Circuit (OEIC) Photoreceivers Using Shared Layer Integration of Heterojunction Bipolar Transistors  

E-print Network

Fabrication of InP-based Optoelectronic Integrated Circuit (OEIC) Photoreceivers Using Shared LayerP-based monolithic photoreceivers have been fabricated using a shared layer integration scheme of refracting-facet photodiodes (RFPDs) and heterojunction bipolar transistors (HBTs). An HBT was fabricated using a self

Yang, Kyounghoon

121

Negative differential transconductance in silicon quantum well metal-oxide-semiconductor field effect/bipolar hybrid transistors  

NASA Astrophysics Data System (ADS)

Introducing explicit quantum transport into Si transistors in a manner amenable to industrial fabrication has proven challenging. Hybrid field-effect/bipolar Si transistors fabricated on an industrial 45 nm process line are shown to demonstrate explicit quantum transport signatures. These transistors incorporate a lateral ion implantation-defined quantum well (QW) whose potential depth is controlled by a gate voltage (VG). Quantum transport in the form of negative differential transconductance (NDTC) is observed to temperatures >200 K. The NDTC is tied to a non-monotonic dependence of bipolar current gain on VG that reduces drain-source current through the QW. These devices establish the feasibility of exploiting quantum transport to transform the performance horizons of Si devices fabricated in an industrially scalable manner.

Naquin, Clint; Lee, Mark; Edwards, Hal; Mathur, Guru; Chatterjee, Tathagata; Maggio, Ken

2014-11-01

122

New AlGaAs/GaAs double heterostructure-emitter bipolar transistor prepared by molecular beam epitaxy  

NASA Astrophysics Data System (ADS)

A new AlGaAs/GaAs double heterostructure-emitter bipolar transistor (DHEBT) prepared by molecular beam epitaxy (MBE) has been demonstrated. Due to the symmetric structure with respect to the base layer, the device would operate as a bi-directional transistor and switch. The common-emitter current gain for up to 18, with an offset voltage smaller than 0.1 V, is obtained. Furthermore, the undesired knee-shaped characteristics and the reachthrough effect observed in the conventional double heterojunction bipolar transistor (DHBT) are avoided. The bi-directional operations of this structure give a significant flexibility in the circuit applications. It is believed that with adequate adjustments on structural parameters, especially in the minimization of the base-collector junction area, a more symmetric and an improved electrical performance may be achieved.

Liu, Wen-Chau; Lour, Wen-Shiung; Guo, Der-Feng

1992-01-01

123

Growth and Fabrication of GaN/AlGaN Heterojunction Bipolar Transistor  

SciTech Connect

A GaN/AlGaN heterojunction bipolar transistor structure with Mg doping in the base and Si Doping in the emitter and collector regions was grown by Metal Organic Chemical Vapor Deposition in c-axis Al(2)O(3). Secondary Ion Mass Spectrometry measurements showed no increase in the O concentration (2-3x10(18) cm(-3)) in the AlGaN emitter and fairly low levels of C (~4-5x10(17) cm (-3)) throughout the structure. Due to the non-ohmic behavior of the base contact at room temperature, the current gain of large area (~90 um diameter) devices was <3. Increasing the device operating temperature led to higher ionization fractions of the mg acceptors in the base, and current gains of ~10 were obtained at 300 degree C.

Abernathy, C.R.; Baca, A.G.; Cao, X.A.; Cho, H.; Dang, G.T.; Donovan, S.M.; Han, J.; Jung, K.B.; Pearton, S.J.; Ren, F.; Shul, R.J.; Willison, C.G.; Wilson, R.G.; Zhang, A.P.; Zhang, L

1999-03-16

124

Analysis of long-term ionizing radiation effects in bipolar transistors  

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

125

Implementation of total dose effects in the bipolar junction transistor Gummel-Poon model  

SciTech Connect

The effects of total dose on the SPICE model of bipolar junction transistors are investigated. The limitations of the standard Gummel-Poon model for simulating the radiation-induced excess base current are analyzed, and a new model based on an empirical approach is proposed. Four new SPICE rad-parameters are presented, and investigated for different dose rates. The relevant parameters are extracted using a new algorithmic procedure, combining a genetic approach and the standard optimization technique which minimizes the RMS error between measured and simulated excess base current. It is shown that the excess base current is accurately described by the same formula whatever the device type is. An empirical fitting of the rad-parameters as a function of total dose is proposed to use in hardening electronic circuits for space-like environments.

Montagner, X.; Fouillat, P.; Briand, R.; Touboul, A. [Univ. of Bordeaux I, Talence (France)] [Univ. of Bordeaux I, Talence (France); Schrimpf, R.D.; Galloway, K.F. [Vanderbilt Univ., Nashville, TN (United States)] [Vanderbilt Univ., Nashville, TN (United States); Calvet, M.C. [Aerospatiale, Les Mureaux (France)] [Aerospatiale, Les Mureaux (France); Calvel, P. [Alcatel Telecom, Toulouse (France)] [Alcatel Telecom, Toulouse (France)

1997-12-01

126

Microwave damage susceptibility trend of a bipolar transistor as a function of frequency  

NASA Astrophysics Data System (ADS)

We conduct a theoretical study of the damage susceptibility trend of a typical bipolar transistor induced by a high-power microwave (HPM) as a function of frequency. The dependences of the burnout time and the damage power on the signal frequency are obtained. Studies of the internal damage process and the mechanism of the device are carried out from the variation analysis of the distribution of the electric field, current density, and temperature. The investigation shows that the burnout time linearly depends on the signal frequency. The current density and the electric field at the damage position decrease with increasing frequency. Meanwhile, the temperature elevation occurs in the area between the p-n junction and the n-n+ interface due to the increase of the electric field. Adopting the data analysis software, the relationship between the damage power and frequency is obtained. Moreover, the thickness of the substrate has a significant effect on the burnout time.

Ma, Zhen-Yang; Chai, Chang-Chun; Ren, Xing-Rong; Yang, Yin-Tang; Chen, Bin; Song, Kun; Zhao, Ying-Bo

2012-09-01

127

Cryogenically cooled broad-band GaAs field-effect transistor preamplifier  

SciTech Connect

The Antiproton Source of the Fermi National Accelerator Laboratory will be capable of accumulating a total of 4.3 x 10/sup 11/ antiprotons in four hours when a wide-band feedback system for stochastic beam cooling is used. The feedback system detects and corrects at every revolution, the statistical fluctuations of the beam position and momentum. One of the essential components of such a system is a low-noise broad-band preamplifier. Acryogenically cooled 1 to 2 GHz low-noise broad-band prototype preamplifier utilizing GaAs field-effect transistors is described for this application. The preamplifier has an average gain of 30 dB and 35 dB at ambient temperatures of 293/sup 0/K and 18/sup 0/K, respectively. The noise figure has a minimum value of 0.75 dB at 300/sup 0/K and 0.24 dB at 18/sup 0/K. The optimum preamplifier operating conditions for a minimum noise figure at temperatures of 293/sup 0/K, 80/sup 0/K and 18/sup 0/K are given and are discussed. Also, the phase-shift characteristics, the input and output voltage standing-wave ratio as a function of frequency and intermodulation products content as a function of the input power level were measured.

Lo, C.C.; Leskovar, B.

1983-10-01

128

Silicon germanium heterojunction bipolar technology: the next leap in silicon?  

Microsoft Academic Search

SiGe heterostructure bipolar transistor (HBT) technology will allow circuit designers to combine the performance historically associated with compound semiconductor technologies such as GaAs with the integration levels, yield, and cost associated with conventional Si processing. At present, unloaded SiGe ECL circuits switch at sub20ps speeds, transistors exhibit cutoff frequencies in excess of 100GHz, and integration levels high enough to realize

John D. Cressler; D. L. Harame; J. H. Comfort; Johannes M. C. Stork; Bernard S. Meyerson; Thomas E. Tice

1994-01-01

129

Simulation of neutron displacement damage in bipolar junction transistors using high-energy heavy ion beams.  

SciTech Connect

Electronic components such as bipolar junction transistors (BJTs) are damaged when they are exposed to radiation and, as a result, their performance can significantly degrade. In certain environments the radiation consists of short, high flux pulses of neutrons. Electronics components have traditionally been tested against short neutron pulses in pulsed nuclear reactors. These reactors are becoming less and less available; many of them were shut down permanently in the past few years. Therefore, new methods using radiation sources other than pulsed nuclear reactors needed to be developed. Neutrons affect semiconductors such as Si by causing atomic displacements of Si atoms. The recoiled Si atom creates a collision cascade which leads to displacements in Si. Since heavy ions create similar cascades in Si we can use them to create similar damage to what neutrons create. This LDRD successfully developed a new technique using easily available particle accelerators to provide an alternative to pulsed nuclear reactors to study the displacement damage and subsequent transient annealing that occurs in various transistor devices and potentially qualify them against radiation effects caused by pulsed neutrons.

Doyle, Barney Lee; Buller, Daniel L.; Hjalmarson, Harold Paul; Fleming, Robert M; Bielejec, Edward Salvador; Vizkelethy, Gyorgy

2006-12-01

130

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

SciTech Connect

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 {Kappa}, 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/sup 19/ cm/sup -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 {Kappa}. 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/sup 19/ cm/sup -3/ while keeping the base thickness constant, the minimum delay at liquid nitrogen can approach the delay of optimized devices at room temperature.

Stork, J.M.C.; Harame, D.L.; Meyerson, B.S.; Nguyen, T.N. (International Business Machines Corp., Yorktown Heights, NY (USA). Thomas J. Watson Research Center)

1989-08-01

131

Power gain performance enhancement of independently biased heterojunction bipolar transistor cascode chip  

NASA Astrophysics Data System (ADS)

The purpose of this research is to study the power gain performance of an independently biased cascode structure or a new cascode structure (NCS) in comparison to that of a conventional cascode structure (CCS) at 1.9 GHz while investigating the bias conditions. We found that the bias collector current (Ic2) of the common-base (CB) or second-stage transistor is the key factor contributing to the power gain difference between a NCS and a CCS. By employing a monolithic microwave integrated circuit (MMIC) InGaP/GaAs heterojunction bipolar transistor (HBT), simulation and experimental results show that a NCS with higher Ic2 than that of a CCS can offer better power gain performance but less stability compared with a CCS. On the other hand, although a NCS with lower Ic2 than that of a CCS exhibits worse power gain performance compared with a CCS, it can be more stable than a CCS. All of the above indicate that a NCS can deliver superior radio frequency (RF) performance compared with a CCS by setting the appropriate bias conditions.

Luong, Duy Manh; Takayama, Yoichiro; Ishikawa, Ryo; Honjo, Kazuhiko

2015-04-01

132

The influence of a doping profile on the characteristics of an ion-implanted GaAs field-effect transistor with a Schottky barrier  

SciTech Connect

A GaAs field-effect ion-implanted transistor with a Schottky barrier is simulated. The doping profile obtained when doping through an insulator mask is determined and the dependences of the static transistor characteristics on the parameters of the doping profile are calculated and analyzed. The physical processes controlling the transistor characteristics in the case of a variation in the parameters of its doping profile and the coefficient of compensation of the substrate are studied. Based on calculations, the optimal doping-profile parameters ensuring the best characteristics for transistors are predicted.

Shestakov, A. K., E-mail: shestakov@thermo.isp.nsc.ru; Zhuravlev, K. S. [Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics, Siberian Branch (Russian Federation)

2011-12-15

133

Note: cryogenic low-noise dc-coupled wideband differential amplifier based on SiGe heterojunction bipolar transistors.  

PubMed

Silicon-germanium heterojunction bipolar transistors can be used to construct low-noise cryogenic amplifiers. We present a dc-coupled differential amplifier capable of operating down to 10 K. In this temperature regime it has bandwidth of 15 MHz and noise temperature as low as 1.3 K. When operated at liquid nitrogen temperature of 77 K, the measured noise temperature is lower than 3 K. The amplifier is based on the commercially available transistors NESG3031 and operational amplifier OPA836 and is capable of standalone operation without any additional stages at room temperature. PMID:22755673

Beev, Nikolai; Kiviranta, Mikko

2012-06-01

134

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

NASA Technical Reports Server (NTRS)

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.

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

2003-01-01

135

IEEE ELECTRON DEVICE LETTERS, VOL. 20, NO. 6, JUNE 1999 277 AlGaN/GaN Heterojunction Bipolar Transistor  

E-print Network

, higher linearity and higher current densities than FET's. Transistors with GaN emitters grown on SiC base doped (UID) n-type GaN collector, a p-type (Mg doped) GaN base, and an n-type (Si doped) Al Ga N emitterIEEE ELECTRON DEVICE LETTERS, VOL. 20, NO. 6, JUNE 1999 277 AlGaN/GaN Heterojunction Bipolar

Rodwell, Mark J. W.

136

Evaluation of the Radiation Tolerance of SiGe Heterojunction Bipolar Transistors Under 24GeV Proton Exposure  

Microsoft Academic Search

For the potential use in future high luminosity applications in high energy physics (HEP) [e.g., the Large Hadron Collider (LHC) upgrade], we evaluated the radiation tolerance of a candidate technology for the front-end of the readout application-specific integrated circuit (ASIC) for silicon strip detectors. The devices investigated were first-generation silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs). The current gain as a

J. Metcalfe; D. E. Dorfan; A. A. Grillo; A. Jones; D. Lucia; F. Martinez-McKinney; M. Mendoza; M. Rogers; H. F.-W. Sadrozinski; A. Seiden; E. Spencer; M. Wilder; J. D. Cressler; G. Prakash; A. Sutton

2006-01-01

137

Microwave power performance of InP-based double heterojunction bipolar transistors for C- and X-band applications  

Microsoft Academic Search

We report on the microwave performance of InP-based double heterojunction bipolar transistors (DHBT) for X-band and C-band applications with power cells operating at an output power greater than 2 W. Our power performance characterization indicated a combination of high power density and high efficiency at both 4.5 and 9 GHz. At 4.5 GHz we measured over 2 W output power

M. Hafizi; P. A. Macdonald; T. Liu; D. B. Rensch; T. C. Cisco

1994-01-01

138

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

PubMed Central

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??m and nickel powder with grain size of 10 and 25??m 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. PMID:24959622

Smitka, Martin; Malcho, Milan

2014-01-01

139

A New Lateral Trench Electrode Insulated Gate Bipolar Transistor with p+ Diverter for Superior Electrical Characteristics  

NASA Astrophysics Data System (ADS)

A new lateral trench electrode insulated gate bipolar transistor (LTEIGBT) with a p+ diverter was proposed and fabricated to improve the electrical characteristics of the conventional LTIGBT. The p+ diverter was placed between anode and cathode electrodes. Because the p+ diverter region of the proposed device was an enclosed trench oxide layer, the electric field centered on the trench oxide layer and the punch-through breakdown of the LTEIGBT with a p+ diverter was occurred at a high. Therefore, the p+ diverter of the proposed LTIGBT was not related to the breakdown voltage in contrast to that of the conventional LTIGBT. As a result of device simulation, the electrical characteristics of the proposed LTEIGBT including latching current density, breakdown voltage and switching speed were superior to those of the conventional LIGBTs. After simulation, we fabricated and analyzed the proposed LTEIGBT with a p+ diverter. The maximum currents of the proposed and conventional LTIGBTs were 90 mA and 70 mA, respectively. Therefore, the proposed LTEIGBT with a p+ diverter is an effective device for a smart power IC.

Sung, Man Young; Kang, Ey Goo; Kim, Dae Jong; Kim, Sang sig

2003-04-01

140

Growth and fabrication of GaN/AlGaN heterojunction bipolar transistor  

SciTech Connect

A GaN/AlGaN heterojunction bipolar transistor structure with Mg doping in the base and Si doping in the emitter and collector regions was grown by metalorganic chemical vapor deposition on {ital c}-axis Al{sub 2}O{sub 3}. Secondary ion mass spectrometry measurements showed no increase in the O concentration (2{endash}3{times}10{sup 18} cm{sup {minus}3}) in the AlGaN emitter and fairly low levels of C ({approximately}4{endash}5{times}10{sup 17} cm{sup {minus}3}) throughout the structure. Due to the nonohmic behavior of the base contact at room temperature, the current gain of large area ({approximately}90 {mu}m diameter) devices was {lt}3. Increasing the device operating temperature led to higher ionization fractions of the Mg acceptors in the base, and current gains of {approximately}10 were obtained at 300 {degree}C. {copyright} {ital 1999 American Institute of Physics.}

Han, J.; Baca, A.G.; Shul, R.J.; Willison, C.G.; Zhang, L. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Ren, F.; Zhang, A.P.; Dang, G.T. [Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States)] [Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States); Donovan, S.M.; Cao, X.A.; Cho, H.; Jung, K.B.; Abernathy, C.R.; Pearton, S.J. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States)] [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Wilson, R.G. [Consultant, Stevenson Ranch, California 91381 (United States)] [Consultant, Stevenson Ranch, California 91381 (United States)

1999-05-01

141

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

NASA Technical Reports Server (NTRS)

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.

Niedra, Janis M.

2006-01-01

142

Silicon direct bonding approach to high voltage power device (insulated gate bipolar transistors)  

NASA Astrophysics Data System (ADS)

Silicon direct bonding technique was successfully applied for the fabrication of high voltage IGBT (Insulated Gate Bipolar Transistor). In this work, 5 inch, p-type CZ wafer for handle wafer and n-type FZ wafer for device wafer were used and bonding the two wafers was performed at reduced pressure (1mmTorr) using a modified vacuum bonding machine. Since the breakdown voltage in high voltage device has been determined by the remained thickness of device layer, grinding and CMP steps should be carefully designed in order to acquire better uniformity of device layer. In order to obtain the higher removal rate and the final better uniformity of device layer, the harmony of the two processes must be considered. We found that the concave type of grinding profile and the optimal thickness of ground wafer was able to reduce the process time of CMP step and also to enhance the final thickness uniformity of device layer up to +/- 1%. Finally, when compared epitaxy layer with SDB wafer, the SDB wafer was found to be more favorable in terms of cost and electrical characteristics.

Cha, Giho; Kim, Youngchul; Jang, Hyungwoo; Kang, Hyunsoon; Song, Changsub

2001-10-01

143

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

PubMed

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. PMID:24199954

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

2014-03-01

144

Investigation of VLSI Bipolar Transistors Irradiated with Electrons, Ions and Neutrons for Space Application  

NASA Astrophysics Data System (ADS)

A systematic investigation of radiation effects on a BICMOS technology manufactured by STM has been undertaken. Bipolar transistors were irradiated by neutrons, C, Ar and Kr ions, and recently by electrons. Fast neutrons, as well as other types of particles, produce defects mainly by displacing silicon atoms from their lattice positions to interstitial locations, i.e. generating vacancy-interstitial pairs (the so-called Frenkel pairs). Although imparted doses differ largely, the experimental results indicate that the gain (?) variation is mostly related to the non-ionizing energy-loss (NIEL) deposition for neutrons, ions and electrons. The variation of the inverse of the gain degradation, ?(1/?), is found to be linearly related (as predicted by the Messenger-Spratt equation for neutron irradiations) to the concentrations of the Frenkel pairs generated independently of the kind of incoming particle. For space applications, this linear dependence on the concentration of Frenkel pairs allows to evaluate the total amount of the gain degradation of VLSI components due to the flux of charged particles during the full life of operation of any pay-load. In fact, the total amount of expected Frenkel pairs can be estimated taking into account the isotopic spectra. It has to be point out that in cosmic rays there is relevant flux of electrons and isotopes up to Ni, which are within the range of particles presently investigated.

D'Angelo, P.; Fallica, G.; Galbiati, A.; Mangoni, R.; Modica, R.; Pensotti, S.; Rancoita, P. G.

2006-04-01

145

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

PubMed Central

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 100MHz. 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. PMID:24199954

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

2013-01-01

146

63-75 GHz fT SiGe-base heterojunction bipolar technology  

Microsoft Academic Search

Experimental results for maximum cut-off frequency (fT) values of 75 and 52 GHz were achieved for SiGe-base and Si-base bipolar transistors with intrinsic base sheet resistances in the 10-17 k?\\/square range. These results extend the speed of silicon bipolar devices into a regime previously reserved to GaAs and other compound semiconductor technologies. Excellent junction characteristics were also obtained for devices

G. L. Patton; J. H. Comfort; B. S. Meyerson; E. F. Crabbe; G. J. Scilla; E. de Fresart; J. M. C. Stork; J. Y.-C. Sun; D. L. Harame; J. Burghartz

1990-01-01

147

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

NASA Technical Reports Server (NTRS)

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.

Das, Kalyan; Hall, Harvey

1999-01-01

148

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

NASA Technical Reports Server (NTRS)

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.

Niedra, Janis M.

2006-01-01

149

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

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

150

Unified description of I-V characteristics in field-effect and bipolar transistors based on current density continuity equation solution  

NASA Astrophysics Data System (ADS)

A general approach to derive the current-voltage characteristics both for field-effect and bipolar transistors has been proposed based on exact solution of current continuity equation in diffusion-drift approximation taking into account nonuniformity of electric field and charge density distributions between the contacts. This approach describes in a unified manner both linear and saturation parts of MOSFET's I-V characteristics as for velocity saturation and for electrostatic pinch-off effect cases. It was shown also that the same design formula is appropriate for description of I-V characteristics in bipolar transistors.

Zebrev, G. I.

2014-12-01

151

GaAs field-effect transistor properties, as influenced by the local concentrations of midgap native donors and dislocations  

NASA Astrophysics Data System (ADS)

Results are presented of electrical parameter mapping for arrays of field-effect transistors (FET's) fabricated in semi-insulating GaAs wafers, compared with mapping data of the dislocation density and the neutral concentration of the main midgap donor defect (known as EL2) in the same wafers. The work seeks to clarify whether a ``shift'' of FET parameters such as threshold voltage Vth results directly from dislocation proximity, or whether such a shift results from FET sensitivity to the local EL2 concentration. For a wafer having quite different spatial distributions of EL2 and dislocations, the FET parameters were found to correlate strongly with the local neutral EL2 density, a high density promoting a larger channel current and a more negative Vth. Such results suggest that a reported sensitivity of Vth to dislocation proximity may arise from the role a dislocation can play as a source or sink for point defects.

Dobrilla, P.; Blakemore, J. S.; McCamant, A. J.; Gleason, K. R.; Koyama, R. Y.

1985-09-01

152

Graded-base InGaN/GaN heterojunction bipolar light-emitting transistors B. F. Chu-Kung,a  

E-print Network

Graded-base InGaN/GaN heterojunction bipolar light-emitting transistors B. F. Chu-Kung,a M. Feng, G; published online 25 August 2006 The authors report radiative recombination from a graded-base InGaN/GaN microwave power has been obtained from GaN field-effect transistors, very few operational GaN-based HBTs

Asbeck, Peter M.

153

Transistors  

NSDL National Science Digital Library

How does a transistor work ? History of semi-conductors Visit the museum of how the transistor was developed. Transistor history The Transistor Museum How stuff works Visit this site and follow through a short course on how a semi-conductor works. How stuff works PBS site Visit the PBS site of transistors and semi-conductors. Watch shorth videos on the development of the transistor. Timeline pbs ...

Mr. Blackburn

2004-07-05

154

Metamorphic In(0.3)Ga(0.7)As\\/In(0.29)Al(0.71)As layer on GaAs - A new structure for high performance high electron mobility transistor realization  

Microsoft Academic Search

A high-electron-mobility transistor (HEMT) using InAlAs\\/InGaAs grown on GaAs is realized. This structure, with an In content close to 30 percent, presents several advantages over conventional pseudomorphic HEMT on GaAs and lattice-matched HEMT on InP. To accommodate the mismatch between the active layer and the GaAs substrate, a metamorphic buffer is grown. High electron mobility with high 2D electron gas

P. Win; Y. Druelle; A. Cappy; Y. Cordier; J. Favre; C. Bouillet

1992-01-01

155

Explanation of Current Crowding Phenomena Induced by Impact Ionization in Advanced Si Bipolar Transistors by Means of Electrical Measurements and Light Emission Microscopy  

Microsoft Academic Search

This paper analyzes impact ionization phenomena in advanced polysilicon emitter bipolar transistors. Two intrinsic limitations affecting multiplication coefficient at high electric fields are discussed. Emission microscopy is adopted to directly investigate and observe current crowding effects at the basis of the first kind of instability, which takes place when the device is driven at constant emitter current IE. The second

Paolo Pavan; Loris Vendrame; Stefano Bigliardi; Arlette Marty; Alain Chantre; Enrico Zanoni

1992-01-01

156

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

NASA Astrophysics Data System (ADS)

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.

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

2015-02-01

157

Comparison of total dose effects on SiGe heterojunction bipolar transistors induced by different swift heavy ion irradiation  

NASA Astrophysics Data System (ADS)

The degradations in NPN silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) were fully studied in this work, by means of 25-MeV Si, 10-MeV Cl, 20-MeV Br, and 10-MeV Br ion irradiation, respectively. Electrical parameters such as the base current (IB), current gain (?), neutral base recombination (NBR), and Early voltage (VA) were investigated and used to evaluate the tolerance to heavy ion irradiation. Experimental results demonstrate that device degradations are indeed radiation-source-dependent, and the larger the ion nuclear energy loss is, the more the displacement damages are, and thereby the more serious the performance degradation is. The maximum degradation was observed in the transistors irradiated by 10-MeV Br. For 20-MeV and 10-MeV Br ion irradiation, an unexpected degradation in IC was observed and Early voltage decreased with increasing ion fluence, and NBR appeared to slow down at high ion fluence. The degradations in SiGe HBTs were mainly attributed to the displacement damages created by heavy ion irradiation in the transistors. The underlying physical mechanisms are analyzed and investigated in detail.

Sun, Ya-Bin; Fu, Jun; Xu, Jun; Wang, Yu-Dong; Zhou, Wei; Zhang, Wei; Cui, Jie; Li, Gao-Qing; Liu, Zhi-Hong

2014-11-01

158

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

PubMed

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. PMID:21730416

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

2007-10-01

159

Electrical stress-induced instability of amorphous indium-gallium-zinc oxide thin-film transistors under bipolar ac stress  

SciTech Connect

Bipolar ac stress-induced instability of amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors is comparatively investigated with that under a positive dc gate bias stress. While the positive dc gate bias stress-induced threshold voltage shift ({delta}V{sub T}) is caused by the charge trapping into the interface/gate dielectric as reported in previous works, the dominant mechanism of the ac stress-induced {delta}V{sub T} is observed to be due to the increase in the acceptorlike deep states of the density of states (DOS) in the a-IGZO active layer. Furthermore, it is found that the variation of deep states in the DOS makes a parallel shift in the I{sub DS}-V{sub GS} curve with an insignificant change in the subthreshold slope, as well as the deformation of the C{sub G}-V{sub G} curves.

Lee, Sangwon; Jeon, Kichan; Park, Jun-Hyun; Kim, Sungchul; Kong, Dongsik; Kim, Dong Myong; Kim, Dae Hwan [School of Electrical Engineering, Kookmin University, 861-1 Jeongneung-dong, Seongbuk-gu, Seoul 136-702 (Korea, Republic of); Kim, Sangwook; Kim, Sunil; Hur, Jihyun; Park, Jae Chul; Song, Ihun; Kim, Chang Jung; Park, Youngsoo; Jung, U-In [Semiconductor Laboratory, Samsung Advanced Institute of Technology, Nongseo-Dong, Giheung-Gu, Yongin-Si, Gyeonggi-Do 446-712 (Korea, Republic of)

2009-09-28

160

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

SciTech Connect

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.

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

161

A new InGaP/GaAs tunneling heterostructure-emitter bipolar transistor (T-HEBT)  

SciTech Connect

Excellent characteristics of an InGaP/GaAs tunneling heterostructure-emitter bipolar transistor (T-HEBT) are first demonstrated. The insertion of a thin n-GaAs emitter layer between tynneling confinement and base layers effectivelty eliminates the potential spike at base-emitter junction and reduces the collector-emitter offset voltage, while the thin InGaP tunneling confinement layer is employed to reduce the transporting time across emitter region for electrons and maintain the good confinement effect for holes. Experimentally, the studied T-HEBN exhibits a maximum current gain of 285, a relatively low offset voltage of 40 mW, and a current-gain cutoff frequency of 26.4 GHz.

Tsai, Jung-Hui, E-mail: jhtsai@nknucc.nknu.edu.tw [National Kaohsiung Normal University, Department of Electronic Engineering, Taiwan (China); Lee, Ching-Sung [Feng Chia University, Department of Electronic Engineering, Taiwan (China); Lour, Wen-Shiung [National Taiwan Ocean University, Department of Electrical Engineering, Taiwan (China); Ma, Yung-Chun; Ye, Sheng-Shiun [National Kaohsiung Normal University, Department of Electronic Engineering, Taiwan (China)

2011-05-15

162

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

NASA Astrophysics Data System (ADS)

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.

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

2010-07-01

163

Trench-Isolated High-Voltage IC with Reduced Parasitic Bipolar Transistor Action  

Microsoft Academic Search

For high-voltage IC device, one of the important issues is to prevent parasitic transistor acting, especially in junction-isolation (JI) device. In addition to this problem, it is necessary to achieve it by a minimum cost. In this paper, we propose junction-isolated HVIC using deep trench-isolation techniques. And we examined about structures of reducing parasitic transistor action by simulation and experiments.

Tetsuo Takahashi; Tomohide Terashima; J. Moritani

2007-01-01

164

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

PubMed

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 ?A/decade at base currents of -50, -30, and -10 ?A, 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. PMID:21835604

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

2011-10-15

165

Effects of output low impedance termination to linearity of GaAs HBT power amplifier  

Microsoft Academic Search

Improving linearity over a broad band is a major goal in RF design. This paper demonstrates that adding a low impedance termination at the envelope frequency (?2-?1) to the output of a Gallium Arsenide (GaAs) Heterojunction Bipolar Transistor (HBT) Distributed Amplifier (DA) improves the third order output intercept point (OIP3) over a bandwidth of 2.5 GHz to 3 GHz by

Koh Minghao; Grant A. Ellis; Teoh Chin Soon

2010-01-01

166

Silicon-germanium base heterojunction bipolar transistors by molecular beam epitaxy  

Microsoft Academic Search

The devices were fabricated using molecular-beam epitaxy (MBE), low-temperature processing, and germanium concentrations of 0, 6%, and 12%. The transistors demonstrate current gain, and show the expected increase in collector current as a result of reduced bandgap due to Ge incorporation in the base. For a 1000-Å base device containing 12% Ge, a six-times increase in collector current was measured

GARY L. PATTON; SUBRAMANIAN S. IYER; SYLVAIN L. DELAGE; S. Tiwari; J. M. C. Stork

1988-01-01

167

Controllable, low damage dry etching of heterojunction bipolar transistors and horizontal distributed Bragg reflector mirrors using an electron cyclotron resonance source  

NASA Astrophysics Data System (ADS)

Low damage, controllable dry etching of a variety of III-V materials is developed. The materials include GaInAs and AlInAs for fabrication of heterojunction bipolar transistors (HBTs), and GaAs and InP for horizontal distributed Bragg reflectors (HDBRs) and via holes. Etch characteristics including etch rate, sidewall profile, surface morphology, and etch induced damage must be controlled and readily modified for varying device requirements. Plasma etching is used to provide a directional component to the etch, but surface damage results from the bombardment of energetic ions needed for practical etch rates and profile control. To simultaneously meet the needs of profile control, high etch rates, and low damage, an electron cyclotron resonance source has been used. Electrical damage to GaInAs resulting from exposure to a Clsb2/Ar plasma has been studied using transmission lines. The specific contact resistivity (rhosb{c}) of Ti/Pt/Au on GaInAs was found to be more sensitive to surface damage than were Schottky diode characteristics. Defects generated by dry etching caused a reduction in rhosb{c} for n-GaInAs and an increase in rhosb{c} for p-GaInAs. The damage depth was ?6 nm at 50 W rf power and increased to ˜18 nm at 200 W rf power. Minimal surface damage was obtained when low rf power was used. After annealing, rhosb{c} for the p-GaInAs base layer was lower for optimized dry etching conditions compared to wet etching. This is due to the smoother surface morphology obtained after dry etching as measured by atomic force microscopy. The endpoint for HBT emitter etching was determined using optical emission spectroscopy (OES). Optical emission from atomic In at 410.2 nm and Ga at 417.2 nm have been detected with the strongest signal to background ratio. For abrupt junctions, <3 nm of the GaInAs base material is removed. For junctions with superlattice layers, endpoint can be obtained within 6 nm of the psp+ base region. Mass spectrometry has also been used to monitor P and As etch products. These signals have been studied for varying etch conditions and have been correlated to the etch rates. The ability of the mass spectrometer to detect the group V etch products coupled with the ability of OES to detect the group III elements allows for non-invasive real-time control of a variety of III-V material systems. The wafer temperature has been studied by using in situ fiberoptic thermometry which provides a direct measure of the wafer surface. A new device structure is proposed which allows the demonstration of high aspect ratio, high etch rate and selectivity, and low damage etching. The device is an HDBR Fabry-Perot interferometer, which consists of alternating layers of semiconductor and air. A highly anisotropic etch was developed to define plates 122 nm wide in InP and 59 nm wide in GaAs.

Thomas, Stephen, III

1997-09-01

168

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

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

169

Optimization of direct current performance in terahertz InGaAs/InP double-heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

As the dimensions of In0.53Ga0.47As/InP double-heterojunction bipolar transistors (DHBTs) scale for terahertz applications, the DC current (?) decreases. To improve the DC performance in such scaled devices, we analyze three modified HBT geometries: a HBT with a surface pulse-doped layer in the base, a HBT having this pulse-doped layer under the emitter junction and under the base contact, but with it removed by etching in the region between the base and emitter contacts, and a device, necessarily fabricated by regrowth, in which the pulsed doped layer is present under only the base contacts. Based on a drift-diffusion/recombination model, carrier transport in the DHBT base is simulated and the corresponding ? is computed using TCAD software. The structures with a pulse doped layer can attain ? = 31 ˜ 39 at 100 nm emitter width. The structures with a trench between the base contact and emitter show ? = 39 ˜ 54 at 100 nm emitter width. Finally, the structure with recessed base-emitter junction and regrown emitter demonstrate ? = 62-119 at 100 nm emitter width.

Chiang, Han-Wei; Rode, Johann C.; Choudhary, Prateek; Rodwell, Mark J. W.

2014-10-01

170

Fabrication of InAlAs/InGaAsSb/InGaAs double heterojunction bipolar transistors  

SciTech Connect

A trilevel resist system was employed to fabricate self-aligned, submicron emitter finger In0.52Al0.48As/ In0.42Ga0.58As0.77Sb0.23 / In0.53Ga0.47As double heterojunction bipolar transistors DHBTs. Selective wet-etchants were used to define the emitter fingers and to form an InGaAs guard-ring around the emitter fingers. Due to the low energy bandgap of the InGaAsSb base layer and type II base-collector junction, a low turn-on voltage of 0.38 V at 1 A/cm2 and a high dc current gain of 123.8 for a DHBT with a 0.658.65 m2 emitter area were obtained. A unity gain cutoff frequency fT of 260 GHz and a maximum oscillation frequency fmax of 485 GHz at JC =302 kA/cm2 were achieved.

Lo, C. F. [University of Florida; Ren, F. [University of Florida; Chang, C. Y. [University of Florida; Pearton, S. J. [University of Florida; Chen, Shu-han [National Central University, Taiwan; Chyi, Jen-inn [National Central University, Taiwan; Wang, Sheng-yu [National Central University, Taiwan; Kravchenko, Ivan I [ORNL

2011-01-01

171

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

NASA Astrophysics Data System (ADS)

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.

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

2004-05-01

172

0.25-?m-Emitter InP Heterojunction Bipolar Transistors with a Thin Ledge Structure  

NASA Astrophysics Data System (ADS)

This paper describes 0.25-?m-emitter InP heterojunction bipolar transistors (HBTs) with a thin ledge structure. The HBTs consist of a degenerately-doped n+-InGaAs/15-nm-thick undoped InP emitter, a 25-nm-thick p+-In0.53Ga0.47As base, and a 75-nm-thick In0.53Ga0.47As collector. The emitter enables fabrication of a 15-nm-thick ledge structure simply by wet etching the n+-InGaAs emitter. The emitter mesa and base metal were scaled down to 0.25 and 0.3 ?m, respectively. The fabricated HBT with a 0.25-?m emitter provides a current gain of 62 at a collector current density, Jc, of 10 mA/?m2. With the thin ledge structure, the current gain is virtually independent of emitter size and emitter-base spacing. The HBT also exhibits an ft of 442 GHz and an fmax of 214 GHz at a Jc of 12 mA/?m2. The results of bias-temperature stress tests show that base and collector currents are stable up to 1042 h at a Jc of 5 mA/?m2.

Norihide Kashio,; Kenji Kurishima,; Yoshino K. Fukai,; Minoru Ida,; Shoji Yamahata,

2010-04-01

173

0.25-µm-Emitter InP Heterojunction Bipolar Transistors with a Thin Ledge Structure  

NASA Astrophysics Data System (ADS)

This paper describes 0.25-µm-emitter InP heterojunction bipolar transistors (HBTs) with a thin ledge structure. The HBTs consist of a degenerately-doped n+-InGaAs/15-nm-thick undoped InP emitter, a 25-nm-thick p+-In0.53Ga0.47As base, and a 75-nm-thick In0.53Ga0.47As collector. The emitter enables fabrication of a 15-nm-thick ledge structure simply by wet etching the n+-InGaAs emitter. The emitter mesa and base metal were scaled down to 0.25 and 0.3 µm, respectively. The fabricated HBT with a 0.25-µm emitter provides a current gain of 62 at a collector current density, Jc, of 10 mA/µm2. With the thin ledge structure, the current gain is virtually independent of emitter size and emitter-base spacing. The HBT also exhibits an ft of 442 GHz and an fmax of 214 GHz at a Jc of 12 mA/µm2. The results of bias-temperature stress tests show that base and collector currents are stable up to 1042 h at a Jc of 5 mA/µm2.

Kashio, Norihide; Kurishima, Kenji; Fukai, Yoshino K.; Ida, Minoru; Yamahata, Shoji

2010-04-01

174

Variable-angle spectroscopic ellipsometry of InAlP native oxide dielectric layers for GaAs metal-oxide-semiconductor field effect transistor applications  

NASA Astrophysics Data System (ADS)

Variable angle spectroscopic ellipsometry models and data analysis have been developed to accurately determine the thickness of indium aluminum phosphide (InAlP) native oxide films used for the gate oxide in GaAs-based metal-oxide-semiconductor field effect transistor devices. The optical constants of the InAlP oxide, as well as InAlP and indium aluminum phosphide (InGaP) lattice matched to GaAs, have been determined by ellipsometry measurements using a photon energy range of 1.45 to 5.45 eV. Using the optical constants of InAlP and InAlP oxide, an ellipsometry-based model has been developed to characterize the oxidation kinetics of a thick partially oxidized InAlP epitaxial film grown on GaAs. The data indicate a delay in the full oxidation of In relative to Al as InAlP is fully oxidized. Excellent agreement between the thickness values determined by transmission electron microscopy imaging and by ellipsometric modeling validates the optical constants obtained. The ellipsometry material parameter models have also been extended to accurately fit the thickness of <100 Å InAlP oxides grown directly upon a multi-layer heterostructure for use as a transistor gate oxide. The InAlP oxide thicknesses determined by ellipsometry agree with those determined by electron microscopy to within 4%.

Yuan, Wangqing; Hall, D. C.

2013-03-01

175

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

PubMed

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. PMID:25902374

Martí, A; Luque, A

2015-01-01

176

Pure valley- and spin-entangled states in a MoS2-based bipolar transistor  

NASA Astrophysics Data System (ADS)

In this study, we show that the local Andreev reflection not only can be tuned largely by the type of the normal metal electrode, it also is related to the electrostatic potential in the superconductor region in a MoS2-based n (p ) -type metal/superconductor junction. In a MoS2-based n -type metal/n (p ) -type superconductor/p -type metal (n Sp ) transistor, nonlocal pure valley- and spin-entangled current can be tuned by the length and local gate voltage of a superconductor region. In particular, switching the quasiparticle type in both structures results in a series of intriguing features. Such an effect is not attainable in a graphene-based junction where the electron-hole symmetry enables the symmetry results to be observed. Besides, we have shown that the crossed Andreev reflection exhibits a maximum around ? /2 instead of the exponential decay behavior in conventional superconductors and a maximum around ? in the graphene material. The proposed straightforward experimental design and pure valley- and spin-entangled state can pave the way for a wider use in the entanglement based on material group-VI dichalcogenides.

Bai, Chunxu; Zou, Yonglian; Lou, Wen-Kai; Chang, Kai

2014-11-01

177

Si/Si(1-x)Ge(x) heterojunction bipolar transistors produced by limited reaction processing  

NASA Astrophysics Data System (ADS)

Si/Si(1-x)Ge(x) heterojunction transistors (HBTs) fabricated by a novel CVD technique are reported. A rapid thermal limited-reaction processing technique was used for the in situ growth of all three device layers, including a 20-mm Si(1-x)Ge(x) layer in the base. The highest current gains observed (beta = 400) were for an HBT with a base doping of 7 x 10 to the 18th/cu cm near the junction and a shallow As implant to form ohmic contacts and increase current gain. Ideal base currents were observed for over six decades of current, and the collector current remained ideal for nearly nine current decades starting at 1 pA. The bandgap difference between a p-type Si layer doped to 5 x 10 to the 17th/cu cm and an Si(0.69)Ge(0.31) base measured 0.27 eV. This value was deduced from the measurements of the temperature dependence of the base current and is in good agreement with published calculations for strained Si(1-x)Ge(x) layers on Si.

King, C. A.; Hoyt, Judy L.; Gronet, Chris M.; Gibbons, James F.; Scott, M. P.

1989-02-01

178

Bendable GaAs metal-semiconductor field-effect transistors formed with printed GaAs wire arrays on plastic substrates  

Microsoft Academic Search

Micro\\/nanowires of GaAs with integrated ohmic contacts have been prepared from bulk wafers by metal deposition and patterning, high-temperature annealing, and anisotropic chemical etching. These wires provide a unique type of material for high-performance devices that can be built directly on a wide range of unusual device substrates, such as plastic or paper. In particular, transfer printing organized arrays of

Yugang Sun; Seiyon Kim; Ilesanmi Adesida; John A. Rogers

2005-01-01

179

Collector-up aluminum gallium arsenide/gallium arsenide heterojunction bipolar transistors using oxidized aluminum arsenide for current confinement  

NASA Astrophysics Data System (ADS)

The discovery in 1990 that the wet thermal oxidation of AlAs can create a stable native oxide has added a new constituent, AlAs-oxide, to the AlGaAs/GaAs materials system. Native oxides of high Al mole-fraction AlGaAs are being used to confine electrical and/or optical fields in many types of electronic and optoelectronic structures with very promising results. Among these devices are collector-up heterojunction bipolar transistors (HBTs). Collector-up HBTs offer a means to reduce base-collector capacitance relative to their emitter-up counterparts, and thus to improve device performance. A novel method for fabricating collector-up AlGaAs/GaAs HBTs where an AlAs layer is inserted into the emitter layer and is oxidized in water vapor at 450sp°C has been developed. The resulting AlAs-oxide serves as a current confining layer that constricts collector current flow to the intrinsic portion of the device. Compared to previous methods of fabricating these devices, the process of converting AlAs into an insulator requires only one growth, and does not suffer from implant damage in the base. Because the lateral oxidation of AlAs is a process that proceeds at rates of microns per minute, one of the major challenges facing its implementation is the ability to accurately control the oxidation rate over the wafer, and from one wafer to the next. In the course of work on the oxidation of AlAs, a method to lithographically form lateral oxidation stop layers has been achieved. This technique utilizes impurity induced layer disordering (IILD) in heavily Si-doped buried planes, combined with selective surface patterning and thermal annealing, to create a lateral variation in the Al mole-fraction of the layer to be oxidized.

Massengale, Alan Ross

1998-12-01

180

LOW LEAKAGE CURRENT METAMORPHIC InGaAs/InP DHBTs WITH f and fmax > 268 GHz ON A GaAs SUBSTRATE  

E-print Network

LOW LEAKAGE CURRENT METAMORPHIC InGaAs/InP DHBTs WITH f and fmax > 268 GHz ON A GaAs SUBSTRATE Z-893-8044 Abstract Metamorphic InP/In0.53Ga0.47/InP double heterojunction bipolar transistors (mHBT) were grown etch and increase device yield. The metamorphic buffer layer is InP--employed because of its high

Rodwell, Mark J. W.

181

ELDRS in bipolar linear circuits: A review  

Microsoft Academic Search

Enhanced Low Dose Rate Sensitivity (ELDRS) in bipolar linear transistors was first identified in bipolar microcircuit transistors in 1991 and demonstrated in bipolar linear circuits in 1994. Since then it has been a major topic of research, characterization and analysis. Data compendia of low dose rate enhancement factors were presented in 1996, 2001 and 2008, identifying 30 unique widely used

Ronald L. Pease; Ronald D. Schrimpf; Daniel M. Fleetwood

2008-01-01

182

ELDRS in Bipolar Linear Circuits: A Review  

Microsoft Academic Search

Enhanced Low Dose Rate Sensitivity (ELDRS) in bipolar linear transistors was first identified in bipolar microcircuit transistors in 1991 and demonstrated in bipolar linear circuits in 1994. Since then it has been a major topic of research, characterization and analysis. Data compendia of low dose rate enhancement factors were presented in 1996, 2001 and 2008, identifying 30 unique widely used

Ronald L. Pease; Ronald D. Schrimpf; Daniel M. Fleetwood

2009-01-01

183

Germanium content and base doping level influence on extrinsic base resistance and dynamic performances of SiGe:C heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

We describe a reliable technique to separate the different contributions to the apparent base resistance (RB = RBx + X RBi) of silicon germanium carbon (SiGe:C) heterojunction bipolar transistors (HBTs). The extrinsic base resistance (RBx) is quantified using small-signal measurements. The base-collector junction distribution factor (X) and the intrinsic base resistance (RBi) are extracted from high frequency noise (MWN) measurements. This method is applied to five different SiGe:C HBTs varying in base doping level and germanium content. The results show that high doping levels improve high frequency noise performances while germanium gradient helps to maintain outstanding dynamic performances. This method could be used to elucidate the base technological configuration that ensures low noise together with remarkable dynamic performances in state-of-the-art SiGe:C HBTs.

Ramirez-Garcia, E.; Zerounian, N.; Aniel, F.; Valdez-Monroy, L. A.; Rodriguez-Mendez, L. M.; Valdez-Perez, D.; Galaz-Larios, M. C.; Enciso-Aguilar, M. A.

2014-09-01

184

Switching characteristics of a 4H-SiC insulated-gate bipolar transistor with interface defects up to the nonquasi-static regime  

NASA Astrophysics Data System (ADS)

The switching characteristics of a trench-type 4H-SiC insulated-gate bipolar transistor (IGBT) device with interface defects are analyzed up to the nonquasi-static (NQS) switching regime using reported interface density measurements and device simulation. Collector current degradation characterized by threshold voltage shift to higher gate voltages and reduction of current magnitude due to carrier trapping are observed under quasi-static (QS) simulation condition. At slow switching of the gate voltage, carrier trapping causes a hump in the transient current at the start of conduction. At very fast switching, the current hump is limited by the NQS effect which results to a reduced switching efficiency and increased on-resistance.

Pesic, Iliya; Navarro, Dondee; Fujinaga, Masato; Furui, Yoshiharu; Miura-Mattausch, Mitiko

2015-04-01

185

NpN-GaN/InxGa1-xN/GaN heterojunction bipolar transistor on free-standing GaN substrate  

NASA Astrophysics Data System (ADS)

Data and analysis are presented for NpN-GaN/InGaN/GaN double-heterojunction bipolar transistors (HBTs) grown and fabricated on a free-standing GaN (FS-GaN) substrate in comparison to that on a sapphire substrate to investigate the effect of dislocations in III-nitride HBT epitaxial structures. The performance characteristics of HBTs on FS-GaN exhibit a maximum collector current density of ˜12.3 kA/cm2, dc current gain of ˜90, and maximum differential gain of ˜120 without surface passivation, representing a substantial improvement over similar devices grown on sapphire. This is attributed to the reduction in threading dislocation density afforded by using a homoepitaxial growth on a high-crystalline-quality substrate. The minority carrier diffusion length increases significantly owing to not only a mitigated carrier trap effect via fewer dislocations, but also possibly reduced microscopic localized states.

Lochner, Zachary; Jin Kim, Hee; Lee, Yi-Che; Zhang, Yun; Choi, Suk; Shen, Shyh-Chiang; Doug Yoder, P.; Ryou, Jae-Hyun; Dupuis, Russell D.

2011-11-01

186

5 kW transversely excited atmospheric CO2 laser driven by a solid state exciter employing insulated gate bipolar transistors  

NASA Astrophysics Data System (ADS)

An average laser output power as high as 5 kW has been produced from a transversely excited atmospheric CO2 laser pumped with a new solid state exciter. The exciter providing a 100 J transfer energy consisted of a high voltage pulse generator and a two stage magnetic pulse compressor. A stack of new high power semiconductor switches, called insulated gate bipolar transistors, was employed for the main switch of the pulse generator. A sophisticated discharge head with the corona preionization behind a perforated anode was designed to realize fast and uniform gas flow in cooperation with acoustic dampers. The maximum average laser power of 4.6 kW was attained at a repetition rate of 550 pps with an overall efficiency as high as 10.5%. The maximum repetition rate achieved was 1.1 kpps, at which the resulting average laser power was 3.4 kW.

Hatanaka, Hidekazu; Midorikawa, Katsumi; Obara, Minoru; Tashiro, Hideo

1993-11-01

187

Common-base multi-finger submicron InGaAs/InP double heterojunction bipolar transistor with fmax of 305 GHz  

NASA Astrophysics Data System (ADS)

A layout of a common-base four-finger InGaAs/InP double heterostructure bipolar transistor (DHBT) has been designed and the corresponding DHBT has been fabricated successfully by using planarization technology. The area of each emitter finger was 1 × 15 ?m 2. The breakdown voltage was more than 7 V, the current could be more than 100 mA. The maximum output power can be more than 80 mW derived from the DC characteristics. The maximum oscillation frequency was as high as 305 GHz at IC = 50 mA and VCB = 1.5 V. The DHBT is thus promising for the medium power amplifier and voltage controlled oscillator (VCO) applications at W band and higher frequencies.

Jin, Z.; Su, Y.; Cheng, W.; Liu, X.; Xu, A.; Qi, M.

2008-11-01

188

A Cu-Metallized InGaP/GaAs Heterojunction Bipolar Transistor with Reliable Pd/Ge/Cu Ohmic Contact for Power Applications  

NASA Astrophysics Data System (ADS)

A Cu-metallized InGaP/GaAs heterojunction bipolar transistor (HBT) using a Pd/Ge/Cu n-type ohmic contact, a Pt/Ti/Pt/Cu p-type ohmic contact, and a Ti/Pt/Cu interconnect has been fabricated for power applications. The 4×20 µm2 HBT had an output power of 11.25 dBm with a power-added efficiency of 35.1%. After applying current-accelerated stress for 24 h, the current gain remained larger than 125. The device was also annealed at 200 °C for 24 h, and showed a slight decrease in output power from 10.06 to 9.83 dBm. The results demonstrated that reliable Cu metallization can be used for fabricating InGaP/GaAs HBTs for power applications.

Huang, Jui-Chien; Lin, Yueh-Chin; Tseng, Yu-Ling; Chen, Ke-Shian; Lu, Po-Chin; Lin, Mong-E.; Chang, Edward-Yi

2010-02-01

189

A Cu-Metallized InGaP/GaAs Heterojunction Bipolar Transistor with Reliable Pd/Ge/Cu Ohmic Contact for Power Applications  

NASA Astrophysics Data System (ADS)

A Cu-metallized InGaP/GaAs heterojunction bipolar transistor (HBT) using a Pd/Ge/Cu n-type ohmic contact, a Pt/Ti/Pt/Cu p-type ohmic contact, and a Ti/Pt/Cu interconnect has been fabricated for power applications. The 4× 20 ?m2 HBT had an output power of 11.25 dBm with a power-added efficiency of 35.1%. After applying current-accelerated stress for 24 h, the current gain remained larger than 125. The device was also annealed at 200 °C for 24 h, and showed a slight decrease in output power from 10.06 to 9.83 dBm. The results demonstrated that reliable Cu metallization can be used for fabricating InGaP/GaAs HBTs for power applications.

Jui-Chien Huang,; Yueh-Chin Lin,; Yu-Ling Tseng,; Ke-Shian Chen,; Po-Chin Lu,; Mong-E Lin,; Edward-Yi Chang,

2010-02-01

190

Growth of SiGe heterojunction bipolar transistor using Si 2H 6 gas and Ge solid sources molecular beam epitaxy  

NASA Astrophysics Data System (ADS)

N-p-n Si/SiGe/Si heterostructure has been grown by a disilane (Si 2H 6) gas and Ge solid sources molecular beam epitaxy system using phosphine (PH 3) and diborane (B 2H 6) as n- and p-type in situ doping sources, respectively. X-ray diffraction (XRD) and secondary ion mass spectroscopy (SIMS) measurements show that the grown heterostructure has a good quality, the boron doping is confined to the SiGe base layer, and the Ge has a trapezoidal profile. Post-growth P implantation was performed to prepare a good ohmic contact to the emitter. Heterojunction bipolar transistor (HBT) has been fabricated using the grown heterostructure and a common-emitter current gain of 75 and a cut-off frequency of 20 GHz at 300 K have been obtained.

Gao, F.; Huang, D. D.; Li, J. P.; Kong, M. Y.; Sun, D. Z.; Li, J. M.; Zeng, Y. P.; Lin, L. Y.

2001-03-01

191

A New Silicon-on-Insulator Lateral Insulated Gate Bipolar Transistor and Lateral Diode Employing the Separated Schottky Anode for a Power Integrated Circuit  

NASA Astrophysics Data System (ADS)

A new silicon-on-insulator (SOI) lateral insulated gate bipolar transistor (LIGBT) and lateral diode employing the separated Schottky anode (SSCA) is proposed and verified by the two dimensional numerical simulation based on experimental results. The Schottky barrier between the aluminum and lightly doped n-type silicon (Al/n-Si) of SSCA provides the potential difference between the n- anode contact and p+ anode to enhance the hole injection of p+ anode, which improves the forward current-voltage (I-V) characteristics. The anode region of SSCA-LIGBT is successfully decreased without negative differential resistance (NDR) regime and sacrificing the switching speed by employing contact. The SSCA structure applied to the diode also considerably improves the reverse recovery compared to the conventional p-i-n diode and reverse blocking capability compared to conventional Schottky diode.

Ji, In-Hwan; Choi, Young-Hwan; Ha, Min-Woo; Han, Min-Koo

2007-04-01

192

Silicon/silicon germanium heterostructures: Materials, physics, quantum functional devices and their integration with heterostructure bipolar transistors  

NASA Astrophysics Data System (ADS)

With the advent of the first transistor in 1947, the integrated circuit (IC) industry has rapidly expanded with the tremendous advances in the development of IC technology. The driving force in the evolution of IC technology is the reduction of transistor sizes. Without a doubt, transistor miniaturization will face fundamental physical limitations imposed by further dimensional scaling of silicon transistors in the near future. According to the 2004 International Technology Roadmap for Semiconductors (ITRS), the width of a gate electrode for complementary metal-oxide-semiconductor (CMOS) is projected to be a mere 7 nm by the end of 2018. No further solutions have been found. Since the 2001 ITRS, tunneling devices have been evaluated as an emerging technology to augment silicon CMOS. Transistor circuitry incorporating tunneling devices realized using III-V semiconductors has exhibited superior performance over its transistor-only counterparts. However, due to fundamental differences in material properties, such technology is not readily compatible with the mainstream platforms (>95% market share of semiconductors) of CMOS and HBT technologies. Recently, we demonstrated the successful monolithic integration of Si-based resonant interband tunnel diodes (RITDs) with CMOS and SiGe HBT, which makes them more attractive than III-V based tunnel diodes for system level integration. This dissertation is concerned with the development of quantum functional tunneling devices, RITDs, and high-speed transistors, HBTs, using Si/SiGe heterostructures as well as material growth and electrical properties of Si/SiGe heterostructures. Emphasis is placed on the development of Si/SiGe-based RITDs, HBTs, and their monolithic integration for 3-terminal negative differential resistance (NDR) devices. The operating principles of Si-based RITDs and the integration of RITD with HBT are also discussed.

Chung, Sung-Yong

193

PH-315 A. La Rosa TRANSISTORS and  

E-print Network

PH-315 A. La Rosa TRANSISTORS and TRANSISTOR AMPLIFIERS I. PURPOSE To familiarize with the characteristics of transistors, how to properly implement its DC bias, and illustrate its application as small signal amplifiers. The bipolar junction transistor as well as the field effect transistor

194

ULTRAHIGH-SPEED DIPOLAR TRANSISTORS  

E-print Network

ULTRAHIGH-SPEED DIPOLAR TRANSISTORS Understanding nonequilibrium electron transport in Ill-V compound semiconductors has helped in the development of the fastest bipolar transistors. A. F. J. Levi, R. N. Noltenburg, Y. K. Chen and M. B. Panish The invention of the transistor in the late 1940s has had

Levi, Anthony F. J.

195

Fabrication and Characterization of Self-aligned InAlAs/InGaAsSb/InGaAs Double Heterojunction Bipolar Transistors  

SciTech Connect

A trilevel resist system was employed to fabricate self-aligned, submicron emitter finger In0.52Al0.48As/In0.42Ga0.58As0.77Sb0.23/ In0.53Ga0.47As double heterojunction bipolar transistors (DHBTs). Selective wet-etchants were used to define the emitter fingers and to form an InGaAs guard-ring around the emitter fingers. Due to the low energy bandgap of the InGaAsSb base layer and type II base-collector junction, a low turn-on voltage of 0.38 V at 1 A/cm2 and a high dc current gain of 123.8 for a DHBT with a 0.65 8.65 m2 emitter area were obtained. A unity gain cut-off frequency (fT) of 260 GHz and a maximum oscillation frequency (fmax) of 485 GHz at JC = 302 kA/cm2 were achieved.

Lo, C. F. [University of Florida; Chang, C. Y. [University of Florida; Chen, Shu-han [National Central University, Taiwan; Wang, Sheng-yu [National Central University, Taiwan; Chyi, Jen-inn [National Central University, Taiwan; Kravchenko, Ivan I [ORNL; Pearton, S. J. [University of Florida; Ren, F. [University of Florida

2011-01-01

196

Microstructural analysis of a Au/Pt/Pd/Zn ohmic contact to an AlGaAs/GaAs heterojunction bipolar transistor  

NASA Astrophysics Data System (ADS)

Gold-based ohmic contacts, incorporating Pt, Pd, and Zn layers, to AIGaAs/GaAs heterojunction bipolar transistors (HBTs) have been characterized using transmission electron microscopy (TEM). The metallization was deposited onto a 30 nm graded emitter layer of n-type AlxGa1-xAs, which was on a 30 nm emitter layer of n-type Al0.3Ga0.7As, with the aim of contacting the underlying 80 nm thick graded base layer of p-type AlxGa1-xAs. Metal layers were deposited sequentially using electron beam evaporation and the resultant metallizations were annealed at temperatures ranging from 250-500°C for up to several minutes. A minimum contact resistance of ?8.5 × 10-7 ?-cm2 was achieved, which corresponded to the decomposition of ternary phases at the metallization/semiconductor interface, to binary phases, i.e., PdGa and PtAs2. Long term stability tests were done on the optimum contacts. Anneals at 270°C for up to four weeks in duration produced virtually no change in microstructure, with the exception of some outward diffusion of Ga and As.

Jian, P.; Ivey, D. G.; Eicher, S.; Lester, T. P.

1996-09-01

197

Novel Metal-Sulfur-Based Air-Stable Passivation of GaAs with Very Low Surface State Densities  

SciTech Connect

A new air-stable electronic surface passivation for GaAs and other III-V compound semiconductors that employs sulfur and a suitable metal ion, e.g., Zn, and that is robust towards plasma dielectric deposition has been developed. Initial improvements in photoluminescence are twice that of S-only treatments and have been preserved for >11 months with SiO{sub x}N{sub y} dielectric encapsulation. Photoluminescence and X-ray photoelectron spectroscopies indicate that the passivation consists of two major components with one being stable for >2 years in air. This process improves heterojunction bipolar transistor current gain for both large and small area devices.

Ashby, Carol I.H.; Baca, Albert G.; Chang, P.-C; Hafich, M.J.; Hammons, B.E.; Zavadil, Kevin R.

1999-08-09

198

Gallium arsenide-gallium nitride wafer fusion and the n-aluminum gallium arsenide/p-gallium arsenide/n-gallium nitride double heterojunction bipolar transistor  

NASA Astrophysics Data System (ADS)

This dissertation describes the n-AlGaAs/p-GaAs/n-GaN heterojunction bipolar transistor (HBT), the first transistor formed via wafer fusion. The fusion process was developed as a way to combine lattice-mismatched materials for high-performance electronic devices, not obtainable via conventional all-epitaxial formation methods. Despite the many challenges of wafer fusion, successful transistors were demonstrated and improved, via the optimization of material structure and fusion process conditions. Thus, this project demonstrated the integration of disparate device materials, chosen for their optimal electronic properties, unrestricted by the conventional (and very limiting) requirement of lattice-matching. By combining an AlGaAs-GaAs emitter-base with a GaN collector, the HBT benefited from the high breakdown voltage of GaN, and from the high emitter injection efficiency and low base transit time of AlGaAs-GaAs. Because the GaAs-GaN lattice mismatch precluded an all-epitaxial formation of the HBT, the GaAs-GaN heterostructure was formed via fusion. This project began with the development of a fusion process that formed mechanically robust and electrically active GaAs-GaN heterojunctions. During the correlation of device electrical performance with a systematic variation of fusion conditions over a wide range (500--750°C, 0.5--2hours), a mid-range fusion temperature was found to induce optimal HBT electrical performance. Transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS) were used to assess possible reasons for the variations observed in device electrical performance. Fusion process conditions were correlated with electrical (I-V), structural (TEM), and chemical (SIMS) analyses of the resulting heterojunctions, in order to investigate the trade-off between increased interfacial disorder (TEM) with low fusion temperature and increased diffusion (SIMS) with high fusion temperature. The best do device results (IC ˜ 2.9 kA/cm2 and beta ˜ 3.5, at VCE = 20V and IB = 10mA) were obtained with an HBT formed via fusion at 600°C for 1 hour, with an optimized base-collector design. This was quite an improvement, as compared to an HBT with a simpler base-collector structure, also fused at 600°C for 1 hour (IC ˜ 0.83 kA/cm2 and beta ˜ 0.89, at VCE = 20V and IB = 10mA). Fused AlGaAs-GaAs-GaAs HBTs were compared to fused AlGaAs-GaAs-GaN HBTs, demonstrating that the use of a wider bandgap collector (Eg,GaN > Eg,GaAs) did indeed improve HBT performance at high applied voltages, as desired for high-power applications.

Estrada, Sarah M.

199

IEEE ELECTRON DEVICE LETTERS, VOL. 18, NO. 11, NOVEMBER 1997 553 High InP Double Heterojunction Bipolar  

E-print Network

Bipolar Transistors with Chirped InGaAs/InP Superlattice Base­Collector Junction Grown by CBE Kyounghoon- erojunction Bipolar Transistors (DHBT's) with a chirped In- GaAs/InP superlattice B­C junction grown by CBE -emitter DHBT. I. INTRODUCTION RECENTLY, InP-based heterojunction bipolar transistors have demonstrated

Yang, Kyounghoon

200

Bipolar Disorder  

MedlinePLUS

... this brochure to find out more. What is bipolar disorder? Bipolar disorder is a serious brain illness. ... get better and lead successful lives. Who develops bipolar disorder? Anyone can develop bipolar disorder. It often ...

201

Heavily carbon-doped InGaP\\/GaAs HBT's with buried polycrystalline GaAs under the base electrode  

Microsoft Academic Search

This paper describes a new approach to fabricating InGaP\\/GaAs heterojunction bipolar transistors (HBT's) with a high cutoff frequency (fT), high maximum oscillation frequency (fmax), and low external collector capacitance (Cbc). To attain a high fT and fmax, a heavy carbon-doping (1.3×1020 cm-3) technique was used with a thin (30-nm-thick) GaAs base layer, while for low Cbc, low-temperature gas-source molecular-beam epitaxial

Kazuhiro Mochizuki; Kiyoshi Ouchi; Kohji Hirata; Tohru Oka; Tomonori Tanoue

1998-01-01

202

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

NASA Technical Reports Server (NTRS)

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 structures and map out the spatial sensitivities using the Sandia Focused Heavy Ion Microprobe Facility s Ion Beam Induced Charge Collection (IBICC) technique. Combining the two data sets offers insights into the charge collection mechanisms responsible for circuit level response and provides the first insights into the SEE characteristics of this latest version of IBM s commercial SiGe process.

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

203

Response of advanced bipolar processes to ionizing radiation  

Microsoft Academic Search

Ionizing radiation induced gain degradation in microcircuit bipolar polysilicon and crystalline emitter transistors is investigated. In this work, 60Co irradiation testing was performed on bipolar test structures. The effects of collector bias, dose rate, and anneal temperature are discussed. Major differences in the radiation response of polysilicon emitter transistors are demonstrated as a function of dose rate. The worst-case gain

Edward W. Enlow; Ronald L. Pease; William Combs; Ron D. Schrimpf; R. Nathan Nowlin

1991-01-01

204

Realising high-current gain p-n-p transistors using a novel surface accumulation layer transistor  

E-print Network

Realising high-current gain p-n-p transistors using a novel surface accumulation layer transistor accumulation layer transistor (SALTran) on SOI, which uses the concept of surface accumulation of holes near of the previously published conventional p-n-p lateral bipolar transistor (LBT) structure. From the simulation

Kumar, M. Jagadesh

205

IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 52, NO. 11, NOVEMBER 2005 2489 Analysis of the Kirk Effect in Silicon-Based Bipolar  

E-print Network

Effect in Silicon-Based Bipolar Transistors With a Nonuniform Collector Profile Raymond J. E. Hueting- icon-based bipolar transistors (BJTs) with a nonuniform collector profile. We show that, for any for optimizing future BJTs. Index Terms--Heterojunction bipolar transistors (HBTs), high- frequency (HF

Technische Universiteit Delft

206

Bipolar Disorder  

MedlinePLUS

What Is Bipolar Disorder? Bipolar disorders are one of several medical conditions called depressive disorders. Depressive disorders affect the way a ... for doctors to diagnose. Back Continue What Causes Bipolar Disorder? Doctors and scientists don't know the ...

207

Bipolar Disorder  

MedlinePLUS

Bipolar Disorder FACT SHEET NAMI • The National Alliance on Mental Illness • 1 (800) 950-NAMI • www.nami. ... Suite 100, Arlington, Va. 22203 1 What is bipolar disorder? Bipolar disorder is a persistent illness with ...

208

A new type of transistor: CBT  

Microsoft Academic Search

A transistor called the channel-base transistor (CBT), which is constructed by making channels through the base of the conventional bipolar junction transistors (BJTs), is proposed. In principle, a CBT can be treated as a combination of a BJT and a normally-off junction-type field-effect transistor (E-JFET). Silicon planer CBTs have been fabricated with BJTs on the same wafer for comparison. The

Bao-Wei Kang; Wei Zhao; Li-Min Dong; Yan Situ

1993-01-01

209

Implementation and operational investigations of bipolar gate drivers  

E-print Network

Implementation and operational investigations of bipolar gate drivers Jean-Christophe CREBIER with the investigation of simple implementation and design of bipolar gate driver for high side power transistor control. Bipolar gate signals are usually preferred for high switching dynamic control and power device shielding

Boyer, Edmond

210

Low phase noise GaAs HBT VCO in Ka-band  

NASA Astrophysics Data System (ADS)

Design and fabrication of a Ka-band voltage-controlled oscillator (VCO) using commercially available 1-?m GaAs heterojunction bipolar transistor technology is presented. A fully differential common-emitter configuration with a symmetric capacitance with a symmetric inductance tank structure is employed to reduce the phase noise of the VCO, and a novel ?-feedback network is applied to compensate for the 180° phase shift. The on-wafer test shows that the VCO exhibits a phase noise of ?96.47 dBc/Hz at a 1 MHz offset and presents a tuning range from 28.312 to 28.695 GHz. The overall dc current consumption of the VCO is 18 mA with a supply voltage of ?6 V The chip area of the VCO is 0.7 × 0.7 mm2.

Ting, Yan; Yuming, Zhang; Hongliang, Lü; Yimen, Zhang; Yue, Wu; Yifeng, Liu

2015-02-01

211

IEEE BCTM 4.2 Study ofbipolar transistor matching at high current level with various  

E-print Network

IEEE BCTM 4.2 Study ofbipolar transistor matching at high current level with various test-mail: samuel.bordez@st.com, Tel: +33 4 38 92 29 30 Abstract - Matching of bipolar transistors has been. INTRODUCTION Bipolar transistor matching is often described in a medium current zone. Yet, results at high

McNeill, John A.

212

Rapid thermal anneal in InP, GaAs and GaAs/GaAlAs  

NASA Astrophysics Data System (ADS)

Ion implantation in semiconductors provides a doping technique with several advantages over more conventional doping methods and is now extensively used for device applications, e.g. field effect transistors (MESFET GaAs, MIS (InP), GaAs/GaAlAs heterojunction bipolar transistors (HBT). Because of the lattice disorder produced by the implantation, the dopant must be made electrically active by a postimplant anneal. As the device performances are very dependent on its electrical characteristics, the anneal is a very important stage of the process. Rapid anneal is known to provide less exodiffusion and less induffusion of impurities compared to conventional furnace anneal, so this technique has been used in this work to activate an n-type dopant (Si) in InP and a p-type dopant (Mg) in GaAs and GaAs/GaAIAs. These two ions have been chosen to realize implanted MIS InP and the base contacts for GaAs/GaAlAs HBTs. The experimental conditions to obtain the maximum electrical activity in these two cases will be detailed. For example, although we have not been able to obtain a flat profile in Mg + implanted GaAs/GaAlAs heterostructure by conventional thermal anneal, rapid thermal anneal gives a flat hole profile over a depth of 0.5 ?m with a concentration of 1 x 10 19 cm -3.

Descouts, B.; Duhamel, N.; Godefroy, S.; Krauz, P.

213

GaAs optoelectronic neuron arrays  

NASA Technical Reports Server (NTRS)

A simple optoelectronic circuit integrated monolithically in GaAs to implement sigmoidal neuron responses is presented. The circuit integrates a light-emitting diode with one or two transistors and one or two photodetectors. The design considerations for building arrays with densities of up to 10,000/sq cm are discussed.

Lin, Steven; Grot, Annette; Luo, Jiafu; Psaltis, Demetri

1993-01-01

214

Bipolar disorder  

MedlinePLUS

Bipolar disorder is a condition in which a person has periods of depression and periods of being extremely ... Bipolar disorder affects men and women equally. It usually starts between ages 15 and 25. The exact cause ...

215

Bipolar Disorder  

MedlinePLUS

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

216

GaAs Electronic Devices  

Microsoft Academic Search

Unipolar, bipolar and resonant tunnelling transistors based on III-V materials are competing for various applications in high speed electronic systems. The principles of operation are described briefly. The examination of equivalent circuits shows that parasitic elements are limiting the performance of the most advanced devices. The state of the art is discussed by presenting data for low-noise-amplifiers, high power amplifiers,

W. Kellner

1989-01-01

217

Ultrahigh doping of GaAs by carbon during metalorganic molecular beam epitaxy  

NASA Astrophysics Data System (ADS)

Recent advances in heterostructure bipolar transistor technology have created a need for p-type doping at levels ?1020 cm-3. Furthermore, such levels may eliminate the need for alloying during ohmic contact formation. We have achieved p-type doping levels as high as 5×1020 cm-3 using an unconventional dopant, C, derived from the gaseous source chemical, trimethylgallium (TMG), during metalorganic molecular beam epitaxial (MOMBE) growth of GaAs. We have controllably achieved doping levels between 1019 and 5×1020 cm-3 by diluting the TMG flow with another metalorganic, triethylgallium (TEG). By utilizing the so-called ?-doping or atomic planar doping method we have also been able to grow C-doped spikes with hole concentrations as high as 7×1019 cm-3, with a full width at half maximum of ˜50 Å at 300 K. This doping level is the highest yet reported for planar doping, and the narrow width indicates that the C atoms are restricted to one or two atomic planes. By switching out the TMG, and switching in the TEG to continue the growth of C-free GaAs we have grown sandwich-type structures with C levels of 1020 cm-3, which fall off within 210 Å to C levels of <1017 cm-3. High-temperature annealing of such structures reveals a C diffusion coefficient of ?10-16 cm2 s-1 at 950 °C, in agreement with other reports. This is at least three orders of magnitude less than for the other conventional p-type dopants, Be and Zn. Finally, we report the presence of strain in the highly C-doped layers, detected by x-ray diffraction. The lattice constant obtained corresponds roughly to that calculated by assuming a Vegard's law mixture of GaAs and 0.7% GaC. This distortion of the GaAs lattice has not been previously measured.

Abernathy, C. R.; Pearton, S. J.; Caruso, R.; Ren, F.; Kovalchik, J.

1989-10-01

218

Metamorphosis of the transistor into a laser  

NASA Astrophysics Data System (ADS)

Based on the invention and operation of the transistor, the alloy diode laser, the quantum-well diode laser and the high-speed heterojunction bipolar transistor (HBT), we have invented and realized now a transistor laser (TL). The transistor laser is a three-terminal technology providing coupling and the coherent light emission in the transistor. The quantum-well (QW) heterojunction bipolar transistor laser, inherently a fast switching device, operates by transporting a small minority base charge density ˜1016 \\text{cm}-3 over a nanoscale base thickness (<900 \\text{A}) in picoseconds. The TL, owing to its fast recombination speed, its unique three-terminal configuration, and complementary nature of its optical and electrical collector output signals, enables resonance-free base current and collector voltage modulation. It is a compact source of electro-optical applications such as nonlinear signal mixing, frequency multiplication, negative feedback, and optoelectronics logic gates.

Feng, M.; Holonyak, N., Jr.

2015-01-01

219

IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 50, NO. 3, MARCH 2003 645 Transistor Design and Application Considerations for  

E-print Network

IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 50, NO. 3, MARCH 2003 645 Transistor Design, and Seshadri Subbanna, Member, IEEE Invited Paper Abstract--SiGe HBT transistors achieving over 200 GHz and MAX--BiCMOS integrated circuits, bipolar transistors, heterojunctions, semiconductor devices. I. INTRODUCTION BIPOLAR

Rieh, Jae-Sung

220

A simple method for forming compositionally graded InxGa1?xAs1?ySby base of double-heterojunction bipolar transistors modulating CBr4-doping-precursor flow in metalorganic chemical vapor deposition  

NASA Astrophysics Data System (ADS)

We studied a CBr4-flow-modulation method as a way of simplifying the formation of a compositionally graded InxGa1?xAs1?ySby base of InP-based heterojunction bipolar transistors (HBTs) by metalorganic chemical vapor deposition. An investigation of C-doping in InxGa1?xAs1?ySby revealed that In and Sb contents decrease as the supply ratio of CBr4 to group-III (RC) increases. We fabricated 0.25-µm-emitter HBTs with a compositionally graded InxGa1?xAs1?ySby base formed by varying RC at constant group-III, group-V, and V/III ratios. By this method, we obtained higher current-gain cut-off frequency (504 GHz) and maximum-oscillation frequency (328 GHz) than those of uniform-InxGa1?xAs1?ySby-base HBTs with the same base/collector thicknesses.

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

2014-11-01

221

Simulating Single-Event Upsets in Bipolar RAM's  

NASA Technical Reports Server (NTRS)

Simulation technique saves testing. Uses interactive version of SPICE (Simulation Program with Integrated Circuit Emphasis). Device and subcircuit models available in software used to construct macromodel for an integrated bipolar transistor. Time-dependent current generators placed inside transistor macromodel to simulate charge collection from ion track. Significant finding of experiments is standard design practice of reducing power in unaddressed bipolar RAM cell increases sensitivity of cell to single-event upsets.

Zoutendyk, J. A.

1986-01-01

222

Optimization of lateral double-diffused MOS transistors in 0.18 µm bipolar-CMOS-DMOS technology for wide-voltage applications  

NASA Astrophysics Data System (ADS)

The reduced-surface-field-type lateral double-diffused MOS (LDMOS) structure, which is the key element used in the power device of the bipolar-CMOS-DMOS (BCD) process, was optimized for a wide voltage range of 20-60 V class in the 0.18 µm BCD process. The on-state resistance (Ron) characteristics to the drain-to-source breakdown voltage (BVdss) have been improved by optimizing the n-drift conditions and related design rules and the reliable safe operating area (SOA) of the device has also been secured for the 20-30 V class LDMOS device. In order to optimize the 40-60 V class LDMOS device, the n-drift drain buffer and low voltage-threshold voltage for the p-channel device implant were introduced and the reliable SOA was obtained while the excellent Ron characteristics showed up to the 60 V class. The final trade-off (Ron versus BVdss) characteristics of the LDMOS fabricated under the newly proposed 0.18 µm BCD process have shown competitive characteristics in the wide voltage range for the various applications.

Choi, Y. O.; Kim, S. Y.

2010-11-01

223

Bipolar Disorder.  

ERIC Educational Resources Information Center

Bipolar disorder, a brain disorder that causes unusual shifts in a person's mood, affects approximately one percent of the population. It commonly occurs in late adolescence and is often unrecognized. The diagnosis of bipolar disorder is made on the basis of symptoms, course of illness, and when possible, family history. Thoughts of suicide are…

Spearing, Melissa

224

Characterization of enhanced low dose rate sensitivity (ELDRS) effects using Gated Lateral PNP transistor structures  

Microsoft Academic Search

The high and low dose rate responses of bipolar transistors in a bipolar linear circuit process technology have been studied with specially designed gated lateral pnp test transistors that allow for the extraction of the oxide trapped charge (Not) and interface trap (Nit) densities. The buildup of Not and Nit with total dose is investigated as a function of the

Ronald L. Pease; Dale G. Platteter; G. W. Dunham; J. E. Seiler; H. J. Barnaby; R. D. Schrimpf; Marty R. Shaneyfelt; M. C. Maher; R. N. Nowlin

2004-01-01

225

Low-noise gallium-arsenide field-effect transistor preamplifiers for stochastic beam-cooling systems  

SciTech Connect

The present noise performance, bandwidth capability and gain stability of bipolar and field-effect transistors, parametric amplifier, Schottky diode mixer and maser are summarized and compared in the 100 MHz to 40 GHz frequency range for stochastic beam cooling systems. Stability factor of GaAs FET's as a function of ambient temperature is presented and discussed. Performance data of several low-noise wide-band cryogenically cooled preamplifiers are presented including one with a noise figure of 0.35 dB over a bandwidth range of 150 to 500 MHz operating at ambient temperature of 20/sup 0/K. Also, data are given on a broadband 1 to 2 GHz preamplifier having a noise figure of approximately 0.2 dB. The gain, operating noise temperature, stability, gain nonuniformity and phase-shift as function of frequency of interest for beam cooling systems are discussed.

Leskovar, B.; Lo, C.C.

1983-03-01

226

Cryogenic measurements of aerojet GaAs n-JFETs  

NASA Technical Reports Server (NTRS)

The spectral noise characteristics of Aerojet gallium arsenide (GaAs) junction field effect transistors (JFET's) have been investigated down to liquid-helium temperatures. Noise characterization was performed with the field effect transistor (FET) in the floating-gate mode, in the grounded-gate mode to determine the lowest noise readings possible, and with an extrinsic silicon photodetector at various detector bias voltages to determine optimum operating conditions. The measurements indicate that the Aerojet GaAs JFET is a quiet and stable device at liquid helium temperatures. Hence, it can be considered a readout line driver or infrared detector preamplifier as well as a host of other cryogenic applications. Its noise performance is superior to silicon (Si) metal oxide semiconductor field effect transistor (MOSFET's) operating at liquid helium temperatures, and is equal to the best Si n channel junction field effect transistor (n-JFET's) operating at 300 K.

Goebel, John H.; Weber, Theodore T.

1993-01-01

227

GaAs optoelectronic neuron arrays  

Microsoft Academic Search

A simple optoelectronic circuit integrated monolithically in GaAs to implement sigmoidal neuron responses is presented. The circuit integrates a light-emitting diode with one or two transistors and one or two photodetectors. The design considerations for building arrays with densities of up to o4 cm- 2 are discussed. The two components required for the implementa- tion of a neural network are

Steven Lin; Annette Grot; Jiafu Luo; Demetri Psaltis

1992-01-01

228

Bipolar Disorder  

MedlinePLUS

... illnesses with similar symptoms such as depression and schizophrenia to identify genetic differences that may increase a ... symptoms that overlap somewhat with bipolar disorder and schizophrenia. This suggests that the common pattern of brain ...

229

Bipolar battery  

DOEpatents

A bipolar battery having a plurality of cells. The bipolar battery includes: a negative electrode; a positive electrode and a separator element disposed between the negative electrode and the positive electrode, the separator element electrically insulating the electrodes from one another; an electrolyte disposed within at least one of the negative electrode, the positive electrode and the separator element; and an electrode containment structure including a cup-like electrode holder.

Kaun, Thomas D. (New Lenox, IL)

1992-01-01

230

Metamorphic materials for indium arsenide transistors  

NASA Astrophysics Data System (ADS)

To improve on both the high frequency and low-power aspects of the III-V semiconductor microwave transistor (by definition, the microwave transistor operates at frequencies above 1 GHz), InAs or a related high indium content alloy is incorporated in the base layer of the heterojunction bipolar transistor (HBT) and the channel layer of the high electron mobility transistor (HEMT). These devices must be fabricated on a semi-insulating (SI) substrate for effective microwave performance which becomes a challenge for the high indium content structures due to the large lattice mismatch with the SI substrates that are commercially available (InP and GaAs). A virtual substrate is engineered which has the desired semi-insulating bulk properties and large lattice parameter template for the epitaxial growth of InAs-based microwave devices. The HBT device, a minority carrier structure, requires a low defect density in the device. This is accomplished with a 0.9 mum compositionally graded InxAl1-xAs (0.52GaAs substrate, which has the advantage of a smoother surface morphology and high resistivity. The large amount of strain (8%) introduced at the interface results in a rhot that decreases linearly with buffer thickness. AlSb CCBLs grown to 0.65, 1.27, and 1.72 mum contain 7.7 x 108, 3.1 x 109, and 5.4 x 109 cm-2 threading dislocations, respectively, in the InAs channels of the HEMT devices. The gate leakage current in the device degrades by a factor of 3 from the low to the high rhot samples. No trend is found with room temperature mobility and rhot , however at low temperatures there is a decrease in mobility with high rho t. The dislocation inhibited mobility is modeled analytically and agrees with experimental results. An alternate approach to creating a narrow bandgap, large lattice parameter virtual substrate is wafer bonding coupled with hydrogen ion implantation and exfoliation. This technique is investigated for metamorphic InAs semiconductors. Key factors taken into consideration are the high diffusivity of hydrogen in the low melting temperature materials and the high density of dislocations in the metamorphic materials. Annealing of the ion implanted metamorphic InAs at 150°C for 10 minutes causes interstitial hydrogen to diffuse away from the implanted region and settle at low energy sites - strained regions around dislocations. Uniform surface blistering is produced at the implantation depth after 5 hours of annealing at 75°C. This effect is explained by the increased diffusivity of hydrogen at higher temperatures.

Noori, Atif M.

231

Types of Bipolar Disorder  

MedlinePLUS

Types of Bipolar Disorder There are several kinds of bipolar disorder. Each kind is defined by the length, frequency and pattern of episodes of mania and depression. Bipolar I Disorder Bipolar I disorder is characterized by ...

232

Characterizing charge trapping in microwave transistors  

Microsoft Academic Search

This paper looks at the problems associated with pulsed testing of GaN and GaAs HEMTs and its use in examining the charging and discharging times of the various traps that affect conduction. A particular problem is that the RF behaviour of these transistors varies with the state of charge of the traps. This is a concern for a large class

James G. Rathmell; Anthony E. Parker

233

Charge collection in GaAs MESFET circuits using a high energy microbeam  

Microsoft Academic Search

The mechanisms responsible for single event upsets can be studied more realistically in transistors that are part of an integrated test circuit than in single isolated test transistors with fixed biases on all the nodes. Both energetic, heavy ions and focused, pulsed laser light were used to generate transient voltages at a number of different nodes in a GaAs MESFET

S. Buchner; A. B. Campbell; T. Weatherford; A. Knudson; P. McDonald; D. McMorrow; B. Fischer; S. Metzger; M. Schloegl

1996-01-01

234

Method for double-sided processing of thin film transistors  

DOEpatents

This invention provides methods for fabricating thin film electronic devices with both front- and backside processing capabilities. Using these methods, high temperature processing steps may be carried out during both frontside and backside processing. The methods are well-suited for fabricating back-gate and double-gate field effect transistors, double-sided bipolar transistors and 3D integrated circuits.

Yuan, Hao-Chih (Madison, WI); Wang, Guogong (Madison, WI); Eriksson, Mark A. (Madison, WI); Evans, Paul G. (Madison, WI); Lagally, Max G. (Madison, WI); Ma, Zhenqiang (Middleton, WI)

2008-04-08

235

Developing Low-Noise GaAs JFETs For Cryogenic Operation  

NASA Technical Reports Server (NTRS)

Report discusses aspects of effort to develop low-noise, low-gate-leakage gallium arsenide-based junction field-effect transistors (JFETs) for operation at temperature of about 4 K as readout amplifiers and multiplexing devices for infrared-imaging devices. Transistors needed to replace silicon transistors, relatively noisy at 4 K. Report briefly discusses basic physical principles of JFETs and describes continuing process of optimization of designs of GaAs JFETs for cryogenic operation.

Cunningham, Thomas J.

1995-01-01

236

The 20 GHz power GaAs FET development  

NASA Technical Reports Server (NTRS)

The development of power Field Effect Transistors (FET) operating in the 20 GHz frequency band is described. The major efforts include GaAs FET device development (both 1 W and 2 W devices), and the development of an amplifier module using these devices.

Crandell, M.

1986-01-01

237

Magnetic vortex based transistor operations.  

PubMed

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

Kumar, D; Barman, S; Barman, A

2014-01-01

238

Magnetic Vortex Based Transistor Operations  

PubMed Central

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

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

2014-01-01

239

Forward-bias tunneling - A limitation to bipolar device scaling  

NASA Technical Reports Server (NTRS)

Forward-bias tunneling is observed in heavily doped p-n junctions of bipolar transistors. A simple phenomenological model suitable to incorporation in device codes is developed. The model identifies as key parameters the space-charge-region (SCR) thickness at zero bias and the reduced doping level at its edges which can both be obtained from CV characteristics. This tunneling mechanism may limit the maximum gain achievable from scaled bipolar devices.

Del Alamo, Jesus A.; Swanson, Richard M.

1986-01-01

240

Bipolar Disorder Among Adults  

MedlinePLUS

... News About Us Home > Health & Education > Statistics > Prevalence Bipolar Disorder Among Adults Statistics Home Prevalence Serious Mental ... Disorder Among Adults Any Mood Disorder in Children Bipolar Disorder Among Adults Bipolar Disorder Among Children Dysthymic ...

241

technologie transistor.  

E-print Network

�léments de technologie Les circuits intégrées c-MOS. L'élément de base est le transistor. Deux types de transistors complémentaires n-MOS et p-MOS. Avantages des c-MOS : #21; très grande intégration des impuretés. - plus récement : bombardement ionique. 2 #12; Transistor n-MOS (Metal

Hivert, Florent

242

positions): transistor,  

E-print Network

) . Biology & Medicine ­ 4 (psychoanalysis, penicillin, DNA, polio) . Physics & Astronomy ­ 3 (Einstein, Fermi, transistor, plastic, WWW) . Biology & Medicine ­ 4 (psychoanalysis, penicillin, DNA, polio) . Physics

Artemov, Sergei N.

243

Concept of Quasi-Capacitive Tapping of Bipolar Voltage-Controlled Oscillators  

E-print Network

, bipolar transistors often have limited use in the design of VCO's, due to a limited voltage swing across and give up, almost native in the design of fully integrated VCO's, CMOS technology. However transconductance for the same operating point, a bipolar VCO could lead to a high-performance design. The technique

Serdijn, Wouter A.

244

2364 IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 53, NO. 9, SEPTEMBER 2006 New Schottky-Gate Bipolar-Mode Field-Effect  

E-print Network

-Gate Bipolar-Mode Field-Effect Transistor (SBMFET): Design and Analysis Using Two-Dimensional Simulation M. Jagadesh Kumar, Senior Member, IEEE, and Harsh Bahl Abstract--A new Schottky-gate bipolar-mode field importance in medium-power high-current switching applications. Index Terms--Bipolar-mode field

Kumar, M. Jagadesh

245

Electrothermal Effects in Bipolar Differential Pairs L. La Spina, V. d'Alessandro, F. Santagata, N. Rinaldi, and L. K. Nanver  

E-print Network

Electrothermal Effects in Bipolar Differential Pairs L. La Spina, V. d'Alessandro, F. Santagata, N -- The electrothermal behavior of bipolar differential pairs fabricated in silicon-on-glass technology is investigated the electrothermal feedback. Index Terms -- Analog circuits, Bipolar Junction Transistor (BJT), differential pair

Technische Universiteit Delft

246

Nonlinear system analysis in bipolar integrated circuits  

NASA Astrophysics Data System (ADS)

Since analog bipolar integrated circuits (IC's) have become important components in modern communication systems, the study of the Radio Frequency Interference (RFI) effects in bipolar IC amplifiers is an important subject for electromagnetic compatibility (EMC) engineering. The investigation has focused on using the nonlinear circuit analysis program (NCAP) to predict RF demodulation effects in broadband bipolar IC amplifiers. The audio frequency (AF) voltage at the IC amplifier output terminal caused by an amplitude modulated (AM) RF signal at the IC amplifier input terminal was calculated and compared to measured values. Two broadband IC amplifiers were investigated: (1) a cascode circuit using a CA3026 dual differential pair; (2) a unity gain voltage follower circuit using a micro A741 operational amplifier (op amp). Before using NCAP for RFI analysis, the model parameters for each bipolar junction transistor (BJT) in the integrated circuit were determined. Probe measurement techniques, manufacturer's data, and other researcher's data were used to obtain the required NCAP BJT model parameter values. An important contribution included in this effort is a complete set of NCAP BJT model parameters for most of the transistor types used in linear IC's.

Fang, T. F.; Whalen, J. J.

1980-01-01

247

New dynamic FET logic and serial memory circuits for VLSI GaAs technology  

NASA Technical Reports Server (NTRS)

The complexity of GaAs field effect transistor (FET) very large scale integration (VLSI) circuits is limited by the maximum power dissipation while the uniformity of the device parameters determines the functional yield. In this work, digital GaAs FET circuits are presented that eliminate the DC power dissipation and reduce the area to 50% of that of the conventional static circuits. Its larger tolerance to device parameter variations results in higher functional yield.

Eldin, A. G.

1991-01-01

248

Static induction transistors - HF to X band  

Microsoft Academic Search

The operation principles and the advantages of static induction transistors (SITs) are discussed with special attention given to silicon SITs. Some of the performance characteristics (such as voltage gain, transconductance, and capacitance) of recently fabricated silicon surface-gate SITs (SGSITs) and of a computer-simulated GaAs SIT are presented. It is shown that, while the SGSITSs exhibit excellent output power and efficiency

Robert J. Regan; Scott J. Butler; Craig A. Armiento; Frederick C. Rock

1987-01-01

249

Total Dose Effects on Bipolar Integrated Circuits at Low Temperature  

NASA Technical Reports Server (NTRS)

Total dose damage in bipolar integrated circuits is investigated at low temperature, along with the temperature dependence of the electrical parameters of internal transistors. Bandgap narrowing causes the gain of npn transistors to decrease far more at low temperature compared to pnp transistors, due to the large difference in emitter doping concentration. When irradiations are done at temperatures of -140 deg C, no damage occurs until devices are warmed to temperatures above -50 deg C. After warm-up, subsequent cooling shows that damage is then present at low temperature. This can be explained by the very strong temperature dependence of dispersive transport in the continuous-time-random-walk model for hole transport. For linear integrated circuits, low temperature operation is affected by the strong temperature dependence of npn transistors along with the higher sensitivity of lateral and substrate pnp transistors to radiation damage.

Johnston, A. H.; Swimm, R. T.; Thorbourn, D. O.

2012-01-01

250

High voltage bipolar mode SIT with low power loss  

Microsoft Academic Search

The characteristics of a novel 500-V, 200-A bipolar-mode SIT (static induction transistor) are reported. The sustaining voltage is the key aspect of the voltage capability under an inductive load switching; it can be improved without affecting the current gain or the switching speed. Reduction of the gate resistance is effective in raising the sustaining voltage. The current gain is improved

H. Takagi; H. Kawauchi; T. Yoshida; S. Miura; H. Ito; H. Tadano

1993-01-01

251

Comparison of the degradation effects of heavy ion, electron, and cobalt-60 irradiation in an advanced bipolar process  

NASA Technical Reports Server (NTRS)

Experimental measurements are reported of the degradation effects of high-energy particles (heavy Br ions and electrons) and Co-60 gamma-rays on the current gain of minimum-geometry bipolar transistors made from an advanced process. The data clearly illustrate the total-ionizing-dose vs particle-fluence behavior of this bipolar transistor produced by an advanced process. In particular, bulk damage from Co-60 gamma rays in bipolar transistors (base transport factor degradation) and surface damage in bipolar transistors from ionizing radiation (emitter-efficiency degradation) have been observed. The true equivalence between various types of radiation for this process technology has been determined on the basis of damage from the log K1 intercepts.

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

1988-01-01

252

Graphene transistors.  

PubMed

Graphene has changed from being the exclusive domain of condensed-matter physicists to being explored by those in the electron-device community. In particular, graphene-based transistors have developed rapidly and are now considered an option for post-silicon electronics. However, many details about the potential performance of graphene transistors in real applications remain unclear. Here I review the properties of graphene that are relevant to electron devices, discuss the trade-offs among these properties and examine their effects on the performance of graphene transistors in both logic and radiofrequency applications. I conclude that the excellent mobility of graphene may not, as is often assumed, be its most compelling feature from a device perspective. Rather, it may be the possibility of making devices with channels that are extremely thin that will allow graphene field-effect transistors to be scaled to shorter channel lengths and higher speeds without encountering the adverse short-channel effects that restrict the performance of existing devices. Outstanding challenges for graphene transistors include opening a sizeable and well-defined bandgap in graphene, making large-area graphene transistors that operate in the current-saturation regime and fabricating graphene nanoribbons with well-defined widths and clean edges. PMID:20512128

Schwierz, Frank

2010-07-01

253

Transistor Effect in Improperly Connected Transistors.  

ERIC Educational Resources Information Center

Discusses the differences between the standard representation and a realistic representation of a transistor. Presents an experiment that helps clarify the explanation of the transistor effect and shows why transistors should be connected properly. (JRH)

Luzader, Stephen; Sanchez-Velasco, Eduardo

1996-01-01

254

GaAs Optoelectronic Integrated-Circuit Neurons  

NASA Technical Reports Server (NTRS)

Monolithic GaAs optoelectronic integrated circuits developed for use as artificial neurons. Neural-network computer contains planar arrays of optoelectronic neurons, and variable synaptic connections between neurons effected by diffraction of light from volume hologram in photorefractive material. Basic principles of neural-network computers explained more fully in "Optoelectronic Integrated Circuits For Neural Networks" (NPO-17652). In present circuits, devices replaced by metal/semiconductor field effect transistors (MESFET's), which consume less power.

Lin, Steven H.; Kim, Jae H.; Psaltis, Demetri

1992-01-01

255

Superiority of p-type spin transistors  

NASA Astrophysics Data System (ADS)

The spintronic device that has probably stimulated the most research interest is the Datta-Das spin transistor. The mechanism behind it, called the Rashba effect, is that an applied voltage gives rise to a spin splitting. We demonstrate that the relevant spin splitting in k-space can be made more than three orders of magnitude larger for holes than for electrons at the same electric field. This is partly achieved by utilizing the frequently neglected lattice-mismatch between GaAs and AlGaAs. We design heterostructures where this efficient Rashba effect should show up. Compared to present transistors, we conclude that electron-based spin transistors will have problems in becoming competitive but hole-based ones are much more promising.

Gvozdic, D. M.; Ekenberg, U.

2006-09-01

256

Electrical traps in GaAs microwave F.E.T.s  

Microsoft Academic Search

Described is a rapid, sensitive technique for determining the activation energies for electron traps present in the channel of GaAs microwave field-effect transistors. The measurements can be made directly on the FETs. Taken together with systematic variation of growth procedures, the method can be applied toward identification and elimination of the traps.

M. G. Adlerstein

1976-01-01

257

A Heteroepitaxial Perovskite Metal-Base Transistor  

SciTech Connect

'More than Moore' captures a concept for overcoming limitations in silicon electronics by incorporating new functionalities in the constituent materials. Perovskite oxides are candidates because of their vast array of physical properties in a common structure. They also enable new electronic devices based on strongly-correlated electrons. The field effect transistor and its derivatives have been the principal oxide devices investigated thus far, but another option is available in a different geometry: if the current is perpendicular to the interface, the strong internal electric fields generated at back-to-back heterojunctions can be used for oxide electronics, analogous to bipolar transistors. Here we demonstrate a perovskite heteroepitaxial metal-base transistor operating at room temperature, enabled by interface dipole engineering. Analysis of many devices quantifies the evolution from hot-electron to permeable-base behaviour. This device provides a platform for incorporating the exotic ground states of perovskite oxides, as well as novel electronic phases at their interfaces.

Yajima, T.; Hikita, Y.; /Tokyo U.; Hwang, H.Y.; /Tokyo U. /JST, PRESTO /SLAC; ,

2011-08-11

258

Low and High Frequency Noise Properties of Heterojunction Transistors  

NASA Astrophysics Data System (ADS)

This thesis studies: (i) the noise properties of AlGaAs/GaAs Heterojunction Bipolar Transistors (HBT's) and novel High Electron Mobility Transistors (HEMT's) and (ii) the necessary measurement techniques. The baseband noise of AlGaAs/GaAs power HBT's and its upconversion to the operating frequency by non -linear device operation were studied. Comparison of direct and indirect measurement techniques for baseband noise demonstrated that direct measurements were the best to use. In all cases, the collector noise was greater than the base noise. Each contained different spectral components indicating that at least two intrinsic noise sources exist. The frequency and bias dependences of the spectra indicated that the origins of the noise were recombination based mechanisms, demonstrating that these devices are not at their technological limit. The role of baseband noise upconversion in the phase noise of HBT based dielectric resonator oscillators (DRO's) was studied for the first time and it was shown that in most cases the oscillator noise can be approximated by the HBT's baseband noise and the DRO's upconversion coefficient. The impact of base termination, collector current, and frequency on baseband noise, upconversion coefficient and phase noise are reported. The Y-factor and the noise power measurement approaches were compared to determine which is the best for determining HEMT microwave noise properties. Experiments demonstrated that the Y-factor approach has greater uncertainty than the noise power approach. Simulations showed that the Y-factor approach is sensitive to tuner magnitude errors, while, the noise power approach is sensitive to tuner phase errors. The microwave noise properties of double-doped strained InP HEMT's were analyzed and reported for the first time. The measured minimum noise figure, F _{min}, is as low as 0.3dB at 10GHz. The intrinsic drain noise current, overline{i _sp{dsn}{2}}, however, is >7dB larger than that of longer gate GaAs MESFET's. The excellent F_{min } is due to the reduced sqrt {overline{i_sp{dsn}{2 }}}/f_{T} (f_ {T} is the cutoff frequency) ratio. Stability studies of HEMT's indicated that all electrical parameters decreased rapidly with applied thermal stress. f_{T} decreased from 141GHz to 90GHz and f_{max} decreased from 164GHz to 120GHz. This was primarily due to degradation of the device gain. Measurements indicated that increased trapping below the channel is a possible cause of the degradation.

Tutt, Marcel Nicholas

1994-01-01

259

Low dark current GaAs metal-semiconductor-metal (MSM) photodiodes using WSi(x) contacts  

Microsoft Academic Search

The fabrication and characterization of metal-semiconductor-metal (MSM) photodiodes using the same undoped GaAs layer that is used as a buffer layer in the epitaxial structure for GaAs field effect transistors (FET's) is presented. To study the dark current mechanism, various metal electrodes used for Schottky contacts are examined. A drastic V-shape relationship between the dark current of the MSM photodiode

M. Ito; O. Wada

1986-01-01

260

Breakdown in millimeter-wave power InP HEMTs: a comparison with GaAs PHEMT's  

Microsoft Academic Search

In spite of their outstanding transport characteristics, InP high-electron mobility transistors (HEMTs) deliver lower output power than GaAs pseudomorphic HEMTs (PHEMTs) throughout most of the millimeter-wave regime. However, the superior power-added efficiency of InP HEMTs when compared with GaAs PHEMTs makes this technology attractive for many applications. The reason for the relatively inferior power output of InP HEMTs lies in

J. A. del Alamo; M. H. Somerville

1999-01-01

261

The determination and importance of internal capacitances of transistors in the frequency band of commercial FM broadcasting  

Microsoft Academic Search

Using a single-capacitor Colpitts oscillator a method has been proposed for determination of internal capacitances of bipolar junction transistors (BJTs) and junction field effect transistors (JFETs) in the frequency band of commercial frequency modulation (FM) broadcasting. Variation of these capacitances with the operating bias point and the operating frequency of the active device has been considered. Practical implementation of this

Reza Golparvar Roozbahani

2006-01-01

262

Gate-all-around carbon nanotube field-effect transistor  

NASA Astrophysics Data System (ADS)

The ultra-thin body of carbon nanotubes allows for aggressive channel length scaling while maintaining excellent gate control. In general, a gate-all-around (GAA) structure is expected to be the ideal geometry that maximizes electrostatic gate control in FETs. Combining the ultra-thin body of a carbon nanotube with a GAA device geometry is a natural choice for ultimate device design. In this talk, we demonstrate a gate-all-around single wall carbon nanotube field-effect transistor. This is the first successful experimental implementation of an off-chip gate and gate-dielectric assembly with subsequent deposition on a suitable substrate.

Chen, Zhihong; Farmer, Damon; Xu, Sheng; Gordon, Roy; Avouris, Phaedon; Appenzeller, Joerg

2008-03-01

263

Study of bipolar batteries  

NASA Astrophysics Data System (ADS)

The status of development of bipolar batteries with an aqueous electrolyte was determined. Included in the study were lead-acid, nickel-cadmium, nickel-zinc, nickel-iron, and nickel-hydrogen batteries. The technical and patent literature is reviewed and a bibliography covering the past 15 years is presented. Literature data are supplemented by a survey of organizations. The principal interest was in bipolar lead-acid batteries and more recently in bipolar nickel-hydrogen batteries for space applications.

Clifford, J. E.

1984-06-01

264

Modeling of enclosed-gate layout transistors as ESD protection device based on conformal mapping method  

NASA Astrophysics Data System (ADS)

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.

Jia, Zhang; Haigang, Yang; Jiabin, Sun; Le, Yu; Yuanfeng, Wei

2014-08-01

265

Sub20 ps silicon bipolar technology using selective epitaxial growth  

Microsoft Academic Search

A sub-20 ps silicon bipolar technology has been developed using selective epitaxial growth (SEG) for the active base and collector regions. This transistor concept allows the simultaneous reduction of base width and base\\/collector capacitance while maintaining low extrinsic base resistance. At a current of 0.8 mA a record CML gate delay time of 18 ps is achieved with devices showing

T. F. Meister; R. Stengl; H. W. Meul; R. Weyl; P. Packan; A. Felder; H. Klose; R. Schreiter; J. Popp; H. M. Rein; L. Treitinger

1992-01-01

266

Forward-bias tunneling: A limitation to bipolar device scaling  

Microsoft Academic Search

Forward-bias tunneling is observed in heavily doped p-n junctions of bipolar transistors. A simple phenomenological model suitable to incorporation in device codes is developed. The model identifies as key parameters the space-charge-region (SCR) thickness at zero bias and the reduced doping level at its edges which can both be obtained from CV characteristics. This tunneling mechanism may limit the maximum

JESUS A. DEL ALAMO; RICHARD M. SWANSON

1986-01-01

267

Bipolar radiofrequency for adenoidectomy  

Microsoft Academic Search

tolaryngologists have utilized bipolar radiofrequency for tonsillectomy for nearly 5 years, although many switch to a curette or suction cautery to remove the ade- noids. Since adopting Coblation bipolar radiofrequency (ArthroCare Corporation, Sunnyvale, CA) for tonsil re- moval, the author has seen patient benefits, including min- imal blood loss and less thermal damage, leading to a more thorough dissection and

J. Mark Palmer

2006-01-01

268

Bipolar coagulation - capable microforceps  

Microsoft Academic Search

Microforceps that can be used with the hyper utility mechatronic assistant system (HUMAN) for bipolar coagulation in minimally invasive neurosurgery were developed. A method of using two sets of those forceps for bipolar coagulation was developed, in which electrical current is passed through the drive wires to the forceps tips to form an electrical circuit. A prototype mechanism that employs

TOSHIKAZU KAWAI; KAZUTOSHI KAN; KAZUHIRO HONGO; KOUJI NISHIZAWA; FUJIO TAJIMA; MASAKATSU G. FUJIE; TAKEYOSHI DOHI; KINTOMO TAKAKURA

2005-01-01

269

A bipolar kinesin  

PubMed Central

Chromosome segregation during mitosis depends on the action of the mitotic spindle, a self-organizing, bipolar protein machine which uses microtubules (MTs) and their associated motors1,2. Members of the BimC subfamily of kinesin-related MT–motor proteins are believed to be essential for the formation and functioning of a normal bipolar spindle3–14. Here we report that KRP130, a homotetrameric BimC-related kinesin purified from Drosophila melanogaster embryos13, has an unusual ultrastructure. It consists of four kinesin-related polypeptides assembled into a bipolar aggregate with motor domains at opposite ends, analogous to a miniature myosin filament15. Such a bipolar ‘minifilament’ could crosslink spindle MTs and slide them relative to one another. We do not know of any other MT motors that have a bipolar structure. PMID:8538794

Kashina, A. S.; Baskin, R. J.; Cole, D. G.; Wedaman, K. P.; Saxton, W. M.; Scholey, J. M.

2011-01-01

270

Actigraphy in Remitted Bipolar Patients SLEEP IN REMITTED BIPOLAR DISORDER  

E-print Network

Actigraphy in Remitted Bipolar Patients 1 SLEEP IN REMITTED BIPOLAR DISORDER: A NATURALISTIC CASE;158:1-7" DOI : 10.1016/j.jad.2014.01.012 #12;Actigraphy in Remitted Bipolar Patients 2 Abstract (244) Introduction: Findings from actigraphic studies that sleep and circadian rhythms are disrupted in bipolar

Boyer, Edmond

271

Relaxation of Si-SiO{sub 2} interfacial stress in bipolar screen oxides due to ionizing radiation  

SciTech Connect

Current gain degradation due to ionizing radiation in complementary single-crystalline emitter bipolar transistors was found to grow progressively worse upon subjecting the transistors to repeated cycles of radiation exposure and high-temperature anneal. The increase in radiation sensitivity is independent of the emitter polarity or geometry and is most dramatic between the first and second radiation and anneal cycles. In parallel with the current gain measurements, samples from a monitor wafer simulating the screen oxide region above the extrinsic base in the npn transistors were measured for mechanical stress while undergoing similar cycles of irradiation and anneal. The oxide on the monitor wafer consisted of a 45 nm thermal layer and a 640 nm deposited layer. The results indicate that ionizing radiation helped relieve compressive stress at the Si surface. The magnitude of the stress change due to radiation is smaller than the stress induced by the emitter contact metallization followed by a post-metallization anneal. Correlation of radiation sensitivity in the bipolar transistors and mechanical stress in the monitor wafer suggests that mechanical stress may be influential in determining the radiation hardness of bipolar transistors and lends validation to previously reported observations that Si-SiO{sub 2} interfaces are increasingly more susceptible to radiation damage with decreasing Si compressive stress. Possible mechanisms for the observed changes in stress and their effect on the radiation sensitivity of the bipolar transistors are discussed.

Witczak, S.C.; Galloway, K.F.; Schrimpf, R.D. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Electrical and Computer Engineering] [Univ. of Arizona, Tucson, AZ (United States). Dept. of Electrical and Computer Engineering; Suehle, J.S. [National Inst. of Standards and Technology, Gaithersburg, MD (United States). Semiconductor Electronics Div.] [National Inst. of Standards and Technology, Gaithersburg, MD (United States). Semiconductor Electronics Div.

1995-12-01

272

Gigahertz operation in flexible transistors on plastic substrates  

Microsoft Academic Search

The combined use of GaAs wires with Ohmic contacts formed from bulk wafers, soft lithographic transfer printing techniques, and optimized device designs enables mechanically flexible transistors to be formed on low-cost plastic substrates, with individual device speeds in the gigahertz range and with high degrees of mechanical bendability. These high-speed devices incorporate materials in simple layouts that can be fabricated

Yugang Sun; Etienne Menard; John A. Rogers; Hoon-Sik Kim; Seiyon Kim; Guang Chen; Ilesanmi Adesida; Ross Dettmer; Rebecca Cortez; Alan Tewksbury

2006-01-01

273

High speed static induction transistor for pulsed power applications  

Microsoft Academic Search

The proposed design and fabrication of a recessed-gate GaAs static induction transistor (SIT) are reported. The SIT is a vertical channel, field-effect switching device which exhibits gate-induced turn-on and turn-off and is well-suited for pulsed power applications. Modeling of the device has been performed to correlate the experimentally observed characteristics with calculated values upon fabrication. The base (channel) layer is

P. Hadizad; J. H. Hur; S. Hummel; M. A. Gundersen; H. R. Fetterman

1990-01-01

274

Bipolar Disorder in Children  

PubMed Central

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

2014-01-01

275

Bipolar fuel cell  

DOEpatents

The present invention discloses an improved fuel cell utilizing an ion transporting membrane having a catalytic anode and a catalytic cathode bonded to opposite sides of the membrane, a wet-proofed carbon sheet in contact with the cathode surface opposite that bonded to the membrane and a bipolar separator positioned in electrical contact with the carbon sheet and the anode of the adjacent fuel cell. Said bipolar separator and carbon sheet forming an oxidant flowpath, wherein the improvement comprises an electrically conductive screen between and in contact with the wet-proofed carbon sheet and the bipolar separator improving the product water removal system of the fuel cell.

McElroy, James F. (Suffield, CT)

1989-01-01

276

Bipolar disorder in women.  

PubMed

This article summarizes research pertinent to the clinical care of women with bipolar disorder. With bipolar disorder, female gender correlates with more depressive symptoms and different comorbidities. There is a high risk of symptom recurrence postpartum and possibly during perimenopause. Women with bipolar disorder have increased risk of sexually transmitted diseases, unplanned pregnancies, excessive weight gain, metabolic syndrome, and cardiovascular disease. Mood stabilizing medications, specific psychotherapies, and lifestyle changes can stabilize mood and improve functioning. Pharmacologic considerations include understanding interactions between mood stabilizing medications and contraceptive agents and risks and benefits of mood stabilizing medication during pregnancy and lactation. PMID:25315819

Miller, Laura J; Ghadiali, Nafisa Y; Larusso, Elizabeth M; Wahlen, Kelly J; Avni-Barron, Orit; Mittal, Leena; Greene, Judy A

2015-04-01

277

Modeling substrate effects in the design of high-speed Si-bipolar ICs  

Microsoft Academic Search

In the design of high-speed IC's, the influence of the substrate on circuit performance must be considered carefully. Therefore, in this paper the contribution of the p- substrate and channel stopper to the equivalent circuits of Si-bipolar transistors and bond pads are theoretically and experimentally investigated up to very high frequencies. Improved equivalent substrate circuits, well suited for standard circuit

Martin Pfost; Hans-Martin Rein; Thomas Holzwarth

1996-01-01

278

Influence of bulk inversion asymmetry on the Datta-Das transistor  

NASA Astrophysics Data System (ADS)

The influence of bulk inversion asymmetry on spin field effect transistor is studied. It is shown that the period of Datta-Das oscillations changes with subband index. The conductance is found to depend significantly on the crystallographic orientation of the device channel. The optimal channel directions in GaAs- and InAs-based devices are determined.

?usakowski, A.; Wróbel, J.; Dietl, T.

2004-03-01

279

The HP 85192B EEFet3 GaAs FET Nonlinear Model Used in the High Efficiency Microwave Power Amplifier (HEMPA)  

NASA Technical Reports Server (NTRS)

Most nonlinear circuit analysis programs that exist today were designed primarily for transient analysis. By incorporating more accurate models in simulation programs, accurate predictions of GaAs field effect transistors (FET) behavior can be accomplished. However, should the designer need to simulate GaAs FETs that operate at high DC-to-RF conversion efficiencies, a more sophisticated model is needed. A relevant and appropriate method is called harmonic-balance, as described by Quere et al.

Sims, William Herbert, III; Bell, Joseph L. (Technical Monitor)

2001-01-01

280

Negative-differential-resistance-switching Si-transistor operated by power pulse and identity of Zener breakdown  

NASA Astrophysics Data System (ADS)

The identity of Zener breakdown is interpreted as metal-insulator transition (MIT). For a negative-differential-resistance (NDR) Si-transistor as a sort of MIT transistor, a structure of "reverse-pn-junction (insulator role for tunneling) and MIT" is proposed. Its characteristics are investigated through the reverse active mode of a donor-acceptor-donor bipolar transistor, similar to the NDR-transistor structure. As evidence of the MIT at outlet layer, the Ohmic behavior in I-V measurements and the NDR in a 100 KHz power pulse are observed. It switches a much higher current than a bipolar transistor when the MIT occurs and can be used as a power device.

Kim, Hyun-Tak

2013-10-01

281

A silicon nanocrystal tunnel field effect transistor  

SciTech Connect

In this work, we demonstrate a silicon nanocrystal Field Effect Transistor (ncFET). Its operation is similar to that of a Tunnelling Field Effect Transistor (TFET) with two barriers in series. The tunnelling barriers are fabricated in very thin silicon dioxide and the channel in intrinsic polycrystalline silicon. The absence of doping eliminates the problem of achieving sharp doping profiles at the junctions, which has proven a challenge for large-scale integration and, in principle, allows scaling down the atomic level. The demonstrated ncFET features a 10{sup 4} on/off current ratio at room temperature, a low 30?pA/?m leakage current at a 0.5?V bias, an on-state current on a par with typical all-Si TFETs and bipolar operation with high symmetry. Quantum dot transport spectroscopy is used to assess the band structure and energy levels of the silicon island.

Harvey-Collard, Patrick, E-mail: P.Collard@USherbrooke.ca [Département de Physique, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Quebec J1K 2R1 (Canada); Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, 3000 Boulevard de l'Université, Sherbrooke, Quebec J1K 0A5 (Canada); Laboratoire Nanotechnologies Nanosystèmes (LN2)–CNRS UMI-3463, Université de Sherbrooke, 3000 Boulevard de l'Université, Sherbrooke, Quebec J1K 0A5 (Canada); Drouin, Dominique [Institut Interdisciplinaire d'Innovation Technologique (3IT), Université de Sherbrooke, 3000 Boulevard de l'Université, Sherbrooke, Quebec J1K 0A5 (Canada); Laboratoire Nanotechnologies Nanosystèmes (LN2)–CNRS UMI-3463, Université de Sherbrooke, 3000 Boulevard de l'Université, Sherbrooke, Quebec J1K 0A5 (Canada); Pioro-Ladrière, Michel [Département de Physique, Université de Sherbrooke, 2500 Boulevard de l'Université, Sherbrooke, Quebec J1K 2R1 (Canada); CIFAR Program in Quantum Information Science, Canadian Institute for Advanced Research (CIFAR), Toronto, Ontario M5G 1Z8 (Canada)

2014-05-12

282

A novel CMOS-compatible high-voltage transistor structure  

NASA Astrophysics Data System (ADS)

A novel high-voltage transistor structure, the insulated base transistor (IBT), based on a merged MOS-bipolar concept, is described. This device, which can be implemented using a standard CMOS process, is capable of handling high current densities without latching. The IBT exhibits a fivefold increase in current density compared to the lateral DMOS. A simple technique by which the switching speeds of the IBT can be improved by almost an order of magnitude without significantly compromising its current carrying capability is also presented.

Parpia, Zahir; Salama, C. Andre T.; Mena, Jose G.

1986-12-01

283

Gated Conductance of Thin Indium Tin Oxide - The Simplest Transistor  

E-print Network

Transistors are the fundamental building block of modern electronic devices. So far, all transistors are based on various types of semiconductor junctions. The most common bipolar-junction transistors and metal-oxide-semiconductor field-effect transistors contain p-n junctions to control the current, depending on applied biases across the junctions. Thin-film transistors need metal-semiconductor junctions for injecting and extracting electrons from their channels. Here, by coating a heavily-doped thin indium-tin-oxide (ITO) film through a shadow mask onto a biopolymer chitosan/ITO/glass substrate, we can have a high-performance junctionless transparent organic-inorganic hybrid thin film transistor. This could be the simplest transistor in the world, to our knowledge, not only in its structure, but also its fabrication process. In addition, the device performance is found to be greatly enhanced using a reinforced chitosan/SiO2 hybrid bilayer dielectric stack. Our results clearly show that this architecture can...

Jiang, Jie; Sun, Jia; Dou, Wei; Zhang, Qing

2012-01-01

284

Bipolar Disorder in Adults  

MedlinePLUS

... or irritable Changing eating, sleeping, or other habits Thinking of death or suicide, or attempting suicide. Bipolar ... look for are depression that gets worse, suicidal thinking or behavior, or any unusual changes in behavior ...

285

Treatment of bipolar depression.  

PubMed

Depression is usually the predominant phase in bipolar disorder, causes the most psychosocial disability, and carries significant risk of suicide. The management of bipolar depression is relatively under-studied and poses significant challenges for clinicians. There is substantial dissent regarding optimal pharmacotherapy for bipolar depression, particularly around the role of antidepressants. Individual and combination pharmacotherapy should be integrated into a personalised psychosocial and lifestyle package of interventions that considers the person's clinical profile and preferences. The relative lack of evidence relating to optimal strategies, especially when bipolar depression occurs with common comorbidities, poses challenges and requires further research. A flexible approach and evidence-based combinations of treatments can provide effective strategies for improving quality of life and reducing morbidity and mortality. PMID:25370283

Berk, Michael; Berk, Lesley; Davey, Christopher G; Moylan, Steven; Giorlando, Francesco; Singh, Ajeet B; Kalra, Harish; Dodd, Seetal; Malhi, Gin S

2013-09-16

286

Bipolar thermoelectric devices  

E-print Network

The work presented here is a theoretical and experimental study of heat production and transport in bipolar electrical devices, with detailed treatment of thermoelectric effects. Both homojunction and heterojunction devices ...

Pipe, Kevin P. (Kevin Patrick), 1976-

2004-01-01

287

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

PubMed

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. PMID:25686555

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

2015-02-25

288

Experimental determination of single-event upset (SEU) as a function of collected charge in bipolar integrated circuits  

Microsoft Academic Search

Single-Event Upset (SEU) in bipolar integrated circuits (ICs) is caused by charge collection from ion tracks in various regions of a bipolar transistor. This paper presents experimental data which have been obtained wherein the range-energy characteristics of heavy ions (Br) have been utilized to determine the cross section for soft-error generation as a function of charge collected from single-particle tracks

J. A. Zoutendyk; C. J. Malone; L. S. Smith

1984-01-01

289

Method and apparatus for increasing resistance of bipolar buried layer integrated circuit devices to single-event upsets  

NASA Technical Reports Server (NTRS)

Bipolar transistors fabricated in separate buried layers of an integrated circuit chip are electrically isolated with a built-in potential barrier established by doping the buried layer with a polarity opposite doping in the chip substrate. To increase the resistance of the bipolar transistors to single-event upsets due to ionized particle radiation, the substrate is biased relative to the buried layer with an external bias voltage selected to offset the built-in potential just enough (typically between about +0.1 to +0.2 volt) to prevent an accumulation of charge in the buried-layer-substrate junction.

Zoutendyk, John A. (inventor)

1991-01-01

290

Bipolar Disorder in Children and Teens  

MedlinePLUS

... this brochure to find out more. What is bipolar disorder? Bipolar disorder is a serious brain illness. ... their symptoms and lead successful lives. Who develops bipolar disorder? Anyone can develop bipolar disorder, including children ...

291

Surface manipulation of GaAs and its application in producing new structural elements for communication engineering  

NASA Astrophysics Data System (ADS)

Methods of surface passivation of GaAs including electrolytic and gas-plasma-oxidation of semiconductors as well as the plotting of external isolators such as Si(3)N(4) through gas-chemical reactions are presented. Anodic oxidation is discussed that is employed in determining the load carrier density in GaAs by measuring the proportional breakdown voltage of the oxide prior to the oxidation process. Attention is given to MOS delay lines on GaAs produced through anodic oxidation and also to various MOS structures and transistors (MOSFET and MESFETS). A table is presented that contrasts data regarding GaAs and InP MOSFET in Japanese, American, English and German laboratories.

Pavlidis, D.; Hartnagel, H. L.

1980-03-01

292

Design considerations for very-high-speed Si-bipolar IC's operating up to 50 Gb\\/s  

Microsoft Academic Search

In this paper, design aspects of high-speed digital and analog IC's are discussed which allow the designer to exhaust the high-speed potential of advanced Si-bipolar technologies. Starting from the most promising circuit concepts and an adequate resistance level, the dimensions of the individual transistors in the IC's must be optimized very carefully using advanced transistor models. It is shown how

H.-M. Rein; M. Moller

1996-01-01

293

Wideband DMOS amplifier competes with bipolars  

NASA Astrophysics Data System (ADS)

A wideband (40-350 MHz) hybrid DMOS or double-diffused metal oxide semiconductor amplifier is described that has been designed and built to demonstrate the feasibility of the device in cable communications systems (currently dominated by bipolar hybrid IC). The advantages of the DMOS transistor include high input impedance, high current gain and power gain, and no thermal runaway problems. Furthermore, in a DMOS, a very short channel length (a micron or less) is possible without submicrometer lithography, and a high breakdown voltage can be obtained and tailored independently of the channel length by incorporating a lightly doped drift region between the active region and the drain contact. Three circuit configurations were investigated: multiple feedback, cascode, and cascade. Thick-film technology was used to implement the circuit. Amplifier characteristics are tabulated.

Salama, C. A. T.; Sin, J. K. O.

1986-06-01

294

Temperature dependence of electronic behaviors in quantum dimension junctionless thin-film transistor  

NASA Astrophysics Data System (ADS)

The high temperature dependence of junctionless (JL) gate-all-around (GAA) poly-Si thin-film transistors (TFTs) with 2-nm-thick nanosheet channel is compared with that of JL planar TFTs. The variation of SS with temperature for JL GAA TFTs is close to the theoretical value (0.2 mV/dec/K), owing to the oxidation process to form a 2-nm-thick channel. The bandgap of 1.35 eV in JL GAA TFTs by fitting experimental data exhibits the quantum confinement effect, indicating greater suppression of Ioff than that in JL planar TFTs. The measured [InlineEquation not available: see fulltext.] of -1.34 mV/°C in JL GAA nanosheet TFTs has smaller temperature dependence than that of -5.01 mV/°C in JL planar TFTs.

Cheng, Ya-Chi; Chen, Hung-Bin; Han, Ming-Hung; Lu, Nan-Heng; Su, Jun-Ji; Shao, Chi-Shen; Wu, Yung-Chun

2014-08-01

295

Temperature dependence of electronic behaviors in quantum dimension junctionless thin-film transistor.  

PubMed

The high temperature dependence of junctionless (JL) gate-all-around (GAA) poly-Si thin-film transistors (TFTs) with 2-nm-thick nanosheet channel is compared with that of JL planar TFTs. The variation of SS with temperature for JL GAA TFTs is close to the theoretical value (0.2 mV/dec/K), owing to the oxidation process to form a 2-nm-thick channel. The bandgap of 1.35 eV in JL GAA TFTs by fitting experimental data exhibits the quantum confinement effect, indicating greater suppression of Ioff than that in JL planar TFTs. The measured [Formula: see text] of -1.34 mV/°C in JL GAA nanosheet TFTs has smaller temperature dependence than that of -5.01 mV/°C in JL planar TFTs. PMID:25147491

Cheng, Ya-Chi; Chen, Hung-Bin; Han, Ming-Hung; Lu, Nan-Heng; Su, Jun-Ji; Shao, Chi-Shen; Wu, Yung-Chun

2014-01-01

296

Temperature dependence of electronic behaviors in quantum dimension junctionless thin-film transistor  

PubMed Central

The high temperature dependence of junctionless (JL) gate-all-around (GAA) poly-Si thin-film transistors (TFTs) with 2-nm-thick nanosheet channel is compared with that of JL planar TFTs. The variation of SS with temperature for JL GAA TFTs is close to the theoretical value (0.2 mV/dec/K), owing to the oxidation process to form a 2-nm-thick channel. The bandgap of 1.35 eV in JL GAA TFTs by fitting experimental data exhibits the quantum confinement effect, indicating greater suppression of Ioff than that in JL planar TFTs. The measured ?Vth?T of ?1.34 mV/°C in JL GAA nanosheet TFTs has smaller temperature dependence than that of ?5.01 mV/°C in JL planar TFTs. PMID:25147491

2014-01-01

297

[Antipsychotics in bipolar disorders].  

PubMed

This article is a review of the various treatments that are currently available, in particular in France, for the treatment of bipolar disorders. This article specifically addresses the use of novel antipsychotic agents as alternative therapy to a lithium therapy and/or the use of conventional antipsychotics. The prevalence of bipolar disorder over a lifetime is around 1% of the general population. Bipolar disorder consists of alternating depressive and manic episodes. It mainly affects younger subjects, and is often associated with alcohol and drug addictions. There are two main subtypes of bipolar disorder. According to the DSM IV-R, type 1 of bipolar disorder is characterised when at least one manic episode (or a mixed episode) has been diagnosed. Type 2 of bipolar disorder is related to patients enduring recurrent depressive episodes but no manic episode. Type 2 affects women more frequently as opposed to type 1 affecting individuals of both sexes. Manic-depressive disorder (or cyclo-thymic disorder) appears in relation to patients who has never suffered manic episode, mixed episode or severe depressive episode but have undergone numerous periods with some symptoms of depression and hypomanic symptoms over a two-year period during which any asymptomatic periods last no longer than two months. The average age of the person going through a first episode (often a depressive one) is 20 years-old. Untreated bipolar patients may endure more than ten manic or depressive episodes. Finally, in relation to 10 to 20% of patients, the bipolar disorder will turn into a fast cycle form, either spontaneously or as a result of certain medical treatments. Psychiatrists are now able to initiate various treating strategies which are most likely to be effective as a result of the identification of clinical subtypes of the bipolar disorder. Lithium therapy has been effectively and acutely used for patients with pure or elated mania and its prophylaxis. However, lithium medication may worsen depressive symptoms when used for a long term maintenance therapy. Additionally, mixed mania, rapid cycling type patients and bipolar disorder associated with substance abuse do not respond well to lithium therapy. In addition to the lithium therapy or in place of a lithium therapy, one can report the frequent use of antipsychotic agents in respect of patients with bipolar disorder during both the acute and maintenance phases of treatment. Antipsychotic agents have been used for almost forty years and may be used in combination with a lithium therapy. Conventional antipsychotics are effective but they may induce late dyskinesia, weight gain, sedation, sexual dysfunction and depression. These adverse side effects often lead to non compliance in particular in circumstances where antipsychotic agents are combined with a lithium therapy. A number of alternative somatic treatment approaches have been reported for patients who do not respond well or who are intolerant to lithium therapy. As such, valproate has received regulatory approval for the acute treatment of mania and carbamazepine has been indicated for this condition in a number of countries. Divalproex (Depakote) has recently obtained the authorization to market in France and may be prescribed for manic states or hypomanic states that do not tolerate lithium therapy or for which lithium therapy is contraindicated. A number of other anticonvulsants (lamotrigine, gabapentin and topiramate) are currently being tested. Because of the side effects of the conventional antipsychotic agents, atypical antipsychotic agents are currently on trial and appear to be of interest in the treatment of bipolar disorders. Currently, a number of prospective studies are available with clozapine, risperidone and olanzapine in the treatment of bipolar disorder. Most are short-term studies. Recent randomised, double-blind, placebo-controlled studies have shown clozapine, risperidone and olanzapine to be effective with antimanic and antidepressive effects, both as monotherapy and as add-on maintenance therapy with lithium

Vacheron-Trystram, M-N; Braitman, A; Cheref, S; Auffray, L

2004-01-01

298

Transistors: The Field Effect  

NSDL National Science Digital Library

Transistors are the building blocks of modern electronic devices. Your cell phones, iPods, and computers all depend on them to operate. Thanks to today's microfabrication technology, transistors can be made very tiny and be massively produced. You are probably using billions of them while working with this activity now--as of 2006, a dual-core Intel microprocessor contains 1.7 billion transistors. The field effect transistor is the most common type of transistor. So we will focus on it in this activity.

The Concord Consortium

2011-12-11

299

Lightweight bipolar storage battery  

NASA Technical Reports Server (NTRS)

An apparatus [10] is disclosed for a lightweight bipolar battery of the end-plate cell stack design. Current flow through a bipolar cell stack [12] is collected by a pair of copper end-plates [16a,16b] and transferred edgewise out of the battery by a pair of lightweight, low resistance copper terminals [28a,28b]. The copper terminals parallel the surface of a corresponding copper end-plate [16a,16b] to maximize battery throughput. The bipolar cell stack [12], copper end-plates [16a,16b] and copper terminals [28a,28b] are rigidly sandwiched between a pair of nonconductive rigid end-plates [20] having a lightweight fiber honeycomb core which eliminates distortion of individual plates within the bipolar cell stack due to internal pressures. Insulating foam [30] is injected into the fiber honeycomb core to reduce heat transfer into and out of the bipolar cell stack and to maintain uniform cell performance. A sealed battery enclosure [ 22] exposes a pair of terminal ends [26a,26b] for connection with an external circuit.

Rowlette, John J. (Inventor)

1992-01-01

300

Depression and Bipolar Support Alliance  

MedlinePLUS

... events Visit the podcast archive Mood Disorders Depression Bipolar Disorder Anxiety Screening Center Co-occurring Illnesses/Disorders ... for Your Patients Information about Depression Information about Bipolar Disorder Wellness Tools DBSA Support Groups Active Research ...

301

Bipolar battery construction  

NASA Technical Reports Server (NTRS)

A lightweight, bipolar battery construction for lead acid batteries in which a plurality of thin, rigid, biplates each comprise a graphite fiber thermoplastic composition in conductive relation to lead stripes plated on opposite flat surfaces of the plates, and wherein a plurality of nonconductive thermoplastic separator plates support resilient yieldable porous glass mats in which active material is carried, the biplates and separator plates with active material being contained and maintained in stacked assembly by axial compression of the stacked assembly. A method of assembling such a bipolar battery construction.

Rippel, Wally E. (Inventor); Edwards, Dean B. (Inventor)

1981-01-01

302

Radiation effect on silicon transistors in mixed neutrons-gamma environment  

NASA Astrophysics Data System (ADS)

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.

Assaf, J.; Shweikani, R.; Ghazi, N.

2014-10-01

303

A dc model for power switching transistors suitable for computer-aided design and analysis  

NASA Technical Reports Server (NTRS)

A model for bipolar junction power switching transistors whose parameters can be readily obtained by the circuit design engineer, and which can be conveniently incorporated into standard computer-based circuit analysis programs is presented. This formulation results from measurements which may be made with standard laboratory equipment. Measurement procedures, as well as a comparison between actual and computed results, are presented.

Wilson, P. M.; George, R. T., Jr.; Owen, H. A.; Wilson, T. G.

1979-01-01

304

Design, Simulation and Modeling of Insulated Gate Bipolar Transistor  

E-print Network

of IGBT circuits based on device simulation and combinatorial optimization. Our method leads to the optimal IGBT layout consisting of hexagons, which is 6 % more efficient in terms of performance (current per unit area) over that of squares, and up to 80...

Gupta, Kaustubh

2013-07-09

305

Soft switch-avalanche IGBT convertor. [Insulated Gate Bipolar Transistor  

NASA Technical Reports Server (NTRS)

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.

Chen, K.; Stuart, T. A.

1990-01-01

306

SiC Power Bipolar Transistors and Thyristors  

Microsoft Academic Search

\\u000a Silicon has long been the dominant semiconductor of choice for high-voltage power electronics applications [1, 2]. However, recently, wide bandgap semiconductors, particularly SiC and GaN, have attracted much attention because they are\\u000a projected to have much better performance than silicon [3]–[8] and the epi\\/substrate technology has matured to make device commercialization possible. SiC offers a lower intrinsic carrier\\u000a concentration, a

T. P. Chow; N. Ramungul; J. Fedison; Y. Tang

307

Theory of semiconductor magnetic bipolar transistors M. E. Flattea)  

E-print Network

.1063/1.1586996 One motivation for semiconductor spin electronics has been the seminal suggestion of Datta and Das to generate almost 100% spin-polarized current injection into nonmagnetic semiconductors. Optical control of ferromagnetism and spin splitting in the base can lead to either long-lived or ultrafast switching behavior

Flatte, Michael E.

308

Nitrided Metallic Bipolar Plates  

SciTech Connect

The objectives are: (1) Develop and optimize stainless steel alloys amenable to formation of a protective Cr-nitride surface by gas nitridation, at a sufficiently low cost to meet DOE targets and with sufficient ductility to permit manufacture by stamping. (2) Demonstrate capability of nitridation to yield high-quality stainless steel bipolar plates from thin stamped alloy foils (no significant stamped foil warping or embrittlement). (3) Demonstrate single-cell fuel cell performance of stamped and nitrided alloy foils equivalent to that of machined graphite plates of the same flow-field design ({approx}750-1,000 h, cyclic conditions, to include quantification of metal ion contamination of the membrane electrode assembly [MEA] and contact resistance increase attributable to the bipolar plates). (4) Demonstrate potential for adoption in automotive fuel cell stacks. Thin stamped metallic bipolar plates offer the potential for (1) significantly lower cost than currently-used machined graphite bipolar plates, (2) reduced weight/volume, and (3) better performance and amenability to high volume manufacture than developmental polymer/carbon fiber and graphite composite bipolar plates. However, most metals exhibit inadequate corrosion resistance in proton exchange membrane fuel cell (PEMFC) environments. This behavior leads to high electrical resistance due to the formation of surface oxides and/or contamination of the MEA by metallic ions, both of which can significantly degrade fuel cell performance. Metal nitrides offer electrical conductivities up to an order of magnitude greater than that of graphite and are highly corrosion resistant. Unfortunately, most conventional coating methods (for metal nitrides) are too expensive for PEMFC stack commercialization or tend to leave pinhole defects, which result in accelerated local corrosion and unacceptable performance.

Brady, Michael P [ORNL; Tortorelli, Peter F [ORNL; Pihl, Josh A [ORNL; Toops, Todd J [ORNL; More, Karren Leslie [ORNL; Meyer III, Harry M [ORNL; Vitek, John Michael [ORNL; Wang, Heli [National Renewable Energy Laboratory (NREL); Turner, John [National Renewable Energy Laboratory (NREL); Wilson, Mahlon [Los Alamos National Laboratory (LANL); Garzon, Fernando [Los Alamos National Laboratory (LANL); Rockward, Tommy [Los Alamos National Laboratory (LANL); Connors, Dan [GenCell Corp; Rakowski, Jim [Allegheny Ludlum; Gervasio, Don [Arizona State University

2008-01-01

309

Rectifier characteristics based on bipolar-mode SIT operation  

SciTech Connect

A novel rectifier concept based on bipolar-mode static induction transistor (BSIT) operation is proposed. A numerical simulation has revealed that the turn-on mechanism of this rectifier, owing to a combination of static induction effects and minority carrier injection, can make its forward-voltage drop and reverse recovery time smaller than those of the conventional p-i-n rectifier. As an example of the design methods, the simulation has clarified the effects of decreasing the doping concentration in the chemical between p[sup +] regions on improvement in the tradeoff between a forward voltage drop and leakage current.

Yano, Koji; Kasuga, Masanobu; Shimizu, Azuma (Yamanashi Univ., Kofu (Japan). Dept. of Electrical Engineering and Computer Science); Mitsui, Masahito; Moroshima, Heiji; Morita, Junichi (Hitachi Ltd., Yamanashi (Japan). Semiconductor and Integrated Circuits Division)

1994-09-01

310

Transistor as a Rectifier  

E-print Network

Transistor is a three terminal semiconductor device normally used as an amplifier or as a switch. Here the alternating current (a.c) rectifying property of the transistor is considered. The ordinary silicon diode exhibits a voltage drop of ~0.6V across its terminals. In this article it is shown that the transistor can be used to build a diode or rectify low current a.c (~mA) with a voltage drop of ~0.03V. This voltage is ~20 times smaller than the silicon diode. This article gives the half-wave and full-wave transistor rectifier configurations along with some applications to justify their usefulness.

Baddi, Raju

2012-01-01

311

Transistor as a Rectifier  

E-print Network

Transistor is a three terminal semiconductor device normally used as an amplifier or as a switch. Here the alternating current (a.c) rectifying property of the transistor is considered. The ordinary silicon diode exhibits a voltage drop of ~0.6V across its terminals. In this article it is shown that the transistor can be used to build a diode or rectify low current a.c (~mA) with a voltage drop of ~0.03V. This voltage is ~20 times smaller than the silicon diode. This article gives the half-wave and full-wave transistor rectifier configurations along with some applications to justify their usefulness.

Raju Baddi

2013-04-20

312

The Transistor Museum  

NSDL National Science Digital Library

The Transistor Museum is a fascinating site "dedicated to preserving the history of the greatest invention of the 20th century." The museum's front page mentions some remarkable facts and quotes that demonstrate the importance of the transistor in modern life. Visitors can read transcripts of lectures, oral histories, and short biographies of notable individuals who played a role in the development of transistor applications. An impressive photo gallery showcases some of the most prominent historical transistors, while providing information about their usage, type, date of introduction, and other interesting notes.

2002-01-01

313

Modeling Low-Dose-Rate Effects in Irradiated Bipolar-Base Oxides  

SciTech Connect

A physical model is developed to quantify the contribution of oxide-trapped charge to enhanced low-dose-rate gain degradation in bipolar junction transistors. Multiple-trapping simulations show that space charge limited transport is partially responsible for low-dose-rate enhancement. At low dose rates, more holes are trapped near the silicon-oxide interface than at high dose rates, resulting in larger midgap voltage shifts at lower dose rates. The additional trapped charge near the interface may cause an exponential increase in excess base current, and a resultant decrease in current gain for some NPN bipolar technologies.

Cirba, C.R.; Fleetwood, D.M.; Graves, R.J.; Michez, A.; Milanowski, R.J.; Saigne, F.; Schrimpf, R.D.; Witczak, S.C.

1998-10-26

314

Metamorphic Ga0.76In0.24As/GaAs0.75Sb0.25 tunnel junctions grown on GaAs substrates  

NASA Astrophysics Data System (ADS)

Lattice-matched and pseudomorphic tunnel junctions have been developed in the past for application in a variety of semiconductor devices, including heterojunction bipolar transistors, vertical cavity surface-emitting lasers, and multijunction solar cells. However, metamorphic tunnel junctions have received little attention. In 4-junction Ga0.51In0.49P/GaAs/Ga0.76In0.24As/Ga0.47In0.53As inverted-metamorphic solar cells (4J-IMM), a metamorphic tunnel junction is required to series connect the 3rd and 4th junctions. We present a tunnel junction based on a metamorphic Ga0.76In0.24As/GaAs0.75Sb0.25 structure for this purpose. This tunnel junction is grown on a metamorphic Ga0.76In0.24As template on a GaAs substrate. The band offsets in the resulting type-II heterojunction are calculated using the first-principles density functional method to estimate the tunneling barrier height and assess the performance of this tunnel junction against other material systems and compositions. The effect of the metamorphic growth on the performance of the tunnel junctions is analyzed using a set of metamorphic templates with varied surface roughness and threading dislocation density. Although the metamorphic template does influence the tunnel junction performance, all tunnel junctions measured have a peak current density over 200 A/cm2. The tunnel junction on the best template has a peak current density over 1500 A/cm2 and a voltage drop at 15 A/cm2 (corresponding to operation at 1000 suns) lower than 10 mV, which results in a nearly lossless series connection of the 4th junction in the 4J-IMM structure.

García, I.; Geisz, J. F.; France, R. M.; Kang, J.; Wei, S.-H.; Ochoa, M.; Friedman, D. J.

2014-08-01

315

Pleated metal bipolar assembly  

DOEpatents

A thin low-cost bipolar plate for an electrochemical cell is formed from a polymer support plate with first flow channels on a first side of the support plate and second flow channels on a second side of the support plate, where the first flow channels and second flow channels have intersecting locations and have a depth effective to form openings through the support plate at the intersecting locations. A first foil of electrically conductive material is pressed into the first flow channels. A second foil of electrically conductive material pressed into the second flow channels so that electrical contact is made between the first and second foils at the openings through the support plate. A particular application of the bipolar plate is in polymer electrolyte fuel cells.

Wilson, Mahlon S. (Los Alamos, NM); Zawodzinski, Christine (Los Alamos, NM)

2001-01-01

316

431 531 Class Notes 5 5 Transistors and Transistor Circuits  

E-print Network

431 531 Class Notes 5 5 Transistors and Transistor Circuits Although I will not follow the text in detail for the discussion of transistors, I will follow the text's philosophy. Unless one gets into device fabrication, it is generally not important to understand the inner workings of transistors

Frey, Raymond E.

317

Reduced-dimension transistors: Reduced-dimension transistors  

E-print Network

1 Reduced-dimension transistors: the HEMT LECTURE 20 · Reduced-dimension transistors · HEMT · 2-D;2 Examples of 3-, 2- and 1-D transistors #12;3 High electron-mobility Transistor · Note the Schottky barrier

Pulfrey, David L.

318

Printed Organic Transistors  

Microsoft Academic Search

We use scalable printing technology in the fabrication of the organic transistors. We formulated printable conducting layers that can be imaged onto a transistor structures forming source and drains lines with 10 micron wide channels. The performance of printed transisors compare compare favorable with those prepared using metal contacts evaporated via shadow mask

Graciela Blanchet; Gao Feng; Curtis Fincher; John Rogers; Loo Lin

2002-01-01

319

Electrolytic Analog Transistor  

Microsoft Academic Search

The electrolytic analog transistor is an operating model of the junction transistor which substitutes the reduced and oxidized forms of ions in solution for electrons and holes in a semiconductor. A base electrode makes a low-resistance contact to the solution and also serves to maintain the ratio of oxidized and reduced ions at an equilibrium value, thus establishing the potential

Harry Letaw Jr.; John Bardeen

1954-01-01

320

[Creativity and bipolar disorder].  

PubMed

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. PMID:24590850

Maçkal?, Zeynep; Gülöksüz, Sinan; Oral, Timuçin

2014-01-01

321

The immunology of bipolar disorder  

PubMed Central

Bipolar disorder is a psychiatric condition associated with elevated frequency of clinical co-morbidities and cognitive impairment. The neurobiology of bipolar disorder is not completely understood. Recent evidence has implicated immune dysfunction in its physiopathology. Here, we review several data supporting the presence of immunological dysfunction in bipolar disorder: (i) increased frequency of autoimmune diseases; (ii) distinct immune cells profile; (iii) altered/ release of cytokines by stimulated mononuclear cells; (iv) elevated levels of circulating immune markers; and (vi) inflammatory changes in the central nervous system. We also discussed the interplay between immunological dysfunction and neuroprogression in bipolar disorder. PMID:24557044

Barbosa, Izabela Guimarães; Machado-Vieira, Rodrigo; Soares, Jair C; Teixeira, Antonio L

2014-01-01

322

An ultrawideband spin-wave medium-power chaos generator based on field-effect transistors  

NASA Astrophysics Data System (ADS)

A prototype of an ultrawideband (UWB) microwave chaos generator based on a nonlinear spin-wave transmission line, a multistage transistor amplifier with an output amplifier based on GaAs field-effect transistors, and a microstrip bandpass filter was constructed. The possibility of autonomous generation of a UWB chaotic microwave signal with a central frequency of 3 GHz and a total power of about 4 W in a frequency band exceeding 30% was demonstrated. The proposed chaos generator is characterized by a fairly high efficiency of about 20%.

Grishin, S. V.; Grishin, V. S.; Romanenko, D. V.; Sharaevskii, Yu. P.

2014-10-01

323

Single Photon Transistor Brad Martin  

E-print Network

Single Photon Transistor Brad Martin PH 464 #12;Brad Martin Single Photon Transistor 1 Abstract The concept of an optical transistor is not a new one. The difficulty with building optical devices that use in the nanowire. This concept can be extended to create an optical transistor device in which "current"(a flow

La Rosa, Andres H.

324

A 22 Gb\\/s decision circuit and a 32 Gb\\/s regenerating demultiplexer IC fabricated in silicon bipolar technology  

Microsoft Academic Search

A decision circuit and a 1:2 regenerating demultiplexer, which are key components in optical-fiber transmission links, were fabricated in an advanced self-aligning silicon bipolar technology using 0.8-?m lithography. Maximum speed rather than low power consumption was the main goal of these designs. The transistors were individually optimized using a semiphysical transistor model for circuit simulation. At such high operating speeds

J. HauenschildlJ; A. Felder; M. Kerber; H.-M. Rein; L. Schmidt

1992-01-01

325

Legal Issues of Pediatric Bipolar Disorder  

MedlinePLUS

... Bipolar? What is Depression? Bipolar Facts Downloadable MP3's Celebrities Talk to Teens Podcast: Listen to the Flipswitch Podcast ... Notices & Disclaimers Privacy policy Technical Help Copyright © 2000- ...

326

Impact of Arsenic Related Defects on Electronic Performance of ZrO2/GaAs: Density Functional Theory Calculations  

NASA Astrophysics Data System (ADS)

Arsenic can diffuse into high-? dielectrics during GaAs-based metal oxide semiconductor transistor process, which causes the degradation of gate dielectrics. To explore the origins of the degradation, we employ nonlocal B3LYP hybrid functional to study arsenic related defects in ZrO2. Via band alignments between the GaAs and ZrO2, we are able to determine the defect formation energy in the GaAs relative to the ZrO2 band gap and assess how they will affect the device performance. Arsenic at the interstitial site serves as a source of positive fixed charge while at the oxygen or zirconium substitutional site changes its charge state within the band gap of GaAs. Moreover, it is found that arsenic related defects produce conduction band offset reduction and gap states, which will increase the gate leakage current.

Wang, Yu-Peng; Wang, Yong-Ping; Shi, Li-Bin

2015-01-01

327

Fast-switching insulated gate transistors  

NASA Astrophysics Data System (ADS)

Insulated gate transistors (IGT's), which have been developed on the basis of an integration of MOS and bipolar technologies, represent a new class of semiconductor power-switching devices. The IGT devices reported by Baliga et al. (1982) have, however, one disadvantage, which is related to a slow switching speed. The present investigation is concerned with the development of improved high-speed switching IGT devices. The improved switching speed is attained by making use of high-energy radiation to reduce the minority-carrier lifetime. The IGT devices employed in the considered study were fabricated with the aid of the n-channel polysilicon gate DMOS process. Attention is given to details regarding the experimental procedure and the device characteristics.

Baliga, B. J.

1983-12-01

328

Microwave operation of GaN\\/AlGaN-doped channel heterostructure field effect transistors  

Microsoft Academic Search

We report on the microwave operation of 1 ?m gate AlGaN\\/GaN doped channel heterostructure field effect transistors (DC-HFET's) with the cutoff frequency fT of 18.3 GHz. These devices exhibit the cutoff frequency-gate length product in excess of 18 GHz·?m, comparable to that of the state-of-the-art GaAs MESFET's. We explain these improvements in the device performance by the increased sheet carrier

M. Asif Khan; Q. Chen; J. W. Yang; Michael S. Shur; B. T. Dermott; J. A. Higgins

1996-01-01

329

Effect of bulk inversion asymmetry on the Datta-Das transistor  

NASA Astrophysics Data System (ADS)

A model of the Datta-Das spin field-effect transistor is presented which, in addition to the Rashba interaction, takes into account the influence of bulk inversion asymmetry of zinc-blende semiconductors. In the presence of bulk inversion asymmetry, the conductance is found to depend significantly on the crystallographic orientation of the channel. We determine the channel direction optimal for the observation of the Datta-Das effect in GaAs- and InAs-based devices.

?usakowski, A.; Wróbel, J.; Dietl, T.

2003-08-01

330

Dysfunctional assumptions in bipolar disorder  

Microsoft Academic Search

Background: Despite the initial encouraging outcome in developing CBT for bipolar affective disorder [Arch. Gen. Psychiatry 2002 (in press); Psychol. Med. 31 (2001) 459–467], very little is known about whether there are any differences in dysfunctional attitudes between unipolar and bipolar patients. Both the behavioural activation system theory [J. Pers. Soc. Psychol. 67 (1994) 488–498; Major Theories of Personality Disorder,

Dominic Lam; Kim Wright; Neil Smith

2004-01-01

331

A comparison of radiation damage in transistors from cobalt-60 gamma rays and 2.2 MeV electrons  

NASA Technical Reports Server (NTRS)

The total ionizing dose response of ten bipolar transistor types has been measured using Co-60 gamma rays and 2.2 MeV electrons from exposure levels of 750, 1500, and 3000 Gy(Si). Gain measurements were made for a range of collector-emitter voltages and collector currents.

Nichols, D. K.; Price, W. E.; Gauthier, M. K.

1982-01-01

332

Printed inorganic transistors  

E-print Network

Forty years of exponential growth of semiconductor technology have been predicated on the miniaturization of the transistors that comprise integrated circuits. While complexity has greatly increased within a given area of ...

Ridley, Brent (Brent Alan), 1974-

2003-01-01

333

The resonant gate transistor  

Microsoft Academic Search

A device is described which permits high-Qfrequency selection to be incorporated into silicon integrated circuits. It is essentially an electrostatically excited tuning fork employing field-effect transistor \\

HARVEY C. NATHANSON; WILLIAM E. NEWELL; ROBERT A. WICKSTROM

1967-01-01

334

The Transistor Game  

NSDL National Science Digital Library

In this game, your job working at a Transistor Recycling Centre is to ensure that only items containing transistors are sent to the recycling machine. Goods enter the recycling machine via a conveyer belt, and you must remove all the items that do not contain transistors. You are awarded one point for each item that you correctly remove from the belt. If you mistakenly remove an item with a transistor, two points will be deducted from your total score. The game has an infinite number of levels, and you will be evaluated at the end of each level. When you have completed one level you can move onto the next, in which the belt moves faster and there will be new items to sort. If you're really skilled you could become this month's super recycler!

335

High Power Switching Transistor  

NASA Technical Reports Server (NTRS)

Improved switching transistors handle 400-A peak currents and up to 1,200 V. Using large diameter silicon wafers with twice effective area as D60T, form basis for D7 family of power switching transistors. Package includes npn wafer, emitter preform, and base-contact insert. Applications are: 25to 50-kilowatt high-frequency dc/dc inverters, VSCF converters, and motor controllers for electrical vehicles.

Hower, P. L.; Kao, Y. C.; Carnahan, D. C.

1983-01-01

336

Bipolar pulse forming line  

DOEpatents

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.

Rhodes, Mark A. (Pleasanton, CA)

2008-10-21

337

Novel Design of Vertical Double-Diffused Metal-Oxide-Semiconductor Transistor for High Electrostatic Discharge Robustness  

NASA Astrophysics Data System (ADS)

[Bipolar]-[complementary metal-oxide-semiconductor transistor (CMOS)]-[double-diffused metal-oxide-semiconductor transistor (DMOS)] [BiC-DMOS] devices are widely used in high-voltage applications. As some applications require high electrostatic discharge (ESD) robustness, we studied the vertical DMOS (VDMOS) transistor to improve ESD robustness. In this paper, we propose a balanced VDMOS (B-VDMOS) transistor. A B-VDMOS transistor is optimized for a cell layout to improve current uniformity after avalanche breakdown by arranging a number of sources. As the B-VDMOS transistor can prevent current concentration, it is not destroyed after avalanche breakdown and acquires a high second breakdown current. Owing to the high second breakdown current, the B-VDMOS transistor can improve ESD robustness by 50% according to the human body model (HBM) test compared with a conventional VDMOS (C-VDMOS) transistor. As the B-VDMOS transistor has high ESD robustness, it can be used in harsh applications and systems.

Hatasako, Kenichi; Yamamoto, Fumitoshi; Uenishi, Akio; Kuroi, Takashi; Maegawa, Shigeto

2009-04-01

338

Bipolar Disorder Among Children Overall Prevalence  

E-print Network

Bipolar Disorder Among Children Overall Prevalence · Bipolar Disorder usually starts in late adolescence or early adulthood, but children can have bipolar disorder too. · Community studies estimate lifetime prevalence of bipolar spectrum disorders to be 0% to 3% among adolescents, depending

Baker, Chris I.

339

Transistor-based interface circuitry  

DOEpatents

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.

Taubman, Matthew S. (Richland, WA)

2007-02-13

340

Transistor-based interface circuitry  

DOEpatents

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.

Taubman, Matthew S. (Richland, WA)

2004-02-24

341

Effect of 100MeV oxygen ion irradiation on silicon NPN power transistor  

SciTech Connect

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.

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

342

Development of a HgCdTe photomixer and impedance matched GaAs FET amplifier  

NASA Technical Reports Server (NTRS)

A research program for the development of a 10.6 micron HgCdTe photodiode/GaAs field effect transistor amplifier package for use at cryogenic temperatures (77k). The photodiode/amplifier module achieved a noise equivalent power per unit bandwidth of 5.7 times 10 to the 20th power W/Hz at 2.0 GHz. The heterodyne sensitivity of the HgCdTe photodiode was improved by designing and building a low noise GaAs field effect transistor amplifier operating at 77K. The Johnson noise of the amplifier was reduced at 77K, and thus resulted in an increased photodiode heterodyne sensitivity.

Shanley, J. F.; Paulauskas, W. A.; Taylor, D. R.

1982-01-01

343

[Revisiting bipolar disorder].  

PubMed

According to the theory of evolution of Charles Darwin which is an author of The Origin of Species, human being evolves after long time to be profitable to "prosperity of a kind", and it is thought that there is the adaptive meaning. In other words, man stand on various creatures in number, and it may be said that human being building a high civilized society is the creature which was able to have an element of chosen mind and body in natural selection. However, a disease does not disappear from our daily life and tends to consider us to be "the misfortune" even if we human being is easy to suffer from a disease. "Evolution medicine" (Darwinian medicine) drop hint of meaning/the significance in aging and the process of the pathology. This paper refers to such a conception of bipolar disorder. PMID:17877000

Senjyu, Yoshika; Ozawa, Hiroki

2007-09-01

344

Genetics of bipolar disorder  

PubMed Central

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 psychiatric disorders should be established. PMID:24683306

Kerner, Berit

2014-01-01

345

Bipolar electrodissection tonsillectomy in children.  

PubMed

The purpose of this study was to compare bipolar electrodissection tonsillectomy with traditional cold dissection tonsillectomy in the pediatric population. Forty children with recurrent tonsillitis and/or obstructive symptoms were included in the study. The study population was randomly divided into two groups, and the two techniques were compared with regard to operative time, intraoperative and postoperative bleeding and postoperative pain. There were 23 children in the bipolar electrodissection tonsillectomy group (mean age, 8.1 years; range, 5-12 years), and 17 children in the cold dissection tonsillectomy group (mean age, 6.7 years; range, 5-12 years). The average operative times were 15.2+/-8.5 min for bipolar electrodissection tonsillectomy and 29.06+/-13.5 min for cold dissection tonsillectomy (P < 0.05). The blood loss in bipolar electrodissection tonsillectomy and cold dissection tonsillectomy was 5.0+/-4.2 ml and 32.1+/-11.3 ml, respectively (P < 0.05). Postoperative hemorrhage was not observed. Bipolar electrodissection tonsillectomy was less painful the first 30 min postoperatively (P < 0.05). Bipolar electrodissection tonsillectomy in children is a useful technique, with results comparable to traditional cold dissection tonsillectomy. PMID:16133467

Kirazli, Tayfun; Bilgen, Cem; Midilli, Rasit; Ogüt, Fatih; Uyar, Meltem; Kedek, Aysegül

2005-09-01

346

Quantum functional devices - Resonant-tunneling transistors, circuits with reduced complexity, and multiple-valued logic  

Microsoft Academic Search

Recent advances in the area of quantum functional devices are discussed. After a discussion of the functional device concept, resonant-tunneling bipolar transistors (RTBTs) with a double barrier in the base region are described. Design considerations for RTBTs with ballistic injection and the first observation of minority-electron ballistic RT are presented. RTBTs using thermionic injection and exhibiting a high peak-to-valley ratio

Federico Capasso; Susanta Sen; Fabio Beltram; Leda M. Lunardi; Arvind S. Vengurlekar; P. R. Smith; N. J. Shah; R. J. Malik; A. Y. Cho

1989-01-01

347

Nanowire transistors without junctions.  

PubMed

All existing transistors are based on the use of semiconductor junctions formed by introducing dopant atoms into the semiconductor material. As the distance between junctions in modern devices drops below 10 nm, extraordinarily high doping concentration gradients become necessary. Because of the laws of diffusion and the statistical nature of the distribution of the doping atoms, such junctions represent an increasingly difficult fabrication challenge for the semiconductor industry. Here, we propose and demonstrate a new type of transistor in which there are no junctions and no doping concentration gradients. These devices have full CMOS functionality and are made using silicon nanowires. They have near-ideal subthreshold slope, extremely low leakage currents, and less degradation of mobility with gate voltage and temperature than classical transistors. PMID:20173755

Colinge, Jean-Pierre; Lee, Chi-Woo; Afzalian, Aryan; Akhavan, Nima Dehdashti; Yan, Ran; Ferain, Isabelle; Razavi, Pedram; O'Neill, Brendan; Blake, Alan; White, Mary; Kelleher, Anne-Marie; McCarthy, Brendan; Murphy, Richard

2010-03-01

348

ORIGINAL PAPER Olfactory identification and preference in bipolar disorder  

E-print Network

ORIGINAL PAPER Olfactory identification and preference in bipolar disorder and schizophrenia Amanda and olfactory preference in schizophrenia and bipolar disorder. Individuals with schizophrenia or bipolar schizophrenic and bipolar groups showed olfactory iden- tification deficits compared with the healthy controls

Palmeri, Thomas

349

Hydrodynamic Models of Bipolar Semiconductors Best Asymptotic Profiles  

E-print Network

Hydrodynamic Models of Bipolar Semiconductors Best Asymptotic Profiles Convergence to Stationary Waves Asymptotic Profiles for Bipolar Hydrodynamic System of Semiconductors Ming Mei Champlain College for Bipolar Hydrodynamic System of Semicon #12;Hydrodynamic Models of Bipolar Semiconductors Best Asymptotic

350

Polariton Condensate Transistor Switch  

E-print Network

A polariton condensate transistor switch is realized through optical excitation of a microcavity ridge with two beams. The ballistically ejected polaritons from a condensate formed at the source are gated using the 20 times weaker second beam to switch on and off the flux of polaritons. In the absence of the gate beam the small built-in detuning creates potential landscape in which ejected polaritons are channelled toward the end of the ridge where they condense. The low loss photon-like propagation combined with strong nonlinearities associated with their excitonic component makes polariton based transistors particularly attractive for the implementation of all-optical integrated circuits.

Gao, T; Liew, T C H; Tsintzos, S I; Stavrinidis, G; Deligeorgis, G; Hatzopoulos, Z; Savvidis, P G

2012-01-01

351

Single electron transistor in pure silicon  

NASA Astrophysics Data System (ADS)

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 interaction plays a significant role. The observed amplitude spectrum suggests the spin blockade effect. When the two-electron system forms a singlet state in the dot at low fields, and the injection current from the lead becomes spin-down polarized, the tunneling conductance is reduced by a factor of 8. At higher magnetic fields, due to the ST transition, the spin blockade effect is lifted and the conductance is fully recovered.

Hu, Binhui

352

GaAs solar cell development  

NASA Technical Reports Server (NTRS)

The motivation for developing GaAs solar cells is based on their superior efficiency when compared to silicon cells, their lower degradation with increasing temperature, and the expectation for better resistance to space radiation damage. The AMO efficiency of GaAs solar cells was calculated. A key consideration in the HRL technology is the production of GaAs cells of large area (greater than 4 sg cm) at a reasonable cost without sacrificing efficiency. An essential requirement for the successful fabrication of such cells is the ability to grow epitaxially a uniform layer of high quality GaAs (buffer layer) on state-of-the-art GaAs substrates, and to grow on this buffer layer the required than layer of (AlGa)As. A modified infinite melt liquid phase epitaxy (LPE) growth technique is detailed.

Knechtli, R. C.; Kamath, S.; Loo, R.

1977-01-01

353

Dual-Side Wafer Processing and Resonant Tunneling Transistor Applications  

SciTech Connect

We describe dual-side wafer processing and its application to resonant tunneling transistors in a planar configuration. The fabrication technique utilizes a novel flip-chip, wafer thinning process called epoxy-bond and stop-etch (EBASE) process, where the substrate material is removed by selective wet etching and stopped at an etch-stop layer. This EBASE method results in a semiconductor epitaxial layer that is typically less than a micron thick and has a mirror-finish, allowing backside gates to be placed in close proximity to frontside gates. Utilizing this technique, a resonant tunneling transistor--the double electron layer tunneling transistor (DELTT)--can be fabricated in a fully planar configuration, where the tunneling between two selectively-contacted 2DEGs in GaAs or InGaAs quantum wells is modulated by surface Schottky gate. Low temperature electrical characterization yields source-drain I-V curves with a gate-tunable negative differential resistance.

Moon, J.S.; Simmons, J.A.; Wendt, J.R.; Hietala, V.M.; Reno, J.L.; Baca, W.E.; Blount, M.A.

1999-07-20

354

Integrated neurobiology of bipolar disorder.  

PubMed

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 bipolarity is one of the great questions facing the field and one that is likely to have profound treatment implications, given that fact that such a discovery would greatly increase our ability to individualize - and by extension, enhance - treatment. PMID:25202283

Maletic, Vladimir; Raison, Charles

2014-01-01

355

The Genetics of Bipolar Disorder  

PubMed Central

Bipolar disorder is a mood disorder characterized by impairing episodes of mania and depression. Twin studies have established that bipolar disorder is among the most heritable of medical disorders and efforts to identify specific susceptibility genes have intensified over the past two decades. The search for genes influencing bipolar disorder has been complicated by a paucity of animal models, limited understanding of pathogenesis, and the genetic and phenotypic complexity of the syndrome. Linkage studies have implicated several chromosomal regions as harboring relevant genes, but results have been inconsistent. It is now widely accepted that the genetic liability to bipolar disorder reflects the action of many genes of individually small effect, a scenario for which linkage studies are poorly suited. Thus, association studies, which are more powerful for the detection of modest effect loci, have become the focus of gene-finding research. A large number of candidate genes, including biological candidates derived from hypotheses about the pathogenesis of the disorder and positional candidates derived from linkage and cytogenetic studies, have been evaluated. Several of these genes have been associated with the disorder in independent studies (including BDNF, DAOA, DISC1, GRIK4, SLC6A4, and TPH2), but none has been established. The clinical heterogeneity of bipolar disorder and its phenotypic and genetic overlap with other disorders (especially schizophrenia, schizoaffective disorder, and major depressive disorder) has raised questions about the optimal phenotype definition for genetic studies. Nevertheless, genomewide association analysis, which has successfully identified susceptibility genes for a variety of complex disorders, has begun to implicate specific genes for bipolar disorder (DGKH, CACNA1C, ANK3). The polygenicity of the disorder means that very large samples will be needed to detect the modest effect loci that likely contribute to bipolar disorder. Detailed genetic dissection of the disorder may provide novel targets (both pharmacologic and psychosocial) for intervention. PMID:19358880

Barnett, Jennifer H; Smoller, Jordan W

2009-01-01

356

Treatment of bipolar disorder  

PubMed Central

We review recent developments in the acute and long-term treatment of bipolar disorder and identify promising future routes to therapeutic innovation. Overall, advances in drug treatment remain quite modest. Antipsychotic drugs are effective in the acute treatment of mania; their efficacy in the treatment of depression is variable with the clearest evidence for quetiapine. Despite their widespread use, considerable uncertainty and controversy remains about the use of antidepressant drugs in the management of depressive episodes. Lithium has the strongest evidence for long-term relapse prevention; the evidence for anticonvulsants such as divalproex and lamotrigine is less robust and there is much uncertainty about the longer term benefits of antipsychotics. Substantial progress has been made in the development and assessment of adjunctive psychosocial interventions. Long-term maintenance and possibly acute stabilisation of depression can be enhanced by the combination of psychosocial treatments with drugs. The development of future treatments should consider both the neurobiological and psychosocial mechanisms underlying the disorder. We should continue to repurpose treatments and to recognise the role of serendipity. We should also investigate optimum combinations of pharmacological and psychotherapeutic treatments at different stages of the illness. Clarification of the mechanisms by which different treatments affect sleep and circadian rhythms and their relation with daily mood fluctuations is likely to help with the treatment selection for individual patients. To be economically viable, existing psychotherapy protocols need to be made briefer and more efficient for improved scalability and sustainability in widespread implementation. PMID:23663953

2013-01-01

357

Bipolar (Spectrum) Disorder and Mood Stabilization: Standing at the Crossroads?  

Microsoft Academic Search

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

Jürgen De Fruyt; Koen Demyttenaere

2007-01-01

358

Temporal order of bipolar cell genesis in the neural retina  

Microsoft Academic Search

BACKGROUND: Retinal bipolar cells comprise a diverse group of neurons. Cone bipolar cells and rod bipolar cells are so named for their connections with cone and rod photoreceptors, respectively. Morphological criteria have been established that distinguish nine types of cone bipolar cells and one type of rod bipolar cell in mouse and rat. While anatomical and physiological aspects of bipolar

Eric M Morrow; C-M Amy Chen; Constance L Cepko

2008-01-01

359

A Matterwave Transistor Oscillator  

E-print Network

A triple-well atomtronic transistor combined with forced RF evaporation is used to realize a driven matterwave oscillator circuit. The transistor is implemented using a metalized compound glass and silicon substrate. On-chip and external currents produce a cigar-shaped magnetic trap, which is divided into transistor source, gate, and drain regions by a pair of blue-detuned optical barriers projected onto the magnetic trap through a chip window. A resonant laser beam illuminating the drain portion of the atomtronic transistor couples atoms emitted by the gate to the vacuum. The circuit operates by loading the source with cold atoms and utilizing forced evaporation as a power supply that produces a positive chemical potential in the source, which subsequently drives oscillation. High-resolution in-trap absorption imagery reveals gate atoms that have tunneled from the source and establishes that the circuit emits a nominally mono-energetic matterwave with a frequency of 23.5(1.0) kHz by tunneling from the gate, ...

Caliga, Seth C; Zozulya, Alex A; Anderson, Dana Z

2012-01-01

360

A Matterwave Transistor Oscillator  

E-print Network

An atomtronic transistor circuit is used to realize a driven matterwave oscillator. The transistor consists of Source and Drain regions separated by a narrow Gate well. Quasi-steady-state behavior is determined from a thermodynamic model, which reveals two oscillation threshold regimes. One is due to the onset of Bose-Einstein condensation in the Gate well, the other is due to the appearance of a negative transresistance regime of the transistor. The thresholds of oscillation are shown to be primarily dependent on the potential energy height difference between Gate-Drain and Gate-Source barriers. The transistor potential is established with a combination of magnetic and optical fields using a compound glass and silicon substrate atom chip. The onset of oscillation and the output matterwave are observed through in-trap imaging. Time-of-flight absorption imaging is used to determine the time dependence of the Source well thermal and chemical energies as well as to estimate the value of the closed-loop ohmic Gate resistance, which is negative and is observed to cause cooling of Source atoms.

Seth C. Caliga; Cameron J. E. Straatsma; Alex A. Zozulya; Dana Z. Anderson

2013-09-13

361

Transistor Fundamentals: The MOSFET  

NSDL National Science Digital Library

Created by Patrick Hoppe of the Wisconsin Online Resource Center this is an introduction to the metal oxide semiconductor field effect transistor (MOSFET). Along with a general introduction, students also examine its enhancement mode. This is a nice brief introduction to the topic.

Hoppe, Patrick

362

Multimode Silicon Nanowire Transistors  

PubMed Central

The combined capabilities of both a nonplanar design and nonconventional carrier injection mechanisms are subject to recent scientific investigations to overcome the limitations of silicon metal oxide semiconductor field effect transistors. In this Letter, we present a multimode field effect transistors device using silicon nanowires that feature an axial n-type/intrinsic doping junction. A heterostructural device design is achieved by employing a self-aligned nickel-silicide source contact. The polymorph operation of the dual-gate device enabling the configuration of one p- and two n-type transistor modes is demonstrated. Not only the type but also the carrier injection mode can be altered by appropriate biasing of the two gate terminals or by inverting the drain bias. With a combined band-to-band and Schottky tunneling mechanism, in p-type mode a subthreshold swing as low as 143 mV/dec and an ON/OFF ratio of up to 104 is found. As the device operates in forward bias, a nonconventional tunneling transistor is realized, enabling an effective suppression of ambipolarity. Depending on the drain bias, two different n-type modes are distinguishable. The carrier injection is dominated by thermionic emission in forward bias with a maximum ON/OFF ratio of up to 107 whereas in reverse bias a Schottky tunneling mechanism dominates the carrier transport. PMID:25303290

2014-01-01

363

Radiation-hardened transistor and integrated circuit  

DOEpatents

A composite transistor is disclosed for use in radiation hardening a CMOS IC formed on an SOI or bulk semiconductor substrate. The composite transistor has a circuit transistor and a blocking transistor connected in series with a common gate connection. A body terminal of the blocking transistor is connected only to a source terminal thereof, and to no other connection point. The blocking transistor acts to prevent a single-event transient (SET) occurring in the circuit transistor from being coupled outside the composite transistor. Similarly, when a SET occurs in the blocking transistor, the circuit transistor prevents the SET from being coupled outside the composite transistor. N-type and P-type composite transistors can be used for each and every transistor in the CMOS IC to radiation harden the IC, and can be used to form inverters and transmission gates which are the building blocks of CMOS ICs.

Ma, Kwok K. (Albuquerque, NM)

2007-11-20

364

Early onset bipolar disorder Early Onset Bipolar Disorder: validation from admixture analyses and biomarkers.  

E-print Network

Early onset bipolar disorder 1 Early Onset Bipolar Disorder: validation from admixture analyses of Psychiatry / Revue Canadienene de Psychiatrie 2013;58(4):240-248" #12;Early onset bipolar disorder 2 Abstract: Objectives: Bipolar affective disorder (BD) is a multifactorial disorder with heterogeneous clinical

Paris-Sud XI, Université de

365

Bipolar magnetic structures driven by stratified turbulence with a coronal envelopeBIPOLAR MAGNETIC STRUCTURES  

E-print Network

Bipolar magnetic structures driven by stratified turbulence with a coronal envelopeBIPOLAR MAGNETIC of bipolar magnetic structures in direct numerical simulations of stratified forced turbulence with an outer to the turbulent layer. After ::::::: about some 1­2 turbulent diffusion times, a bipolar magnetic region

Brandenburg, Axel

366

Enhanced Radiation Sensitivity in Short-Channel Partially Depleted Silicon-on-Insulator n-Type Metal-Oxide-Semiconductor Field Effect Transistors  

NASA Astrophysics Data System (ADS)

The total ionizing dose effects of partially depleted silicon-on-insulator (SOI) transistors in a 0.13 ?m technology are studied by 60Co ?-ray irradiation. Radiation enhanced drain-induced barrier lowering (DIBL) under different bias conditions is related to the parasitic bipolar in the SOI transistor and oxide trapped charge in the buried oxide, and it is experimentally observed for short channel transistors. The enhanced DIBL effect manifests as the DIBL parameter increases with total dose. Body doping concentration is a key factor affecting the total ionizing dose effect of the transistor. The low body doping transistor exhibits not only significant front gate threshold voltage shift as a result of the coupling effect, but also great off-state leakage at high drain voltage due to the enhanced DIBL effect.

Peng, Chao; Zhang, Zheng-Xuan; Hu, Zhi-Yuan; Huang, Hui-Xiang; Ning, Bing-Xu; Bi, Da-Wei

2013-09-01

367

Modulating the Morphology and Electrical Properties of GaAs Nanowires via Catalyst Stabilization by Oxygen.  

PubMed

Nowadays, III-V compound semiconductor nanowires (NWs) have attracted extensive research interest because of their high carrier mobility favorable for next-generation electronics. However, it is still a great challenge for the large-scale synthesis of III-V NWs with well-controlled and uniform morphology as well as reliable electrical properties, especially on the low-cost noncrystalline substrates for practical utilization. In this study, high-density GaAs NWs with lengths >10 ?m and uniform diameter distribution (relative standard deviation ? ? 20%) have been successfully prepared by annealing the Au catalyst films (4-12 nm) in air right before GaAs NW growth, which is in distinct contrast to the ones of 2-3 ?m length and widely distributed of ? ? 20-60% of the conventional NWs grown by the H2-annealed film. This air-annealing process is found to stabilize the Au nanoparticle seeds and to minimize Ostwald ripening during NW growth. Importantly, the obtained GaAs NWs exhibit uniform p-type conductivity when fabricated into NW-arrayed thin-film field-effect transistors (FETs). Moreover, they can be integrated with an n-type InP NW FET into effective complementary metal oxide semiconductor inverters, capable of working at low voltages of 0.5-1.5 V. All of these results explicitly demonstrate the promise of these NW morphology and electrical property controls through the catalyst engineering for next-generation electronics. PMID:25700210

Han, Ning; Yang, Zaixing; Wang, Fengyun; Yip, SenPo; Dong, Guofa; Liang, Xiaoguang; Hung, TakFu; Chen, Yunfa; Ho, Johnny C

2015-03-11

368

Mathematical Models of Bipolar Disorder  

E-print Network

We use limit cycle oscillators to model Bipolar II disorder, which is characterized by alternating hypomanic and depressive episodes and afflicts about one percent of the United States adult population. We consider two nonlinear 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.

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

2004-06-16

369

Mathematical models of bipolar disorder  

NASA Astrophysics Data System (ADS)

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.

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

2009-07-01

370

Neurobiological basis of bipolar disorder Tadafumi Kato  

E-print Network

Neurobiological basis of bipolar disorder Tadafumi Kato Laboratory for Molecular Dynamics of Mental Disorders, RIKEN Brain Science Institute Bipolar disorder is characterized by recurrent episodes of mania channel genes including CACNA1C. Mendelian diseases accompanying bipolar disorder or depression include

Fukai, Tomoki

371

Fuel Cell Stack Components BipolarPlate  

E-print Network

OXYGEN Example shown is for acidic electrolytes BipolarPlate e - e - O2 O2 O2 e - H+ BipolarPlateBipolarPlate e -e - e -e - O2O2 O2O2 O2O2 e -e - H+H+ Power Nancy GarlandNancy Garland #12;Targets 500 @ 0.75 Vm

372

Handling bipolar knowledge with imprecise probabilities  

E-print Network

Handling bipolar knowledge with imprecise probabilities Sébastien Destercke December 15, 2011 Abstract Information is said to be bipolar when it has a positive and a negative part. The problem of representing and processing such bipolar information has recently received a lot of attention in uncertainty

Paris-Sud XI, Université de

373

BIPOLAR COXETER GROUPS Pierre-Emmanuel Capracea  

E-print Network

BIPOLAR COXETER GROUPS Pierre-Emmanuel Capracea & Piotr Przytyckib a Universit´e catholique de these Coxeter groups bipolar. They include the virtually Poincar´e dual- ity Coxeter groups, the pseudo-manifold Coxeter groups and the infinite irreducible 2-spherical ones. We show in a geometric way that a bipolar

Caprace, Pierre-Emmanuel

374

Metallic Bipolar Plates with Composite Coatings  

E-print Network

Metallic Bipolar Plates with Composite Coatings Jennifer Mawdsley Argonne National Laboratory Fuel Cell Projects Kickoff Meeting Washington DC October 1, 2009 #12;2 Metallic Bipolar Plates with Composite Coatings Project Objective Make aluminum-based bipolar plates an option for replacing machined

375

Is bipolar always bipolar? Understanding the controversy on bipolar disorder in children  

PubMed Central

Dramatically increasing prevalence rates of bipolar disorder in children and adolescents in the United States have provoked controversy regarding the boundaries of manic symptoms in child and adolescent psychiatry. The serious impact of this ongoing debate on the treatment of affected children is reflected in the concomitant increase in prescription rates for antipsychotic medication. A key question in the debate is whether this increase in bipolar disorder in children and adolescents is based on a better detection of early-onset bipolar disorder—which can present differently in children and adolescents—or whether it is caused by an incorrect assignment of symptoms which overlap with other widely known disorders. So far, most findings suggest that the suspected symptoms, in particular chronic, non-episodic irritability (a mood symptom presenting with easy annoyance, temper tantrums and anger) do not constitute a developmental presentation of childhood bipolar disorder. Additional research based on prospective, longitudinal studies is needed to further clarify the developmental trajectories of bipolar disorder and the diagnostic status of chronic, non-episodic irritability. PMID:25580265

Grimmer, Yvonne; Hohmann, Sarah

2014-01-01

376

Bipolar lead acid battery development  

NASA Technical Reports Server (NTRS)

A modular bipolar battery configuration is under development at Johnson Control, Inc. (JCI) and the Jet Propulsion Laboratory (JPL). The battery design, incorporating proven lead acid electrochemistry, yields a rechargeable, high-power source that is light weight and compact. This configuration offers advantages in power capability, weight, and volume over conventional monopolar batteries and other battery chemistries. The lead acid bipolar battery operates in a sealed, maintenance-free mode allowing for maximum application flexibility. It is ideal for high-voltage and high-power applications.

Eskra, Michael; Vidas, Robin; Miles, Ronald; Halpert, Gerald; Attia, Alan; Perrone, David

1991-01-01

377

Improved chopper circuit uses parallel transistors  

NASA Technical Reports Server (NTRS)

Parallel transistor chopper circuit operates with one transistor in the forward mode and the other in the inverse mode. By using this method, it acts as a single, symmetrical, bidirectional transistor, and reduces and stabilizes the offset voltage.

1966-01-01

378

The microtubule transistor  

E-print Network

I point out the similarity between the microtubule experiment reported by Priel et al [Biophys. J. 90, 4639 (2006)] and the ZnO nanowire experiment of Wang et al [Nanolett. 6, 2768 (2006)]. It is quite possible that MTs are similar to a piezoelectric field effect transistor for which the role of the control gate electrode is played by the piezo-induced electric field across the width of the MT walls and their elastic bending features

H. C. Rosu

2007-03-26

379

Suicidality in Bipolar I Disorder  

ERIC Educational Resources Information Center

People with bipolar disorder are at high suicide risk. The literature suggests that suicidality is predicted by higher symptom severity and less use of pharmacological agents, but few studies have examined the joint contributions of these variables. The present study examines the conjoint contribution of symptom severity and pharmacological…

Johnson, Sheri L.; McMurrich, Stephanie L.; Yates, Marisa

2005-01-01

380

Corrosion resistant metallic bipolar plate  

DOEpatents

A corrosion resistant, electrically conductive component such as a bipolar plate for a PEM fuel cell includes 20 55% Cr, balance base metal such as Ni, Fe, or Co, the component having thereon a substantially external, continuous layer of chromium nitride.

Brady, Michael P. (Oak Ridge, TN); Schneibel, Joachim H. (Knoxville, TN); Pint, Bruce A. (Knoxville, TN); Maziasz, Philip J. (Oak Ridge, TN)

2007-05-01

381

X-ray lithography induced radiation damage in CMOS and bipolar devices  

NASA Astrophysics Data System (ADS)

Radiation effects from a synchroton x-ray lithography source on the performance degradation and long term reliability of high performance self-aligned bipolar devices and deep sub-micron CMOS devices are studied. The hot-carrier properties of the x-ray induced damage in CMOS devices, such as interface states, positive oxide charges and neutral traps have been examined. The effect of these radiation induced defects and their impact on the DRAM circuits in terms of the performance and reliability are discussed. In the self-aligned, double polysilicon bipolar transistor structure interface states and trapped charges can be generated by the radiation source in the sidewall oxide near the emitter-base junction such damage can increase the emitter-base leakage current. This increase of base current can substantially degrade the device current gain at low bias.

Wang, L. K.

1992-07-01

382

Pulse transformer for GaAs laser  

NASA Technical Reports Server (NTRS)

High-radiance gallium arsenide (GaAs) laser operating at room temperature is utilized in optical navigation system. For efficient transformer-to-laser impedance match, laser should be connected directly to pulse transformer secondary winding.

Rutz, E. M.

1976-01-01

383

Integrated Neurobiology of Bipolar Disorder  

PubMed Central

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 bipolarity is one of the great questions facing the field and one that is likely to have profound treatment implications, given that fact that such a discovery would greatly increase our ability to individualize – and by extension, enhance – treatment. PMID:25202283

Maletic, Vladimir; Raison, Charles

2014-01-01

384

Ohmic contact to GaAs semiconductor  

NASA Technical Reports Server (NTRS)

Multimetallic layers produce stable, low-resistance contacts for p-type GaAs and p-type GaAlAs devices. Contacts present no leakage problems, and their series resistance is too small to measure at 1 Sun intensity. Ohmic contacts are stable and should meet 20-year-life requirement at 150 C for GaAs combined photothermal/photovoltaic concentrators.

Hovel, H. J.; Woodall, J. M.

1980-01-01

385

Vertical gate-all-around junctionless nanowire transistors with asymmetric diameters and underlap lengths  

NASA Astrophysics Data System (ADS)

Vertical gate-all-around (GAA) junctionless nanowire transistors (JNTs) with different diameters and underlap lengths are investigated using three-dimensional device simulations. The source-side diameter determines the on-current and drain-induced barrier lowering characteristics, whereas the drain-side diameter controls the band-to-band tunneling current during off-state conditions. The JNTs with short drain-side underlap lengths decrease the source/drain series resistance but increase the off-current values, especially due to large band-gap narrowing effects at the drain extension region. Proper device design of vertical GAA JNTs considering the device structure and underlap is needed to improve both on/off and short channel characteristics.

Yoon, Jun-Sik; Rim, Taiuk; Kim, Jungsik; Meyyappan, Meyya; Baek, Chang-Ki; Jeong, Yoon-Ha

2014-09-01

386

How Semiconductors and Transistors Work  

NSDL National Science Digital Library

This NSF funded site, at the University of Virginia, shows how semiconductors and transistors are constructed and work. This is a Virtual Science Lab that lets the users see how semiconductor crystals work and how they are used to make transistor switches. It is presented as a Powerpoint presentation and employs flash animation to convey many of the points.

Bean, John C.

387

The coupled atom transistor  

NASA Astrophysics Data System (ADS)

We describe the first implementation of a coupled atom transistor where two shallow donors (P or As) are implanted in a nanoscale silicon nanowire and their electronic levels are controlled with three gate voltages. Transport spectroscopy through these donors placed in series is performed both at zero and microwave frequencies. The coherence of the charge transfer between the two donors is probed by Landau–Zener–Stückelberg interferometry. Single-charge transfer at zero bias (electron pumping) has been performed and the crossover between the adiabatic and non-adiabatic regimes is studied.

Jehl, X.; Voisin, B.; Roche, B.; Dupont-Ferrier, E.; De Franceschi, S.; Sanquer, M.; Cobian, M.; Niquet, Y.-M.; Sklénard, B.; Cueto, O.; Wacquez, R.; Vinet, M.

2015-04-01

388

From transistor to nanotube  

NASA Astrophysics Data System (ADS)

We present here the main steps in the evolution of the transistor, since the tremendous invention of such a device and the introduction of the integrated circuit. We will then recall the main steps of Moore's law development. Nanotechnology began at the very beginning of the 21st century. Two aspects are presented in this article: the first, called 'More Moore', consists in continuing the laws of scale up to the physical limits; the second aspect, called 'beyond CMOS' explores new concepts such as spintronics, moletronics, nanotronics and other types of molecular electronics. To cite this article: J.-C. Boudenot, C. R. Physique 9 (2008).

Boudenot, Jean-Claude

2008-01-01

389

The coupled atom transistor.  

PubMed

We describe the first implementation of a coupled atom transistor where two shallow donors (P or As) are implanted in a nanoscale silicon nanowire and their electronic levels are controlled with three gate voltages. Transport spectroscopy through these donors placed in series is performed both at zero and microwave frequencies. The coherence of the charge transfer between the two donors is probed by Landau-Zener-Stückelberg interferometry. Single-charge transfer at zero bias (electron pumping) has been performed and the crossover between the adiabatic and non-adiabatic regimes is studied. PMID:25783566

Jehl, X; Voisin, B; Roche, B; Dupont-Ferrier, E; De Franceschi, S; Sanquer, M; Cobian, M; Niquet, Y-M; Sklénard, B; Cueto, O; Wacquez, R; Vinet, M

2015-04-22

390

Power transistor switching characterization  

NASA Technical Reports Server (NTRS)

The switching properties of power transistors are investigated. The devices studied were housed in IO-3 cases and were of an n(+)-p-n(-)-n(+) vertical dopant structure. The effects of the magnitude of the reverse-base current and temperature on the reverse-bias second breakdown characteristics are discussed. Brief discussions of device degradation due to second breakdown and of a constant voltage turn-off circuit are included. A description of a vacuum tube voltage clamp circuit which reduces clamped collector voltage overshoot is given.

Blackburn, D. L.

1981-01-01

391

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

PubMed Central

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.

Farhadi, Rozita; Farhadi, Bita

2014-01-01

392

Carbon Nanotubes as Schottky Barrier Transistors  

Microsoft Academic Search

We show that carbon nanotube transistors operate as unconventional ``Schottky barrier transistors,'' in which transistor action occurs primarily by varying the contact resistance rather than the channel conductance. Transistor characteristics are calculated for both idealized and realistic geometries, and scaling behavior is demonstrated. Our results explain a variety of experimental observations, including the quite different effects of doping and adsorbed

S. Heinze; J. Tersoff; R. Martel; V. Derycke; J. Appenzeller; Ph. Avouris

2002-01-01

393

RICE UNIVERSITY Transport in Single Molecule Transistors  

E-print Network

RICE UNIVERSITY Transport in Single Molecule Transistors by Lam H. Yu A Thesis Submitted in Partial Houston, Texas January, 2006 #12;Abstract Transport in Single Molecule Transistors by Lam H. Yu molecule transistors (SMTs), nanometer-scale transistors in which charge transport occurs through

Natelson, Douglas

394

Unsplit bipolar pulse forming line  

DOEpatents

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.

Rhodes, Mark A. (Pleasanton, CA)

2011-05-24

395

Depression and Bipolar Support Alliance  

NSDL National Science Digital Library

Living and coping with depression or bipolar disorder can be difficult, but there are a number of high-quality online resources that can be very useful to those with these conditions, or for those who work directly with these individuals. The homepage of the Depression and Bipolar Support Alliance (DBSA) can be of great help in this area, as their site includes everything from their �Real Recovery� podcasts to such basics as factsheets on both diseases. A good place to start here would be with any of the five primary sections, which include crisis intervention resources and recovery steps. Visitors can also view many of these materials in Spanish and they may also wish to sign up to receive the DBSA�s electronic newsletter.

396

Depression and Bipolar Support Alliance  

NSDL National Science Digital Library

Living and coping with depression or bipolar disorder can be difficult, but there are a number of high-quality online resources that can be very useful to those with these conditions, or for those who work directly with these individuals. The homepage of the Depression and Bipolar Support Alliance (DBSA) can be of great help in this area, as their site includes everything from their "Real Recovery" podcasts to such basics as factsheets on both diseases. A good place to start here would be with any of the five primary sections, which include crisis intervention resources and recovery steps. Visitors can also view many of these materials in Spanish and they may also wish to sign up to receive the DBSA's electronic newsletter.

397

Clinical Endophenotypes for Bipolar Disorder  

Microsoft Academic Search

\\u000a Although twin, family, and adoption studies demonstrate that bipolar disorder (BPD) is substantially heritable, the molecular\\u000a genetic basis for this illness remains elusive. Given evidence that genes predisposing to BPD may be transmitted without expression\\u000a of the clinical phenotype, interest has arisen in developing endophenotypes – indicators of processes mediating between genotype\\u000a and phenotype. Patients with BPD have subtle neuropsychological

David C. Glahn; Katherine E. Burdick

398

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

ERIC Educational Resources Information Center

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…

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

399

Impacts of crystal orientation of GaAs on the interfacial structures and electrical properties of Hf{sub 0.6}La{sub 0.4}O{sub x} films  

SciTech Connect

One of the major challenges in realizing the GaAs channel in the metal oxide semiconductor field effect transistor is the degrading in electron transport properties at the interface between GaAs and the gate oxide. In this study, Hf{sub 0.6}La{sub 0.4}O{sub x} gate oxide films were deposited at a low temperature (200?°C) on GaAs(111)A and GaAs(100) substrates by plasma enhanced atomic layer deposition. Microstructure analysis indicates that residuals of gallium oxide, arsenic oxide, and As element remained at the interface of Hf{sub 0.6}La{sub 0.4}O{sub x}/GaAs(100). On contrast, a smoother interface is observed between Hf{sub 0.6}La{sub 0.4}O{sub x} thin film and GaAs(111)A substrate. Furthermore, a reduction of interfacial layer is observed in Hf{sub 0.6}La{sub 0.4}O{sub x}/GaAs(111)A. Electrical characterization of the metal-insulator-semiconductor Pt/Hf{sub 0.6}La{sub 0.4}O{sub x}/n-GaAs(111)A capacitor indicated a reduction of D{sub it} and leakage current compared with the capacitor fabricated on GaAs(100)

Jia, Tingting; Kimura, Hideo, E-mail: kimura.hideo@nims.go.jp [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Zhao, Hongyang [Shanghai Institute of Ceramics, Chinese Academy of Sciences, Dingxi Road 1295, Shanghai 200050 (China); Yao, Qiwen; Cheng, Zhenxiang [Institute for Superconducting and Electronic Materials, University of Wollongong, Squires Way, North Wollongong, NSW 2500 (Australia); Cheng, Xinghong; Yu, Yuehui [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Micro-system and Information Technology, Chinese Academy of Sciences, Changning Road 865, Shanghai 200050 (China)

2014-04-07

400

Distinctions between bipolar and unipolar depression  

PubMed Central

This is a review of the studies comparing unipolar and bipolar depression, with focus on the course, symptomatology, neurobiology, and psychosocial literatures. These are reviewed with one question in mind: does the evidence support diagnosing bipolar and unipolar depressions as the same disorder or different? The current nomenclature of bipolar and unipolar disorders has resulted in research that compares these disorders as a whole, without considering depression separately from mania within bipolar disorder. Future research should investigate two broad categories of depression and mania as separate disease processes that are highly comorbid. PMID:15792852

Cuellar, Amy K.; Johnson, Sheri L.; Winters, Ray

2010-01-01

401

[Comparative study of recurrent and bipolar depression].  

PubMed

The purpose of the study was to determine clinical and diagnostic distinctions between the episodes of recurrent depression and bipolar depression. The subjects of the study were 79 patients meeting ICD-10 criteria for either recurrent depressive disorder or bipolar affective disorder. Patient with recurrent depression presented more prominent HDRS symptoms of depressed mood, psychomotor retardation, somatic anxiety, and gastro-intestinal somatic complains. Bipolar patients had more scores related to middle and late insomnia, agitation and suicide. In addition lower length of remission was observed in bipolar depression. The revealed differences should be taken into account in diagnostic and pharmacological treatment of various types of depression. PMID:19996503

Ismailov, F N

2009-11-01

402

Problems in the boundaries of bipolar disorders.  

PubMed

Classical concepts of bipolarity (bipolar I and bipolar II) have sometimes been extended into a broader spectrum that includes a wide variety of conditions previously diagnosed as separate forms of psychopathology. Differential diagnosis remains important, particularly in personality disorders characterized by affective instability, and in behavior disorders affecting pre-pubertal children. In the absence of biological markers or other external sources of validity, as well as lack of evidence for response to pharmacological treatment when disorders are defined more broadly, the bipolar spectrum remains an unproven hypothesis. PMID:24930522

Paris, Joel

2014-08-01

403

Crystal growth of device quality GaAs in space  

NASA Technical Reports Server (NTRS)

The optimization of space processing of GaAs is described. The detailed compositional, structural, and electronic characterization of GaAs on a macro- and microscale and the relationships between growth parameters and the properties of GaAs are among the factors discussed. The key parameters limiting device performance are assessed.

Gatos, H. C.; Lagowski, J.

1979-01-01

404

A high voltage UMOS transistor  

NASA Astrophysics Data System (ADS)

A throretical and experimental study of a novel UMOS (U for U-shaped notch) transistor structure is presented. This short channel device combines a simple U-groove geometry with features similar to those of DMOS transistors. Voltage and switching capabilities are investigated. Necessary trade-offs are emphasized in the design process and the critical fabrication steps are discussed. Both the theoretical considerations as well as the experimental results indicate that the UMOS transistor described is suitable for high voltage switching applications.

Tarasewicz, S.; Salama, C. A. T.

1981-05-01

405

A New Microwave High Power Transistor (Static Induction Transistor)  

Microsoft Academic Search

A high power transistor at microwave frequency has been realized by multi-chips of static induction transistor. An output power of 100 W at 1 GHz was obtained by good design of thermal balance and improvement of packaging. A gain of 2.2 dB and a drain efficiency of 42 % was obtained at output power of 100 W. The linear gain

Y. Kajiwara; K. Horikiri; Y. Yukimoto

1978-01-01

406

The enhancement of gate-induced-drain-leakage (GIDL) current in short-channel SOI MOSFET and its application in measuring lateral bipolar current gain ?  

Microsoft Academic Search

An off-state leakage current unique for short-channel SOI MOSFETs is reported. This off-state leakage is the amplification of gate-induced-drain-leakage current by the lateral bipolar transistor in an SOI device due to the floating body. The leakage current can be enhanced by as much as 100 times for 1\\/4 ?m SOI devices. This can pose severe constraints in future 0.1 ?m

Jian Chen; Fariborz Assaderaghi; Ping-Keung KO; Chenming Hu

1992-01-01

407

An ion-gated bipolar amplifier for ion sensing with enhanced signal and improved noise performance  

NASA Astrophysics Data System (ADS)

This work presents a proof-of-concept ion-sensitive device operating in electrolytes. The device, i.e., an ion-gated bipolar amplifier (IGBA), consists of a modified ion-sensitive field-effect transistor (ISFET) intimately integrated with a vertical bipolar junction transistor for immediate current amplification without introducing additional noise. With the current non-optimized design, the IGBA is already characterized by a 70-fold internal amplification of the ISFET output signal. This signal amplification is retained when the IGBA is used for monitoring pH variations. The tight integration significantly suppresses the interference of the IGBA signal by external noise, which leads to an improvement in signal-to-noise performance compared to its ISFET reference. The IGBA concept is especially suitable for biochips with millions of electric sensors that are connected to peripheral readout circuitry via extensive metallization which may in turn invite external interferences leading to contamination of the signal before it reaches the first external amplification stage.

Zhang, Da; Gao, Xindong; Chen, Si; Norström, Hans; Smith, Ulf; Solomon, Paul; Zhang, Shi-Li; Zhang, Zhen

2014-08-01

408

Radiation hardness measurements on components of a full custom bipolar process  

NASA Astrophysics Data System (ADS)

We present the characterization of various components of the full custom bipolar process SHPi by Tektronix with respect to radiation hardness. The motivation of this work is to design a low-power, low-noise frontend with fast shaping for silicon microstrip detectors. We have tested BJTs ( npn of various size and a lateral pnp), JFETs, Schottky diodes, implanted resistors and NiChrome resistors. The devices were irradiated to 60Co dose of up to 5 Mrad in few steps, to fluence of 5.5?10 13n cm-2 of neutrons from a spallation source in few steps and to fluence of up to 1.1?10 14cm-2 of 650 MeV protons. It allows us to characterize the sensitivity of the devices on both ionization effects and displacement damage. We have measured the radiation effects on the dc parameters and characteristics of all components as well as on noise in npn BJTs of various size considered as candidates for the preamplifier input transistor. The most significant effect which we observe is the decrease of the current gain ? in bipolar transistors for low emitter current densities. Both important noise sources, i.e. the shot noise of the collector current and the thermal noise of the base spread resistance are unaffected by irradiation.

Barberis, P.; Benotto, F.; Cartiglia, N.; Dabrowski, W.; Dorfan, D. E.; Giubellino, P.; Pitzl, D.; Rowe, W. A.; Sadrozinski, H. F.-W.; Spencer, E. N.; Turala, M.; Wilder, M.

1993-05-01

409

Optically-Activated GaAs Switches for Ground Penetrating Radar and Firing Set Applications  

SciTech Connect

Optically activated, high gain GaAs switches are being tested for many different applications. TWO such applications are ground penetrating radar (GPR) and firing set switches. The ability of high gain GaAs Photoconductive Semiconductor Switches (PCSs) to deliver fast risetime pulses makes them suitable for their use in radars that rely on fast impulses. This type of direct time domain radar is uniquely suited for the detection of buried items because it can operate at low frequency, high average power, and close to the ground, greatly increasing power on target. We have demonstrated that a PCSs based system can be used to produce a bipolar waveform with a total duration of about 6 ns and with minimal ringing. Such a pulse is radiated and returns from a 55 gallon drum will be presented. For firing sets, the switch requirements include small size, high current, dc charging, radiation hardness and modest longevity. We have switched 1 kA at 1 kV and 2.8 kA at 3 kV dc charge.

Aurand, J.; Brown, D.J.; Carin, L.; Denison, G.J.; Helgeson, W.D.; Loubriel, G.M.; Mar, A.; O'Malley, M.W.; Rinehart, L.F.; Zutavern, F.J.

1999-07-14

410

Influence of the local environment on Mn acceptors in GaAs  

NASA Astrophysics Data System (ADS)

As transistors continue to shrink toward nanoscale dimensions, their characteristics are increasingly dependent on the statistical variations of impurities in the semiconductor material. The scanning tunneling microscope (STM) can be used to not only study prototype devices with atomically precise placement of impurity atoms, but can also probe how the properties of these impurities depend on the local environment. Tunneling spectroscopy of Mn acceptors in GaAs indicates that surface-layer Mn act as a deep acceptor, with a hole binding energy that can be tuned by positioning charged defects nearby. Band bending induced by the tip or by these defects can also tune the ionization state of the acceptor complex, evident as a ring-like contrast in STM images. The interplay of these effects is explored over a wide range of defect distances, and understood using iterative simulations of tip-induced band bending.

Lee, Donghun; Gohlke, David; Benjamin, Anne; Gupta, Jay A.

2015-04-01

411

A Cryogenic GaAs PHEMT/ Ferroelectric Ku-Band Tunable Oscillator  

NASA Technical Reports Server (NTRS)

A Ku-band tunable oscillator operated at and below 77 K is described. The oscillator is based on two separate technologies: a 0.25 mm GaAs pseudomorphic high electron mobility transistor (PHEMT) circuit optimized for cryogenic operation, and a gold microstrip ring resonator patterned on a thin ferroelectric (SrTiO3) film which was laser ablated onto a LaAlO3 substrate. A tuning range of up to 3% of the center frequency was achieved by applying dc bias between the ring resonator and ground plane. To the best of our knowledge, this is the first tunable oscillator based on a thin film ferroelectric structure demonstrated in the microwave frequency range. The design methodology of the oscillator and the performance characteristics of the tunable resonator are described.

Romanofsky, Robert R.; Miranda, Felix A.; VanKeuls, Fred W.

1998-01-01

412

Influence of the local environment on Mn acceptors in GaAs.  

PubMed

As transistors continue to shrink toward nanoscale dimensions, their characteristics are increasingly dependent on the statistical variations of impurities in the semiconductor material. The scanning tunneling microscope (STM) can be used to not only study prototype devices with atomically precise placement of impurity atoms, but can also probe how the properties of these impurities depend on the local environment. Tunneling spectroscopy of Mn acceptors in GaAs indicates that surface-layer Mn act as a deep acceptor, with a hole binding energy that can be tuned by positioning charged defects nearby. Band bending induced by the tip or by these defects can also tune the ionization state of the acceptor complex, evident as a ring-like contrast in STM images. The interplay of these effects is explored over a wide range of defect distances, and understood using iterative simulations of tip-induced band bending. PMID:25782688

Lee, Donghun; Gohlke, David; Benjamin, Anne; Gupta, Jay A

2015-04-22

413

GaAs photoconductive semiconductor switch  

DOEpatents

A high gain, optically triggered, photoconductive semiconductor switch (PCSS) implemented in GaAs as a reverse-biased pin structure with a passivation layer above the intrinsic GaAs substrate in the gap between the two electrodes of the device is disclosed. The reverse-biased configuration in combination with the addition of the passivation layer greatly reduces surface current leakage that has been a problem for prior PCSS devices and enables employment of the much less expensive and more reliable DC charging systems instead of the pulsed charging systems that needed to be used with prior PCSS devices. 5 figs.

Loubriel, G.M.; Baca, A.G.; Zutavern, F.J.

1998-09-08

414

GaAs photoconductive semiconductor switch  

DOEpatents

A high gain, optically triggered, photoconductive semiconductor switch (PCSS) implemented in GaAs as a reverse-biased pin structure with a passivation layer above the intrinsic GaAs substrate in the gap between the two electrodes of the device. The reverse-biased configuration in combination with the addition of the passivation layer greatly reduces surface current leakage that has been a problem for prior PCSS devices and enables employment of the much less expensive and more reliable DC charging systems instead of the pulsed charging systems that needed to be used with prior PCSS devices.

Loubriel, Guillermo M. (Sandia Park, NM); Baca, Albert G. (Albuquerque, NM); Zutavern, Fred J. (Albuquerque, NM)

1998-01-01

415

Adiabatic Quantum Transistors  

DOE PAGESBeta

We describe a many-body quantum system that can be made to quantum compute by the adiabatic application of a large applied field to the system. Prior to the application of the field, quantum information is localized on one boundary of the device, and after the application of the field, this information propagates to the other side of the device, with a quantum circuit applied to the information. The applied circuit depends on the many-body Hamiltonian of the material, and the computation takes place in a degenerate ground space with symmetry-protected topological order. Such “adiabatic quantum transistors” are universal adiabatic quantum computing devices that have the added benefit of being modular. Here, we describe this model, provide arguments for why it is an efficient model of quantum computing, and examine these many-body systems in the presence of a noisy environment.

Bacon, Dave; Flammia, Steven T.; Crosswhite, Gregory M.

2013-06-01

416

High transconductance organic electrochemical transistors  

PubMed Central

The development of transistors with high gain is essential for applications ranging from switching elements and drivers to transducers for chemical and biological sensing. Organic transistors have become well-established based on their distinct advantages, including ease of fabrication, synthetic freedom for chemical functionalization, and the ability to take on unique form factors. These devices, however, are largely viewed as belonging to the low-end of the performance spectrum. Here we present organic electrochemical transistors with a transconductance in the mS range, outperforming transistors from both traditional and emerging semiconductors. The transconductance of these devices remains fairly constant from DC up to a frequency of the order of 1?kHz, a value determined by the process of ion transport between the electrolyte and the channel. These devices, which continue to work even after being crumpled, are predicted to be highly relevant as transducers in biosensing applications. PMID:23851620

Khodagholy, Dion; Rivnay, Jonathan; Sessolo, Michele; Gurfinkel, Moshe; Leleux, Pierre; Jimison, Leslie H.; Stavrinidou, Eleni; Herve, Thierry; Sanaur, Sébastien; Owens, Róisín M.; Malliaras, George G.

2013-01-01

417

Transistor sizing in CMOS circuits  

Microsoft Academic Search

The problem of optimally sizing transistors in a VLSI CMOS circuit is considered. Models and algorithms for performing optimization on a single path using RC-tree approximation are presented. The results of an automatic optimization procedure are discussed.

Mehmet A. Cirit

1987-01-01

418

A high performance charge plasma PN-Schottky collector transistor on silicon-on-insulator  

NASA Astrophysics Data System (ADS)

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 (?), 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 ? 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.

Loan, Sajad A.; Bashir, Faisal; Rafat, M.; Alamoud, Abdul Rehman M.; Abbasi, Shuja A.

2014-09-01

419

Bipolar Disorder in Children and Adolescents  

MedlinePLUS

... may also ask whether there is a family history of bipolar disorder or other psychiatric illnesses, such as depression or alcoholism. Doctors diagnose bipolar disorder using guidelines from the Diagnostic and Statistic Manual of Mental Disorders (DSM). To be diagnosed, the symptoms must be ...

420

Bipolar Disorder and Cognitive Therapy: A Commentary  

ERIC Educational Resources Information Center

This article comments on the three articles (Leahy, 2005; Newman, 2005; and Reilly-Harrington & Knauz, 2005) that deal with the applications of cognitive therapy to treatment of bipolar disorder. They focus on the uses of cognitive therapy in treating three important facets of the special problems of bipolar patients: rapid cycling, severe…

Riskind, John H.

2005-01-01

421

Bipolar II disorder and self-identity   

E-print Network

Background: Studies on bipolar II disorder have covered a wide scope; many report the importance of a cohesive self-concept for recovery. In spite of this, there is a dearth of research explicitly investigating how bipolar II impacts one’s self...

Hannon, Julia

2012-06-27

422

Swimming in Deep Water: Childhood Bipolar Disorder  

ERIC Educational Resources Information Center

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…

Senokossoff, Gwyn W.; Stoddard, Kim

2009-01-01

423

Bipolar Disorder in School-Age Children  

ERIC Educational Resources Information Center

This article examines the individual components of bipolar disorder in children and the behaviors that can escalate as a result of misdiagnosis and treatment. The brain/behavior relationship in bipolar disorders can be affected by genetics, developmental failure, or environmental influences, which can cause an onset of dramatic mood swings and…

Olson, Patricia M.; Pacheco, Mary Rae

2005-01-01

424

Psychosis Endophenotypes in Schizophrenia and Bipolar Disorder  

Microsoft Academic Search

Recent studies provide considerable evidence that schizo- phrenia and bipolar disorder may share overlapping etio- logic determinants. Identifying disease-related genetic effects is a major focus in schizophrenia and bipolar disor- der research, with implications for clarifying diagnosis and developing specific treatments for various impairments in these 2 disorders. Efforts have been multifaceted, with the ultimate goal of describing causal paths

Gunvant Thaker

2008-01-01

425

Family Functioning in Bipolar I Disorder  

Microsoft Academic Search

In a sample of 62 patients with Bipolar I disorder, the authors used a repeated measures longitudinal design to examine whether global family functioning was associated with the presence of a concurrent bipolar episode as well as whether global family functioning was associated with the presence of manic and depressive episodes in the following 3 months. Participants were recruited for

Lisa A. Uebelacker; Christopher G. Beevers; Cynthia L. Battle; David Strong; Gabor I. Keitner; Christine E. Ryan; David A. Solomon; Ivan W. Miller

2006-01-01

426

Subthreshold bipolarity: diagnostic issues and challenges  

PubMed Central

Background Research suggests that current diagnostic criteria for bipolar disorders may fail to include milder, but clinically significant, bipolar syndromes and that a substantial percentage of these conditions are diagnosed, by default, as unipolar major depression. Accordingly, a number of researchers have argued for the upcoming 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) to better account for subsyndromal hypomanic presentations. Methods The present paper is a critical review of research on subthreshold bipolarity, and an assessment of some of the challenges that researchers and clinicians might face if the DSM-5 were designed to systematically document subsyndromal hypomanic presentations. Results Individuals with major depressive disorder (MDD) who display subsyndromal hypomanic features, not concurrent with a major depressive episode, have a more severe course compared to individuals with MDD and no hypomanic features, and more closely resemble individuals with bipolar disorder on a number of clinical validators. Conclusion There are clinical and scientific reasons for systematically documenting subsyndromal hypomanic presentations in the assessment and diagnosis of mood disorders. However, these benefits are balanced with important challenges, including (i) the difficulty in reliably identifying subsyndromal hypomanic presentations, (ii) operationalizing subthreshold bipolarity, (iii) differentiating subthreshold bipolarity from borderline personality disorder, (iv) the risk of over-diagnosing bipolar spectrum disorders, and (v) uncertainties about optimal interventions for subthreshold bipolarity. PMID:22085472

Nusslock, Robin; Frank, Ellen

2012-01-01

427

John Bardeen and transistor physics  

NASA Astrophysics Data System (ADS)

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.

Huff, Howard R.

2001-01-01

428

Bipolar Ag-Zn battery  

NASA Technical Reports Server (NTRS)

The silver-zinc (AgZn) battery system has been unique in its ability to safely satisfy high power demand applications with low mass and volume. However, a new generation of defense, aerospace, and commercial applications will impose even higher power demands. These new power demands can be satisfied by the development of a bipolar battery design. In this configuration the power consuming, interelectrode current conductors are eliminated while the current is then conducted via the large cross-section electrode substrate. Negative and positive active materials are applied to opposite sides of a solid silver foil substrate. In addition to reducing the weight and volume required for a specified power level, the output voltage performance is also improved as follows. Reduced weight through: elimination of the plastic cell container; elimination of plate leads and intercell connector; and elimination of internal plate current collector. Increased voltage through: elimination of resistance of current collector; elimination of resistance of plate lead; and elimination of resistance of intercell connector. EPI worked previously on development of a secondary bipolar silver zinc battery. This development demonstrated the electrical capability of the system and manufacturing techniques. One difficulty with this development was mechanical problems with the seals. However, recent improvements in plastics and adhesives should eliminate the major problem of maintaining a seal around the periphery of the bipolar module. The seal problem is not as significant for a primary battery application or for a requirement for only a few discharge cycles. A second difficulty encountered was with activation (introducing electrolyte into the cell) and with venting gas from the cell without loss of electrolyte. During previous work, the following projections for energy density were made from test data for a high power system which demonstrated in excess of 50 discharge/charge cycles. Projected system power = 100 kilowatts; discharge time = 30 seconds; discharge current density = 1.75 amps/sq in.; system weight = 86 lbs (9.7 WH/lb); and system volume = 1071 cu. in. (.78 WH/cu. in.). EPI is currently working on a development program to produce a bipolar silver-zinc battery design for NASA. The potential application would be to power electromechanical actuators for space launch vehicles.

Giltner, L. John

1994-01-01

429

Electronic Model of a Ferroelectric Field Effect Transistor  

NASA Technical Reports Server (NTRS)

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.

MacLeod, Todd C.; Ho, Fat Duen; Russell, Larry (Technical Monitor)

2001-01-01

430

Evolvable circuit with transistor-level reconfigurability  

NASA Technical Reports Server (NTRS)

An evolvable circuit includes a plurality of reconfigurable switches, a plurality of transistors within a region of the circuit, the plurality of transistors having terminals, the plurality of transistors being coupled between a power source terminal and a power sink terminal so as to be capable of admitting power between the power source terminal and the power sink terminal, the plurality of transistors being coupled so that every transistor terminal to transistor terminal coupling within the region of the circuit comprises a reconfigurable switch.

Stoica, Adrian (Inventor); Salazar-Lazaro, Carlos Harold (Inventor)

2004-01-01

431

Bandwidth enhancement and optical performances of multiple quantum well transistor lasers  

E-print Network

A detailed rate-equation-based model is developed to study carrier transport effects on optical and electrical characteristics of the Multiple Quantum Well Heterojunction Bipolar Transistor Laser in time-domain. Simulation results extracted using numerical techniques in small-signal regime predict significant enhancement in device optical bandwidth when multiple quantum wells are used. Cavity length and base width are also modified to optimize the optoelectronic performances of the device. An optical bandwidth of \\approx 60GHz is achieved in the case of 5 quantum wells each of 70A widths and a cavity length of 200um.

Iman Taghavi; Hassan Kaatuzian; Jean-Pierre Leburton

2012-05-23

432

Bandwidth enhancement and optical performances of multiple quantum well transistor lasers  

E-print Network

A detailed rate-equation-based model is developed to study carrier transport effects on optical and electrical characteristics of the Multiple Quantum Well Heterojunction Bipolar Transistor Laser in time-domain. Simulation results extracted using numerical techniques in small-signal regime predict significant enhancement in device optical bandwidth when multiple quantum wells are used. Cavity length and base width are also modified to optimize the optoelectronic performances of the device. An optical bandwidth of \\approx 60GHz is achieved in the case of 5 quantum wells each of 70A widths and a cavity length of 200um.

Taghavi, Iman; Leburton, Jean-Pierre

2012-01-01

433

The prestige model of spectrum bipolarity.  

PubMed

Because affective pathogenesis is a hard problem for psychiatry, it behoves researchers to develop and test novel models of causality. We examine the notion that the adaptive drive to social investment - prestige - provides clues to the bipolar spectrum. A seven node bipolar spectrum is proposed, based on a putative gradient of "bipolarity". It is conceived that this gradient may correlate with the drive to social investment (prestige). In order to test this hypothesis with proof of concept data, a case control study categorised 228 subjects into a seven node bipolar spectrum. Whilst controlling for mood elevation and depression, differences in strategic prestige (leadership) motivation (MSPM) between spectrum groups were examined. The bipolar I (S1) node had a greater strategic prestige (leadership) motivation score than the controls (S7) by 21.17 points, 95% CI [8.16, 34.18], p<.001, d=1.05, while the bipolar II (S2) node was higher than the control group by 16.73 points, 95% CI [0.92, 32.54], p=.030, d=0.84. Whilst the pseudounipolar (S3) node (those with depression and bipolar family histories; n=17) had only a marginally statistical difference in MSPM compared to controls (p=.051), the mean difference (16.98) and d value (0.86) indicated an elevated MSPM level. Prestige (leadership) motivation score positively correlated with dimensional lifetime bipolarity (Mood Disorder Questionnaire) score (rp=0.47), supporting the spectrum prestige motivation gradient notion. Evidence is presented for a genetic disposition to elevated strategic prestige (leadership) motivation. Sensitivity to Social Inclusion (MSIS), Contingency of Self-Worth (CSW.av) and tension significantly predicted strategic prestige (leadership) motivation (MSPM) score in a multiple regression. - suggesting that a vulnerability of the social self may be a feature of bipolar disorders. The prestige model of spectrum bipolarity offers a new conceptualisation of affective disorders and has received preliminary support. PMID:25554538

Le Bas, James; Newton, Richard; Sore, Rachel; Castle, David

2015-02-01

434

GaAs Solar Cell Radiation Handbook  

NASA Technical Reports Server (NTRS)

History of GaAs solar cell development is provided. Photovoltaic equations are described along with instrumentation techniques for measuring solar cells. Radiation effects in solar cells, electrical performance, and spacecraft flight data for solar cells are discussed. The space radiation environment and solar array degradation calculations are addressed.

Anspaugh, B. E.

1996-01-01

435

Viruses, schizophrenia, and bipolar disorder.  

PubMed Central

The hypothesis that viruses or other infectious agents may cause schizophrenia or bipolar disorder dates to the 19th century but has recently been revived. It could explain many clinical, genetic, and epidemiologic aspects of these diseases, including the winter-spring birth seasonality, regional differences, urban birth, household crowding, having an older sibling, and prenatal exposure to influenza as risk factors. It could also explain observed immunological changes such as abnormalities of lymphocytes, proteins, autoantibodies, and cytokines. However, direct studies of viral infections in individuals with these psychiatric diseases have been predominantly negative. Most studies have examined antibodies in blood or cerebrospinal fluid, and relatively few studies have been done on viral antigens, genomes, cytopathic effect on cell culture, and animal transmission experiments. Viral research on schizophrenia and bipolar disorder is thus comparable to viral research on multiple sclerosis and Parkinson's disease: an attractive hypothesis with scattered interesting findings but no clear proof. The application of molecular biological techniques may allow the identification of novel infectious agents and the associations of these novel agents with serious mental diseases. PMID:7704891

Yolken, R H; Torrey, E F

1995-01-01

436

Probing Neurochemical Structure and Function of Retinal ON Bipolar Cells  

E-print Network

Probing Neurochemical Structure and Function of Retinal ON Bipolar Cells With a Transgenic Mouse Neuroanatomie, 10117 Berlin, Germany ABSTRACT Retinal ON bipolar cells make up about 70% of all bipolar cells the G-protein Go1, and closing an unidentified cation channel. To facilitate investigation of ON bipolar

Pennsylvania, University of

437

Effectiveness of Adjunctive Antidepressant Treatment for Bipolar Depression  

Microsoft Academic Search

Background Episodes of depression are the most frequent cause of disability among patients with bipolar disorder. The effectiveness and safety of standard antidepressant agents for depressive episodes associated with bipolar disorder (bipolar depression) have not been well studied. Our study was designed to determine whether adjunctive antide- pressant therapy reduces symptoms of bipolar depression without increasing the risk of mania.

Gary S. Sachs; Andrew A. Nierenberg; Joseph R. Calabrese; Lauren B. Marangell; Stephen R. Wisniewski; Laszlo Gyulai; Edward S. Friedman; Charles L. Bowden; Mark D. Fossey; Michael J. Ostacher; Terence A. Ketter; Jayendra Patel; Peter Hauser; Daniel Rapport; James M. Martinez; Michael H. Allen; David J. Miklowitz; Michael W. Otto; Ellen B. Dennehy; Michael E. Thase

2007-01-01

438

Major Depressive Disorder with Anger: A Bipolar Spectrum Disorder?  

Microsoft Academic Search

Background: Depression with anger may be more common in bipolar disorders. The aim of the study was to assess whether major depressive disorder (MDD) with anger could be included in the bipolar spectrum, by comparing it to MDD without anger and to bipolar II disorder. Methods: Consecutive outpatients (281 bipolar II disorder and 202 MDD) presenting for major depressive episode

Franco Benazzi

2003-01-01

439

Subnanosecond photoconductive switching in GaAs  

SciTech Connect

We are conducting research in photoconductive switching for the purpose of generating microwave pulses with amplitudes up to 50 kV. This technology has direct application to impulse radar and HPM sources. We are exploiting the very fast recombination rates of Gallium Arsenide (GaAs) to explore the potential of GaAs as an on-off switch when operating in the linear mode (the linear mode is defined such that one carrier pair is generated for each photon absorbed). In addition, we are exploring the potential GaAs to act as a closing switch in avalanche'' mode at high fields. We have observed switch closing times of less than 200 psec with a 100 psec duration laser pulse and opening times of less than 400 psec with neutron irradiated GaAs at fields of tens of kV/cm. If the field is increased and the laser energy decreased, the laser can be used to trigger photoconductive switches into avalanche'' mode of operation in which carrier multiplication occurs. This mode of operation is quite promising since the switches close in less than 1 nsec while realizing significant energy gain (ratio of electrical energy in the pulse to optical trigger energy). We are currently investigating both large area (1 sq cm) and small area (< 1 sq mm) switches illuminated by GaAlAs laser diodes at 900 nm and Nd:YAG lasers at 1.06 micrometers. Preliminary results indicate that the closing time of the avalanche switches depends primarily on the material properties of the devices with closing times of 300--1300 psec at voltages of 6--35 kV. We will present experimental results for linear, lock on and avalanche mode operation of GaAs photoconductive switches and how these pulses may be applied to microwave generation. 3 refs.

Druce, R.L.; Pocha, M.D.; Griffin, K.L.

1991-04-01

440

Subnanosecond photoconductive switching in GaAs  

SciTech Connect

We are conducting research in photoconductive switching for the purpose of generating microwave pulses with amplitudes up to 50 kV. This technology has direct application to impulse radar and HPM sources. We are exploiting the very fast recombination rates of Gallium Arsenide (GaAs) to explore the potential of GaAs as an on-off switch when operating in the linear mode (the linear mode is defined such that one carrier pair is generated for each photon absorbed). In addition, we are exploring the potential of GaAs to act as a closing switch in avalanche'' mode at high fields. We have observed switch closing times of less than 200 psec with 100 psec duration laser pulse and opening times of less than 400 psec with neutron irradiated GaAs at fields of tens of kV/cm. If the field is increased and the laser energy decreased, the laser can be used to trigger photoconductive switches into an avalanche'' mode of operation in which carrier multiplication occurs. This mode of operation is quite promising since the switches close in less than 1 nsec while realizing significant energy gain (ratio of electrical energy in the pulse to optical trigger energy). We are currently investigating both large are (1 sq cm) and small area (<1 sq mm) switches illuminated by GaAlAs laser diodes at 900 nm and Nd:YAG lasers at 1.06 micrometers. Preliminary results indicate that the closing time of the avalanche switches depends primarily on the material properties of the devices with closing times of 300--1300 psec at voltages of 6-35 kV. We will present experimental results for linear, lock on and avalanche mode operation of GaAs photoconductive switches and how these pulses may be applied to microwave generation. 3 refs., 11 figs.

Druce, R.L.; Pocha, M.D.; Griffin, K.L.

1990-01-01

441

Subnanosecond photoconductive switching in GaAs  

SciTech Connect

We are conducting research in photoconductive switching for the purpose of generating microwave pulses with amplitudes up to 50 kV. This technology has direct application to impulse radar and HPM sources. We are exploiting the very fast recombination rates of Gallium Arsenide (GaAs) to explore the potential of GaAs as an on-off switch when operating in the linear mode (the linear mode is defined such that one carrier pair is generated for each photon absorbed). In addition, we are exploring the potential GaAs to act as a closing switch in ``avalanche`` mode at high fields. We have observed switch closing times of less than 200 psec with a 100 psec duration laser pulse and opening times of less than 400 psec with neutron irradiated GaAs at fields of tens of kV/cm. If the field is increased and the laser energy decreased, the laser can be used to trigger photoconductive switches into ``avalanche`` mode of operation in which carrier multiplication occurs. This mode of operation is quite promising since the switches close in less than 1 nsec while realizing significant energy gain (ratio of electrical energy in the pulse to optical trigger energy). We are currently investigating both large area (1 sq cm) and small area (< 1 sq mm) switches illuminated by GaAlAs laser diodes at 900 nm and Nd:YAG lasers at 1.06 micrometers. Preliminary results indicate that the closing time of the avalanche switches depends primarily on the material properties of the devices with closing times of 300--1300 psec at voltages of 6--35 kV. We will present experimental results for linear, lock on and avalanche mode operation of GaAs photoconductive switches and how these pulses may be applied to microwave generation. 3 refs.

Druce, R.L.; Pocha, M.D.; Griffin, K.L.

1991-04-01

442

Electrical detection of the biological interaction of a charged peptide via gallium arsenide junction-field-effect transistors  

NASA Astrophysics Data System (ADS)

GaAs junction-field-effect transistors (JFETs) are utilized to achieve label-free detection of biological interaction between a probe transactivating transcriptional activator (TAT) peptide and the target trans-activation-responsive (TAR) RNA. The TAT peptide is a short sequence derived from the human immunodeficiency virus-type 1 TAT protein. The GaAs JFETs are modified with a mixed adlayer of 1-octadecanethiol (ODT) and TAT peptide, with the ODT passivating the GaAs surface from polar ions in physiological solutions and the TAT peptide providing selective binding sites for TAR RNA. The devices modified with the mixed adlayer exhibit a negative pinch-off voltage (VP) shift, which is attributed to the fixed positive charges from the arginine-rich regions in the TAT peptide. Immersing the modified devices into a TAR RNA solution results in a large positive VP shift (>1 V) and a steeper subthreshold slope (˜80 mV/decade), whereas "dummy" RNA induced a small positive VP shift (˜0.3 V) without a significant change in subthreshold slopes (˜330 mV/decade). The observed modulation of device characteristics is analyzed with analytical modeling and two-dimensional numerical device simulations to investigate the electronic interactions between the GaAs JFETs and biological molecules.

Lee, Kangho; Nair, Pradeep R.; Alam, Muhammad A.; Janes, David B.; Wampler, Heeyeon P.; Zemlyanov, Dmitry Y.; Ivanisevic, Albena

2008-06-01

443

Harnessing denatured protein for controllable bipolar doping of a monolayer graphene.  

PubMed

In this work, we demonstrated tunable p- and/or n-type doping of chemical vapor deposition-grown graphene with the use of protein bovine serum albumin (BSA) as a dopant. BSA undergoes protonation or deprotonation reaction subject to solution pH, thereby acting as either an electron donor or an electron acceptor on the graphene surface layered with denatured BSA through ?-stacking interaction. This direct annealing of graphene with denatured BSA of amphoteric nature rendered facilitated fabrication of a p- and/or n-type graphene transistor by modulating pH-dependent net charges of the single dopant. Following AFM confirmation of the BSA/graphene interface assembly, the carrier transport properties of BSA-doped graphene transistors were assessed by I-V measurement and Raman spectra to show effective charge modulation of the graphene enabled by BSA doping at various pH conditions. The protein-mediated bipolar doping of graphene demonstrated in our work is simple, scalable, and straightforward; the proposed scheme is therefore expected to provide a useful alternative for fabricating graphene transistors of novel properties and promote their implementation in practice. PMID:25546483

Jang, Sung Kyu; Jang, Ji-Ryang; Choe, Woo-Seok; Lee, Sungjoo

2015-01-21

444

Bipolar Janus particle assembly in microdevice.  

PubMed

In recent years, there are significant interests in the manipulation of bipolar Janus particles. In this article, we investigate the transient behavior of the electro-orientation process and particle-particle interaction of ellipsoidal bipolar Janus particles in the presence and absence of a DC electric field. The bipolar particle dynamics is modeled with a body force term in the fluid flow equations based on the Maxwell stress tensor. This force is due to presence of bipolar surface charges on the particles as well as their interactions with an imposed field. An interface resolved numerical scheme that consider the finite size of the particle is adopted for computation of the electric and flow fields. Our numerical results show that in the absence of an electric field, particles can undergo self-orientation to reach an equilibrium position. The time taken to reach a stable orientation depends on the initial configuration and inter-particle separation distance. Bipolar particles experience forces only on their polar ends, a phenomena that is difficult to capture with noninterface resolved methods. When bipolar particles are exposed to an external electric field, they rotate to align along the external electric field direction. Depending upon the initial configuration, particles orient via clockwise or counter clockwise rotations to form head to tail chains. The time required to form particle assembly strongly depends on particle size and bipolar charge density. The present numerical algorithm can be applied to a wider class of dual-faced Janus particles. PMID:25475510

Hossan, Mohammad R; Gopmandal, Partha P; Dillon, Robert; Dutta, Prashanta

2015-03-01

445

Brief Report: A Family Risk Study Exploring Bipolar Spectrum Problems and Cognitive Biases in Adolescent Children of Bipolar Parents  

ERIC Educational Resources Information Center

Children of parents with bipolar disorder are at increased risk of bipolar spectrum diagnoses. This cross-sectional study explores cognitive factors in the prediction of vulnerability to bipolar disorder. Adolescents at high-risk (with a parent with bipolar disorder; n = 23) and age and gender matched adolescents (n = 24) were recruited. Parent…

Espie, Jonathan; Jones, Steven H.; Vance, Yvonne H.; Tai, Sara J.

2012-01-01

446

Content The classic outranking concept Outranking with bipolar veto Conclusion On a bipolar foundation of the outranking  

E-print Network

Content The classic outranking concept Outranking with bipolar veto Conclusion On a bipolar April 2010 1 / 17 Content The classic outranking concept Outranking with bipolar veto Conclusion Outranking with bipolar veto Conclusion Notations · A = {x, y, z, ...} is a finite set of decision

Bisdorff, Raymond

447

Transistorized! The History of the Invention of the Transistor  

NSDL National Science Digital Library

Hosted by the Public Broadcasting Service (PBS) in collaboration with the American Institute of Physics and ScienCentral, Inc., this handsome Website serves as a companion to an upcoming PBS documentary, Transistorized!, to be aired November 8, 1999. The searchable site offers in-depth background to the history and science of transistors. An Interactives section includes a rubic's cube type of puzzle using elements from the Periodic Table, and a game which allows players to form their own semiconductor crystals. A hyper-linked glossary, a resources section with links to Websites, and a print bibliography round out this well-produced site.

American Institute of Physics.

448

Electroluminescence from a Single-Nanocrystal Transistor  

E-print Network

Electroluminescence from a Single-Nanocrystal Transistor Mark S. Gudiksen, Kristin N. Maher, Lian September 8, 2005 ABSTRACT We report the fabrication and characterization of light-emitting transistors- emitting transistors incorporating individual CdSe nano- crystals. Unlike the two-terminal devices employed

Heller, Eric

449

DECISION DIAGRAMS AND PASS TRANSISTOR LOGIC SYNTHESIS  

E-print Network

DECISION DIAGRAMS AND PASS TRANSISTOR LOGIC SYNTHESIS V. Bertacco S. Minato P. Verplaetse L. Benini by ARPA, under grant No. DABT63-95-C-0049. #12;Decision Diagrams and Pass Transistor Logic Synthesis V transistors and domino logic. The synthesis of these cells is based on BDD and ZBDD representations

De Micheli, Giovanni

450

Single Carbon Nanotube Transistor at GHz Frequency  

E-print Network

Single Carbon Nanotube Transistor at GHz Frequency J. Chaste,, L. Lechner,£ P. Morfin,, G. Fe operation of top-gated single carbon nanotube transistors. From transmission measurements in the 0.1-1.6 GHz effect transistors (CNT-FETs) are very attractive as ultimate, quantum limited devices. In particular

Plaçais, Bernard

451

High Performance Silicon Nanowire Field Effect Transistors  

Microsoft Academic Search

Silicon nanowires can be prepared with single-crystal structures, diameters as small as several nanometers and controllable hole and electron doping, and thus represent powerful building blocks for nanoelectronics devices such as field effect transistors. To explore the potential limits of silicon nanowire transistors, we have examined the influence of source-drain contact thermal annealing and surface passivation on key transistor properties.

Yi Cui; Zhaohui Zhong; Deli Wang; Wayne U. Wang; Charles M. Lieber

2003-01-01

452

Integration of Cell Membranes and Nanotube Transistors  

E-print Network

Integration of Cell Membranes and Nanotube Transistors Keith Bradley, Alona Davis, Jean. As the nanoelectronic device, we use a nanotube network transistor, which incorporates many individual nanotubes as transistors, and that the two systems interact. Further, we use the interaction to study the charge

Gruner, George

453

Electronics MOS Field-Effect Transistors  

E-print Network

ECEN 325 Electronics MOS Field-Effect Transistors Dr. Aydin Ilker Kar¸silayan Texas A&M University. Kar¸silayan - MOS Field-Effect Transistors 1 #12;CMOS Physical StructureCMOS Physical Structure Cross 325 Electronics - Aydin I. Kar¸silayan - MOS Field-Effect Transistors 2 #12;TAMU-ELEN-325 J. Silva

Palermo, Sam

454

Antidepressant chronotherapeutics for bipolar depression  

PubMed Central

Chronotherapeutics refers to treatments based on the principles of circadian rhythm organization and sleep physiology, which control the exposure to environmental stimuli that act on biological rhythms, in order to achieve therapeutic effects in the treatment of psychiatric conditions. It includes manipulations of the sleep-wake cycle such as sleep deprivation and sleep phase advance, and controlled exposure to light and dark. The antidepressant effects of chronotherapeutics are evident in difficult-to-treat conditions such as bipolar depression, which has been associated with extremely low success rates of antidepressant drugs in naturalistic settings and with stable antidepressant response to chronotherapeutics in more than half of the patients. Recent advances in the study of the effects of chronotherapeutics on neurotransmitter systems, and on the biological clock machinery, allow us to pinpoint its mechanism of action and to transform it from a neglected or “orphan” treatment to a powerful clinical instrument in everyday psychiatric practice. PMID:23393416

Benedetti, Francesco

2012-01-01

455

Composite substrate for bipolar electrodes  

DOEpatents

Substrates for electrode systems, particularly those to be used for bipolar electrodes in zinc-bromine batteries, are disclosed. The substrates preferably include carbon-black as a conductive filler in a polymeric matrix, with reinforcing materials such as glass fibers. Warpage of the zinc-bromine electrodes which was experienced in the prior art and which was believed to be caused by physical expansion of the electrodes due to bromine absorption by the carbon-black, is substantially eliminated when new substrate fabrication techniques are employed. In the present invention, substrates are prepared using a lamination process known as glass mat reinforced thermoplastics technology or, in an alternate embodiment, the substrate is made using a slurry process. 4 figs.

Tekkanat, B.; Bolstad, J.J.

1992-12-22

456

Composite substrate for bipolar electrodes  

DOEpatents

Substrates for electrode systems, particularly those to be used for bipolar electrodes in zinc-bromine batteries, are disclosed. The substrates preferably include carbon-black as a conductive filler in a polymeric matrix, with reinforcing materials such as glass fibers. Warpage of the zinc-bromine electrodes which was experienced in the prior art and which was believed to be caused by physical expansion of the electrodes due to bromine absorption by the carbon-black, is substantially eliminated when new substrate fabrication techniques are employed. In the pesent invention, substrates are prepared using a lamination process known as glass mat reinforced thermoplastics technology or, in an alternate embodiment, the substrate is made using a slurry process.

Tekkanat, Bora (Milwaukee, WI); Bolstad, James J. (Shorewood, WI)

1992-12-22

457

Comorbidity in Pediatric Bipolar Disorder  

PubMed Central

Synopsis A growing literature shows the pervasiveness and importance of comorbidity in youth with bipolar disorder (BPD). For instance, up to 90% of youth with BPD have been described to manifest comorbidity with attention deficit hyperactivity disorder. Multiple anxiety, substance use, and disruptive behavior disorders are the other most commonly reported comorbidities with BPD. Moreover, important recent data highlights the importance of obsessive compulsive and pervasive developmental illness in the context of BPD. Data suggests that not only special developmental relationships are operant in context to comorbidity, but also that the presence of comorbid disorders with BPD results in a more severe clinical condition. Moreover, the presence of comorbidity has therapeutic implications for the treatment response for both BPD and the associated comorbid disorder. Future longitudinal studies to address the relationship and the impact of comorbid disorders on course and therapeutic response over time are required in youth with BPD. PMID:19264265

Joshi, Gagan; Wilens, Timothy

2013-01-01

458

Miniature Bipolar Electrostatic Ion Thruster  

NASA Technical Reports Server (NTRS)

The figure presents a concept of a bipolar miniature electrostatic ion thruster for maneuvering a small spacecraft. The ionization device in the proposed thruster would be a 0.1-micron-thick dielectric membrane with metal electrodes on both sides. Small conical holes would be micromachined through the membrane and electrodes. An electric potential of the order of a volt applied between the membrane electrodes would give rise to an electric field of the order of several mega-volts per meter in the submicron gap between the electrodes. An electric field of this magnitude would be sufficient to ionize all the molecules that enter the holes. In a thruster-based on this concept, one or more propellant gases would be introduced into such a membrane ionizer. Unlike in larger prior ion thrusters, all of the propellant molecules would be ionized. This thruster would be capable of bipolar operation. There would be two accelerator grids - one located forward and one located aft of the membrane ionizer. In one mode of operation, which one could denote the forward mode, positive ions leaving the ionizer on the backside would be accelerated to high momentum by an electric field between the ionizer and an accelerator grid. Electrons leaving the ionizer on the front side would be ejected into free space by a smaller accelerating field. The equality of the ion and electron currents would eliminate the need for an additional electron- or ion-emitting device to keep the spacecraft charge-neutral. In another mode of operation, which could denote the reverse mode, the polarities of the voltages applied to the accelerator grids and to the electrodes of the membrane ionizer would be the reverse of those of the forward mode. The reversal of electric fields would cause the ion and electrons to be ejected in the reverse of their forward mode directions, thereby giving rise to thrust in the direction opposite that of the forward mode.

Hartley, Frank T.

2006-01-01

459

LEC GaAs for integrated circuit applications  

NASA Technical Reports Server (NTRS)

Recent developments in liquid encapsulated Czochralski techniques for the growth of semiinsulating GaAs for integrated circuit applications have resulted in significant improvements in the quality and quantity of GaAs material suitable for device processing. The emergence of high performance GaAs integrated circuit technologies has accelerated the demand for high quality, large diameter semiinsulating GaAs substrates. The new device technologies, including digital integrated circuits, monolithic microwave integrated circuits and charge coupled devices have largely adopted direct ion implantation for the formation of doped layers. Ion implantation lends itself to good uniformity and reproducibility, high yield and low cost; however, this technique also places stringent demands on the quality of the semiinsulating GaAs substrates. Although significant progress was made in developing a viable planar ion implantation technology, the variability and poor quality of GaAs substrates have hindered progress in process development.

Kirkpatrick, C. G.; Chen, R. T.; Homes, D. E.; Asbeck, P. M.; Elliott, K. R.; Fairman, R. D.; Oliver, J. D.

1984-01-01

460

Investigation of double-delta-doped InAlGaP\\/GaAs\\/InGaAs field effect transistors  

Microsoft Academic Search

The double-delta-doped In0.5(Al0.7Ga0.3)0.5P\\/GaAs\\/In0.3Ga0.7As field-effect transistors (FETs) epitaxial layers were grown on (100)-oriented semi-insulating GaAs substrate using low-pressure metalorganic chemical vapor deposition system. To study the characteristics of the FETs with and without illuminating of laser beams of various wavelengths, we find that both IDS–VDS characteristics and gm–VGS characteristics have not been affected by the excitation for the laser beam of

Hsin-Ying Lee; Iang-Jeng Lin; Hir-Ming Shieh; Ching-Ting Lee

2002-01-01

461

Empirical typology of bipolar I mood episodes*  

PubMed Central

Background Much remains unknown about the phenomenology of bipolar I disorder. Aims To determine the type of bipolar I mood episodes that occur over time, and their relative frequency. Method A total of 219 individuals with Research Diagnostic Criteria bipolar I disorder were prospectively followed for up to 25 years (median 20 years). Psychopathology was assessed with the Longitudinal Interval Follow-up Evaluation. Results Overall, 1208 mood episodes were prospectively observed. The episodes were empirically classified as follows: major depression, 30.9% (n = 373); minor depression, 13.0% (n = 157); mania, 20.4% (n = 246); hypomania, 10.4% (n = 126); cycling, 17.3% (n = 210); cycling plus mixed state, 7.8% (n = 94); and mixed, 0.2% (n = 2). Conclusions Cycling episodes constituted 25% of all episodes. Work groups revising ICD–10 and DSM–IV should add a category for bipolar I cycling episode. PMID:19949203

Solomon, David A.; Leon, Andrew C.; Endicott, Jean; Coryell, William H.; Li, Chunshan; Fiedorowicz, Jess G.; Keller, Martin B.

2009-01-01

462

Hippocampal function in schizophrenia and bipolar disorder   

E-print Network

Background. The hippocampus plays a central role in memory formation. There is considerable evidence of abnormalities in hippocampal structure and function in schizophrenia, which may differentiate it from bipolar disorder. However, no previous...

Hall, J.; Whalley, H. C.; Marwick, K.; McKirdy, J.; Sussmann, J.; Romaniuk, L.; Johnstone, E. C.; Wan, H. I.; McIntosh, A. M.; Lawrie, S. M.

463

GaAs transferred electron devices and field effect transistors in monolithic integrated circuits  

Microsoft Academic Search

Analog-to-digital conversion is being extended to data rates of up to a few giga-samples per second, by advancements in materials, device and process technology. Specific improvements in the material are the result of improved substrate qualification procedures. The primary process improvements include improved annealing and capping for repeatability in ion implantation and selective implantation for reduced contact resistance in ohmic

T. G. Mills

1979-01-01

464

Silicon on insulator self-aligned transistors  

DOEpatents

A method for fabricating thin-film single-crystal silicon-on-insulator (SOI) self-aligned transistors. Standard processing of silicon substrates is used to fabricate the transistors. Physical spaces, between the source and gate, and the drain and gate, introduced by etching the polysilicon gate material, are used to provide connecting implants (bridges) which allow the transistor to perform normally. After completion of the silicon substrate processing, the silicon wafer is bonded to an insulator (glass) substrate, and the silicon substrate is removed leaving the transistors on the insulator (glass) substrate. Transistors fabricated by this method may be utilized, for example, in flat panel displays, etc.

McCarthy, Anthony M.

2003-11-18

465

Crystal growth of device quality GaAs in space  

NASA Technical Reports Server (NTRS)

The crystal growth, device processing and device related properties and phenomena of GaAs are investigated. Our GaAs research evolves about these key thrust areas. The overall program combines: (1) studies of crystal growth on novel approaches to engineering of semiconductor materials (i.e., GaAs and related compounds); (2) investigation and correlation of materials properties and electronic characteristics on a macro- and microscale; (3) investigation of electronic properties and phenomena controlling device applications and device performance. The ground based program is developed which would insure successful experimentation with and eventually processing of GaAs in a near zero gravity environment.

Gatos, H. C.; Lagowski, J.

1984-01-01

466

GaAs detectors for medical imaging  

Microsoft Academic Search

X-ray detectors for use with a scanning radiographic device have been developed based on the technique of compensated semi-insulating GaAs. The main detector feature is a linear current-voltage characteristic due to the use of Ohmic contacts. The detector consists of two identical detectors connected to power supplies with different polarities in order to minimize the detector leakage current. Testing of

G. I. Ayzenshtat; E. A. Babichev; S. E. Baru; V. R. Groshev; G. A. Savinov; O. P. Tolbanov; A. P. Vorobiev

2003-01-01

467

GaAs detectors for medical imaging  

Microsoft Academic Search

X-ray detectors for use with a scanning radiographic device have been developed based on the technique of compensated semi-insulating GaAs. The main detector feature is a linear current–voltage characteristic due to the use of Ohmic contacts. The detector consists of two identical detectors connected to power supplies with different polarities in order to minimize the detector leakage current.Testing of the

G. I. Ayzenshtat; E. A. Babichev; S. E. Baru; V. R. Groshev; G. A. Savinov; O. P. Tolbanov; A. P. Vorobiev

2003-01-01

468

Pulsed GaAs laser terrain profiler.  

PubMed

A pulsed GaAs laser terrain profiler has been successfully tested and flown. Preliminary flight data indicate excellent resolution, with terrain features easily identifiable. Unique design features and typical flight results are given. The laser profiler is to be used as part of an airborne surveying package which will contain an inertial measurement unit and laser tracker to provide three-coordinate position information as well as base motion isolation and stabilization control for the profiler. PMID:20197890

Mamon, G; Youmans, D G; Sztankay, Z G; Mongan, C E

1978-03-15

469

Femoral stem dislodgement during bipolar hemiarthroplasty dislocation.  

PubMed

Bipolar hemiarthroplasty remains a treatment option for displaced femoral neck fractures in elderly patients without pre-existing hip disease. Implant-related complications associated with this procedure include acetabular erosion, dislocation, disassembly of the modular components, polyethylene debris-induced osteolysis, metallosis from outer cup impingement, and femoral component loosening. This article presents a case of a patient in whom the polished collarless tapered femoral stem dislodged out of the cement mantle during traumatic bipolar hemiarthroplasty dislocation, 28 days after the index procedure. This complication, associated with bipolar hemiarthroplasty dislocation, was adequately managed by driving the stem back to the original cement mantle, followed by reduction of bipolar component dislocation and placing bone cement over the shoulder of the femoral stem to prevent a new dislodgement episode. Although rare, dislodgement of cemented polished collarless tapered stems from the cement mantle has been recently reported either during dislocation or, more frequently, as a complication of reduction of a dislocated total hip arthroplasty. However, its occurrence in association with bipolar hemiarthroplasty dislocation was not found to have been reported in the literature. The occurrence of femoral stem dislodgement during bipolar hemiarthroplasty dislocation should be considered as a possible complication of such a procedure and may be prevented by routinely placing bone cement over the shoulder of the femoral implant. PMID:21667909

Marcelino Gomes, Luiz S; do Carmo, Wellington; de Souza, Wender

2011-06-01

470

Rumination in bipolar disorder: evidence for an unquiet mind  

PubMed Central

Depression in bipolar disorder has long been thought to be a state characterized by mental inactivity. However, recent research demonstrates that patients with bipolar disorder engage in rumination, a form of self-focused repetitive cognitive activity, in depressed as well as in manic states. While rumination has long been associated with depressed states in major depressive disorder, the finding that patients with bipolar disorder ruminate in manic states is unique to bipolar disorder and challenges explanations put forward for why people ruminate. We review the research on rumination in bipolar disorder and propose that rumination in bipolar disorder, in both manic and depressed states, reflects executive dysfunction. We also review the neurobiology of bipolar disorder and recent neuroimaging studies of rumination, which is consistent with our hypothesis that the tendency to ruminate reflects executive dysfunction in bipolar disorder. Finally, we relate the neurobiology of rumination to the neurobiology of emotion regulation, which is disrupted in bipolar disorder. PMID:22738363

2012-01-01

471

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

NASA Astrophysics Data System (ADS)

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.

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

2004-07-01

472

GaAs Molecular Beam Epitaxy on Be Implanted GaAs Layers  

NASA Astrophysics Data System (ADS)

GaAs layers have been grown by molecular beam epitaxy (MBE) on Be implanted GaAs layers using maskless ion implantation. Low-temperature (4.2 K) photoluminescence (PL) of the Be implanted layers and successively grown MBE layers on the implanted layer without post-anneal of implanted damages, has been measured. PL intensity of bound exiton from the implanted layers with dose of 1× 1012{-}1× 1013 ions cm-2 at 160 keV decreased considerably compared with the unimplanted layers. However, PL intensity measurement has shown that a high quality GaAs could be grown on top of the implanted layer by MBE at 600°C without post-implantation anneal.

Takamori, Akira; Miyauchi, Eizo; Arimoto, Hiroshi; Bamba, Yasuo; Hashimoto, Hisao

1983-08-01

473

Growth and defects of GaAs and InGaAs films on porous GaAs substrates  

Microsoft Academic Search

We investigated the opportunities to increase the electric uniformity of GaAs and InGaAs films grown by molecular-beam epitaxy (MBE) technique on monocrystalline (single crystal) GaAs: both on porous and conventional so-called “monolithic” (without pores) GaAs (100) substrates. The basic attention was given to study the electrically active defects in films by using scanning electron microscope (SEM) with new technique which

Alexander N. Buzynin; Yury N. Buzynin; Alexander V. Belyaev; Albert E. Luk'yanov; Eduard I. Rau

2007-01-01

474

Temporal order of bipolar cell genesis in the neural retina  

PubMed Central

Background Retinal bipolar cells comprise a diverse group of neurons. Cone bipolar cells and rod bipolar cells are so named for their connections with cone and rod photoreceptors, respectively. Morphological criteria have been established that distinguish nine types of cone bipolar cells and one type of rod bipolar cell in mouse and rat. While anatomical and physiological aspects of bipolar types have been actively studied, little is known about the sequence of events that leads to bipolar cell type specification and the potential relationship this process may have with synapse formation in the outer plexiform layer. In this study, we have examined the birth order of rod and cone bipolar cells in the developing mouse and rat in vivo. Results Using retroviral lineage analysis with the histochemical marker alkaline phosphatase, the percentage of cone and rod bipolar cells born on postnatal day 0 (P0), P4, and P6 were determined, based upon the well characterized morphology of these cells in the adult rat retina. In this in vivo experiment, we have demonstrated that cone bipolar genesis clearly precedes rod bipolar genesis. In addition, in the postnatal mouse retina, using a combination of tritiated-thymidine birthdating and immunohistochemistry to distinguish bipolar types, we have similarly found that cone bipolar genesis precedes rod bipolar genesis. The tritiated-thymidine birthdating studies also included quantification of the birth of all postnatally generated retinal cell types in the mouse. Conclusion Using two independent in vivo methodologies in rat and mouse retina, we have demonstrated that there are distinct waves of genesis of the two major bipolar cell types, with cone bipolar genesis preceding rod bipolar genesis. These waves of bipolar genesis correspond to the order of genesis of the presynaptic photoreceptor cell types. PMID:18215319

Morrow, Eric M; Chen, C-M Amy; Cepko, Constance L

2008-01-01

475

Power static induction transistor technology  

Microsoft Academic Search

Static induction transistor (SIT) is characterized by short channel structure and the relatively low impurity concentration in the channel, so that the potential profile near the source region is effectively controlled by the drain voltage as well as the gate voltage. Majority carriers in the source region are directly injected into the channel and their amount continuously increases with increasing

T. Ohmi

1979-01-01

476

Reigniting innovation in the transistor  

Microsoft Academic Search

Today the transistor is integral to the electronic circuitry that wires our lives. When Bardeen and Brattain first observed an amplified signal by connecting electrodes to a germanium crystal they saw that their 'semiconductor triode' could prove a useful alternative to the more cumbersome vacuum tubes used at the time [1]. But it was perhaps William Schottky who recognized the

Anna Demming

2012-01-01

477

Matching properties of MOS transistors  

Microsoft Academic Search

The matching properties of the threshold voltage, substrate factor, aud current factor of MOS transistors have been analyzed and measrrred. Improvements to the existing theory are giveu, as well as extensions for Iong-dktance matching and rotation of devices. Matching parameters of several processes are compared. The matching results have been verified by measurements and calculations on several basic circuits.

MARCEL J. M. PELGROM; AAD C. J. DUINMAIJER; P. G. WELBERS

1989-01-01

478

The four-gate transistor  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

479

Recent Progress with Vertical Transistors  

Microsoft Academic Search

Vertical MOS transistors are a promising approach for channel lengths in the range of 100 to 25nm without the need for extreme fine line lithography. These devices provide high satura­ tion currents due to the short channel length and small lateral size due to the 3D-geometry. The channel is defined by epitaxy which can be grown with very good layer

Lothar Risch; Thomas Aeugle; Wolfgang Rosner

1997-01-01

480

Bipolar patients with seasonal pattern 1 BIPOLAR DISORDER WITH SEASONAL PATTERN  

E-print Network

Bipolar patients with seasonal pattern 1 BIPOLAR DISORDER WITH SEASONAL PATTERN: CLINICAL) Fondation FondaMental, Créteil, 94000, France. 6) AP-HP, GH Saint-Louis - Lariboisière - Fernand Widal, Pôle Disorders Program, Clinical Institute of Neuroscience, Hospital Clinic, Institut d

Boyer, Edmond

481

Clinical, Demographic, and Familial Correlates of Bipolar Spectrum Disorders among Offspring of Parents with Bipolar Disorder  

ERIC Educational Resources Information Center

Objective: Despite increased risk, most offspring of parents with bipolar disorder (BP) do not manifest BP. The identification of risk factors for BP among offspring could improve preventive and treatment strategies. We examined this topic in the Pittsburgh Bipolar Offspring Study (BIOS). Method: Subjects included 388 offspring, ages 7-17 years,…

Goldstein, Benjamin I.; Shamseddeen, Wael; Axelson, David A.; Kalas, Cathy; Monk, Kelly; Brent, David A.; Kupfer, David J.; Birmaher, Boris

2010-01-01

482

Subcortical Gray Matter Volume Abnormalities in Healthy Bipolar Offspring: Potential Neuroanatomical Risk Marker for Bipolar Disorder?  

ERIC Educational Resources Information Center

A study is conducted to examine the extent to which bipolar disorder (BD) is associated with gray matter volume abnormalities in brain regions in healthy bipolar offspring relative to age-matched controls. Results show increased gray matter volume in the parahippocampus/hippocampus in healthy offspring at genetic risk for BD.

Ladouceur, Cecile D.; Almeida, Jorge R. C.; Birmaher, Boris; Axelson, David A.; Nau, Sharon; Kalas, Catherine; Monk, Kelly; Kupfer, David J.; Phillips, Mary L.

2008-01-01

483

Kleine-Levin syndrome and bipolar disorder Kleine-Levin syndrome and bipolar disorder  

E-print Network

disorder ABSTRACT Objectives: Kleine-Levin syndrome (KLS) is a rare sleep disorder (1­2 cases per million-Levin syndrome (KLS) is a rare sleep disorder (1­2 cases per million inhabitants) primarily affecting youngKleine-Levin syndrome and bipolar disorder Kleine-Levin syndrome and bipolar disorder

484

Thresholds for Cenozoic bipolar glaciation.  

PubMed

The long-standing view of Earth's Cenozoic glacial history calls for the first continental-scale glaciation of Antarctica in the earliest Oligocene epoch ( approximately 33.6 million years ago), followed by the onset of northern-hemispheric glacial cycles in the late Pliocene epoch, about 31 million years later. The pivotal early Oligocene event is characterized by a rapid shift of 1.5 parts per thousand in deep-sea benthic oxygen-isotope values (Oi-1) within a few hundred thousand years, reflecting a combination of terrestrial ice growth and deep-sea cooling. The apparent absence of contemporaneous cooling in deep-sea Mg/Ca records, however, has been argued to reflect the growth of more ice than can be accommodated on Antarctica; this, combined with new evidence of continental cooling and ice-rafted debris in the Northern Hemisphere during this period, raises the possibility that Oi-1 represents a precursory bipolar glaciation. Here we test this hypothesis using an isotope-capable global climate/ice-sheet model that accommodates both the long-term decline of Cenozoic atmospheric CO(2) levels and the effects of orbital forcing. We show that the CO(2) threshold below which glaciation occurs in the Northern Hemisphere ( approximately 280 p.p.m.v.) is much lower than that for Antarctica ( approximately 750 p.p.m.v.). Therefore, the growth of ice sheets in the Northern Hemisphere immediately following Antarctic glaciation would have required rapid CO(2) drawdown within the Oi-1 timeframe, to levels lower than those estimated by geochemical proxies and carbon-cycle models. Instead of bipolar glaciation, we find that Oi-1 is best explained by Antarctic glaciation alone, combined with deep-sea cooling of up to 4 degrees C and Antarctic ice that is less isotopically depleted (-30 to -35 per thousand) than previously suggested. Proxy CO(2) estimates remain above our model's northern-hemispheric glaciation threshold of approximately 280 p.p.m.v. until approximately 25 Myr ago, but have been near or below that level ever since. This implies that episodic northern-hemispheric ice sheets have been possible some 20 million years earlier than currently assumed (although still much later than Oi-1) and could explain some of the variability in Miocene sea-level records. PMID:18833277

Deconto, Robert M; Pollard, David; Wilson, Paul A; Pälike, Heiko; Lear, Caroline H; Pagani, Mark

2008-10-01

485

The International Society for Bipolar Disorders (ISBD) Task Force Report on Antidepressant Use in Bipolar Disorders  

PubMed Central

Objective The risk-benefit profile of antidepressant medications in bipolar disorder is controversial. When conclusive evidence is lacking, expert consensus can guide treatment decisions. The International Society for Bipolar Disorders (ISBD) convened a task force to seek consensus recommendations on the use of antidepressants in bipolar disorders. Method An expert task force iteratively developed consensus through serial consensus-based revisions using the Delphi method. Initial survey items were based on systematic review of the literature. Subsequent surveys included new or reworded items and items that needed to be rerated. This process resulted in the final ISBD Task Force clinical recommendations on antidepressant use in bipolar disorder. Results There is striking incongruity between the wide use of and the weak evidence base for the efficacy and safety of antidepressant drugs in bipolar disorder. Few well-designed, long-term trials of prophylactic benefits have been conducted, and there is insufficient evidence for treatment benefits with antidepressants combined with mood stabilizers. A major concern is the risk for mood switch to hypomania, mania, and mixed states. Integrating the evidence and the experience of the task force members, a consensus was reached on 12 statements on the use of antidepressants in bipolar disorder. Conclusions Because of limited data, the task force could not make broad statements endorsing antidepressant use but acknowledged that individual bipolar patients may benefit from antidepressants. Regarding safety, serotonin reuptake inhibitors and bupropion may have lower rates of manic switch than tricyclic and tetracyclic antidepressants and norepinephrine-serotonin reuptake inhibitors. The frequency and severity of antidepressant-associated mood elevations appear to be greater in bipolar I than bipolar II disorder. Hence, in bipolar I patients antidepressants should be prescribed only as an adjunct to mood-stabilizing medications. PMID:24030475

Pacchiarotti, Isabella; Bond, David J.; Baldessarini, Ross J.; Nolen, Willem A.; Grunze, Heinz; Licht, Rasmus W.; Post, Robert M.; Berk, Michael; Goodwin, Guy M.; Sachs, Gary S.; Tondo, Leonardo; Findling, Robert L.; Youngstrom, Eric A.; Tohen, Mauricio; Undurraga, Juan; González-Pinto, Ana; Goldberg, Joseph F.; Yildiz, Ay?egül; Altshuler, Lori L.; Calabrese, Joseph R.; Mitchell, Philip B.; Thase, Michael E.; Koukopoulos, Athanasios; Colom, Francesc; Frye, Mark A.; Malhi, Gin S.; Fountoulakis, Konstantinos N.; Vázquez, Gustavo; Perlis, Roy H.; Ketter, Terence A.; Cassidy, Frederick; Akiskal, Hagop; Azorin, Jean-Michel; Valentí, Marc; Mazzei, Diego Hidalgo; Lafer, Beny; Kato, Tadafumi; Mazzarini, Lorenzo; Martínez-Aran, Anabel; Parker, Gordon; Souery, Daniel; Özerdem, Ay?egül; McElroy, Susan L.; Girardi, Paolo; Bauer, Michael; Yatham, Lakshmi N.; Zarate, Carlos A.; Nierenberg, Andrew A.; Birmaher, Boris; Kanba, Shigenobu; El-Mallakh, Rif S.; Serretti, Alessandro; Rihmer, Zoltan; Young, Allan H.; Kotzalidis, Georgios D.; MacQueen, Glenda M.; Bowden, Charles L.; Ghaemi, S. Nassir; Lopez-Jaramillo, Carlos; Rybakowski, Janusz; Ha, Kyooseob; Perugi, Giulio; Kasper, Siegfried; Amsterdam, Jay D.; Hirschfeld, Robert M.; Kapczinski, Flávio; Vieta, Eduard

2014-01-01

486

Bipolar disorder and neurophysiologic mechanisms  

PubMed Central

Recent studies have suggested that some variants of bipolar disorder (BD) may be due to hyperconnectivity between orbitofrontal (OFC) and temporal pole (TP) structures in the dominant hemisphere. Some initial MRI studies noticed that there were corpus callosum abnormalities within specific regional areas and it was hypothesized that developmentally this could result in functional or effective connectivity changes within the orbitofrontal-basal ganglia-thalamocortical circuits. Recent diffusion tensor imaging (DTI) white matter fiber tractography studies may well be superior to region of interest (ROI) DTI in understanding BD. A “ventral semantic stream” has been discovered connecting the TP and OFC through the uncinate and inferior longitudinal fasciculi and the elusive TP is known to be involved in theory of mind and complex narrative understanding tasks. The OFC is involved in abstract valuation in goal and sub-goal structures and the TP may be critical in binding semantic memory with person–emotion linkages associated with narrative. BD patients have relative attenuation of performance on visuoconstructional praxis consistent with an atypical localization of cognitive functions. Multiple lines of evidence suggest that some BD alleles are being selected for which could explain the enhanced creativity in higher-ability probands. Associations between ROI’s that are not normally connected could explain the higher incidence of artistic aptitude, writing ability, and scientific achievements among some mood disorder subjects. PMID:19337455

McCrea, Simon M

2008-01-01

487

Bipolar disorder and neurophysiologic mechanisms.  

PubMed

Recent studies have suggested that some variants of bipolar disorder (BD) may be due to hyperconnectivity between orbitofrontal (OFC) and temporal pole (TP) structures in the dominant hemisphere. Some initial MRI studies noticed that there were corpus callosum abnormalities within specific regional areas and it was hypothesized that developmentally this could result in functional or effective connectivity changes within the orbitofrontal-basal ganglia-thalamocortical circuits. Recent diffusion tensor imaging (DTI) white matter fiber tractography studies may well be superior to region of interest (ROI) DTI in understanding BD. A "ventral semantic stream" has been discovered connecting the TP and OFC through the uncinate and inferior longitudinal fasciculi and the elusive TP is known to be involved in theory of mind and complex narrative understanding tasks. The OFC is involved in abstract valuation in goal and sub-goal structures and the TP may be critical in binding semantic memory with person-emotion linkages associated with narrative. BD patients have relative attenuation of performance on visuoconstructional praxis consistent with an atypical localization of cognitive functions. Multiple lines of evidence suggest that some BD alleles are being selected for which could explain the enhanced creativity in higher-ability probands. Associations between ROI's that are not normally connected could explain the higher incidence of artistic aptitude, writing ability, and scientific achievements among some mood disorder subjects. PMID:19337455

McCrea, Simon M

2008-12-01

488

Anticipation in bipolar affective disorder  

SciTech Connect

Anticipation refers to the increase in disease severity or decrease in age at onset in succeeding generations. This phenomenon, formerly ascribed to observation biases, correlates with the expansion of trinucleotide repeat sequences (TNRs) in some disorders. If present in bipolar affective disorder (BPAD), anticipation could provide clues to its genetic etiology. The authors compared age at onset and disease severity between two generations of 34 unilineal families ascertained for a genetic linkage study of BPAD. Life-table analyses showed a significant decrease in survival to first mania or depression from the first to the second generation (P <.001). Intergenerational pairwise comparisons showed both a significantly earlier age at onset (P < .001) and a significantly increased disease severity (P < .001) in the second generation. This difference was significant under each of four data-sampling schemes which excluded probands in the second generation. The second generation experienced onset 8.9-13.5 years earlier and illness 1.8-3.4 times more severe than did the first generation. In additional analyses, drug abuse, deaths of affected individuals prior to interview, decreased fertility, censoring of age at onset, and the cohort effect did not affect our results. The authors conclude that genetic anticipation occurs in this sample of unilineal BPAD families. These findings may implicate genes with expanding TNRs in the genetic etiology of BPAD. 24 refs., 1 fig., 1 tab.

McInnis, M.G.; McMahon, F.J.; Chase, G.A.; Simpson, S.G.; Ross, C.A.; DePaulo, J.R. Jr. (The Johns Hopkins Univ. School of Medicine, Baltimore, MD (United States))

1993-08-01

489

The Integration and Applications of Organic Thin Film Transistors and Ferroelectric Polymers  

NASA Astrophysics Data System (ADS)

Organic thin film transistors and ferroelectric polymer (polyvinylidene difluoride) sheet material are integrated to form various sensors for stress/strain, acoustic wave, and Infrared (heat) sensing applications. Different from silicon-based transistors, organic thin film transistors can be fabricated and processed in room-temperature and integrated with a variety of substrates. On the other hand, polyvinylidene difluoride (PVDF) exhibits ferroelectric properties that are highly useful for sensor applications. The wide frequency bandwidth (0.001 Hz to 10 GHz), vast dynamic range (100n to 10M psi), and high elastic compliance (up to 3 percent) make PVDF a more suitable candidate over ceramic piezoelectric materials for thin and flexible sensor applications. However, the low Curie temperature may have impeded its integration with silicon technology. Organic thin film transistors, however, do not have the limitation of processing temperature, hence can serve as transimpedance amplifiers to convert the charge signal generated by PVDF into current signal that are more measurable and less affected by any downstream parasitics. Piezoelectric sensors are useful for a range of applications, but passive arrays suffer from crosstalk and signal attenuation which have complicated the development of array-based PVDF sensors. We have used organic field effect transistors, which are compatible with the low Curie temperature of a flexible piezoelectric polymer,PVDF, to monolithically fabricate transimpedance amplifiers directly on the sensor surface and convert the piezoelectric charge signal into a current signal which can be detected even in the presence of parasitic capacitances. The device couples the voltage generated by the PVDF film under strain into the gate of the organic thin film transistors (OFET) using an arrangement that allows the full piezoelectric voltage to couple to the channel, while also increasing the charge retention time. A bipolar detector is created by using a UV-Ozone treatment to shift the threshold voltage and increase the current of the transistor under both compressive and tensile strain. An array of strain sensors which maps the strain field on a PVDF film surface is demonstrated in this work. The strain sensor experience inspires a tone analyzer built using distributed resonator architecture on a tensioned piezoelectric PVDF sheet. This sheet is used as both the resonator and detection element. Two architectures are demonstrated; one uses distributed directly addressed elements as a proof of concept, and the other integrates organic thin film transistor-based transimpedance amplifiers monolithically with the PVDF sheet to convert the piezoelectric charge signal into a current signal for future applications such as sound field imaging. The PVDF sheet material is instrumented along its length and the amplitude response at 15 sites is recorded and analyzed as a function of the frequency of excitation. The determination of the dominant frequency component of an incoming sound is demonstrated using linear system decomposition of the time-averaged response of the sheet using no time domain detection. Our design allows for the determination of the spectral composition of a sound using the mechanical signal processing provided by the amplitude response and eliminates the need for time-domain electronic signal processing of the incoming signal. The concepts of the PVDF strain sensor and the tone analyzer trigger the idea of an active matrix microphone through the integration of organic thin film transistors with a freestanding piezoelectric polymer sheet. Localized acoustic pressure detection is enabled by switch transistors and local transimpedance amplification built into the active matrix architecture. The frequency of detection ranges from DC to 15KHz; the bandwidth is extended using an architecture that provides for virtually zero gate/source and gate/drain capacitance at the sensing transistors and low overlap capacitance at the switch transistors. A series of measurements are taken to demonstrate localized

Hsu, Yu-Jen

490

Panel fabrication utilizing GaAs solar cells  

NASA Technical Reports Server (NTRS)

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.

Mardesich, N.

1984-01-01

491

Comorbid medical illness in bipolar disorder  

PubMed Central

Background Individuals with a mental health disorder appear to be at increased risk of medical illness. Aims To examine rates of medical illnesses in patients with bipolar disorder (n = 1720) and to examine the clinical course of the bipolar illness according to lifetime medical illness burden. Method Participants recruited within the UK were asked about the lifetime occurrence of 20 medical illnesses, interviewed using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) and diagnosed according to DSM-IV criteria. Results We found significantly increased rates of several medical illnesses in our bipolar sample. A high medical illness burden was associated with a history of anxiety disorder, rapid cycling mood episodes, suicide attempts and mood episodes with a typically acute onset. Conclusions Bipolar disorder is associated with high rates of medical illness. This comorbidity needs to be taken into account by services in order to improve outcomes for patients with bipolar disorder and also in research investigating the aetiology of affective disorder where shared biological pathways may play a role. PMID:25359927

Forty, Liz; Ulanova, Anna; Jones, Lisa; Jones, Ian; Gordon-Smith, Katherine; Fraser, Christine; Farmer, Anne; McGuffin, Peter; Lewis, Cathryn M.; Hosang, Georgina M.; Rivera, Margarita; Craddock, Nick

2014-01-01

492

Genetic determinants of white matter integrity in bipolar disorder   

E-print Network

Bipolar disorder is a heritable psychiatric disorder, and several of the genes associated with bipolar disorder and related psychotic disorders are involved in the development and maintenance of white matter in the brain. ...

Sprooten, Emma

2012-06-30

493

Bipolar pulse generator for intense pulsed ion beam accelerator  

SciTech Connect

A new type of pulsed ion beam accelerator named ''bipolar pulse accelerator'' (BPA) has been proposed in order to improve the purity of intense pulsed ion beams. To confirm the principle of the BPA, we developed a bipolar pulse generator for the bipolar pulse experiment, which consists of a Marx generator and a pulse forming line (PFL) with a rail gap switch on its end. In this article, we report the first experimental result of the bipolar pulse and evaluate the electrical characteristics of the bipolar pulse generator. When the bipolar pulse generator was operated at 70% of the full charge condition of the PFL, the bipolar pulse with the first (-138 kV, 72 ns) and the second pulse (+130 kV, 70 ns) was successfully obtained. The evaluation of the electrical characteristics indicates that the developed generator can produce the bipolar pulse with fast rise time and sharp reversing time.

Ito, H.; Igawa, K.; Kitamura, I.; Masugata, K. [Department of Electrical and Electronic System Engineering, University of Toyama, 3190 Gofuku, Toyama 930-8555 (Japan)

2007-01-15

494

Anxiety symptoms and syndromes in bipolar children and adolescents  

Microsoft Academic Search

Anxiety disorders are relatively common in children and adolescents with bipolar disorder. Research to date indicates they\\u000a may impact the onset, course, and treatment response of bipolar illness in children. Anxiety disorders often precede the onset\\u000a of pediatric bipolar disorder. Family studies suggest first-degree relatives of bipolar patients are at increased risk for\\u000a developing mood and anxiety disorders compared with

Edith M. Jolin; Elizabeth B. Weller; Ronald A. Weller

2008-01-01

495

High-Power, High-Frequency Si-Based (SiGe) Transistors Developed  

NASA Technical Reports Server (NTRS)

Future NASA, DOD, and commercial products will require electronic circuits that have greater functionality and versatility but occupy less space and cost less money to build and integrate than current products. System on a Chip (SOAC), a single semiconductor substrate containing circuits that perform many functions or containing an entire system, is widely recognized as the best technology for achieving low-cost, small-siz