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1

GaAs Device Reliability: High Electron Mobility Transistors and Heterojunction Bipolar Transistors  

NASA Astrophysics Data System (ADS)

The two main GaAs-based electronic device technologies are high electron mobility transistors (HEMTs) and heterojunction bipolar transistors (HBTs). Both technologies are commercialized for use in low-noise amplifiers, radar, and fiber optic data transmission systems. In this chapter, we will summarize the degradation mechanisms that limit the lifetime of these devices. A variety of contact and surface degradation mechanisms have been reported but differ in the two device technologies - for HEMTs, the layers are thin and relatively lightly doped compared to HBT structures, and there is a metal Schottky gate that is directly on the semiconductor. By contrast, the HBT relies on pn junctions for current modulation and has only ohmic contacts. This leads to different degradation mechanisms for the two types of devices.

Ren, F.; Douglas, E. A.; Pearton, Stephen J.

2

Chalcogenide glass surface passivation of a GaAs bipolar transistor for unique avalanche terahertz emitters and picosecond switches  

NASA Astrophysics Data System (ADS)

The ultra-narrow ``collapsing'' field domains discovered recently in avalanching GaAs bipolar junction transistor provide a physical basis for designing unique THz emitters and superfast switches. Reliability in devices operating near their volume breakdown voltage requires decisive suppression of premature surface breakdown. We demonstrate here complete, durable surface breakdown suppression through simple deposition of a massive chalcogenide glass layer on the mesa surface by means of a negative charge formed at the interface.

Vainshtein, Sergey; Javadyan, Valeri; Duan, Guoyong; Tsendin, Konstantin; Hovhannisyan, Rafael; Kostamovaara, Juha

2012-02-01

3

Significant Effect of Emitter Area on the Efficiency, Stability and Reliability of Picosecond Switching in a GaAs Bipolar Transistor Structure  

Microsoft Academic Search

A drastic reduction in the residual voltage (from ~ 100 V to a few volts) and a significant (factor of ~ 2) increase in the dU\\/dt switching rate is demonstrated experimentally in the superfast ( ~ 200 ps) avalanche switching of a GaAs bipolar junction transistor with increased emitter area. This result is not a trivial one as only a

Sergey N. Vainshtein; Valentin S. Yuferev; Juha T. Kostamovaara; Marina M. Kulagina; Hannu T. Moilanen

2010-01-01

4

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

5

Femtosecond energy relaxation of nonthermal electrons injected in p-doped GaAs base of a heterojunction bipolar transistor  

SciTech Connect

We study femtosecond relaxation of minority carriers (electrons) injected into a heavily p-doped base of a heterojunction bipolar transistor (HBT). Here, we consider the case of p-doped GaAs, to be specific. The electrons are assumed to have a peaked energy distribution at t=0, with kinetic energies a few hundred meV above the conduction band threshold. We solve the time dependent Boltzmann equation governing the dynamics of these electrons. The main feature of this work is a detailed calculation of the time dependent nonthermal, nonequilibrium electron energy distribution, that relaxes due to single particle excitations via electron{endash}hole scattering and interaction with coupled optical phonon-hole plasmon modes in the sub and picosecond time domains. We highlight the significant role that the electron-hole scattering plays in this relaxation. The majority carriers (holes) are assumed to remain in quasiequilibrium with the lattice, taken to be at room temperature (or at 77 K). We present calculations of electron energy relaxation with the hole density varied from 1{times}10{sup 18} to 1{times}10{sup 20}cm{sup {minus}3}. In the initial, subpicosecond stages of the relaxation, the energy distribution evolves into two major components: a quasiballistic but broad component, at energies near the injection energy, and an energy relaxed component near E=0. The latter becomes dominant in a picosecond or so. The electrons with an initial mean velocity of {similar_to}1.5{times}10{sup 8}cm/s attain a cooler distribution with a mean velocity of {similar_to}4{times}10{sup 7}cm/s within about 1 ps for p doping in excess of 1{times}10{sup 19}cm{sup {minus}3}. The temporal evolution of average velocity {l_angle}v{r_angle} of the electrons should be useful in obtaining values of the base width suitable for effective operation of HBTs. {copyright} 2001 American Institute of Physics.

Prabhu, S. S.; Vengurlekar, A. S.

2001-07-01

6

Ion bipolar junction transistors  

PubMed Central

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

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

2010-01-01

7

Intermodulation in heterojunction bipolar transistors  

Microsoft Academic Search

The modeling of small-signal intermodulation distortion (IMD) in heterojunction bipolar transistors (HBTs) is examined. The authors show that IMD current generated in the exponential junction is partially canceled by IMD current generated in the junction capacitance, and that this phenomenon is largely responsible for the unusually good IMD performance of these devices. Thus, a nonlinear model of the HBT must

Stephen A. Maas; Bradford L. Nelson; Donald L. Tait

1992-01-01

8

Bipolar transistor in VESTIC technology  

NASA Astrophysics Data System (ADS)

VESTIC technology was proposed as an alternative for traditional CMOS technology. It offers a new FET-type twin gate junctionless device called VeSFET. In addition, in the basic VESTIC device structure many different active devices can be made, including bipolar transistors. This allows easy integration of bipolar transistors (called here VeSBJT) with VeSFET transistors. The purpose of this paper is to investigate the expected properties of VeSBJT in order to answer the following questions: are the expected parameters of VeSBJT promising enough to justify further research and fabrication experiments, and will VeSBJTs be technologically compatible with VeSFETs? Our theoretical predictions are based on the concept of effective base width for bipolar transistors with non-plane-parallel emitter and collector junctions. The conclusion is that VeSBJT can be a device with useful characteristics. As a result, VESTIC may have the potential to become a new BiCMOS-type technology.

Ku?micz, Wies?aw; Mierzwi?ski, Piotr

2013-07-01

9

Bipolar Transistor Based on Graphane  

NASA Astrophysics Data System (ADS)

Graphane is a semiconductor with an energy gap, obtained from hydrogenation of the two-dimensional grapheme sheet. Together with the two-dimensional geometry, unique transport features of graphene, and possibility of doping graphane, p and n regions can be defined so that p-n junctions become feasible with small reverse currents. Our recent analysis has shown that an ideal I-V characteristic for this type of junctions may be expected. Here, we predict the behavior of bipolar juncrion transistors based on graphane. Profiles of carriers and intrinsic parameters of the graphane transistor are calculated and discussed.

Gharekhanlou, B.; Tousaki, S. B.; Khorasani, S.

2010-11-01

10

Trends in development of bipolar power transistors  

Microsoft Academic Search

Monolithic integrated circuit technology was applied to bipolar power transistors which included Darlington transistors with preamplification. They are produced with two stabilizing resistors and sometimes also with two diodes for higher switching speed and for overvoltage protection respectively. Darlington transistors have higher current gain than plain silicon transistors of the same size so that they are indispensable for inverters. The

V. A. Potapchuk

1984-01-01

11

Heterojunction bipolar transistors with ion-implanted bases  

NASA Astrophysics Data System (ADS)

Emitter-up configuration heterojunction bipolar transistors (HBTs) fabricated with Zn ion-implanted bases have yielded dc gains of up to 100. This process, in which Zn(+) ions are implanted into a metal organic vapor-deposited GaAs collector epilayer to produce a thin, highly doped base region, could be extended to achieve a fully planar high frequency HTB process for high density ICs.

Tully, J. W.

1986-04-01

12

Fundamental Aspects of Heterojunction Bipolar Transistor Technology.  

National Technical Information Service (NTIS)

Fundamental aspects of heterojunction bipolar transistor (HBT) technology were investigated, including Be diffusion in MBE growth, the effects of epitaxial structure variations on HBT technology, effects of selected device processing methods on HBT perfor...

D. L. Miller P. M. Asbeck

1986-01-01

13

Development of a planar heterojunction bipolar transistor for very high speed logic  

Microsoft Academic Search

The objective of this project was to fabricate multiple heterostructure bipolar transistors in semi-insulating GaAs substrates. During the first year of effort, molecular beam epitaxial growth of doped aluminum-gallium arsenide (AlGaAs) gallium arsenide (GaAs) heterojunctions was carried out. GaAs layers were doped n-type with silicon from the background (1E16) up to 2E18 and p-type with beryllium up to 1E19. N-type

S. I. Long

1983-01-01

14

Field-effect and bipolar power transistor physics  

NASA Astrophysics Data System (ADS)

The book provides an up-to-date account of the progress made in power transistor design. It is written for electrical engineers who design power transistor circuits, device physicists and designers, and university students. Semiconductor surface theory concepts are considered along with semiconductor properties at high carrier concentrations, avalanche breakdown, avalanche breakdown improvement methods, and selected fabrication techniques. Bipolar power transistors are discussed, taking into account power transistor structures, bipolar transistor models, current gain at high carrier concentrations, current-voltage characteristics of power transistors, frequency response, switching transient, microwave transistors, transistor thermal properties, and instabilities. Field-effect (unipolar) transistors are also examined, giving attention to junction field-effect transistors, insulated gate field-effect transistors, and MOS power transistor structures and design considerations.

Blicher, A.

15

Quantum-well resonant tunneling bipolar transistor operating at room temperature  

Microsoft Academic Search

The first resonant tunneling bipolar transistor (RBT) is reported. The AlGaAs\\/GaAs wide-gap emitter device, grown by molecular beam epitaxy (MBE), contains a GaAs quantum well and two AlAs barriers between the emitter and the collector. In the common emitter configuration, when the base current exceeds a threshold value, a large drop in the collector current (corresponding to a quenching of

FEDERICO CAPASSO; SUSANTA SEN; A. C. Gossard; A. L. Hutchinson; J. H. English

1986-01-01

16

Correlation of Photoreflectance Spectra with Performance of GaInP\\/GaAs Heterojunction Bipolar Transistors  

Microsoft Academic Search

We have measured the photoreflectance (PR) spectra at 300 K and dc current gain for GaInP\\/GaAs heterojunction bipolar transistors (HBTs) grown by metalorganic chemical vapor deposition with different growth conditions. From the observed Franz-Keldysh oscillations, we have evaluated the built-in dc electric fields and associated band gaps in the GaInP emitter and GaAs collector regions. The observed increase in current

Yue-Ming Hsin; Ying-Sheng Huang; Chang-Chung Fan; Chen-Hao Wang; Hung-Ming Chen; Nei-Yi Li

2001-01-01

17

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.

18

Lumped Models of Bipolar Transistors and Evaluation of Their Parameters.  

National Technical Information Service (NTIS)

An analysis of several methods for determining experimentally the 'lumped model' parameters of bipolar transistors is presented. All practical problems involved in the measurements are discussed and as a consequence the most appropriate method is suggeste...

H. A. de Mello

1969-01-01

19

Technology development of a planar BiPolar transistor  

Microsoft Academic Search

The project objective is to develop and demonstrate a Silicon Planar BiPolar Transistor incorporating isolation techniques to achieve an improvement in thermal resistance which supports designs for longer pulse widths and duty factors.

Phil Miguelez

1987-01-01

20

IGBT (Insulated Gate Bipolar Transistor) for Power Electronics,  

National Technical Information Service (NTIS)

Thyristors have long been used as power conversion devices. Bipolar Darlington transistor and GTO (gate turn-off thyristors), with their self turn-off characteristics, are particularly well suited to power electronic applications. As Today's more advanced...

V. Sasada H. Takemoto

1988-01-01

21

Heterojunction Bipolar Transistor Technology for Data Acquisition and Communication.  

National Technical Information Service (NTIS)

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...

C. Wang M. Chang S. Beccue R. Nubling P. Zampardi

1992-01-01

22

Single-event burnout of epitaxial bipolar transistors  

SciTech Connect

Single-Event Burnout (SEB) of bipolar junction transistors (BJTs) has been observed nondestructively. It was revealed that all the NPN BJTs, including small signal transistors, with thinner epitaxial layers were inherently susceptible to the SEB phenomenon. It was demonstrated that several design parameters of BJTs were responsible for SEB susceptibility. Additionally, destructive and nondestructive modes of SEB were identified.

Kuboyama, S.; Sugimoto, K.; Shugyo, S.; Matsuda, S. [National Space Development Agency of Japan, Tsukuba, Ibaraki (Japan); Hirao, T. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan)

1998-12-01

23

Calculation of the emitter efficiency of bipolar transistors  

Microsoft Academic Search

The emitter efficiency of a bipolar transistor is calculated taking heavy doping effects such as impurity band formation and band tailing into account. It is shown that in most cases these effects, rather than the minority carrier lifetime in the emitter are limiting the transistor current gain. This allows us to define an effective emitter impurity profile for use in

ROBERT P. MERTENS; HUGO J. DEMAN; ROGER J. VAN OVERSTRAETEN

1973-01-01

24

Parameter-extraction method for heterojunction bipolar transistors  

Microsoft Academic Search

A method for determining the microwave equivalent-circuit element values of a small-signal heterojunction bipolar transistor (HBT) is described. Most important is the ability to separate the parasitic emitter resistance from the junction resistance. No use of `cold' measurements or test patterns is required. The method may also be applicable to homojunction bipolars

S. A. Maas; D. Tait

1992-01-01

25

Monolithic optoelectronic switch based on the integration of a GaAs/AlGaAs heterojunction bipolar transistor and a GaAs vertical-cavity surface-emitting laser  

SciTech Connect

The authors describe the design and the first experimental demonstration of a monolithic integrated optoelectronic switch combining a GaAs/AlGaAs heterojunction bipolar transistor (HBT) with a vertical-cavity surface-emitting laser (VCSEL). The switch has high current gain (500--700), low power dissipation (27 and 55 mW dc at optical output levels of 0.4 and 1.2 mW, respectively, and a high optical output levels of 0.4 and 1.2 mW, respectively), and a high optical-to-electrical conversion efficiency (150 W/A) under dc bias conditions, thus providing a high-performance electrical-to-optical interface for high-speed optical interconnections.

Ping Zhou; Cheng, J. (Univ. of New Mexico, Albuquerque, NM (United States). Center for High Technology Materials); Zolper, J.C.; Lear, K.L.; Chalmers, S.A.; Vawter, G.A. (Sandia National Lab., Albuquerque, NM (United States)); Leibenguth, R.E.; Adams, A.C. (AT and T Bell Labs., Breinigsville, PA (United States))

1993-09-01

26

Effects of displaced p-n junction of heterojunction bipolar transistors  

Microsoft Academic Search

Two-dimensional simulations that demonstrate the effects of displacements of the p-n junctions from the heterojunctions of symmetrical Al0.28Ga0.72\\/GaAs double-heterojunction bipolar transistors (DHBTs) are reported. When the emitter and\\/or collector p-n junctions do not coincide with the AlGaAs\\/GaAs heterojunctions, the electrical characteristics are shown to be drastically altered due to changes in the potential profiles and to changes in recombination rates

Q. M. Zhang; Gen-Lin Tan; W. T. Moore; J. M. Xu

1992-01-01

27

Design optimization of microwave power heterojunction bipolar transistor cells  

Microsoft Academic Search

Results of a design optimization study of power heterojunction bipolar transistor (HBT) cells are presented. AlGaAs-GaAs HBTs have been fabricated using a simple heterostructure design grown by molecular beam epitaxy and a novel self-aligned fabrication process which offers relatively low parasitics. The influence of power transistor cell design on device performance is emphasized. The design optimization study involved simultaneous fabrication

G. W. Wang; L. W. Yang; R. W. Laird; D. A. Williams; J. P. Sadowski; P. D. Wright

1989-01-01

28

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

29

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

30

Bipolar Transistors Can Detect Charge in Electrostatic Experiments  

ERIC Educational Resources Information Center

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

Dvorak, L.

2012-01-01

31

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

32

Characterization and modeling of the power Insulated Gate Bipolar Transistor  

SciTech Connect

The power Insulated Gate Bipolar Transistor (IGBT) is a new switching device designed to overcome the high on-state loss of the power MOSFET. The IGBT behaves as a bipolar transistor which is supplied base current by a MOSFET. The bipolar transistor of the IBGT has a wide base with the base contact at the collector edge of the base and is operated with its base in high-level injection. Because of this, the traditional bipolar transistor models are not adequate for the IBGT and the new model developed in this dissertation must be used. The new model is developed using ambipolar transport and does not assume the quasi-static condition for the transient analysis. The new IBGT model is used to describe measurements for extracting the essential physical device parameters of the model. With these extracted parameters, the new IGBT model consistently describes the measured electrical characteristics of IGBTs with different base lifetimes. The important electrical characteristics of the IGBT are the on-state I-V characteristics, the steady-state saturation current, and the switching transient current and voltage waveforms. The transient waveforms are examined in detail for constant anode voltage switching, clamped inductive load switching, and series resistor, inductor load switching.

Hefner, A.R.

1987-01-01

33

Thermal characterization of thermally-shunted heterojunction bipolar transistors  

Microsoft Academic Search

Heterojunction Bipolar Transistors (HBTs) are potentially useful in a number of microwave applications, but they are severely limited by a current distribution instability caused by electrothermal interaction and the use of a low thermal conductivity substrate. A novel thermal management technique called “thermal shunting” has been developed to reduce thermal resistance and junction temperature non-uniformity. Thermal resistance measurements for thermally-shunted

J. Sewell; L. L. Liou; D. Barlage; J. Barrette; C. Bozada; R. Dettmer; R. Fitch; T. Jenkins; R. Lee; M. Mack; G. Trombley; P. Watson

1996-01-01

34

The Effects of Aging and Hydrogen on the Radiation Response of Gated Lateral PNP Bipolar Transistors  

Microsoft Academic Search

Complex interplay between hydrogen-related defect formation and passivation is observed in irradiated bipolar transistors. Hydrogen soaking experiments are performed to evaluate the dependence of defect buildup and annealing in gated lateral bipolar transistors on hydrogen exposure. Comparisons of the radiation responses of transistors tested in 2009 to identical devices from the same wafer tested in 2003 show that aging has

David. R. Hughart; Ronald D. Schrimpf; Daniel M. Fleetwood; X. Jie Chen; Hugh J. Barnaby; Keith E. Holbert; Ronald L. Pease; Dale G. Platteter; Blair R. Tuttle; Sokrates T. Pantelides

2009-01-01

35

Protection Techniques of Bipolar Power Transistors,  

National Technical Information Service (NTIS)

In order to protect power transistors from overvoltage or overcurrent, it is necessary to know device characteristics and high-voltage withstand capability and further to investigate what sort of duty is caused by what mechanism in actual equipment. The p...

M. Ichijo H. Shigekane

1987-01-01

36

Single epitaxial structure for the integration of lasers with heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

Heterojunction bipolar transistors (HBTs) are capable of producing very high speed digital integrated circuits operating as high as 40 GHz. In this paper we introduce a potentially low cost technique of monolithically integrating in-plane lasers with HBT circuits. A multifunctional epitaxial structure is used which is essentially the same as that for a standard high-speed HBT with modifications made to allow for efficient light amplification. Unlike previous multifunctional epitaxial structures, compromise in the transistor's performance is minimal. The schematic energy band diagrams of the HBT/laser structure biased as an HBT and laser are depicted. Light amplification is achieved by forward biasing the HBT's base- collector junction. The optical gain media is placed in the GaAs collector and consists of strained InGaAs quantum wells (QWs). Under normal HBT operation, the base-collector junction is reverse biased and serves as a sink for electrons which have diffused across the base. To confine electronic carries to the gain region when this junction is forward biased, the subcollector and base consist of a wider bandgap AlGaAs relative to the GaAs collector.

Goyal, Anish K.; Miller, Mark S.; Long, Stephen I.; Leonard, Devin

1994-06-01

37

Optimizing bipolar transistor performance in RF integrated circuits  

Microsoft Academic Search

Bipolar transistors of a 0.6 ?m BiCMOS technology were optimized for better performance in high-frequency circuits. First the lateral and vertical properties of the seven available devices were studied and the effects of scaling were examined. According to the available literature a summary was created about what parasitic elements could be found in the structures. After that some modifications were

J. Katona

2003-01-01

38

A gallium phosphide high-temperature bipolar junction transistor  

Microsoft Academic Search

Preliminary results are reported on the development of a high-temperature (> 350°C) gallium phosphide bipolar junction transistor (BJT) for goethermal and other energy applications. This four-layer p\\/sup +\\/n⁝pp\\/sup +\\/ structure was fromed by liquid phase epitaxy using a supercooling technique to insure uniform nucleation of the thin layers. Magnesium was used as the p-type dopant to avoid excessive out-diffusion into

T. E. Zipperian; L. R. Dawson; R. J. Caffin

1981-01-01

39

Insulated gate bipolar transistor (IGBT) modeling using IG-SPICE  

Microsoft Academic Search

A physics-based model for the insulated gate bipolar transistor (IGBT) is implemented into the widely available circuit simulation package IG-SPICE. Based on analytical equations describing the semiconductor-physics, the model accurately describes the nonlinear junction capacitances, moving boundaries, recombination, and carrier scattering, and effectively predicts the device conductivity modulation. In this paper, the procedure used to incorporate the model into IG-SPICE

C. S. Mitter; A. R. Hefner; D. Y. Chen; F. C. Lee

1994-01-01

40

Monolithic Integration of UHF-MOSFET-Structures and Bipolar UHF Transistors.  

National Technical Information Service (NTIS)

Compatible UHF MOSFET and bipolar monolithic technology for application to FM and television electronic tuners was studied. A UHF MOS tetrode which features very low noise and high transductance, and MOS triodes and UHF bipolar transistors feasible for in...

W. Mueller

1982-01-01

41

Monolithic Integration of UHF-Mosfet-Structures and Bipolar UHF Transistors.  

National Technical Information Service (NTIS)

Compatible UHF MOSFET and bipolar monolithic technology for application to FM and television electronic tuners was studied. A UHF MOS tetrode which features very low noise and high transductance, and MOS triodes and UHF bipolar transistors feasible for in...

W. Mueller

1980-01-01

42

InGaP/InGaAsN/GaAs NpN double-heterojunction bipolar transistor  

SciTech Connect

We have demonstrated a functional NpN double-heterojunction bipolar transistor (DHBT) using InGaAsN for the base layer. The InGaP/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01}/GaAs DHBT has a low V{sub ON} of 0.81 V, which is 0.13 V lower than in a InGaP/GaAs heterojunction bipolar transistor (HBT). The lower turn-on voltage is attributed to the smaller band gap (1.20 eV) of metalorganic chemical vapor deposition-grown In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} base layer. GaAs is used for the collector; thus the breakdown voltage (BV{sub CEO}) is 10 V, consistent with the BV{sub CEO} of InGaP/GaAs HBTs of comparable collector thickness and doping level. To alleviate the current blocking phenomenon caused by the larger conduction band discontinuity between InGaAsN and GaAs, a graded InGaAs layer with {delta} doping is inserted at the base-collector junction. The improved device has a peak current gain of seven with ideal current-voltage characteristics. (c) 2000 American Institute of Physics.

Chang, P. C. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Baca, A. G. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Li, N. Y. [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States); Xie, X. M. [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States); Hou, H. Q. [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States); Armour, E. [Emcore Corporation, Somerset, New Jersey 08873 (United States)

2000-04-17

43

Dead-space corrected GaInP/GaAs composite collector double heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

GaInP/GaAs/GaInP double heterojunction bipolar transistors incorporating dead-space corrected composite collectors were investigated experimentally. The optimized DHBT with a 10-nm lowly doped GaAs spacer and a 5-nm highly doped GaInP spacer has extended the operating range of the collector-emitter voltage, VCE, by maximizing the collector-emitter voltage at the onset of the multiplication, VCE,onset, to 20 V, while minimizing the saturation voltage, VCE,sat (<1 V), and maintaining the nominal breakdown voltage, BVCEO, of the GaInP collector at 25 V. The design incorporating an Al0.11Ga0.89As spacer rather than a GaInP spacer within the lowly doped GaAs-GaInP composite collector demonstrated similar breakdown behavior.

Poh, Z. S.; Yow, H. K.; Ong, D. S.; Houston, P. A.; Krysa, A. B.

2007-04-01

44

Photoresponse characteristics of the heterojunction bipolar transistor  

NASA Astrophysics Data System (ADS)

As the need for high-volume communication systems grows, especially in densely populated areas, so follows the demand for faster, less costly and more reliable network infrastructure. Fiber optics provides plenty bandwidth space that applications such as Local Area Networks (LANs), video and data distribution (eg. CATV, SONET), optically fed wireless systems and remoting of radar, could benefit from it. However the opto-electronic interconnects are major bottlenecks in such systems. The HBT operating as a three-terminal photodetector is potentially the best solution for optoelectronic integrated receivers. It is compatible with post- detection electronics requiring no matching circuits which reduces parasitics and is capable of providing simultaneous gain and amplification at high frequencies. It also requires small bias voltages which leads to lower power consumption, a very attractive characteristic for monolithic circuits. This work presents a comprehensive theoretical and experimental analysis of the HBT under illumination. The study covers static, dynamic and noise properties of these devices when working as photodetectors. Other types of transistors are also investigated such as the MESFET and the HEMT. Experimental results for the three types of transistors are compared to currently used photodiodes (PIN and MSMs). A new HBT photodetector, the optical-HBT, is proposed, implemented and characterized. The new design enhances the sensitivity of conventional HBTs without degrading bandwidth. The optical-HBT is fully compatible with existing electronics, has low power consumption and provides large gain and bandwidth simultaneously.

de Barros, Luiz Eugenio Monteiro, Jr.

1997-11-01

45

Ultrasoon Schakelende Driefasenstroominvertor, Uitgevoerd Met Insulated Gate Bipolar Transistor (Ultrasonic-Switching Three Phase Current Source Inverter with Insulated Gate Bipolar Transistors).  

National Technical Information Service (NTIS)

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 consis...

A. C. Blom

1989-01-01

46

AlGaAs/InGaAsN/GaAs PnP double heterojunction bipolar transistor  

SciTech Connect

The authors demonstrated a functional PnP double heterojunction bipolar transistor (DHBT) using AlGaAs, InGaAsN, and GaAs. The band alignment between InGaAsN and GaAs has a large {triangle}E{sub c} and negligible {triangle}E{sub v}, this unique characteristic is very suitable for PnP DHBT applications. The metalorganic vapor phase epitaxy (MOCVD) grown Al{sub 0.3}Ga{sub 0.7}As/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01}/GaAs PnP DHBT is lattice matched to GaAs and has a peak current gain of 25. Because of the smaller bandgap (E{sub g}=1.20eV) of In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} used for the base layer, this device has a low V{sub ON} of 0.79 V, which is 0.25 V lower than in a comparable Pnp AlGaAs/GaAs HBT. And because GaAs is used for the collector, its BV{sub CEO} is 12 V, consistent with BV{sub CEO} of AlGaAs/GaAs HBTs.

Chang, P.C.; Baca, A.G.; Li, N.Y.; Sharps, P.R.; Hou, H.Q.; Laroche, J.R.; Ren, F.

2000-01-04

47

Single-event burnout of power bipolar junction transistors  

SciTech Connect

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

Titus, J.L. (Naval Weapons Support Center, Crane, IN (United States)); Johnson, G.H.; Schrimpf, R.D.; Galloway, K.F. (Arizona Univ., Tucson, AZ (United States). Dept. of Electrical and Computer Engineering)

1991-12-01

48

A Double Self-Aligned Silicon Bipolar Transistor Utilizing Selectively-Grown Single Crystal Extrinsic Contacts  

Microsoft Academic Search

Feasibility is demonstrated for a unique high speed double self-aligned bipolar junction transistor utilizing monocrystalline silicon base contacts. The transistor is designed for use in high-speed analog or digital applications -where reduced parasitic capacitances and resistances are essential. The device design is unique in reducing extrinsic base\\/collector capacitance over single self-aligned bipolar transistors by using two relatively independent process techniques.

Glenn J. L. Jr; G. W. Neudeck

1992-01-01

49

Phase noise reduction in microwave bipolar transistor amplifiers through active feedback  

Microsoft Academic Search

In this paper, we document the effects of low-frequency active feedback on the 1\\/f phase modulation (PM) noise of linear and compressed SiGe heterojunction bipolar transistor (HBT) and Si bipolar junction transistor (BJT) amplifiers operating at 1GHz. Low noise, high frequency transistors manufactured by NEC were used in a common-emitter (CE) configuration and powered with DC batteries to ensure low

Matthew J. Luce; Eva S. Ferre-Pikal

2004-01-01

50

Device modeling of plastic transfer molding packaged bipolar transistors by use of 3D EM simulations  

Microsoft Academic Search

A method for extracting large signal models of packaged bipolar transistors is described. To circumvent difficulties resulting from complex parasitic surroundings of the inner transistor the modeling procedure has been separated in a number of parts. First of all the inner transistor (chip) was measured using an on wafer probable coplanar environment that could have been well modeled and has

Matthias Rittweger; Andreas Wien; Knut Brenndorfer; Ingo Wolff

1997-01-01

51

Silicon germanium carbon heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

Over the past several years the ternary material Sisb1-x-yGesbxCsby has received considerable attention as a means to extend Si based heterojunction devices. In this work, the advantages and limitations associated with the Sisb1-x-yGesbxCsby/Si material system is explored through the fabrication and electrical analysis of Sisb1-x-yGesbxCsby HBTs. These are the first Sisb1-x-yGesbxCsby HBTs demonstrated by atmospheric pressure chemical vapor deposition, and the first in which ethylene is used as the C precursor. Through the fabrication and characterization of Sisb1-x-yGesbxCsby HBTs, a better understanding of the growth, material properties, processing criteria, and electrical characteristics of the Sisb1-x-yGesbxCsby material system is obtained. Material characterization of the as deposited films, which included Rutherford backscattering spectrometry (RBS), double crystal x-ray diffraction (DXRD), secondary ion mass spectrometry (SIMS), cross-sectional transmission electron microscopy (XTEM), and electrochemical capacitance-voltage (ECV) profiling, finds that the material is single crystal, uniform in composition, and defect free to within the detection limits of these techniques. In addition, DXRD verified strain compensation of the Sisb1-xGesbx films due to the presence of C. However, the C concentration observed by DXRD was consistently lower than that observed by RBS, indicating that a significant portion of the C is non-substitutional. Transistor action is demonstrated from multiple npn Si/Sisb1-x-yGesbxCsby/Si HBTs. However, reduced current gain, increased collector-emitter offset voltage, increased base current, increased series resistance associated with the base, degraded collector current slopes in the forward active Gummel characteristics, and degraded emitter-base junction characteristics are consistently observed for the Sisb1-x-yGesbxCsby HBTs, relative to the Sisb1-xGesbx HBT standards. However, no degradation in the base-collector junction characteristics is observed. Based on the electrical characteristics of the Sisb1-x-yGesbxCsby HBTs, relative to Sisb1-xGesbx HBT standards, and the RBS, DXRD, and XTEM data, it is concluded that the Sisb1-x-yGesbxCsby HBTs contain a high concentration of electrically active defects at the emitter-base interface, and/or the Sisb1-x-yGesbxCsby films are degrading on a microscopic scale (high resolution XTEM found no macroscopic defects) as the deposition progresses, resulting in an increased concentration of electrically active defects near the emitter end of the neutral base. In addition, based on the Gummel characteristics of the HBTs as a function of temperature, the trap concentration estimated from the electrical characteristics, the C concentration detected by DXRD and RBS, and the structure of the ethylene molecule, it is hypothesized that the electrically active traps observed in the Sisb1-x-yGesbxCsby HBTs are associated with Csbs-Csbi defects. Finally, based on the room temperature Gummel characteristics, a preliminary estimate of the bandgap is obtained. Based on these preliminary results, it is found that the bandgap of strained Sisb1-x-yGesbxCsby increases as a function of increasing C concentration at a rate of approximately 7.8-31.2meV/%C.

Balster, Scott Gerard

52

Isolated gate bipolar transistors (IGBT): a solid state switch  

NASA Astrophysics Data System (ADS)

A Copper Vapor Laser Power Supply has been designed using a solid state switch consisting in eighteen Isolated Gate Bipolar Transistors (IGBT),--1200 volts, 400 Amps, each--in parallel. This paper presents the Isolated Gate Bipolar Transistor (IGBTs) replaced in the Power Electronic components evolution, and describes the IGBT conduction mechanism, presents the parallel association of IGBTs, and studies the application of these components to a Copper Vapor Laser Power Supply. The storage capacitor voltage is 820 Volts, the peak current of the solid state switch is 17,000 Amps. The switch is connected on the primary of a step-up transformer, followed by a magnetic modulator. The reset of the magnetic modulator is provided by part of the laser reflected energy with a patented circuit. The charging circuit is a resonance circuit with a charge controlled by an IGBT switch. When the switch is open, the inductance energy is free-wheeled by an additional winding and does not extend the charging phase of the storage capacitor. The design allows the storage capacitor voltage to be very well regulated. This circuit is also patented. The electric pulse in the laser has 30,000 Volt peak voltage, 2000 Amp peak current, and is 200 nanoseconds long, for a 200 Watt optical power Copper Vapor Laser.

Chatroux, D.; Maury, J.; Hennevin, B.

1993-05-01

53

A comparison of GaAs transistors as passive mode mixers  

Microsoft Academic Search

A number of GaAs transistors were evaluated as passive mode mixers with a 10 GHz RF and 2 GHz IF. Both single-tone and two-tone performance were measured for an ion implanted MESFET, spike-doped PsMESFET, a power PsHEMT and a npn power HBT. All were shown to have a substantially lower distortion than a comparable diode mixer. One transistor, the spike-doped

M. J. Schindler; S. L. G. Chu; R. B. Binder

1994-01-01

54

Bipolar snapback in junctionless transistors for capacitorless dynamic random access memory  

NASA Astrophysics Data System (ADS)

In this work, we analyze the snapback effect and extract the effective bipolar current gain in junctionless nanotransistors. The optimal electron and hole concentrations required to trigger and sustain bipolar snapback in junctionless transistors have been evaluated. The occurrence of snapback at lower drain bias (? 2 V) in junctionless devices in comparison to conventional inversion mode transistors demonstrates the enormous potential for static power reduction in capacitorless dynamic random access memories. High values (40-70) of effective bipolar current gain achieved in optimally designed junctionless transistors can be utilized to improve the sensing margin for dynamic memories.

Singh Parihar, Mukta; Ghosh, Dipankar; Alastair Armstrong, G.; Kranti, Abhinav

2012-12-01

55

Hardening measures for bipolar transistors against microwave-induced damage  

NASA Astrophysics Data System (ADS)

In the present paper we study the influences of the bias voltage and the external components on the damage progress of a bipolar transistor induced by high-power microwaves. The mechanism is presented by analyzing the variation in the internal distribution of the temperature in the device. The findings show that the device becomes less vulnerable to damage with an increase in bias voltage. Both the series diode at the base and the relatively low series resistance at the emitter, Re, can obviously prolong the burnout time of the device. However, Re will aid damage to the device when the value is sufficiently high due to the fact that the highest hot spot shifts from the base-emitter junction to the base region. Moreover, the series resistance at the base Rb will weaken the capability of the device to withstand microwave damage.

Chai, Chang-Chun; Ma, Zhen-Yang; Ren, Xing-Rong; Yang, Yin-Tang; Zhao, Ying-Bo; Yu, Xin-Hai

2013-06-01

56

Proton Irradiation Effects on Sb-based Heterojunction Bipolar Transistors  

SciTech Connect

In0.52Al0.48As/In0.39Ga0.61As0.77Sb0.23/In0.53Ga0.47As double heterojunction bipolar transistors (DHBTs) were irradiated with 5 MeV protons at fluences from 2 1011 to 2 1015 protons/cm2. The radiation produced significant increases in generation-recombination leakage current in both emitter-base and base-collector junctions. The DHBTs irradiated with a dose of 2 1011 cm-2, which was equivalent to around 40 years of exposure in low earth orbit, showed minimal changes in the junction ideality factor, generation recombination leakage current, current gain and output conductance. The InAlAs/InGaAsSb/InGaAs DHBTs appear to be well-suited to space or nuclear industry applications.

Lo, C. F. [University of Florida; Kim, H.-Y. [Korea University; Kim, J. [Korea University; Chen, Shu-han [National Central University, Taiwan; Wang, Sheng-yu [National Central University, Taiwan; Chyi, Jen-inn [National Central University, Taiwan; Chou, B.Y. [University of Florida, Gainesville; Chen, K.H. [University of Florida, Gainesville; Wang, Y.l. [University of Florida; Chang, C. Y. [University of Florida; Pearton, S. J. [University of Florida; Kravchenko, Ivan I [ORNL; Jang, S. [Dankook University, Korea

2009-01-01

57

Current Distribution Analysis of Insulated Gate Bipolar Transistor Cells  

NASA Astrophysics Data System (ADS)

In current insulated gate bipolar transistor (IGBT) technology, a corner or centered gate pad is employed with polycrystalline silicon (poly-Si) to form the metal oxide semiconductor (MOS) gate structure which forms a resistor-capacitor (RC) network across the die. This paper presents, for the first time, an analysis using circuit simulator, SABER, to analyze its influence on the internal behavior of the IGBT. The difference in the interconnect gate impedance between each cathode cells is found to influence their gate drive voltages, which results in the divergence of collector current within each cathode cells during transient periods. Proper distribution of the poly-Si gate impedance is necessary to achieve uniformity of current distribution in the device.

Hongyao Long,; Mark R. Sweet,; Luther-King Ngwendson,; E. M. Sankara Narayanan,

2010-04-01

58

Evaluation of transport properties of ozonized poly\\/mono interfaces in polysilicon emitter bipolar transistors  

Microsoft Academic Search

Temperature-dependent electrical measurements have been performed to determine hole and electron transport properties across the poly\\/mono interface in polysilicon emitter bipolar transistors. A tunneling probability has been extracted, and the results are correlated with noise parameters.

S. Niel; A. Chantre; P. Llinarčs; M. Laurens; G. Vincent

2000-01-01

59

Monte Carlo Approach to Transient Analysis of HBT's (Heterojunctions bipolar transistors) with Different Collector Designs,  

National Technical Information Service (NTIS)

The transient analysis of heterojunction bipolar transistors (HBT's) using the Monte Carlo technique is presented for the first time. Three HBT structures with conventional (A), inverted field (B), and undoped collector (C) were simulated. The transient b...

G. I. Haddad J. Hu K. Tomizawa D. Pavlidis

1989-01-01

60

Lateral bipolar transistor's extrinsic base design for better fT vs BVCEO solution  

Microsoft Academic Search

In modern fast bipolar transistor design, high frequency performance and current operating level are traded off with breakdown voltages. Charge sharing between extrinsic and intrinsic base acceptors reduces the maximum electric field in the intrinsic transistor and improves BVCEO. Extrinsic base can be optimized and higher breakdown voltage can be obtained without severely degrading high frequency performance. This was shown

M. Koricic; P. Biljanovic; T. Suligoj

2004-01-01

61

The influence of surface treatments on the electrical characteristics of polysilicon emitter bipolar transistors  

Microsoft Academic Search

Silicon bipolar transistors have been made with arsenic-implanted or phosphorus-diffused polysilicon emitters. The effects of different surface treatments, prior to polysilicon deposition, are investigated by comparing results obtained for a dip etch in hydrofluoric acid with those for an RCA clean. Detailed electrical results are presented for these two types of device, including transistor characteristics as a function of temperature.

B. Soerowirdjo; P. Ashburn; A. Cuthbertson

1982-01-01

62

Use of narrow collector layers in Si and Si 1? x Ge x bipolar transistors  

Microsoft Academic Search

This paper describes the use of narrow collector layers in planar LOCOS isolated Si and SiGe bipolar transistors. The transistors have been fabricated using either a single or double epi process in order to compare the doping control in the collector layer. In contrast with the conventional double epi process, in the single epi process, the collector, base and emitter

W. Y. Leong; A. C. Churchill; D. J. Robbins; A. Lambert

1997-01-01

63

Bridging the gap between microscopic and macroscopic theories of noise in bipolar junction transistors  

Microsoft Academic Search

The major noise sources in a bipolar transistor are the base resistance thermal noise, or Johnson noise, the base current shot noise and the collector current shot noise. The shot noise is described by a spectral density of 2qI, I being the DC base, IB, or collector, IC, current. We present a detailed microscopic treatment of the transistor collector current

G. Niu

2004-01-01

64

Fabrication of submicron microwave bipolar transistors by direct write electron beam lithography  

Microsoft Academic Search

To study the effects of reducing the lateral dimensions of bipolar transistors to values below 1 żm, a production process based on optical lithography, is adapted to fabricate submicron sized interdigitated microwave transistors. The emitter, base contact, and metallization patterns are defined by direct write electron beam lithography. For alignment of the patterns, special registration marks on (111) Si-wafers, compatible

M. N. Webster; A. H. Verbruggen; J. Romijn; H. F. F. Jos; P. M. A. Moors; S. Radelaar

1992-01-01

65

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

66

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

67

Characteristics of Novel InGaAsN Double Heterojunction Bipolar Transistors  

SciTech Connect

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

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

2000-08-01

68

InGaAsN/AlGaAs Pnp Heterojunction Bipolar Transistor  

SciTech Connect

The authors have demonstrated a functional Pnp heterojunction bipolar transistor (HBT) using InGaAsN. The metalorganic vapor phase epitaxy (MOCVD) grown Al{sub 0.3}Ga{sub 0.7}As/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} HBT takes advantage of the narrower bandgap energy (E{sub g} = 1.25eV) of In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01}, which is lattice matched to GaAs. Compared with the Al{sub 0.3}Ga{sub 0.7}As/GaAs material system, the Al{sub 0.3}Ga{sub 0.7}As/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} material system has a larger conduction band offset, while the valence band offset remains comparable. This characteristic band alignment is very suitable for Pnp HBT applications. The device's peak current gain is 23 and it has a turn on voltage of 0.77V, which is 0.25V lower than in a comparable Pnp Al{sub 0.3}Ga{sub 0.7}As/GaAs HBT.

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

1999-11-03

69

A low-noise K-Ka band oscillator using AlGaAs/GaAs heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

The design considerations, fabrication process, and performance of the first K-Ka-band oscillator implemented using a self-aligned AlGaAs/GaAs heterojunction bipolar transistor (HBT) are described. A large-signal time-domain-based design approach has been used which applies a SPICE-F simulator for optimization of the oscillator circuit parameters for maximum output power. The oscillator employs a 2 x 10 sq mm emitter AlGaAs/GaAs HBT that was fabricated using a pattern inversion technology. The HBT has a base current 1/f noise power density lower than 1 x 10 to the -20th sq A/Hz at 1 kHz and lower than 1 x 10 to the -22nd sq A/Hz at 100 kHz for a collector current of 1 mA. The oscillator, which is composed of only low-Q microstrip transmission lines, has a phase noise of -80 dBc/Hz at 100 kHz off carrier when operated at 26.6 GHz. These results indicate the applicability of the HBTs to low-phase-noise monolithic oscillators at microwave and millimeter-wave frequencies, where both Si bipolar transistors and GaAs FETs are absent.

Madihian, Mohammad; Takahashi, Hideki

1991-01-01

70

Exploratory Development of SiC Bipolar Transistors and GaN heterojunction Bipolar Transistors for High-Power Switching Applications.  

National Technical Information Service (NTIS)

Homojunction bipolar transistors (BJTs) have been designed, fabricated, and characterized in 4H-SiC Devices optimized for high current gain have betas as high as 55, a new record for SiC BJTs. Devices optimized for blocking voltage exhibit blocking voltag...

J. A. Cooper

2003-01-01

71

Design of GaAs MMIC transistors for the low-power low noise applications  

Microsoft Academic Search

The paper investigates the problem of minimizing bias power for the low noise GaAs amplifiers. The model of the amplifier parameters versus transistor gate width is presented and used to derive the conditions for noise optimization. It is shown that optimum FETs are rather wide and may operate at very low current densities. Complete amplifier stages with only 3-5 mW

Zbigniew M. Nosal

2000-01-01

72

Near-ideal transport in an AlGaAs/GaAs heterostructure bipolar transistor by Na2S-9H2O regrowth  

NASA Astrophysics Data System (ADS)

It is demonstrated that the deposition of thin films of Na2S-9H2O onto small area AlGaAs/GaAs heterostructure bipolar transistors (HBTs) leads to almost total suppression of parasitic 2 kT recombination at the device periphery. By reducing the GaAs surface recombination velocity, HBTs with nearly ideal transport characteristics have been obtained. The results offer the hope that a broad class of minority-carrier devices can be scaled to submicrometer dimensions without degradation in their performance.

Nottenburg, R. N.; Sandroff, C. J.; Humphrey, D. A.; Hollenbeck, T. H.; Bhat, R.

1988-01-01

73

Gallium arsenide-based epitaxial structures for heterojunction bipolar transistors with increased efficiency  

NASA Astrophysics Data System (ADS)

AlGaAs/GaAs/GaAs and GaInP/GaAs/GaAs Npn heterojunction bipolar transistors (HBTs) are now in widespread use in microwave power amplifiers. In this Dissertation, improved HBT structures are presented to address issues currently problematic for these devices: high turn-on voltage, high offset and knee voltages, and saturation charge storage. For a variety of applications, particularly operation with low power supply voltage and reduced power dissipation, it would be desirable to have a smaller value of turn-on voltage (VBE). In this Dissertation, the design of reduced VBE GaAs-based HBTs was investigated using GaInNAs in the base region. In order to gain understanding of the effect of nitrogen on these devices, GaInNAs-base HBTs with varying amounts of nitrogen, were fabricated and characterized which yielded devices with varying reductions in VBE. In devices with a large reduction in VBE of 0.4 V the minority carrier diffusion length (Ldiff) was reduced to 0.1 mum, which is considerably lower than that of GaAs (Ldiff = 0.5 mum). This resulted in lower current gain and longer base transit time. Devices with a smaller reduction of VBE of 90 mV also had a reduced Ldiff of 0.4 mum. However, with graded composition in the base, the minority carrier transport of GaInNAs-base HBTs was significantly improved. The resulting HBT had an 80 mV VBE with larger current gain and comparable fT to the GaAs device. The second part of this Dissertation deals with the reduction of the offset (VCE,sat) and knee (Vk) voltages as well as saturation charge storage in HBTs fabricated with the GaInP/GaAs material system. Reduced HBT offset and knee voltages are important to improve the power amplifier efficiency. Switching mode power amplifiers are particularly attractive for high efficiency applications, but to improve their performance it is necessary to reduce the HBT saturation charge storage. It is shown in this Dissertation that HBT structures using a 100 A thick layer of GaInP between the GaAs base and collector layers are effective in reducing VCE,sat to 30 mV and Vk to 0.3 V (while for conventional HBTs VCE,sat = 0.2 V and Vk = 0.5 V are typical). A 5-fold reduction in saturation charge storage is simultaneously obtained.

Welty, Rebecca Jane

74

Device characteristics of the PnP AlGaAs/InGaAsN/GaAs double heterojunction bipolar transistor  

SciTech Connect

The authors have demonstrated a functional PnP double heterojunction bipolar transistor (DHBT) using AlGaAs, InGaAsN, and GaAs. The band alignment between InGaAsN and GaAs has a large {triangle}E{sub C} and a negligible {triangle}E{sub V}, and this unique characteristic is very suitable for PnP DHBT applications. The metalorganic vapor phase epitaxy (MOCVD) grown Al{sub 0.3}Ga{sub 0.7}As/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01}/GaAs PnP DHBT is lattice matched to GaAs and has a peak current gain of 25. Because of the smaller bandgap (Eg = 1.20 eV) of In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} used for the base layer, this device has a low V{sub ON} of 0.79 V, which is 0.25 V lower than in a comparable Pnp AlGaAs/GaAs HBT. And because GaAs is used for the collector, its BV{sub CEO} is 12 V, consistent with BV{sub CEO} of AlGaAs/GaAs HBTs of comparable collector thickness and doping level.

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

2000-02-09

75

Extraction Enhanced Lateral Insulated Gate Bipolar Transistor: A Super High Speed Lateral Insulated Gate Bipolar Transistor Superior to Lateral Dobule Difused Metal Oxide Semiconductor Field-Effect Transistor  

NASA Astrophysics Data System (ADS)

We have successfully developed novel extraction enhanced lateral insulated gate bipolar transistors (E2LIGBTs) in conventional silicon on insulator (SOI) wafers, which exhibit super-high speed switching of 34 ns turn-off time and a low on-state voltage of 3.7 V at 84 A/cm2 simultaneously with a high breakdown voltage of 738 V. This is the first report showing its superior switching speed and on-resistance compared to conventional lateral double diffused metal oxide semiconductor field-effect transistor (LDMOS). The superior performance is achieved by a new anode structure designed with the proposed E2 concept, which simultaneously achieves enhanced electron extraction and suppression of hole injection at the anode region without life time control. The E2 concept is realized using the anode structure, consisting of a narrow p+-injector and a wide Schottky contact on a lightly doped p-layer over an n-buffer. The switching speed can be controlled by the area ratio of the Schottky area over the injector area.

Ashida, Youichi; Takahashi, Shigeki; Shiraki, Satoshi; Tokura, Norihito; Nakagawa, Akio

2012-04-01

76

A 40 GHz fT Si bipolar transistor LSI technology  

Microsoft Academic Search

A high-speed Si bipolar transistor with fT (cutoff frequency) of 40 GHz using advanced BSA (BSG self-aligned) technology is described. The advanced BSA technology is characterized by graded profiled collector, buried emitter electrode structure, and 0.8-?m design rule. The advanced BSA technology for further improving the fT performance of the sub-100-nm-deep base transistor has been developed by adding these three

M. Sugiyama; H. Takemura; C. Ogawa; T. Tashiro; T. Morikawa; M. Nakamae

1989-01-01

77

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

Microsoft Academic Search

A RF Bipolar Transistor integrated to a standard 0.35ľm CMOS process is presented. This BiCMOS technology features a single-poly NPN transistor with simulated performance of f? = 16GHz and BVCEO = 6.4V. With implanted base and no trench isolation, this device offers full compatibility with standard CMOS technology at the cost of three additional mask layers, while demonstrates good performance

I-Shan Michael Sun; Wai Tung Ng; Philip K. T. Mok; Hidenori Mochizuki; Katsumi Shinomura; Hisaya Imai; Akira Ishikawa; Nobuo Saito; Kiyoshi Miyashita; Satoru Tamura; Kaoru Takasuka

78

Development on the high-speed bipolar transistor with BF\\/sub 2\\/-implanted thin base  

Microsoft Academic Search

The polysilicon emitter bipolar process technology in which BF2-implanted base layer and rapid thermal anneal (RTA) are used has been reported. The process and device have been simulated by TSUPREM4 and MEDICI software respectively. High-speed NPN Transistor with beta of 160, fT of 9.5GHz and BVCEO of 6.0V has been achieved. Based on the NPN transistor, broad-band amplifier with bandwidth

Yang Qiudong; Li Rongqiang; Tan Kaizhou; Zhang Jing; Zhong Yi; He Kaiquan; LiuYukui

2006-01-01

79

An IGBT and MOSFET gated SiC bipolar junction transistor  

Microsoft Academic Search

A high voltage 4H-SiC bipolar junction transistor (BJT) has been developed with 16 A, 600 V rating. This paper presents a new base drive structure for the SiC BJT for inverter application. The driver consists of one IGBT and one MOSFET to help turn-on and turn-off of the SiC BJT transistor in a Darlington like configuration. Instead of using conventional

Huijie Yu; Jason Lai; X. Li; Y. Luo; L. Fursin; J. H. Zhao; P. Alexandrov; B. Wright; M. Weiner

2002-01-01

80

Schottky Collector Bipolar Transistor Without Impurity Doped Emitter and Base: Design and Performance  

NASA Astrophysics Data System (ADS)

In this paper, we report an alternative approach of implementing a Schottky collector bipolar transistor without doping the ultrathin SOI film. Using different metal work function electrodes, the electrons and holes are induced in an intrinsic silicon film to create the n emitter and the p base regions, respectively. Using two-dimensional device simulation, the performance of the proposed device has been evaluated. Our results demonstrate that the charge plasma based bipolar transistor with Schottky collector exhibits a high current gain and a better cut-off frequency compared to its conventional counterpart.

Nadda, Kanika; Kumar, M. Jagadesh

2013-09-01

81

InGaAsN/AlGaAs P-n-p heterojunction bipolar transistor  

SciTech Connect

We have demonstrated a functional P-n-p heterojunction bipolar transistor (HBT) using InGaAsN. The metalorganic-vapor-phase-epitaxy-grown Al{sub 0.3}Ga{sub 0.7}As/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} HBT takes advantage of the narrower band gap energy (E{sub g}=1.2 eV) of In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01}, which is lattice matched to GaAs. Compared with the Al{sub 0.3}Ga{sub 0.7}As/GaAs material system, the Al{sub 0.3}Ga{sub 0.7}As/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} material system has a larger conduction-band offset, while the valence-band offset remains comparable. This characteristic band alignment is very suitable for P-n-p HBT applications. The device's peak current gain is 23, and it has a turn-on voltage of 0.77 V, which is 0.25 V lower than in a comparable P-n-p Al{sub 0.3}Ga{sub 0.7}As/GaAs HBT. (c) 2000 American Institute of Physics.

Chang, P. C. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Baca, A. G. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Li, N. Y. [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States); Sharps, P. R. [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States); Hou, H. Q. [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States); Laroche, J. R. [Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States); Ren, F. [Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States)

2000-05-08

82

Minimizing gain degradation in lateral PNP bipolar junction transistors using gate control  

SciTech Connect

Gain degradation in lateral PNP bipolar junction transistors is minimized by controlling the potential of a gate terminal deposited above the active base region. Gate biases that deplete the base during radiation exposure establish electric fields in the base oxide that limit the generation of oxide defects. Conversely, gate biases that accumulate the base during device operation suppress gain degradation by decreasing the probability of carrier recombination with interface states. The results presented in this paper suggest that, for gate controlled LPNP transistors designed for operation in radiation environments, a dynamic control of the gate potential improves the transistor's radiation hardness and extend its operating life.

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

1999-12-01

83

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

Microsoft Academic Search

Electrostatic discharge (ESD) phenomena involve both electrical and thermal effects, and a direct electrostatic discharge to an electronic device is one of the most severe threats to component reliability. Therefore, the electrical and thermal stability of multifinger microwave bipolar transistors (BJTs) under ESD conditions has been investigated theoretically and experimentally. 100 samples have been tested for multiple pulses until a

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

2011-01-01

84

Polysilicon emitters for bipolar transistors: a review and re-evaluation of theory and experiment  

Microsoft Academic Search

A critical review is presented of the theories proposed in the literature to explain the current gain enhancement of polysilicon emitter bipolar transistors. From these theories a simplified analytical formulation is chosen which models the blocking properties of the interface, including tunneling through the interfacial oxide, reduced grain boundary mobility at the polysilicon\\/silicon interface, and the potential barrier created by

Ian R. C. Post; P. Ashburn; Graham R. Wolstenholme

1992-01-01

85

A breakdown model for the bipolar transistor to be used with circuit simulators  

NASA Astrophysics Data System (ADS)

A breakdown model for the output characteristics of the bipolar transistor (bjt) has been developed. The behavioral modeling capability of PSPICE, a popular SPICE program (with emphasis on integrated circuits) was used to implement the macromodel. The model predicts bjt output characteristics under breakdown conditions. Experimental data was obtained to verify the macromodel. Good agreement exists between the measured and the simulated results.

Keshavarz, A. A.; Raney, C. W.; Campbell, D. C.

86

Merged-transistor logic (MTL)-a low-cost bipolar logic concept  

Microsoft Academic Search

The authors describe a novel bipolar logic featuring a direct injection of minority carriers into the switching transistor. MTL is based on inverters having decoupled multicollector outputs for the logical combinations. The devices are self-isolated and no ohmic load resistors are required. This is a key to monolithic logic chips of very high functional density and low power dissipation. On

H. H. Berger; S. K. Wiedmann

1972-01-01

87

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

88

Analytical modeling of device-circuit interactions for the power insulated gate bipolar transistor (IGBT)  

Microsoft Academic Search

The device-circuit interactions of the power insulated gate bipolar transistor (IGBT) for a series resistor-inductor load, both with and without a snubber, are simulated. An analytical model for the transient operation of the IGBT, previously developed, is used in conjunction with the load circuit state equations for the simulations. The simulated results are compared with experimental results for all conditions.

1990-01-01

89

300 Degree C GaN/AlGaN Heterojunction Bipolar Transistor  

SciTech Connect

A GaN/AIGaN heterojunction bipolar transistor has been fabricated using C12/Ar dry etching for mesa formation. As the hole concentration increases due to more efficient ionization of the Mg acceptors at elevated temperatures (> 250oC), the device shows improved gain. Future efforts which are briefly summarized. should focus on methods for reducing base resistance.

Abernathy, C.R.; Baca, A.G.; Cho, H.; Chow, P.P.; Han, J.; Hichman, R.A.; Jung, K.B.; Kopf, R.F.; La Roche, J.R.; Pearton, S.J.; Ren, F.; Shul, R.J.; Van Hove, J.M.; Wilson, R.G.

1998-10-14

90

Low-noise high-power heterojunction bipolar transistors for mixed-mode applications  

Microsoft Academic Search

A novel AlGaAs-GaAs heterojunction bipolar transistor (HBT), which provides state-of-the-art noise and record power density through X-band, was developed. This performance is due to advanced design and fabrication techniques. This HBT is readily transferable to mixed-mode applications, such as portable telephones and radar transmit\\/receive modules

T. Jenkins; D. Barlage; J. Barrette; R. Lee; L. Liou; C. Bozada; R. Dettmer; R. Fitch; M. Mack; J. Sewell

1995-01-01

91

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

National Technical Information Service (NTIS)

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

G. K. Ovrebo

2004-01-01

92

Effect of aging on radiation response of bipolar transistors  

Microsoft Academic Search

A thermally activated aging process is investigated by experimental evaluation of the change in radiation response of test PNP and NPN transistors over a wide range of emitter-base bias conditions after preirradiation elevated-temperature stress and infrared illumination. A comparison of radiation response after temperature stress for transistors with rather different ages is investigated. For \\

V. S. Pershenkov; A. Y. Slesarev; A. V. Sogoyan; V. V. Belyakov; V. B. Kekukh; A. Y. Bashin; D. V. Ivashin; V. S. Motchkine; V. N. Ulimov; V. V. Emelianov

2001-01-01

93

Topics on GaAs integrated circuit: GaAs grown on Si substrates, field-effect transistors, and electro-optic probing technique  

SciTech Connect

The possibility of integrating GaAs devices with Si devices by means of heteroepitaxy growth on Si is considered. The GaAs films are grown on Si substrates by molecular beam epitaxy. The material defects and thermal-induced stress in GaAs films are two fundamental problems of particular interests. The defects are mainly due to the inclined interface dislocations and stacking faults. It was found that these defects can be reduced if GaAs is grown on a clean and double-stepped Si surface. Various kinds of field-effect transistors (FET's) are demonstrated and analyzed. The buried-gate junction FET made by a submicron self-aligned process achieves a transconductance of 180 mS/mm. Besides, no back-gating effect is observed in this kind of device. Another novel device named as top-back-gate FET is also reported. In order to characterize the GaAs material and device in a non-invasive way, the author developed the electro-optic probing technique. Because the refractive indices of GaAs are modified by electric fields, he could obtain the information about internal fields in GaAs devices or material from the phase retardation of a probing beam. The experimental results in potential profile probing of various device structures are reported.

Lo, Y.

1987-01-01

94

Use of electron-beam irradiation to study performance degradation of bipolar transistors after reverse-bias stress  

Microsoft Academic Search

Degradation of the electrical characteristics of a bipolar transistor results from reverse-biasing the emitter-base junction and from irradiation with energetic electrons. The authors compare the degradation of advanced, self-aligned bipolar transistors by these two means. DC and AC characteristics of single devices are compared, showing that, apart from minor differences, the effects are similar. By cross-calibrating, it is therefore possible

K. A. Jenkins; J. D. Cressler; J. D. Warnock

1991-01-01

95

Detector embedded device for continuous reset of charge amplifiers: choice between bipolar and MOS transistor  

NASA Astrophysics Data System (ADS)

This work discusses the criteria for the choice of the reset device in a charge amplifier whose front-end is integrated on high-resolution semiconductor detectors. The performances achievable using a bipolar or a MOS transistor as reset device are compared in terms of the linearity of the response and of the added noise as a function of the detector leakage current. The additional constraints in term of available technology and layout compatibility show the advantages of MOS transistors operated in sub-threshold mode.

Guazzoni, C.; Sampietro, M.; Fazzi, A.

2000-04-01

96

Effects of Photowashing Treatment on Gate Leakage Current of GaAs Metal-Semiconductor Field-Effect Transistors  

NASA Astrophysics Data System (ADS)

Effects of photowashing treatment on gate leakage current (IGD) of a GaAs metal-semiconductor field-effect transistor were studied by observing changes in atomic composition and band bending at the surface of GaAs through X-ray photoemission spectroscopy. The photowashing treatment produces Ga2O3 on the surface of GaAs, leaving acceptor-type Ga antisites behind under the oxide. The Ga antisites played a role in reducing the maximum electric field at the drain edge of the gate, leading to the decrease of IGD. The longer photowashing time produced thicker oxide on the surface of GaAs, acting as a conducting pass for electrons, leading to the increase of IGD.

Choi, Kyoung Jin; Moon, Jae Kyoung; Park, Min; Kim, Haechon; Lee, Jong-Lam

2002-05-01

97

SEU-hardened silicon bipolar and GaAs MESFET SRAM cells using local redundancy techniques  

SciTech Connect

Silicon bipolar and GaAs FET SRAM's have proven to be more difficult to harden with respect to single-event upset mechanisms than have silicon CMOS SRAM's. This is a fundamental property of bipolar and JFET or MESFET device technologies which do not have a high-impedance, nonactive isolation between the control electrode and the current or voltage being controlled. All SEU circuit level hardening techniques applied at the local level must use some type of information storage redundancy so that information loss on one node due to an SEU event can be recovered from information stored elsewhere in the cell. In CMOS technologies, this can be achieved by the use of simple cross-coupling resistors, whereas in bipolar and FET technologies, no such simple approach is possible. Several approaches to the use of local redundancy in bipolar and FET technologies are discussed in this paper. At the expense of increased cell complexity and increased power consumption and write time, several approaches are capable of providing complete SEU hardness at the local cell level.

Hauser, J.R. (Dept. of Electrical and Computer Engineering, North Carolina State Univ., Raleigh, NC (US))

1992-02-01

98

Material and device studies for the development of gallium nitride heterojunction bipolar transistors by molecular beam epitaxy  

Microsoft Academic Search

Due to its unique physical properties, gallium nitride (GaN) is under intense investigation for the development of transistors for high power, high frequency and high temperature applications. The majority of existing literature addresses field effect transistors. This dissertation addresses a wide spectrum of materials and device studies required for the development of GaN-based heterojunction bipolar transistors (HBTs). The investigated structure

Wei Li

2008-01-01

99

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

SciTech Connect

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.

1988-12-26

100

Cryogenically cooled broad-band GaAs field-effect transistor preamplifier  

SciTech Connect

A cryogenically cooled 1-2 GHz low-noise broad-band prototype preamplifier utilizing GaAs field-effect transistors is described. The preamplifier has an average gain of 30 dB at ambient temperatures of 293/sup 0/K and 18/sup 0/K, respectively. The noise figure has a minimum value of 0.75dB at 300/sup 0/K and 0.24dB 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 phaseshift 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.

1984-02-01

101

The effect of bandgap engineering on IC-VBE fly-back characteristic of power SiGe heterojunction bipolar transistor  

Microsoft Academic Search

The effect of bandgap engineering on IC-VBE flyback characteristic of power SiGe heterojunction bipolar transistor is studied through theoretical analysis, computer simulations, and experimental measurements. It is found that because of the existence of Ge composition, SiGe Heterojunction Bipolar Transistors have better thermal stability compared with homojunction bipolar transistors under the same operating condition which will be beneficial to decrease

Chen Liang; Zhang Wan-rong; Jin Dong-yue; Ding Chun-bao; Zhang Yu-jie; Lu Zhi-yi

2011-01-01

102

Double-interdigitated (TIL) bipolar power transistors with lightly doped collectors  

Microsoft Academic Search

The results of an investigation concerning the implementation of the two-interdigitation-level (TIL) concept in TO-3-packaged, triple-diffused bipolar power n-p-n transistors with lightly doped collector are discussed. It is demonstrated that the TIL concept, which offers a fair balance between manufacturability ease\\/cost effectiveness and overall electrical performances, allows for an increase of both the DC and small-signal current gains and the

A. Silard; G. Nani; F. Floru; C. Stefan

1988-01-01

103

The use of amorphous and microcrystalline silicon for silicon heterojunction bipolar transistors  

Microsoft Academic Search

The modification of the emitter structure of silicon bipolar transistors results in more freedom in the choice between sometimes conflicting device parameters. The approach followed in this work is the use of an amorphous silicon (a-Si:H) or microcrystalline silicon (ľc-Si) emitter, creating a real heterojunction with the crystalline silicon base. Due to the larger bandgap of these emitter materials, the

J. Symons; M. Ghannam; J. Nijs; A. van Ammel; P. de Schepper; A. Neugroschel; R. Mertens

1986-01-01

104

Generalized analytical transport modeling of the DC characteristics of heterojunction bipolar transistors  

Microsoft Academic Search

The current transport mechanisms in double-heterojunction bipolar transistors, including the effects of conduction-band discontinuities of spikes, is analyzed. Two approaches, one based on the back-and-forth motion of electrons in the base between confining spikes and the other on the solution of the continuity equation in the base, are shown to be equivalent. The simplified derivation of the Ebers-Moll-like terminal current

Tae-Woo Lee; Peter A. Houston

1993-01-01

105

Lamp-heated rapid vapor-phase doping technology for 100GHz Si bipolar transistors  

Microsoft Academic Search

High-speed Si bipolar transistor technology that uses lamp-heated Rapid Vapor-phase Doping (RVD) for shallow base formation is demonstrated. By applying RVD to a self-aligned metal\\/IDP (SMI) base electrode structure, excellent characteristics, 82-GHz fT and 92-GHz fmax, were obtained simultaneously. Devices with longer emitters attained 100 GHz fT and fmax

Yukihiro Kiyota; Eiji Ohue; Takahiro Onai; Katsuyoshi Washio; Masamichi Tanabe; Taroh Inada

1996-01-01

106

Effects of ionizing radiation on small-signal microwave bipolar transistors  

Microsoft Academic Search

Microwave bipolar transistors are shown in this paper to be sensitive to high-energy electron andX-ray ionizing radiation at doses comparable to sensitive MOS devices. The most sensitive parameter is the dc current gain, hFE, which-in small-signal applications-leads to microwave performance sensitivity. Experimental results are presented for three device types which show that this radiation sensitivity can lead to severe device

I. Thomson

1978-01-01

107

Development of a planar heterojunction bipolar transistor for very high speed logic  

Microsoft Academic Search

The following describes the results of research on 3 to 5 molecular beam epitaxial (MBE) growth, material characterization and the fabrication of heterostructure bipolar transistors (HBT) for very-high-speed logic applications. Work on the InGaP\\/GaAs heterojunction (HJ) was completed. Isotype HJs were grown and evaluated by a CV reconstruction method in order to determine the energy band offsets. It was found

Stephen I. Long; Herbert Kroemer; M. A. Rao

1987-01-01

108

Development of a planar heterojunction bipolar transistor for very high speed logic  

Microsoft Academic Search

The following report describes the results of research on III-V molecular beam epitaxial (MBE) growth, material characterization and the fabrication of heterostructure bipolar transistors (HBT) for very high speed logic applications. During the reporting period work on the InGaP\\/GaAs heterojunction (HJ) was completed. Isotype HJs were grown and evaluated by a CV reconstruction method in order to determine the energy

S. I. Long; H. Kroemer; M. A. Rao

1986-01-01

109

Development of a planar heterojunction bipolar transistor for very high speed logic  

Microsoft Academic Search

The objective of this research project is to develop heterostructure bipolar transistors for very-high-speed logic. During the second year of effort, significant progress was made on (Al,Ga)As\\/GaAs HBTs of both emitter-down and emitter-up configurations, with current gains of 10 or greater being observed in both cases for base dopings which exceed emitter dopings. Structural modifications were evaluated which led to

S. I. Long

1984-01-01

110

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

111

DC and high-frequency performance of AlGaN\\/GaN Heterojunction Bipolar Transistors  

Microsoft Academic Search

The DC and high frequency performance of AlGaN\\/GaN Heterojunction Bipolar Transistors (HBTs) is analyzed using an enhanced drift-diffusion model and GaN\\/AlGaN material parameters, which were previously verified by modeling experimental device characteristics. The emitter–base diode turn-on voltage is as high as 2.7 V while the collector and base ideality factors are 1.16 and 1.46 respectively. A DC current gain of

Egor Alekseev; Dimitris Pavlidis

2000-01-01

112

High power operation of Pnp AlGaN\\/GaN heterojunction bipolar transistors  

Microsoft Academic Search

We fabricated a Pnp AlGaN\\/GaN heterojunction bipolar transistor and investigated its common - emitter current - voltage characteristics at room temperature. The device structures were grown by metalorganic vapor phase epitaxy on the sapphire substrates. The buffer layer was a newly developed Al2O3\\/AlN\\/AlON\\/Al2O3, resulting in the dislocation density of 6 × 108 cm-2 in MOVPE-grown GaN layer. This relatively low

K. Kumakura; Y. Yamauchi; T. Makimoto

2005-01-01

113

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

114

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

115

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

116

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

NASA Astrophysics Data System (ADS)

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 be attributed to charge transfer between two adjacent n+ regions. The dominant charge-collection process continues for 2.4 ns in n+-i-n+ isolation structures, but in n+-p-n+ isolation structures, it stops within 0.8 ns. The measured collected charge decreases as the isolation gap and background acceptor concentration increase. These experimental results can be explained semiquantitatively by the analytical model. This suggests that the primary mechanism of soft errors in GaAs ICs is a bipolar mechanism.

Umemoto, Yasunari; Matsunaga, Nobutoshi; Mitsusada, Kazumichi

1989-05-01

117

Effect of High-Voltage Heterojunction Bipolar Transistor Collector Design on f(T) and f(MAX)  

SciTech Connect

High-speed InGaP/GaAs heterojunction bipolar transistors (HBTs) for high-voltage circuit applications have been investigated. In order to obtain ideal IV characteristics, a lightly doped (N{sub DC} = 7.5 x 10{sup 15} cm{sup {minus}3}) thick (W{sub C} = 3.5 {micro}m) layer of GaAs was used as the collector layer. The devices fabricated have shown breakdown voltage exceeding 65 V. Device operated at up to a 60V bias, which is the highest operating voltage reported up to date for single heterojunction HBTs. Peak {line_integral}{sub T} and {line_integral}{sub MAX} values of 18 GHz and 29 GHz, respectively, have been achieved on a device with emitter area of 4x 12.5 {micro}m{sup 2}. Both {line_integral}{sub T} and {line_integral}{sub Max} degrades with higher bias, which is related to the elongation of the collector depletion width.

Ashby, C.I.H.; Baca, A.G.; Chang, P.C.; Hietala, V.M.

1999-03-02

118

An approximate HSPICE model for orbit low noise analog bipolar NPN transistors  

SciTech Connect

Vertical bipolar NPN transistors can be fabricated cheaply through MOSIS by using the Orbit 2 um Low Noise Analog CMOS process. The collector is formed from an N-well, the base from a p-base diffusion, and the emitter from an N-diffusion. However, since this is a CMOS process there is no buried layer in the collector. Therefore the collector resistance is quite large. Also, the minimum emitter size is 8 um {times} 8 um, which is substantially larger than many fast bipolar processes. For certain applications, though, such as common base or emitter follower amplifiers, the performance of this transistor may be quite acceptable. However, no AC SPICE model is published for this device. This paper describes a simple approximate measurement method that was used at Fermilab to formulate an HSPICE model for these transistor. This method requires only a fast pulse generator and a good digitizing oscilloscope with an active FET probe for the AC measurements. Model parameters for two transistors of different size are then given. 1 ref., 1 fig.

Zimmerman, T.

1991-07-01

119

Minority carrier lifetime degradation in carbon-doped base of InGaP/GaAs heterojunction bipolar transistors grown by low-pressure metalorganic chemical vapor deposition  

NASA Astrophysics Data System (ADS)

The effect of intermediate temperature annealing on the carbon-doped base region of InGaP/GaAs heterojunction bipolar transistors (HBTs) was studied. This work shows that the minority carrier lifetime in the samples doped at 5.5×1019 cm-3 decreases upon annealing at only 600 °C. Magnetotransport measurements were performed to obtain the minority carrier mobility, with which the minority carrier lifetime was extracted. The decrease in the direct current (dc) current gain upon annealing is attributed to the increase in the base bulk recombination. The correlation between the dc current gain and the magnetotransport measurements indicates that the annealing increases the carbon-related defects in the GaAs base, decreases the minority carrier lifetime in the carbon-doped base, and degrades the dc current gain of the InGaP/GaAs HBTs. These results are very important to the growth and postgrowth processing of InGaP/GaAs HBTs.

Yang, Q.; Scott, D. S.; Chung, T.; Stillman, G. E.

2000-07-01

120

Investigation and application of neutron damage to bipolar transistors in light water reactor dosimetry  

SciTech Connect

A method of fast neutron metrology and a basis for prediction of changes in performance parameters of semiconductor devices in power plant radiation environments has been established using Cf-252 sources. Three general purpose NPN bipolar transistors (PN2222A, ECG-196, and ECG-184) were chosen as the neutron damage monitors and the change in inverse d.c. current gain before and after irradiation was chosen as the damage parameter for the measurement. The main findings of the investigation were as follows: the change in inverse d.c. current gain for PN2222A transistors was approximately a linear function of the neutron fluence up to 2.0E15 n(1MeV)/cm/sup 2/. The concept of 1-MeV equivalent neutron fluence which characterizes an incident energy-fluence spectrum in terms of the fluence of monoenergetic neutrons at 1 MeV, is in error for application to common transistors in a typical power plant environment. Finally, the normalized damage coefficient which is the ratio of damage to 1-MeV equivalent neutron fluence divided by the measured base transit time of individual transistors, for all three types of transistors is nearly the same with an average value of 1.27E - 7 +/- 15.0% cm/sup 2//m(1 MeV).Sec.

Roknizadeh, M.

1987-01-01

121

Gallium arsenide metal-insulator-semiconductor field effect transistors (MISFET) with low temperature GaAs insulating layers  

Microsoft Academic Search

Metal-insulator-semiconductor field effect transistors (MISFETs) using low temperature (LT) GaAs as the insulator layer were fabricated and characterized. In this study, the influence of the AlAs spacer layer on MISFET properties is explored. Structures were grown with the thickness of the AlAs layer varied from 0 to 30 nm with the remainder of the total 60 nm insulator layer composed

C. A. Bozada; R. W. Dettmer; C. L. Eppers; K. Nakano; C. E. Stutz; R. E. Walline

1991-01-01

122

Importance of electron scattering with coupled plasmon-optical phonon modes in GaAs planar-doped barrier transistors  

Microsoft Academic Search

The GaAs planar-doped barrier (PDB) transistor is an MBE-grown structure which employs two unipolar homojunction barriers. One barrier, the emitter, injects energetic electrons into a thin n-type base region where these electrons are intended to experience negligible energy relaxation and thereby surmount the second (collector) barrier. Maximum common-base current gain or alpha values of 0.75 have been obtained at 77

M. A. Hollis; S. C. Palmateer; L. F. Eastman; N. V. Dandekar; P. M. Smith

1983-01-01

123

Importance of electron scattering with coupled plasmon-optical phonon modes in GaAs planar-doped barrier transistors  

Microsoft Academic Search

The GaAs planar-doped barrier (PDB) transistor is an MBE-grown structure which employs two unipolar homo junction barriers. One barrier, the emitter, injects energetic electrons into a thin n-type base region where these electrons are intended to experience negligible energy relaxation and thereby surmount the second (collector) barrier. Maximum common-base current gain or ? values of 0.75 have been obtained at

M. A. Hollis; S. C. Palmateer; L. F. Eastman; N. V. Dandekar; P. M. Smith

1983-01-01

124

Wide-band microwave amplifier realizations in microstrip employing a GaAs Schottky-barrier field-effect transistor  

Microsoft Academic Search

This work deals with the realization of two 4-8 GHz flat-gain amplifier designs in microstrip using a single GaAs Schottky-barrier field-effect transistor. Two aspects of microstrip amplifier realization are considered. The first aspect is accurate realization of required lumped and distributed circuit elements. The second involves detailed mathematical modelling of practical circuit elements, permitting computer analysis and optimization of complete

R. B. Watson Jr.

1976-01-01

125

Silicon Nitride Final Passivation for GaAs Metal Semi-Conductor Field Effect Transistors (MESFETs) Packaged in Plastic Mold  

Microsoft Academic Search

A highly reliable SiNx final passivation film for GaAs metal semi-conductor field effect transistor (MESFETs) packaged in plastic mold has been developed. The addition of He to N2 for the carrier gas in plasma enhanced chemical vapor deposition (PE-CVD) has been found effective to reduce both stress and pinholes and to significantly improve the resistance to moisture of the SiNx

Yoshihiro Saito; Yasuhiro Tosaka; Shigeru Nakajima

2003-01-01

126

Choice between FETs or Bipolar Transistors and Optimization of Their Working Points in Low Noise Preamplifiers for Fast Pulse Processing. Theory and Experimental Results  

Microsoft Academic Search

Theoretical and experimental investigation has been carried out to determine the best working conditions of single or parallel combinations of field-effect or bipolar transistors in low noise preamplifiers for processing times in the 10 ns range. The effects of diffusion capacitance and base spreading resistance in bipolar transistors have been put into evidence and a way of reducing the noise

E. Gatti; A. Hrisoho; P. F. Manfredi

1983-01-01

127

Reduction method for low-frequency noise of GaAs junction field-effect transistor at a cryogenic temperature  

NASA Astrophysics Data System (ADS)

A GaAs junction field-effect transistor (JFET) is a promising candidate for low-frequency, low-noise, and low-power cryogenic electronics to read out high-impedance photodetectors. We report on the spectral noise characteristics of a SONY n-type GaAs JFET, operating at the depression mode, at a cryogenic temperature of 4.2 K. If the GaAs JFET is turned on at 4.2 K, a random telegraph signal (RTS) is found to be the dominant noise source at low frequencies. However, the switching rate of RTS can be drastically reduced if the GaAs JFET is heated up to 55 K and cooled down again to 4.2 K while keeping the same drain current flow. We refer to this phenomenon as the thermal cure (TC). With TC, low-frequency noise can be reduced to below 1 ?V/Hz1/2 at 1 Hz. The critical temperature for TC is found to be ~35 K for our GaAs JFET.

Fujiwara, M.; Sasaki, M.; Akiba, M.

2002-03-01

128

Anomalous dose rate effects in gamma irradiated SiGe heterojunction bipolar transistors  

SciTech Connect

Low dose rate (LDR) cobalt-60 (0.1 rad(Si)/s) gamma irradiated Silicon Germanium (SiGe) Heterojunction Bipolar Transistors (HBTs) were studied. Comparisons were made with devices irradiated with 300 rad(Si)/s gamma radiation to verify if LDR radiation is a serious radiation hardness assurance (RHA) issue. Almost no LDR degradation was observed in this technology up to 50 krad(Si). The assumption of the presence of two competing mechanisms is justified by experimental results. At low total dose ({le}20 krad), an anomalous base current decrease was observed which is attributed to self-annealing of deep-level traps to shallower levels. An increase in base current at larger total doses is attributed to radiation induced generation-recombination (G/R) center generation. Experiments on gate-assisted lateral PNP transistors and 2D numerical simulations using MEDICI were used to confirm these assertions.

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

1999-12-01

129

Electrostatic discharge characterization of epitaxial-base silicon-germanium heterojunction bipolar transistors  

Microsoft Academic Search

This paper investigates high-current and electrostatic discharge (ESD) phenomena in pseudomorphic epitaxial-base silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) in base-collector, base-emitter, collector-emitter and collector-to-substrate configurations. Transmission line pulse (TLP) and ESD human body model (HBM) wafer-level reliability testing of SiGe HBTs is completed for high-current characterization and evaluation of the ESD robustness of a BiCMOS SiGe technology

S. Voldman; P. Juliano; J. Schmidt; R. Johnson; L. Lanzerotti; A. Joseph; C. Brennan; J. Dunn; D. Harame; E. Rosenbaum; B. Meyerson

2000-01-01

130

Measurement of dose rate dependence of radiation induced damage to the current gain in bipolar transistors  

SciTech Connect

The authors report the study of radiation induced change in the current gain of bipolar transistors for three different gamma dose rates. The dose rates differed by a factor of 60 with the lowest close to that anticipated for the LHC, and the highest at a rate they have been routinely using for radiation damage tests. The maximum dose attained was 200kRad, which is high enough to compare with other measurements. The importance of annealing high dose rate data is demonstrated.

Dorfan, D.; Dubbs, T.; Grillo, A.A. [and others

1999-12-01

131

Contactless electroreflectance characterization of GaInP/GaAs heterojunction bipolar transistor structures  

NASA Astrophysics Data System (ADS)

We have characterized two GaInP/GaAs (001) heterojunction bipolar transistor structures, fabricated by organometallic chemical vapor deposition and chemical beam epitaxy, using contactless electroreflectance, including the dependence of the signals on the polarization {[110] and [110]} of the incident radiation. The ordering parameters deduced from the polarization dependence of the GaInP emitter signals are consistent with transmission electron microscope measurements. From the observed Franz-Keldysh oscillations we have evaluated the electric fields in the collector/base and emitter/base regions. In general, these fields are in good agreement with a calculation based on a comprehensive, self-consistent model, including the photovoltaic effect.

Huang, Y. S.; Sun, W. D.; Pollak, Fred H.; Freeouf, J. L.; Calder, I. D.; Mallard, R. E.

1998-07-01

132

Wafer-fused AlGaAs/GaAs/GaN heterojunction bipolar transistor  

NASA Astrophysics Data System (ADS)

We describe an n-AlGaAs/p-GaAs/n-GaN heterojunction bipolar transistor, formed via wafer fusion of a p-GaAs base to an n-GaN collector. Wafer fusion was carried out at 750 °C for 1 h. Devices utilized a thick base (0.15 ?m) and exhibited limited common-emitter current gain (0.2-0.5) at an output current density of ~100 A/cm2. Devices were operated to VCE greater than 20 V, with a low VCE offset (1 V). Improvements in both device structure and wafer fusion conditions should provide further improvements in device performance.

Estrada, Sarah; Xing, Huili; Stonas, Andreas; Huntington, Andrew; Mishra, Umesh; Denbaars, Steven; Coldren, Larry; Hu, Evelyn

2003-02-01

133

Influence of electron irradiation on the switching speed in insulated gate bipolar transistors  

NASA Astrophysics Data System (ADS)

The influence of electron irradiation on the switching speed in insulated gate bipolar transistors (IGBT) with different epitaxial layer thicknesses is discussed in detail. The experimental results prove that the fall time of IGBT increases when increasing the thickness of the epitaxial layer. However, there is no obvious difference between the ratios of the fall time after irradiation to those before irradiation for different epitaxial layer thicknesses. The increase in switching speed of the IGBT is accompanied by an increase in the forward drop, and a trade-off curve between forward voltage drop and fall time of IGBT is presented.

Shuojin, Lu; Lixin, Wang; Jiang, Lu; Gang, Liu; Zhengsheng, Han

2009-06-01

134

A>400 GHz fmax transferred-substrate heterojunction bipolar transistor IC technology  

Microsoft Academic Search

We report transferred-substrate AlInAs\\/GaInAs bipolar transistors. A device having a 0.6 ?m×25 ?m emitter and a 0.8 ?m×29 ?m collector exhibited f?=134 GHz and f max>400 GHz. A device with a 0.6 ?m×25 ?m emitter and a 1.8 ?m×29 ?m collector exhibited 400 GHz fmax 164 GHz f?. The improvement in fmax over previous transferred-substrate HBT's is due to improved

Q. Lee; B. Agarwal; D. Mensa; R. Pullela; J. Guthrie; L. Samoska; M. J. W. Rodwell

1998-01-01

135

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

136

Reliability of GaAs Metal-Semiconductor Field Effect Transistors Grown on Si Substrates  

NASA Astrophysics Data System (ADS)

We report on the reliability of metal-semiconductor field effect transistors (MESFETs) fabricated on GaAs/Si compared to that of MESFETs on GaAs/GaAs, based on the results of the high-temperature storage test under dc bias. The failure mode was the non-pinch-off phenomenon with the increase in drain current for both types of MESFETs. From the results of observation using a scanning electron microscope and Auger electron analysis, gate metal dispersion and the possibility of a reaction between the metal and the GaAs channel were revealed for the failed devices. The mean time to failure for the MESFETs/Si at a channel temperature of 130°C was predicted to be 1.28×106 h from the storage test, which was almost equal to that for MESFETs/GaAs. This result indicates that the lifetime of MESFETs/Si is comparable to that of MESFETs/GaAs, and the high density of dislocations in the GaAs/Si does not affect the reliability of the devices.

Aigo, Takashi; Takayama, Seiji; Yabe, Aiji; Tachikawa, Akiyoshi; Moritani, Akihiro

1998-06-01

137

GaAs/Al/sub 0. 3/Ga/sub 0. 7/As, heterojunction bipolar transistors for high-temperature (T > 300/sup 0/C), power electronic applications  

SciTech Connect

Solid-state devices formed from compound semiconductor materials like GaAs, GaP, SiC, and (Al,Ga)As have long been viewed as candidates for use in electronic circuits functioning at temperatures greater than 300/sup 0/C. To address the specific needs of power semiconductor devices operating simultaneously at high currents, voltages, and high temperatures, heterojunction devices formed from combinations of GaAs and (Al,Ga)As have recently been proposed. These novel heterojunction structures display reduced resistive and voltage parasitics when compared to wide-bandgap GaP or SiC, homojunction diodes without seriously compromising control of thermally generated leakage currents. In this study, a prototype, low-power, (Al,Ga)As/GaAs, heterojunction bipolar transistor (HBT) is described which has demonstrated excellent electrical characteristics in the 300 to 400/sup 0/C temperature range. At 350/sup 0/C, the HBT has a common-emitter current gain of 14 (V/sub CE/ = 5V, I/sub C/ = 10 mA) and collector-base leakage of 6.4 x 10/sup -2/ A/cm/sup 2/ (V/sub CB/ = 5 V).

Zipperian, T.E.; Brennan, T.M.; Hammons, B.E.

1987-01-01

138

A 55-GHz-Small-Signal-Bandwidth Switched Emitter Follower in InP Heterojunction Bipolar Transistors  

NASA Astrophysics Data System (ADS)

Two Switched Emitter Follower circuits are designed and fabricated with a 320 GHz-Ft-InP Double Heterojunction Bipolar Transistors process (DHBT). The first one uses a 10?m emitter length (T10) transistors and the second a 7?m emitter length (T7) transistors. Measurements show a-3dB small signal bandwidth up to 55GHz with a sufficient isolation larger than 30dB. An extensive analysis as function of sizes, hold capacitor and bias conditions were performed by simulations in order to obtain a good tradeoff between bandwidth, isolation and linearity.

Deza, Julien; Ouslimani, Achour; Konczykowska, Agnieszka; Kasbari, Abed-Elhak; Godin, Jean; Pailler, Gwennolé

139

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

PubMed

In this study, a urea biosensor was prepared by the immobilization of urease onto the sensitive membrane of an extended-base bipolar junction transistor. The pH variation was used to detect the concentration of urea. The SnO2/ITO glass, fabricated by sputtering SnO2 on the conductive ITO glass, was used as a pH-sensitive membrane, which was connected with a commercial bipolar junction transistor device. The gels, fabricated by the poly vinyl alcohol with pendent styrylpyridinium groups, were used to immobilize the urease. This readout circuit, fabricated in a 0.35-um CMOS 2P4M process, operated at 3.3V supply voltage. This circuit occupied an area of 1.0 mm × 0.9 mm. The dynamic range of the urea biosensor was from 1.4 to 64 mg/dl at the 10 mM phosphate buffer solution and the sensitivity of this range was about 65.8 mV/pUrea. The effect of urea biosensors with different pH values was considered, and the characteristics of urea biosensors based on EBBJT were described. PMID:24092129

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

2013-01-01

140

Study of Radiation (neutron, ?-RAY, and Carbon-Iron Effects on Npn Bipolar Transistors  

NASA Astrophysics Data System (ADS)

Integrated microscopic investigations of bipolar junction damages in silicon detectors following neutron irradiation and studies of the degradation of the performance of bipolar transistors, due to generation of defects in silicon irradiated with neutron and ion carbons, were performed. The integrated microscopic investigations were studied by means of an advanced contact potential difference (CPD) method in atomic force microscopy (AFM). It was shown that gain degradation appears and that the density of generated defects is the same for neutron and carbon irradiation, but the density of created Frenkel pairs (interstitial-vacancy) is smaller for neutrons than for carbon ions. The value of ?(1/?) of the transistor was evaluated from the density of Frenkel pairs (CF), for given value of ?. The dependence of ?(1/?) on concentration of CF for lateral and vertical pnp juntions at Ic=1?m, was shown. Fron the data of density of Frenkel pairs as a function of ratio ? (R), was obtained, R=CF/?. Ratio R was independent on ?, for a given type of irradiation (neutrons or carbon ions). For carbon ions, R depends on the value of the energy of incident particles (medium energy 11.1 MeV/a and high energy 95.0 MeV/a of the carbon ions.

Colder, A.; Levalois, M.; Marie, P.; Croitoru, N.; D'Angelo, P.; de Marchi, M.; Marcolongo, S.; Rancoita, P. G.; Seidman, A.; Fallica, G.; Leonardi, S.; Modica, R.

2002-11-01

141

Irradiation effects of 25 MeV silicon ions on SiGe heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

Silicon–germanium (SiGe) heterojunction bipolar transistors (HBTs) were exposed to 25 MeV Si4+ ion with equivalent absorbed dose from 200 krad(Si) to 10 Mrad(Si). The transistor characteristics such as forward Gummel, reverse Gummel, leakage current of base–emitter (BE) junction and base–collector (BC) junction were studied before and after irradiation and were used to quantify the dose tolerance to the swift heavy ion irradiation. The base current was found more sensitive than collector current and current gain appeared to decline with the ion fluence increasing. On the reverse Gummel characteristics, besides the degradation in the base current, an unexpected increase in emitter current was observed with the ion fluence increasing. The output characteristics of the irradiated SiGe HBTs exhibited a decrease in the collector current with the increasing ion fluence. The reverse leakage current of BE and BC junctions increased with the increase in ion fluence. The self-annealing effect at room temperature was found less influence on the performance degradation. The displacement damages in the transistor were found to dominate the performance degradation of SiGe HBT after 25 MeV Si4+ ion irradiation.

Sun, YaBin; Fu, Jun; Xu, Jun; Wang, YuDong; Zhou, Wei; Zhang, Wei; Cui, Jie; Li, GaoQing; Liu, ZhiHong

2013-10-01

142

Carrier stored trench-gate bipolar transistor (CSTBT)-a novel power device for high voltage application  

Microsoft Academic Search

A new device concept, called the Carrier Stored Trench-Gate Bipolar Transistor (CSTBT) is reported for the first time. The CSTBT forms the n layer under p base between trenches, the n layer stores carriers; as aesult, the carrier distribution of the CSTBT becomes that of the diode. We examined the performance of the CSTBT by simulation and experiment in the

H. Takahashi; H. Haruguchi; H. Hagino; T. Yamada

1996-01-01

143

Gain limitations of scaled InP/InGaAs heterojunction bipolar transistors  

SciTech Connect

We investigate a current gain degradation mechanism in self-aligned InP/InGaAs heterojunction bipolar transistors. We show that surface level pinning at the emitter sidewall gives rise to a peripheral emitter injection current into the base which increases the base current due to electrons recombining at the base contacts. The surface charge at the extrinsic base surface causes the formation of a conducting channel which further enhances the electron flow from the emitter to the base contacts. Two-dimensional numerical simulations of the emitter region combined with Monte-Carlo simulations of the injection process at the abrupt base-emitter heterojunction are in good agreement with the measurements. This effect will be especially severe for submicron emitter widths where the emitter perimeter to emitter area ratio is large. {copyright} 2001 American Institute of Physics.

Rohner, M.; Schnyder, I.; Huber, D.; Jackel, H.; Bergamaschi, C.

2001-06-01

144

Bipolar-unipolar transition in thermospin transport through a graphene-based transistor  

NASA Astrophysics Data System (ADS)

Based on the mean-field Hubbard model, we study the thermally driven spin-polarized transport through a local-gated magnetic zigzag graphene nanoribbon by using the nonequilibrium Green's function method. The spin currents are tuned by the source temperature, the temperature bias, and the gate voltage. We find this transistor exhibits a transition from the bipolar to unipolar spin transport under associated modulations of thermal bias and gate voltage. It is argued that the result originates from the band selective rule related to parity conservation of wave functions in quantum tunneling. We also find the thermal magnetoresistance of the ribbon between the ferromagnetic excited state and antiferromagnetic ground state could reach up to 105% under a small local gate voltage. This proposed device provides possibility for bettering control of the spin freedom of electrons in graphene materials.

Zhao, Zhiyun; Zhai, Xuechao; Jin, Guojun

2012-08-01

145

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

146

SEMICONDUCTOR DEVICES: Carrier stored trench-gate bipolar transistor with p-floating layer  

NASA Astrophysics Data System (ADS)

A carrier stored trench-gate bipolar transistor (CSTBT) with a p-floating layer (PF-CSTBT) is proposed. Due to the p-floating layer, the thick and highly doped carrier stored layer can be induced, and the conductivity modulation effect will be enhanced near the emitter. The accumulation resistance and the spreading resistance are reduced. The on-state loss will be much lower than in a conventional CSTBT. With the p-floating layer, the distribution of electric fields of the conventional IGBT is reformed, and the breakdown voltage is remarkably improved. The simulation results have shown that the forward voltage drop (VCE-on) of the novel structure is reduced by 20% and 17% respectively, compared with the conventional trench IGBT (TIGBT) and CSTBT under the same conditions. Moreover, an increment of more than 100 V of the breakdown voltage is achieved without sacrificing the SCSOA (short circuit safely operation area) compared with the conventional TIGBT.

Rongyao, Ma; Zehong, Li; Xin, Hong; Bo, Zhang

2010-02-01

147

SEMICONDUCTOR INTEGRATED CIRCUITS: Insulated gate bipolar transistor with trench gate structure of accumulation channel  

NASA Astrophysics Data System (ADS)

An accumulation channel trench gate insulated gate bipolar transistor (ACT-IGBT) is proposed. The simulation results show that for a blocking capability of 1200 V, the on-state voltage drops of ACT-IGBT are 1.5 and 2 V at a temperature of 300 and 400 K, respectively, at a collector current density of 100 A/cm2. In contrast, the on-state voltage drops of a conventional trench gate IGBT (CT-IGBT) are 1.7 and 2.4 V at a temperature of 300 and 400 K, respectively. Compared to the CT-IGBT, the ACT-IGBT has a lower on-state voltage drop and a larger forward bias safe operating area. Meanwhile, the forward blocking characteristics and turn-off performance of the ACT-IGBT are also analyzed.

Mengliang, Qian; Zehong, Li; Bo, Zhang; Zhaoji, Li

2010-03-01

148

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

149

GaN pnp bipolar junction transistors operated to 250 C  

SciTech Connect

The authors report on the dc performance of the first GaN pnp bipolar junction transistor. The structure was grown by MOCVD on c-plane sapphire substrates and mesas formed by low damage Inductively Coupled Plasma etching with a Cl{sub 2}/Ar chemistry. The dc characteristics were measured up to V{sub BC} of 65 V in common base mode and at temperatures up to 250 C. Under all conditions, I{sub C} {approximately} I{sub E}, indicating higher emitter injection efficiency. The offset voltage was {le} 2 V and devices were operated up to power densities of 40kW{center{underscore}dot}cm{sup {minus}2}.

Zhang, A.P.; Dang, G.; Ren, F.; Han, J.; Monier, C.; Baca, A.G.; Cao, X.A.; Cho, H.; Abernathy, C.R.; Pearton, S.J.

2000-01-03

150

Microwave performance of a self-aligned GaInP/Ga heterojunction bipolar transistor  

SciTech Connect

Microwave performance of a self-aligned GaInP/GaAs heterojunction bipolar transistor (HBT) is presented. At an operating current density of 2.08 [times] 10[sup 4] A/cm[sup 2], the measured cutoff frequency is 50 GHz, and the maximum oscillation frequency extrapolated from measured unilateral gain and the maximum available gain are 116 and 81 GHz, respectively, all using 20-dB/decade slopes. To the author's knowledge, these represent the highest reported values of HBT's based on the GaInP/GaAs material system. These results are compared with other reported high-frequency performance of GaInP HBT's. In addition, these results are compared with AlGaAs/GaAs HBT's having a similar device structure.

Liu, W.; Fan, Shoukong; Henderson, T. (Texas Instruments Inc., Dallas (United States)); Davito, D. (Epitronics Corp., Phoenix, AZ (United States))

1993-04-01

151

InGaAs/InP heterojunction bipolar transistors for ultra-low power circuit applications  

SciTech Connect

For many modern day portable electronic applications, low power high speed devices have become very desirable. Very high values of f{sub T} and f{sub MAX} have been reported with InGaAs/InP heterojunction bipolar transistors (HBTs), but only under high bias and high current level operating conditions. An InGaAs/InP ultra-lowpower HBT with f{sub MAX} greater than 10 GHz operating at less than 20 {micro}A has been reported for the first time in this work. The results are obtained on a 2.5 x 5 {micro}m{sup 2} device, corresponding to less than 150 A/cm{sup 2} of current density. These are the lowest current levels at which f{sub MAX} {ge} 10 GHz has been reported.

Chang, P.C.; Baca, A.G.; Hafich, M.J.; Ashby, C.I.

1998-08-01

152

Transistor Design Considerations for Low-Noise Preamplifiers  

Microsoft Academic Search

A review is presented of design considerations for GaAs Schottky-barrier FETs and other types of transistors in low-noise amplifiers for capacitive sources which are used in nuclear radiation detectors and high speed fiber-optic communication systems. Ultimate limits on performance are evaluated in terms of the gm\\/Ci ratio and the gate leakage current to minimize the noise sources. Si bipolar transistors

R. B. Fair

1976-01-01

153

Investigation of the Effect of Graded Layers and Tunneling on the Performance of AlGaAs/GaAs Heterojunction Bipolar Transistors.  

National Technical Information Service (NTIS)

We present the results of theoretical and experimental studies of the heterojunction bipolar transistor. Our calculations are based on a new thermionic field-diffusion model which takes into account the dependence of the emitter efficiency on the height o...

A. A. Grinberg M. S. Shur R. J. Fischer H. Morkoc

1984-01-01

154

Influence of Pseudomorphic Base-Emitter Spacer Layers on Current-Induced Degradation of Beryllium-Doped InGaAs/InAlAs Heterojunction Bipolar Transistors.  

National Technical Information Service (NTIS)

We present in this paper a basis for the design of high performance heterojunction bipolar transistors in which base dopant diffusion can be drastically reduced, or even eliminated. From previous theoretical and experimental studies we have established th...

K. Zhang X. Zhang P. Bhattacharya J. Singh

1996-01-01

155

Comparative Study of GaInP/GaAs Heterojunction Bipolar Transistors Grown by CBE Using TBA/TBP and AsH3/PH3 Sources.  

National Technical Information Service (NTIS)

GaInP/GaAs Heterojunction Bipolar Transistors (HBT's) have been fabricated on epitaxial layers grown by Chemical Beam Epitaxy (CBE) using an all metalorganic approach. Reduced toxicity tertiarybutylarsine (TBA) and tertiarybutylphosphine (TBP) were used f...

G. I. Ng D. Pavlidis A. Samelis D. Pehlke J. C. Garcia

1994-01-01

156

Enhanced Low Dose Rate Sensitivity (ELDRS) tests on advanced SiGe bipolar transistors for very high total dose applications  

NASA Astrophysics Data System (ADS)

A new comprehensive method for assessing Enhanced Low Dose Rate Sensitivity (ELDRS) in bipolar transistors to be used for very high total doses is applied to an advanced SiGe HBT technology for its use in the ATLAS Upgrade at CERN. Conventional ELDRS assessment methods are combined with switched experiments (high/low dose rate), providing a way to verify the presence of ELDRS at very high doses in reasonable irradiation time. Additionally, an anomalous damage recovery has been found in transistors with saturated damage after further low dose rate irradiations.

Ullán, M.; Wilder, M.; Spieler, H.; Spencer, E.; Rescia, S.; Newcomer, F. M.; Martinez-McKinney, F.; Kononenko, W.; Grillo, A. A.; Díez, S.

2013-10-01

157

Depletion-mode GaAs metal-oxide-semiconductor field-effect transistor with HfO2 dielectric and germanium interfacial passivation layer  

NASA Astrophysics Data System (ADS)

The authors present depletion-mode n-channel GaAs metal-oxide-semiconductor field-effect transistor (MOSFET) with a TaN gate electrode, a thin HfO2 gate dielectric, and a thin germanium (Ge) interfacial passivation layer (IPL). Depletion-mode MOSFET on the molecular-beam epitaxy-grown n-type GaAs layer with an equivalent oxide thickness of 17 A? exhibits excellent transistor output characteristics such as a maximum transconductance of 176 mS/mm and a maximum effective electron mobility of 970 cm2/V s. MOSFET shows a surface accumulation channel conduction above flatband condition, indicating that a high quality interface can be achieved using a Ge IPL on GaAs substrate.

Kim, Hyoung-Sub; Ok, Injo; Zhang, Manhong; Lee, T.; Zhu, F.; Yu, L.; Lee, Jack C.; Koveshnikov, S.; Tsai, W.; Tokranov, V.; Yakimov, M.; Oktyabrsky, S.

2006-11-01

158

Metod opredeleniya raspredelennogo soprotivleniya bazy bipolyarnykh tranzistorov pri pomoshchi izmereniya shuma strobiruemym integratorom. (Determining distributed base resistance of bipolar transistors by noise measurements with gated integrator).  

National Technical Information Service (NTIS)

Small value of distributed base resistance r is one of the demands for a head bipolar transistor of a low noise preamplifier. Thus, the choice of transistor type (since typical values of r are not specified in reference books) and specimen rejection requi...

A. V. Korytov

1989-01-01

159

Measurement of low-frequency base and collector current noise and coherence in SiGe heterojunction bipolar transistors using transimpedance amplifiers  

Microsoft Academic Search

Transimpedance amplifiers have been used for direct study of current noise in silicon germanium (SiGe) heterojunction bipolar transistors (HBT's) at different biasing conditions. This has facilitated a wider range of resistances in the measurement circuit around the transistor than is possible when using a voltage amplifier for the same kind of measurements. The ac current amplification factor h fe and

Staffan P. O. Bruce; L. K. J. Vandamme; Anders Rydberg

1999-01-01

160

Investigation and Application of Neutron Damage to Bipolar Transistors in Light Water Reactor Dosimetry.  

NASA Astrophysics Data System (ADS)

A method of fast neutron metrology and a basis for prediction of changes in performance parameters of semiconductor devices in power plant radiation environments has been established using Cf-252 sources. Three general purpose NPN bipolar transistors (PN2222A, ECG-196, and ECG-184) were chosen as the neutron damage monitors and the change in inverse d.c. current gain before and after irradiation was chosen as the damage parameter for the measurement. The ECG-196 and ECG-184 transistors have been calibrated for neutron fluences ranging from 1.0E10 n(1MeV)/ {rm cm}^2 to 1.0E12 n(1MeV)/{rm cm}^2. PN2222A transistors have been calibrated for neutron fluences ranging from 1.0E12 to 2.0E15 n(1MeV)/cm^2 . The main findings of the investigation were as follows:. The change in inverse d.c. current gain for PN2222A transistors was approximately a linear function of the neutron fluence up to 2.0E15 n(1MeV)/{rm cm}^2. The departure from linearity has been represented by a quadratic function. The concept of 1-MeV equivalent neutron fluence which characterizes an incident energy-fluence spectrum in terms of the fluence of monoenergetic neutrons at 1 MeV, is in error for application to common transistors in a typical power plant environment. This has been proven to be due to the fact that low energy neutron effects are not correctly accounted for when using the silicon displacement kerma to calculate 1-MeV equivalent neutron fluence. Therefore, a model has been developed by which the damage response is corrected in order to account for the low energy neutron effects. The normalized damage coefficient which is the ratio of damage to 1-MeV equivalent neutron fluence divided by the measured base transit time of individual transistors, for all three types of transistors is nearly the same with an average value of 1.27E - 7 +/- 15.0% {rm cm}^2 /m(1MeV).Sec. This supports the theory that base transit time is a parameter from which the neutron vulnerability in a nuclear radiation environment can be determined. The developed techniques have been used in five reactor dosimetry experiments. Four of these experiments were conducted at reactor buildings of Unit-I and Unit-II of the Arkansas Nuclear One power plant. Another experiment was performed at the nuclear reactor laboratory of University of Illinois. In these experiments, the 1-MeV equivalent fluence rates for several irradiation positions have been calculated.

Roknizadeh, Mansour

161

ESD (Electrostatic Discharge)/EOS (Electrical OverStress) susceptibility of a class of bipolar RF power transistors: Experimental studies on stripline-opposed emitter transistors  

NASA Astrophysics Data System (ADS)

Susceptibility of a class of bipolar RF power transistors (stripline-opposed emitter (SOE) devices) to electrical overstressing (EOS) is studied. Having unique packaging compatible for RF/stripline applications, SOE devices pose prominent/extended exteriors for static propensity and hence are critically vulnerable to degradation as predictable by the charge-device modeling. As such, contrary to the popular notion that rugged bipolar devices are not excessively prone to ESD-based detrimental effects, SOE transistors, on the other hand, are severely vulnerable. It is not just the Wunsch Bell limit of catastrophy due to PN junction burnout (under high-level zaps) that dictates the damages in the devices like SOE transistors. The entire device configuration, i.e., active junction, metallization, bonding, etc., as well as the external packaging, decide the device lethality. This is demonstrated by experimental studies on a family of SOE devices by subjecting them to ESD zaps using a Human Body Simulator. The results positively indicate that their vulnerability is in excess of Class II limit and require specific handling precautions, lest they pose quality control and/or field failure problems. Especially, considering these devices being extremely costly, specific ESD control efforts are rather imminent.

Neelakantaswamy, Perambur S.; Turkman, Ibrahim R.

1986-12-01

162

An Analytical Model of SiGe Heterojunction Bipolar Transistors on SOI Substrate for Large Current Situations  

NASA Astrophysics Data System (ADS)

The large current effect of silicon germanium heterojunction bipolar transistors fabricated on thin silicon-on-insulator is included in the model. As the current is two-dimensional, the injection for large current is vertical plus horizontal and is quite different from that of the bulk device. Critical parameters modeling the large current, such as the collector injection width, the hole density and the corresponding potential in the injection region, are discussed, and the influence to the transit time is also analyzed.

Xu, Xiao-Bo; Zhang, Bin; Yang, Yin-Tang; Li, Yue-Jin

2013-02-01

163

Dramatic enhancement in the gain of a GaAs/AlGaAs heterostructure bipolar transistor by surface chemical passivation  

NASA Astrophysics Data System (ADS)

With a simple chemical treatment nonradiative recombination centers at the periphery of a GaAs/AlGaAs heterostructure bipolar transistor were passivated, resulting in a 60-fold increase in the current gain of the device at low collector currents. This large enhancement in gain was achieved by spin coating thin films of Na2S(9H2O) onto the devices after their fabrication. The passivation mechanism and the implications for other III-V optoelectronic devices are discussed.

Sandroff, C. J.; Nottenburg, R. N.; Bischoff, J.-C.; Bhat, R.

1987-07-01

164

40 GHz transimpedance amplifier with differential outputs using InP\\/InGaAs heterojunction bipolar transistors  

Microsoft Academic Search

High gain and bandwidth transimpedance amplifiers (TIA) are required for fiber optic receiver modules. This paper reports on the design, fabrication and characterization of a 40 Gbit\\/s TIA for SONET\\/SDH STS-768\\/STM-256 applications based on an InP\\/InGaAs single heterojunction bipolar transistor (SHBT) process developed at Vitesse Semiconductor Corporation (Vitesse Indium Phosphide Release 1 or VIP-1). This amplifier consists of a single-ended

Charles Q. Wu; Emilio A. Sovero; Bruce Massey

2002-01-01

165

Electrostatic discharge and high current pulse characterization of epitaxial-base silicon-germanium heterojunction bipolar transistors  

Microsoft Academic Search

This paper investigates high-current and electrostatic discharge (ESD) phenomenon in pseudomorphic epitaxial-base silicon-germanium (SiGe) heterojunction bipolar transistors (HBT). Transmission line pulse (TLP) and ESD human body model (HBM) wafer-level reliability testing, failure analysis and simulation of SiGe HBT devices is completed for high-current characterization and evaluation of the ESD robustness of a BiCMOS SiGe technology

S. Voldman; P. Juliano; R. Johnson; N. Schmidt; A. Joseph; S. Furkay; E. Rosenbaum; J. Dunn; D. Harame; B. Meyerson

2000-01-01

166

Novel process for emitter-base-collector self-aligned heterojunction bipolar transistor using a pattern-inversion method  

NASA Astrophysics Data System (ADS)

This letter describes a novel fabrication technique for an emitter-base-collector self-aligned heterojunction bipolar transistor using a pattern-inversion method. This technique allows the emitter contact to be formed after base contacting, leading to a small feature size device. Reactive-ion-beam etching is employed instead of total wet etching to obtain small base contact size. The emitter contact size is 15 sq microns and the base contact size is 20 sq microns.

Tanaka, S.; Madihian, M.; Toyoshima, H.; Hayama, N.; Honjo, K.

1987-05-01

167

Root-Cause Analysis and Statistical Process Control of Epilayers for SiGe:C HeteroStructure Bipolar Transistors  

Microsoft Academic Search

The SiGe:C hetero-structure bipolar transistor (HBT) has turned into a key technology for wireless communication. This paper describes various critical analytical techniques to bring up and maintain the SiGe:C epi-process. Two types of analysis are critical, (1) routine monitoring SiGe base and Si cap thickness, doping dose, Ge composition profile, and their uniformity across the wafer; and (2) root-cause analysis

Qianghua Xie; Erika Duda; Mike Kottke; Wentao Qin; Xiangdong Wang; Shifeng Lu; Martha Erickson; Heather Kretzschmar; Linda Cross; Sharon Murphy

2003-01-01

168

Very high-power-density CW operation of GaAs\\/AlGaAs microwave heterojunction bipolar transistors  

Microsoft Academic Search

Thermal instability of multi-emitter high-power microwave heterojunction bipolar transistors (HBTs) was eliminated using a novel heat spreading technique that regulates internal device currents to avoid the formation of hot spots. Devices with 2- and 3-?m minimum emitter sizes and no intentional ballast resistors showed unconditionally stable CW operation up to the device electronic limitations. A record 10-mW\\/?m2 power density was

Burhan Bayraktaroglu; J. Barrette; L. Kehias; Chern I. Huang; R. Fitch; R. Neidhard; R. Scherer

1993-01-01

169

Diffusion-Induced Degradation of AlGaAs\\/GaAs Heterojunction Bipolar Transistors by Thermal Stress  

Microsoft Academic Search

Two-dimensional simulations of the impact of beryllium diffusion at the junction interface of AlGaAs\\/GaAs heterojunction bipolar transistors (HBTs) on the device performance are reported. It is shown that the current driving capability is greatly influenced by the redistributed profile of beryllium at the emitter-base junction due to outdiffusion. In addition, the dependence of the RF characteristics on the Be outdiffusion

Sungmo Hong; Jumin Kim; Jaejin Lee; Taeyoung Won

1993-01-01

170

A 6GHz integrated phase-locked loop using AlGaAs\\/GaAs heterojunction bipolar transistors  

Microsoft Academic Search

A fully integrated 6-GHz phase-locked-loop (PLL) fabricated using AlGaAs\\/GaAs heterojunction bipolar transistors (HBTs) is described. The PLL is intended for use in multigigabit-per-second clock recovery circuits for fiber-optic communication systems. The PLL circuit consists of a frequency quadrupling ring voltage-controlled oscillator (VCO), a balanced phase detector, and a lag-lead loop filter. The closed-loop bandwidth is approximately 150 MHz. The tracking

Aaron W. Buchwald; Kenneth W. Martin; Aaron K. Oki; Kevin W. Kobayashi

1992-01-01

171

Double heterojunction GaAs-GaAlAs bipolar transistors grown by MOCVD for emitter coupled logic circuits  

Microsoft Academic Search

Double heterojonction N-p-N GaAlAs-GaAs-GaAlAs bipolar transistors (DHBT's) have been developed using MOCVD growth. We have investigated the influence of growth conditions on the d.c. characteristics of DHBT's. Devices with 0.2 ľm base thichness and p = 2.1018cm-3exihibited common emitter current gain, ?, of up to 5500. The recombination current has been reduced such asbeta simeq 1for current densites as low

C. Dubon; R. Azoulay; P. Desrousseaux; J. Dangla; A. M. Duchenois; M. Hountondji; D. Ankri

1983-01-01

172

High-linearity, low DC power monolithic GaAs HBT broadband amplifiers to 11 GHz  

Microsoft Academic Search

Two broadband monolithic amplifiers based on GaAs heterojunction bipolar transistors (HBT) have been developed covering the 0.05-11-GHz frequency band. The hybrid designs reported by B.L. Nelson et al. (1989 IEEE GaAs IC Symp. Digest, Oct. 1989, p.79-82) have been successfully implemented with monolithic microwave IC (MMIC) technology. These amplifiers are the first reported balanced and distributed MMIC HBT amplifiers and

B. L. Nelson; D. K. Umemoto; C. B. Perry; R. Dixit; B. R. Allen; M. E. Kim; A. K. Oki

1990-01-01

173

Halogen-containing compounds in solid source III-V molecular beam epitaxy, and their use for fabrication of high performance heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

The theme of this dissertation is the improvement of III-V compound semiconductor heterojunction bipolar transistors (HBT's) through the use of iodine or bromine in molecular beam epitaxy (MBE). The motivation for this work is to increase the speed of AlGaAs/GaAs HBT's by reduction of base resistance and parasitic base-collector capacitance. The base resistance of an HBT can be minimized, without severely affecting the base transit time, by doping the base to the highest attainable level. It is demonstrated in this work that epitaxial layers suitable for fabrication of AlGaAs/GaAs HBT's with a carbon base doping level of up to 10sp{20} cmsp{-3} can be grown by solid source MBE using CBrsb4 as a doping precursor. The DC gain of HBT's with extremely heavily doped base layers was studied to determine the base thickness which will provide the lowest possible base resistance and a current gain still acceptable for fabrication of microwave HBT's. Use of iodine for in situ etching and surface cleaning of GaAs, AlGaAs and InGaAs and InGaAs in the MBE growth chamber is demonstrated for the first time. In-situ etching and growth capabilities integrated in the same chamber were used for fabrication of AlGaAs/GaAs HBT's with selectively buried sub-collectors for reduction of base-collector capacitance. Fabrication of these device structures was successfully demonstrated by MBE regrowth on pre-patterned sub-collector mesa structures. Growth of GaAs and AlGaAs layers under an intentional flux of Isb2 molecules was explored in molecular beam epitaxy. An improvement of material quality which coincides with the history of iodine use in the MBE chamber was observed.

Micovic, Miroslav

174

Silicon Nitride Final Passivation for GaAs Metal Semi-Conductor Field Effect Transistors (MESFETs) Packaged in Plastic Mold  

NASA Astrophysics Data System (ADS)

A highly reliable SiNx final passivation film for GaAs metal semi-conductor field effect transistor (MESFETs) packaged in plastic mold has been developed. The addition of He to N2 for the carrier gas in plasma enhanced chemical vapor deposition (PE-CVD) has been found effective to reduce both stress and pinholes and to significantly improve the resistance to moisture of the SiNx film. Rutherford back scattering (RBS), hydrogen forward scattering (HFS) and FT-IR analyses demonstrated that the SiNx with less pinhole has fewer hydrogen atoms in the film. Regarding the FETs housed in the SOT-89 mold package, no failure was observed up to 1000 h in the 85°C-85% relative humidity (RH) reverse bias test.

Saito, Yoshihiro; Tosaka, Yasuhiro; Nakajima, Shigeru

2003-11-01

175

Scanning electron and laser beams induced current (SELBIC) method for observing failures in GaAs high electron mobility transistors  

NASA Astrophysics Data System (ADS)

The electrical imaging observation of failures in GaAs high electron mobility transistors (HEMTs) is performed using scanning electron and laser beams induced current (SELBIC) method. An electron beam and infrared (IR) laser beam with a wavelength of 1064 nm irradiate coaxially from each side of a HEMT sample. When HEMT sample#1 and #2 are scanned from the back surface using a laser beam, a high contrast spot in the current image of sample#1 was observed between the gate and source regions. Since the I-V characteristic between the gate and source shows an increase in leakage current, the high contrast spot in the current image is suggested to be an electrically active failure. The current image is compared with the image under electron beam irradiation. It is ascertained by a cross sectioning technique with focused ion beam (FIB). The current spot is due to a crack causing a local short circuit in an insulating layer.

Sueyoshi, Haruki; Takasu, Shin-Ichi; Choi, Woon; Tomokage, Hajime

2009-04-01

176

Electron Transport Behavior on Gate Length Scaling in Sub-50 nm GaAs Metal Semiconductor Field Effect Transistors  

SciTech Connect

Short channel GaAs Metal Semiconductor Field Effect Transistors (MESFETs) have been fabricated with gate length to 20 nm, in order to examine the characteristics of sub-50 nm MESFET scaling. Here the rise in the measured transconductance is mainly attributed to electron velocity overshoot. For gate lengths below 40 nm, however, the transconductance drops suddenly. The behavior of velocity overshoot and its degradation is investigated and simulated by using a transport model based on the retarded Langevin equation (RLE). This indicates the existence of a minimum acceleration length needed for the carriers to reach the overshoot velocity. The argument shows that the source resistance must be included as an internal element, or appropriate boundary condition, of relative importance in any model where the gate length is comparable to the inelastic mean free path of the carriers.

Han, Jaeheon [Department of Electronic Engineering, Kangnam University, 111 Gugal-dong, Giheung-gu, Yongin-city, Gyeonggi-do, Korea 446-702 (Korea, Republic of)

2011-12-23

177

Radiation effects in III-V semiconductors and heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

The electron, gamma and neutron radiation degradation of III-V semiconductors and heterojunction bipolar transistors (HBTs) is investigated in this thesis. Particular attention is paid to InP and InGaAs materials and InP/InGaAs abrupt single HBTs (SHBTs). Complete process sequences for fabrication of InP/ InGaAs HBTs are developed and subsequently employed to produce the devices, which are then electrically characterized and irradiated with the different types of radiation. A comprehensive analytical HBT model is developed and radiation damage calculations are performed to model the observed radiation-induced degradation of SHBTs. The most pronounced radiation effects found in SHBTs include reduction of the common-emitter DC current gain, shift of the collector-emitter (CE) offset voltage and increase of the emitter, base and collector parasitic resistances. Quantitative analysis performed using the developed model demonstrates that increase of the neutral bulk and base-emitter (BE) space charge region (SCR) components of the base current are responsible for the observed current gain degradation. The rise of the neutral bulk recombination is attributed to decrease in a Shockley-Read-Hall (SRH) carrier lifetime, while the SCR current increase is caused by rising SCR SRH recombination and activation of a tunneling-recombination mechanism. On the material level these effects are explained by displacement defects produced in a semiconductor by the incident radiation. The second primary change of the SHBT characteristics, CE offset voltage shift, is induced by degradation of the base- collector (BC) junction. The observed rise of the BC current is brought on by diffusion and recombination currents which increase as more defects are introduced in a semiconductor. Finally, the resistance degradation is attributed to deterioration of low-doped layers of a transistor, and to degradation of the device metal contacts.

Shatalov, Alexei

178

Indium Phosphide-Based Heterojunction Bipolar Transistor Technology for High-Speed Devices and Circuits.  

NASA Astrophysics Data System (ADS)

The theoretical predictions for the performance of Heterojunction Bipolar Transistors (HBTs) have been largely based on models devised for silicon bipolar junction transistors (BJT). A careful inspection of the DC forward and reverse injection properties of HBTs has revealed that they are not reciprocal because of the heterojunction. The RF characteristics derived from an advanced network model indicated that f_{t} and f_{max} must be redefined since h_{21} and U can no longer be considered single pole functions. A variety of InP-based HBTs have been fabricated and characterized. The layer structures were grown by conventional molecular beam epitaxy (MBE) and by chemical beam epitaxy (CBE). A totally self-aligned base and emitter metal process was developed to characterize their DC and RF performances. The CBE grown structures included InAlAs/InGaAs and InP/InGaAs single HBTs and InAlAs/InGaAs/InGaAsP double HBTs. The various structures showed comparable current gains (beta~ 100) but the different injecting and collecting junctions resulted in variations in turn-on voltages, ideality factors and offset voltages. Because of the large bandgap InGaAsP collector in the double HBT, its breakdown voltage (8V) is significantly larger than that of the single HBTs (2.5V). The microwave performance of all these HBTs is dominated by parasitics. The low doping efficiency of the CBE significantly increases the base resistance and the emitter access resistance. The MBE grown HBT was a conventional InAlAs/InGaAs HBT with very heavily doped contact layers. The DC measurements showed lower current gain (beta~ 60) due to high base doping but demonstrated excellent Gummel and breakdown characteristics. Microwave measurements yielded an f_{t} and f_{max} of 65 and 78 GHz, respectively. Cryogenic DC measurements were performed to study the injection and recombination mechanisms at the base -emitter junction. At low temperatures, tunneling injection and bulk base recombination dominate while at room temperature themionic emission and other recombination processes are activated. Microwave measurements at various temperature revealed that both f_{t} and f_{max} improve as the temperature is lowered. The measured RF parameters of the MBE InAlAs/InGaAs HBT were used to design oscillators, amplifiers and photoreceivers. The oscillators operated at 7 and 14 GHz with output powers of 4 and 2 mW. The transimpedance amplifiers demonstrated a bandwidth of 17 GHz with a transimpedance of 40 dB Omega. The photoreceivers showed an optical bandwidth of 7 GHz and clearly open eye diagrams at 3 Gbits/s.

Cowles, John Charles, Jr.

179

TRANSISTORIZATION  

Microsoft Academic Search

Transistor and semiconductor diodes, compared with vacuum tubes in ; nucleonic instruments, offer the advantages of increased reliability, smaller ; size, and cooler operation. These elements are already replacing tubes ia all ; trigger and switching circuits in the field. Recently developed transistors open ; the way for transistorization of the remaining circuits basic a radiation ; detection systems. Problems

Goulding

1959-01-01

180

Theoretical comparison of Si, Ge, and GaAs ultrathin p-type double-gate metal oxide semiconductor transistors  

NASA Astrophysics Data System (ADS)

Based on a self-consistent multi-band quantum transport code including hole-phonon scattering, we compare current characteristics of Si, Ge, and GaAs p-type double-gate transistors. Electronic properties are analyzed as a function of (i) transport orientation, (ii) channel material, and (iii) gate length. We first show that <100>-oriented devices offer better characteristics than their <110>-counterparts independently of the material choice. Our results also point out that the weaker impact of scattering in Ge produces better electrical performances in long devices, while the moderate tunneling effect makes Si more advantageous in ultimately scaled transistors. Moreover, GaAs-based devices are less advantageous for shorter lengths and do not offer a high enough ON current for longer gate lengths. According to our simulations, the performance switching between Si and Ge occurs for a gate length of 12 nm. The conclusions of the study invite then to consider <100>-oriented double-gate devices with Si for gate length shorter than 12 nm and Ge otherwise.

Dib, Elias; Bescond, Marc; Cavassilas, Nicolas; Michelini, Fabienne; Raymond, Laurent; Lannoo, Michel

2013-08-01

181

Monolithic integration of an AlGaAs/GaAs multiquantum well laser and GaAs metal-semiconductor field-effect transistors on a semi-insulating GaAs substrate by molecular beam epitaxy  

SciTech Connect

AlGaAs/GaAs multiquantum well lasers and GaAs metal-semiconductor field-effect transistors have been monolithically integrated on a semi-insulating GaAs substrate by using molecular beam epitaxy. This integrated laser has exhibited cw operation with the low threshold current of 20 mA at room temperature. The laser/field-effect transistor (FET) characteristics, such as a linear control of laser output power by changing the FET gate voltage, have been confirmed. A conversion ratio of laser output power to FET gate voltage has been measured to be as high as 3.3 mW/V. Rise and fall times of 1 ns have been demonstrated.

Sanada, T.; Yamakoshi, S.; Wada, O.; Fujii, T.; Sakurai, T.; Sasaki, M.

1984-02-01

182

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

NASA Astrophysics Data System (ADS)

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

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

2011-10-01

183

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); Ren, F.; Zhang, A.P.; Dang, G.T. [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); Wilson, R.G. [Consultant, Stevenson Ranch, California 91381 (United States)

1999-05-01

184

Degradation of InGaAs/InP double heterojunction bipolar transistors under electron irradiation  

SciTech Connect

The dc characteristics of InGaAs/InP double heterojunction bipolar transistors (DHBT`s) are studied under high-energy ({approximately}1 MeV) electron irradiation up to a fluence of 14.8 {times} 10{sup 15} electrons/cm{sup 2}. The devices show an increase in common-emitter current gain (h{sub fe}) at low levels of dose (<10{sup 15} electrons/cm{sup 2}) and a gradual decrease in h{sub fe} and an increase in output conductance for higher doses. The decrease in h{sub fe} is as much as {approximately}80% at low base currents ({approximately}10 {micro}A) after a cumulative dose of 14.8 {times} 10{sup 15} electrons/cm{sup 2}. The observed degradation effects in collector current-voltage (I-V) characteristics are studied quantitatively using a simple SPICE-like device model. The overall decrease in h{sub fe} is attributed to increased recombination in the emitter-base junction region caused by radiation-induced defects. The defects introduced in the collector-base junction region are believed to be responsible for the observed increase in the output conductance.

Bandyopadhyay, A.; Subramanian, S. [Oregon State Univ., Corvallis, OR (United States). Dept. of Electrical and Computer Engineering; Chandrasekhar, S.; Dentai, A.G. [Lucent Technologies, Holmdel, NJ (United States). Bell Labs.; Goodnick, S.M. [Arizona State Univ., Tempe, AZ (United States). Dept. of Electrical Engineering

1999-05-01

185

A novel wide-dynamic-range logarithmic-response bipolar junction photogate transistor for CMOS imagers  

NASA Astrophysics Data System (ADS)

In this paper, a new photodetector, bipolar junction photogate transistor (BJPG), is proposed for CMOS imagers. Due to an injection p^(+)n junction introduced, the photo-charges drift through the p^(+)n junction by the applied electronic field, and on the other hand, the p^(+)n junction injects the carriers into the channel to carry the photo-charges. Therefore this device can increase the readout rate of the pixel signal charges and the photoelectron transferring efficiency. Using this new device, a new type of logarithmic pixel circuit is obtained with a wide dynamic range which makes photo-detector more suitable for imaging the naturally illuminated scenes. The simulations show that the photo current density of BJPG increases logarithmically with the incident light power due to the introduced injection p+n junction. The noise characteristics ofBJPG are analyzed in detail and a new gate-induced noise is proposed. Based on the established numerical analytical model of noise, the power spectrum density curves are simulated.

Jin, Xiangliang; Chen, Jie; Qiu, Yulin

2003-08-01

186

Systematic investigation of monolithic bipolar transistors irradiated with neutrons, heavy ions and electrons for space applications  

NASA Astrophysics Data System (ADS)

In this paper, experimental results of radiation effects on a BiCMOS high speed commercial technology, manufactured by ST-Microelectronics, are reported after irradiation with 9.1 MeV electrons. The data are compared with those previously obtained by irradiations with fast-neutrons, 12C-, 13C-, Ar- and Kr-ions. 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, which results in creating recombination centers. As a consequence, the lifetime of the minority-carriers in the base is decreased and the common-emitter current gain (?) is degraded. The gain degradation was investigated for collector current Ic between 1 ?A and 1 mA. The linear dependence of ?(1/?) = 1/?irr - 1/? (where ?irr and ? are the gain after and before the irradiation) as a function of the concentration of Frenkel pairs was confirmed. The bipolar transistors made on this technology have shown to be particularly radiation resistant. Base and collector currents were systematically investigated, as well as, the effect of self-annealing.

Consolandi, C.; D'Angelo, P.; Fallica, G.; Mangoni, R.; Modica, R.; Pensotti, S.; Rancoita, P. G.

2006-11-01

187

High total dose gamma radiation assessment of commercially available SiGe heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

Maintenance tasks of the future International Experimental Thermonuclear fusion Reactor (ITER) will require communication links between the remotely operated equipment in the reactor vessel and the control room, some of which need to be radiation tolerant up to MGy dose levels. As a key element of opto-electronic transceivers, we therefore assessed the DC behavior of a commercial-off-the-shelf (COTS) SiGe heterojunction bipolar transistor (HBT) under gamma radiation up to 15 MGy, with dose rates from 160 Gy/h to 27 kGy/h. Our in-situ measurements of the forward DC current gain (hfe) present a limited loss of about 30 % for a base current of 100 ?A, with a dependence on the biasing conditions and a thermally activated recovery. These first ever reported results up to MGy levels allow us to design circuit-hardened driving electronics for both photonic transmitters and receivers, enabling high bandwidth communications applied in a fusion reactor environment.

Van Uffelen, Marco; Geboers, Sam; Leroux, Paul; Berghmans, Francis

2005-09-01

188

An improved bipolar junction transistor model for electrical and radiation effects  

NASA Astrophysics Data System (ADS)

A bipolar transistor model is introduced which combines most of the best features of the modified Ebers-Moll (1954) model with the Gummel-Poon (1970) model. The model is constructed of two modified Ebers-Moll models with the addition of junction and basewidth modulation to account for leakage current dependence on reverse voltage and beta dependence on collector-emitter voltage. The electrical characteristics that can be obtained with the model include: nonlinear beta and V(BE) vs normal I(C) and/or inverted I(E); increase in f(T) from low injection to peak beta and decrease in f(T) beyond peak beta; nonlinear R(CX) vs I(C) and V(CE); inclusion of base-width modulation as a function of reverse bias for V(CB) or V(EB); and inclusion of junction leakage as a function of reverse bias. Radiation characteristics that can be obtained include: photocurrent generation and saturation including photocurrent response time; dose-rate modulation of resistors; inclusion of neutron damage constant as a function of injection level and incorporation of fast annealing; inclusion of temperature dependence.

Kleiner, C. T.; Messenger, G. C.

1982-12-01

189

Stability of Measurement of Heterojunction Bipolar Transistors Current-Voltage Characteristics with Thermal Effect  

NASA Astrophysics Data System (ADS)

To obtain a reliable design, a careful determination of model parameters is needed. In this study, the thermally stable time of collector current (IC) of heterojunction bipolar transistors (HBTs) operated at different biasing points is observed. It is observed that the stable time of IC is different with different biasing points. The maximum thermally stable time is about 72 ms in this study. For the conventional measurement method, the default biasing time of current-voltage (IC-VCE) curves at each bias point is about 20 ms. The calculated thermal resistance and junction temperature obtained by the conventional measurement are quite different from those obtained by thermally stable measurement. In this work, we found that the thermal resistance obtained by thermally stable measurement (i.e. sufficiently long biasing time) is smaller than that obtained by conventional measurement. Moreover, the junction temperature estimated from the former is smaller than that from the latter. It is obvious that the biasing time of every measurement point must be ascertained by using the curve of IC versus biasing time with the operation VCE.

Wei, Sun-Chin; Su, Yan-Kuin; Wang, Ruey-Lue

2002-12-01

190

DC Characterization of InP/InGaAs Tunneling Emitter Bipolar Transistor  

NASA Astrophysics Data System (ADS)

An InP/InGaAs tunneling emitter bipolar transistor (TEBT) is studied and demonstrated. From the simulation results, the band diagram, tunneling transmission, and carrier distribution of the device are analyzed as functions of barrier thickness. The higher the emitter injection efficiency, the higher the current gain and the larger the current drivability for the device studied by employing a tunneling barrier layer of suitable thickness. In addition, experimentally, InP/InGaAs TEBT has been fabricated successfully. Due to its excellent tunneling barrier structure, the studied device can be operated under an extremely wide collector current range. The operation range is larger than 11 decades of collector current (10-12 to 10-1 A). Moreover, the studied device exhibits a very small collector-emitter offset voltage (? VCE) of 40 mV and an extremely wide operation range of output current. Thus, the studied device is suitable for low-voltage and low-power circuit applications.

Cheng, Shiou-Ying; Chen, Chun-Yuan; Fu, Ssu-I; Lai, Po-Hsien; Tsai, Yan-Ying; Liu, Wen-Chau

2005-02-01

191

Multi-level interconnects for heterojunction bipolar transistor integrated circuit technologies  

SciTech Connect

Heterojunction bipolar transistors (HBTs) are mesa structures which present difficult planarization problems in integrated circuit fabrication. The authors report a multilevel metal interconnect technology using Benzocyclobutene (BCB) to implement high-speed, low-power photoreceivers based on InGaAs/InP HBTs. Processes for patterning and dry etching BCB to achieve smooth via holes with sloped sidewalls are presented. Excellent planarization of 1.9 {micro}m mesa topographies on InGaAs/InP device structures is demonstrated using scanning electron microscopy (SEM). Additionally, SEM cross sections of both the multi-level metal interconnect via holes and the base emitter via holes required in the HBT IC process are presented. All via holes exhibit sloped sidewalls with slopes of 0.4 {micro}m/{micro}m to 2 {micro}m/{micro}m which are needed to realize a robust interconnect process. Specific contact resistances of the interconnects are found to be less than 6 {times} 10{sup {minus}8} {Omega}cm{sup 2}. Integrated circuits utilizing InGaAs/InP HBTs are fabricated to demonstrate the applicability and compatibility of the multi-level interconnect technology with integrated circuit processing.

Patrizi, G.A.; Lovejoy, M.L.; Schneider, R.P. Jr.; Hou, H.Q. [Sandia National Labs., Albuquerque, NM (United States); Enquist, P.M. [Research Triangle Inst., Research Triangle Park, NC (United States)

1995-12-31

192

A comparison of the effects of gamma irradiation on SiGe HBT and GaAs HBT technologies  

Microsoft Academic Search

A comparison of the effects of gamma irradiation on silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) and gallium-arsenide (GaAs) HBT technologies is reported, DC and radiofrequency (RF) performance as well as the low frequency noise are investigated for gamma doses up to 1 Mrad(Si). The results indicate that both SiGe and GaAs HBT technologies are tolerant to gamma irradiation

Shiming Zhang; Guofu Niu; John D. Cressler; Suraj J. Mathew; Usha Gogineni; Steven D. Clark; Peter Zampardi; Richard L. Pierson

2000-01-01

193

The current status and the principal problems of developing microwave transistors \\/Review  

Microsoft Academic Search

The state-of-the-art of microwave transistors is reviewed with reference to published theoretical and experimental work in this field. In particular, attention is given to the development of bipolar and field transistors, hybrid integrated circuits, and monolithic integrated circuits including low-noise input devices, high-power circuits, digital logic circuits, and GaAs circuits combining digital and analytic signal processing. Finally, future prospects for

V. V. Muravev; N. M. Naumovich

1982-01-01

194

Inversion-type enhancement-mode HfO2-based GaAs metal-oxide-semiconductor field effect transistors with a thin Ge layer  

NASA Astrophysics Data System (ADS)

Using a thin germanium (Ge) interfacial passivation layer (IPL), GaAs HfO2-based inversion-type enhancement-mode metal-oxide-semiconductor field effect transistors (MOSFETs) are realized. The n-channel MOSFETs on semi-insulating GaAs substrate clearly show surface modulation and excellent current control by gate bias. The threshold voltage of ~0.5 V, the transconductance of ~0.25 mS/mm, the subthreshold swing of ~130 mV/decade, and the drain current of ~162 ?A/mm (normalized to the gate length of 1 ?m) at Vd=2 V and Vg=Vth+2 V are obtained. In comparison with previous reports, the dc characteristics of the inversion-type GaAs MOSFETs with a Ge IPL and HfO2 dielectric demonstrate much similar results.

Kim, Hyoung-Sub; Ok, I.; Zhang, M.; Zhu, F.; Park, S.; Yum, J.; Zhao, H.; Lee, Jack C.; Oh, Jungwoo; Majhi, Prashant

2008-01-01

195

Optimization, analysis, and fabrication of silicon-germanium heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

This thesis deals with the optimization, analysis, and fabrication of silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs). Two vertical base profile optimization studies for improving the high-frequency performance of SiGe HBTs are presented. In the first study, the Ge profile is optimized for the minimum contribution of the emitter and base delay times to the transition frequency in the low-injection regime. A fixed Ge dose is used as the optimization constraint. Non-quasi-static effects at high frequencies are taken into account. It is shown that the graded Ge profile is more effective than the box Ge profile in minimizing the two delay time contributors for SiGe HBTs with today's typical emitter and base dimensions. In the second optimization study, the base doping and Ge profiles are optimized for minimum base delay time in low- and high-injection regimes before the onset of Kirk effect. Fixed Ge dose, intrinsic base resistance, and base concentration near the emitter are adopted as optimization constraints. The effect of plasma-induced bandgap narrowing in high injection is considered. An iteration scheme for calculating the base delay time for a wide range of collector current densities is developed. It is shown that the retrograde base doping profile with graded Ge profiles gives the minimum base delay time in both low- and high-injection regimes. An analysis of the retrograde portion of a base retrograde doping profile in a SiGe HBT is also performed. A closed-form analytical expression of the base delay time is derived with various physical effects taken into consideration. The relative importance of the physical effects is assessed. It is found that the adverse effect of the retrograde portion of the base retrograde doping profile on the base delay time is less pronounced than expected, especially when a high Ge grading exists across the base. It is also shown that the effect of the field dependency of the electron diffusivity needs to be considered when modelling the base delay time in the SiGe base with a high electric field. Finally, SiGe HBTs are fabricated by high-dose Ge implantation, Si amorphization, and solid-phase epitaxy. The results from electrical measurements are presented. Although further work is required in this area, transistor action is observed in SiGe HBTs with Si amorphization used.

Kwok, Kai Hay

196

Electron irradiation effects in polyimide passivated InP/InGaAs single heterojunction bipolar transistors  

SciTech Connect

In this paper, the authors report the effects of high-energy electron irradiation on the DC characteristics of polyimide passivated InP/InGaAs single heterojunction bipolar transistors. In contrast with the results of electron irradiation of unpassivated devices, the polyimide-passivated devices show much less degradation of current gain and no change in the collector output conductance. The decrease of collector current in the active regime is found to be typically {approximately}9% for a cumulative equivalent 1-MeV dose of 2.7 x 10{sup 16} e/cm{sup 2} ({approximately}620 Mrad (InGaAs)). For low base currents, the devices show an increase in the current gain for smaller doses (< 2.5 x 10{sup 15} e/cm{sup 2}) followed by a decrease at the higher doses. The increase in the current gain at low doses is attributed to the trapped charge in the polyimide layer near the periphery of the B-E junction. The most significant effect of electron irradiation on the passivated devices is a decrease in the slope of the I{sub C}-V{sub CE} characteristics of some devices in the saturation regime. They believe this decrease in slope is caused by an increase in the collector series resistance after irradiation. Finally, devices with smaller emitter size are shown to have less radiation degradation than the larger emitter devices. This is explained by the smaller radiation damage at the junction peripheries of the passivated devices.

Shatalov, A.; Subramanian, S.; Chandrasekhar, S.; Dentai, A.; Goodnick, S.M.

1999-12-01

197

GAAS ICS and HEMT for supercomputer  

SciTech Connect

The desire to improve computer speed is growing without limits, especially in scientific applications. A supercomputer is the high speed computer to meet this desire in the fields such as nuclear physics, weather forecast, and search for resources. The supercomputer performance is being improved by introducing new technologies in hardware, software and devices, while hardware and software technologies can be developed to satisfy specific requirements, the improvement of device performance is essential and effective for both general purpose computer and supercomputers. Various devices such as si bipolar transistor, short channel si MOS FET, GAAS FET, HEMT (high electron mobility transistor) and Josephson junction devices are candidates for the high speed logic circuits of supercomputers. Because of their high electron mobility and low stray capacitance, 3-5 compound devices such as GAAS FET and HEMT will give important breakthroughs in the development of high speed computers. 9 references.

Misugi, T.; Kurokawa, K.

1982-01-01

198

Thermally Stable Structure of InGaP/GaAs Hetero-junction Bipolar Transistor: Dual-Emitter Structure  

NASA Astrophysics Data System (ADS)

We propose a new structure of InGaP/GaAs Hetero-junction Bipolar Transistor (HBT) with dual emitter fingers for power amplifier application, which is optimized for uniform thermal distribution within the device. The optimized thermal management of the proposed HBT relaxes the current decrease by a factor of 1.41 under active current bias, and prevents current gain collapse up to VCE of 8 V, while a conventional device shows a significant collapse at VCE=6.2 V.

Lee, You Sang; Park, Chul Soon

2002-04-01

199

Experimental study on short-circuit characteristics of the new protection circuit of insulated gate bipolar transistor  

NASA Astrophysics Data System (ADS)

A new protection circuit employing the collector to emitter voltage (VCE) sensing scheme for short-circuit withstanding capability of the insulated gate bipolar transistor (IGBT) is proposed and verified by experimental results. Because the current path between the gate and collector can be successfully eliminated in the proposed protection circuit, the power consumption can be reduced and the gate input impedance can be increased. Previous study is limited to dc characteristics. However, experimental results show that the proposed protection circuit successfully reduces the over-current of main IGBT by 80.4% under the short-circuit condition.

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

2006-09-01

200

Growth and characterization of novel multilayer heterostructures for the monolithic integration of resonant-cavity photodiodes and heterojunction bipolar transistors  

SciTech Connect

We describe the layer structures, crystal-growth conditions, and characteristics of novel multilayers in the InGaAlAs/InGaAs/InAlAs materials system for the monolithic integration of heterojunction bipolar transistors (HBTs) and resonant-cavity photodiodes. The photodiodes are formed of the base and collector regions of the HBT layer. The use of a resonant cavity improves the quantum efficiency for an absorbing layer of given thickness. The HBTs had high current gains and well-behaved Gummel plots. The absorption and photocurrent characteristics of the resonant photodiodes show a {approximately} 100% enhancement at resonance. 11 refs., 3 figs.

Dodabalapur, A.; Chang, T.Y.; Chandrasekhar, S. [AT& T Bell Lab., Holmdel, NJ (United States)

1993-05-01

201

Modeling and Simulation of - and Silicon Germanium-Base Bipolar Transistors Operating at a Wide Range of Temperatures.  

NASA Astrophysics Data System (ADS)

Higher speed at lower cost and at low power consumption is a driving force for today's semiconductor technology. Despite a substantial effort toward achieving this goal via alternative technologies such as III-V compounds, silicon technology still dominates mainstream electronics. Progress in silicon technology will continue for some time with continual scaling of device geometry. However, there are foreseeable limits on achievable device performance, reliability and scaling for room temperature technologies. Thus, reduced temperature operation is commonly viewed as a means for continuing the progress towards higher performance. Although silicon CMOS will be the first candidate for low temperature applications, bipolar devices will be used in a hybrid fashion, as line drivers or in limited critical path elements. Silicon -germanium-base bipolar transistors look especially attractive for low-temperature bipolar applications. At low temperatures, various new physical phenomena become important in determining device behavior. Carrier freeze-out effects which are negligible at room temperature, become of crucial importance for analyzing the low temperature device characteristics. The conventional Pearson-Bardeen model of activation energy, used for calculation of carrier freeze-out, is based on an incomplete picture of the physics that takes place and hence, leads to inaccurate results at low temperatures. Plasma -induced bandgap narrowing becomes more pronounced in device characteristics at low temperatures. Even with modern numerical simulators, this effect is not well modeled or simulated. In this dissertation, improved models for such physical phenomena are presented. For accurate simulation of carrier freeze-out, the Pearson-Bardeen model has been extended to include the temperature dependence of the activation energy. The extraction of the model is based on the rigorous, first-principle theoretical calculations available in the literature. The new model is shown to provide consistently accurate values for base sheet resistance for both Si- and SiGe-base transistors over a wide range of temperatures. A model for plasma-induced bandgap narrowing suitable for implementation in a numerical simulator has been developed. The appropriate method of incorporating this model in a drift -diffusion solver is described. The importance of including this model for low temperature simulation is demonstrated. With these models in place, the enhanced simulator has been used for evaluating and designing the Si- and SiGe-base bipolar transistors. Silicon-germanium heterojunction bipolar transistors offer significant performance and cost advantages over conventional technologies in the production of integrated circuits for communications, computer and transportation applications. Their high frequency performance at low cost, will find widespread use in the currently exploding wireless communication market. However, the high performance SiGe-base transistors are prone to have a low common-emitter breakdown voltage. In this dissertation, a modification in the collector design is proposed for improving the breakdown voltage without sacrificing the high frequency performance. A comprehensive simulation study of p-n-p SiGe-base transistors has been performed. Different figures of merit such as drive current, current gain, cut -off frequency and Early voltage were compared between a graded germanium profile and an abrupt germanium profile. The differences in the performance level between the two profiles diminishes as the base width is scaled down.

Shaheed, M. Reaz

1995-01-01

202

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

203

Development of a 4-Bit Parallel Analog-To-Digital Converter and a Four-Quadrant Double-Balanced Mixer Using Heterojunction Bipolar Transistor Technology.  

National Technical Information Service (NTIS)

A 4-bit parallel analog-to-digital converter (ADC) and a four-quadrant double-balanced mixer were designed and simulated using heterojunction bipolar transistor (HBT) technology to test the dc and high-frequency characteristics of HBTs. HSPICE simulations...

S. F. Jokerst

1993-01-01

204

On the choice of a element low-noise preamplifier on bipolar transistors  

Microsoft Academic Search

The dependence of the preamplifier equivalent noise charge (ENC) on the detector capacitance, shaping time and collector current of the head transistor is presented. The measurement results are in a good agreement with calculations based on a simple noise model, so tedious ENC measurements may be replaced by a simple selection of transistors on distributed base resistance and current gain

R. N. Krasnokutskij; L. L. Kurchaninov; V. V. Tikhonov; N. N. Fedyakin; R. S. Shuvalov

1986-01-01

205

Material and device studies for the development of gallium nitride heterojunction bipolar transistors by molecular beam epitaxy  

NASA Astrophysics Data System (ADS)

Due to its unique physical properties, gallium nitride (GaN) is under intense investigation for the development of transistors for high power, high frequency and high temperature applications. The majority of existing literature addresses field effect transistors. This dissertation addresses a wide spectrum of materials and device studies required for the development of GaN-based heterojunction bipolar transistors (HBTs). The investigated structure has the emitter region based on n-Al xGa1-xN alloys, while the base and collector were based on p-InyGa1-yN and n-GaN, respectively. The growth and doping of the various layers of the transistor structure, on sapphire substrate, GaN-templates and free standing GaN substrates are addressed. Particular emphasis was placed on the p-type doping of the AlGaN and InGaN alloys with magnesium, both doping of bulk films as well as superlattices. The experimental results were compared with theoretical predictions of a self-consistent solution to the one-dimensional poisson and schrodinger equations. A hole concentration for p-InGaN of 9x1018CM-3 was obtained, which is the highest value published. The device aspect of this research addressed issues related to the development of novel methods of selective growth by molecular beam epitaxy (MBE) of the emitter onto the base. This was found to be necessary to avoid damage of the base during mesa etching. The final product of this research was the fabrication and DC characterization of HBT devices. This included various lithography, metallization, etching and annealing steps. The devices were evaluated under common base and common emitter configurations and the best result obtained was a room temperature gain of 59.

Li, Wei

206

Choice of a Element Low-Noise Preamplifier on Bipolar Transistors.  

National Technical Information Service (NTIS)

The dependence of the preamplifier equivalent noise charge (ENC) on the detector capacitance, shaping time and collector current of the head transistor is presented. The measurement results are in a good agreement with calculations based on a simple noise...

R. N. Krasnokutskij L. L. Kurchaninov V. V. Tikhonov N. N. Fedyakin R. S. Shuvalov

1986-01-01

207

Degradation of dc characteristics of InGaAs/InP single heterojunction bipolar transistors under electron irradiation  

SciTech Connect

The effects of high-energy ({approximately}1 MeV) electron irradiation on the dc characteristics of InGaAs/InP single heterojunction bipolar transistors (SHBT`s) are investigated. The device characteristics do not show any significant change for electron doses <10{sup 15}/cm{sup 2}. For higher doses, devices show a decrease in collector current, a degradation of common-emitter current gain, an increase in collector saturation voltage and an increase in the collector output conductance. A simple SPICE-like device model is developed to describe the dc characteristics of SHBT`s. The model parameters extracted from the measured dc characteristics of the devices before and after irradiation are used to get an insight into the physical mechanisms responsible for the degradation of the devices.

Bandyopadhyay, A.; Subramanian, S. [Oregon State Univ., Corvallis, OR (United States). Dept. of Electrical and Computer Engineering; Chandrasekhar, S.; Dentai, A.G. [Lucent Technologies, Holmdel, NJ (United States). Bell Labs.; Goodnick, S.M. [Arizona State Univ., Tempe, AZ (United States). Dept. of Electrical Engineering

1999-05-01

208

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

209

Root-Cause Analysis and Statistical Process Control of Epilayers for SiGe:C Hetero-Structure Bipolar Transistors  

NASA Astrophysics Data System (ADS)

The SiGe:C hetero-structure bipolar transistor (HBT) has turned into a key technology for wireless communication. This paper describes various critical analytical techniques to bring up and maintain the SiGe:C epi-process. Two types of analysis are critical, (1) routine monitoring SiGe base and Si cap thickness, doping dose, Ge composition profile, and their uniformity across the wafer; and (2) root-cause analysis on problems due to non-optimized process and variation in process conditions. A transmission electron microscopy (TEM) technique has been developed allowing a thickness measurement with a reproducibility better than 3 Ĺ. Charge-compensated low-energy secondary ion mass spectrometry (SIMS) using optical conductivity enhancement (OCE) allows a Ge composition measurement to a required precision of 0.5 at. %.

Xie, Qianghua; Duda, Erika; Kottke, Mike; Qin, Wentao; Wang, Xiangdong; Lu, Shifeng; Erickson, Martha; Kretzschmar, Heather; Cross, Linda; Murphy, Sharon

2003-09-01

210

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

NASA Astrophysics Data System (ADS)

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

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

2010-04-01

211

Investigation of temperature dependence on heterojunction bipolar light-emitting transistors embedded InGaAs/GaAs quantum wells  

NASA Astrophysics Data System (ADS)

In this work, an analytical study of the temperature dependence of current gain and ideality factor (?) has been performed for the heterojunction bipolar light emitting transistor (HBLET). In order to utilize the radiative recombination, the structure of HBT embedded two quantum wells in the base region which can improve the radiation efficiency. Compare with the convention HBT, the temperature dependence of current gain increases 42.5% with increasing temperature from 350K followed by a decrease towards 300K. Variation of gain with temperature is different from that the characteristic of HBT adding another advantage in favor of the HBLET. The ?B of these devices are similar, revealing that the space-charge recombination dominates the overall base current. The high output power of HBLET is 962 ?W at 88 mA. These results reveal that the HBLET which combine electrical and optical characteristic device.

Huang, T. H.; Chang, H. J.; Huang, K. M.; Chiu, S. Y.; Lee, Y. L.; Hong, W. J.; Ho, C. L.; Wu, M. C.

2013-01-01

212

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

213

Conception d'UN Composant de Puissance a Grille Isolee IGBT Etude Statique et Dynamique (Design of a Power Component with IGBT (Insulated Gate Bipolar Transistor) Insulated Grid. Static and Dynamic Study).  

National Technical Information Service (NTIS)

Design rules for first and second generation IGBT (insulated gate bipolar transistors) for more than 400 volt power applications are derived from theoretical and simulation analysis. Implementation experiments including specifically designed manufacturing...

G. Rouault

1988-01-01

214

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

2011-07-30

215

Open Tube Double Diffusion for the Fabrication of Bipolar Transistor Waveguide Optical Switch.  

National Technical Information Service (NTIS)

Experimental results of a new method for the double diffusion into GaAs in an open tube have been presented. New techniques developed for the low concentration Zn diffusion at relatively higher values of the temperature and high concentration Sn diffusion...

D. K. Gautam Y. Nakano K. Tada

1992-01-01

216

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 A? 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

217

Simulation of Npn and Pnp AlGaN/GaN heterojunction bipolar transistors performances: Limiting factors and optimum design  

SciTech Connect

The performance capabilities of Npn and Pnp AlGaN/GaN heterojunction bipolar transistors have been investigated by using a drift-diffusion transport model. Numerical results have been employed to study the effect of the p-type Mg doping and its incomplete ionization on device performance. The high base resistance induced by the deep acceptor level is found to be the cause of limited current gain values for Npn devices. Several computation approaches have been considered to improve their performance. Reasonable improvement of the DC current gain {beta} is observed by realistically reducing the base thickness in accordance with processing limitations. Base transport enhancement is also predicted by the introduction of a quasi-electric field in the base. The impact of the base resistivity on high-frequency characteristics is investigated for Npn AlGaN/GaN devices. Optimized predictions with maximum oscillation frequency value as high as f{sub MAX} = 20 GHz and a unilateral power gain--U = 25 dB make this bipolar GaN-based technology compatible with communication applications. Simulation results reveal that the restricted amount of free carriers from the p-doped emitter limits Pnp's DC performances operating in common emitter configuration. A preliminary analysis of r.f. characteristics for the Pnp counterpart indicates limited performance mainly caused by the degraded hole mobility.

MONIER,C.; REN,F.; HAN,JUNG; CHANG,PING-CHIH; SHUL,RANDY J.; LEE,K.P.; ZHANG,A.P.; BACA,ALBERT G.; PEARTON,S.J.

2000-04-25

218

Physics and process-based bipolar transistor modeling for integrated circuit design  

Microsoft Academic Search

Many applications require circuits to be operated close to the performance limits of current silicon (production) processes to meet the required circuit specifications for, e.g., high speed, low noise, and low power consumption. Therefore, the circuits must be carefully optimized by selecting the individual transistor configurations. As a consequence, model parameters for a large variety of configurations (100 or more)

Michael Schroter; Hans-Martin Rein; Winfried Rabe; Reinhard Reimann; Hans-Joachim Wassener; Andreas Koldehoff

1999-01-01

219

Simple model for the GaAs HBT high-frequency performance under optical illumination  

NASA Astrophysics Data System (ADS)

A simple theory and a model for the GaAs heterojunction bipolar transistor's (HBT's) high-frequency performance under optical illumination are described. It is assumed that the major contribution to the photocurrent in the HBT is due to the photovoltaic effect in the base-collector depletion region. Estimations using PSPICE circuit simulator show photoresponse cutoff frequencies of several tens of gigahertz when some HBT parameters are adequately designed.

Desalles, Alvaro A.; Hackbart, Anelise S.; Spalding, Luiz N.

1994-06-01

220

GaAs HBT MMIC broadband amplifiers from DC to 20 GHz  

Microsoft Academic Search

Three monolithic wideband and high-gain amplifiers implemented with 2-3-?m GaAs heterojunction bipolar transistor (HBT) monolithic microwave IC (MMIC) technology are presented. A single-stage direct-coupled amplifier achieves a 3-dB bandwidth from DC to 20 GHz, which is believed to be the widest bandwidth reported for direct-coupled amplifiers. The amplifier has a 6-dB nominal gain with a peak gain of 7.3 dB

K. W. Kobayashi; D. K. Umemoto; R. Esfandiari; A. K. Oki; L. M. Pawlowicz; M. E. Hafizi; L. Tran; J. B. Camou; K. S. Stolt; D. C. Streit; M. E. Kim

1990-01-01

221

Linearity characteristics of GaAs HBTs and the influence of collector design  

Microsoft Academic Search

The linearity characteristics of GaAs heterojunction bipolar transistors (HBTs) are studied through measurement and analysis. Third-order intermodulation distortion behavior of HBTs is examined on devices with various epilayer designs and at various bias points, loads, and frequencies. Calculations from an analytical model reveal a strong bias and load dependence of third-order intercept point (IP3) on the nonlinearities from transconductance and

Masaya Iwamoto; Peter M. Asbeck; Thomas S. Low; Craig P. Hutchinson; Jonathan Brereton Scott; Alex Cognata; Xiaohui Qin; Lovell H. Camnitz; D. C. D'Avanzo

2000-01-01

222

Over 300 GHz fT and fmax InP\\/InGaAs double heterojunction bipolar transistors with a thin pseudomorphic base  

Microsoft Academic Search

Describes 150-nm-thick collector InP-based double heterojunction bipolar transistors with two types of thin pseudomorphic bases for achieving high fT and fmax. The collector current blocking is suppressed by the compositionally step-graded collector structure even at JC of over 1000 kA\\/cm2 with practical breakdown characteristics. An HBT with a 20-nm-thick base achieves a record fT of 351 GHz at high JC

Minoru Ida; Kenji Kurishima; Noriyuki Watanabe

2002-01-01

223

Saturation of the dose-rate response of bipolar transistors below 10 rad(SiO2)\\/s: implications for hardness assurance  

Microsoft Academic Search

The gain degradation of modern bipolar transistors was investigated for dose rates ranging from 0.01 to ~2000 rad(SiO2 )\\/s. Five different radiation sources were used for the exposures: three 60Co sources, a 10-keV X-ray source, and a 137 Cs source. The 137Cs exposures at 0.01 rad(SiO2 )\\/s are two orders of magnitude lower in dose rate than any previous irradiations

R. Nathan Nowlin; D. M. Fleetwood; R. D. Schrimpf

1994-01-01

224

Growth optimization for p-n junction placement in the integration of heterojunction bipolar transistors and quantum well modulators on InP  

Microsoft Academic Search

We demonstrate the necessary conditions for successful metalorganic vapor phase epitaxy (MOVPE) growth of InGaAs-InP-based heterojunction bipolar transistor (HBT) layers on p-i-n InGaAsP-InGaAsP quantum-well electroabsorption modulators. Optimization of the doping profile in the uppermost p-cladding layer of the modulator stack was achieved to obtain suitable p-n junction placement after the final HBT growth. Photoluminescence, electron beam induced current traces, scanning

M. T. Camargo Silva; J. E. Zucker; L. R. Carrion; C. H. Joyner; A. G. Dentai

2000-01-01

225

(In,Ga)As\\/InP n-p-n heterojunction bipolar transistors grown by liquid phase epitaxy with high DC current gain  

Microsoft Academic Search

Experimental results on heterojunction bipolar transistors made in liquid phase epitaxial (In,Ga)As and InP layers on InP substrates are described. The (In,Ga)As base layer was doped with manganese during growth and contacts were made to it by beryllium ion implantation. The maximum measured dc current gain ? of these devices was in excess of 500. These devices also demonstrate for

H. Kanbe; J. C. Vlcek; C. G. Fonstad

1984-01-01

226

A spaceborne experiment to determine the radiation sensitivity of microwave bipolar transistors  

NASA Astrophysics Data System (ADS)

The design and results of a spaceborne radiation experiment using the Orbital Test Satellite (OTS-2) to measure the degradation of a commonly used small-signal microwave transistor in the space environment are presented. The experiment utilizes a radiation damage monitoring unit consisting of three identical microwave transistors which are exposed to the space radiation environment plus an MOS-type dosimeter which measures the incident radiation. Any radiation-induced changes in the DC current-gain result in corresponding changes in the bias current, and these changes plus the incident radiation and the data are returned to the ground via telemetry. The results indicate that the actual space radiation levels are lower than those estimated by current prediction techniques.

Gibson, M. H.; Strijk, S. J. G.; Adams, L.

227

Realization and linearization of a hyperfrequency power amplifier implemented with bipolar transistors in class C polarization  

NASA Astrophysics Data System (ADS)

The design of a 10 W amplifier at 2.5 GHz and that of a power characteristic linearization device are discussed. The amplifier consists of 3 stages of transistors on a common base circuit with an MSC 3000 at the output. The linearization is obtained by an emitter polarization voltage related to the incident high frequency power. The circuit that elaborates the control signal is described. The results show the need to separate the stages.

Durand, Y.

1985-01-01

228

An efficient gate driver for high-power insulated gate bipolar transistors  

Microsoft Academic Search

This paper presents a novel FET\\/IGBT gate drive circuit for high power applications. Full galvanic isolation is provided, no floating power supplies are needed and continuous (DC) gate drive is possible. The circuit topology consists in essence of an inverter coupled to a synchronous rectifier. Bidirectional current flow to reverse-bias the gate is obtained by using field-effect transistors operating in

M. J. Case; J. J. Schoeman; G. Blajszczak; J. D. van Wyk

1994-01-01

229

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-Ĺ 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

230

A gate driver based soft-switching SiC bipolar junction transistor  

Microsoft Academic Search

This paper presented a new soft-switching concept that the soft transition is achieved based on gate driver control. A new soft-switched IGBT and MOSFET Gated Transistor (SS-IMGT) base drive structure is proposed for high power SiC BJT. The proposed base scheme can proportionally drive SiC BJT into near-saturate region. In addition, the zero voltage turn-on for BJT can be adaptively

Huijie Yu; Jason Lai; Xudong Huang; Jian H. Zhao; Jianhui Zhang; Xiangyang Hu; John Carter; Leonid Fursin

2003-01-01

231

Characterization, simulation and optimization of type-II gallium arsenic antimonide-based double heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

In recent years, GaAsSb/InP double heterojunction bipolar transistors (DHBTs) have been demonstrated to be promising alternatives to InP/InGaAs HBTs, for next generation microwave/millimeter wave applications and optoelectronic integrated circuits (OEICs). However, GaAsSb-based DHBTs featuring the novel base material and type-II band alignment have not been well studied. This thesis investigated type-II GaAsSb DHBTs in the following aspects: periphery surface recombination current, Kirk effect, two dimensional (2D) simulation and device optimization. The present work provided insights into device operation, and guidances for further device development. A series of physical models and parameters was implemented in 2D device simulations using ISE TCAD. Band gap narrowing (BGN) in the bases was characterized by comparing experimental and simulated results. Excellent agreements between the measured and simulated DC and RF results were achieved. Emitter size effects associated with the surface recombination current were experimentally characterized for emitter sizes of 0.5 by 6 to 80 by 80 square micrometer. The 2D simulations by implementing surface state models revealed the mechanism for the surface recombination current. Two device structures were proposed to diminish surface recombination current. Numerical simulations for type-II GaAsSb-InP base-collector (BC) junctions showed that conventional base "push-out" does not occur at high injection levels, and instead the electric field at the BC junction is reversed and an electron barrier at the base side evolves. The electron barrier was found to play an important role in the Kirk effect, and the electron tunnelling through the barrier delays the onset of the Kirk effect. This novel mechanism was supported by the measurement for GaAsSb/InP DHBTs with two base doping levels. The study also showed that the magnitude of the electric field at the BC junction at zero collector current directly affects onset of the Kirk effect. Finally, optimizations for the emitter, base and collector were carried out through 2D simulations. A thin InAlAs emitter, an (AI)GaAsSb compositionally graded base with band gap variance of 0.1eV, and a high n-type delta doping in the collector were proposed to simultaneously achieve high frequency performance, high Kirk current density and high breakdown voltage. Keywords. Heterojunction bipolar transistor; InP; GaAsSb; device simulation

Tao, Nick Gengming

232

Total dose effects on gate controlled lateral PNP bipolar junction transistors  

SciTech Connect

A gate controlled lateral PNP bipolar device has been designed in a commercial BiCMOS process to investigate its sensitivity to radiation-induced degradation. New experimental and simulated results concerning total dose effects are presented. The improved radiation hardness of this device working in its accumulation mode is shown. The influence of the gate potential during irradiation is studied as well as the effect of the gate potential on the degraded current characteristics.

Cazenave, P.; Fouillat, P.; Montagner, X. [Univ. of Bordeaux 1, Talence (France). Lab. IXL] [and others

1998-12-01

233

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

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

234

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

235

A high voltage silicon-on-insulator lateral insulated gate bipolar transistor with a reduced cell-pitch  

NASA Astrophysics Data System (ADS)

A high voltage (> 600 V) integrable silicon-on-insulator (SOI) trench-type lateral insulated gate bipolar transistor (LIGBT) with a reduced cell-pitch is proposed. The LIGBT features multiple trenches (MTs): two oxide trenches in the drift region and a trench gate extended to the buried oxide (BOX). Firstly, the oxide trenches enhance electric field strength because of the lower permittivity of oxide than that of Si. Secondly, oxide trenches bring in multi-directional depletion, leading to a reshaped electric field distribution and an enhanced reduced-surface electric-field (RESURF) effect. Both increase the breakdown voltage (BV). Thirdly, oxide trenches fold the drift region around the oxide trenches, leading to a reduced cell-pitch. Finally, the oxide trenches enhance the conductivity modulation, resulting in a high electron/hole concentration in the drift region as well as a low forward voltage drop (Von). The oxide trenches cause a low anode—cathode capacitance, which increases the switching speed and reduces the turn-off energy loss (Eoff). The MT SOI LIGBT exhibits a BV of 603 V at a small cell-pitch of 24 ?m, a Von of 1.03 V at 100 A/cm-2, a turn-off time of 250 ns and Eoff of 4.1×10-3 mJ. The trench gate extended to BOX synchronously acts as dielectric isolation between high voltage LIGBT and low voltage circuits, simplifying the fabrication processes.

Luo, Xiao-Rong; Wang, Qi; Yao, Guo-Liang; Wang, Yuan-Gang; Lei, Tian-Fei; Wang, Pei; Jiang, Yong-Heng; Zhou, Kun; Zhang, Bo

2013-02-01

236

Analysis of collector-emitter offset voltage of InGaP/GaAs composite collector double heterojunction bipolar transistor  

NASA Astrophysics Data System (ADS)

The Ebers-Moll-like terminal current expressions of a composite collector double heterojunction bipolar transistor (DHBT), which takes the recombination effect into account, have been formulated and an expression for collector-emitter offset voltage [VCE(offset)] has been derived. Factors affecting the VCE(offset) of a composite collector DHBT are investigated and good agreement between the calculated and reported experimental results is shown. Analytical results showed that the transmission coefficient of the base-collector (B-C) junction does not have a considerable effect on the VCE(offset), provided that the B-C junction is of good quality. Thus, despite its asymmetric structure, the VCE(offset) of an optimally designed composite collector DHBT could be as low as that of a conventional DHBT. Hence a composite collector DHBT with low saturation voltage and negligible VCE(offset) is possible if the two conditions: (i) good quality B-C junction, (ii) base transport factor, ?~1, are fulfilled.

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

2002-04-01

237

Stability study and effect of passivation on InP/InGaAs double heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

This work explores the thermal and bias stabilities of composite-collector double heterojunction bipolar transistors (CC-DHBTs) with i-InGaAs/n+-InP in the collector layer, in the temperature range of 300-400 K. Both V-shaped behaviors (observed in dc current gain ? against collector current IC and in offset voltage VCE,offset against base current IB plot) of the asymmetric CC-DHBT are studied simultaneously. At high IC, the devices of interest improve the dc current gain temperature stability relative to most HBTs described in the literature. Additionally, unlike that of the abrupt DHBTs in the literature, the ? of the CC-DHBTs is independent of VCB, revealing that the effect of the conduction-band barrier in the base-collector junctions may have been eliminated. An analytical expression for the variation in VCE,offset with IB has been developed. Additionally, unlike that of the unpassivated and SiNx-passivated devices, the ? of the sulfur-treated device is fairly constant over five decades of IC. The difference among these variously treated devices is striking. X-ray photoelectron spectroscopy was adopted to examine InGaAs surfaces that were (NH4)2Sx and SiNx passivated. The results reveal that passivation effectively suppresses the oxidation of As.

Lin, Yu-Shyan; Jou, Yu-Jeng; Huang, Pin-Chun

2009-02-01

238

Effect of Mg ionization efficiency on performance of Npn AlGaN/GaN heterojunction bipolar transistors  

SciTech Connect

A drift-diffusion transport model has been used to examine the performance capabilities of AlGaN/GaN Npn heterojunction bipolar transistors (HBTs). Simulations using experimental mobility and lifetime reported in the literature closely reproduce the Gummel plot from the GaN-based HBT structure recently demonstrated. Numerical results have been explored to study the effect of the p-type Mg doping and its incomplete ionization in the base. The high base resistance induced by the deep acceptor level is found to be the cause of limiting current gain values. Increasing the operating temperature of the device activates more carriers in the base. An improvement of the simulated current gain by a factor of 2-4 between 25 and 300 degree sign C agrees well with the reported experimental results. A preliminary analysis of high-frequency characteristics indicates substantial progress of predicted rf performances by operating the device at higher temperature due to a reduced extrinsic base resistivity. (c) 2000 American Institute of Physics.

Monier, C. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Pearton, S. J. [Department of Materials Science and Engineering, University of Florida, Gainesville, Florida 32611 (United States); Chang, P. C. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Baca, A. G. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Ren, F. [Department of Chemical Engineering, University of Florida, Gainesville, Florida 32611 (United States)

2000-05-22

239

Effect of Mg ionization efficiency on performance of Npn AlGaN/GaN heterojunction bipolar transistors  

SciTech Connect

A drift-diffusion transport model has been used to examine the performance capabilities of AlGaN/GaN Npn heterojunction bipolar transistors (HBTs). The Gummel plot from the first GaN-based HBT structure recently demonstrated is adjusted with simulation by using experimental mobility and lifetime reported in the literature. Numerical results have been explored to study the effect of the p-type Mg doping and its incomplete ionization in the base. The high base resistance induced by the deep acceptor level is found to be the cause of limiting current gain values. Increasing the operating temperature of the device activates more carriers in the base. An improvement of the simulated current gain by a factor of 2 to 4 between 25 and 300 C agrees well with the reported experimental results. A preliminary analysis of high frequency characteristics indicates substantial progress of predicted rf performances by operating the device at higher temperature due to a reduced extrinsic base resistivity.

MONIER,C.; PEARTON,S.J.; CHANG,PING-CHIH; BACA,ALBERT G.

2000-03-10

240

DC modeling and characterization of AlGaAs/GaAs heterojunction bipolar transistors for high-temperature applications  

SciTech Connect

There is currently a demand for active electronic devices operating reliably over wide range of temperatures. Potential applications for the high-temperature devices and integrated circuits are in the areas of jet engine and control instrumentation for nuclear power plants. Here, the large signal dc characteristics of AlGaAs/GaAs heterojunction bipolar transistors (HBT) at high temperatures (27--300 C) are reported. A high-temperature SPICE model is developed which includes the recombination-generation current components and avalanche multiplication which become extremely important at high temperatures. The effect of avalanche breakdown is also included to model the current due to thermal generation of electron/hole pairs causing breakdown at high temperatures. A parameter extraction program is developed used to extract the model parameters of HBT's at different temperatures. Fitting functions for the model parameters as a function of temperature are developed. These parameters are then used in the SPICE Ebers-Moll model for the dc characterization of the HBT at any temperature between (27--300 C).

Dikmen, C.T.; Dogan, N.S.; Osman, M.A. (Washington State Univ., Pullman, WA (United States). School of Electrical Engineering and Computer Science)

1994-02-01

241

Annealing neutron damaged silicon bipolar transistors: Relating gain degradation to specific lattice defects  

NASA Astrophysics Data System (ADS)

Isochronal anneal sequences have been carried out on pnp and npn transistors irradiated with fast neutrons at a variety of fluences. The evolution of base and collector currents was utilized to characterize the annealing behavior of defects in both the emitter-base depletion region and the neutral base. Various annealing biases, theoretical modeling, as well as previous deep level transient spectroscopy (DLTS) data, were used to assign the relative magnitude of each of the important defects to the total recombination current. We find that donor-vacancy pairs in the neutral n-type base of our pnp transistors are responsible for about 1/3 of the postdamage lifetime degradation, while the remaining recombination currents can be largely attributed to a cluster-related divacancylike defect which has no shallow state DLTS emission peak. This latter defect anneals gradually from 350 to 590 K. Generation/recombination currents in the base-emitter junctions in both types of devices were found to anneal in a similar, gradual fashion, suggesting that this same cluster-related intrinsic lattice defect is also responsible for the large, damage-induced base currents.

Fleming, R. M.; Seager, C. H.; Lang, D. V.; Campbell, J. M.

2010-09-01

242

Evolution of the MOS transistor - From conception to VLSI  

NASA Astrophysics Data System (ADS)

Historical developments of the MOSFET during the last 60 years are reviewed, from the 1928 patent disclosures of the field-effect conductivity modulation concept and the semiconductor triode structures proposed by Lilienfeld to the 1947 Shockley-originated efforts which led to the laboratory demonstration of the modern silicon MOSFET in 1960. A survey is then made of the milestones of the past 30 years leading to the latest submicron silicon logic CMOS and BICMOS (bipolar-junction transistor CMOS combined) arrays and the three-dimensional and ferroelectric extensions of Dennard's one-transistor DRAM cell. The status of the submicron lithographic technologies is summarized. Future trends of memory cell density and logic gate speed are projected. Comparisons of the switching speed of the silicon MOSFET with that of silicon bipolar and GaAs FETs are reviewed.

Sah, Chih-Tang

1988-10-01

243

A novel high-voltage light punch-through carrier stored trench bipolar transistor with buried p-layer  

NASA Astrophysics Data System (ADS)

A novel high-voltage light punch-through (LPT) carrier stored trench bipolar transistor (CSTBT) with buried p-layer (BP) is proposed in this paper. Since the negative charges in the BP layer modulate the bulk electric field distribution, the electric field peaks both at the junction of the p base/n-type carrier stored (N-CS) layer and the corners of the trench gates are reduced, and new electric field peaks appear at the junction of the BP layer/N- drift region. As a result, the overall electric field in the N- drift region is enhanced and the proposed structure improves the breakdown voltage (BV) significantly compared with the LPT CSTBT. Furthermore, the proposed structure breaks the limitation of the doping concentration of the N—CS layer (NN—CS) to the BV, and hence a higher NN—CS can be used for the proposed LPT BP-CSTBT structure and a lower on-state voltage drop (Vce(sat)) can be obtained with almost constant BV. The results show that with a BP layer doping concentration of NBP = 7 × 1015 cm-3, a thickness of LBP = 2.5 ?m, and a width of WBP = 5 ?m, the BV of the proposed LPT BP-CSTBT increases from 1859 V to 1862 V, with NN—CS increasing from 5 × 1015 cm-3 to 2.5 × 1016 cm-3. However, with the same N--drift region thickness of 150 ?m and NN—CS, the BV of the CSTBT decreases from 1598 V to 247 V. Meanwhile, the Vce(sat) of the proposed LPT BP-CSTBT structure decreases from 1.78 V to 1.45 V with NN—CS increasing from 5 × 1015 cm-3 to 2.5 × 1016 cm-3.

Zhang, Jin-Ping; Li, Ze-Hong; Zhang, Bo; Li, Zhao-Ji

2012-06-01

244

A Base-Emitter Self-Aligned Multi-Finger Si1-xGex/Si Power Heterojunction Bipolar Transistor  

NASA Astrophysics Data System (ADS)

With a crystal orientation dependent on the etch rate of Si in KOH-based solution, a base-emitter self-aligned large-area multi-finger configuration power SiGe heterojunction bipolar transistor (HBT) device (with an emitter area of about 880 ?m2) is fabricated with 2 ?m double-mesa technology. The maximum dc current gain is 226.1. The collector-emitter junction breakdown voltage BVCEO is 10 V and the collector-base junction breakdown voltage BVCBO is 16 V with collector doping concentration of 1×1017 cm-3 and thickness of 400 nm. The device exhibited a maximum oscillation frequency fmax of 35.5 GHz and a cut-off frequency fT of 24.9 GHz at a dc bias point of IC = 70 mA and the voltage between collector and emitter is VCE = 3 V. Load pull measurements in class-A operation of the SiGe HBT are performed at 1.9 GHz with input power ranging from 0 dBm to 21 dBm. A maximum output power of 29.9 dBm (about 977 mW) is obtained at an input power of 18.5 dBm with a gain of 11.47 dB. Compared to a non-self-aligned SiGe HBT with the same heterostructure and process, fmax and fT are improved by about 83.9% and 38.3%, respectively.

Xue, Chun-Lai; Yao, Fei; Shi, Wen-Hua; Cheng, Bu-Wen; Wang, Hong-Jie; Yu, Jin-Zhong; Wang, Qi-Ming

2007-07-01

245

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

246

1 Watt, 65% PAE K-band AlGaAs\\/GaAs heterojunction bipolar transistors using emitter air-bridge technology  

Microsoft Academic Search

We report on the state-of-the-art power performance of K-band AlGaAs\\/GaAs heterojunction bipolar transistors (HBTs) which had emitter air-bridges to connect individual emitter fingers within the unit cells to reduce the emitter inductance and device thermal impedance. A 8×(1.6×30) ?m2 HBT achieved 1.04 W CW output power and 65.7% power-added efficiency with 6.3 dB associated gain at 20 GHz. The maximum

Hin-Fai Chau; Darrell Hill; Ron Yarborough; Tae Kim

1997-01-01

247

1 Watt, 65% PAE K-band AlGaAs\\/GaAs heterojunction bipolar transistors using emitter air-bridge technology  

Microsoft Academic Search

We report on the state-of-the-art power performance of K-band AlGaAs-GaAs heterojunction bipolar transistors (HBTs) which had emitter air-bridges to connect individual emitter fingers within the unit cells to reduce the emitter inductance and device thermal impedance. A 8×(1.6×30) ?m2 HBT achieved 1.04 W CW output power and 65.7% power-added efficiency with 6.3 dB associated gain at 20 GHz. The maximum

Hin-Fai Chau; Darrell Hill; Ron Yarborough; Tae Kim

1997-01-01

248

A New Voltage between Collector and Emitter (VCE) Sensing Scheme for Short-Circuit Withstanding Capability of the Insulated Gate Bipolar Transistor  

NASA Astrophysics Data System (ADS)

A new protection circuit employing a voltage between collector and emitter (VCE) sensing scheme for the short-circuit withstanding capability of insulated gate bipolar transistors (IGBTs) is proposed and verified on the basis of two-dimensional simulation and experimental results. Because the current path between the gate and the collector can be successfully eliminated in the proposed protection circuit, power consumption can be reduced and gate input impedance can be increased. The experimental results show that the proposed protection circuit can adjust the current saturation level of IGBTs and the short-circuit withstanding capability can be significantly enhanced.

Jeon, Byung-Chul; Ji, In-hwan; Ha, Min-Woo; Han, Min-Koo; Choi, Yearn-Ik

2004-04-01

249

Surface passivation effects of As sub 2 S sub 3 glass on self-aligned AlGaAs/GaAs heterojunction bipolar transistors  

SciTech Connect

A recently developed As{sub 2}S{sub 3} chemical treatment was used to passivate the perimeters of self-aligned heterojunction bipolar transistors (HBTs). The As{sub 2}S{sub 3} chemical treatment significantly lowered the base current resulting in a two order of magnitude reduction in the collector current density at which dc current gain was observed ({beta}=1). No degradation with time has been observed in the electrical characteristics of the chemically treated HBTs. This absence of degradation is attributed to the impermeability to oxygen of the As{sub 2}S{sub 3} glass which coats the perimeter of the HBT after chemical treatment.

Chuang, H.L.; Carpenter, M.S.; Melloch, M.R.; Lundstrom, M.S. (School of Electrical Engineering, Purdue University, West Lafayette, Indiana 47907 (USA)); Yablonovitch, E.; Gmitter, T.J. (Bell Communications Research, Navesink Research Center, Red Bank, NJ (USA))

1990-11-12

250

A Q-band Low Phase Noise Voltage Controlled Oscillator Using Balanced ?-Feedback in 2-?m GaAs HBT Process  

Microsoft Academic Search

A Q-band low phase noise voltage controlled oscillator (VCO) using balanced ?-feedback with 2-?m GaAs heterojunction bipolar transistor (HBT) process is reported in this paper. The VCO features a phase noise of -105.5 dBc\\/Hz at 1-MHz offset, and a tuning frequency of from 41.2 to 42.1 GHz with a maximum output power of -9 dBm. The differential outputs are also

Chi-Hsein Lin; Kung-Hao Liang; Hong-Yeh Chang; Yi-Jen Chan; Chau-Ching Chiong; Eric Bryerton

2007-01-01

251

Identification of degradation mechanisms in a bipolar linear voltage comparator through correlations of transistor and circuit response  

SciTech Connect

The input bias current (I{sub IB}) of the National LM111 voltage comparator exhibits a non-monotonic response to total dose irradiations at various dose rates. At low total doses, below 100 krad(SiO{sub 2}), increased I{sub IB} is due primarily to gain degradation in the circuit's input transistors. At high total doses, above 100 krad(SiO{sub 2}), I{sub IB} shows a downward trend that indicates the influence of compensating circuit mechanisms. Through correlation of transistor and circuit response, the transistors responsible for these compensating mechanisms are identified. Non-input transistors in the circuit's input stage lower the emitter-base operating point voltage of the input device. Lower emitter-base voltages reduce the base current supplied by the input transistors, causing a moderate recovery in the circuit response.

Barnaby, H.J.; Schrimpf, R.D.; Pease, R.L. [and others

1999-12-01

252

EHF Heterojunction Bipolar Transistors.  

National Technical Information Service (NTIS)

The purpose of this work is to determine if strained layers can be used to enhance performance for GaAs-based HBTs (Tasks 4 and 5), we have investigated the use of InGaAs layers in the base and emitter cap layer. The purpose is to aid in formation of ohmi...

B. Bayraktaroglu T. Henderson

1990-01-01

253

Surface roughness in sulfur ion-implanted InP with molecular beam epitaxy regrown double-heterojunction bipolar transistor layers  

SciTech Connect

We report on deep ion-implantation of sulfur into InP substrates to replace the epitaxial subcollector layer of double-heterojunction bipolar transistors. Using optimized implantation conditions of 350 keV energy and 1x10{sup 15} cm{sup -2} dose, we achieved a subcollector sheet resistance of 15 {omega}/square. Under well-controlled regrowth conditions a root-mean-square roughness of 12 A is measured from DHBT epitaxial layers grown on implanted InP substrates, comparable to DHBT epitaxial layers grown on n{sup +} epiready unimplanted substrates. We observe a pronounced increase in surface roughness of epitaxial layer beyond a threshold ion dose, depending on implantation energy. Large-area DHBT devices result with sulfur-ion implanted subcollector shows similar characteristics compared to devices fabricated on n{sup +}-doped InP substrates.

Hu, T.-C.; Chang, M.F.; Weimann, Nils; Chen Jianxin; Chen, Y.-K. [Department of Electrical Engineering, University of California, Los Angeles, California 90095 (United States); Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974 (United States)

2005-04-04

254

Extraction of the InP/InGaAs metallic collector-up heterojunction bipolar transistor small-signal equivalent circuit  

NASA Astrophysics Data System (ADS)

An efficient technique for determining the small-signal equivalent-circuit model of a Metal collector-up Heterojunction Bipolar Transistor (C-up MHBT) is presented. The technique employs analytically derived expressions for direct calculation of HBT T-Model equivalent circuit element values in terms of the measured S-parameters. This approach avoids errors due to uncertainty in fitting to large, over determined equivalent circuits and does not require the use of test structures and extra measurement steps to evaluate parasitics. Physically realistic results are demonstrated under various biasing conditions for the n-p-n InP/InGaAs HBT with metallic collector up structure. The agreement between the measured and model-produced data is excellent over the large frequency range and for several polarizations conditions for devices.

Bourguiga, R.; Oudir, A.; Mahdouani, M.; Pardo, F.; Pelouard, J. L.

2008-06-01

255

A high frequency (20 kHz) power electronics reactive-current compensator with insulated gate bipolar transistors as semiconductor switches  

NASA Astrophysics Data System (ADS)

The principle, the power converter, and the pulse pattern generator of a high frequency power reactive-current compensation for the climination of the instantaneous reactive currents in a three phase grid are discussed. The time-averaged analysis of reactive currents was accomplished for a single phase supply, whereas the instantaneous analysis was accomplished for a three-phase grid. The instantaneous analysis shows that it is possible to build a reactive-current compensator without using an energy buffer (i.e., a compact converter). The topology of the compensator corresponds with a current-source inverter shortened at the dc side. The inverter of the compensator uses insulated gate bipolar transistors. The pulse pattern generator is a realtime device operating according to the formulas of the instantaneous analysis.

Deleijer, G. J. J.

1988-12-01

256

An Analysis of the Anomalous Dip in Scattering Parameter S11 of InGaP/GaAs Heterojunction Bipolar Transistors (HBTs)  

NASA Astrophysics Data System (ADS)

The anomalous dip in scattering parameter S11 of InGaP/GaAs heterojunction bipolar transistors (HBTs) is explained quantitatively. Our results show that for InGaP/GaAs HBTs, the input impedance can be represented by a “shifted” series RC circuit at low frequencies and a “shifted” parallel RC circuit at high frequencies. The appearance of the anomalous dip of S11 in a Smith chart is caused by this inherent ambivalent characteristic of the input impedance. It is found that under constant collector-emitter voltage (VCE), an increase of base current (which corresponds to a decrease of base-emitter resistance and an increase of transconductance) enhances the anomalous dip. In addition, the anomalous dip in S11 of InGaP/GaAs HBTs can also be interpreted in terms of poles and zeros.

Lin, Yo-Sheng; Lu, Shey-Shi

2004-06-01

257

All-silicon nonlinear transmission line integrated into a Si\\/SiGe heterostructure bipolar transistor process  

Microsoft Academic Search

Summary form only given. Nonlinear Transmission Lines (NLTL) have been fabricated so far on GaAs substrates only. Recently, we were able to demonstrate a working nonlinear transmission line for the first time on high resistivity silicon proving the applicability of the NLTL concept to silicon millimeter wave integrated circuits (SIMMWICs). We have significantly improved our previous results by integrating the

M. Birk; D. Behammer; H. Schumacher

2000-01-01

258

AlGaAs/InGaAsN/GaAs PnP double heterojunction bipolar transistor  

SciTech Connect

The authors have demonstrated a functional MOCVD-grown AlGaAs/InGaAsN/GaAsPnP DHBT that is lattice matched to GaAs and has a peak current gain ({beta}) of 25. Because of the smaller bandgap (E{sub g}=1.20eV)of In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} used for the base layer, this device has a low V{sub ON} of 0.79 V, 0.25 V lower than in a comparable Pnp AlGaAs/GaAs HBT. The BV{sub CEO} is 12 V, consistent with its GaAs collector thickness and doping level.

Chang, P.C.; Baca, A.G.; Li, N.Y.; Sharps, P.R.; Hou, H.Q.; Laroche, J.R.; Ren, F.

2000-01-11

259

GaInP\\/GaAs collector-up tunneling-collector heterojunction bipolar transistors (Cup TC-HBTs): optimization of fabrication process and epitaxial layer structure for high-efficiency high-power amplifiers  

Microsoft Academic Search

This paper describes a novel heterojunction bipolar transistor (HBT) structure, the collector-up tunneling-collector HBT (C-up TC-HBT), that minimizes the offset voltage VCE,sat and the knee voltage Vk. In this device, a thin GaInP layer is used as a tunnel barrier at the base-collector (BC) junction to suppress hole injection into the collector, which results in small VCE,sat. Collector-up configuration is

Kazuhiro Mochizuki; Rebecca J. Welty; Peter M. Asbeck; Charles R. Lutz; Roger E. Welser; Susan J. Whitney; Noren Pan

2000-01-01

260

Very-high fT and fmax silicon bipolar transistors using ultra-high-performance super self-aligned process technology for low-energy and ultra-high-speed LSI's  

Microsoft Academic Search

Very-high fT (up to 50 GHz) and fmax (up to 70 GHz) silicon bipolar transistors have been developed using Ultra-high-performance Super Self-aligned process Technology (USST). This technology is characterized by drastically-scaled lateral dimensions and shallow, heavily-doped extrinsic base structures. USST greatly reduces base-collector junction capacitance and base resistance, and hence makes fmax about twice as large as SST1C technology without

Mamoru Ugajin; Jun-ichi Kodate; Y. Kobayashi; S. Konaka; T. Sakai

1995-01-01

261

Low-frequency noise and random telegraph signal noise in SiGe:C heterojunction bipolar transistors: impact of carbon concentration  

NASA Astrophysics Data System (ADS)

We have investigated the influence of carbon concentration on the low frequency noise (LFN) of Si/SiGe:C Heterojunction Bipolar Transistors (HBTs). The HBTs are supplied by ST-Microelectronics Crolles and are based on a 0.13 ?m BiCMOS technology. Three types of transistors were studied; they only differ by the amount of carbon incorporated. When carbon is incorporated, representative noise spectra of the input current spectral density, SiB, show important generation-recombination (G-R) components, while no such components are observed in carbon free transistors. When the 1/f noise component is unambiguously observed, the associated figure of merit KB has a very good value close to 4.10-10 ?m2. In this paper we focus on the analysis of the G-R components associated with the presence of the carbon. Most of the observed Lorentzians are associated with Random Telegraph Signal (RTS) noise. No RTS noise is found in carbon free devices. The RTS noise appears to be due to electrically active defects formed by the addition of carbon, typically observed for concentrations above the bulk solid solubility limit in silicon. The RTS noise, amplitude ?IB and the mean pulse widths (tH, tL), are analyzed as a function of bias voltage and temperature. The RTS amplitude is found to scale with the base current and to decrease exponentially with temperature, independently of the carbon concentration. The mean pulse widths are found to decrease rapidly with bias voltage, as 1/exp(qVBE/kT) or stronger. Our results confirm that electrically active C-related defects are localized in the base-emitter junction, and the RTS amplitude is explained by a model based on voltage barrier height fluctuations across the base-emitter junction induced by trapped carriers in the space charge region. The observed bias dependence of mean pulse widths seems to indicate that two capture processes are involved, electron and hole capture. These C-related defects behave like recombination centers with deep energy levels rather than electron or hole traps involving trapping-detrapping process.

Raoult, Jeremy; Delseny, Colette; Pascal, Fabien; Marin, Mathieu; Deen, M. Jamal

2007-07-01

262

Direct observation of lifetime killing defects in 4H SiC epitaxial layers through spin dependent recombination in bipolar junction transistors  

NASA Astrophysics Data System (ADS)

We have identified a magnetic resonance spectrum associated with minority carrier lifetime killing defects in device quality 4H SiC through magnetic resonance measurements in bipolar junction transistors using spin dependent recombination (SDR). The SDR spectrum has nine distinguishable lines; it is, within experimental error, essentially isotropic with four distinguishable pairs of side peaks symmetric about the strong center line. The line shape is, within experimental error, independent of bias voltage and recombination current. The large amplitude and spacing of the inner pair of side peaks and three more widely separated pairs of side peaks are not consistent with either a simple silicon or carbon vacancy or a carbon or silicon antisite. This indicates that the lifetime killing defect is not a simple defect but a defect aggregate. The spectrum is consistent with a multidefect cluster with an electron spin S=12. (The observed spectrum has not been reported previously in the magnetic resonance literature on SiC.) A fairly strong argument can be made in terms of a first order model linking the SDR spectrum to a divacancy or possibly a vacancy/antisite pair. The SDR amplitude versus gate voltage is semiquantitatively consistent with a very simple model in which the defect is uniformly distributed within the depletion region of the base/collector junction and is also the dominating recombination center. The large relative amplitude of the SDR response is more nearly consistent with a Kaplan-Solomon-Mott-like model for spin dependent recombination than the Lepine model.

Cochrane, C. J.; Lenahan, P. M.; Lelis, A. J.

2009-03-01

263

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

264

A Monolithic SiGe Heterojunction Bipolar Transistor Gilbert Upconverter with Inductor-Capacitor Current Mirror Load and Lumped-Element Rat-Race Balun  

NASA Astrophysics Data System (ADS)

A 5.2 GHz upconversion Gilbert mixer with single-ended intermediate frequency (IF), local oscillator (LO), and RF ports is demonstrated using 0.35 ?m SiGe heterojunction bipolar transistor (HBT) technology. The upconverter has a single-ended IF port. In addition, a lumped-element rat-race hybrid is inserted in the LO input stage to maintain balanced LO signals. The physics of the lumped-element rat-race is discussed in this paper. A passive LC current mirror is used to convert the mixer’s differential outputs into a single-ended output and double the output current. The design methodology of the LC current mirror and a new approach to improve the power gain with the output buffer are developed in this paper. The fully matched Gilbert upconverter has the conversion gain of -1 dB, OP1 dB of -10 dBm and OIP3 of 6 dBm when input IF=300 MHz, LO=4.9 GHz and output RF=5.2 GHz. The LO-IF isolation is -36 dB and the LO-RF isolation is -39 dB. The supply voltage is 3.3 V, the current consumption is 11.5 mA, and the die size is 0.98× 0.83 mm2 with six integrated on-chip inductors.

Wu, Tzung?Han; Meng, Chinchun; Wu, Tse?Hung; Huang, Guo?Wei

2006-08-01

265

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

NASA Astrophysics Data System (ADS)

InP-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-aligned emitter-base process and nonalloyed metallization of the emitter, base and collector ohmic contacts. The fabricated 2× 10 ?m2 emitter HBT exhibited a maximum current gain of 40. The maximum cutoff frequencies of this HBT were measured to be fT=79 GHz and fmax=143 GHz at IC=19 mA and VCE=1.5 V, respectively. An RFPD was fabricated using the base-collector junction layers of the HBT based on the selective wet chemical etching characteristics of InP and InGaAs layers. The fabricated RFPD showed a 37% increased optical responsivity of 0.48 A/W compared to the fabricated surface-illuminated photodiode using the same photoreceiver epitaxial layer. The full width at half maximum (FWHM) of the fabricated RFPD was determined to be 24 ps using the standard 50 ? system load. The fabricated three-stage transimpedance amplifier (TIA) showed a transimpedance gain of 46 dB? and a -3 dB bandwidth of 12 GHz. The fabricated monolithic RFPD/HBT photoreceiver has demonstrated a -3 dB optical bandwidth of 6.9 GHz.

Lee, Bangkeun; Yang, Kyounghoon

2004-04-01

266

Low-Turn-on-Voltage Heterojunction Bipolar Transistors with a C-Doped InGaAsSb Base Grown by Metalorganic Chemical Vapor Deposition  

NASA Astrophysics Data System (ADS)

We demonstrate the low-turn-on-voltage InP-based heterojunction bipolar transistors (HBTs) with a C-doped InGaAsSb base grown by metalorganic chemical vapor deposition. As the solid In content of InGaAsSb increases, not only the near-band-edge emission peak energy in photoluminescence spectra of the InGaAsSb film but also the turn-on base--emitter voltage of the HBT with an InGaAsSb base decrease. These results are attributed to the reduction of the InGaAsSb band gap with the increase of solid In content. We obtain the turn-on voltage of 0.35 V at collector current density of 1 A/cm2 in the HBT with a In0.22Ga0.78As0.73Sb0.27 base, which is one of the lowest turn-on voltages ever reported.

Hoshi, Takuya; Sugiyama, Hiroki; Yokoyama, Haruki; Kurishima, Kenji; Ida, Minoru

2012-04-01

267

Heavily carbon-doped p-type InGaAs grown by gas source molecular beam epitaxy for application to heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

The growth and characteristics of ultrahigh carbon-doped p-type InGaAs lattice matched to InP by gas source molecular beam epitaxy (GSMBE) using carbon tetrabromide (CBr4) as a doping source was investigated. The effects of growth temperature, group V supply pressure and CBr4 supply pressure on the composition, hole mobility and concentration of carbon-doped InGaAs were studied. The dependence of hydrogen passivation effect on different AsH3 supply pressure and different growth temperature were researched. Ultrahigh net hole concentration and room-temperature mobility of 1×1020 cm-3 and 45 cm2/V s, respectively, were achieved without any postgrowth annealing. Mobility of the ultrahigh carbon-doped InGaAs using CBr4 compared favorably to those of CBE grown carbon-doped InGaAs using CBr4 and molecular beam epitaxy grown beryllium (Be)-doped InGaAs grown at low temperature. The highly carbon-doped InGaAs layers grown by GSMBE using CBr4 as a doping source were used for the growth of high performance, highly carbon-doped base InP/InGaAs heterojunction bipolar transistor epitaxial layer structures.

Xu, Anhuai; Qi, Ming; Zhu, Fuying; Sun, Hao; Ai, Likun

2007-04-01

268

Controlled-Avalanche Superlattice Transistor.  

National Technical Information Service (NTIS)

A novel bipolar avalanche transistor is proposed. Controlled avalanche and large current output over a significant bias region is achieved by incorporating a staircase multiplication region at the base-collector junction. The III-V materials choice, devic...

P. K. Bhattacharya A. Chin K. S. Seo

1987-01-01

269

The characteristics and simulation of photo-bidirectional negative resistance transistor (PBNRT)  

Microsoft Academic Search

The bi-directional negative resistance transistor (BNRT) is an integrated device composed of two npn longitudinal bipolar transistors with common base and collector as well as an npn lateral bipolar transistor with the same base. We can get S type negative resistance characteristics between the two emitter terminals of both longitudinal transistors E1 and E2. By photosensitizing the BNRT, we have

Wei-Lian Guo; Xiao-Yun Li; Ping-Juan Niu; Shi-Lin Zhang; Tai-Shan Mo

2004-01-01

270

Bipolar trends  

SciTech Connect

The development of bipolar technology in recent years is reviewed, and trends for future development are projected. The developments clearly point to three salient features of today's advanced bipolar transistors, namely i) self-aligned structure, ii) deep-trench isolation, and iii) polysilicon emitter contact. Both i) and ii) allow advanced bipolar devices to have much higher circuit density and lower power-delay product than without these features. The polysilicon emitter contact allows bipolar devices to be scaled down vertically without suffering from problems of insufficient current gain or low emitter-collector punchthrough voltage. It is clear that while progress will continue in scaling the familiar high-speed ECL logic and memory, the integration level of these very high-speed chips is severely limited by the accompanied power dissipation. One seemingly promising and yet relatively unexplored direction is to increase the integration level by taking advantage of circuits with much lower power-delay product than ECL, such as NTL, TTL, CML, and MTL to improve the functional throughput. The technology challenges as well as the potential of submicrometer bipolar technology are also discussed.

Ning, T.H.; Tang, D.D.

1986-12-01

271

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.

272

Quantum-well resonant-tunneling transistors  

Microsoft Academic Search

The authors demonstrate bipolar resonant-tunneling transistors and propose unipolar transistors which are formed by making direct contact with the quantum well of a resonant-tunneling diode structure. The characteristics of this resonant-tunneling hot electron transistor (RHET), known as the QuESTT (quantum excited-state tunneling transistor), are examined. Both digital and microwave applications for these devices are discussed

A. C. Seabaugh; W. R. Frensley; Y. Kao; J. N. Randall; M. A. Reed

1989-01-01

273

Variable Temperature High-Frequency Response of Heterostructure Transistors  

NASA Astrophysics Data System (ADS)

The development of high performance heterostructure transistors is essential for emerging opto-electronic integrated circuits (OEICs) and monolithic microwave integrated circuits (MMICs). Applications for OEICs and MMICs include the rapidly growing telecommunications and personal communications markets. The key to successful OEIC and MMIC chip sets is the development of high performance, cost-effective technologies. In this work, several different transistor structures are investigated to determine the potential for high speed performance and the physical mechanisms controlling the ultimate device operation. A cryogenic vacuum microwave measurement system has been developed to study the high speed operation of modulation doped field-effect transistors (MODFETs), doped channel metal insulator field-effect transistors (MISFETs), and metal semiconductor field-effect transistors (MESFETs). This study has concluded that the high field velocity and not the low field mobility is what controls high frequency operation of GaAs based field-effect transistors. Both Al_{rm x} Ga_{rm 1-x}As/GaAs and InP/In_{rm y}Ga _{rm 1-y}As heterostructure bipolar transistors (HBTs) have also been studied at reduced lattice temperatures to understand the role of diffusive transport in the Al_{rm x} Ga_{rm 1-x}As/GaAs HBT and nonequilibrium transport in the InP/In _{rm y}Ga_ {rm 1-y}As HBT. It is shown that drift/diffusion formulation must be modified to accurately estimate the base delay time in the conventional Al _{rm x}Ga_ {rm 1-x}As/GaAs HBT. The reduced lattice temperature operation of the InP/In_ {rm y}Ga_{rm 1-y}As HBT demonstrates extreme nonequilibrium transport in the neutral base and collector space charge region with current gain cut-off frequency exceeding 300 GHz, which is the fastest reported transistor to date. Finally, the MODFET has been investigated as a three-terminal negative differential resistance (NDR) transistor. The existence of real space transfer is confirmed by analyzing the dc and microwave characteristics of the MODFET. The data are shown to correlate very well with the theoretical predictions of tunneling real space transfer between the channel and donor layer.

Laskar, Joy

1992-01-01

274

Suppression of the burn-in effect in InGaP/GaAs heterojunction bipolar transistors by constant period of voltage stress  

NASA Astrophysics Data System (ADS)

Two significantly abrupt increases of dc current gain (?) at the opposite extremes of base-emitter voltages (Vbe) linked by a relatively slight increase of ? in the range of 1.25<=Vbe<=1.75 V are found in InGaP/GaAs heterojunction bipolar transistors (HBT's). It has been proved that the burn-in effect directly causes the second abrupt increase of ? occurring at Vbe>1.75 V instead of elsewhere. In addition, choosing Vbe>1.75 V, a higher base-emitter voltage results in a faster increase rate with improvement in current gain transient. Based on these observations, a constant period of voltage stress (CPVS) with Vbe=2.0 V and Vce=3.0 V for 5 min with a specific choice of Vbe>1.75 V (the voltage range corresponding to the second abrupt increase of ?) is thus applied to promote the electrical performance of HBT's. After applying a CPVS, the burn-in effect is substantially suppressed without showing any second abrupt increase of current gain. Although the current measured under both reverse and forward biases is greatly reduced for the base-emitter junction, a CPVS slightly degrades the electrical properties of a base-collector junction. Also, it has been proved that bulk recombination, rather than the surface recombination current, the base contact recombination, or the space-charge recombination, is the dominant base current component causing the burn-in effect. The electrical improvement of the base-emitter junction is due to the annihilation of H-related traps in the base region after a CPVS. Once H- ions form, we propose that these ions are too fast to drift toward the base-collector junction under the reverse bias of the base-collector voltage. After migration through the extrinsic base region, H- ions are supposed to be trapped near the base-collector space region, which results in the degradation of the base-collector junction after a CPVS.

Chong, Kwok-Keung; Chen, Hsun-Chin; Houng, Mau-Phon; Wang, Yeong-Her; Lin, Shr-Ting

2004-02-01

275

Effect of Oxidation using Ultraviolet Light and Ozone and Subsequent Nitridation using Electron Cyclotron Resonance Plasma on Gate Portion of GaAs Field-Effect Transistors  

NASA Astrophysics Data System (ADS)

A recess-gate-type n-channel depletion mode metal-semiconductor field-effect transistor (MESFET), a metal-oxide-semiconductor field-effect transistor (MOSFET) prepared by UV and ozone oxidation, and metal-insulator-semiconductor field-effect transistors (MISFETs) prepared by oxidation followed by nitrogen plasma treatment for different time durations with an electron cyclotron resonance system (oxinitridation) were fabricated using an ex-situ process and equally current controlled recessed wafers. The MISFETs, especially the longest-nitrided one, showed the highest pinch-off gate voltage (-1.5 V) and the highest peak transconductance (170 mS/mm) at a 0.9 V gate voltage. The MOSFET showed the largest drain current, whereas the longest-nitrided MISFET showed the smallest drain current, owing to the difference in applicable forward gate voltage. These were clearly confirmed with statistical data. The transconductance obtained reproduces that of our previous experiment, and its increase is due to the improvement of crystallographic order in the vicinity of the insulator/semiconductor interface. The different applicable gate voltage implies that the subsequent nitridation weakens the barrier effect of the oxidized layer. An AlGaAs layer, as the mother material for oxinitridation, improves it.

Seto, Hiroki; Fujino, Yuhki; Iiyama, Koichi; Takamiya, Saburo; Hisaka, Takayuki; Totsuka, Masahiro; Aihara, Yasuki

2006-06-01

276

Molecular beam epitaxial growth of metamorphic AlInSb/GaInSb high-electron-mobility-transistor structures on GaAs substrates for low power and high frequency applications  

SciTech Connect

We report on molecular beam epitaxial growth of AlInSb/GaInSb metamorphic high-electron-mobility-transistor structures for low power, high frequency applications on 4 in. GaAs substrates. The structures consist of a Ga{sub 0.4}In{sub 0.6}Sb channel embedded in Al{sub 0.4}In{sub 0.6}Sb barrier layers which are grown on top of an insulating metamorphic buffer, which is based on the linear exchange of Ga versus In and a subsequent exchange of As versus Sb. Precise control of group V fluxes and substrate temperature in the Al{sub 0.4}In{sub 0.6}As{sub 1-x}Sb{sub x} buffer is essential to achieve high quality device structures. Good morphological properties were achieved demonstrated by the appearance of crosshatching and root mean square roughness values of 2.0 nm. Buffer isolation is found to be >100 k{Omega}/{open_square} for optimized growth conditions. Hall measurements at room temperature reveal electron densities of 2.8x10{sup 12} cm{sup -2} in the channel at mobility values of 21.000 cm{sup 2}/V s for single-sided Te volume doping and 5.4x10{sup 12} cm{sup -2} and 17.000 cm{sup 2}/V s for double-sided Te {delta}-doping, respectively.

Loesch, R.; Aidam, R.; Kirste, L.; Leuther, A. [Fraunhofer Institute for Applied Solid-State Physics (IAF), Tullastrasse 72, 79108 Freiburg (Germany)

2011-02-01

277

Reliability Investigation of Low Noise GaAs FETs.  

National Technical Information Service (NTIS)

The objective of this program is to assess the reliability and operating life characteristics of low noise, small signal, microwave, n-channel, gallium arsenide (GaAs), metal epitaxial semiconductor field effect transistors (MESFETs) with a Schottky-barri...

L. S. Bowman W. Tarn

1981-01-01

278

BaF2/GaAs Electronic Components.  

National Technical Information Service (NTIS)

Metal insulator semiconductor field effect transistors (MISFETs), charge coupled devices (CCDs), and capacitors based on an epitaxial barium fluoride (BF2) insulator layer deposited directly onto a single crystal gallium arsenide (GaAs) substrate.

F. Santiago T. K. Chu

1994-01-01

279

Effect of post-growth cooling ambient on acceptor passivation in carbon-doped GaAs grown by metalorganic chemical vapor deposition  

SciTech Connect

The degree of unintentional hydrogen passivation of acceptors in heavily C-doped GaAs ([ital p][gt]10[sup 18] cm[sup [minus]3]) grown by metalorganic chemical vapor deposition has been found to be a strong function of post-growth cool-down ambient. The carbon concentration in the GaAs and the amount of AsH[sub 3] in the cool-down ambient are the most important factors affecting passivation. Carbon acceptors can be reactivated by annealing in N[sub 2], then repassivated by heating and re-cooling in an AsH[sub 3]/H[sub 2] or PH[sub 3]/H[sub 2] ambient. Secondary ion mass spectrometry analysis shows that the hydrogen concentration is significantly higher in a C-doped GaAs surface layer which is exposed to the cool-down ambient than in a layer which is buried beneath [ital n]-type GaAs. This result is consistent with observations in [ital n]-[ital p]-[ital n] heterojunction bipolar transistor structures, where the fraction of C acceptors passivated in the base region is found to be less than in a single layer grown under identical conditions. Be-doped GaAs grown by gas-source molecular beam epitaxy has also been heated and cooled in AsH[sub 3]-containing ambients, but no acceptor passivation is detectable by Hall effect measurements.

Stockman, S.A.; Hanson, A.W.; Jackson, S.L.; Baker, J.E.; Stillman, G.E. (Center for Compound Semiconductor Microelectronics and Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States))

1993-03-15

280

Properties of Metal-Semiconductor Field-Effect Transistors Fabricated on Carbon-Doped Semi-Insulating GaAs Crystal Grown by Liquid Encapsulated Czochralski Method  

NASA Astrophysics Data System (ADS)

Metal-semiconductor field-effect transistors (MESFETs) whose active layers were made by ion-implantation were fabricated on a new type of semi-insulating liquid-encapsulated Czochralski (LEC)-grown crystal doped with carbon. The short-channel effect was suppressed and transconductance (gm), drain conductance and breakdown voltage were improved by carbon doping. These improvements were deduced as being due to a reduction in leakage under the channel. No change in the frequency dependence of the gm was recognized. Thus, the doped carbon did not generate any observable traps by which the properties of MESFET were degraded.

Otoki, Yoohei; Watanabe, Masatoshi; Kuma, Shoji; Takahashi, Susumu; Onishi, Masaya; Kashiwa, Mikio

1993-09-01

281

Numerical simulation of the comparative electrical performance of the permeable base transistor, opposed gate-source transistor and heterostructure launched ballistic field effect transistor  

Microsoft Academic Search

Devices operate under large signal conditions. Thus large signal simulations are required. This is illustrated for the permeable base transistor, the heterostructure bipolar transistor, and the opposed source-gate transistor. There were a number of ground-breaking results during the course of this study. The most significant is that a simulation was developed that coupled the large signal two dimensional device behavior

H. L. Grubin; J. P. Kreskovsky; M. Meyyappan; B. J. Morrison

1990-01-01

282

Charge separation for bipolar transistors  

SciTech Connect

The role of net positive oxide trapped charge and surface recombination velocity on excess base current in BJTs is identified. Although the interaction of these two radiation-induced defects is physically complex, simple approaches for estimating these quantities from measured BJT characteristics are presented. The oxide charge is estimated using a transition voltage in the plot of excess base current vs. emitter bias. Two approaches for quantifying die effects of surface recombination velocity are described; the first measures surface recombination directly using a gated diode. The second estimates its effects using an intercept current that is easily obtained from the BJT itself. The results are compared to two-dimensional simulations and measurements made on test structures. The techniques are simple to implement and provide insight into the mechanisms and magnitudes of the radiation-induced damage in BJTs.

Kosier, S.L.; Schrimpf, R.D.; Wei, A.; Chai, F. (Univ. of Arizona, Tucson, AZ (United States)); Nowlin, R.N. (Phillips Lab./VTE, Albuquerque, NM (United States)); Fleetwood, D.M. (Sandia National Labs., Albuquerque, NM (United States)); DeLaus, M. (Analog Devices, Inc., Woburn, MA (United States)); Pease, R.L. (RLP Research, Albuquerque, NM (United States)); Combs, W.E. (NSWC-Crane, IN (United States))

1993-12-01

283

Investigation of carbon profiles for enhanced boron confinement and improved carrier transport in strained silicon germanium nanolayers for heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

This research covers a breadth of topics, in Chapters 1 through 7, ranging from the crystal lattice, to dopant diffusion in SiGe, to SiGe and SiGeC chemical vapor deposition, to the Si/SiGe and Si/SiGeC energy band structure, and NPN SiGeC HBT AC and DC characteristics. Chapters 8 and 9 contain the results of the research, which relates the film growth and carbon positioning to boron diffusion, sheet resistance, and device performance; specifically current gain, fmax, and noise figures of merit. The first objective of the dissertation was to investigate carbon doping profiles in nano-layers (?32 nm) of silicon germanium (Si1-xGe x), and provide an understanding of "remote carbon boron confinement" (RCBC), which is demonstrated to exploit the advantages of carbon to increase NPN HBT (heterojunction bipolar transistor) performance, reduce base resistance, and improve overall noise figures of merit. The second objective was to investigate the noise characteristics of this method compared to the standard method of placing carbon throughout the lattice, which is known as "uniform carbon boron confinement" (UCBC). The current technological development towards smaller and faster devices has forced engineers and scientists to look into materials other than silicon, but which are highly compatible. A natural choice is the Si1-xGe x alloy, since Ge is also a Group IV. Si1-xGex has the same lattice structure as Si, but its lattice constant is 4.2% larger (aSi = 0.543nm, aGe = 0.567nm), and the bandgap is less than that of Si (Eg_Si = 1.11eV, Eg_Ge = 0.67eV). This opens the possibility of bandgap, strain, and dopant diffusion engineering, all of which affect the material and electronic properties of devices. The primary benefit of carbon is to reduce the diffusion of boron in Si1-xGex thus keeping the base narrow for significantly reduced electron transit times and increased unity gain cutoff frequencies (fT). However the utilization of carbon reduces base conductivity and increases base recombination current, while reducing the built-in biaxial strain. This latter property may or may not be desirable, while the first two are not desirable having negative consequences for fmax and noise figures of merit such as NF min. Chapter 8 discusses portions of this research, which identified a first-to-be-published method for carbon doping of silicon germanium films, which enhances the carbon confinement of boron, significantly reduces film resistance by approximately 23%, and increases the NPN HBT device performance. Chapter 9 discusses the improvements in noise figures of merit for an NPN HBT, which arise from improved film qualities presented in the Chapter 8 discussion. This research also illustrates that the device performance figures of merit such as base resistance, current gain, and subsequent noise figures are significantly determined during the epitaxial film growth.

Enicks, Darwin Gene

284

GaAs microwave MOSFET's  

Microsoft Academic Search

GaAs microwave metal-oxide-semiconductor field-effect transistors (MOSFET's) with plasma-grown native oxides as gate insulator have been fabricated using a low-temperature magnetically controlled plasma-oxidation technique. A small-signal enhancement device with the gate length of 2.0 ľm has demonstrated useful unilateral power gains in the 2-8-GHz frequency range. A maximum frequency of oscillation in the enhancement device is 13 GHz. This is the

T. Mimura; K. Odani; N. Yokoyama; Y. Nakayama; M. Fukuta

1978-01-01

285

Ka-band IQ vector modulator employing GaAs HBTs  

NASA Astrophysics Data System (ADS)

The importance of high-performance, low-cost and millimeter-wave transmitters for digital communications and radar applications is increasing. The design and performance of a Ka-band balanced in-phase and quadrature-phase (I-Q) type vector modulator, using GaAs heterojunction bipolar transistors (HBTs) as switching elements, are presented. The balanced technique is used to remove the parasitics of the HBTs to result in near perfect constellations. Measurements of the monolithic microwave integrated circuit (MMIC) chip with a size of 1.89 × 2.26 mm2 demonstrate an amplitude error below 1.5 dB and the phase error within 3° between 26 and 40 GHz except for a singular point at 35.6 GHz. The results show that the technique is suitable for millimeter-wave digital communications.

Yuxiong, Cao; Danyu, Wu; Gaopeng, Chen; Zhi, Jin; Xinyu, Liu

2011-06-01

286

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

287

Sub10fJ ECL\\/68-\\/spl mu\\/A 4.7GHz divider ultra-low-power SiGe base bipolar transistors with a wedge-shaped CVD-SiO\\/sub 2\\/ isolation structure and a BPSG-refilled trench  

Microsoft Academic Search

Ultra-low-power SiGe base bipolar transistors with a wedge-shaped CVD-SiO 2 isolation structure and a boro-phosphosilicate glass (BPSG)-refilled isolation trench are presented. The SiGe base and a poly-Si\\/SiGe base contact were formed by selective growth in a self-aligned manner. The transistors have a very small collector capacitance (below 1 fF) and exhibit a high maximum oscillation frequency (30-65 GHz) at low

M. Kondo; K. Oda; E. Ohue; H. Shimamoto; M. Tanabe; T. Onai; K. Washio

1996-01-01

288

Reliability Study of GaAs FET.  

National Technical Information Service (NTIS)

The reliability of three types of low-noise GaAs field-effect transistor (FET or MESFET) was investigated. Types A and B incorporate Al Schottky-barrier gates; Type C has a 'gold' gate structure (Ti/Cr/Pt/Au). FETs were tested to determine the ability of ...

R. Lundgren

1978-01-01

289

Bipolar Disorder  

MedlinePLUS

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

290

Advances in the technology for the Permeable Base Transistor.  

National Technical Information Service (NTIS)

The GaAs permeable base transistor (PBT) is fabricated by using overgrowth to embed a polycrystalline, submicrometer-period tungsten (W) grating completely within a single crystal of n-type GaAs. Recent PBTs have experimentally demonstrated an extrapolate...

M. A. Hollis K. B. Nichols R. A. Murphy C. O. Bozler

1987-01-01

291

Highly p-typed superlattices consist of undoped InAs and carbon-doped GaAs layers  

NASA Astrophysics Data System (ADS)

The strained-layer-superlattice (SLS) consisting of undoped InAs and carbon-doped GaAs (GaAs:C) layers were successfully grown on InP substrates by LP-MOVPE. The grown superlattice shows the p-type conductivity with a hole concentration of 1×1019 cm-3 and Hall mobility of 70 cm2 V-1 s-1 at room temperature. The resistivity is low enough to be used as an electrically equivalent highly p-type InGaAs base layer of an InP/InGaAs heterojunction bipolar transistor (HBT). The High-Angle Annular Dark Field Scanning Transmission Electron Microscopy (HAADF STEM) images reveal that the InAs/GaAs:C superlattice has an interface more abrupt than the undoped InAs/GaAs superlattice. It is attributed to the suppressed In diffusion from InAs to GaAs due to carbon doping in GaAs.

Uchida, Kazuo; Kanaya, Heisuke; Imanishi, Hiroshi; Koizumi, Atushi; Nozaki, Shinji

2013-05-01

292

Metal-sulfur-based air-stable passivation of GaAs with very low surface-state densities  

SciTech Connect

An 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. (c) 2000 American Institute of Physics.

Ashby, Carol I. H. [Sandia National Laboratories, Albuquerque, New Mexico 87185-0603 (United States); Zavadil, Kevin R. [Sandia National Laboratories, Albuquerque, New Mexico 87185-0603 (United States); Baca, Albert G. [Sandia National Laboratories, Albuquerque, New Mexico 87185-0603 (United States); Chang, P.-C. [Sandia National Laboratories, Albuquerque, New Mexico 87185-0603 (United States); Hammons, B. E. [Sandia National Laboratories, Albuquerque, New Mexico 87185-0603 (United States); Hafich, M. J. [Sandia National Laboratories, Albuquerque, New Mexico 87185-0603 (United States)

2000-01-17

293

Push-push design extends bipolar frequency range  

NASA Astrophysics Data System (ADS)

In connection with reliability, performance, and economic considerations, the bipolar transistor has been found useful in the design of linear voltage-controlled oscillators with low FM noise and good stability. However, in single-transistor applications, the bipolar transistor cannot be operated above mid C-band. The employment of a push-push configuration makes it possible to extract power at twice the fundamental frequency. Thus, bipolar transistors can be used in voltage-controlled oscillators in the X-band. Attention is given to the schematic of a push-push oscillator, a 200-MHz push-push oscillator using 2N5108 transistors, the output power spectrum, and aspects of transistor selection.

Bender, J. R.; Wong, C.

1983-10-01

294

Effects of total-dose irradiation on gate-all-around (GAA) devices  

Microsoft Academic Search

The response of gate-all-around (GAA) MOS transistors to dose irradiation is quite different from that observed on other types of silicon-on-insulator (SOI) MOSFETs. In regular SOI MOSFETs, edge leakage increases substantially faster than the main transistor leakage upon creation of oxide charges due to the irradiation. The GAA MOSFET behaves in the opposite way; the shift of edge threshold voltage

Jean-Pierre Colinge; Akira Terao

1993-01-01

295

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

296

GaAs device passivation using sputtered silicon nitride  

Microsoft Academic Search

This letter describes the passivation of GaAs field-effect transistors (FET’s) using sputtered silicon nitride films. A low-power reactive sputtering process for silicon nitride film deposition was developed and applied to both metal-semiconductor FET (MESFET) and high electron mobility transistor (HEMT) passivation. It is shown that the shifts in the FET parameters such as threshold voltage, breakdown voltage, and transconductance, after

Edward Y. Chang; Gregory T. Cibuzar; James M. Vanhove; Rao M. Nagarajan; Krishna P. Pande

1988-01-01

297

1,800 V Bipolar-Mode MOSFETs (IGBT),  

National Technical Information Service (NTIS)

Adopting the silicon wafer direct-bonding (SDB) technique, Toshiba has developed 1,800 V bipolar-mode MOSFETs (metal oxide semiconductor field effect transistors). The SDB technique, which eliminates the problems accompanying conventional epitaxy, easily ...

A. Nakagawa K. Imamura K. Furukawa

1987-01-01

298

High-frequency equivalent circuit of GaAs FETs for large-signal applications  

Microsoft Academic Search

The application of GaAs field effect transistors in digital circuits requires a valid description by an equivalent circuit at all possible gate and drain bias voltages for all frequencies from DC up to the gigahertz range. An equivalent circuit is presented which takes into account the gate current of positively biased transistors as well as the symmetrical nature of the

Manfred Berroth; Roland Bosch

1991-01-01

299

Advancements in the gallium arsenide/nickel aluminum material system and its potential for device applications: Progress towards the realization of a metal base transistor  

NASA Astrophysics Data System (ADS)

The concept of a metal base transistor is not a new one. In 1960, Carver A. Mead published a paper proposing a tunnel-emission amplifier comprised of metal-insulator-metal-insulator-metal structure in which the two insulator layers are thin barriers that produce tunnel-effect transmission of electrons between the metal layers. The middle metal layer would be thin with respect to the electronic mean free path in it. This structure would be capable of power gain in an analogous way to a conventional bipolar transistor. However, the realization of such a device was hampered by two problems. First, the large quantum mechanical reflection of electrons at the collector barrier of the device prohibited a large gain-a device physics problem. Second, the chosen material system, aluminum metal layers and oxidized aluminum layers (Al/Alsb2Osb3) was less than ideal-a materials problem. Oxide non-uniformity and non-ideal band offsets kept the device from satisfactory performance. In this thesis a different approach to realizing a practical metal base hot electron transistor will be investigated. In this approach, Molecular Beam Epitaxy (MBE) will be used to grow structures consisting of both III-V (GaAs based) semiconductors and single-crystal metals composed of NiAl. The advantages to this new approach will be discussed with respect to overcoming both of the problems mentioned above. A brief review of hot electron transistors will be provided. A discussion of hot electron transistors will emphasize the device physics relevant to overcoming the problems associated with a simple semiconductor hot electron transistor that is structurally very similar to the first metal/oxide transistor proposed by Mead. The later part of this thesis will focus on the material science related to the realization of a metal base transistor-specifically, how NiAl and related alloys, can be successfully grown on lattice mismatched III-V semiconductor substrates and employed in hot electron structures. It is the advancements in materials research that will ultimately be responsible for the success in realizing a metal base transistor since the structure of the transistor will largely be dictated by the material system used to construct the device.

Weckwerth, Mark Vernon

300

Effects of total-dose irradiation on Gate-All-Around (GAA) devices  

SciTech Connect

The response of Gate-All-Around MOS transistors to dose irradiation is quite different from that observed on other types of Silicon-On-Insulator MOSFETs. Indeed, in regular SOI MOSFETs, edge leakage increases substantially faster than the main transistor leakage upon creation of oxide charges due to the irradiation. The GAA MOSFET behaves in the opposite way: the shift of edge threshold voltage upon creation of charges in the oxide is smaller than that of the main transistor. As a result, a kink develops in the subthreshold characteristics of regular SOI MOSFETs upon irradiation, while the original subthreshold of GAA devices disappears when the device is irradiated.

Colinge, J.P.; Terao, A. (Univ. Catholique de Louvain, Louvain-la-Nueve (Belgium))

1993-04-01

301

Bipolar Disorder  

MedlinePLUS

... mania or depression. They may also result from treatment for bipolar disorder. Other illnesses can make it hard ... psychotherapy, or "talk" therapy, can be an effective treatment for bipolar disorder. It can provide support, education, and ...

302

Bipolar Disorder  

MedlinePLUS

... be tied to their monthly menstrual cycle . How Is Bipolar Disorder Diagnosed? Most people with bipolar disorder can be helped — but a psychiatrist or psychologist must first diagnose the disorder. Sadly, many people with the condition are ...

303

Bipolar Disorder  

MedlinePLUS

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

304

Graphene transistors  

Microsoft Academic Search

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

Frank Schwierz

2010-01-01

305

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

306

A bipolar pulse tester for semiconductor devices  

Microsoft Academic Search

The design and construction of a high voltage pulse generator suitable for bipolar pulse testing of semiconductor devices is described. The apparatus uses field effect transistors as the switching elements in a multistage capacitor discharge circuit based on the Marx generator principle.

S. V. G. Vardigans; D. de Cogan

1986-01-01

307

Gallium nitride based transistors  

NASA Astrophysics Data System (ADS)

An overview is presented of progress in GaN electronic devices along with recent results from work at UCSB. From 1995 to 2001, the power performance of AlGaN/GaN high electron mobility transistors (HEMT) improved from 1.1 to 11 W mm-1, respectively. The disadvantage of the low thermal conductivity of the sapphire substrate was mitigated by flip-chip bonding onto AlN substrates, yielding large periphery devices with an output power of 7.6 W. A variety of HEMT amplifier circuits have been demonstrated. The first AlGaN/GaN heterojunction bipolar transistor (HBT) was demonstrated in 1998, with a current gain of about 3. By developing the technique of emitter regrowth, a current gain of 10 was achieved in both GaN BJTs and AlGaN/GaN HBTs. A common emitter current gain cutoff frequency of 2 GHz was measured. Critical issues involved in the growth of high quality AlGaN/(AlN)/GaN heterostructures and GaN:Mg by metal-organic chemical vapour deposition (MOCVD) and molecular beam epitaxy (MBE) and the device fabrication are discussed.

Xing, H.; Keller, S.; Wu, Y.-F.; McCarthy, L.; Smorchkova, I. P.; Buttari, D.; Coffie, R.; Green, D. S.; Parish, G.; Heikman, S.; Shen, L.; Zhang, N.; Xu, J. J.; Keller, B. P.; Den Baars, S. P.; Mishra, U. K.

2001-08-01

308

Performance Evaluation of Source Heterojunction Strained Channel Gate all around Nanowire Transistor  

NASA Astrophysics Data System (ADS)

A Gate All Around Nanowire Transistor (GAA NWT) which employs source heterojunction and strained channel is proposed which improves device characteristics. A quantum mechanical transport approach based on nonequilibrium Green's function (NEGF) method in the frame work of effective mass theory is employed in this analysis. We evaluate the variation of the threshold voltage, the subthreshold slope, ON and OFF state currents when channel length decreases. It is shown that the source heterojunction strained channel GAA NWT gives high performance transistors values of the scaled transconductance and ON current that are greater than conventional silicon GAA NWT. Furthermore, comparison of switching delay ?d and unity current gain frequency fT of the devices shows that the performance of source heterojunction strained channel GAA NWT is better than the conventional silicon GAA NWT.

Hosseini, Reza; Fathipour, Morteza; Faez, Rahim

309

Bipolar Disorder  

Microsoft Academic Search

This chapter reviews knowledge regarding the management of bipolar illness during pregnancy and in the postpartum (lactation)\\u000a period. The natural course of bipolar illness during pregnancy and postpartum is discussed. Additionally, the chapter reviews\\u000a information on the effects of medication exposure in utero and during lactation on the fetus and infant. General guidelines about treating bipolar disorder are given.

Lori L. Altshuler; Carol Kiriakos

310

Switching Transistor  

NASA Astrophysics Data System (ADS)

Westinghouse Electric Corporation's D60T transistors are used primarily as switching devices for controlling high power in electrical circuits. It enables reduction in the number and size of circuit components and promotes more efficient use of energy. Wide range of application from a popcorn popper to a radio frequency generator for solar cell production.

1981-01-01

311

Bipolar disorder  

Microsoft Academic Search

Bipolar disorder is a pathological disturbance of mood, characterized by waxing and waning manic, depressive and, sometimes distinctly mixed states. A diagnosis of bipolar disorder can only be made with certainty when the manic syndrome declares itself. Most individuals who are diagnosed with this disorder will experience both poles of the illness recurrently, but depressive episodes are the commonest cause

Gérard Emilien; Lucia Septien; Claudine Brisard; Emmanuelle Corruble; Michel Bourin

2007-01-01

312

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

313

Graphical design and iterative analysis of the DC parameters of GaAs FET's  

Microsoft Academic Search

Two-dimensional numerical solutions of Poisson's equation and the carrier continuity equation for the short-gate GaAS field-effect transistor structure have been used to predict device performance. However, a generally accepted simplified approach to FET design has not evolved. In this paper, a simplified design technique and an iterative device analysis procedure are presented for application to GaAs FET's with gate lengths

R. B. Fair

1974-01-01

314

Wideband impedance transformer for UHF power transistor time domain waveform measurement system  

Microsoft Academic Search

A wideband impedance transformer for an ultra high frequency power transistor periodic time domain waveform measurement system was developed. It matches the low impedance levels of a bipolar power transistor to the standard 50 ohm level at the measurement frequency as well as its harmonics. The determination of the transformer scattering parameters for error correction of the time domain measurement

Kari Lehtinen; Tapio Malmivaara; Markku Sipilae

1989-01-01

315

A completely monolithic sample\\/hold amplifier using compatible bipolar and silicon-gate FET devices  

Microsoft Academic Search

A monolithic sample\\/hold subsystem, including an integrated holding capacitor, which utilizes simultaneously fabricated bipolar transistors and silicon-gate FETs to achieve performance levels previously unattainable in a single chip design, will be discussed.

K. Stafford; R. Blanchard; P. Gray

1974-01-01

316

Solidphase reactions between (100) GaAs and thin-film refractory metals (Ti, Zr, V, Nb, Cr, Mo, and W)  

Microsoft Academic Search

Recently, there has been an increased interest in the applications of refractory metals as gate materials for the self aligned gate process in the fabrications of GaAs field effect transistors. In this study, we systematically investigated the thermally induced interface interactions between (100) GaAs substrates and thin films of refractory metals (Ti, Zr, V, Nb, Cr, Mo, and W). Depth

K. M. Yu; J. M. Jaklevic; E. E. Haller

1987-01-01

317

BEC transistor  

NASA Astrophysics Data System (ADS)

In the past decade, considerable efforts have been spent developing BEC based devices for applications such as fundamental research, precision measurements, and quantum information technology. These devices, capable of complex functionality, may be constructed from simple building blocks. New atom-optical components will enable researchers to build more elaborate integrated devices. One of the most important components of microelectronics is the transistor. We are proposing a device that shows behavior reminiscent of a transistor, which enables one to control a large number of atoms with a smaller number. This device utilizes three atom traps where the atoms in the left act as the source in a field effect transistor, the atoms in the middle act as the gate, and the right trap is the drain. When the middle trap is empty, atoms cannot tunnel from the left through the middle and in to the right, because the chemical potential in the middle trap is sufficiently smaller than that in the left or right to block tunneling. If a small number of atoms are placed in the middle, the device switches enabling tunneling from the left to the right. This tunneling is due to the fact that atom-atom interactions increase the chemical potential in the middle trap and remove the energy mismatch. We show that the number of atoms tunneling into the right can be much larger than the number of controlling atoms in the middle. Thus, the three trap structure demonstrates both absolute and differential gain, and that it can be used as an atomic transistor.

Stickney, James; Anderson, Dana; Zozulya, Alex

2006-05-01

318

Transistors Assessment  

NSDL National Science Digital Library

This brief assessment on transistors is intended to be used after students have completed the introductory activity on the topic, which may be located here. The assessment consists of 11 multiple choice and short answer questions. The other educational modules in this series can be found here. Instructors and students are encouraged to sign up with the Electron Technologies site here before starting to use these materials.

2012-10-08

319

1\\/f noise in advanced CMOS transistors  

Microsoft Academic Search

Complementary metal-oxide-semiconductor (CMOS) technology is dominant in the microelectronics industry for a wide range of applications, including analog, digital, RF, and sensor systems. The advantages of silicon CMOS technology compared to bipolar technology as well as transistors in other semiconductors is well-established. CMOS technology scaling has been a main drive for continuous progress in the silicon based semiconductor industry over

Yael Nemirovsky; Dan Corcos; Igor Brouk; Amikam Nemirovsky; Samir Chaudhry

2011-01-01

320

Bipolar disorder.  

PubMed

Bipolar disorder (manic-depressive illness) is a common, recurrent, and severe psychiatric disorder that affects 1% to 3% of the US population. The illness is characterized by episodes of mania, depression, or mixed states (simultaneously occurring manic and depressive symptoms). Bipolar disorder frequently goes unrecognized and untreated for many years without clinical vigilance. New screening tools have been developed to assist physicians in making the diagnosis. Fortunately, several medications are now available to treat the acute mood episodes of bipolar disorder and to prevent further episodes with maintenance treatment. PMID:11349478

Keck, P E; McElroy, S L; Arnold, L M

2001-05-01

321

Design of RF integrated circuits using SiGe bipolar technology  

Microsoft Academic Search

We report on design aspects and the implementation of radio-frequency integrated circuits using TEMIC's SiGe technology. The differences between the device parameters of silicon bipolar junction transistor and silicon germanium heterojunction bipolar transistor technology and their influence on IC design are discussed. Design and measurement results of RFICs, including low noise amplifier, power amplifier, and single-pole, double-throw antenna switch for

R. Gotzfried; Frank Beisswanger; Stephan Gerlach

1998-01-01

322

GaAs MOSFET using InAlP native oxide as gate dielectric  

Microsoft Academic Search

GaAs metal-oxide-semiconductor field-effect transistors (MOSFETs) using wet thermally oxidized InAlP as the gate insulator are reported for the first time. Leakage current measurements show that the 11-nm-thick native oxide grown from an In0.49Al0.51P layer lattice-matched to GaAs has good insulating properties, with a measured leakage current density of 1.39×10-7 mA\\/?m2 at 1 V bias. GaAs MOSFETs with InAlP native gate

X. Li; Y. Cao; D. C. Hall; P. Fay; B. Han; A. Wibowo; N. Pan

2004-01-01

323

Novel WSi/Au T-shaped gate GaAs metal-semiconductor field-effect-transistor fabrication process for super low-noise microwave monolithic integrated circuit amplifiers  

SciTech Connect

A fully ion-implanted self-aligned T-shaped gate Ga As metal-semiconductor field-effect transistor (MESFET) with high frequency and extremely low-noise performance has been successfully fabricated for super low-noise microwave monolithic integrated circuit (MMIC) amplifiers. A subhalf-micrometer gate structure composed of WSi/Ti/Mo/Au is employed to reduce gate resistance effectively. This multilayer gate structure is formed by newly developed dummy SiON self-alignment technology and a photoresist planarization process. At an operating frequency of 12 GHz, a minimum noise figure of 0.87 dB with an associated gain of 10.62 dB has been obtained. Based on the novel FET process, a low-noise single-stage MMIC amplifier with an excellent low-noise figure of 1.2 dB with an associated gain of 8 dB in the 14 GHz band has been realized. This is the lowest noise figure ever reported at this frequency for low-noise MMICs based on ion-implanted self-aligned gate MESFET technology. 14 refs., 9 figs.

Takano, H.; Hosogi, K.; Kato, T. [Mitsubishi Electric Corp., Itami (Japan)] [and others

1995-05-01

324

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.

Hwang, Harold

2011-08-11

325

Bipolar disorder  

MedlinePLUS

Beynon S, Soares-Weiser K, Woolacott N, Duffy S, Geddes JR. Pharmacological interventions for the prevention of relapse in bipolar disorder: a systematic review of controlled trials. J Psychopharmacol . 2009; 23(5):574- ...

326

Bipolar Disorder  

MedlinePLUS

... is a mental illness that causes extreme mood swings. This condition is also called manic-depressive illness ... doctors will work together to control your mood swings and make sure you stay well. Bipolar disorder ...

327

High current transistor pulse generator  

NASA Astrophysics Data System (ADS)

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

Nesterov, V.; Cassel, R.

1991-05-01

328

Enhanced gallium arsenide metal-semiconductor field effect transistors designed for high temperature operation  

Microsoft Academic Search

An enhanced gallium arsenide (GaAs) metal-semiconductor field effect transistor (MESFET) has been developed which demonstrates the capability of operating at temperatures greater than 350°C. At elevated temperatures, the semi-insulating substrate of traditional GaAs MESFETs begins to conduct significant amounts of current. These leakage currents degrade device performance by introducing inter-device leakage paths (through pad and interconnect metal) and intra-device leakage

Rocky R. Reston; Hyong Y. Lee; Chris R. Ito; Gerald J. Trombley; Charles K. Havasy; B. Johnson

1994-01-01

329

High-frequency submicrometer Al/sub 0. 48/In/sub 0. 52/As/In/sub 0. 53/Ga/sub 0. 47/As heterostructure bipolar transistors  

SciTech Connect

The authors present the first successful high-speed scaling of a compound semiconductor HBT. Transistors with emitter dimensions of 0.5 x 11 and 3.5 x 3.5{mu}m/sup 2/ exhibit unity current gain cutoff frequencies of 63 and 70 GHz, respectively. Emitter current density greater than 3.3 x 10/sup 5/ A/cm/sup 2/ is demonstrated in a submicrometer AlInAs/InGaAs HBT.

Jalali, B.; Nottenburg, R.N.; Chen, Y.K.; Sivco, D.; Humphrey, D.A.; Cho, A.Y. (AT and T Bell Labs., Murray Hill, NJ (USA))

1989-08-01

330

Bipolar disorder.  

PubMed

Bipolar disorder's unique combination of three characteristics - clear genetic diathesis, distinctive clinical features, early availability of an effective treatment (lithium) - explains its special place in the history of psychiatry and its contribution to the current explosive growth of neuroscience. This article looks at the state of the art in bipolar disorder from the vantage point of: (i) genetics (possible linkages on chromosomes 18 and 21q, polygenic hypothesis, research into genetic markers); (ii) diagnosis (new focus on the subjective aspects of bipolar disorder to offset the current trend of underdiagnosis due to overreliance on standardized interviews and rating scales); (iii) outcome (increase in treatment-resistant forms signaling a change in the natural history of bipolar disorder); (iv) pathophysiology (research into circadian biological rhythms and the kindling hypothesis to explain recurrence); (v) treatment (emergence of the anticonvulsants, suggested role of chronic antidepressant treatment in the development of treatment resistance); (vi) neurobiology (evaluation of regulatory function in relation to affective disturbances, role of postsynaptic second-messenger mechanisms, advances in functional neuroimaging); and (vii) psychosocial research (shedding overly dualistic theories of the past to understand the mind and brain as an entity, thus emphasizing the importance of balancing the psychopharmacological and psychotherapeutic approaches). Future progress in the understanding and treatment of bipolar disorder will rely on successful integration of the biological and psychosocial lines of investigation. PMID:22033232

Goodwin, F K; Ghaemi, S N

1999-06-01

331

Design, performance, and application of a new bipolar synchronous rectifier  

NASA Astrophysics Data System (ADS)

A bipolar transistor which is specifically designed for synchronous rectifier applications is described with emphasis placed on its design and performance. It is shown that as opposed to conventional devices such as the Schottky, the proposed transistor has an emitter-base voltage exceeding 50 V, which in effect allows for first and third quadrant blocking. Moreover, this feature enables the transistor to be used in a pulse width modulation mode where both regulation and rectification can be achieved in the power supply secondary. A novel base drive circuit is employed which results in only a minor increase in complexity, but allows for operation at switching frequencies up to 250 kHz.

Hower, P. L.; Kepler, G. M.; Patel, R.

332

Surface passivation studies of aluminum gallium nitride\\/gallium nitride high electron mobility transistors  

Microsoft Academic Search

GaN based transistors have recently emerged as contenders for replacing existing Si and GaAs RF power devices. Wide bandgap group III-N materials exhibit the benefits of high electric field breakdown strength and high saturated carrier velocity, which allow for high power and high frequency device operation. While the theoretical advantages of the AlGaN\\/GaN high electron mobility transistor (HEMT) are beginning

David J. Meyer

2008-01-01

333

GaAs FET with a high mobility self-assembled planar nanowire channel on a (100) substrate  

Microsoft Academic Search

We demonstrate for the first time, a metal-semiconductor field-effect transistor (MESFET) fabricated with a selfassembled and high mobility GaAs planar nanowire (NW) channel. The planar NWs were grown on GaAs (100) substrates with metalorganic chemical vapor deposition (MOCVD) through gold (Au) catalyzed vapor-liquidsolid (VLS) mechanism. Unlike conventional out-of-plane NWs, these planar NWs grow selfaligned in the [0-11] or [01-1] directions

S. A. Fortuna; Xiuling Li

2009-01-01

334

Ga2O3(Gd2O3) as a dielectric insulator for GaAs device applications  

Microsoft Academic Search

The novel deposition technique of Ga2O3(Gd2O3) film by using in-situ molecular beam epitaxy (MBE) has led to the first demonstration of enhancement mode GaAs metal oxide semiconductor field effect transistors. For sub- micron GaAs device applications, the current leakage in the gate dielectric of reduced thickness has been an important issue. In this work, we address this aspect for the

Tsong S. Lay; Minghwei Hong; J. P. Mannaerts; C. T. Liu; Jueinai R. Kwo; Fan Ren; M. A. Marcus; K. K. Ng; Young-Kai Chen; Li-Jen Chou; Kuang-Chien Hsieh; K. Y. Cheng

1998-01-01

335

Stoichiometry-related defects in GaAs grown by molecular-beam epitaxy at low temperatures  

Microsoft Academic Search

GaAs layers grown by molecular-beam epitaxy (MBE) at very low substrate temperatures have gained considerable interest as buffer layers for GaAs metal--semiconductor field effect transistors (MESFET's) due to high resistivity and excellent device isolation. However, the structure and the electronic properties of such layers have not yet been investigated in detail. We have studied unannealed low temperature (LT) MBE layers

M. Kaminska; E. R. Weber; Z. Liliental-Weber; R. Leon; Z. U. Rek

1989-01-01

336

Progress on GaAs cryogenic readout circuits for SISCAM  

NASA Astrophysics Data System (ADS)

We are developing cryogenic readout circuits for the array of superconducting tunneling junctions (STJs) at submillimeter wavelength SISCAM (Superconductive Imaging Submillimeter-wave CAMera). A current conceptual design of SISCAM will employ a direct hybrid array system just like CMOS image sensors widely used at optical and infrared wavelength. Because of relatively large impedance of the STJ fabricated by RIKEN (~10 M? in a dark condition), it requires readout preamplifier with low current noise. Therefore, it is not suitable for the STJ to use a readout system by Superconductive Quantum Interferences Devices as for Transition Edge Sensor. Instead, we selected capacitive transimpedance amplifier (CTIA) using a SONY n-type GaAs Junction Field Effect Transistor (JFET). However, the CTIA has not been used as the readout of the STJ. Therefore, we measured the photocurrent of the STJ by the CTIA with Silicon JFETs and by transimpedance amplifier (TIA), which is a conventional readout for the STJ, in the same bias condition, and confirmed both results are in good agreement. Additionally, we report development of readout integrated circuits with GaAs JFETs. In order to design the CTIA circuit with the GaAs JFETs, we fabricated the independent GaAs JFETs and matched pairs of them. We measured electrical characteristics of these GaAs JFETs at the cryogenic temperatures less than 4.2 K. We demonstrated performance of an operational amplifier fabricated with the GaAs JFETs measuring a differential amplifier with the dual GaAs JFET, and additionally estimate amplifier gain, offset voltage, and power consumption of the CTIA by the circuit simulation using the PSPICE. In consequence, the expected performance fulfills the requirements for the readout amplifier of the STJs except for the noise performance.

Nagata, H.; Kobayashi, J.; Matsuo, H.; Fujiwara, M.

2006-07-01

337

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

338

Bipolar circuits for stabilization of power in variable resistors  

Microsoft Academic Search

The authors describe bipolar circuits designed to control and stabilize power dissipated in a variable load resistor. Three approaches are used. The circuits can be designed with two linear voltage-controlled current sources or with a controlled current source introduced in the translinear loop of four transistors or by using a translinear loop with two currents where the load power is

I. M. Filanovsky; C. A. Leme; V. A. Piskarev; H. Baltes

1992-01-01

339

Bipolar Microprocessor Circuits.  

National Technical Information Service (NTIS)

The development of bipolar microprocessor devices and the cross software (ASSEMBLER, SIMULATOR) for a bipolar microprocessor system is addressed. Two MSI peripheral devices and three bipolar microprocessor LSI devices (RALU, SEQUENCER, INTERRUPT UNIT) are...

G. Weil

1979-01-01

340

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 ... like an illness. What is the difference between bipolar disorder and ordinary mood swings? The three main things ...

341

Developments in Transistor Electronics†  

Microsoft Academic Search

The design theory of point-contact and junction transistors is reviewed in this paper. Selected examples illustrate the small-signal and large-signal properties of junction transistors. These phenomena are related to the theory of p— n junctions. Also, it is indicated how circuit engineers benefit from a certain know-ledge of transistor theory.

L. B. Valdes

1958-01-01

342

Bipolar electrochemistry.  

PubMed

A bipolar electrode (BPE) is an electrically conductive material that promotes electrochemical reactions at its extremities (poles) even in the absence of a direct ohmic contact. More specifically, when sufficient voltage is applied to an electrolyte solution in which a BPE is immersed, the potential difference between the BPE and the solution drives oxidation and reduction reactions. Because no direct electrical connection is required to activate redox reactions, large arrays of electrodes can be controlled with just a single DC power supply or even a battery. The wireless aspect of BPEs also makes it possible to electrosynthesize and screen novel materials for a wide variety of applications. Finally, bipolar electrochemistry enables mobile electrodes, dubbed microswimmers, that are able to move freely in solution. PMID:23843205

Fosdick, Stephen E; Knust, Kyle N; Scida, Karen; Crooks, Richard M

2013-07-10

343

Broadband cryogenic preamplifiers incorporating GaAs MESFETs for use with low-temperature particle detectors  

SciTech Connect

Two voltage-sensitive preamplifier designs are presented for operation at 1.6 K. Both designs incorporate GaAs MESFETs (Plessy P35-1101). The first design has two stages including a common-source gain stage and a source follower stage. The noise performance, particularly with the low-frequency noise, was found to improve with cooling. The white-noise level at low temperature is 1 nV/Hz{sup 1/2}, and the low-frequency noise corner occurs at approximately 1 MHz. The voltage gain into 50 {Omega} is 7.0 dB, with the {minus}3-dB point occuring at 10 MHz. The noise of the first stage was found to dominate the total noise at the output of a low-noise room-temperature post amplifier. The output impedance of the preamplifier is 50 {Omega}. The second design incorporates one cold FET, dissipating 1 mW, in cascode with a room-temperature bipolar transistor. The noise of this design was found to be approximately equal to that of the two-cold-stage design except for a bulge in the voltage noise centered at 13 MHz due to impedance mismatching of the line to room temperature. The gain of this design is 21 dB, with the {minus}3-dB point at 2 MHz. Cryogenic semiconductor operation is discussed, design parameters of the two preamplifiers are discussed in detail, noise measurements are presented along with a discussion of the different temperature- and bias-dependent noise sources, and an analysis of the signal-to-noise ratio and rise time for the present detection scheme is made.

Lee, A.T. (Physics Department, Stanford University, Stanford, California 94305 (US))

1989-10-01

344

Failure mode analysis of AlGaAs GaAs HBTs using electrostatic discharge method  

Microsoft Academic Search

The failure modes of AlGaAsGaAs heterojunction bipolar transistors (HBTs) showing increases of base leakage current found during the bias and temperature reliability test have been examined and analysed by using an electrostatic discharge (ESD) method. In the examination for HBT having an emitter of 2 × 20 ?m, increases of a base leakage current have been observed when an ESD

Yorito Ota; Manabu Yanagihara; Morio Nakamura

1995-01-01

345

Screening for Bipolar Disorder  

Microsoft Academic Search

Bipolar disorder is a recurrent and some- times chronic illness involving episodes of depression and mania or hypomania. The most frequent presentation is depression: more than 1 of 5 primary care patients with depression have bipolar disorder. The symptoms of bipolar depres- sion often differ from those of unipolar depression. Age of onset for bipolar disorder is usually the late

A. L. Brickman

2002-01-01

346

Hot-carrier reliability and design of N-LDMOS transistor arrays  

Microsoft Academic Search

The increase in handheld and portable appliances operating in the 20-30 V range have driven the need for IC power management control devices. These circuits combine high performance CMOS and bipolar transistors with a power MOS driver. The n-channel lateral DMOS (N-LDMOS) is a common choice for the driver transistor. Because of high drain voltages used by LDMOS devices hot-carrier

Douglas Brisbin; Andy Strachan; Prasad Chaparala

2001-01-01

347

Properties of TiO2 Thin Films and a Study of the TiO2-Gaas Interface.  

National Technical Information Service (NTIS)

Titanium dioxide (TiO2) films prepared by chemical vapor deposition were investigated in this study for the purpose of the application in the GaAs metal-insulator-semiconductor field-effect transistor. The degree of crystallization increases with the depo...

C. Y. Chen M. A. Littlejohn

1977-01-01

348

The impact of low temperature materials on the breakdown and noise properties of GaAs and InP based HEMT's and FET's  

Microsoft Academic Search

The breakdown voltage in GaAs field effect transistors (FET) has been the fundamental limitation of power performance in these devices. Previous studies have identified the high electric field at the drain edge of the gate metal as the cause of breakdown. At the start of this project, we successfully demonstrated that a low-temperature-grown GaAs (LTG-GaAs) surface 'insulator' dramatically improved the

Umesh K. Mishra

1994-01-01

349

The MOS controlled super junction transistor (SJBT): a new, highly efficient, high power semiconductor device for medium to high voltage applications  

Microsoft Academic Search

The paper presents a new MOS controlled silicon power device with columnar super junction structures. The super junction bipolar transistor (SJBT) is an extension of the super junction MOSFET principle: due to it's p-emitter at the anode the device is bipolar in nature albeit with substantially different characteristics as compared to an IGBT. It's electrical performance rivals advanced trench IGBTs.

F. Bauer

2002-01-01

350

Simultaneous single event charge sharing and parasitic bipolar conduction in a highly-scaled SRAM design  

Microsoft Academic Search

A novel mechanism for upset is seen in a commercially available 0.25 ?m 10-T SEE hardened SRAM cell. Unlike traditional multiple node charge collection in which diffusions near a single event strike collect the deposited carriers, this new mechanism involves direct drift-diffusion collection at an NFET transistor in conjunction with parasitic bipolar conduction in nearby PFET transistors. The charge collection

Brian D. Olson; Dennis R. Ball; Kevin M. Warren; Lloyd W. Massengill; Nadim F. Haddad; Scott E. Doyle; Dale McMorrow

2005-01-01

351

Comparison of pnp and npn InGaAlAs/InGaAs heterojunction bipolar  

SciTech Connect

The molecular-beam epitaxial growth conditions and characteristics of npn and pnp heterojunction bipolar transistors in the InGaAlAs/InGaAs material system are described. Direct-current current gains of more than 15 000 have been obtained for npn heterojunction bipolar transistors (HBTs). pnp HBTs have a larger breakdown voltage compared to equivalent npn HBTs. A novel pnp HBT structure in which a strained hole filter is placed just above the base to inject light holes preferentially is proposed. The high speed performance of pnp HBTs is at present limited by emitter series resistance. 12 refs., 3 figs.

Dodabalapur, A.; Chang, T.Y. [AT & T Bell Laboratories, Holmdel, NJ (United States)

1993-05-01

352

Integration of front-end electronics with GaAs pixel detectors: Experimental and feasibility analysis  

SciTech Connect

This work aims to study the feasibility of the integration, on the same chip, of GaAs pixel detectors and frontend electronics employing GaAs metal semiconductor FET`s (MESFET`s) or high electron mobility transistors (HEMT`s). The interest of fully integrated GaAs systems lies in X and {gamma}-ray spectroscopy and Imaging for scientific, industrial, and medical applications. The system design criteria and the prediction of the performance have been derived on the basis of recent experimental results on semi-insulating GaAs pixel detectors. Measurements of the relevant parameters of GaAs FET`s suitable for the stringent requirements of a specroscopy-grade frontend amplifier are analyzed. It is shown that an optimized GaAs integrated system can reach an electronic noise level below 100 electrons rms (<1 keV FWHM) even at room temperature. Some open problems regarding the detector-electronics integration are highlighted and discussed.

Bertuccio, G.; Longoni, A.; De Geronimo, G. [Politecnico di Milano (Italy); Canali, C. [Dipt. di Scienze dell`Ingegeneria and INFM, Modena (Italy); Lanzieri, C. [Alenia, Roma (Italy); Nava, F. [Dipt. di Fisica and INFN Bologna, Modena (Italy)

1999-08-01

353

Diagnostic issues in bipolar disorder  

Microsoft Academic Search

Bipolar disorder is a highly recurrent and chronic psychiatric condition that shortens life expectancy, causes functional impairment and disruption to social, work and family life. Several forms of bipolar disorder are recognised, including both bipolar I and bipolar II disorder. Bipolar I is characterised by recurrent episodes of depression and mania whereas bipolar II disorder is characterised by recurrent depression

Jules Angst; Alex Gamma; Franco Benazzi; Vladeta Ajdacic; Dominique Eich; Wulf Rössler

2003-01-01

354

Quantum interference in transistors  

Microsoft Academic Search

We consider adiabatic charge transport through transistor based on quantum dot caused by two periodically changing external perturbations. Both the magnitude and the sign of the transmitted charge are extremely sensitive to the configuration of the transistor and to the magnetic field. We find the correlation function characterizing the random value of this pumped charge for arbitrary strength of perturbation.

Timur A. Shutenko; Igor L. Aleiner; Boris L. Altshuler

2008-01-01

355

TRANSISTORIZED RADIATION MONITORS  

Microsoft Academic Search

Paper presented at I.R.E. Professional Group on Nuclear Science ; Meeting, New York, Oct. 3l, l957. The advantages of transistors over vacuum ; tubes in radiation instruments have long been realized but a somewhat different ; approach to circuit design must be followed in developing transistor instruments, ; as compared with that used in vacuum tube circuits, and this seems

Goulding

1957-01-01

356

Transistorized Radiation Monitors  

Microsoft Academic Search

The advantages of transistors over vacuum tubes in radiation instruments have long been realized but a somewhat different approach to circuit design must be followed in developing transistor instruments, as compared with that used in vacuum tube circuits, and this seems to have discouraged many from developing such circuits. The purpose of this paper is to describe in some detail

F. S. Goulding

1958-01-01

357

Infrared light emission from GaAs MESFETs operating at avalanche breakdown conditions  

Microsoft Academic Search

Visible and infrared light emission bands arising from avalanche breakdown between gate and drain contacts of high-frequency high-power GaAs field effect transistors have been studied. The decay time of the mid-infrared (mid-IR) light (photon energies in the range 0.25–0.5 eV) is considerably less than 25 ms, while light with photon energies below 0.25 eV decays in a few seconds after

K S Zhuravlev; V A Kolosanov; A G Milekhin; V G Polovinkin; T S Shamirzaev; Yu N Rakov; Yu B Myakishev; J Fryar; E McGlynn; M O Henry

2004-01-01

358

SPDT switch MMIC using E\\/D-mode GaAs JFETs for personal communications  

Microsoft Academic Search

The design and performance of a monolithic GaAs SPDT switch applicable to a time division duplexer for personal communications are described. For a switch IC used in a portable handset for personal communications, 3-V battery operation is mandatory. In order to meet this requirement, the IC was realized by utilizing four depletion-mode switch JFETs (junction field effect transistors) with superior

S. Kusunoki; T. Ohgihara; M. Wada; Y. Murakami

1992-01-01

359

Resistivity of dilute 2D electrons in GaAs in the metal-insulator regime  

Microsoft Academic Search

We report resistivity measurements as a function of temperature in a dilute 2D electron system (2DES). The 2DES is in an undoped GaAs heterostructure processed in an field-effect transistor geometry. With this technique, high mobilities are observed over a wide range of densities (0.16 to 8.0 × 10^10 cm-2). For high densities, the temperature dependence of the resistivity is quantitatively

M. P. Lilly; J. L. Reno; J. A. Simmons; I. B. Spielman; J. P. Eisenstein; L. N. Pfeiffer; K. W. West; E. H. Hwang; S. Das Sarma

2003-01-01

360

Compact dc model of GaAs FET's for large-signal computer calculation  

Microsoft Academic Search

A modified, simple and fairly accurate explicit expression of dc current-voltage characteristics of GaAs FET's is presented. A departure from the square-law behavior in saturation of the short channel transistor is induced by introducing drain-source voltage bias dependent pinch-off potential. The model proposed here needs four parameters extracted by the global curve-fitting technique of a measured family of drain current-voltage

T. Kacprzak; A. Materka

1983-01-01

361

Multi-scale thermal analysis of GaAs RF device  

Microsoft Academic Search

A multi-scale modeling approach is proposed and employed to investigate thermal issues in GaAs MMIC. Thermal analysis down to the signal transistor level was made possible with the development of this approach using the finite element technique. The multi-scale modeling results are then verified with an infrared temperature measurement technique (infrared micro-thermal imaging technique). Both modeling and experiment results have

Li Li; Roberto Coccioli; Kevin Nary; Phil Canfield

2005-01-01

362

VCSELs bonded directly to foundry fabricated GaAs smart pixel arrays  

Microsoft Academic Search

This letter reports the flip-chip bonding of an 8×8 array of free standing VCSELs to a foundry fabricated GaAs metal-semiconductor field-effect transistor (MESFET) smart pixel array. The VCSELs have oxide defined apertures and are co-planar bonded directly to smart pixels which perform the selection function of a data filter. The Vth and series resistance of the VCSELs were on average

Rui Pu; E. M. Hayes; R. Jurrat; C. W. Wilmsen; K. D. Choquette; H. Q. Hou; K. M. Geib

1997-01-01

363

Deep submicrometer super self-aligned Si bipolar technology with 25.4 ps ECL  

Microsoft Academic Search

A new deep submicron double-poly self-aligned Si bipolar technology has been developed using a 0.3-?m design rule, a collector polysilicon trench electrode, and oxide-filled trench isolation. This technology is called “High-Performance Super Self-Aligned Process Technology” or HSST. 0.3-?m minimum patterning is achieved by electron-beam direct writing technology. The HSST bipolar transistor is 2.5 times smaller than the previous 1-?m SST-1B.

Shinsuke Konaka; Mamoru Ugajin; Tadahito Matsuda

1994-01-01

364

SiGe bipolar ICs for 20 Gb\\/s optical transmitter  

Microsoft Academic Search

SiGe bipolar ICs, a selector, a multiplier and a D-type flip-flop, have been developed for a 20 Gb\\/s optical transmitter by using a self-aligned SiGe base bipolar transistor with bonded SOI technology. In the selector IC and the multiplier IC, an internal high speed clock buffer circuit accomplishes stable operation under a single clock input condition

T. Hashimoto; H. Tezuka; F. Sato; M. Soda; T. Suzaki; T. Tatsumi; T. Tashiro

1994-01-01

365

Single transistor latch phenomenon in junctionless transistors  

NASA Astrophysics Data System (ADS)

In this work, we report on the single transistor latch phenomenon in junctionless transistors. In the latch condition, the device is unable to turn-off despite a reduction in gate bias. It is shown that impact ionization induced latch condition can occur due to an increase in drain bias, silicon film thickness, gate oxide thickness, and doping concentration. The latch phenomenon is explained in terms of generation-recombination rates, electrostatic potential, electric field distribution and product of current density and electric field (J.E). As latch condition is undesirable for dynamic memory applications, the work highlights the significance of (J.E) as a performance metric to avoid the junctionless transistor being driven into the latch mode.

Singh Parihar, Mukta; Ghosh, Dipankar; Kranti, Abhinav

2013-05-01

366

Network Analysis Approach to Multidimensional Modeling of Transistors Including Thermal Effects  

Microsoft Academic Search

A comprehensive numerical model for simulating the electrical and thermal behavior of a bipolar transistor is developed. The proposed model is in the form of an electrical network for its easy implementation using a circuit analysis program. One of the suggested solution techniques enables us to simulate a fairly large problem with a reasonable amount of computer time. The effect

M. Latif; P. R. Bryant

1982-01-01

367

Bipolar disorder: diagnostic issues  

Microsoft Academic Search

Bipolar disorders are cyclical mood disorders with clinical features including distinct sustained periods of mood elevation. • Briefer (4 days or more), mild episodes of mood elevation define bipolar II disorder; lengthier (7 days or more), more severe episodes (or those requiring hospitalisation), with or without psychotic features, define bipolar I disorder. • Depressive periods are more common and lengthier

John W G Tiller; Isaac Schweitzer

2010-01-01

368

Gain Limitations of a Single-Transistor Voltage Amplifier  

NASA Astrophysics Data System (ADS)

The maximum voltage gain achievable with an amplifier, using only a single bipolar transistor, is shown to depend mainly on the power supply voltage Vcc. Textbooks show that the gain of an emitter follower amplifier is the product of the trans-conductance and the collector resistor, making it seem as though one can increase the gain indefinitely by choosing better transistors and/or larger resistors. However, to prevent saturation (and decreased gain) these parameters are not independent. Thus, the maximum possible gain Gmax is nearly independent of the transistor characteristics. For small signal one-transistor AC amplifiers, Gmax is found to be Gmax = Vcc/(nkT/q) = Vcc/(0.026 n Volts) at room temperature. Here n is the ideality factor of the base-emitter junction, a number that is typically between 1 and 2. For large signal AC amplifiers Gmax is reduced by a factor of two. Emitter stabilization reduces the maximum gain (in our example by a factor of ten) but extends the gain to DC, and makes it independent of temperature. It also allows for "universal" replacement transistors, requiring only a sufficiently high voltage rating, and a nearly linear current gain large compared to unity.

Penchina, Claude M.

2001-03-01

369

Spin Hall Effect Transistor  

NASA Astrophysics Data System (ADS)

The field of semiconductor spintronics explores spin-related quantum relativistic phenomena in solid-state systems. Spin transistors and spin Hall effects have been two separate leading directions of research in this field. We have combined the two directions by realizing an all-semiconductor spin Hall effect transistor. The device uses diffusive transport and operates without electrical current in the active part of the transistor. We demonstrate a spin AND logic function in a semiconductor channel with two gates. Our study shows the utility of the spin Hall effect in a microelectronic device geometry, realizes the spin transistor with electrical detection directly along the gated semiconductor channel, and provides an experimental tool for exploring spin Hall and spin precession phenomena in an electrically tunable semiconductor layer.

Wunderlich, Jörg; Park, Byong-Guk; Irvine, Andrew C.; Zârbo, Liviu P.; Rozkotová, Eva; Nemec, Petr; Novák, Vít; Sinova, Jairo; Jungwirth, Tomás

2010-12-01

370

Spin Hall effect transistor.  

PubMed

The field of semiconductor spintronics explores spin-related quantum relativistic phenomena in solid-state systems. Spin transistors and spin Hall effects have been two separate leading directions of research in this field. We have combined the two directions by realizing an all-semiconductor spin Hall effect transistor. The device uses diffusive transport and operates without electrical current in the active part of the transistor. We demonstrate a spin AND logic function in a semiconductor channel with two gates. Our study shows the utility of the spin Hall effect in a microelectronic device geometry, realizes the spin transistor with electrical detection directly along the gated semiconductor channel, and provides an experimental tool for exploring spin Hall and spin precession phenomena in an electrically tunable semiconductor layer. PMID:21205664

Wunderlich, Jörg; Park, Byong-Guk; Irvine, Andrew C; Zârbo, Liviu P; Rozkotová, Eva; Nemec, Petr; Novák, Vít; Sinova, Jairo; Jungwirth, Tomás

2010-12-24

371

Graphene Nanoribbon Tunnel Transistors  

Microsoft Academic Search

A graphene nanoribbon (GNR) tunnel field-effect transistor (TFET) is proposed and modeled analytically. Ribbon widths between 3 and 10 nm are considered to effect energy bandgaps in the range of 0.46 to 0.14 eV. It is shown that a 5-nm ribbon width TFET can switch from on to off with only 0.1-V gate swing. The transistor achieves 800 muA\\/mum on

Qin Zhang; Tian Fang; Huili Xing; Alan Seabaugh; Debdeep Jena

2008-01-01

372

Spin Hall Effect Transistor  

Microsoft Academic Search

The field of semiconductor spintronics explores spin-related quantum relativistic phenomena in solid-state systems. Spin transistors and spin Hall effects have been two separate leading directions of research in this field. We have combined the two directions by realizing an all-semiconductor spin Hall effect transistor. The device uses diffusive transport and operates without electrical current in the active part of the

Jörg Wunderlich; Byong-Guk Park; Andrew C. Irvine; Liviu P. Zârbo; Eva Rozkotová; Petr Nemec; Vít Novák; Jairo Sinova; Tomás Jungwirth

2010-01-01

373

Biomolecular detection using a metal semiconductor field effect transistor  

NASA Astrophysics Data System (ADS)

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

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

2010-04-01

374

Hardness assurance for long-term ionizing radiation effects on bipolar structures  

Microsoft Academic Search

This work assessed the theoretical understanding of long-term ionization effects in semiconductor bipolar devices in support of developing hardness assurance techniques. The principal effort was directed at investigating transistor gain degradation mechanisms by use of models relating semiconductor physical and electrical parameters to surface properties. Ionizing radiation effects on surface properties were used to identify critical physical parameters for use

A. R. Hart; J. B. Smyth Jr.; J. P. Raymond; V. A. J. Vanlint

1978-01-01

375

A bipolar device modeling technique applicable to computer-aided circuit analysis and design  

Microsoft Academic Search

The development of a modeling technique for bipolar devices is described. The application of the technique results in complete and realistic large-signal models which are amenable to computer-aided analysis. SCEPTRE has been used to effectively analyze derived models, and results of SCEPTRE analyses of a developed transistor model are presented to illustrate the general capabilities of the modeling technique and

J. G. Fossum

1973-01-01

376

A compact bipolar class-HB output stage using 1-V power supply  

Microsoft Academic Search

A compact circuit topology for the realization of a bipolar class-HB output stage operating down to 0.9 V is presented. This compact topology is obtained by using the same path for the signal as well as for the definition of the bias current in the output transistors. The output amplifier is used to drive a 64-? load, representing the series

Frank J. M. Thus

1992-01-01

377

Modeling MOS snapback and parasitic bipolar action for circuit-level ESD and high current simulations  

Microsoft Academic Search

A circuit-level simulator for ESD and EOS is presented. Equations for modeling the high current behavior of NMOS and PMOS transistors have been developed and implemented in SPICE. A simple and practical extraction methodology for obtaining the bipolar parameters is given, which uses the three terminal currents obtained from a single high current I-V curve. Simulation results are presented and

Ajith Amerasekera; Srini Ramaswamy; Mi-Chang Chang; Charvaka Duvvury

1996-01-01

378

New GaAs FETs.  

National Technical Information Service (NTIS)

The widespread employment of satellite communications has been accompanied by expanded applications for microwave-communications equipment. As GaAs FETs figure prominently in efforts to extend the lifetimes and reduce the sizes of microwave-communications...

M. Yamanouchi T. Sonoda

1990-01-01

379

First demonstration of a planar-type surface tunnel transistor (STT): Lateral interband tunnel device  

Microsoft Academic Search

Planar-type surface tunnel transistors (STTs), that are adequate for device miniaturization and high-level integration, are demonstrated for the first time. Two planar-type STTs based on GaAs and In0.2Ga0.8As systems were fabricated using MBE regrowth techniques. Both devices exhibited clear gate-controlled negative differential resistance (NDR) characteristics due to interband tunneling, and their basic operation was confirmed. The maximum peak current density

T. Uemura; T Baba

1996-01-01

380

Monte Carlo simulations of hot-electron spectroscopy in planar-doped barrier transistors  

Microsoft Academic Search

A microscopic model is developed to study the hot electron-spectroscopy method which uses GaAs planar-doped barrier transistors. This simulation is based on the Monte Carlo method, and includes the effects of ionized impurity scattering, pair electron-electron scattering, long-range plasmon scattering, and coupled plasmon\\/phonon scattering. The nonparabolicity of the band structure and the Pauli exclusion principle are also taken into account

T. Wang; K. Hess; G. J. Iafrate

1986-01-01

381

A 6-bit, 4 GSa\\/s ADC fabricated in a GaAs HBT process  

Microsoft Academic Search

A GaAs-AlGaAs Heterojunction Bipolar Transistor (HBT) process was developed to meet the speed, gain and yield requirements for Analog to Digital Converters (ADCs). A 6-bit, 4 GSa\\/s (4 giga-samples per second) ADC was designed and fabricated in this process. The standard HBT used has an emitter area of 1.4×3.0 ?m; it has current gain of over 70 at Ic=1 mA

Ken Poulton; Knud L. Knudsen; John J. Corcoran; Keh-Chung Wang; Randy B. Nubling; Richard L. Pierson; Mau-Chung F. Chang; Peter M. Asbeck; R. T. Huang

1994-01-01

382

The resonant body transistor.  

PubMed

This paper introduces the resonant body transistor (RBT), a silicon-based dielectrically transduced nanoelectromechanical (NEM) resonator embedding a sense transistor directly into the resonator body. Combining the benefits of FET sensing with the frequency scaling capabilities and high quality factors (Q) of internal dielectrically transduced bar resonators, the resonant body transistor achieves >10 GHz frequencies and can be integrated into a standard CMOS process for on-chip clock generation, high-Q microwave circuits, fundamental quantum-state preparation and observation, and high-sensitivity measurements. An 11.7 GHz bulk-mode RBT is demonstrated with a quality factor Q of 1830, marking the highest frequency acoustic resonance measured to date on a silicon wafer. PMID:20180594

Weinstein, Dana; Bhave, Sunil A

2010-04-14

383

Mechanisms for radiation dose-rate sensitivity of bipolar transistors.  

SciTech Connect

Mechanisms for enhanced low-dose-rate sensitivity are described. In these mechanisms, bimolecular reactions dominate the kinetics at high dose rates thereby causing a sub-linear dependence on total dose, and this leads to a dose-rate dependence. These bimolecular mechanisms include electron-hole recombination, hydrogen recapture at hydrogen source sites, and hydrogen dimerization to form hydrogen molecules. The essence of each of these mechanisms is the dominance of the bimolecular reactions over the radiolysis reaction at high dose rates. However, at low dose rates, the radiolysis reaction dominates leading to a maximum effect of the radiation.

Witczak, Steven Christopher; Hembree, Charles Edward; Pease, Ronald L. (RL Research, Albuquerque, NM); Hjalmarson, Harold Paul; Shaneyfelt, Marty Ray; Mattsson, Thomas Kjell Rene; Edwards, Arthur H. (Air Force Research Labs, Albuquerque, NM); Schwank, James Ralph

2003-07-01

384

IGBT (Insulated Gate Bipolar Transistors) Inverter for AC Motor Drive,  

National Technical Information Service (NTIS)

General-purpose inverters and servo drivers are used for many types of devices, including FA equipment, and the fields of application have been expanding significantly. On the other hand, reducing the motor acoustic noise is one of the major concerns in s...

T. Ambo Y. Eimoto

1988-01-01

385

Electronic conduction in a model three-terminal molecular transistor.  

PubMed

The electronic conduction of a novel, three-terminal molecular architecture, analogous to a heterojunction bipolar transistor, is studied. In this architecture, two diode arms consisting of donor-acceptor molecular wires fuse through a ring, while a gate modulating wire is a pi-conjugated wire. The calculated results show the enhancement or depletion mode of a transistor on applying a gate field along the positive or negative direction. A small gate field is required to switch on the current in the proposed architecture. The changes in the electronic conduction can be attributed to the intrinsic dipolar molecular architecture in terms of the evolution of molecular wavefunctions, specifically the one associated with the terphenyl group of the modulating wire in the presence of the gate field. PMID:19942764

He, Haiying; Pandey, Ravindra; Karna, Shashi P

2008-11-24

386

Electronic conduction in a model three-terminal molecular transistor  

NASA Astrophysics Data System (ADS)

The electronic conduction of a novel, three-terminal molecular architecture, analogous to a heterojunction bipolar transistor, is studied. In this architecture, two diode arms consisting of donor-acceptor molecular wires fuse through a ring, while a gate modulating wire is a ?-conjugated wire. The calculated results show the enhancement or depletion mode of a transistor on applying a gate field along the positive or negative direction. A small gate field is required to switch on the current in the proposed architecture. The changes in the electronic conduction can be attributed to the intrinsic dipolar molecular architecture in terms of the evolution of molecular wavefunctions, specifically the one associated with the terphenyl group of the modulating wire in the presence of the gate field.

He, Haiying; Pandey, Ravindra; Karna, Shashi P.

2008-12-01

387

Structures for high frequency transistor  

NASA Astrophysics Data System (ADS)

Submicron vertical electron flow structures were grown by Molecular Beam Epitaxy (MBE) with and without ballistic electron launchers. Both electron flow down toward the substrate and up away from the substrate were studied. Angle evaporation of metal, on the sides of etched vertical channels, was used to form Schottky gates. The placement of the gates at the launch plane for ballistic electrons was found to be critical. Ohmic contacts with improved performance and stability on n-type GaAs were studied using poly-Si on GaAs, Co on GaAs, and epitaxial Ge on GaAs.

Eastman, L. F.; Wendt, J.; Mayer, J. W.; Kavanaugh, K.

1989-02-01

388

Costs of Bipolar Disorder  

Microsoft Academic Search

Bipolar disorder is a chronic affective disorder that causes significant economic burden to patients, families and society. It has a lifetime prevalence of approximately 1.3%. Bipolar disorder is characterised by recurrent mania or hypomania and depressive episodes that cause impairments in functioning and health-related quality of life. Patients require acute and maintenance therapy delivered via inpatient and outpatient treatment. Patients

Leah S. Kleinman; Ana Lowin; Gian Gandhi; Eric Edgell; Dennis A. Revicki

2003-01-01

389

Management of Bipolar Depression  

PubMed Central

Patients with bipolar disorder spend more time in a depressed than manic state, even with individualized treatment. To date, bipolar depression is often misdiagnosed and ineffectively managed both for acute episodes and residual symptoms. This review attempts to summarize the current status of available treatment strategies in the treatment of bipolar depression. For acute and prophylactic treatment, a substantial body of evidence supports the antidepressive efficacy of lithium for bipolar disorders and its antisuicidal effects. Among numerous anticonvulsants with mood-stabilizing properties, valproate and lamotrigine could be first-line options for bipolar depression. Due to receptor profile, mood-stabilizing properties of second-generation antipsychotics have been explored, and up to date, quetiapine and olanzapine appear to be a reasonable option for bipolar depression. The usefulness of antidepressants in bipolar depression is still controversial. Current guidelines generally recommend the cautious antidepressant use in combination with mood stabilizers to reduce the risk of mood elevation or cycle acceleration. Results from clinical trials on psychosocial intervention are promising, especially when integrated with pharmacotherapy. Most patients with bipolar depression need individualized and combined treatment, although the published evidence on this type of treatment strategy is limited. Future studies on the utility of currently available agents and modalities including psychosocial intervention are required.

Chang, Jae Seung; Ha, Kyooseob

2011-01-01

390

Resonant tunneling transistor with quantum well base and high-energy injection - A new negative differential resistance device  

Microsoft Academic Search

A new negative conductance device consisting of a heterojunction bipolar transistor with a quantum well and a symmetric double barrier or a superlattice in the base region is proposed. The key difference compared to previously studied structures is that resonant tunneling is achieved by high-energy minority carrier injection into the quantum state rather than by application of an electric field.

Federico Capasso; R. A. Kiehl

1985-01-01

391

Accelerating the life of transistors  

NASA Astrophysics Data System (ADS)

Choosing small and medium power switching transistors of the NPN type in a 3DK set as the study object, the test of accelerating life is conducted in constant temperature and humidity, and then the data are statistically analyzed with software developed by ourselves. According to degradations of such sensitive parameters as the reverse leakage current of transistors, the lifetime order of transistors is about more than 104 at 100 °C and 100% relative humidity (RH) conditions. By corrosion fracture of transistor outer leads and other failure modes, with the failure truncated testing, the average lifetime rank of transistors in different distributions is extrapolated about 103. Failure mechanism analyses of degradation of electrical parameters, outer lead fracture and other reasons that affect transistor lifetime are conducted. The findings show that the impact of external stress of outer leads on transistor reliability is more serious than that of parameter degradation.

Haochun, Qi; Changzhi, Lü; Xiaoling, Zhang; Xuesong, Xie

2013-06-01

392

Comparison of GaAs JFETs to MESFETs for high-temperature operation  

SciTech Connect

GaAs-based Metal Semiconductor Field Effect transistors (MESFETs) and High Electron Mobility Transistors (HEMTs) have been the focus of research for high-temperature operation due to the 1.42 eV band gap of GaAs that reduces thermal carrier generation as compared to 1.1 eV silicon-based electronics. Although schemes have been proposed to minimize substrate currents at elevated temperatures, high-temperature operation of these devices is ultimately limited by the gate leakage current of the Schottky gate contact. Since a Junction Field Effect Transistor (JFET) has a higher gate barrier to current flow than a Schottky barrier MESFET as a result of the p/n junction gate, JFETs should have superior performance at elevated temperatures. This paper compares the high-temperature performance of a self-aligned GaAs MESFET and JFET. Both devices suffer from substrate leakage at high temperature; however, the JFET has superior gate characteristics and maintains a larger fraction of its room temperature transconductance at 300 C.

Zolper, J.C.; Hietala, V.M.; Housel, M.S.; Baca, A.G. [Sandia National Labs., Albuquerque, NM (United States); Sherwin, M.E. [Microwave Signal, Inc., Clarksburg, MD (United States)

1996-06-01

393

45nm Transistor Reliability  

Microsoft Academic Search

It has been clear for a number of years that increasing transistor gate leakage with device scaling would ultimately necessitate an alternative to traditional SiON dielectrics with polysilicon gates. Material systems providing higher dielectric constants, and therefore allowing physically thicker dielectrics, have been the object of extensive research. Such high-k dielectrics, when combined with metal gate electrodes, have emerged as

Jeffrey Hicks

394

Transistorized Digital Potentiometer.  

National Technical Information Service (NTIS)

An automatic transistorized digital potentiometer used for input to a digital computer is described. The potentiometer is used in a copper smelting plant to control slow time-varying processes and consists of three basic circuit blocks: a null, a divider,...

K. A. Netrebenko V. B. Reutov

1968-01-01

395

Photoresponsive nanoscale columnar transistors  

PubMed Central

This study reports a general methodology for making stable high-performance photosensitive field effect transistors (FET) from self-assembled columns of polycyclic aromatic hydrocarbons by using single-walled carbon nanotubes (SWNTs) as point contacts. In particular, the molecules used in this work are liquid crystalline materials of tetra(dodecyloxy)hexabenzocoronenes (HBCs) that are able to self-organize into columnar nanostructures with a diameter similar to that of SWNTs and then form nanoscale columnar transistors. To rule out potential artifacts, 2 different structural approaches were used to construct devices. One approach is to coat thin films of HBCs onto the devices with the SWNT–metal junctions protected by hydrogensilsesquioxane resin (HSQ), and the other is to place a droplet of HBC exactly on the nanogaps of SWNT electrodes. Both types of devices showed typical FET behaviors, indicating that SWNT–molecule–SWNT nanojunctions are responsible for the electrical characteristics of the devices. After thermally annealing the devices, HBC molecules assembled into columnar structures and formed more efficacious transistors with increased current modulation and higher gate efficiency. More interestingly, when the devices were exposed to visible light, photocurrents with an on/off ratio of >3 orders of magnitude were observed. This study demonstrates that stimuli-responsive nanoscale transistors have the potential applications in ultrasensitive devices for environmental sensing and solar energy harvesting.

Guo, Xuefeng; Xiao, Shengxiong; Myers, Matthew; Miao, Qian; Steigerwald, Michael L.; Nuckolls, Colin

2009-01-01

396

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

NASA Astrophysics Data System (ADS)

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

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

2008-05-01

397

Bipolar Disorder and Substance Abuse  

Microsoft Academic Search

Objectives: To review evidence about mechanisms and consequences of relationships between bipolar and substance use disorders.Methods: Articles were identified using a MEDLINE search linking (1) bipolar disorder to substance use disorders, alcoholism, and specific drugs, (2) bipolar disorder and substance abuse to treatment strategies, and (3) bipolar disorder or substance abuse to behavioral sensitization, impulsivity, and suicide. We attempted to

Alan C. Swann

2005-01-01

398

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

399

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

400

Misdiagnosis of Bipolar Disorder  

PubMed Central

The objective of this article is to review the literature on one of the most complex topics in contemporary psychiatry—the diagnosis of bipolar disorder. Bipolar disorder is a disabling psychiatric illness that is often misdiagnosed, especially on initial presentation. Misdiagnosis results in ineffective treatment, which further worsens the outcome. Major contributors toward misdiagnosis include lapses in history-taking, presence of psychiatric and medical comorbidities, and limitations in diagnostic criteria. Careful screening for symptoms of hypomania/mania and clinical features suggestive of bipolarity as well as use of collateral history and screening instruments, such as mood questionnaires, might help in limiting the rate of misdiagnosis.

Rajput, Muhammad

2006-01-01

401

Extracting transport parameters in GaAs nanopillars grown by selective-area epitaxy  

NASA Astrophysics Data System (ADS)

We investigate the transport properties in p-type GaAs nanopillars (NPs) grown on GaAs(111) B substrates using selective-area epitaxy by studying single-NP field-effect transistors. Experimental results indicate that normalized resistance and field-effect mobility are highly sensitive to NP dimensions. Both in situ and ex situ chemical surface passivation techniques are found to significantly improve conductivity and mobility, especially for the smaller diameter NPs. A semi-empirical model based on diameter dependent mobility is used to extract actual doping levels and surface state density by fitting normalized resistance as a function of NP diameter. Surface state densities before and after passivation are found to be 5 × 1012 cm-2 eV-1 and 7 × 1010 cm-2 eV-1, respectively.

Lin, Andrew; Shapiro, Joshua N.; Senanayake, Pradeep N.; Scofield, Adam C.; Wong, Ping-Show; Liang, Baolai; Huffaker, Diana L.

2012-03-01

402

Extracting transport parameters in GaAs nanopillars grown by selective-area epitaxy.  

PubMed

We investigate the transport properties in p-type GaAs nanopillars (NPs) grown on GaAs(111) B substrates using selective-area epitaxy by studying single-NP field-effect transistors. Experimental results indicate that normalized resistance and field-effect mobility are highly sensitive to NP dimensions. Both in situ and ex situ chemical surface passivation techniques are found to significantly improve conductivity and mobility, especially for the smaller diameter NPs. A semi-empirical model based on diameter dependent mobility is used to extract actual doping levels and surface state density by fitting normalized resistance as a function of NP diameter. Surface state densities before and after passivation are found to be 5 × 10(12) cm(-2) eV(-1) and 7 × 10(10) cm(-2) eV(-1), respectively. PMID:22349093

Lin, Andrew; Shapiro, Joshua N; Senanayake, Pradeep N; Scofield, Adam C; Wong, Ping-Show; Liang, Baolai; Huffaker, Diana L

2012-02-21

403

Monolithic cryogenic preamplifiers based on large gate-area GaAs MESFETs  

SciTech Connect

Monolithic preamplifiers using large gate-area Gallium-Arsenide Metal-Semiconductor Field-Effect Transistors (GaAs MESFETs) at the input have been designed and fabricated using an ion-implanted GaAs process. Large gate-area is necessary to obtain low series noise. A differential voltage-sensitive preamplifier has at the input two MESFETs with a gate width W = 6,000 {micro}m, it is fully DC coupled, has a large common-mode rejection ratio (CMRR) and dissipates low power at 4 K. Dual current-sensitive preamplifiers using at the input MESFETs with W = 24,000 {micro}m, designed for the readout of noble liquid calorimeters, have been integrated in a single chip. Recent tests with a LAr calorimeter prototype demonstrated strong noise reduction compared to previous state-of-the-art hybrid readout circuits. Radiation damage tests have been performed at cold on the current-sensitive preamplifier chips.

Camin, D.V.; Fedyakin, N.; Pessina, G.; Previtali, E. [Dipartimento di Fisica dell`Universita, Milano (Italy)]|[Inst. Nazionale di Fisica Nucleare, Milano (Italy)

1995-08-01

404

A highly selective, chlorofluorocarbon-free GaAs on AlGaAs etch  

SciTech Connect

A highly selective reactive ion etching process using SiCl[sub 4], CF[sub 4], O[sub 2], and He is reported. The selectivity of the etch, which is adjustable, ranges from 308:1 to 428:1 for GaAs to Al[sub 0.11]Ga[sub 0.89]As. This variability in selectivity is achieved by adjusting the helium flow rate. One very attractive feature of this etch is that it uses no chlorofluorocarbons and therefore complies with future bans on these substances imposed at both federal and corporate levels. The etch is demonstrated on a GaAs field effect transistor structure with an underlying Al[sub 0.11]Ga[sub 0.89]As stop-etch layer. The etch can be used for both anisotropic and isotropic applications.

Smith, L.E. (AT and T Bell Lab., Breinigsville, PA (United States). Solid State Technology Center)

1993-07-01

405

GaAs MOEMS Technology  

SciTech Connect

Many MEMS-based components require optical monitoring techniques using optoelectronic devices for converting mechanical position information into useful electronic signals. While the constituent piece-parts of such hybrid opto-MEMS components can be separately optimized, the resulting component performance, size, ruggedness and cost are substantially compromised due to assembly and packaging limitations. GaAs MOEMS offers the possibility of monolithically integrating high-performance optoelectronics with simple mechanical structures built in very low-stress epitaxial layers with a resulting component performance determined only by GaAs microfabrication technology limitations. GaAs MOEMS implicitly integrates the capability for radiation-hardened optical communications into the MEMS sensor or actuator component, a vital step towards rugged integrated autonomous microsystems that sense, act, and communicate. This project establishes a new foundational technology that monolithically combines GaAs optoelectronics with simple mechanics. Critical process issues addressed include selectivity, electrochemical characteristics, and anisotropy of the release chemistry, and post-release drying and coating processes. Several types of devices incorporating this novel technology are demonstrated.

SPAHN, OLGA B.; GROSSETETE, GRANT D.; CICH, MICHAEL J.; TIGGES, CHRIS P.; RENO, JOHN L.; PEAKE, GREGORY M.; KLEM, JOHN F.; LEAN, JEN; FULLER, CHARLES T.; BURKHART, JEFF; BAUER, THOMAS; SULLIVAN, CHARLES T.

2003-03-01

406

Validity of the quasi-transparent model of the current injected into heavily doped emitters of bipolar devices  

Microsoft Academic Search

A simple criterion that permits one to assess the accuracy of the calculation of the current injected into a heavily doped emitter using the quasi-transparent model is presented. The criterion provides an upper limit of the error incurred by the approximation when com- pared to an exact computer solution, without requiring any additional calculations. The gain of a bipolar transistor

JESUS A. DEL ALAMO; RICHARD M. SWANSON

1987-01-01

407

The Effects of Hydrogen in Hermetically Sealed Packages on the Total Dose and Dose Rate Response of Bipolar Linear Circuits  

Microsoft Academic Search

It is demonstrated with test transistors and circuits that a small amount of hydrogen trapped in hermetically sealed packages can significantly degrade the total dose and dose rate response of bipolar linear microelectronics. In addition, we show that when exposed to an atmosphere of 100% molecular hydrogen dies with silicon nitride passivation are unaffected, whereas dies with silicon carbide or

Ronald L. Pease; Dale G. Platteter; Gary W. Dunham; John E. Seiler; Philippe C. Adell; Hugh J. Barnaby; Jie Chen

2007-01-01

408

Exciton optoelectronic transistor.  

PubMed

We demonstrate experimental proof of principle for an optoelectronic transistor based on the modulation of exciton flux via gate voltage. The exciton optoelectronic transistor (EXOT) implements electronic operation on photons by using excitons as intermediate media; the intensity of light emitted at the optical output is proportional to the intensity of light at the optical input and is controlled electronically by the gate. We demonstrate a contrast ratio of 30 between an on state and an off state of the EXOT and its operation at speeds greater than 1 GHz. Our studies also demonstrate high-speed control of both the flux and the potential energy of excitons on a time scale much shorter than the exciton lifetime. PMID:17767273

High, A A; Hammack, A T; Butov, L V; Hanson, M; Gossard, A C

2007-09-01

409

Chemoresponsive monolayer transistors  

PubMed Central

This work details a method to make efficacious field-effect transistors from monolayers of polycyclic aromatic hydrocarbons that are able to sense and respond to their chemical environment. The molecules used in this study are functionalized so that they assemble laterally into columns and attach themselves to the silicon oxide surface of a silicon wafer. To measure the electrical properties of these monolayers, we use ultrasmall point contacts that are separated by only a few nanometers as the source and drain electrodes. These contacts are formed through an oxidative cutting of an individual metallic single-walled carbon nanotube that is held between macroscopic metal leads. The molecules assemble in the gap and form transistors with large current modulation and high gate efficiency. Because these devices are formed from an individual stack of molecules, their electrical properties change significantly when exposed to electron-deficient molecules such as tetracyanoquinodimethane (TCNQ), forming the basis for new types of environmental and molecular sensors.

Guo, Xuefeng; Myers, Matthew; Xiao, Shengxiong; Lefenfeld, Michael; Steiner, Rachel; Tulevski, George S.; Tang, Jinyao; Baumert, Julian; Leibfarth, Frank; Yardley, James T.; Steigerwald, Michael L.; Kim, Philip; Nuckolls, Colin

2006-01-01

410

Gallium nitride based transistors  

Microsoft Academic Search

An overview is presented of progress in GaN electronic devices along with recent results from work at UCSB. From 1995 to 2001, the power performance of AlGaN\\/GaN high electron mobility transistors (HEMT) improved from 1.1 to 11 W mm-1, respectively. The disadvantage of the low thermal conductivity of the sapphire substrate was mitigated by flip-chip bonding onto AlN substrates, yielding

H. Xing; S. Keller; Y.-F. Wu; L. McCarthy; I. P. Smorchkova; D. Buttari; R. Coffie; D. S. Green; G. Parish; S. Heikman; L. Shen; N. Zhang; J. J. Xu; B. P. Keller; S. P. Den Baars; U. K. Mishra

2001-01-01

411

Spectroscopy of a GaAs Double Dot Qubit with Dispersive Readout  

NASA Astrophysics Data System (ADS)

We report microwave spectroscopy of a GaAs double dot qubit device using the dispersive gate sensor (DGS) readout technique. In contrast to charge sensing methods based on quantum point contacts (QPCs) or single electron transistors (SETs), the DGS detection method senses the tunneling of charge between states that are near degenerate in energy. Microwave excitation applied to the surface gates enables this readout approach to resolve low energy spectroscopic features not apparent in transport or standard charge sensing measurements. We discuss the origin of these features and the use of this technique for characterizing semiconductor qubit systems.

Colless, James; Mahoney, Alice; Croot, Xanthe; Hornibrook, John; Doherty, Andrew; Stace, Tom; Lu, Hong; Gossard, Art; Reilly, David

2013-03-01

412

Staging Bipolar Disorder  

Microsoft Academic Search

The purpose of this study was to analyze the evidence supporting a staging model for bipolar disorder. The authors conducted\\u000a an extensive Medline and Pubmed search of the published literature using a variety of search terms (staging, bipolar disorder,\\u000a early intervention) to find relevant articles, which were reviewed in detail. Only recently specific proposals have been made\\u000a to apply clinical

Eduard Vieta; M. Reinares; A. R. Rosa

2011-01-01

413

Treatment of Bipolar Depression  

Microsoft Academic Search

\\u000a The challenge of treating depression in patients with bipolar illness has been both underestimated and understudied for a\\u000a variety of reasons. The role of traditional unimodal antidepressants in bipolar illness had been highly controversial, and\\u000a now with the publication of the results of a clinical trial addressing the issue (1) in the NEJM, the entire area needs to be reevaluated.

Robert M. Post

414

Atomic-scale determination of band offsets at the Gd2O3/GaAs (100) hetero-interface using scanning tunneling spectroscopy  

NASA Astrophysics Data System (ADS)

Direct measurements of band profile and band offsets across the Gd2O3/GaAs(100) hetero-interface have been performed using cross-sectional scanning tunneling microscopy and spectroscopy. The spatial variation of the local density of states with atomic precision revealed the interfacial band alignment in this model high-?/III-V system. In conjunction with the theoretical modeling, the band offsets for both conduction and valence states are identified, revealing critical information about the electrostatic potential landscape of the GaAs semiconductor transistor with a Gd2O3 gate dielectric.

Chiu, Y. P.; Huang, B. C.; Shih, M. C.; Shen, J. Y.; Chang, P.; Chang, C. S.; Huang, M. L.; Tsai, M.-H.; Hong, M.; Kwo, J.

2011-11-01

415

Lateral Current Confinement Determines Silicon Avalanche Transistor Operation in Short-Pulsing Mode  

Microsoft Academic Search

The transient in a Si bipolar junction transistor was investigated in high-current short-pulsing ( 2 ns) mode both experimentally and numerically. A comparison of measured and simulated waveforms clearly showed that only a small fraction of the perimeter of the emitter-base interface (in the lateral direction) takes part in the switching transient when a capacitor of relatively small value (80

Guoyong Duan; Sergey N. Vainshtein; Juha T. Kostamovaara

2008-01-01

416

Development of a planar heterojunction biopolar transistor for very high speed logic  

Microsoft Academic Search

Graded regions of n-(Ga,In)As and p-Ga(As,Sb) were incorporated side-by-side as emitter and base contacts, respectively, into an npn (Al,Ga)As\\/GaAs heterostructure bipolar transistor (HBT). The process involved two separate MBE growths, leading to base contact regions that were self-aligned to the emitter mesas. The devices could be easily probed with pressure contacts even prior to any metallization, and excellent characteristics were

Stephen I. Long; Herbert Kroemer; M. A. Rao

1986-01-01

417

Amorphous-Si emitter heterojunction UHF power transistors for handy transmitter  

Microsoft Academic Search

A UHF silicon heterojunction bipolar power transistor with a heavily doped amorphous-silicon emitter is reported. The fabrication process utilized an improved glow discharge technique. The deposition rate of amorphous silicon is 0.3-0.4 Ĺ\\/s, which is slower than that of conventional a-Si:H. The average carrier density in the amorphous-silicon film is estimated to be about 1.5×1019 cm-3. The present device can

Y.-S. Wang; X. M. Zhang; W. W. Sheng; X. W. Wang

1990-01-01

418

Development of a one transistor dynamic RAM for the AlGaAs\\/GaAs HIGFET technology  

Microsoft Academic Search

Modern VLSI integrated systems normally require large dynamic memory registers. To date, there has been little progress toward developing such memory elements for the GaAs heterojunction field effect transistor (HIGFET) technology. Toward this goal, we have studied the long term retention of minority carriers in potential wells at the AlGaAs\\/GaAs interface. Using a deep depletion capacitance-voltage (C-V) technique, we have

M. R. Melloch; Q.-D. Qian

1986-01-01

419

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

420

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

421

Gate-all-around polycrystalline-silicon thin-film transistors with self-aligned grain-growth nanowire channels  

NASA Astrophysics Data System (ADS)

In this letter, gate-all-around (GAA) polycrystalline silicon thin-film transistors (TFTs) with self-aligned grain-growth channels were fabricated using excimer laser crystallization (ELC) on a recessed-nanowire (RN) structure. Via the RN structure constructed by a simple sidewall-spacer formation, location-controlled nucleation and volume-confined lateral grain growth within the RN body during ELC process have been demonstrated with only one perpendicular grain boundary in each nanowire channel. Because of the high-crystallinity channel together with GAA operation mode, the proposed GAA-RN TFTs show good device integrity of lower threshold voltage, steeper subthreshold slope, and higher field-effect mobility as compared with the conventional planar counterparts.

Liao, Ta-Chuan; Kang, Tsung-Kuei; Lin, Chia-Min; Wu, Chun-Yu; Cheng, Huang-Chung

2012-02-01

422

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

423

Genetics of bipolar disorder  

PubMed Central

Bipolar disorder (also known as manic depressive illness) is a complex genetic disorder in which the core feature is pathological disturbance in mood (affect) ranging from extreme elation, or mania, to severe depression usually accompanied by disturbances in thinking and behaviour. The lifetime prevalence of 1% is similar in males and females and family, twin, and adoption studies provide robust evidence for a major genetic contribution to risk. There are methodological impediments to precise quantification, but the approximate lifetime risk of bipolar disorder in relatives of a bipolar proband are: monozygotic co-twin 40-70%; first degree relative 5-10%; unrelated person 0.5-1.5%. Occasional families may exist in which a single gene plays the major role in determining susceptibility, but the majority of bipolar disorder involves the interaction of multiple genes (epistasis) or more complex genetic mechanisms (such as dynamic mutation or imprinting). Molecular genetic positional and candidate gene approaches are being used for the genetic dissection of bipolar disorder. No gene has yet been identified but promising findings are emerging. Regions of interest identified in linkage studies include 4p16, 12q23-q24, 16p13, 21q22, and Xq24-q26. Chromosome 18 is also of interest but the findings are confusing with up to three possible regions implicated. To date most candidate gene studies have focused on neurotransmitter systems influenced by medication used in clinical management of the disorder but no robust positive findings have yet emerged. It is, however, almost certain that over the next few years bipolar susceptibility genes will be identified. This will have a major impact on our understanding of disease pathophysiology and will provide important opportunities to investigate the interaction between genetic and environmental factors involved in pathogenesis. This is likely to lead to major improvements in treatment and patient care but will also raise important ethical issues that will need to be addressed.???Keywords: bipolar disorder; manic depressive illness

Craddock, N.; Jones, I.

1999-01-01

424

Antiphase boundaries in GaAs  

Microsoft Academic Search

Antiphase boundaries in GaAs have been produced by growing the GaAs on 001 plane-type Ge substrates. The GaAs was grown by the technique of organometallic vapor phase epitaxy to a thickness in excess of 1 micron. The antiphase boundaries are shown to be faceted with facets parallel to the 110 planes being particularly common. The rigid-body translation at the different

N.-H. Cho; B. C. de Cooman; C. B. Carter; R. Fletcher; D. K. Wagner

1985-01-01

425

Antiphase boundaries in GaAs  

Microsoft Academic Search

Antiphase boundaries in GaAs have been produced by growing the GaAs on {001} Ge substrates. The GaAs was grown by the technique of organometallic vapor phase epitaxy to a thickness in excess of 1 ?m. The antiphase boundaries are shown to be faceted with facets parallel to the {110} planes being particularly common. The rigid-body translation at the different facet

N.-H. Cho; B. C. De Cooman; C. B. Carter; R. Fletcher; D. K. Wagner

1985-01-01

426

Neutron damage equivalence in GaAs  

NASA Astrophysics Data System (ADS)

A 1-MeV neutron damage equivalence methodology and damage function have been developed for GaAs based on a recoil-energy dependent damage efficiency and the displacement kerma. This method, developed using lifetime degradation in GaAs LEDs in a variety of neutron spectra, is also shown to be applicable to carrier removal. A validated methodology, such as this, is required to ensure and evaluate simulation fidelity in the neutron testing of GaAs semiconductors.

Griffin, P. J.; Kelly, J. G.; Luera, T. F.; Barry, A. L.; Lazo, M. S.

1991-12-01

427

All-optical excitonic transistor.  

PubMed

We demonstrate experimental proof of principle for all-optical excitonic transistors where light controls light by using excitons as an intermediate medium. The principle of operation of all-optical excitonic transistors is based on the control of exciton fluxes by light. PMID:20479817

Kuznetsova, Y Y; Remeika, M; High, A A; Hammack, A T; Butov, L V; Hanson, M; Gossard, A C

2010-05-15

428

Thermal characterization of power transistors  

Microsoft Academic Search

The idealized concept of thermal resistance as applied to power transistors is discussed. This concept must be used with care because two of the basic assumptions made in applying the concept to these devices are not valid. Contrary to these assumptions, it is shown that 1) the junction temperature of a power transistor is never spatially uniform, and 2) no

FRANK F. OETTINGER; DAVID L. BLACKBURN; S. Rubin

1976-01-01

429

Recent developments in power transistors  

Microsoft Academic Search

Power transistors capable of providing five watts output are now in production. Because these units are relatively non-linear in their characteristics, large signal graphical analysis of their behavior is necessary. To facilitate this, the static characteristics of the grounded base, grounded emitter, and grounded collector circuits are presented for several temperatures. Since power transistors are seldom driven with a high

H. T. Mooers

1955-01-01

430

[High-frequency transistor tract for UHF therapy device].  

PubMed

The paper deals with the specific features of construction of a common circuit and individual units of high-frequency transistor tracts for physiotherapeutic UHF apparatuses whose design is a possible way of conversion of radioelectron equipment. The design of UHF tracts gives rise to some radio engineering problems due to the low output resistance of bipolar transistors and to the operational characteristics of physiotherapeutic equipment and, as a result, the load of the tract is a two-conductor long line loaded with complex resistance whose active part changes slightly and the reactive one varies very greatly. The structure of a high-frequency, which transfers power from the generator with external excitement to the active part of complex load by changing its reactive part in the wide range, was analyzed. It is shown that for reliable operation of the UHF apparatus, its tract should have a multichannel structure with subsequent summation of the power and automatic compensation of the reactive component of alternating load. This provides a measuring mode for the power connected to the patient. The tract structure in question may serve the basis for the designing transistor physiotherapy apparatuses of average and high power (Poutput = 50-400 W). PMID:9791855

Tamarchak, D Ia

431

Transparent metal oxide nanowire transistors  

NASA Astrophysics Data System (ADS)

With the features of high mobility, a high electric on/off ratio and excellent transparency, metal oxide nanowires are excellent candidates for transparent thin-film transistors, which is one of the key technologies to realize transparent electronics. This article provides a comprehensive review of the state-of-the-art research activities that focus on transparent metal oxide nanowire transistors. It begins with the brief introduction to the synthetic methods for high quality metal oxide nanowires, and the typical nanowire transfer and printing techniques with emphasis on the simple contact printing methodology. High performance transparent transistors built on both single nanowires and nanowire thin films are then highlighted. The final section deals with the applications of transparent metal oxide nanowire transistors in the field of transparent displays and concludes with an outlook on the current perspectives and future directions of transparent metal oxide nanowire transistors.

Chen, Di; Liu, Zhe; Liang, Bo; Wang, Xianfu; Shen, Guozhen

2012-05-01

432

Integratable nanowire transistors.  

PubMed

We report a structure to control nanowire location and growth direction and demonstrate top-gated, metal-oxide-semiconductor, field-effect transistors (MOSFETs) using this structure. The nanowires wereengineered to grow against an oxide surface of a (001), silicon-on-insulator substrate, enabling straightforward fabrication of MOSFETs exhibiting an Io/Ioff ratio approximately 104 and a subthreshold slope of approximately 155 mV/decade. Though nanowires were engineered to grow in (110) directions, the nanowires still grew by the addition of {111) planes. PMID:19367850

Quitoriano, Nathaniel J; Kamins, Theodore I

2008-12-01

433

Bipolar disorder and substance abuse  

Microsoft Academic Search

Substance use disorders are overrepresented in individuals with bipolar and bipolar spectrum disorders. Although awareness of this phenomenon has increased over the past 20 years, few empirically based treatment strategies have been developed for this challenging patient population. This review examines the relationship between bipolar and substance use disorders and treatment options that have been studied in this patient population.

Frances R. Levin; Grace Hennessy

2004-01-01

434

The genetics of bipolar disorder  

Microsoft Academic Search

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

J. H. Barnett; J. W. Smoller

2009-01-01

435

Genetics of bipolar disorder.  

PubMed

Bipolar disorder (also known as manic depressive illness) is a complex genetic disorder in which the core feature is pathological disturbance in mood (affect) ranging from extreme elation, or mania, to severe depression usually accompanied by disturbances in thinking and behaviour. The lifetime prevalence of 1% is similar in males and females and family, twin, and adoption studies provide robust evidence for a major genetic contribution to risk. There are methodological impediments to precise quantification, but the approximate lifetime risk of bipolar disorder in relatives of a bipolar proband are: monozygotic co-twin 40-70%; first degree relative 5-10%; unrelated person 0.5-1.5%. Occasional families may exist in which a single gene plays the major role in determining susceptibility, but the majority of bipolar disorder involves the interaction of multiple genes (epistasis) or more complex genetic mechanisms (such as dynamic mutation or imprinting). Molecular genetic positional and candidate gene approaches are being used for the genetic dissection of bipolar disorder. No gene has yet been identified but promising findings are emerging. Regions of interest identified in linkage studies include 4p16, 12q23-q24, 16p13, 21q22, and Xq24-q26. Chromosome 18 is also of interest but the findings are confusing with up to three possible regions implicated. To date most candidate gene studies have focused on neurotransmitter systems influenced by medication used in clinical management of the disorder but no robust positive findings have yet emerged. It is, however, almost certain that over the next few years bipolar susceptibility genes will be identified. This will have a major impact on our understanding of disease pathophysiology and will provide important opportunities to investigate the interaction between genetic and environmental factors involved in pathogenesis. This is likely to lead to major improvements in treatment and patient care but will also raise important ethical issues that will need to be addressed. PMID:10465107

Craddock, N; Jones, I

1999-08-01

436

An integrated 20 GHz SiGe bipolar differential oscillator with high tuning range  

Microsoft Academic Search

A fully integrated, differential LC oscillator manufactured in Infineon's B7HF SiGe bipolar technology with an fT and fmax of 75 GHz is presented. The oscillator features a tank consisting of on-chip stripline inductors and the parasitic capacitances of the oscillator transistors. A tuning range of 14-21.5 GHz over bias current is achieved. The output buffer is inductively coupled to the

Klaus Ettinger; Markus Bergmayr; Harald Pretl; Wolfgang Thomann; Josef Fenk; Robert Weigel

2000-01-01

437

A High Resolution Cmos Imager With Active Pixel Using Capacitively Coupled Bipolar Operation  

Microsoft Academic Search

The active pixel sensor technology promises high performance than conventional CCD imagers. This paper reports a new high resolution CMOS imager with one transistor active pixel sensing based on capacitorcoupled bipolar action. The base capacitor is pulsed negatively for image integration and positively for image sensing. The pixel size is 5.9um x 5.9um (on 0.8um design rule). The prototype imager

Min-hwa Chi; Tobi Delbruck; Nick Mascarenhas; Albert Bergemont; Carver Mead

1997-01-01

438

BCD (Bipolar-CMOS-DMOS) technology trends for power management IC  

Microsoft Academic Search

This paper reviews the technology trends of BCD (Bipolar-CMOS-DMOS) technology in terms of voltage capability, switching speed of power transistor, and high integration of logic CMOS for SoC (System-on-Chip) solution requiring high-voltage devices. Recent trends such like modularity of the process, power metal routing, and high-density NVM (Non-Volatile Memory) are also discussed. Power management is becoming highly growing market in

Il-Yong Park; Yong-Keon Choi; Kwang-Young Ko; Sang-Chul Shim; Bon-Keun Jun; Nam-Chil Moon; Nam-Joo Kim; Kwang-Dong Yoo

2011-01-01

439

Analysis and control of floating-body bipolar effects in fully depleted submicrometer SOI MOSFET's  

Microsoft Academic Search

Floating-body effects triggered by impact ionization in fully depleted submicrometer silicon-on-insulator (SOI) MOSFETs are analyzed based on two-dimensional device simulations. The parasitic bipolar junction transistor (BJT) effects are emphasized, but the kink effect and its disappearance in the fully depleted device are first explained physically to provide a basis for the BJT analysis. The results of simulations of the BJT-induced

Jin-Young Choi; Jerry G. Fossum

1991-01-01

440

2-22 GHz low phase noise silicon bipolar YIG tuned oscillator using composite feedback  

Microsoft Academic Search

The authors present a fundamental YIG tuned oscillator which covers the frequency range of 2 to 22 GHz, using a high-frequency silicon bipolar transistor and a single YIG sphere. A unique composite feedback approach has been utilized to demonstrate a minimum of 10-dBm power output and phase noise of -95 dBc\\/Hz at 10 kHz across most of the band. The

A. P. S. Khanna; J. Buenrostro

1992-01-01

441

Temperature investigation of the gate-drain diode of power GaAs MESFET with low-temperature-grown (Al)GaAs passivation  

Microsoft Academic Search

We have investigated the breakdown-temperature characteristics of the gate-drain diode of a GaAs metal semiconductor field-effect transistor with low-temperature-grown (LTG) GaAs\\/AlGaAs passivation. An anomalous decrease in the breakdown voltage as a function of the temperature is observed. This behavior leads us to propose an explanation of how LTG passivation leads to a high breakdown voltage at room temperature; and this

L.-W. Yin; N. X. Nguyen; Y. Hwang; J. P. Ibbetson; R. M. Kolbas; A. C. Gossard; U. K. Mishra

1993-01-01

442

A 2.2-V operation, 2.4GHz single-chip GaAs MMIC transceiver for wireless applications  

Microsoft Academic Search

A 2.2-V operation, single-chip GaAs MMIC transceiver has been successfully developed for 2.4-GHz-band wireless applications such as wireless local area network terminals. The chip is fabricated using a planar self-aligned gate field-effect transistor. To generate sufficient negative voltage for gate-biasing and to enhance switch power handling capability under a 2.2-V supply, a newly designed negative voltage generator with a voltage

Kazuya Yamamoto; Takao Moriwaki; Takayuki Fujii; Jun Otsuji; Miyo Miyashita; Yukio Miyazaki; Kazuo Nishitani

1999-01-01

443

High-efficient class F GaAs FET amplifiers operating with very low bias voltages for use in mobile telephones at 1.75 GHz  

Microsoft Academic Search

High-efficiency class F GaAs power FET amplifiers working with a very low drain bias voltage of 3 V, for use in portable telephones, are reported. The transistor used has an optimized gate periphery of 2000 mm and a gate length of 0.7 ?m. Under class F operation with a drain voltage of 3 V, it has demonstrated an output power

C. Duvanaud; S. Dietsche; G. Pataut; J. Obregon

1993-01-01

444

Impact ionization in GaAs MESFETs  

Microsoft Academic Search

A method to measure impact ionization current in GaAs MESFETs is presented. The impact ionization current is then used to calculate the maximum electric field in the channel and the impact ionization coefficient. Data for the electron impact ionization coefficient in ?110? GaAs are extended beyond previous studies by five orders of magnitude. Impact ionization is taken into account in

Kelvin Hui; Chenming Hu; Peter George; PING K. KO

1990-01-01

445

Bipolar Preference Problems  

Microsoft Academic Search

ences, that we call bipolar problems. Although seemingly specular notions, these two kinds of preferences should be dealt differently to obtain the desired natural behaviour. In fact, assume, for example, to have a scenario with two objects A and B. If we like both A and B, i. e., if we give to A and B positive preferences, then the

Stefano Bistarelli; Maria Silvia Pini; Francesca Rossi; Kristen Brent Venable

2006-01-01

446

Ziprasidone in bipolar disorder.  

PubMed

Ziprasidone is a second-generation antipsychotic currently marketed for the treatment of schizophrenia and bipolar mania. It has a unique receptor profile that includes high-affinity antagonist activity at 5-hydroxytryptamine (5-HT) 2A, D2, 1D and 2C receptors, a potent agonist activity at 5-HT1A receptors and a relatively high affinity for the 5-HT and noradrenaline transporters. The efficacy of ziprasidone in bipolar mania (current episode, manic or mixed) has been well demonstrated in three placebo-controlled trials. In a three-arm controlled study, ziprasidone was shown to be efficacious in dysphoric mania, whereas haloperidol was comparable to placebo. Open-label treatment for up to 52 weeks supported the sustained efficacy of ziprasidone in bipolar disorder. Combined with lithium, ziprasidone has been shown to be efficacious as an augmenting agent in the acute treatment of mania, with sustained efficacy up to 1 year. Ziprasidone was very well tolerated by patients with bipolar disorder and did not cause increased weight, glucose or lipid levels. PMID:16732708

Versiani, Marcio

2006-06-01

447

A Study Of Gate-All-Around Transistors By Electron Tomography  

NASA Astrophysics Data System (ADS)

Gate-all-around (GAA) SiGe nanowire transistor structures have been studied using high angle annular dark field (HAADF) STEM tomography. Sample preparation has been optimized by isolating single devices in needle-shaped specimens, using annular milling in the focused ion beam (FIB). Using this technique, images can be acquired over a tilt range up to +/-80°. Two dimensional simulations are used lo establish the optimum orientation for devices in this sample geometry. Tomograms are presented, and the impact of the ``missing wedge'' on the reconstruction is assessed, again with reference to two dimensional simulations.

Cherns, P. D.; Lorut, F.; Beçu, S.; Dupré, C.; Tachi, K.; Cooper, D.; Chabli, A.; Ernst, T.

2009-09-01

448

Terahertz detection with field-effect-transistors via bulk plasmon-assisted self-mixing  

NASA Astrophysics Data System (ADS)

We previously reported resonant photovoltaic terahertz detection via bulk plasmons in GaAs field-effect-transistors (FETs). Here, we introduce a device model which incorporates the microscopic dynamics of terahertz-field-driven electrons in the FET channel, resonant excitation of three dimensional (bulk) plasmons, and self-mixing theory of Lisauskas and Pfeiffer. The resulting model can simulate our experimental results and implies a bulk plasmon-assisted terahertz self-mixing process occurs in the FET-based terahertz detectors. The model also suggests three factors are important to improving the device performance ? power coupling efficiency, self-mixing efficiency, and resonance with bulk plasmons.

Kim, Sangwoo; Sherwin, Mark S.

2010-04-01

449

500 GHz GaAs MMIC sampling wafer probe  

Microsoft Academic Search

A 500 GHz bandwidth GaAs MMIC sampling wafer probe is reported which incorporates a mechanical flexure and a micromachined GaAs IC for time domain on-wafer measurements. The GaAs IC incorporates a novel high speed pulse sharpener and a two-diode sampling bridge with a micromachined GaAs tip.

M. S. Shakouri; A. Black; B. A. Auld; D. M. Bloom

1993-01-01

450

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

451

Reliability Physics Studies on Transistors.  

National Technical Information Service (NTIS)

The report describes work on the second breakdown phenomenon in transistors. Section 1 deals with a comparison of electrical test methods for observing the onset of the thermal instability which leads to second breakdown. Two types of pulsed emitter curre...

R. M. Scarlett G. C. Riddle

1966-01-01

452

Interface Doping of MNOS Transistors.  

National Technical Information Service (NTIS)

The objective of this program is threefold: First to survey interface dopants suitable for use in MNOS nonvolatile storage transistors, to identify optimum dopant materials, concentrations, and deposition techniques, and to evaluate the write characterist...

C. A. Neugebauer M. M. Barnicle

1978-01-01

453

Field-Effect Superconducting Transistor.  

National Technical Information Service (NTIS)

The operating principle and characteristics of a field-effect superconducting transistor using superconductors and a semiconductor were studied. For the application of superconducting materials to electronics, it is necessary to develop a superconducting ...

T. Nishino K. Yagi U. Kawabe

1990-01-01

454

High transconductance organic electrochemical transistors.  

PubMed

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

455

A Broadband Complementary Transistor Amplifier.  

National Technical Information Service (NTIS)

A two-stage NPN-PNP complementary transistor amplifier with great versatility over a broad frequency range is described herein. This circuit configuration provides high-input impedance and low-output impedance coupled with extremely stable gain characteri...

R. S. Hughes R. A. Mammano

1965-01-01

456

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.

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

2013-01-01

457

Production Engineering Measure. Microelement Transistors.  

National Technical Information Service (NTIS)

The purpose of this task was to establish a manufacturing capability for a broad line of microelement transistors commensurate with Micromodule Program requirements. Subcontractors were established to provide devices that could be hermetically packaged an...

1965-01-01

458

Memory device application of wide-channel in-plane gate transistors with type-II GaAsSb-capped InAs quantum dots  

NASA Astrophysics Data System (ADS)

We demonstrate room-temperature electron charging/discharging phenomena of InAs quantum dots using wide-channel in-plane gate transistors. The device based on type-II GaAsSb-capped InAs quantum dots exhibits both the longer charging and discharging times than those of the type-I counterpart with GaAs capping layers. The slow charge relaxation of GaAsSb-capped InAs quantum dots and simple architecture of in-plane gate transistors reveal the potential of this device architecture for practical memory applications.

Liao, Yu-An; Chao, Yi-Kai; Chang, Shu-Wei; Chang, Wen-Hao; Chyi, Jen-Inn; Lin, Shih-Yen

2013-09-01

459

Gate-enclosed NMOS transistors  

NASA Astrophysics Data System (ADS)

In order to quantitatively compare the design cost and performance of various gate styles, NMOS transistors with two-edged, annular and ring gate layouts were designed and fabricated by a commercial 0.35 ?m CMOS process. By comparing the minimum W/L ratios and transistor areas, it was found that either the annular layout or its ring counterpart incurs a higher area penalty that depends on the W/L ratio of the transistor to be designed. Furthermore, by comparing the output and transfer characteristics of the transistors and analyzing the popular existing methods for extracting the effective W/L ratio, it was shown that the mid-line approximation for annular NMOS could incur an error of more than 10%. It was also demonstrated that the foundry-provided extraction tool needs significant adaptation when being applied to the enclosed-gate transistors, since it is targeted only toward the two-edged transistor. A simple approach for rough extraction of the W/L ratio for the ring-gate NMOS was presented and its effectiveness was confirmed by the experimental results with an error up to 8%.

Xue, Fan; Ping, Li; Wei, Li; Bin, Zhang; Xiaodong, Xie; Gang, Wang; Bin, Hu; Yahong, Zhai

2011-08-01

460

A facile route to Si nanowire gate-all-around field effect transistors with a steep subthreshold slope  

NASA Astrophysics Data System (ADS)

We present a facile CMOS-compatible fabrication of lateral gate-all-around (GAA) field effect transistors (FETs) based on concentric Si-SiO2/N++Si core-multi-shell nanowires (NWs). Si-SiO2/N++Si core-multi-shell NWs were prepared by sequential Si NW growth, thermal oxidation and Si deposition processes in a single chamber. The GAA NW FET was then fabricated using the Si core, SiO2 inner-shell, N++ Si outer-shell as a channel, gate dielectric, and gate electrode, respectively. A one-step wet etching process was able to define the gate and source-drain contact regions. The SiNW GAA FET clearly exhibits a geometry-dependent gating effect and a steep subthreshold slope due to the low interface trapped charge density at the interface of the Si core and the SiO2 shell. Our proposed SiNW GAA structures offer new opportunities for low-energy-consumption digital device applications.We present a facile CMOS-compatible fabrication of lateral gate-all-around (GAA) field effect transistors (FETs) based on concentric Si-SiO2/N++Si core-multi-shell nanowires (NWs). Si-SiO2/N++Si core-multi-shell NWs were prepared by sequential Si NW growth, thermal oxidation and Si deposition processes in a single chamber. The GAA NW FET was then fabricated using the Si core, SiO2 inner-shell, N++ Si outer-shell as a channel, gate dielectric, and gate electrode, respectively. A one-step wet etching process was able to define the gate and source-drain contact regions. The SiNW GAA FET clearly exhibits a geometry-dependent gating effect and a steep subthreshold slope due to the low interface trapped charge density at the interface of the Si core and the SiO2 shell. Our proposed SiNW GAA structures offer new opportunities for low-energy-consumption digital device applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr02552g

Lee, Jae-Hyun; Kim, Byung-Sung; Choi, Soon-Hyung; Jang, Yamujin; Hwang, Sung Woo; Whang, Dongmok

2013-09-01

461

Feasibility study of the combination of MNOS elements and bipolar TTL peripherals on an LSI circuit chip  

NASA Astrophysics Data System (ADS)

The objective of this research was to obtain radiation, reliability and performance data on monolithic test structures containing MNOS memory transistors and n-p-n bipolar transistors. The data indicates that the devices performed acceptably at 100,000 rads (Si). Thin-oxide structures performed satisfactorily after exposure to 500,000 rads(Si). Thus, if these devices were combined into an EAROM memory circuit, a hardness level above 100,000 rads should result. Performance, reliability and breakdown characteristics were measured and are consistent with parameter values that would be useful for an EAROM.

Cunniff, K.

1980-08-01

462

Hexagonal structures in GaAs nanowhiskers  

NASA Astrophysics Data System (ADS)

We have studied the crystal structure of GaAs nanowhiskers grown by molecular beam epitaxy (MBE) on gold-activated GaAs(111)B substrates. The results of reflection high-energy electron diffraction and transmission electron microscopy showed that the MBE-grown GaAs nanowhiskers can form a crystal structure of sphalerite, wurtzite, or an intermediate phase close to 4H polytype, depending on the deposition conditions and the size of catalyst droplets. The results are interpreted within the framework of a thermodynamic model.

Soshnikov, I. P.; Cirlin, G. E.; Sibirev, N. V.; Dubrovskii, V. G.; Samsonenko, Yu. B.; Litvinov, D.; Gerthsen, D.

2008-06-01

463

Hexagonal structures in GaAs nanowhiskers  

Microsoft Academic Search

We have studied the crystal structure of GaAs nanowhiskers grown by molecular beam epitaxy (MBE) on gold-activated GaAs(111)B\\u000a substrates. The results of reflection high-energy electron diffraction and transmission electron microscopy showed that the\\u000a MBE-grown GaAs nanowhiskers can form a crystal structure of sphalerite, wurtzite, or an intermediate phase close to 4H polytype,\\u000a depending on the deposition conditions and the size

I. P. Soshnikov; G. E. Cirlin; N. V. Sibirev; V. G. Dubrovskii; Yu. B. Samsonenko; D. Litvinov; D. Gerthsen

2008-01-01

464

Update on pediatric bipolar disorder  

Microsoft Academic Search

Children and adolescents with a bipolar disorder experience mood dysregulation that is often chronic with little interepisodic\\u000a recovery. Although bipolar disorder in youth is recognized by more and more clinicians, much is still not known regarding\\u000a how best to accurately diagnose and effectively treat it. As a result, children and adolescents with bipolar disorder are\\u000a often symptomatic for long periods

Lisa D. Townsend; Christine A. Demeter; Michael Wilson; Robert L. Findling

2007-01-01

465

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

466

Bipolar and unipolar depression.  

PubMed

Since Kraepelin grouped affective disorders under the title of 'manic-depressive insanity', there has been controversy over whether the bipolar and unipolar entities within this are distinct affective disorders or whether they are merely two ends of an affective continuum. In order to bring some clarity and goal-posts to this argument, we define the criteria that must be fulfilled by diseases in order to be considered as part of a spectrum. We analyse bipolar disorder and major depressive disorder with respect to these criteria and find the model fits in many respects but fails to account for either the poor correlation in severity of manic and depressive symptoms or for the apparent discontinuity in the distribution of familial mania. A one-dimensional spectrum is thus too simple and a two-dimensional approach is required; this also fits much better with our current understanding of the genetic picture. PMID:22945198

Rogers, Jonathan; Agius, Mark

2012-09-01

467

Neuroprotection in Bipolar Depression  

Microsoft Academic Search

\\u000a The past 10 years have seen a growth of therapeutic options for bipolar depression. Evidence for the clinical and neuroprotective\\u000a effects of these treatments is reviewed in this chapter, including lamotrigine, pramipexole, modafinil, and atypical antipsychotics.\\u000a Their neuroprotective profiles are compared to the better established effects of lithium and valproate, which include upregulation\\u000a of brain-derived neurotrophic factor (BDNF) and B-cell

Chris B. Aiken

468

Pharmacogenetics of bipolar disorder  

Microsoft Academic Search

To review the pharmacogenetics of bipolar disorders, the authors searched databases for genetic association and linkage studies\\u000a involving response to long-term prophylactic lithium treatment, as well as treatment with antidepressants or clozapine. Significant\\u000a ethnic variations in the metabolism and efficacy of antidepressants, as well as clozapine, have been reported by several groups.\\u000a Systematic studies suggest that that genetic factors affect

Hader A. Mansour; Martin Alda; Vishwajit L. Nimgaonkar

2002-01-01

469

Field effect transistor-self electrooptic effect device (FET-SEED) differential transimpedance amplifiers for two-dimensional optical data links  

Microsoft Academic Search

A 4×18 two-dimensional array of GaAs FET-SEED (field effect transistor-self electrooptic effect device) differential transimpedence receivers has been fabricated for application in massively parallel optical data link board-to-board interconnections. Several FET-SEED receiver arrays were tested and displayed a mean response of ~0.7 mV\\/?W, and were capable of >100 Mbps per channel operation. The mean receiver sensitivity for a BER of

Robert A. Novotny; Michael J. Wojcik; Anthony L. Lentine; Leo M. F. Chirovsky; L. A. D'Asaro; M. W. Focht; G. Guth; K. G. Glogovsky; R. Leibenguth; M. T. Asom; J. M. Freund

1995-01-01

470

Stable gallium arsenide MIS capacitors and MIS field effect transistors by (NH4)2Sx treatment and hydrogenation using plasma deposited silicon nitride gate insulator  

Microsoft Academic Search

The beneficial effects of sulfur passivation of gallium arsenide (GaAs) surface by (NH4)2Sx chemical treatment and by hydrogenation of the insulator-GaAs interface using the plasma-enhanced chemical vapor-deposited (PECVD) silicon nitride gate dielectric film as the source of hydrogen are illustrated by fabricating Al\\/PECVD silicon nitride\\/n-GaAs MIS capacitors and metal insulator semiconductor field effect transistors (MISFET). Post metallization annealing (PMA) at

Kariyadan Remashan; K. N. Bhat

2002-01-01

471

Bipolar disorder and substance abuse.  

PubMed

Substance use disorders are overrepresented in individuals with bipolar and bipolar spectrum disorders. Although awareness of this phenomenon has increased over the past 20 years, few empirically based treatment strategies have been developed for this challenging patient population. This review examines the relationship between bipolar and substance use disorders and treatment options that have been studied in this patient population. First, we examine the high prevalence rates of substance use disorders in individuals diagnosed with bipolar disorder, the common problems associated with establishing a bipolar disorder diagnosis in individuals who abuse substances, the possible explanations for the frequent coexistence of bipolar and substance use disorders, and the negative effect of substance abuse on the course of and treatment outcomes for bipolar disorder. The review then focuses on treatment approaches for this patient population, including integrated group therapy for co-occurring bipolar and substance use disorders and pharmacotherapies that target both disorders. Finally, we present suggestions for medications that might be tested for their efficacy in treating both disorders in specific subgroups of patients with bipolar and substance use disorders. PMID:15556118

Levin, Frances R; Hennessy, Grace

2004-11-15

472

New Passivation Methods for GaAs.  

National Technical Information Service (NTIS)

The fabrication of high-quality oxides on GaAs with good electrical interface properties was investigated. The physical properties of our new anodix anodic oxidation were investigated by a systematic study of relevant parameters. The new electrolyte, term...

B. Bayraktaroglu A. Colquhoun A. F. A. B. El-Safti E. Kohn H. L. Hartnagel

1976-01-01

473

A 1 bit binary-decision-diagram adder circuit using single-electron transistors made by selective-area metalorganic vapor-phase epitaxy  

NASA Astrophysics Data System (ADS)

We demonstrate single-electron operation of a 1 bit adder circuit using GaAs single-electron tunneling transistors (SETs). GaAs dot and wire coupled structures for the fabrication of SETs were grown by a selective-area metalorganic vapor-phase epitaxy technique. The logic circuit was realized based on a binary decision diagram architecture using Coulomb blockade (CB) in GaAs dots and switching operations were achieved in a single-electron mode because of the CB effects. Through this architecture, a 1 bit adder circuit was realized with three SETs, two of which were for AND logic and one with two input gates for exclusive OR (XOR). Both AND and XOR operations were demonstrated at 1.9 K, which indicated successful fabrication of the 1 bit adder.

Miyoshi, Yoshihito; Nakajima, Fumito; Motohisa, Junichi; Fukui, Takashi

2005-07-01

474

Nanofluidic Transistor Circuits  

NASA Astrophysics Data System (ADS)

Non-equilibrium ion/fluid transport physics across on-chip membranes/nanopores is used to construct rectifying, hysteretic, oscillatory, excitatory and inhibitory nanofluidic elements. Analogs to linear resistors, capacitors, inductors and constant-phase elements were reported earlier (Chang and Yossifon, BMF 2009). Nonlinear rectifier is designed by introducing intra-membrane conductivity gradient and by asymmetric external depletion with a reverse rectification (Yossifon and Chang, PRL, PRE, Europhys Lett 2009-2011). Gating phenomenon is introduced by functionalizing polyelectrolytes whose conformation is field/pH sensitive (Wang, Chang and Zhu, Macromolecules 2010). Surface ion depletion can drive Rubinstein's microvortex instability (Chang, Yossifon and Demekhin, Annual Rev of Fluid Mech, 2012) or Onsager-Wien's water dissociation phenomenon, leading to two distinct overlimiting I-V features. Bipolar membranes exhibit an S-hysteresis due to water dissociation (Cheng and Chang, BMF 2011). Coupling the hysteretic diode with some linear elements result in autonomous ion current oscillations, which undergo classical transitions to chaos. Our integrated nanofluidic circuits are used for molecular sensing, protein separation/concentration, electrospray etc.

Chang, Hsueh-Chia; Cheng, Li-Jing; Yan, Yu; Slouka, Zdenek; Senapati, Satyajyoti

2012-02-01

475

Stable monolithic GaAs FET oscillator  

Microsoft Academic Search

A monolithic X-band GaAs FET oscillator has been developed. Passive circuit components are lumped capacitors and inductors on semi-insulating GaAs; the chip size is 1.2 x 1.4 sq mm. Stabilized with a Ba2Ti9O20 dielectric resonator, the oscillator delivers more than 30 mW output power at 10.8 GHz with a maximum chip efficiency of 20 percent. The frequency drift is better

C. Tsironis; C. Kermarrec; J. Faguet; P. Harrop

1982-01-01

476

Thermal fatigue in silicon power transistors  

Microsoft Academic Search

In silicon power transistor applications, thermal cycling of the transistor may activate a failure mechanism called thermal fatigue. This phenomenon is caused by the mechanical stresses set up by the differential in the thermal expansions of the various materials used in the assembly and heat sink of the transistor. Thermal fatigue often results in cracking of the silicon pellet or

G. A. Lang; B. J. Fehder; W. D. Williams

1970-01-01

477

Update: Researchers pencil in graphene transistors  

Microsoft Academic Search

Graphene, found in pencil marks, is a candidate material for making future transistors. It's extracted from graphite crystals using sticky tape. Graphene's weird electrical properties allow for smallest transistor yet. Silicon's remarkable run as ruler of the chip world may be nearing an end as engineers eventually lose the ability to make faster silicon transistors by making them smaller. In

Neil Savage

2008-01-01

478

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

479

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

480

Bipolar Disorder: an impossible diagnosis  

Microsoft Academic Search

Following the recent debates on the discrepancy between the predominant weight of bipolar disorder (BPD) in the clinical reality and its relatively low prevalence figures emerging from epidemiological surveys, the present paper contends the ability of current operational diagnostic system to properly detect the clinical entity of bipolar disorder. As an episode of mania\\/hypomania is the necessary requirement for a

Carlo Faravelli; Silvia Gorini Amedei; Maria Alessandra Scarpato; Luca Faravelli

2009-01-01

481

Uncertainty in bipolar preference problems  

Microsoft Academic Search

Preferences and uncertainty are common in many real-life problems. In this article, we focus on bipolar preferences and uncertainty modelled via uncontrollable variables, and we assume that uncontrollable variables are specified by possibility distributions over their domains. To tackle such problems, we concentrate on uncertain bipolar problems with totally ordered preferences, and we eliminate the uncertain part of the problem,

Stefano Bistarelli; Maria Silvia Pini; Francesca Rossi; Kristen Brent Venable

2011-01-01

482

Pediatric and Adolescent Bipolar Disorder  

Microsoft Academic Search

An increasing body of research suggests the existence of early onset childhood bipolar disorder. The population of pediatric bipolar illness may be small, but current research points to early misdiagnosis of ADD\\/ADHD, and that attention deficit disorder may masquerade as a harbinger of the mania to come. Since ADD\\/ADHD estimates range up to 10% of the school population, the notion

Lynn K. Akin

2001-01-01

483