Note: This page contains sample records for the topic gaas bipolar transistor from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

A charge sensitive preamplifier based on GaAs heterojunction bipolar transistors  

Microsoft Academic Search

Summary form only. The application of GaAs technology to particle physics experiments has been investigated. It appears that GaAs heterojunction bipolar transistors (HBT) might suit the requirements for the front end electronics, such as radiation hardness and adequate gm at very low current for low power dissipation and at fast shaping times. Since the operation of an HBT is similar

C. M. Buttar; S. Walker; K. Shankar

1992-01-01

2

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

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

3

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

4

Radiation effects in GaAs heterojunction bipolar transistors and silicon MOS capacitors  

SciTech Connect

Charge collection as well as total dose measurements have been carried out on variety of semiconductor test structures. Silicon and gallium arsenide devices have been selected for both types of studies. They include heterostructure GaAs bipolar junction transistors, and conventional and implanted MOS silicon capacitors. Alphas, protons, heavy ions, and neutrons were used to irradiate the electronic devices and a multichannel analyzer was used to study charge collection in their sensitive volumes using Pulse-height Analysis. Standard Americium 241 alpha sources were used for both, irradiating devices and system calibration. The results for charge collection were compared against the predictions coming out of the Monte Carlo simulation code CUPID developed by the same research group at Clarkson University. Cobalt 60 gammas have been used for irradiating the test structures in the total dose measurements. Analysis of the Capacitance-Voltage characteristic curves was the technique to study the charge build-up in the oxide layer. The devices were also total dosed.

Yaktieen, M.H.

1989-01-01

5

Analyses of the picosecond range transient in a high-power switch based on a bipolar GaAs transistor structure  

Microsoft Academic Search

The superfast (?200 ps) switching observed lately in a GaAs bipolar-junction transistor (BJT) structure is analyzed. Contrary to all known bipolar semiconductor switches, a superfast transient occurs in this GaAs BJT due to practically homogeneous and simultaneous high-rate carrier generation across the entire thickness of the blocking region. This generation is provided by a comb of powerfully avalanching Gunn domains

Sergey N. Vainshtein; Valentin S. Yuferev; Juha T. Kostamovaara

2005-01-01

6

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

NASA Astrophysics Data System (ADS)

GaAs delta-doped emitter bipolar junction transistors (?-BJT) with different emitter set-back layer thicknesses of 10 to 50 nm were fabricated to study the emitter set-back layer thickness effect on device dc performance. We found that the current gain decreases following decrease in the emitter set-back layer thickness. A detailed analysis was performed to explain this phenomenon, which is believed to be caused by reduction of the effective barrier height in the ?-BJT. This is due to change in the electric-field distribution in the delta-doped structure caused by the built-in potential of the base-emitter (B-E) junction. Considering the recombination and barrier height reduction effects, the thickness of the emitter set-back layer should be designed according to the B-E junction depletion width with a tolerance of +/-5 nm. The dc performance of a ?-BJT designed based on this criteria is compared to that of a Al0.25Ga0.75As/GaAs heterojunction bipolar transistor (HBT). Both devices employed base doping of 2×1019 cm-3 and base-to-emitter doping ratio of 40. Large emitter area (AE~1.6×10-5 cm-2) and small emitter area (AE~1.35×10-6 cm-2) device current gains of 40 and 20, respectively, were obtained in both types of transistors passivated by (NH4)2S treatment. The measured current gain of the GaAs ?-BJT is the highest reported for a homojunction device with such high base-to-emitter doping ratio normally used in HBT devices.

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

2005-05-01

7

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

NASA Astrophysics Data System (ADS)

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-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 1×1018 to 1×1020 cm-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 ~1.5×108 cm/s attain a cooler distribution with a mean velocity of ~4×107 cm/s within about 1 ps for p doping in excess of 1×1019 cm-3. The temporal evolution of average velocity of the electrons should be useful in obtaining values of the base width suitable for effective operation of HBTs.

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

2001-07-01

8

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

9

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

NASA Astrophysics Data System (ADS)

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

Vainshtein, Sergey; Kostamovaara, Juha

2006-04-01

10

Charge separation for bipolar transistors  

Microsoft Academic Search

The effect of net positive oxide trapped charge and surface recombination velocity on excess base current in BJTs (bipolar junction transistors) 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

S. L. Kosier; R. D. Schrimpf; R. N. Nowlin; D. M. Fleetwood; M. Delaus; R. L. Pease; W. E. Combs; A. Wei; F. Chai

1993-01-01

11

Thermal Design of Multifinger Bipolar Transistors  

Microsoft Academic Search

In this paper, design guidelines are provided to improve the thermal stability of three- and four-finger bipolar transistors. Experiments and simulations are first performed on silicon-on-glass (SOG) three-finger bipolar junction transistors (BJTs) with self-heating and mutual thermal resistances varying in a large range of values, depending on the silicon area, presence of heat spreaders, isolation, and distance between fingers. To

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

2010-01-01

12

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

NASA Technical Reports Server (NTRS)

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

Black, J. M. (inventor)

1979-01-01

13

Magnetoamplification in a bipolar magnetic junction transistor.  

PubMed

We have demonstrated the first bipolar magnetic junction transistor using a dilute magnetic semiconductor. For an InMnAs p-n-p transistor magnetoamplification is observed at room temperature. The observed magnetoamplification is attributed to the magnetoresistance of the magnetic semiconductor InMnAs heterojunction. The magnetic field dependence of the transistor characteristics confirm that the magnetoamplification results from the junction magnetoresistance. To describe the experimentally observed transistor characteristics, we propose a modified Ebers-Moll model that includes a series magnetoresistance attributed to spin-selective conduction. The capability of magnetic field control of the amplification in an all-semiconductor transistor at room temperature potentially enables the creation of new computer logic architecture where the spin of the carriers is utilized. PMID:20867602

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

2010-09-10

14

Heterostructure bipolar transistors and integrated circuits  

Microsoft Academic Search

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

HERBERT KROEMER

1982-01-01

15

Radiation Damage In Advanced Bipolar Transistors  

NASA Technical Reports Server (NTRS)

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

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

1989-01-01

16

Surface treatment for enhancing current gain of AlGaAs\\/GaAs heterojunction bipolar transistor  

Microsoft Academic Search

This paper presents a method of surface treatment for improving the current gain of an AlGaAs\\/GaAs heterojunction bipolar transistor (HBT). Several recipes for GaAs surface treatment, including each and several combinations of the H2 plasma, NH3 plasma, and (NH4)2Sx chemical treatments are examined. The lowest SiO2\\/GaAs interface state density of 1.23×1010 cm?2eV?1 is obtained when the GaAs surface is treated

T. K Oh; C. H Baek; B. K Kang

2004-01-01

17

Total Dose Effects in Conventional Bipolar Transistors  

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

18

A versatile, ion implanted bipolar transistor  

Microsoft Academic Search

This paper describes the physical properties of arsenic and boron implanted silicon which have enabled bipolar transistors with hFEfrom 20 to > 1000 and with fTfrom 1.5 GHz to 7.7 GHz to be made. The process, which is capable of producing extremely uniform distributions of electrical parameters (e.g., hFE112 ± 1.2) is clearly extendable to a broad distribution of possible

R. J. Scavuzzo; R. S. Payne; K. H. Olson; J. M. Nacci; R. A. Moline

1972-01-01

19

Fully ion-implanted bipolar transistors  

Microsoft Academic Search

Technology for the fabrication of fully ion-implanted bipolar transistors with arsenic emitters and boron bases is described. This technology results in extremely uniform distributions of electrical parameters, e.g,, hFE= 113 with a standard deviation of 1.3 across a wafer. In addition, it can produce a wide range of doping profiles and hence, a wide range of device performance. Using very

R. S. Payne; R. J. Scavuzzo; K. H. Olson; J. M. Nacci; R. A. Moline

1974-01-01

20

Photo carrier generation in bipolar transistors  

Microsoft Academic Search

Anomalous substrate currents have been observed in SiGe bipolar NPN-transistors, dependent on the collector bias, at high current levels. These currents appear to originate from light that is generated in the collector base junction when it is reverse biased. This light generates electron hole pairs in the n+ buried layer-substrate diode, yielding a considerable substrate current. This paper will show

Johan H. Klootwijk; Jan W. Slotboom; M. S. Peter; Victor Zieren; Dick B. de Mooy

2002-01-01

21

VBIC95: an improved bipolar transistor model  

Microsoft Academic Search

A new compact bipolar transistor model for circuit simulators that has already received widespread support in the industry, is considered. The model, VBIC95, was constructed to be the industry standard replacement for the aging SPICE Gummel-Poon model (SGP). Users of the 20-year-old SGP model have found it to be inadequate in representing, many of the physical effects important in modern

F. Najm

1996-01-01

22

Bipolar transistor equivalents in CMOS technology  

Microsoft Academic Search

A CMOS circuit element equivalent to a bipolar junction transistor (BJT) which provides symmetrical performances of npn\\/pnp and ideality factor programming is proposed. Simulation showed that the ?, and Early voltage are superior to those of a typical BJT below about 1.65 GHz in a 0.8 ?m CMOS technology and the fabricated prototype has 2.3×10-16 A of IS, 2.4 mA

Gyudong Kim; Min-Kyu Kim; Wonchan Kim; Abdesselam Bouzerdoum

1995-01-01

23

Bipolar Spintronics: From magnetic diodes to magnetic bipolar transistors  

NASA Astrophysics Data System (ADS)

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

Zutic, Igor

2004-03-01

24

Quantum-well-base heterojunction bipolar light-emitting transistor  

NASA Astrophysics Data System (ADS)

This letter reports the enhanced radiative recombination realized by incorporating InGaAs quantum wells in the base layer of light-emitting InGaP/GaAs heterojunction bipolar transistors (LETs) operating in the common-emitter configuration. Two 50 Å In1-xGaxAs (x=85%) quantum wells (QWs) acting, in effect, as electron capture centers (``traps'') are imbedded in the 300 Å GaAs base layer, thus improving (as a ``collector'' and recombination center) the light emission intensity compared to a similar LET structure without QWs in the base. Gigahertz operation of the QW LET with simultaneously amplified electrical output and an optical output with signal modulation is demonstrated.

Feng, M.; Holonyak, N.; Chan, R.

2004-03-01

25

Comparison of input offset voltage of differential amplifiers using bipolar transistors and field-effect transistors  

Microsoft Academic Search

A field-effect transistor (whether junction type or MOS type) has very high input impedance. For those who desire to achieve a higher input impedance, it is often asked `Why aren't FET pairs used as input stages and bipolar transistors used as output stages, since compatible FET and bipolar transistor monolithic structures have been developed?' This correspondence is a study of

H. C. Lin

1970-01-01

26

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.

27

Microwave multiple-state resonant tunneling bipolar transistors  

Microsoft Academic Search

Fabrication and microwave performance of a multiple-state resonant-tunneling bipolar transistor (RTBT) are presented. This transistor exhibits a maximum DC current gain of 60 at room temperature and a cutoff frequency of 24 GHz. Frequency multiplication by a factor of five has been demonstrated with a single transistor

L. M. Lunardi; S. Sen; F. Capasso; P. R. Smith; D. L. Sivco; A. Y. Cho

1989-01-01

28

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

29

Bounding the total-dose response of modern bipolar transistors  

SciTech Connect

The base current in modern bipolar transistors saturates at large total doses once a critical oxide charge is reached. The saturated value of base current is dose-rate independent. Testing implications are discussed.

Kosier, S.L.; Wei, A.; Schrimpf, R.D. [Arizona Univ., Tucson, AZ (United States). Dept. of Electrical and Computer Engineering; Combs, W.E. [Naval Surface Warfare Center-Crane, Crane, IN (United States); Fleetwood, D.M. [Sandia National Labs., Albuquerque, NM (United States); DeLaus, M. [Analog Devices, Inc., Wilmington, MA (United States); Pease, R.L. [RLP Research, Albuquerque, NM (United States)

1994-03-01

30

Emitter utilization in heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

We compare measured collector current densities, cutoff frequencies ( ft), and transducer gains for thermally shunted heterojunction bipolar transistors with 2-16 ?m emitter dot diameters or 2-8 ?m emitter bar widths with models of the emitter utilization factors. Models that do not take emitter resistance into account predict that the d.c. utilization factors are below 0.7 for collector current densities greater than 6 × 10 4 A cm -2 and emitter diameters or widths greater than 8 ?m. However, because the current gains are compressed by the emitter resistances at those current densities, the measured utilization factors are close to 1, which agrees with models that include emitter resistance. A.c. utilization factors are evident in the transistor Y parameters. For example, Re|Y 21z.sfnc drops off at high frequencies more steeply in HBTs with large emitter diameters or widths than in small ones. However, measured data shows that the HBT a.c. current gains h21 or ft values are not influenced by the a.c. utilization factor. A.c. utilization effects on HBT performance parameters such as small signal and power gains, output power, and power added efficiency are also examined.

Quach, T.; Jenkins, T.; Barrette, J.; Bozada, C.; Cerny, C.; Desalvo, G.; Dettmer, R.; Ebel, J.; Gillespie, J.; Havasy, C.; Ito, C.; Nakano, K.; Pettiford, C.; Sewell, J.; Via, D.; Anholt, R.

1997-09-01

31

Generation and recombination in two-dimensional bipolar transistors  

NASA Astrophysics Data System (ADS)

We study the effects of recombination and generation process on the operation of bipolar junction transistor based on two-dimensional materials, and in particular, graphone. Here, we use Shockley-Read-Hall model to study these process. First, we investigate the current-voltage characteristics of a graphone p- n junction considering generation and recombination process. Then, we calculate the estimated changes in current gain, cutoff frequency, and output characteristics of a graphone bipolar junction transistor designed in a recent study.

Gharekhanlou, Behnaz; Khorasani, Sina

2014-06-01

32

Low Frequency Noise in Strained Si Heterojunction Bipolar Transistors  

Microsoft Academic Search

The low frequency noise performance of strained Si heterojunction bipolar transistors (sSi HBTs) is presented for the first time. Conventional SiGe HBTs and Si bipolar junction transistors (BJTs), processed with strained Si devices, were also measured as a reference. It is found that a lower noise level is obtained in sSi HBTs for a given collector current, which is im-

M. Fjer; S. Persson; E. Escobedo-Cousin; A. G. O'Neill

2011-01-01

33

Single-event burnout of epitaxial bipolar transistors  

Microsoft Academic Search

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

S. Kuboyama; K. Sugimoto; S. Shugyo; S. Matsuda; T. Hirao

1998-01-01

34

Radiation effects on junction field-effect transistors (JFETS), MOSFETs, and bipolar transistors, as related to SSC circuit design.  

National Technical Information Service (NTIS)

Some results of radiation effects on selected junction field-effect transistors, MOS field-effect transistors, and bipolar junction transistors are presented. The evaluations include dc parameters, as well as capacitive variations and noise evaluations. T...

E. J. Kennedy G. T. Alley C. L. Britton P. L. Skubic B. Gray

1990-01-01

35

Free electron gas primary thermometer: The bipolar junction transistor  

NASA Astrophysics Data System (ADS)

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

Mimila-Arroyo, J.

2013-11-01

36

Heterojunction bipolar transistor technology for data acquisition and communication  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

37

Proton and gamma ray induced gain degradation in bipolar transistor  

NASA Astrophysics Data System (ADS)

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

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

2003-09-01

38

Thermal reliability of power insulated gate bipolar transistor (IGBT) modules  

Microsoft Academic Search

Thermal behavior of power insulated gate bipolar transistor (IGBT) modules was studied in this paper experimentally. Due primarily to the thermal mismatch in IGBT sandwich structure, thermal stress induced solder fatigue failures, such as the forming and growing of voids and cracks in IGBT solder layers, were quasi-dynamically observed in thermal cycling test. Thermal stress simulation provided stress distribution and

Wuchen Wu; Guo Gao; Limin Dong; Zhengyuan Wang; Marcel Held; Peter Jacob; Paolo Scacco

1996-01-01

39

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

40

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

41

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

42

Novel theory on the operation of bipolar junction transistor using internal photovoltaic effect model  

Microsoft Academic Search

Bipolar junction transistor (BJT) such as PNP or NPN transistor was invented by W.B. Shockley at the Bell Telephone Laboratories in 1948. And for more than sixty years since the birth of BJT, operation of bipolar junction transistor has been explained by the behaviors of electrons and positive holes in the emitter, base and collector regions which compose the BJT.

Kensho Okamoto

2011-01-01

43

Modeling of charge transport in ion bipolar junction transistors.  

PubMed

Spatiotemporal control of the complex chemical microenvironment is of great importance to many fields within life science. One way to facilitate such control is to construct delivery circuits, comprising arrays of dispensing outlets, for ions and charged biomolecules based on ionic transistors. This allows for addressability of ionic signals, which opens up for spatiotemporally controlled delivery in a highly complex manner. One class of ionic transistors, the ion bipolar junction transistors (IBJTs), is especially attractive for these applications because these transistors are functional at physiological conditions and have been employed to modulate the delivery of neurotransmitters to regulate signaling in neuronal cells. Further, the first integrated complementary ionic circuits were recently developed on the basis of these ionic transistors. However, a detailed understanding of the device physics of these transistors is still lacking and hampers further development of components and circuits. Here, we report on the modeling of IBJTs using Poisson's and Nernst-Planck equations and the finite element method. A two-dimensional model of the device is employed that successfully reproduces the main characteristics of the measurement data. On the basis of the detailed concentration and potential profiles provided by the model, the different modes of operation of the transistor are analyzed as well as the transitions between the different modes. The model correctly predicts the measured threshold voltage, which is explained in terms of membrane potentials. All in all, the results provide the basis for a detailed understanding of IBJT operation. This new knowledge is employed to discuss potential improvements of ion bipolar junction transistors in terms of miniaturization and device parameters. PMID:24854432

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

2014-06-17

44

Theory of electrothermal behavior of bipolar transistors: Part I -single-finger devices  

Microsoft Academic Search

A detailed theoretical and numerical analysis of the electrothermal behavior of single-finger bipolar transistors is proposed. Two models of different complexities are introduced to investigate self-heating effects in bipolar junction transistors (BJTs) and heterojunction bipolar transistors (HBTs) biased with a constant base-emitter voltage source or with a constant base current source. In the constant base-emitter voltage case, simple relations are

Vincenzo d'Alessandro

2005-01-01

45

Adjustable high-speed insulated gate bipolar transistor  

Microsoft Academic Search

A new adjustable insulated gate bipolar transistor (IGBT) with Si\\/SiGe heterojunction collector structures is proposed to improve the operation speed and decrease the turnoff power loss by suppressing the tail-current. SiGe collector provides low contact resistance without consequently sacrificing turnoff losses, and also acts to suppress hole-injection into drift region during on-state and accelerate the clear sweep of the holes

Fei Zhang; Lina Shi; Chengfang Li; Liang Zhang; Wei Wang; Wen Yu; Xiaowei Sun

2006-01-01

46

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

47

Geometry Considerations for Thermal Design of Microwave Heterojunction Bipolar Transistors  

Microsoft Academic Search

An efficient general algorithm for three-dimensional thermal simulation of semiconductor chips and its exemplary application to AlGaAs\\/GaAs heterojunction bipolar transistors (HBT) is presented. Firstly, the assumption of stationary heat sources as a boundary condition is validated by pulsed scattering parameter measurements. Secondly, the simulation method based on the fast Fourier transform is introduced. The model is verified by liquid crystal

Martin Kärner; Ulrich Schaper

1994-01-01

48

Doping To Reduce Base Resistances Of Bipolar Transistors  

NASA Technical Reports Server (NTRS)

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

Lin, True-Lon

1991-01-01

49

MEDICI Simulation of GaN Bipolar Junction Transistors  

Microsoft Academic Search

Previously, the basic operation principles of a homojunction GaN bipolar junction transistor (BJT) had been considered. Study of the governing theory for a BJT allowed for the design and optimization of a GaN BJT with respect to figures of merit characterizing DC, RF, high-power, and high-temperature performance. While the special features of nitrides present several formidable barriers to rapid development,

Michael Holub

50

Vertical NPN Bipolar Junction Transistors Fabricated in Silicon-on-Sapphire.  

National Technical Information Service (NTIS)

Previous attempts at fabricating vertical bipolar junction transistors (BJTs) on Silicon-on-Sapphire (SOS) have produced transistors with low Early voltages, high leakage currents and low current gain. These problems were attributed high density of microt...

B. W. Offord E. N. Cartagena H. Walker

1991-01-01

51

A review of radiation effects in heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

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

Weaver, B. D.

2005-09-01

52

Minority carrier transport properties of GaInNAs heterojunction bipolar transistors with 2% nitrogen  

NASA Astrophysics Data System (ADS)

GaAs-based heterojunction bipolar transistors (HBTs) have a relatively large turn-on voltage of approximately 1.4 V that can only be decreased by reducing the band-gap energy of the base material. 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. We report the performance of NpN double heterojunction bipolar transistors fabricated on a GaAs substrate with a Ga0.89In0.11N0.02As0.98 base that has a band-gap energy (Eg) of 0.98 eV; this is achieved with a nitrogen composition of 2%. These devices have a turn-on voltage VBE that is 0.4 V lower than that of their GaAs-base counterparts. The peak incremental current gain HFE is 8. The current gain of nitrogen containing HBTs is degraded due to the complex change in transport properties of carriers through the GaInNAs base region. In this article, the transport properties of GaInNAs-base HBTs are investigated by temperature-dependent dc current-voltage characteristics, optical and high frequency small-signal electrical measurements. The characterization of these devices is important to understand the effect of nitrogen on the device performance.

Welty, Rebecca J.; Xin, Huoping; Tu, Charles W.; Asbeck, Peter M.

2004-01-01

53

Base and collector resistances in heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

In heterojunction bipolar transistors (HBTs), the reverse base currents flow from the outer base periphery to the collector. The reverse base and collector resistances are therefore dominated by contact resistance, which is inversely proportional to the outer base and inner collector periphery lengths which are larger than the emitter lengths when the base and collector electrodes surround the emitter element. These resistances can be extracted from reverse Gummel (current vs Vbc with Vbc = 0) and from measurements of output resistances at zero collector voltage sweeps. We compare models with measurements where the base and collector peripheries decrease with increasing emitter diameters.

Anholt, R.; Bozada, C.; Desalvo, G.; Dettmer, R.; Ebel, J.; Gillespie, J.; Jenkins, T.; Havasy, C.; Ito, C.; Nakano, K.; Pettiford, C.; Quach, T.; Sewell, J.; Via, D.

1997-11-01

54

High power density pulsed X-band heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

Abrupt junction Npn AlGaAs/GaAs heterojunction bipolar transistors giving 10 GHz output power density of 6.2 mW/sq microns (18.7 W per mm emitter length) are reported. Pulse length was 300 nS with 33 percent duty cycle. Associated gain and power-added efficiency were 5.0 dB and 46 percent, respectively. Associated peak power was 561 mW. Peak and average powers were measured as a function of pulse length at fixed duty cycle and found to increase sharply from CW values for pulse lengths less than 1000 nS.

Adlerstein, M. G.; Zaitlin, M. P.; Flynn, G.; Hoke, W.; Huang, J.

1991-01-01

55

Electron counting at room temperature in an avalanche bipolar transistor  

NASA Astrophysics Data System (ADS)

We report on real-time detection of single electrons inside a n-p-n bipolar junction transistor at room temperature. Single electrons injected through the base-emitter junction trigger with a high probability the avalanche breakdown of the strongly reverse-biased collector-base junction. The breakdown, rapidly stopped by an avalanche quenching circuit, produces a voltage pulse at the collector which corresponds to the detection of a single electron. Pulse rates corresponding to currents down to the attoampere range are measured with an integration time of about 10 s.

Lany, Marc; Boero, Giovanni; Popovic, Radivoje

2008-01-01

56

Hot-carrier-induced photovoltage in silicon bipolar junction transistors  

NASA Astrophysics Data System (ADS)

As bipolar junction transistors (BJTs) are scaled down, the current density increases and base pushout may happen. To prevent base widening, the collector doping concentration is increased; therefore, this increases the electric field in the base-collector junction. In the active operation of BJTs, impact ionization happens and impact-ionization-induced photon emission is created in the base-collector (BC) junction and photon absorption happens in the base-emitter (BE) junction. This makes the carrier injection from the BE junction to the BC junction with avalanche different from that without avalanche. Similarly, the avalanche-induced light emission in the BE junction will induce photocarriers in the BC junction diode. In this paper, we report observation of the photovoltage in the BC junction resulting from hot-carrier electroluminence in the BE junction on a conventional low-power n- p- n bipolar transistor. We found a photovoltage of 0.36 V and a collector current reversal in the inverse active operation.

Jang, Sheng-Lyang; Chern, Kuang-Lang

1991-12-01

57

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

58

Noise behavior of GaAs field-effect transistors with short gate lengths  

Microsoft Academic Search

The noise behavior of the GaAs Schottky-barrier gate field-effect transistor has been investigated theoretically and experimentally. It has been found that an additional noise source has to be taken into account in GaAs FET's biased in the pinchoff region: the intervalley scattering noise. This noise source has been investigated and a new transistor noise model is proposed. Measured and calculated

W. Baechtold; W. V. Munch; N. Kawamura; D. Shinoda; R. Igarashi; H. Muta; Y. Seki

1972-01-01

59

Reduction in Turn-on Voltage in GaInNAs and InGaAs-Based Double-Heterojunction Bipolar Transistors  

NASA Astrophysics Data System (ADS)

A new quaternary material of GaInNAs has been proposed as base material for GaAs-based double-heterojunction bipolar transistors (DHBTs). The used InGaAs as base material results in the lower band gap energy of the base layer in heterojunction bipolar transistors (HBTs) followed by a smaller turn-on voltage. However, the compressive strain induced by the InGaAs grown on GaAs diminishes the influence of indium-addition induced band gap energy reduction, and thus abate turn-on voltage reduction. By incorporating suitable amounts of indium (In) and nitrogen (N) into GaAs, a smaller band gap material of GaInNAs lattice-matched to GaAs substrate can be obtained. In this study, N-p-n InGaP/Ga0.985In0.015N0.005As0.995/GaAs DHBTs have been demonstrated. A turn-on voltage reduction of 215 mV compared to that of the conventional HBT with a GaAs base layer was obtained. The device has a peak current gain of 85 and shows good high-frequency characteristics of fT and fMAX, which are both higher than 40 GHz

Wu, Cheng-Hsien; Su, Yan-Kuin; Wei, Shang-Chin; Chang, Shoou-Jinn; Sio, Chi-Cheong; Chen, Wei-Chang

2004-04-01

60

Optically controlled GaAs dual-gate MESFET and permeable base transistors  

NASA Technical Reports Server (NTRS)

Optically induced voltage and dc characteristics of the GaAs Dual-gate MESFET and the Permeable Base Transistor (PBT) with optical illumination at wavelength below 0.87 microns were obtained and compared with GaAs MESFET. It was observed that PBT can handle higher current density when illuminated.

Simons, R. N.; Bhasin, K. B.

1986-01-01

61

On DC modeling of the base resistance in bipolar transistors  

NASA Astrophysics Data System (ADS)

The total base resistance RB Tot constitutes a crucial parameter in modeling bipolar transistors. The significant physical effects determining RB Tot are current crowding and conductivity modulation in the base, both causing reduction of RB Tot with increasing base current IB. In this paper, it is shown that the reduction of RB Tot( IB) with increasing IB is directly related to the physical effect dominating in the base. A new model for RB Tot( IB) is presented where a parameter ? is introduced to account for the contributions of current crowding and conductivity modulation in the base. Theoretically, ? is equal to 0.5 when conductivity modulation is dominant and close to 1.0 when current crowding is the most significant effect. This was verified by measurements and simulations using a distributed transistor model which accounts for the lateral distribution of the base current and the stored base charge. The model proposed for RB Tot( IB) is very suitable for compact transistor modeling since it is given in a closed form expression handling both current crowding and conductivity modulation in the base. An accurate extraction procedure of the model parameters is also presented.

Linder, M.; Ingvarson, F.; Jeppson, K. O.; Grahn, J. V.; Zhang, S.-L.; Östling, M.

2000-08-01

62

Radiation effects on junction field-effect transistors (JFETS), MOSFETs, and bipolar transistors, as related to SSC circuit design  

SciTech Connect

Some results of radiation effects on selected junction field-effect transistors, MOS field-effect transistors, and bipolar junction transistors are presented. The evaluations include dc parameters, as well as capacitive variations and noise evaluations. The tests are made at the low current and voltage levels (in particular, at currents {le}1 mA) that are essential for the low-power regimes required by SSC circuitry. Detailed noise data are presented both before and after 5-Mrad (gamma) total-dose exposure. SPICE radiation models for three high-frequency bipolar processes are compared for a typical charge-sensitive preamplifier.

Kennedy, E.J. (Tennessee Univ., Knoxville, TN (USA) Oak Ridge National Lab., TN (USA)); Alley, G.T.; Britton, C.L. Jr. (Oak Ridge National Lab., TN (USA)); Skubic, P.L. (Oklahoma Univ., Norman, OK (USA)); Gray, B.; Wu, A. (Tennessee Univ., Knoxville, TN (USA))

1990-01-01

63

Thermal management of microwave power heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

A comprehensive study of the device layout effects on thermal resistance in thermally-shunted heterojunction bipolar transistors (HBTs) was completed. The thermal resistance scales linearly with emitter dot diameter for single element HBTs. For multiple emitter element devices, the thermal resistance scales with area. HBTs with dot geometrics have lower thermal impedance than bar HBTs with equivalent emitter area. The thermal resistance of a 200 ?m 2 emitter area device was reduced from 266°C/W to 146°C/W by increasing the shunt thickness from 3 ?m to 20 ?m and placing a thermal shunt landing between the fingers. Also, power-added efficiencies at 10 GHz were improved from 30% to 68% by this thermal resistance reduction.

Bozada, C.; Cerny, C.; De Salvo, G.; Dettmer, R.; Ebel, J.; Gillespie, J.; Havasy, C.; Jenkins, T.; Ito, C.; Nakano, K.; Pettiford, C.; Quach, T.; Sewell, J.; Via, G. D.; Anholt, R.

1997-10-01

64

Hydrodynamic transport models for an ultrathin base Si bipolar transistor  

NASA Astrophysics Data System (ADS)

Hydrodynamic models for carrier transport in semiconductors can be derived by taking moments of the Boltzmann transport equation. The maximum entropy principle allows us to obtain a closed hydrodynamic model, containing no free parameters, in order to describe transport phenomena under conditions very far from thermodynamic equilibrium. Under suitable scaling assumptions, the above model reduces to the energy transport model, to the Navier-Stokes-Fourier model, or to the drift diffusion one, in which all the transport coefficients are now explicitly determined. In this paper we study the applicability of these models to an ultrathin base npn silicon bipolar transistor where the transport is quasiballistic. The validity of the constitutive equations for the fluxes and the production terms (which are the moments over the collisional operator) is investigated by using Monte Carlo simulations.

Muscato, Orazio

2004-07-01

65

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

66

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

67

Bipolar Junction Transistors Fabricated in Silicon-On-Sapphire. (Reannouncement with New Availability Information).  

National Technical Information Service (NTIS)

The effects of processing temperature on collector leakage current in bipolar junction transistors (BJTs) fabricated in silicon-on-sapphire (SOS) were examined. At low process temperatures (850 deg C) a reduction of five orders of magnitude in the collect...

E. N. Cartagena B. Offord G. Garcia

1992-01-01

68

Neutron Hardness Assurance for Bipolar Transistors through Determination of Physical Parameters.  

National Technical Information Service (NTIS)

A nondestructive method of neutron radiation hardness assurance is developed for bipolar transistors using a detailed one-dimensional model to obtain the powers (sensitivity parameters) relating postirradiation h sub FE and V sub CE(sat) at any operating ...

R. D. Blice, J. A. Munarin

1975-01-01

69

Bipolar transport in organic field-effect transistors: organic semiconductor blends versus contact modification  

Microsoft Academic Search

The achievement of bipolar transport is an important feature of organic semiconductors, both for a fundamental understanding of transport properties and for applications such as complementary electronic devices. We have investigated two routes towards organic field-effect transistors exhibiting bipolar transport characteristics. As a first step, ambipolar field-effect transistors are realized by mixtures of p-conducting copper-phthalocyanine (CuPc) and n-conducting buckminsterfullerene (C60).

Andreas Opitz; Michael Kraus; Markus Bronner; Julia Wagner; Wolfgang Brütting

2008-01-01

70

Hybrid all-SiC MOS-gated bipolar transistor (MGT)  

Microsoft Academic Search

A MOS-gated bipolar transistor structure (called MGT), which consists of a MOSFET driving an npn bipolar junction transistor in a Darlington configuration, is experimentally demonstrated in SiC in hybrid form with a 6H-SiC lateral RESURF MOSFET driving high-voltage 4H-SiC implanted-emitter BJT. SiC MGT has several advantages over SiC IGBT, such as wider Safe Operation Area (SOA) as well as faster

Yi Tang; Sujit Banerjee; T. Paul Chow

2002-01-01

71

Radiation effects on bipolar junction transistors and integrated circuits produced by different energy Br ions  

Microsoft Academic Search

The radiation responses of the NPN bipolar junction transistors (BJTs) and the TTL bipolar integrated circuits (ICs) have been examined using 20, 40 and 60MeV Br ions. Key electric parameter was measured and compared after each energy irradiation. Experimental results demonstrate that the degradation in electric parameters caused by the Br ions shows a common feature for the NPN BJTs

Xingji Li; Hongbin Geng; Chaoming Liu; Zhiming Zhao; Mujie Lan; Dezhuang Yang; Shiyu He

2009-01-01

72

Total dose effects in conventional bipolar transistors and linear integrated circuits  

Microsoft Academic Search

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

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

1994-01-01

73

Lateral npn bipolar transistor for high current gain applications at reduced temperatures  

Microsoft Academic Search

The possibility of operating a high-current-gain lateral bipolar junction transistor (BJT), derived from a CMOS structure by jointing the gate and the substrate to form the base of the BJT, at very low temperature is described. This transistor does not suffer any current gain degradation at 77 K due to heavy doping effects. The structure can also be used in

J. C. S. Woo; S. Wong; S. Verdonckt-Vanderbroek; P. Ko; K. Terrill; P. K. Vasudev

1989-01-01

74

Impact of the back gate effect on bipolar junction transistors in smart power SOI technologies  

Microsoft Academic Search

This work investigates the effect of the back gate electrode on bipolar junction transistors (BJTs) in smart power SOI technologies. The impact on the BJT is discussed by means of measurements and device simulations. It is shown that proper back gate biasing results in a significant performance improvement for either the NPN or the PNP transistor. A design strategy is

Stefan Schwantes; Michael Graf; Volker Dudek

2005-01-01

75

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

76

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

77

Threshold Voltage Scattering of Ion Implanted GaAs Metal Semi-Conductor Field Effect Transistors  

Microsoft Academic Search

The Vth scattering of GaAs metal semi-conductor field effect transistors (MESFETs) by ion implantation process were evaluated. In the case of depletion-mode field effect transistors (D-FET) whose gate length (Lg) was 0.76 mum, the standard deviation of Vth average (< Vth>) for 147 wafers was 0.015 V and the average of the Vth standard deviation for each wafer (sigma Vth)

Yoshihiro Saito; Shigeru Nakajima

2003-01-01

78

InGaP/InGaAsN/GaAs NpN double heterojunction bipolar transistor  

SciTech Connect

The authors have demonstrated a functional NpN double heterojunction bipolar transistor (DHBT) using InGaAsN for 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 HBT. The lower V{sub ON} is attributed to the smaller bandgap (E{sub g}=1.20eV) of MOCVD 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 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 {triangle}E{sub C} 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 7 with ideal IV characteristics.

Chang, P.C.; Baca, A.G.; Li, N.Y.; Xie, X.M.; Sharps, P.R.; Hou, H.Q.

2000-01-10

79

Neutron Radiation Effect On 2N2222 And NTE 123 NPN Silicon Bipolar Junction Transistors  

NASA Astrophysics Data System (ADS)

This paper examines neutron radiation with PTS (Pneumatic Transfer System) effect on silicon NPN bipolar junction transistors (2N2222 and NTE 123) and analysis of the transistors in terms of electrical characterization such as current gain after neutron radiation. The key parameters are measured with Keithley 4200SCS. Experiment results show that the current gain degradation of the transistors is very sensitive to neutron radiation. The neutron radiation can cause displacement damage in the bulk layer of the transistor structure. The current degradation is believed to be governed by increasing recombination current between the base and emitter depletion region.

Oo, Myo Min; Rashid, N. K. A. Md; Karim, J. Abdul; Zin, M. R. Mohamed; Hasbullah, N. F.

2013-12-01

80

Comparative low frequency noise analysis of bipolar and MOS transistors using an advanced complementary BiCMOS technology  

Microsoft Academic Search

In this paper, for the first time we compare 1\\/f noise in both complementary bipolar and complementary MOSFET transistors fabricated on thick film bonded SOI with full dielectric isolation capability. For MOS devices, a new relationship for 1\\/f noise is given which allows intuitive insight when comparing technologies. Both bipolar and MOS transistors show agreement to a number fluctuation model

Jeffrey A. Babcock; Bill Loftin; Praful Madhani; Xinfen Chen; Angelo Pinto; Dieter K. Schroder

2001-01-01

81

Current gain rolloff in graded-base SiGe heterojunction bipolar transistors  

SciTech Connect

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

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

1993-04-01

82

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

83

A single electron bipolar avalanche transistor implemented in 90 nm CMOS  

NASA Astrophysics Data System (ADS)

A Single Electron Bipolar Avalanche Transistor (SEBAT) with attoampere sensitivity and ?10 Hz off-count rate is successfully integrated into 90 nm CMOS. The reported SEBAT has 120 dB (10 Hz-10 MHz) dynamic range corresponding to 0-0.35 VBE, and an IE ?10-18-10-12 A. Single-transistor ADC operation of the SEBAT is demonstrated by AC-coupling signals into the base.

Webster, Eric A. G.; Richardson, Justin A.; Grant, Lindsay A.; Henderson, Robert K.

2012-10-01

84

Low-frequency noise in UHV\\/CVD epitaxial Si and SiGe bipolar transistors  

Microsoft Academic Search

In this work a comprehensive investigation of low-frequency noise in ultrahigh vacuum\\/chemical vapor deposition (UHV\\/CVD) Si and SiGe bipolar transistors is presented. The magnitude of the noise of SiGe transistors is found to be comparable to the Si devices for the identical profile, geometry, and bias. A comparison with different technologies demonstrates that the SiGe devices have excellent noise properties

Lakshmi S. Vempati; John D. Cressler; Jeffrey A. Babcock; Richard C. Jaeger; David L. Harame

1996-01-01

85

A high current gain 4H-SiC NPN power bipolar junction transistor  

Microsoft Academic Search

This work reports the development of high power 4H-SiC bipolar junction transistors (BJTs) by using reduced implantation dose for p+ base contact region and annealing in nitric oxide of base-to-emitter junction passivation oxide for 2 hours at 1150°C. The transistor blocks larger than 480 V and conducts 2.1 A (Jc=239 A\\/cm2) at Vce=3.4 V, corresponding to a specific on-resistance (Rsp

Jianhui Zhang; Yanbin Luo; Petre Alexandrov; Leonid Fursin; Jian H. Zhao

2003-01-01

86

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

87

High gain optical detection with GaAs field effect transistors.  

PubMed

The photoresponse of GaAs field effect transistor (FET) optical detectors to optical intensity modulation signals of moderate frequency is investigated. High ac responsivity is available at frequencies of interest in optical communications: more than 6 A/W can be obtained up to 100 MHz, with a noise equivalent power of <10(-12) W/ radicalHz. The slope of the frequency response is dependent on the otpical bias power, an effect that can be attributed to traps. The GaAs FET optical detector complements the performance of available P-I-N and avalanche photodiode photodetectors for communications by providing high photoresponse at low bias voltages. PMID:20309161

Macdonald, R I

1981-02-15

88

Total Dose and Dose Rate Models for Bipolar Transistors in Circuit Simulation.  

National Technical Information Service (NTIS)

The objective of this work is to develop a model for total dose effects in bipolar junction transistors for use in circuit simulation. The components of the model are an electrical model of device performance that includes the effects of trapped charge on...

P. M. Campbell S. D. Wix

2013-01-01

89

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

SciTech Connect

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 exits between the measured and the simulated results.

Keshavarz, A.A. [Alliance Technologies, Inc., Albuquerque, NM (United States); Raney, C.W.; Campbell, D.C. [Sandia National Labs., Albuquerque, NM (United States)

1993-08-01

90

A charge sensitive preamplifier made with SiGe bipolar transistors  

Microsoft Academic Search

We have characterized some commercial SiGe bipolar transistors to be used at low injection level and in a wide temperature range, in view of their possible application in experiments with large number of channels. After having observed that they are very suitable for low noise and high-speed applications we have designed and built a charge sensitive preamplifier able to work

Claudio Arnaboldi; Giuliano Boella; Gianluigi Pessina

2004-01-01

91

Characterization of light emission from SiGe heterojunction bipolar transistor for photon emission microscopy applications  

Microsoft Academic Search

Light emission from SiGe heterojunction bipolar transistors (HBTs) was characterized for photon emission microscopy applications. Radiative recombination dominates in the non-saturation regime. It increases in the saturation regime due to an increased concentration of minority charge carriers in the base. Hot electron radiation dominates in the avalanche and is suppressed at large collector currents due to base widening.

Stas Polonsky; Andrei Talalaevskii; Moyra McManus

2003-01-01

92

Diffused planar InP bipolar transistor with a cadmium oxide film emitter  

Microsoft Academic Search

A novel bipolar InP transistor is demonstrated which comprises a Zn-diffused base and a transparent conductor widegap emitter made of sputtered cadmium oxide. Preliminary current gain was about 10. Owing to its less demanding planar technology the device is assessed to be promising for monolithic integration.

L. M. Su; N. Grote; F. Schmitt

1984-01-01

93

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

94

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

Microsoft Academic Search

In this paper we report the results of extensive research on phase modulation (PM) and amplitude modulation (AM) noise in linear bipolar junction transistor (BJT) amplifiers. BJT amplifiers exhibit 1\\/f PM and AM noise about a carrier signal that is much larger than the amplifiers thermal noise at those frequencies in the absence of the carrier signal. Our work shows

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

1997-01-01

95

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

96

Anode Engineering for the Insulated Gate Bipolar Transistor—A Comparative Review  

Microsoft Academic Search

Significant effort has been placed in anode engineering for the insulated gate bipolar transistor (IGBT) as a method to enhance the on-state\\/switching loss tradeoff. For the first time, we have taken a comprehensive selection of these designs and individually implemented them all into a 1200 V vertical structure. It is shown that all passive anode engineering structures lie on or

David W. Green; Konstantin V. Vershinin; Mark Sweet; Ekkanath Madathil Sankara Narayanan

2007-01-01

97

The Influence on Electrical Performance of Double-Polysilicon Bipolar Transistors by Forming Gas Annealing  

Microsoft Academic Search

The influence on the electrical performance of double-polysilicon self-aligned bipolar junction transistors by hydrogen passivation using forming gas annealing (FGA) was investigated. While the collector current remained essentially unaffected, the base current decreased substantially after the FGA. As a result, the peak DC current gain increased approximately by a factor of three. A simple model was employed to extract the

M. Sandén; T. E. Karlin; P. Ma; J. V. Grahn; S.-L. Zhang; M. Östling

1999-01-01

98

SiGe-base heterojunction bipolar transistors: physics and design issues  

Microsoft Academic Search

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

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

1990-01-01

99

Emitter injection efficiency and base transport factor in InAs bipolar transistors  

Microsoft Academic Search

The factors affecting the common emitter current gain (?) in InAs bipolar junction transistors (BJTs) have been studied by estimating the base transport factor (?T) and the emitter injection efficiency (?). This has been accomplished by employing a specially designed sequence of InAs npn BJTs. ?T, ?, and the minority carrier (electrons) diffusion length in the base (LB) are extracted

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

2003-01-01

100

Modelling of NPN Bipolar Junction Transistor Characteristics Using Gummel Plot Technique  

Microsoft Academic Search

In this paper, electrical characteristics of bipolar junction transistor (BJT) are studied by using Gummel plot focusing on gain. The investigation has been carried out by using SILVACO Software tool, 6 cases of different doping concentration for base and emitter have been carried out to determine the best concentration that will produce large gain. It can be conclude that emitter

A. S. Zoolfakar; N. A. Shahrol

2010-01-01

101

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

102

Collapse and large signal modelling of GaAs field effect transistors at 77 K  

Microsoft Academic Search

A complete electrical characterization of different types of GaAs field effect transistors at liquid nitrogen temperature is performed. The trapping-detrapping mechanisms on deep levels are particularly adressed and a method is proposed to circumvent the collapse phenomenom which otherwise limits the electrical performances. From these measurements a HEMT non-linear model is extracted and is found efficient for the prediction of

J. Verdier; J. M. Dienot; R. Plana; Ph. Andre; J. Graffeuil

1994-01-01

103

Lateral PNP bipolar transistor with aiding field diffusions  

NASA Technical Reports Server (NTRS)

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

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

1969-01-01

104

Extended base H+-ion sensitive bipolar junction transistor with SnO2\\/ITO glass sensing membrane  

Microsoft Academic Search

In this study, an extended base bipolar junction transistor (EBBJT) as an H+ ion sensitive device have been investigated. The SnO2\\/ITO glass, fabricated by sputtering SnO2 on the conductive ITO glass, is used as a pH-sensitive membrane for electrode, which is connected with a commercial bipolar junction transistor (BJT) device. The experimental data show that this structure has a linear

Chung-Yuan Chen; Hsiu-Li Hsieh; Tai-Ping Sun; Congo Tak-Shing Ching; Po-Liang Liu

2009-01-01

105

Non-uniform bipolar conduction in single finger NMOS transistors and implications for deep submicron ESD design  

Microsoft Academic Search

This paper presents a detailed study of the nonuniform bipolar conduction phenomenon in single finger NMOS transistors and analyses its implications for deep submicron ESD design. It is shown that the uniformity of lateral bipolar triggering is severely degraded with device width (W) in advanced technologies with silicided diffusions and low resistance substrates, and that this effect can only be

Kwang-Hoon Oh; Charvaka Duvvury; Craig Salling; Kaustav Banerjee; Robert W. Dutton

2001-01-01

106

Bias Dependence of Intermodulation Distortion Asymmetry in Heterojunction Bipolar Transistor Using Nonlinear Large-Signal Model  

Microsoft Academic Search

The asymmetry between lower and upper intermodulation distortions (IMD) in a heterojunction bipolar transistor (HBT), which can be observed under certain baseband termination and bias conditions, is analyzed using a large-signal model. This approach enables harmonic balance analysis of IMD asymmetry in nonlinear circuits using HBTs and, therefore, overcomes the limitations of the conventional Volterra-series analysis. Closed-form expression derived from

Hyun-Min Park; Songcheol Hong

2003-01-01

107

Low-frequency noise in TFSOI lateral n-p-n bipolar transistors  

Microsoft Academic Search

Low-frequency (1\\/f) noise is characterized as a function of base current density (JB) on thin-film-silicon-on-insulator (TFSOI) lateral bipolar transistors. In the low injection region of operation, the noise power spectral density was proportional to JB 1.8 for JB<0.4 ?A\\/?m2, which suggest that the noise in these devices is primarily dominated by a uniform distribution of noise sources across the emitter-base

Jeffrey A. Babcock; Dieter K. Schroder; Wen-Ling Margaret Huang; Jenny M. Ford

2001-01-01

108

Modeling of Bipolar Junction Transistor in FDTD Simulation of PrintedCircuit Board  

Microsoft Academic Search

Abstract—A simple and ecient,approximate method to incorporate nonlinear bipolar junction transistor (BJT) into Finite-Dierence Time-Domain (FDTD) framework is presented. This method applies Taylor expansion on the nonlinear transport equations of the BJT based on Gummel-Poon model,[5]. The results are two coupled one-step explicit finite dierence,schemes for the electromagnetic fields in the vicinity of the BJT, which can be solved easily.

F. Kung; H. T. Chuah

2002-01-01

109

A new synchronous rectifier using bipolar transistor driven by current transformer  

Microsoft Academic Search

A new synchronous rectifier (SR) unit is proposed. SR has low offset voltage, which improves the efficiency oflow-voltage power supplies. The SR consists of a bipolar junction transistor (BJT) with a low on-resistance and a current transformer (CT). It is turned on by the free-wheeling current due to positive feedback through the CT. This unit needs no extra drive-circuit for

E. Sakai; K. Harada

1992-01-01

110

A charge sensitive preamplifier made with SiGe bipolar transistors  

NASA Astrophysics Data System (ADS)

We have characterized some commercial SiGe bipolar transistors to be used at low injection level and in a wide temperature range, in view of their possible application in experiments with large number of channels. After having observed that they are very suitable for low noise and high-speed applications we have designed and built a charge sensitive preamplifier able to work at tens of nsec shaping time. In this paper, the preamplifier performances at room temperature are described.

Arnaboldi, Claudio; Boella, Giuliano; Pessina, Gianluigi

2004-02-01

111

Measurements of Avalanche Effects and Light Emission in Advanced Si and SiGe Bipolar Transistors  

Microsoft Academic Search

In this paper we present the first measurements of the light emitted by advanced npn bipolar transistors in the 1.1 - 2.7 eV energy range. Light emitted by recombination in the forward biased BE junction dominates the spectra in the low-energy, 1.1 - 1.3 eV region, while hot-electron-induced light emission in the collector region dominates for photon energies above 1.5

Enrico Zanoni; Stefano Bigliardi; Paolo Pavan; Pietro Pisoni; Claudio Canali

1991-01-01

112

Improvement of the Safe Operating Area for P-Channel Insulated-Gate Bipolar Transistors (IGBTs)  

Microsoft Academic Search

A p-channel insulated-gate bipolar transistor (IGBT), which is supposed to be useful for many applications especially for inverters, is developed. The SOA (safe operating area) of p-channel IGBTs is narrower than that of n-channel IGBTs because of the positive-feedback mechanism between a high rate of the avalanche multiplication of electrons and a high current gain hfe of the wide-base npn

Katsunori Ueno; Yasuyuki Hoshi; Noriyuki Iwamuro; Naoki Kumagai; Osamu Hashimoto

1991-01-01

113

High-low polysilicon-emitter SiGe-base bipolar transistors  

Microsoft Academic Search

Self-aligned heterojunction bipolar transistors with a high-low emitter profile consisting of a heavily doped polysilicon contact on top of a thin epitaxial emitter cap have been fabricated. The low doping in the single-crystal emitter cap allows a very high dopant concentration in the base with low emitter-base reverse leakage and low emitter-base capacitance. The thin emitter cap is contacted by

E. F. Crabbe; James H. Comfort; John D. Cressler; J. Y.-C. Sun; J. M. C. Stork

1993-01-01

114

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

115

Hydrodynamic Modeling of an Ultra-Thin Base Silicon Bipolar Transistor  

Microsoft Academic Search

Transport phenomena in a submicron npn silicon bipolar junction transistor are described by using an extended hydrodynamic model for the electrons, combined with a solution of the drift-diffusion model for the holes. Under suitable scaling assumptions, the above model reduces to the energy transport model, or to the Navier-Stokes-Fourier model, in which all the transport coefficients are now explicitly determined.

O. Muscato

116

The effect of parasitic bipolar transistor on the performance and reliability of scaled vertical power DMOSFETs  

Microsoft Academic Search

The parasitic bipolar transistor inherent in the silicided vertical double diffused MOSFET (DMOSFET) can greatly affect its performance and reliability. Scaled low-voltage power DMOSFETs with TiSi 2 source contacts were reported and anomalous “kinks” in the output I-V characteristics were observed. It was shown that a high contact resistance of TiSi2 contacts to the p-body diffusion caused the high output

K. Fischer; K. Shenai

1995-01-01

117

Low temperature operation of Si and SiGe bipolar transistors  

Microsoft Academic Search

The operation of Si and SiGe epitaxial-base bipolar transistors at liquid nitrogen temperature is demonstrated to be comparable or superior to that at room temperature. Tunneling leakage at the emitter-base junction is suppressed at all temperatures as a result of a lightly doped spacer. The maximum current gain of both the Si and the SiGe devices shows a very small

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

1990-01-01

118

1800 V NPN bipolar junction transistors in 4H-SiC  

Microsoft Academic Search

The first high voltage npn bipolar junction transistors (BJTs) in 4H-SiC have been demonstrated. The BJTs were able to block 1800 V in common emitter mode and showed a peak current gain of 20 and an on-resistance of 10.8 m?·cm2 at room temperature (IC=2.7 A @ VCE=2 V for a 1 mm×1.4 mm active area), which outperforms all SiC power

Sei-Hyung Ryu; Anant K. Agarwal; Ranbir Singh; John W. Palmour

2001-01-01

119

Mechanisms leading to erratic snapback behavior in bipolar junction transistors with base emitter shorted  

Microsoft Academic Search

This paper discusses two different modes of breakdown in the reverse-biased I-V characteristics observed generically in bipolar junction transistors (BJTs) with the base emitter shorted, showing an erratic behavior, in the presence of large displacement currents. Experimental observations related to reverse-biased collector junctions of BJTs, that exhibit two different states of breakdown when a fast voltage ramp is applied are

Amitabh Chatterjee; Ronald D. Schrimpf; Sameer Pendharkar; Kaustav Banerjee

2005-01-01

120

Radiation effects on bipolar junction transistors induced by 25 MeV carbon ions  

Microsoft Academic Search

The characteristic degradation in silicon NPN bipolar junction transistors (BJTs) of 3DG112 type is examined under the irradiation with 25MeV carbon (C) ions and various bias conditions. Different electrical parameters were measured in-situ during the exposure under each bias condition. From the experimental data, larger variation of base current (IB) is observed after irradiation at a given value of base-emitter

Chaoming Liu; Xingji Li; Hongbin Geng; Zhiming Zhao; Dezhuang Yang; Shiyu He

2010-01-01

121

Current status and future prospects of 4H-SiC power RF bipolar junction transistors  

Microsoft Academic Search

This paper reviews the current status of 4H-SiC RF NPN bipolar junction transistors (BJT's). Process developments including precise and uniform SiC etch and low resistance p-type ohmic contact formation on a two inch SiC wafer will be presented. The high temperature operation up to 500degC and radiation hardness up to 1.6 Mrad, as well as RF performance promising for long-pulse

Feng Zhao

2009-01-01

122

4 kV 4H-SiC epitaxial emitter bipolar junction transistors  

Microsoft Academic Search

In this paper, we present 4H-SiC bipolar junction transistors (BJTs) with open-base blocking voltage (BVCEO) of 4000 V, specific on-resistance (Ron,sp) of 56 m?-cm2, and common-emitter current gain ??9. These devices are designed with interdigitated base and emitter fingers with multiple emitter stripes. We assess the impact of design (emitter stripe width and contact spacing) on device performance and also

Santhosh Balachandran; T. P. Chow; A. Agarwal; C. Scozzie; K. A. Jones

2005-01-01

123

Effect of avalanche-induced light emission on the multiplication factor in bipolar junction transistors  

NASA Astrophysics Data System (ADS)

In Si bipolar junction transistors, the base and collector currents, including avalanche effects, are often modeled without accounting for the avalanche-induced light emission. The light absorption and light-induced carrier injection into the avalanche region were therefore neglected. In this paper, we formulate the multiplication factor so as to account for the avalanche-induced carrier injection into the breakdown region and we discuss the mechanism neglected earlier.

Sheng-Lyang Jang

1991-11-01

124

Hot-carrier induced degradation and recovery in polysilicon-emitter bipolar transistors  

Microsoft Academic Search

We have studied in detail the hot-carrier induced degradation in polysilicon-emitter NPN bipolar junction transistors (BJTs) with different emitter geometries. Our results confirm that the oxide\\/silicon interface traps generated by electrical stressing, are located in the same region as those present in unstressed devices - around the emitter perimeter. We also believe that positive charged defects are generated by the

S. R. Sheng; S. P. McAlister; L.-S. Lee; H. P. Hwang

2001-01-01

125

Avalanche multiplication in forward- and reverse-active mode bipolar junction transistors  

Microsoft Academic Search

Impact ionization in the reverse-biased base-collector space-charge layer of the bipolar junction transistor (BJT) can cause an avalanche collector current as well as a reverse (or negative) base current. We develop analytical models to predict and compare avalanche phenomena in the BJT biased under forward-active and under reverse-active operations. The models consider a position-dependent electric field in the space-charge layer,

J. J. LIOU

1993-01-01

126

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

Microsoft Academic Search

The characteristic degradations in a silicon NPN bipolar junction transistor (BJT) of 3DG142 type are examined under irradiation with 40-MeV chlorine (Cl) ions under forward, grounded, and reverse bias conditions, respectively. Different electrical parameters are in-situ measured during the exposure under each bias condition. From the experimental data, a larger variation of base current (IB) is observed after irradiation at

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

2012-01-01

127

Emitter injection efficiency and base transport factor in InAs bipolar transistors  

Microsoft Academic Search

The factors affecting the common emitter current gain (beta) in InAs bipolar junction transistors (BJTs) have been studied by estimating the base transport factor (alphaT) and the emitter injection efficiency (gamma). This has been accomplished by employing a specially designed sequence of InAs npn BJTs. alphaT, gamma, and the minority carrier (electrons) diffusion length in the base (LB) are extracted

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

2003-01-01

128

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

129

Emitter structure of power heterojunction bipolar transistor for enhancement of thermal stability  

Microsoft Academic Search

This paper proposes two methods for enhancing thermal stability of a multi-finger power heterojunction bipolar transistor (HBT). The methods adjust either the spacing or length of emitter fingers to improve thermal stability. The temperature rise at the device center of the space-adjusted HBT is suppressed by reducing heat flow from adjacent fingers, and that of the length-adjusted HBT is suppressed

J. G. Lee; T. K. Oh; B. Kim; B. K. Kang

2001-01-01

130

Nondestructive characterization of RBSOA of high-power bipolar transistors  

NASA Astrophysics Data System (ADS)

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

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

1986-03-01

131

Surface passivation of InP/InGaAs heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

The effect of different dielectric films deposited by different techniques, on the electrical characteristics of InP/InGaAs heterojunction bipolar transistors was investigated. The electrical characteristics vary significantly depending on the type of dielectric film used for passivation. A significant increase in the forward biased base current, which resulted in lower transistor gain as well as an increased reverse leakage current in the base-collector junction, was observed when silicon nitride and silicon dioxide were deposited using plasma enhanced chemical vapour deposition. On the other hand, silicon monoxide and strontium fluoride films deposited using thermal evaporation, resulted in little degradation in the transistor characteristics. The low-temperature deposition was believed to have induced less surface states, resulting in the electrical characteristics being maintained long after deposition.

Ng, W. K.; Tan, C. H.; Houston, P. A.; Krysa, A.; Tahraoui, A.

2004-06-01

132

Sulfur passivation of GaAs metal-semiconductor field-effect transistor  

NASA Astrophysics Data System (ADS)

A passivation technique consisting of a (NH4)2S dip followed by GaS deposition has been applied to a GaAs microwave-power metal-semiconductor field-effect transistor (MESFET). The breakdown characteristic of the MESFET is greatly improved upon the (NH4)2S treatment, and a stable passivation effect can be achieved by GaS film deposition. It is found that the FET current-voltage characteristics are closely related to variations in the pinning position of the GaAs surface Fermi level. With the surface passivated, a depletion layer can be properly formed and protected, which is of benefit to the control of the device parameters.

Dong, Y.; Ding, X. M.; Hou, X. Y.; Li, Y.; Li, X. B.

2000-12-01

133

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

134

Energy dependence of proton displacement damage factors for bipolar transistors  

NASA Astrophysics Data System (ADS)

Displacement damage factors, K(p), have been measured as a function of collector current for proton irradiations of 2N2222A (npn) and 2N2907A (pnp) switching transistors and 2N3055 (npn) power transistors over the energy range 5.0 to 60.3 MeV. The measurements of K(p) were made on specially selected lots of devices and were compared to values of the neutron damage factors, K(n), for 1-MeV displacement damage equivalent neutrons made on the same devices. The results show that, so far as device operation is concerned, the nature of the displacement damage produced by high energy protons and by fission neutrons is essentially the same. Over the energy range studied, protons were found to be more damaging than neutrons. For 5.0 MeV protons Kp/Kn was about 8.5 compared to about 1.8 for 60.3 MeV protons.

Summers, Geoffrey P.; Xapsos, Michael A.; Dale, Cheryl J.; Wolicki, Eligius A.; Marshall, Paul

1986-12-01

135

Control of Zn diffusion in InP/InAlGaAs-based heterojunction bipolar transistors and light emitting transistors  

NASA Astrophysics Data System (ADS)

Zn diffusion behavior in InP/InAlGaAs heterojunction bipolar transistors and light emitting transistors grown by metalorganic chemical vapor deposition was investigated. Using secondary ion mass spectrometry, the Zn doping profiles in the epitaxial structures were studied in relation to their growth conditions. Migration of Zn atoms from the base layer was found to be a combined result of three mechanisms, i.e. the generation of excess group III interstitials during the n-type InP subcollector growth, the generation of Zn interstitials in the Zn-doped InAlGaAs base, and the presence of strong electric field at the emitter-base n-p junction. By choosing the growth conditions either to suppress or to enhance the effects of each mechanism, Zn is able to diffuse either in both directions into the adjacent emitter and collector, or forward only into the emitter, or backward only into the collector. An abrupt junction profile, with the suppression of Zn diffusion, in the InP:Si/In(Al 0.25Ga 0.75)As:Zn/InAlAs:ud/InP:Si light emitting transistor structure has been achieved by low Si doping in the InP subcollector, low temperature growth of the InAlGaAs base, and slightly high Si doping in the InP emitter.

Huang, Yong; Ryou, Jae-Hyun; Dupuis, Russell D.

2008-09-01

136

Dependence of burn-in effect on thermal annealing of the GaAs:C base layer in GaInP heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

We investigate in situ thermal annealing of the carbon-doped GaAs base layer in GaInP/GaAs heterojunction bipolar transistors grown by metalorganic chemical vapor deposition in order to eliminate hydrogen incorporation. The influence of the anneal on the carrier transport properties and on the burn-in effect is studied. Results show that the anneal reduces the burn-in effect due to an increase in the emitter minority carrier diffusion length which is caused by passivation of H+ recombination centers in the GaInP emitter layer. However, the anneal also degrades the base minority carrier diffusion length leading to a reduction in the current gain.

Mimila-Arroyo, J.; Cabrera, V.; Bland, S. W.

2003-04-01

137

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

Microsoft Academic Search

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

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

1997-01-01

138

Substrate Leakage Current in InGaP/GaAs Heterojunction Bipolar Transistors  

NASA Astrophysics Data System (ADS)

Substrate leakage current in InGaP/GaAs heterojunction bipolar transistors (HBTs) has been observed. For a substrate thickness of 100 ?m and an emitter area of 60 ?m2, the parasitic current is on the order of 10-8 A. The current flowing between the collector terminal and the substrate can be decomposed into linear and parabolic components. The parabolic dependence is also observed in Medici simulation. A theoretical derivation based on electron drift in the substrate shows parabolic dependence on applied voltage, consistent with our measurement and Medici simulation. In addition, it has been found that the current is inversely proportional to the cube of substrate thickness. To account for this substrate parasitic effect, a modification of the vertical bipolar inter-company (VBIC) model is proposed.

Chang, Yang-Hua; Chang, Zhi-Juan; Hsieh, Yi-Jing

2005-04-01

139

Investigation of thermal properties in fabricated 4H-SiC high power bipolar transistors  

NASA Astrophysics Data System (ADS)

Silicon carbide bipolar junction transistors have been fabricated and investigated. The transistors had a maximum current gain of approximately 10 times, and a breakdown voltage of 450 V. When operated at high power densities the device showed a clear self-heating effect, decreasing the current gain. The junction temperature was extracted during self-heating to approximately 150 °C, using the assumption that the current gain only depends on temperature. Thermal images of a device under operation were also recorded using an infrared camera, showing a significant temperature increase in the vicinity of the device. The device was also tested in a switched setup, showing fast turn on and turn off at 1 MHz and 300 V supply voltage. Device simulations have been used to analyze the measured data. The thermal conductivity is fitted against the self-heating, and the lifetime in the base is fitted against the measurement of the current gain.

Danielsson, E.; Zetterling, C.-M.; Domeij, M.; Östling, M.; Forsberg, U.; Janzén, E.

2003-04-01

140

The pulsed microwave damage trend of a bipolar transistor as a function of pulse parameters  

NASA Astrophysics Data System (ADS)

In the present paper we conduct a theoretical study of the thermal accumulation effect of a typical bipolar transistor caused by high power pulsed microwaves (HPMs), and investigate the thermal accumulation effect as a function of pulse repetition frequency (PRF) and duty cycle. A study of the damage mechanism of the device is carried out from the variation analysis of the distribution of the electric field and the current density. The result shows that the accumulation temperature increases with PRF increasing and the threshold for the transistor is about 2 kHz. The response of the peak temperature induced by the injected single pulses indicates that the falling time is much longer than the rising time. Adopting the fitting method, the relationship between the peak temperature and the time during the rising edge and that between the peak temperature and the time during the falling edge are obtained. Moreover, the accumulation temperature decreases with duty cycle increasing for a certain mean power.

Ma, Zhen-Yang; Chai, Chang-Chun; Ren, Xing-Rong; Yang, Yin-Tang; Zhao, Ying-Bo; Qiao, Li-Ping

2013-02-01

141

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

NASA Astrophysics Data System (ADS)

Insulated Gate Bipolar Transistor (IGBT) were applied in ultrasonic switching current source inverters for power purposes. The current source inverter is supplied by a current mode controlled chopper. Both parts, the inverter as well as the chopper consist of IGBT which enable the use of a 20 kHz switching frequency. The current source inverter is controlled by using a periodic switching pattern, generated by a partly free-programmable control systems consisting of a computer and a controllable external memory containing several tables of switching patterns. An output power of 4 kW is attained, demonstrating the applicability of IGBT in ultrasonic switching current source inverters for power purposes.

Blom, A. C.

1989-08-01

142

Minority carrier properties of carbon-doped GaInAsN bipolar transistors  

Microsoft Academic Search

We have developed an InGaP\\/GaInAsN\\/GaAs double heterojunction bipolar transistor technology that substantially improves upon existing GaAs-based HBTs. Band-gap engineering with dilute nitride GaInAsN alloys is utilized to enhance a variety of key device characteristics, including lower operating voltages, improved temperature stability and increased RF performance. Furthermore, GaInAsN-based HBTs are fully compatible with existing high-volume MOVPE and IC fabrication processes. While

R. E. Welser; R. S. Setzko; K. S. Stevens; E. M. Rehder; C. R. Lutz; D. S. Hill; P. J. Zampardi

2004-01-01

143

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

144

Validation of an extended hydrodynamic model for a submicron npn bipolar junction transistor  

NASA Astrophysics Data System (ADS)

Transport phenomena in a submicron npn silicon bipolar junction transistor are described by using an 8-moment model for the electrons, combined with a solution of the drift-diffusion model for the holes. The validity of the constitutive equations for the fluxes and the production terms, obtained by means of the maximum entropy principle, and the hyperbolicity conditions are checked with direct simulation Monte Carlo. We verify numerically that the quadratic closure is more accurate with respect to the zero-order one, but some irregularities can appear in the solution due to the loss of hyperbolicity in some regions of the device.

Muscato, Orazio

2006-06-01

145

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

SciTech Connect

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

Campbell, Phillip Montgomery; Wix, Steven D.

2013-05-01

146

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

PubMed

Broadband pulsed THz emission with peak power in the sub-mW range has been observed experimentally during avalanche switching in a gallium arsenide bipolar junction transistor at room temperature, while significantly higher total generated power is predicted in simulations. The emission is attributed to very fast oscillations in the conductivity current across the switching channels, which appear as a result of temporal evolution of the field domains generated in highly dense electron-hole plasma. This plasma is formed in turn by powerful impact ionization in multiple field domains of ultrahigh amplitude. PMID:17995354

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

2007-10-26

147

Breakdown characteristics of emitter-base and collector-base junctions of silicon bipolar junction transistors  

NASA Astrophysics Data System (ADS)

Recently, avalanche breakdown phenomena have received considerable attention. This is due to the lower breakdown voltage in advanced bipolar junction transistors (BJTs), which result from the increased collector doping. Avalanche breakdown in BJTs is an old issue; however, it is still not well-understood. This paper reports on studies of the breakdown characteristics of emitter-base and collector-base junctions with the other terminal open or shorted to the base. This is fundamental for the understanding of current-voltage characteristics of Si BJTs operated in the breakdown condition. The study includes the phenomena of avalanche breakdown, punchthrough and avalanche-induced light emission.

Jang, Sheng-Lyang; Chern, Kuang-Lang

1992-05-01

148

Terahertz Emission from Collapsing Field Domains during Switching of a Gallium Arsenide Bipolar Transistor  

NASA Astrophysics Data System (ADS)

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

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

2007-10-01

149

1/f noise in positive-negative-positive (PNP) polycrystalline silicon-emitter bipolar transistors  

NASA Astrophysics Data System (ADS)

The origin of 1/f fluctuations in positive-negative-positive (PNP) polycrystalline silicon-emitter bipolar-junction transistors is described. The interfacial oxide (IFO) at the monosilicon-polycrystalline silicon interface is found to significantly affect the noise behavior. The low-frequency noise originates from two independent fluctuation mechanisms: in the diffusion and tunneling components of the base current noise power spectral density (SIB) and from the diffusion current and carrier number fluctuations in the collector current noise power spectral density (SIC). The Hooge noise parameters for electrons and holes are calculated from the diffusion fluctuation models for SIB and SIC, respectively. Noise measurements on devices with different sizes and different IFO thicknesses indicate that the fluctuations occur in the minority-carrier (electron) tunneling current component of SIB through the IFO. The thickness of the IFO is estimated using this noise model. The tunneling fluctuations dominate over the diffusion fluctuations for the smaller (0.7×0.7 ?m2) transistors, while the opposite is the case for the larger (0.7×100 ?m2) ones. The scaling effect on the noise performance of these transistors is discussed. The effect of the IFO on the dc characteristics and the noise behavior of the PNP transistors is compared to that of the negative-positive-negative (NPN) counterparts on the same wafer.

Hoque, Md Mazhar Ul; Celik-Butler, Zeynep; Trogolo, Joe; Weiser, Douglas; Green, Keith

2005-04-01

150

Etude du transistor a grille isolee (IGBT) et de sa mise en serie. Application a un hacheur de 1500V-5A-10kHz. (Study of an Insulated Gate Bipolar Transistor (IGBT) and its connection in series. Application at a chopper 1500V-5A-10kHz).  

National Technical Information Service (NTIS)

In the frame of the tokamak ITER (International Thermonuclear Experimental Reactor) we have studied, for neutral particle injection, a converter with at least two static interrupters by Mosfet transistor, bipolar transistor or Insulated Gate Bipolar Trans...

P. Gros

1993-01-01

151

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

Microsoft Academic Search

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

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

1991-01-01

152

Low-frequency noise characteristics of UHV\\/CVD epitaxial Si and SiGe-base bipolar transistors  

Microsoft Academic Search

We report the first measurements of low-frequency noise in high-performance, UHV\\/CVD epitaxial Si- and SiGe-base bipolar transistors. The magnitude of the noise power spectral density at fixed frequency for both Si and SiGe devices is comparable for similar bias, geometry, and doping conditions, indicating that the use of strained SiGe alloys does not degrade transistor noise performance. The best recorded

John D. Cressler; Lakshmi Vempati; Jeffrey A. Babcock; Richard C. Jaeger; David L. Harame

1996-01-01

153

High-frequency performance limitations of millimeter-wave heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

Heterojunction bipolar transistor structures (HBTs) with 0.25-, 0.4-, and 0.6-micron emitter stripe widths and ultrasubmicrometer base widths, which are designed to achieve minimum transit time and low parasitic effects, are examined for their millimeter-wave performance. In particular, the dependence of the unity current gain frequency (f sub tau), the maximum oscillation frequency (f max), and the stability of power gains on the device structure and material parameters are critically analyzed. It is shown that the classical fmax expression commonly used for bipolar transistors, involving the effective carrier transit time and the collector-base RC time constant, does not adequately represent the performance of ultrasubmicrometer-base-width HBTs, where the transadmittance phase delay associated with the collector-base depletion layer transit time and the parasitic collector-base capacitance are significant. The expected ballistic and quasiballistic behavior of electrons in these ultrasubmicrometer structures, if properly designed, minimizes the effective carrier transit time effect, but its impact on the fmax by the excess transadmittance phase delay poses a more fundamental and serious high-frequency limiting factor for the realization of millimeter-wave HBTs than has been hitherto recognized. The accuracy and usefulness of the proposed analytical approach is demonstrated for a practical HBT structure with 1.2-micron emitter stripe design, giving results that agree well with measurements.

Das, Mukunda B.

1988-05-01

154

Optical reduction of low frequency noise in cryogenic GaAs junction field effect transistor  

NASA Astrophysics Data System (ADS)

We demonstrated optical low frequency noise reduction in a n-type SONY GaAs junction field effect transistor (JFET) (gate width: 5 ?m length: 1 ?m) operating at 4.2 K. At 1 Hz, a 6 dB decrease and a 10 dB increase in noise were observed when the JFET (band gap: 1.51 eV) was illuminated by light with wavelengths of 1650 and 1550 nm, respectively, for a drain voltage of 0.5 V and drain current of 0.25 ?A. When the drain current was 0.5 ?A, 1650 nm illumination increased the noise; moreover, hysteretic behavior in response to the illumination was also observed. These results show that deep level trapped charges apparently affect low frequency noise, which can be controlled by illumination using photons whose energies are below the band gap energy at cryogenic temperatures.

Fujiwara, M.; Nagata, H.; Matsuo, H.; Sasaki, M.

2008-07-01

155

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

SciTech Connect

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

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

2012-06-15

156

An analytical modeling approach for a gate all around (GAA) tunnel field effect transistor (TFET)  

NASA Astrophysics Data System (ADS)

An analytical model for a gate all around (GAA) Tunnel Field Effect Transistor (TFET) having circular and square cross section geometry has been proposed in this work describing the important device electrostatic parameters i.e. Surface Potential, Electric Field and Energy Band profile. Further, the model is extended for both a p-i-n and p-n-p-n architecture keeping in view the advantages offered by a p-n-p-n architecture (also known as tunnel source or halo doped TFET) over a p-i-n based TFET. The results obtained from the model have been validated with results obtained through Silvaco ATLAS 3D device simulation software.

Narang, Rakhi; Saxena, Manoj; Gupta, R. S.; Gupta, Mridula

2012-10-01

157

On the recombination currents effect of heterostructure-emitter bipolar transistors (HEBTs)  

NASA Astrophysics Data System (ADS)

In this paper, we will demonstrate the effect of recombination current on the electrical properties of heterostructure-emitter bipolar transistors (HEBTs). For comparison, an AlGaAs/GaAs and an AlInAs/GaInAs HEBT are fabricated with the same layer structure. The theoretical analysis shows that the neutral-emitter recombination current in the neutral emitter regime is a significant factor for determining transistor characteristics. For the AlGaAs/GaAs HEBT, the hole diffusion length is larger than the emitter thickness, so that most of holes can be reflected back at the confinement layer due to the hole recombination current being low in the neuter-emitter region. Thus, the high emitter injection efficiency and current gain can be achieved simultaneously. On the other hand, for the AlInAs/GaInAs HEBT, the increase of recombination current at neutral emitter regime and the existence of potential spike could reduce the emitter injection efficiency at large VBE voltage. Hence, the non-1KT component of collector current is enhanced and the characteristics of transistor are degraded. However, a lower offset voltage of 40 mV is obtained attributed to the low base surface recombination current for the AlInAs/GaInAs HEBT. All of these experimental results are consistent with the theoretical analysis.

Tsai, Jung-Hui; Laih, Lih-Wen; Shih, Hui-Jung; Liu, Wen-Chau; Lin, Hao-Hsiung

1996-12-01

158

Hot-carrier degradation in bipolar transistors at 300 and 110 K-effect on BiCMOS inverter performance  

Microsoft Academic Search

The degradation of bipolar transistors at 300 and 110 K under DC base-emitter reverse-bias stress is discussed. It is found that, for the same reverse voltage, the reverse current is about three to four times smaller at 100 than at 300 K, but the rate of base current degradation is several times larger. A method for modeling the degradation due

J. DAVID BURNETT; CHENMING HU

1990-01-01

159

Hot-Carrier Degradation and Oxide Charge Build-up in Self-Aligned Etched-Polysilicon npn Bipolar Transistors  

Microsoft Academic Search

The aim of this paper is to present the results of several accelerated tests performed on self-aligned bipolar transistors with emitter spacers. We show that the problem of lifetime extrapolation is complicated by a strong dependence of degradation kinetics on device layout. We also demonstrate, by means of emission microscopy, that remarkable current crowding effects take place during accelerated testing,

Andrea Neviani; Paolo Pavan; Tiziano Tommasin; Alessandra Nardi; Alain Chantre; Michele Stucchi; Loris Vendrame; Enrico Zanoni

1996-01-01

160

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

National Technical Information Service (NTIS)

This paper reports the first 4H-SiC power bipolar junction transistor (BJT) which is completely free of ion implantation and hence is free of the implantation-induced crystal damages and high-temperature activation annealing-induced surface roughness. The...

J. Zhang J. H. Zhao P. Alexandrov T. Burke X. Li

2007-01-01

161

The effect of hydrogen passivation on electrical characteristics of double-polysilicon self-aligned bipolar transistors  

Microsoft Academic Search

The influence of hydrogen passivation using forming gas annealing (FGA), on the electrical performance of double-polysilicon self-aligned bipolar junction transistors was investigated. While the collector current remained essentially unaffected after FGA, the base current decreased substantially. As a result, the peak DC current gain increased by a factor of three. Identification of the various base current components showed that the

M. Sandén; T. E Karlin; P Ma; J. V Grahn; S.-L Zhang; M Östling

1999-01-01

162

Collector-top GaAs/AlGaAs heterojunction bipolar transistors for high-speed digital ICs  

NASA Astrophysics Data System (ADS)

GaAs/AlGaAs collector-top heterojunction bipolar transistors with magnesium and phosphorus double-implanted external bases were fabricated. A cutoff frequency of 17 GHz and a gate delay time of 63 ps for DCTL were obtained. These results indicate the potential of collector-top HBTs for high-speed ICs.

Morizuka, K.; Nozu, T.; Tsuda, K.; Azuma, M.

1986-03-01

163

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

Microsoft Academic Search

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

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

1985-01-01

164

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

165

High-performance K-band GaAs power field-effect transistors prepared by molecular beam epitaxy  

NASA Technical Reports Server (NTRS)

The maturity of the molecular beam epitaxy (MBE) technique for preparing device quality GaAs material for microwave applications is demonstrated by the excellent performance characteristics of K-band GaAs power field-effect transistors (FETs) fabricated on the MBE wafers. An output power of 710 mW with 4.5-dB gain and 17.7 percent power-added efficiency was achieved at 21 GHz with a 1.26-mm gate width pi-gate device. A similar device with a 0.56-mm gate width produced an output power of 320 mW with 5.0-dB gain and 26.6 percent power-added efficiency at 21 GHz. These are the best results yet reported to date for GaAs power FETs operated in the K-band frequency range.

Saunier, P.; Shih, H. D.

1983-01-01

166

High-performance InGaP/GaAs pnp {delta}-doped heterojunction bipolar transistor  

SciTech Connect

In this article, a novel InGaP/GaAs pnp {delta}-doped heterojunction bipolar transistor is first demonstrated. Though the valence band discontinuity at InGaP/GaAs heterojunction is relatively large, the addition of a {delta}-doped sheet between two spacer layers at the emitter-base (E-B) junction effectively eliminates the potential spike and increases the confined barrier for electrons, simultaneously. Experimentally, a high current gain of 25 and a relatively low E-B offset voltage of 60 mV are achieved. The offset voltage is much smaller than the conventional InGaP/GaAs pnp HBT. The proposed device could be used for linear amplifiers and low-power complementary integrated circuit applications.

Tsai, J.-H. [National Kaohsiung Normal University, Department of Electronic Engineering (China)], E-mail: jhtsai@nknucc.nknu.edu.tw; Chiu, S.-Y.; Lour, W.-S. [National Taiwan Ocean University, Department of Electrical Engineering (China); Guo, D.-F. [Air Force Academy, Department of Electronic Engineering (China)

2009-07-15

167

SiGe:C Heterojunction Bipolar Transistors: From Materials Research to Chip Fabrication  

NASA Astrophysics Data System (ADS)

Incorporation of substitutional carbon ( ~10^20 cm^-3) into the SiGe region of a heterojunction bipolar transistor (HBT) strongly reduces boron diffusion during device processing. We describe the physical mechanism behind the suppression of B diffusion in C-rich Si and SiGe, and explain how the increased thermal stability of doping profiles in SiGe:C HBTs can be used to improve device performance. Manufacturability of SiGe:C HBTs with transit frequencies of 100 GHz and maximum oscillation frequencies of 130 GHz is demonstrated in a BiCMOS technology capable of fabricating integrated circuits for radio frequencies with high yield.

Ruecker, H.; Heinemann, B.; Knoll, D.; Ehwald, K.-E.

168

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

PubMed Central

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

Smitka, Martin; Malcho, Milan

2014-01-01

169

Microwave characterization and modeling of GaAs/AlGaAs heterojunction bipolar transistors  

NASA Technical Reports Server (NTRS)

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

Simons, Rainee N.; Romanofsky, Robert R.

1987-01-01

170

Defect study of GaInP/GaAs based heterojunction bipolar transistor emitter layer  

NASA Astrophysics Data System (ADS)

Defects in the emitter region of Ga0.51In0.49P/GaAs heterojunction bipolar transistors (HBTs) were investigated by means of deep-level transient spectroscopy. Both annealed (635 degC, 5 min) and as grown metalorganic chemical vapor deposition epitaxial wafers were investigated in this study, with an electron trap observed in the HBT emitter space-charge region from both wafers. The deep-level activation energy was determined to be 0.87plus-or-minus0.05 eV below the conduction band, the capture cross section 3 x10-14 cm2 and the defect density of the order of 1014 cm-3. This defect was also found to be localized at the emitter-base interface.

Cherkaoui, K.; Murtagh, M. E.; Kelly, P. V.; Crean, G. M.; Cassette, S.; Delage, S. L.; Bland, S. W.

2002-09-01

171

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

172

Thermal annealing induced bicontinuous networks in bulk heterojunction solar cells and bipolar field-effect transistors  

NASA Astrophysics Data System (ADS)

Polymer bulk heterojunction solar cells fabricated from poly(2,5-bis(3'-dodecyl-2,2'-bithiophen-5-yl)-3,6-dimethylthieno [3,2-b] thiophene):[6,6]-phenyl-C61-butric acid methyl ester (1:1, w/w) blend showed significantly improved power conversion efficiency (PCE), from 0.96% to 2.32%, with post-thermal annealing at 140 °C. Charge transport properties obtained from bipolar field-effect transistors indicated that post-thermal annealing induced the assembly of significantly improved bicontinuous networks and excellently balanced hole (7.2×10-3 cm2 V-1 s-1) and electron (5.8×10-3 cm2 V-1 s-1) mobilities (due, particularly, to improved electron mobility), thereby improving PCE.

Kong, Hoyoul; Moon, Ji Sun; Cho, Nam Sung; Jung, In Hwan; Park, Moo-Jin; Park, Jong-Hwa; Cho, Shinuk; Shim, Hong-Ku

2009-10-01

173

Low Turn-On Voltage and High-Current Double Heterojunction Bipolar Transistors  

Microsoft Academic Search

We report on the dc and microwave characteristics of an InP\\/In0.37Ga0.63As0.89Sb0.11\\/In0.53Ga0.47As double heterojunction bipolar transistor grown by solid-source molecular beam epitaxy. The pseudomorphic In0.37Ga0.63As0.89Sb0.11 base reduces the conduction band offset DeltaEC at the emitter\\/base junction and the base band gap, which leads to a very low VBE turn-on voltage of 0.35 V at 1 A\\/cm2. A current gain of 125

Shu-Han Chen; Kuo-Hung Teng; Hsin-Yuan Chen; Sheng-Yu Wang; Jen-Inn Chyi

2008-01-01

174

Proton irradiation effects on InGaP/GaAs single heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

The irradiation effects of low energy proton on both Direct Current (DC) and the Radio Frequency (RF) performance of InGaP/GaAs single heterojunction bipolar transistors (SHBTs) are investigated with fluence up to 5 × 1012 protons/cm2. The current gain in RF and the cutoff frequency (fT) show a little degradation even at proton fluence of 5 × 1012/cm2. The open-collector technique is used to extract the access resistances. Meanwhile 10 MeV proton irradiation is also investigated in order to compare the differences induced by different proton energies. The results indicate that InGaP/GaAs HBT is tolerant to proton irradiation.

Liu, Min; Zhang, Yuming; Lu, Hongliang; Zhang, Yimen; Zhang, Jincan; Wei, Zhichao; Li, Chenghuan

2014-06-01

175

Mechanisms leading to erratic snapback behavior in bipolar junction transistors with base emitter shorted  

NASA Astrophysics Data System (ADS)

This paper discusses two different modes of breakdown in the reverse-biased I-V characteristics observed generically in bipolar junction transistors (BJTs) with the base emitter shorted, showing an erratic behavior, in the presence of large displacement currents. Experimental observations related to reverse-biased collector junctions of BJTs, that exhibit two different states of breakdown when a fast voltage ramp is applied are presented. Numerical simulations of the transient behavior of avalanche injection in p/n-/n+ structures show that two very close breakdown states coexist. The mechanisms leading to the erratic behavior of the second breakdown are discussed. The jittery nature of the breakdown is attributed to the delay associated with the buildup of the electric field across the n-/n+ junction.

Chatterjee, Amitabh; Schrimpf, Ronald D.; Pendharkar, Sameer; Banerjee, Kaustav

2005-04-01

176

An analysis of the bias dependence of scattering parameters S11 and S22 of SiGe heterojunction bipolar transistors (HBTs)  

Microsoft Academic Search

The anomalous dip in scattering parameter S11 of SiGe heterojunction bipolar transistors (HBTs) is explained quantitatively for the first time. Our results show that for SiGe HBTs, the input impedance can be represented by a \\

Yo-Sheng Lin; Hsiao-Bin Liang; Shey-Shi Lu

2004-01-01

177

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

SciTech Connect

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

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

2006-12-01

178

The use of the electron-beam-induced current mode of the SEM for observing emitter\\/collector pipes in bipolar transistors  

Microsoft Academic Search

It is shown how the electron-beam-induced current (EBIC) mode of the SEM can be used to study the sites of emitter\\/collector pipes in bipolar transistors. In initial experiments the EBIC signal is collected across the collector and emitter of a bipolar transistor with the base floating, and it is observed that the pipes appear white (higher induced current) in comparison

P. Ashburn; C. J. Bull; J. R. A. Beale

1979-01-01

179

Investigation of an AlInAs/GaInAs superlattice-emitter resonant tunneling bipolar transistor (SE-RTBT)  

NASA Astrophysics Data System (ADS)

A new bipolar transistor with a 20-period i-AlInAs/n +-InGaAs superlattice, prepared by metal organic chemical vapour deposition, has been fabricated and demonstrated. This superlattice is used as a confinement barrier for holes and a resonant tunneling (RT) route for electrons. Due to the RT effect within the 20-period superlattice near emitter-base p-n junction region, the N-shaped negative-differential-resistance (NDR) phenomena are observed under normal operation. A transistor action with a common-emitter current gain of 13 and a small offset voltage (˜90 mV) is achieved at room temperature.

Cheng, S.-Y.; Chang, W.-L.; Liu, W.-C.; Lin, W.

1997-12-01

180

DC Characteristics of InAlAs\\/InGaAsSb\\/InGaAs Double Heterojunction Bipolar Transistors  

Microsoft Academic Search

DC electrical characteristics of a series of InAlAs\\/InGaAsSb\\/InGaAs double heterojunction bipolar transistors (DHBTs) that are grown on InP by molecular beam epitaxy are reported and analyzed. The InGaAsSb base of the transistors leads to a type-I base-emitter junction and a type-II base-collector junction, resulting in unique device characteristics, such as low turn-on voltage, low crossover current, and constant current gain

Shu-Han Chen; Chao-Min Chang; Pei-Yi Chiang; Sheng-Yu Wang; Wen-Hao Chang; Jen-Inn Chyi

2010-01-01

181

Comprehensive characterization of DC performance of n-p-n GaN-based bipolar transistors  

NASA Astrophysics Data System (ADS)

Poor ohmic contacts and high leakage current paths between terminals demand extra caution in characterizing GaN-based bipolar transistors properly and extracting useful information on intrinsic device performance. In the literature, interpretation of device performance varies widely. In some reports only common base operation was achieved [1]. Frequently common emitter characteristics and Gummel plots were reported at low current levels [2] and occasionally they were not consistent [3]. We find that in our devices common emitter I-Vs generally agree with Gummel plot and diode/leakage characteristics, and that device performance can be categorized to three rather distinct regions: 1) low current region dominated by base-collector leakage currents, 2) intermediate current region, manifesting base-emitter recombination current/leakage current and current gain flattening, 3) high current region, degraded by self-heating, possibly the Webster and Kirk effect. Devices analyzed in this work were fabricated using emitter regrowth technique with an emitter size of 20 × 50 ? m^2. [4] We find that owing to high leakage path coupled with poor terminal contacts, the extrinsic current gain bEXT measured at a low current level can be erroneously attributed to the gain of the intrinsic transistor ?_INT, which is generally much lower. As the current is increased, the effect of leakage currents is diminished, and ?_EXT arrow ?_INT. This model has been satisfactorily applied to explain both n-p-n and p-n-p bipolar transistor performance. In the intermediate current region we employed a 1-D temperature-dependent short emitter and long base model. The simulation shows that the electron minority carrier diffusion length L_nB or lifetime is the bottleneck in limiting ?. A value of L_nB = 0.32 ? m is deduced from our devices. The temperature influence on current gain is also found to be substantial for Al_xGa_1-xN/GaN HBTs with x_Al < 5. In the high current region our devices generally show a rather sharp drop in ?. Calculation of emitter current density distribution along the emitter width shows that the devices are indeed limited by the Kirk effect, accompanied by other high-injection effects. In short, we have carried out extensive study on current gain of GaN-based bipolar transistors, which provides insight in proper interpretation of device performance and device design. [1] Cao, X.A. et al., Solid-State Electronics, 44 (2000) 649-54 [2] Kumakura, K. et al., Applied Physics Letters, 80 (2002) 3841-3 [3] Shelton B. S. et al., IEEE Transactions on Electron Devices, 48 (2001) 490-4 [4] Limb, J. et al., Electronic Letters, 35 (1999) 1671-2

Xing, Huili; Mishra, Umesh

2003-03-01

182

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

183

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

SciTech Connect

A new GaAs junction-gated complementary logic technology that integrates a modulation doped p-channel heterostructure field effect transistor (pHFET) and a fully ion implanted n-channel JFET has recently been fabricated. High-speed, low-power operation has been demonstrated with loaded ring oscillators that show gate delays of 179 ps/stage for a power-delay product of 28 fJ at 1.2 V operation and 320 ps/stage and 8.9 fJ at 0.8 V operation. The principal advantages of this technology include the ability to independently set the threshold voltage of n- and p-channel devices and to independently design the pHFET for high performance. A self-aligned refractory gate process based on tungsten and tungsten silicide gate metal has been used to fabricate the FETs. Novel aspects of the fabrication include the simultaneous formation of non-alloyed, refractory ohmic contacts for the junction gates and the formation of shallow p-n junctions by ion implantation.

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

1994-10-01

184

GaAs/GaAlAs Bipolar Heterojunction Gate Array.  

National Technical Information Service (NTIS)

Several technological issues related to the development of GaAs bipolar heterojunction gate arrays were investigated experimentally using a test bar design tht consists of discrete transistors, three types of HI2L gates, and a prototype gate array with 11...

H. T. Yuan W. V. McLevige F. H. Doerbeck B. W. Cheney

1983-01-01

185

A GaAs\\/AlGaAs double-heterojunction device functioning as a bipolar transistor and injection laser for optoelectronic integrated circuits  

Microsoft Academic Search

A GaAs\\/AlGaAs double-heterojunction bipolar transistor (DHBT) is developed which also functions as a transverse-injection laser. The epitaxial layers for the DHBT's are grown by metalorganic vapor phase epitaxy (MOVPE). Experimentation reveals a transistor current gain of ? 10 and a pulsed lasing threshold of 230 mA at room temperature.

Yuji Hasumi; Atsuo Kozen; Jiro Temmyo; Hajime Asahi

1987-01-01

186

Linearisation des Amplificateurs de Puissance a Transistors a Effet de Champ GaAs en Hyperfrequences (Linearization of GaAs Field Effect Transistor Power Amplifiers in Hyperfrequences).  

National Technical Information Service (NTIS)

Methods to characterize the nonlinearities in hyperfrequency devices are studied showing that nonlinear transformation techniques are efficient to evaluate distorsions and intermodulation of GaAs MESFET power amplifiers. A computer program was developed t...

A. Loembe

1986-01-01

187

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

Microsoft Academic Search

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

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

1994-01-01

188

Characterization of leakage current related to a selectively grown collector in SiGeC heterojunction bipolar transistor structure  

NASA Astrophysics Data System (ADS)

Sources of base-collector and base-emitter leakage current in a SiGeC-based heterojunction bipolar transistor (HBT) with a selectively grown and chemical-mechanical polished (CMP) collector are discussed. Transmission electron microscopy and electrical measurement have been applied to investigate the leakage current. It has been demonstrated that the edge-located defects generated by selective epitaxy process are the origin of the junction leakage.

Suvar, E.; Haralson, E.; Radamson, H. H.; Wang, Y.-B.; Grahn, J. V.; Malm, B. G.; Östling, M.

2004-03-01

189

1.5 V operation sector-erasable flash memory with BIpolar Transistor Selected (BITS) P-channel cells  

Microsoft Academic Search

A novel BIpolar Transistor Selected (BITS) P-channel flash memory cell is proposed and a very low 1.5 V non-WL (word line)-boosting read and sector-erase operations are successfully achieved. Moveover, this cell technology not only maintains the advantages of the P-channel DINOR (DIvided bit line NOR) flash memory, but also realizes the amplification of cell current, which is favorable for fast

T. Ohnakado; N. Ajika; H. Hayashi; H. Takada; K. Kobayashi; K. Sugahara; S. Satoh; H. Miyoshi

1998-01-01

190

Thermal stability analysis of AlGaAs\\/GaAs heterojunction bipolar transistors with multiple emitter fingers  

Microsoft Academic Search

A numerical electro-thermal model was developed for AlGaAs\\/GaAs heterojunction bipolar transistors (HBT's) to describe the base current, current gain and output power dependence on junction temperature. The model is applied to microwave HBT devices with multi-emitter fingers. The calculated results of the common-emitter, current-voltage characteristics in the linear active region show a “current crush” effect due to inherent nonuniform junction

L. L. Liou; B. Bayraktaroglu

1994-01-01

191

Hot-carrier degradation and oxide charge build-up in self-aligned etched-polysilicon npn bipolar transistors  

Microsoft Academic Search

The authors present the results of several accelerated tests performed on self-aligned, etched-polysilicon, npn bipolar transistors with silicon dioxide emitter spacers, and propose a new technique for the characterization of the electric field at the periphery (i.e. at the interface between silicon and the silicon dioxide spacer) of the base-emitter junction. Tests are performed reverse-biasing at constant current the base-emitter

Andrea Neviani; Paolo Pavan; Alessandra Nardi; Alain Chantre; Loris Vendrame; Enrico Zanoni

1997-01-01

192

Multistep characteristics in Si\\/Si(x)Ge(1-x)\\/Si heterojunction bipolar transistor with delta-doped base  

Microsoft Academic Search

The authors report regenerative switching in an npn Si\\/Si(0.7)Ge(0.3)\\/Si heterojunction bipolar transistor with a delta-doped base. When operated in the avalanche regime the device exhibits switching characteristics in collector current against emitter-collector bias voltage. The I-V curve also shows multisteps between the OFF and ON states at room temperature, which may be due to the quantised energy levels formed by

F. Y. Huang; G. L. Zhou; H. Morkoc

1995-01-01

193

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

Microsoft Academic Search

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

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

1994-01-01

194

Total Ionizing Dose Testing of SiGe 7HP discrete Heterojunction Bipolar Transistors for ELDRS Effects  

Microsoft Academic Search

Thirty discrete heterojunction bipolar transistors fabricated in IBM's SiGe 7HP process were irradiated at dose rates of 0.013 rad(Si)\\/s, 0.11 rad(Si)\\/s and 171 rad(Si)\\/s to determine their sensitivity to total-dose irradiation and dose-rate effects. All devices tested showed less than 4% change in beta 0.6% change in turn on voltage. In addition, there was no measurable enhancement of degradation due

D. L. Hansen; S. Pong; P. Rosenthal; J. Gorelick

2007-01-01

195

Fd-Tlm Electromagnetic Field Simulation Of High-Speed Iii-V Heterojunction Bipolar Transistor Digital Logic Gates  

Microsoft Academic Search

The finite-difference transmission line matrix (FD-TLM) method allows us to model the electromagnetic behavior of a circuit based on material properties and package dimensions, without the necessity of circuit parasitic extraction. In this paper we extend the FD-TLM method to model micron-scale heterojunction bipolar transistors (HBTs) enabling us to perform time-domain, three-dimensional full-wave analysis of high-speed digital circuits containing HBTs.

Mayukh Bhattacharya; Pinaki Mazumder; Ronald J. Lomax

2001-01-01

196

4H-SiC bipolar junction transistors for UHF and L-band long-pulse radar applications  

Microsoft Academic Search

This paper reviews the current status of 4H-SiC RF npn bipolar junction transistors (BJT's). Process developments including precise and uniform SiC etch and low resistance p-type ohmic contact formation on a two inch SiC wafer will be presented. The high temperature operation up to 500°C and radiation hardness up to 1.6 Mrad, as well as RF performance promising for long-pulse

Feng Zhao; T. S. Sudarshan; Tiefeng Shi

2010-01-01

197

Accurate extraction method for 1\\/f-noise parameters used in Gummel-Poon type bipolar junction transistor models  

Microsoft Academic Search

In SPICE Gummel-Poon models one 1\\/f-noise source describes the low frequency noise behaviour of bipolar junction transistors (BJTs). In this paper we present a method to extract the respective model parameters from measured 1\\/f-noise data without the requirement of exactly determining the corner frequency fc, i.e. the frequency at which the 1\\/f-noise equals the device noise floor. This novel method

F. X. Sinnesbichler; M. Fischer; G. R. Olbrich

1998-01-01

198

Properties of AlGaAs\\/GaAs heterojunction bipolar transistor with AlGaAs ledge bypass capacitor  

Microsoft Academic Search

This paper proposes a device structure for enhancing thermal stability of a multi-finger power heterojunction bipolar transistor (HBT) with little sacrifice on RF properties. The proposed structure has an embedded base-ballast resistor and a bypass capacitor on each finger, which can be fabricated using a normal HBT process. It uses a p+-base layer and a depleted n-AlGaAs ledge to implement

T. K. Oh; J. G. Lee; K. H. Yi; C. H. Baek; B. U. Ihn; B. K. Kang

2002-01-01

199

Effect of surface treatment on electrical properties of AlGaAs\\/GaAs heterojunction bipolar transistor  

Microsoft Academic Search

This paper presents the effect of surface treatment on the electrical properties of an AlGaAs\\/GaAs heterojunction bipolar transistor (HBT). The extrinsic base surface of the HBT was treated in sequence with a (NH4)2Sx:H2O=1:1 solution, H2 plasma, and NH3 plasma. The treated HBT had a lower surface recombination current, base resistance, and low-frequency base current noise than the untreated HBT. These

C. H. Baek; T. K. Oh; B. K. Kang

2005-01-01

200

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

SciTech Connect

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

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

2011-12-15

201

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

202

Design and Performance of Microwave Amplifiers with GaAs Schottky-Gate Field-Effect Transistors  

Microsoft Academic Search

The design and performance of an X-band amplifier with GaAs Schottky-gate field-effect transistors are described. The amplifier achieves 20 ± 1.3-dB gain with a 5.5-dB typical noise figure (6.9 dB maximum) over the frequency range of 8.0-12.0 GHz. The VSWR at the input and output ports does not exceed 2.5:1. The minimum output power for 1-dB gain compression is +13

CHARLES A. LIECHTI; ROBERT L. TILLMAN

1974-01-01

203

Charge-collection efficiency of GaAs field effect transistors fabricated with a low-temperature grown buffer layer: Dependence on charge deposition profile  

Microsoft Academic Search

The dependence of the charge-collection processes of LT GaAs field-effect transistors on the depth profile of the deposited carriers is examined using computer simulation and laser-induced charge-collection measurements. The charge-collection simulations reveal a surprising dependence of the charge-collection efficiency on the location of the deposited charge, such that the charge-collection efficiency is largest for charge deposition below the LT GaAs

Dale McMorrow; Alvin R. Knudson; Joseph S. Melinger; Stephen Buchner

2000-01-01

204

Bias Dependence of Intermodulation Distortion Asymmetry in Heterojunction Bipolar Transistor Using Nonlinear Large-Signal Model  

NASA Astrophysics Data System (ADS)

The asymmetry between lower and upper intermodulation distortions (IMD) in a heterojunction bipolar transistor (HBT), which can be observed under certain baseband termination and bias conditions, is analyzed using a large-signal model. This approach enables harmonic balance analysis of IMD asymmetry in nonlinear circuits using HBTs and, therefore, overcomes the limitations of the conventional Volterra-series analysis. Closed-form expression derived from Volterra analysis is also employed to present comparisons with the large-signal model approach. Measurements indicate that the asymmetry is very sensitive to baseband termination, which varies with the envelope frequency of the input RF signal. Specifically, zero crossings of asymmetry are observed at each resonance frequency where the reactive part of baseband termination changes its sign rapidly. It is also found that the asymmetry is enhanced at a specific small bias current where the dominance of the 3rd order nonlinearity is greatly reduced by cancellation with the 2nd order nonlinearity. The bias condition for asymmetry occurrence is calculated, using a simple analytical equation, to be related to measurement data. All the measurements are verified successfully by nonlinear simulation using large-signal model. Finally, the advantage of the large-signal model approach compared to Volterra analysis for asymmetry prediction is discussed.

Park, Hyun-Min; Hong, Songcheol

2003-09-01

205

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

206

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

NASA Astrophysics Data System (ADS)

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

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

2006-04-01

207

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

208

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

PubMed

Loop heat pipes (LHPs) are used in many branches of industry, mainly for cooling of electrical elements and systems. The loop heat pipe is a vapour-liquid phase-change device that transfers heat from evaporator to condenser. One of the most important parts of the LHP is the porous wick structure. The wick structure provides capillary force to circulate the working fluid. To achieve good thermal performance of LHP, capillary wicks with high permeability and porosity and fine pore radius are expected. The aim of this work was to develop porous structures from copper and nickel powder with different grain sizes. For experiment copper powder with grain size of 50 and 100? ? m and nickel powder with grain size of 10 and 25? ? m were used. Analysis of these porous structures and LHP design are described in the paper. And the measurements' influences of porous structures in LHP on heat removal from the insulated gate bipolar transistor (IGBT) have been made. PMID:24959622

Nemec, Patrik; Smitka, Martin; Malcho, Milan

2014-01-01

209

Working toward high-power GaN/InGaN heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

III-nitride (III-N) heterojunction bipolar transistors (HBTs) are a less-explored electronic device technology due to the myriad research issues in material growth, device design and fabrication associated with these devices. For III-N HBTs, npn-GaN/InGaN heterostructures provide the benefits of mitigating the poor base electrical conductivity of p-type GaN and the problematic magnesium incorporation issues. Consequently, InGaN-base III-N HBTs are promising for next-generation high-power RF III-N systems. This paper will describe the current development status of npn GaN/InGaN HBTs grown either on sapphire or free-standing (FS) GaN substrates using optimized metalorganic chemical vapor deposition (MOCVD) and refined HBT processing techniques. Recombination current paths in GaN/InGaN HBTs are studied and small-signal equivalent circuits are developed. The extracted device model indicates that, with further device fabrication technique development, Johnson's figure of merit (JFOM) of GaN/InGaN HBTs can be as high as 5 THz V.

Shen, Shyh-Chiang; Dupuis, Russell D.; Lochner, Zachery; Lee, Yi-Che; Kao, Tsung-Ting; Zhang, Yun; Kim, Hee-Jin; Ryou, Jae-Hyun

2013-07-01

210

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

NASA Astrophysics Data System (ADS)

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

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

2001-10-01

211

High voltage operation (>80 V) of GaN bipolar junction transistors with low leakage  

NASA Astrophysics Data System (ADS)

We have demonstrated the high voltage operation of n-p-n GaN bipolar junction transistors using regrown emitters. Devices were grown by metalorganic chemical vapor deposition on sapphire substrates. The n-type emitter was grown selectively on a base-collector p-n junction diode using a dielectric mask. A thin base (1000 Å) was used to increase the current gain over our previous result with a regrown emitter [J. B. Limb, L. McCarthy, P. Kozodoy, H. Xing, J. Ibbetson, Y. Smorchkova, S. P. DenBaars, and U. K. Mishra, Electron. Lett. 35, 19 (1999)]. The base contacts were better than expected despite the use of a thin base. Common emitter operation showing a voltage operation of over 80 V with negligible leakage has been demonstrated. Room temperature current gain was ~3 corresponding to a current transfer ratio of ~0.75. This results in a calculated minority carrier lifetime of about 80 pS in the base.

Limb, J. B.; Xing, H.; Moran, B.; McCarthy, L.; Denbaars, S. P.; Mishra, U. K.

2000-04-01

212

The Bipolar Field-Effect Transistor: VII. The Unipolar Current Mode for Analog-RF Operation (Two-MOS-Gates on Pure-Base)  

NASA Astrophysics Data System (ADS)

This paper reports the DC steady-state current-voltage and conductance-voltage characteristics of a Bipolar Field-Effect Transistor (BiFET) under the unipolar (electron) current mode of operation, with bipolar (electron and hole) charge distributions considered. The model BiFET example presented has two MOS-gates on the two surfaces of a thin pure silicon base layer with electron and hole contacts on both edges of the thin base. The hole contacts on both edges of the thin pure base layer are grounded to give zero hole current. This 1-transistor analog-RF Basic Building Block nMOS amplifier circuit, operated in the unipolar current mode, complements the 1-transistor digital Basic Build Block CMOS voltage inverter circuit, operated in the bipolar-current mode just presented by us.

Binbin, Jie; Chih-Tang, Sah

2009-03-01

213

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

NASA Astrophysics Data System (ADS)

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

Zhu, Chendong

214

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

215

DLTS Studies of bias dependence of defects in silicon NPN bipolar junction transistor irradiated by heavy ions  

NASA Astrophysics Data System (ADS)

The characteristic degradation in silicon NPN bipolar junction transistors (BJTs) of 3DG130 type is examined under the irradiation with 35 MeV silicon (Si) ions under forward, grounded and reverse bias conditions, respectively. Different electrical parameters were in-situ measured during the exposure under each bias condition. Using deep level transient spectroscopy (DLTS), deep level defects in the base-collector junction of 3DG130 transistors under various bias conditions are measured after irradiation. The activation energy, capture cross section and concentration of observed deep level defects are measured using DLTS technique. Based on the in situ electrical measurement and DLTS spectra, it is clearly that the bias conditions could affect the concentration of deep level defects, and the displacement damage induced by heavy ions.

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

2012-10-01

216

Enhancing the current gain in InP/InGaAs double heterojunction bipolar transistors using emitter edge thinning  

NASA Astrophysics Data System (ADS)

This paper reports InP/InGaAs double heterojunction bipolar transistors (DHBTs) made with composite-collector designs. The current gains of the DHBTs without and with emitter edge-thinning designs are 125 and 180, respectively. The composition of the collector and the base currents is analysed from the Gummel plots. Experimental data demonstrate that emitter edge thinning can further reduce the surface recombination current of the InP/InGaAs DHBTs and thus dramatically improve current gain, even though the surface recombination in InP/InGaAs DHBTs is much less than in GaAs-based DHBTs.

Lin, Y. S.; Huang, D. H.; Hsu, W. C.; Su, K. H.; Wang, T. B.

2006-03-01

217

Lateral carrier diffusion and current gain in terahertz InGaAs/InP double-heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

The DC current gain in In0.53Ga0.47As/InP double-heterojunction bipolar transistors is computed based on a drift-diffusion model, and is compared with experimental data. Even in the absence of other scaling effects, lateral diffusion of electrons to the base Ohmic contacts causes a rapid reduction in DC current gain as the emitter junction width and emitter-base contact spacing are reduced. The simulation and experimental data are compared in order to examine the effect of carrier lateral diffusion on current gain. The impact on current gain due to device scaling and approaches to increase current gain are discussed.

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

2014-01-01

218

Surface passivation of lnP/ln0.53Ga0.47As heterojunction bipolar transistors for opto-electronic integration  

NASA Astrophysics Data System (ADS)

We report for the first time, a surface passivation technique for InP/In0.53Ga0.47As heterojunction bipolar transistors that is suitable for optoelectronic integrated circuits. The combination of buffered hydrofluoric acid with high temperature annealing of the surface causes significant increase of the gain at low input currents. Using this technique, transistors were integrated with photodetectors and other optoelectronic devices and had current gains as high as 400 even at nanoampere base currents.

Kim, Dong-Su; Chao, Chih-Ping; Beyzavi, Kian; Burrows, Paul E.; Forrest, Stephen R.

1996-03-01

219

Impact of carbon concentration on 1\\/f noise and random telegraph signal noise in SiGe:C heterojunction bipolar transistors  

Microsoft Academic Search

The influence of carbon concentration on the low-frequency noise (LF noise) of Si\\/SiGe:C\\/Si heterojunction bipolar transistors (HBTs) is investigated. When carbon is incorporated into these HBTs, representative noise spectra of the input current spectral density SIB show significant generation-recombination (GR) components. On the other hand, for transistors without carbon incorporation, no GR components were observed. When only 1\\/f noise component

J. Raoult; F. Pascal; C. Delseny; M. Marin; M. J. Deen

2008-01-01

220

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

221

Demonstration of enhancement-mode GaAs metal-insulator-semiconductor field effect transistor with channel inversion using Si3N4 as gate dielectric  

NASA Astrophysics Data System (ADS)

We report n-channel enhancement-mode GaAs metal-insulator-semiconductor Field Effect Transistors (MISFETs) with ~6 nm equivalent oxide thickness of molecular-and-atomic (MAD) depositioned Si3N4 as the gate dielectric. The GaAs based MISFETs were fabricated using a gate-first process that preserved the channel inversion characteristic in MIS capacitor structures [W. P. Li, X. W. Wang, Y. X. Liu, and T. P. Ma, Appl. Phys. Lett. 90, 193503 (2007)]. The channel inversion characteristics of the GaAs MIS capacitors, measured by the quasistatic C-V (capacitor-voltage) technique, were well maintained throughout the entire fabrication process with temperatures up to 800 °C. C-V hysteresis as small as 100 mV was achieved. The Si3N4-gated GaAs MISFETs clearly demonstrated the enhancement-mode, gate-modulated Id-Vd transfer characteristics with channel inversion.

Zheng, J. F.; Tsai, W.; Li, W. P.; Wang, X. W.; Ma, T. P.

2008-06-01

222

Transistor Nonlinear Damage.  

National Technical Information Service (NTIS)

The report summarizes the study of radiation induced surface degradation of (1) discrete planar transistors and (2) of devices in a silicon hybrid array (bipolar transistors, MOSFETS, MOS capacitors). The study of planar transistors, resulted in determini...

L. L. Sivo

1972-01-01

223

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

224

High-Efficiency and Highly Reliable 20 W GaAs Power Field-Effect Transistor in C Band  

NASA Astrophysics Data System (ADS)

This paper describes a high-performance and highly reliable GaAs field-effect transistor (FET) with a new gate structure employing the stepped gate recess combined with a multirefractory metal gate. This gate structure allows the simultaneous increase of maximum channel current and gate-drain breakdown voltage (Vgdo) of the FET and thus improves significantly its output power (Po) and power-added efficiency (?add). The resultant high Vgdo with highly stable gate Schottky characteristics and a novel surface stabilization prior to plasma-SiN passivation effectively suppress both catastrophic and gradual failures. The four-chip internally matched device (4× 12.6 mm) has delivered Po of 20 W at 1 dB gain compression with 39% ?add over 3.5 to 4.2 GHz. Sufficient reliability of the 20 W device available for satellite use has been assured by comprehensive reliability tests.

Sonoda, Takuji; Sakamoto, Shinichi; Kasai, Nobuyuki; Yamanouchi, Masahide; Takamiya, Saburo; Kashimoto, Yuzou

1992-08-01

225

Performance comparison of metalorganic vapor phase epitaxy grown C-doped GaAs/AlGaAs heterojunction bipolar transistor wafers between AsH 3 and trimethylarsenic for the base layer growth  

NASA Astrophysics Data System (ADS)

C-doped GaAs layers were grown with AsH 3 and As trimethylarsenic (TMAs) for the As source by a production scale metalorganic vapor phase epitaxy machine. In both cases, highly ( p = (1-4) x 10 19 cm -3) p-type C-doped GaAs layers were grown and no significant difference in their mobilities, carbon activation ratios and electron lifetimes were observed. By means of these methods, GaAs/AlGaAs heterojunction bipolar transistor (HBT) layers were grown and HBT test devices were fabricated. Current gains up to the base layer concentration of 3 x 10 19cm -3 were almost equal for these two methods, but at a concentration of p = 4 x 10 19 cm -3, the current gain of HBT whose base layer was grown with AsH 3 decreased rapidly. On the other hand, a current gain as high as 100 was demonstrated for a HBT whose base layer was grown with TMAs and was 4 x 10 19 cm -3 in concentration.

Tanaka, S.; Kato, S.; Hattori, S.; Kojima, S.; Ikeda, M.; Kitamura, K.

1994-12-01

226

InP/InGaAs Heterojunction Bipolar Transistors Grown on Ge/P Co-implanted InP Substrates by Metal-Organic Molecular Bean Epitaxy.  

National Technical Information Service (NTIS)

InP/InGaAs Heterojunction Bipolar Transistors (HBTs) have demonstrated excellent high- frequency performance 1-4 and are widely used for optical fiber transmission 5-7. However; the current mesa HBT structure utilizes a very thick, highly doped n+InGaAs l...

C. T. Liu D. J. Werder R. F. Kopf W. J. Sung Y. K. Chen

2002-01-01

227

Analytical base-collector depletion capacitance in vertical SiGe heterojunction bipolar transistors fabricated on CMOS-compatible silicon on insulator  

Microsoft Academic Search

The base---collector depletion capacitance for vertical SiGe npn heterojunction bipolar transistors (HBTs) on silicon on insulator (SOI) is split into vertical and lateral parts. This paper proposes a novel analytical depletion capacitance model of this structure for the first time. A large discrepancy is predicted when the present model is compared with the conventional depletion model, and it is shown

Xiao-Bo Xu; He-Ming Zhang; Hui-Yong Hu; Jian-Li Ma; Li-Jun Xu

2011-01-01

228

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

229

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

SciTech Connect

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

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

2011-05-15

230

Physical modeling based on hydrodynamic simulation for the design of InGaAs/InP double heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

A physical model for scaling and optimizing InGaAs/InP double heterojunction bipolar transistors (DHBTs) based on hydrodynamic simulation is developed. The model is based on the hydrodynamic equation, which can accurately describe non-equilibrium conditions such as quasi-ballistic transport in the thin base and the velocity overshoot effect in the depleted collector. In addition, the model accounts for several physical effects such as bandgap narrowing, variable effective mass, and doping-dependent mobility at high fields. Good agreement between the measured and simulated values of cutoff frequency, ft, and maximum oscillation frequency, fmax, are achieved for lateral and vertical device scalings. It is shown that the model in this paper is appropriate for downscaling and designing InGaAs/InP DHBTs.

Ge, Ji; Liu, Hong-Gang; Su, Yong-Bo; Cao, Yu-Xiong; Jin, Zhi

2012-05-01

231

Passivation of InP heterojunction bipolar transistors by strain controlled plasma assisted electron beam evaporated hafnium oxide  

NASA Astrophysics Data System (ADS)

We present structural, stress, and electrical properties of plasma assisted e-beam evaporated hafnium dioxide (HfO2) layers on n-type InP substrates. These layers have subsequently been used for surface passivation of InGaAs/InP heterostructure bipolar transistors either alone or in combination with plasma enhanced chemical vapor deposited SiO2 layers. The use of stacked HfO2/SiO2 results in better interface quality with InGaAs/InP heterostructures, as illustrated by smaller leakage current and improved breakdown voltage. These improvements can be attributed to the reduced defect density and charge trapping at the dielectric-semiconductor interface. The deposition at room temperature makes these films suitable for sensitive devices.

Driad, R.; Sah, R. E.; Schmidt, R.; Kirste, L.

2012-01-01

232

Spin-charge separation in bipolar spin transport in (111) GaAs quantum wells  

NASA Astrophysics Data System (ADS)

We present a microscopic theory for transport of the spin polarized charge density wave with both electrons and holes in the (111) GaAs quantum wells. We analytically show that, contradicting to the commonly accepted belief, the spin and charge motions are bound together only in the fully polarized system but can be separated in the case of low spin polarization or short spin lifetime even when the spatial profiles of spin density wave and charge density wave overlap with each other. We further show that, the Coulomb drag between electrons and holes can markedly enhance the hole spin diffusion if the hole spin motion can be separated from the charge motion. In the high-spin polarized system, the Coulomb drag can boost the hole spin diffusion coefficient by more than one order of magnitude.

Weng, M. Q.; Wu, M. W.

2013-11-01

233

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

234

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

235

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

PubMed

In this study, we propose a novel biosensor based on a gated lateral bipolar junction transistor (BJT) for biomaterial detection. The gated lateral BJT can function as both a BJT and a metal-oxide-semiconductor field-effect transistor (MOSFET) with both the emitter and source, and the collector and drain, coupled. C-reactive protein (CRP), which is an important disease marker in clinical examinations, can be detected using the proposed device. In the MOSFET-BJT hybrid mode, the sensitivity, selectivity, and reproducibility of the gated lateral BJT for biosensors were evaluated in this study. According to the results, in the MOSFET-BJT hybrid mode, the gated lateral BJT shows good selectivity and reproducibility. Changes in the emitter (source) current of the device for CRP antigen detection were approximately 0.65, 0.72, and 0.80 ?A/decade at base currents of -50, -30, and -10 ?A, respectively. The proposed device has significant application in the detection of certain biomaterials that require a dilution process using a common biosensor, such as a MOSFET-based biosensor. PMID:21835604

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

2011-10-15

236

A 1800 V, 300 A nondestructive RBSOA tester for bipolar transistors  

Microsoft Academic Search

The design and fabrication of a 1800 V, 300 A nondestructive transistor reverse-bias second breakdown (RBSB) tester are reported. An innovative MOSFET shunt circuit is the key to the high power capability of the tester. Its operation is described and comprehensive test results are presented.

G. Carpenter; F. C. Lee; D. Y. Chen

1988-01-01

237

Transistor used as an adjustable bipolar low-level DC source  

Microsoft Academic Search

The use of a saturated transistor with a collector current opposite to the usual leads to a versatile, stable, and easily adjustable dc source with an EMF ranging from -10 to +10 mV and a low temperature drift. This source may be used to compensate the input offset voltage of a monolithic opamp whenever the impedance must be kept near

G. R. Fontaine

1972-01-01

238

An analysis of the anomalous dip in scattering parameter S22 of InGaP-GaAs heterojunction bipolar transistors (HBTs)  

Microsoft Academic Search

The kink phenomenon in scattering parameter S22 of InGaP-GaAs heterojunction bipolar transistors (HBTs) was explained quantitatively for the first time. Our results show that the output impedance of InGaP-GaAs HBTs can be represented by a simple series resistance-capacitance (R-C) circuit at low frequencies and a simple parallel R-C circuit at high frequencies very accurately because of the high output resistance

Hsing-Yuan Tu; Yo-Sheng Lin; Ping-Yu Chen; Shey-Shi Lu; Hsuan-Yu Pan

2002-01-01

239

Analysis and compact modeling of a vertical grounded-base NPN bipolar transistor used as an ESD protection in a smart power technology  

Microsoft Academic Search

A thorough analysis of the physical mechanisms involved in a vertical grounded-base NPN bipolar transistor (VGBNPN) under ESD stress is first carried out by 2D-device simulation, square pulse measurements (TLP) and photoemission experiments. As a result, we propose a compact model using a new physics-based avalanche formulation. This allows reproduction of the unexpected low value of the VGBNPN snapback holding

G. Bertrand; C. Delage; M. Bafleur; N. Nolhier; J. M. Dorkel; Q. Nguyen; N. Mauran; P. Perdu

2000-01-01

240

Heavy-ion broad-beam and microprobe studies of single-event upsets in 0.20-?m SiGe heterojunction bipolar transistors and circuits  

Microsoft Academic Search

Combining broad-beam circuit level single-event upset (SEU) response with heavy ion microprobe charge collection measurements on single silicon-germanium heterojunction bipolar transistors improves understanding of the charge collection mechanisms responsible for SEU response of digital SiGe HBT technology. This new understanding of the SEU mechanisms shows that the right rectangular parallel-piped model for the sensitive volume is not applicable to this

Robert A. Reed; Paul W. Marshall; James C. Pickel; Martin A. Carts; Bryan Fodness; Guofu Niu; Karl Fritz; Gyorgy Vizkelethy; Paul E. Dodd; Tim Irwin; John D. Cressler; Ramkumar Krithivasan; Pamela Riggs; Jason Prairie; Barbara Randall; Barry Gilbert; Kenneth A. LaBel

2003-01-01

241

Low 1\\/f noise and DC offset RF mixer for direct conversion receiver using parasitic vertical NPN bipolar transistor in deep n-well CMOS technology  

Microsoft Academic Search

RF characteristics of the parasitic vertical NPN bipolar junction transistor (BJT) available in 0.18 ?m foundry deep n-well CMOS technology are reported for the first time. The experimental results show that the vertical NPN BJT has about 20 of current gain, 7 V of collector-emitter breakdown voltage, 20 V of collector-base breakdown voltage, 40 V of early voltage, 2.3 GHz

Ilku Nam; Young Jin Kim; Kwyro Lee

2003-01-01

242

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

Microsoft Academic Search

4H-SiC NPN bipolar junction transistor (BJT) is studied systematically by performing two-dimensional numerical simulations. Several design issues are discussed. Depending on the doping concentration of the base and the carrier lifetimes, both positive and negative temperature coefficients in the common emitter current gain could exist in 4H-SiC NPN BJTs with aluminium-doped base. The temperature coefficients of the current gain at

X. Niu; H. Fardi

2011-01-01

243

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

Microsoft Academic Search

4H-SiC NPN bipolar junction transistor (BJT) is studied systematically by performing two-dimensional numerical simulations. Several design issues are discussed. Depending on the doping concentration of the base and the carrier lifetimes, both positive and negative temperature coefficients in the common emitter current gain could exist in 4H-SiC NPN BJTs with aluminium-doped base. The temperature coefficients of the current gain at

X. Niu; H. Fardi

2012-01-01

244

Radiation effects on silicon bipolar transistors caused by 3–10 MeV protons and 20–60 MeV bromine ions  

Microsoft Academic Search

The current gain degradation in silicon NPN bipolar junction transistors (BJTs) was examined under irradiation with 3–10MeV protons and 20–60MeV bromine (Br) ions with various dose levels. To characterize the radiation damage of the NPN BJTs, the ionizing dose Di and displacement dose Dd as a function of chip depth in the NPN BJTs were calculated for both the protons

Xingji Li; Hongbin Geng; Mujie Lan; Chaoming Liu; Dezhuang Yang; Shiyu He

2010-01-01

245

Measurement and comparison of 1\\/f noise and g-r noise in silicon homojunction and III-V heterojunction bipolar transistors  

Microsoft Academic Search

This paper experimentally determines and compares the 1\\/f noise and the g-r noise, as components of the base noise current spectral density, in Si homojunction and III-V heterojunction bipolar transistors (HBTs) in common-emitter configuration. The noise spectra for each of these devices are obtained as functions of the base bias current (IB), and the 1\\/f noise has been found to

Ashish K. Kirtania; Mukunda B. Das; S. Chandrasekhar; Leda M. Lunardi; G.J. Qua; R. A. Hamm; Li-Wu Yang

1996-01-01

246

Coupled bipolar transistors as very robust ESD protection devices for automotive applications  

Microsoft Academic Search

ESD requirements for automotive applications are demanding and diverse. Coupled bipolar ESD protection devices within a BCD technology are realized having a system level HBM-gun (330 Omega\\/150 pF) robustness of more than 10 kV with the thyristor mode being avoided. The change from rectangular to circular device geometry leads to an increase in device robustness with respect to device level

Nils Jensen; Gerhard Groos; Marie Denison; Jan Kuzmik; Dionyz Pogany; Erich Gornik; Matthias Stecher

2003-01-01

247

Numerical simulation of avalanche breakdown in PIN diodes and bipolar transistors  

Microsoft Academic Search

Numerical simulation of avalanche breakdown in bipolar power semiconductors by modeling impact ionization directly in the basic semiconductor equations is described. Use of the sequential Gummel solution algorithm permits more frequent updating of the impact ionization term, leading to better convergence than with the simultaneous Newton algorithm. Results are presented for a reverse-biased PIN diode and for the reverse-biased collector-base

R. M. O'Connell; T. Shiue; R. G. Hoft

1992-01-01

248

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.

249

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

NASA Technical Reports Server (NTRS)

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

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

1986-01-01

250

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

NASA Astrophysics Data System (ADS)

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

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

2010-04-01

251

3-D simulation of angled strike heavy-ion induced charge collection in silicon–germanium heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

This paper presents 3-D simulation of angled strike heavy-ion induced charge collection in domestic silicon–germanium heterojunction bipolar transistors (SiGe HBTs). 3D damaged model of SiGe HBTs single-event effects (SEE) is built by TCAD simulation tools to research ions angled strike dependence. We select several different strike angles at variously typical ions strike positions. The charge collection mechanism for each terminal is identified based on analysis of the device structure and simulation results. Charge collection induced by angled strike ions presents a complex situation. Whether the location of device ions enters, as long as ions track through the sensitive volume, it will cause vast charge collection. The amount of charge collection of SiGe HBT is not only related to length of ions track in sensitive volume, but also influenced by STI and distance between ions track and electrodes. The simulation model is useful to research the practical applications of SiGe HBTs in space, and provides a theoretical basis for the further radiation hardening.

Jinxin, Zhang; Hongxia, Guo; Lin, Wen; Qi, Guo; Jiangwei, Cui; Xin, Wang; Wei, Deng; Qiwen, Zhen; Xue, Fan; Yao, Xiao

2014-04-01

252

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

253

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

254

A cryogenic GaAs HBT microwave amplifier and its application to a superconductor digital IC  

Microsoft Academic Search

The first microwave GaAs HBT (heterojunction bipolar transistor) amplifier results at 4.2 K are benchmarked. The amplifier nominal gain is 6 dB and is measured from 130 MHz to 10 GHz at fixture temperatures of 295 K, 77 K, and 4.2 K. The maximum gain variation over temperature was found to be about 2 dB. Maximum gain occurred at temperatures

K. W. Kobayashi; J. H. Kobayashi; M. Leung; A. K. Oki; M. Matloubian; S. Chan; D. C. Streit

1993-01-01

255

Design and Performance of X-Band Oscillators with GaAs Schottky-Gate Field-Effect Transistors  

Microsoft Academic Search

The circuit construction and design of an X-band oscillator with a GaAs Schottky-gate FET have been studied. The oscillation characteristics including stability and noise performance have been examined in order to clarify the position of a GaAs FET as a microwave solid-state oscillator device. The experiments have revealed that 1) the GaAs FET simultaneously possesses the most desirable features of

MINORU MAEDA; KATSUHIRO KIMURA; HIROSHI KODERA

1975-01-01

256

InP/InGaAs heterojunction bipolar transistors and field-effect transistors grown by gas-source molecular beam epitaxy  

NASA Astrophysics Data System (ADS)

Both InP/InGaAs heterojunction bipolar transistor (HBT) and heterojunction field effect transistor (HFET) technologies have demonstrated excellent device cutoff frequency and record-setting circuit performance. This thesis is on the development of gas-source molecular beam epitaxy (GSMBE) material growth and device fabrication technologies for InP/InGaAs BiFET. A systematic investigation of the Schottky characteristics of metal/Ga 0.2In0.8P/InP structures has shown that barrier heights of 0.6--0.7 eV can be achieved for Schottky junctions formed on Ga 0.2In0.8P/InP. No degradation in the Schottky characteristics is observed at temperatures as high as 250°C. InP/InGaAs doped-channel HFETs with Ga0.2In0.8P Schottky barrier enhancement layers (SBEL) were grown and fabricated. The 0.15-mum-gate-length devices show excellent dc and RF performance. The extrinsic dc transconductance of the HFET is 716 mS/mm, and the fT and the fmax are values of 171 and 186 GHz, respectively. These fT and fmax are also comparable to those of other works of InGaAs channel HEMTs with the same gate length. High material quality C-doped InGaAs layers and Npn InP/InGaAs HBTs have been successfully grown by GSMBE. For standard HBT devices employing InGaAs contacting layers, the excellent device performance validates the GSMEBE-grown material quality. For dc performance, these devices showed good Gummel characteristics with nc = 1.02--1.08 and nb = 1.17--1.2. The gain (beta) variation for different devices was found to be proportional to the square of the base sheet resistance (Rsb2) which indicates the minority electron lifetime in the base region is limited by diffusive base and Auger recombination. For high frequency measurements of 3 X 10 mum2 emitter area devices (700-A base /4000-A collector), the peak fT of 108 GHz was observed at an Ic of 21 mA with a corresponding fmax of 128 GHz. These values are comparable to those for C-doped base devices grown by metalorganic molecular beam epitaxy (MOMBE) and similar structures grown using Be as the p-type dopant. To further improve high frequency performance, standard HBTs (500-A base /3000-A collector) with graded emitter contact composed of In0.75Ga0.25As (250-A)/graded-InGaAs (500-A)/In 0.53Ga0.47As (750-A) were grown. Finally, the thermal degradation of heavily C-doped InGaAs and its effects on dc properties of InGaAs/InP HBTs have been studied. The degradation of the junction properties and current gain-base sheet resistance ratio can be attributed to the formation of C precipitates. These findings are important for improving the reliability of C-doped InP/InGaAs HBTs. (Abstract shortened by UMI.)

Kuo, Hao-Chung

1999-12-01

257

GaAs FET IMD demands better standard  

NASA Astrophysics Data System (ADS)

The third-order intercept point is an imaginary power level used to indicate the linearity performance of a 'well-behaved' power amplifier such as a bipolar transistor. Unfortunately, GaAs FET power amplifiers are by no means well-behaved devices. In fact, for most GaAs FET power amplifiers, the third-order intercept point is a meaningless term. However, more consistent ways of gauging linearity are available. A simple two-tone test, for example, could be developed into a standardized reference which could be applied uniformly throughout the industry. Digital radio presents an example of the manner in which this system could work. A graph is provided showing the performance of four GaAs FET linear amplifiers measured under large signal conditions.

Hsieh, C.

1982-06-01

258

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

259

Heavy-ion broad-beam and microprobe studies of single-event upsets in 0.20 um SiGe heterojunction bipolar transistors and circuits.  

SciTech Connect

Combining broad-beam circuit level single-event upset (SEU) response with heavy ion microprobe charge collection measurements on single silicon-germanium heterojunction bipolar transistors improves understanding of the charge collection mechanisms responsible for SEU response of digital SiGe HBT technology. This new understanding of the SEU mechanisms shows that the right rectangular parallele-piped model for the sensitive volume is not applicable to this technology. A new first-order physical model is proposed and calibrated with moderate success.

Fritz, Karl (Mayo Foundation, Rochester, MN); Irwin, Timothy J. (Jackson & Tull Chartered Engineers, Washington, DC); Niu, Guofu (Auburn University, Auburn, AL); Fodness, Bryan (SGT, Inc., Greenbelt, MD); Carts, Martin A. (Raytheon ITSS, Greenbelt, MD); Marshall, Paul W. (Brookneal, VA); Reed, Robert A. (NASA/GSFC, Greenbelt, MD); Gilbert, Barry (Mayo Foundation, Rochester, MN); Randall, Barbara (Mayo Foundation, Rochester, MN); Prairie, Jason (Mayo Foundation, Rochester, MN); Riggs, Pam (Mayo Foundation, Rochester, MN); Pickel, James C. (PR& T, Inc., Fallbrook, CA); LaBel, Kenneth (NASA/GSFC, Greenbelt, MD); Cressler, John D. (Georgia Institute of Technology, Atlanta, GA); Krithivasan, Ramkumar (Georgia Institute of Technology, Atlanta, GA); Dodd, Paul Emerson; Vizkelethy, Gyorgy

2003-09-01

260

Analytical description of the injection ratio of self-biased bipolar transistors under the very high injection conditions of ESD events  

NASA Astrophysics Data System (ADS)

This paper proposes a 1D-analytical description of the injection ratio of a self-biased bipolar transistor under very high current injection conditions. Starting from an expression of the current gain based on the stored charge into the emitter and base regions, we derive a new analytical expression of the current injection ratio. This analytical description demonstrates the presence of an asymptotic limit for the injection ratio at very high current densities, as the ratio of electron/hole mobilities in the case of an NPN transistor and to the ratio of hole/electron saturation velocities for a PNP. Moreover, for the first time, a base narrowing effect is demonstrated and explained in the case of a self-biased PNP, in contrast with the base widening effect (Kirk effect [Kirk CT, A theory of transistor cutoff frequency (fT) falloff at high current densities, IRE Trans Electr Dev 1961: p. 164-73]) reported for lower current density. These results are validated by numerical simulation and show a good agreement with experimental characterizations of transistors especially designed to operate under extreme condition such as electrostatic discharge (ESD) events.

Gendron, A.; Renaud, P.; Bafleur, M.; Nolhier, N.

2008-05-01

261

The influence of heavily doped buried layer implants on electrostatic discharge (ESD), latchup, and a silicon germanium heterojunction bipolar transistor in a BiCMOS SiGe technology  

Microsoft Academic Search

This paper will demonstrate the effect of heavily doped buried layers (HDBL) on electrostatic discharge protection, latchup, and silicon germanium (SiGe) heterojunction bipolar transistors (HBT). Heavily doped buried layers (HDBL) implants, in prior publications, have demonstrated improvements in latchup robustness in low-doped substrate wafer technology. The influence of HDBL on MOSFET ESD protection has also been demonstrated. In this paper,

S. Voldman; L. Lanzerotti; W. Morris; L. Rubin

2004-01-01

262

Monolithic integration of 1.3-?m InGaAs photodetectors and high-electron-mobility transistor (HEMT) electronic circuits on GaAs  

NASA Astrophysics Data System (ADS)

For the first time, monolithic optoelectronic receivers for a wavelength of 1.3 micrometers have been fabricated successfully on GaAs substrates using InGaAs metal-semiconductor-metal (MSM) photodiodes and AlGaAs/GaAs/AlGaAs high-electron-mobility transistors (HEMTs). Using molecular beam epitaxy (MBE), the photodetector layers were grown on top of a double (delta) -doped AlGaAs/GaAs/AlGaAs HEMT structure which allows the fabrication of enhancement and depletion field effect transistors. The photoabsorbing InGaAs layer was grown at 500 degree(s)C. To fabricate the optoelectronic receivers, first, an etch process using a combination of non-selective wet etching and selective reactive ion etching was applied to produce mesas for the photoconductors and to uncover the HEMT structure in all other areas. For the electronic circuits, our well-established HEMT process for 0.3-micrometers transistor gates was used which includes electron-beam lithography for gate definition and optical lithography for NiCr thin films resistors, capacitors, and inductors. The interdigitated MSM photodiode fingers were also fabricated using electron-beam lithography. For interconnecting the electronic circuits and the photodetectors, air bridges were employed. The entire process was performed on 2-inch wafers with more than 90% yield of functional receivers. The finished receiver--basically an MSM photodetector linked to a transimpedance amplifier--is operational at an incident wavelength of 1.3 micrometers at data rates up to 1.2 Gbit/s. The sensitivity of the detectors is 0.16 A/W at a 10 V bias.

Fink, Thomas; Hurm, Volker; Raynor, Brian; Koehler, Klaus; Benz, Willy; Ludwig, M.

1995-04-01

263

Effect of circuital currents on the speed and efficiency of picosecond-range switching in a GaAs avalanche transistor  

NASA Astrophysics Data System (ADS)

Ultrafast (picosecond range) switching of a GaAs-based BJT (bipolar junction transistor) in the avalanche mode has recently been demonstrated experimentally. It was found to be caused by the formation and spread of ultra-high amplitude multiple Gunn domains, which cause extremely powerful avalanching in the volume of the switching filaments. Unavoidable parasitic impedance of an external circuit limits the rate of avalanche carrier generation in the channels, however, which slows down the switching and increases the residual voltage across the switch. We present here the results of simulations which show that the switching transient can be significantly accelerated and the residual voltage reduced due to the supporting of a higher current density in the channels by the charge stored in the barrier capacitance of the non-switched part of the structure. The corresponding circuital currents are confined in low-inductance loops inside the structure and are not critically affected by the parameters of the external circuit. This provides very fast and effective reduction in the collector voltage, provided the parameters of the semiconductor layers and the geometry of the device are selected properly. Particularly significant in this process is the effect of circuital current saturation in the lightly doped collector region of the non-switched part of the transistor. The results of the simulations with the barrier capacitance included in the model are in excellent agreement with the experimental data.

Vainshtein, Sergey; Yuferev, Valentin; Kostamovaara, Juha

2005-04-01

264

ELDRS in Bipolar Linear Circuits: A Review  

Microsoft Academic Search

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

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

2009-01-01

265

ELDRS in bipolar linear circuits: A review  

Microsoft Academic Search

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

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

2008-01-01

266

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

NASA Astrophysics Data System (ADS)

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

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

2006-02-01

267

Characterisation of Heterojunction Bipolar Transistors incorporating Si\\/Si1-xGex epitaxial double layers with n+ emitter implants  

Microsoft Academic Search

Transistors fabricated with systematic variations in Ge fraction, base doping and junction spacer width show near-ideal electrical characteristics. Emitter implantation generates anomalous boron diffusion in the base.

D J Robbins; W Y Leong; J L Glasper; A J Pidduck; R Jackson; I R C Post; Z A Shafi; P Ashburn

1992-01-01

268

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

NASA Astrophysics Data System (ADS)

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 1×1015 cm-2 dose, we achieved a subcollector sheet resistance of 15 ?/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+ 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+-doped InP substrates.

Hu, Ting-Chen; Chang, M. F.; Weimann, Nils; Chen, Jianxin; Chen, Young-Kai

2005-04-01

269

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

NASA Astrophysics Data System (ADS)

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

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

2011-11-01

270

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

271

50-200 GHz Silicon-Germanium Heterojunction Bipolar Transistor BICMOS Technology and a Computer-Aided Design Environment for 2--50+ GHz Very Large-Scale Integration Mixed-Signal ICs  

Microsoft Academic Search

Silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) BICMOS technology is a stable, ultra-high performance, semiconductor technology capable of supporting mixed-signal, very large-scale integration (VLSI) circuit designs for a variety of emerging communication applications. This technology is supported by a computer-aided design (CAD) system that supports a variety of high-performance circuit designs, mixed-signal circuit block reuse, and the ability to accurately predict

Seshadri Subbanna; Gregory Freeman; Jae-Sung Rieh; David Ahlgren; Kenneth Stein; Carl Dickey; James Mecke; Peter Bacon; Robert Groves; Mounir Meghelli; Mehmet Soyuer; Basanth Jagannathan; Kathryn Schonenberg; Shwu-Jen Jeng; Alvin Joseph; Douglas Coolbaugh; Richard Volant; David Greenberg; Huajie Chen; Kevin Brelsford; David Harame; James Dunn; Lawrence Larson; Dean Herman Jr.; Bernard Meyerson

2002-01-01

272

Very low cost graded SiGe base bipolar transistors for a high performance modular BiCMOS process  

Microsoft Academic Search

We report a new super self-aligned graded SiGe base transistor that uses high energy implantation, rather than epitaxial growth, to form the sub-collector region. This new inexpensive process yields a device with fT of 52 GHz and fmax of 70 GHz with the addition of only 4 lithography levels over our 0.25 ?m CMOS technology without any changes to the

C. A. King; M. R. Frei; M. Mastrapasqua; K. K. Ng; Y. O. Kim; R. W. Johnson; S. Moinian; S. Martin; H.-I. Cong; F. P. Klemens; R. Tang; D. Nguyen; T.-I. Hsu; T. Campbell; S. J. Molloy; L. B. Fritzinger; T. G. Ivanov; K. K. Bourdelle; C. Lee; Y.-F. Chyan; M. S. Carroll; C. W. Leung

1999-01-01

273

High-voltage operation with high current gain of pnp AlGaN/GaN heterojunction bipolar transistors with thin n-type GaN base  

NASA Astrophysics Data System (ADS)

A pnp AlGaN/GaN heterojunction bipolar transistor (HBT) with a thin n-GaN base shows high-voltage operation with high current gain in the common-emitter configuration at room temperature. The device structure was grown by metalorganic vapor phase epitaxy on a sapphire substrate. The emitter area is 30 ?m×50 ?m. The HBT can operate at high voltage of 70 V with the maximum current gain of 40 at the collector current of 10 mA. The maximum output power density is 172 kW/cm2. Transport characteristics in the HBT were also investigated. At small collector current, the current gain is dominated by the recombination current at the emitter-base heterojunction. At moderate collector current, the calculated minority hole diffusion length well agreed with that determined from electron beam induced current measurements, indicating the current gain is dominated by the minority carrier diffusion. At large collector current, a high injection effect was observed in the current gain characteristics.

Kumakura, Kazuhide; Makimoto, Toshiki

2005-01-01

274

New Cu/Mo/Ge/Pd Ohmic Contacts on Highly Doped n-GaAs for InGaP/GaAs Heterojunction Bipolar Transistors  

NASA Astrophysics Data System (ADS)

The feasibility of using novel Cu/Mo/Ge/Pd ohmic contacts on n+-GaAs for heterojunction bipolar transistors (HBTs) is investigated. The electrical and material characteristics of the Cu/Mo/Ge/Pd/n+-GaAs structure were studied. After thermal annealing at 350 °C, the specific contact resistances of the copper ohmic contacts Cu/Mo/Ge/Pd were measured to be 2.8× 10-7 ? cm2. Judging from the data of sheet resistance, X-ray diffraction analysis, Auger electron spectroscopy, and transmission electron microscopy, the Cu/Mo/Ge/Pd contact structure was very stable after annealing at 350 °C. However, after 400 °C annealing, the reaction of copper with the underneath layers started to occur and formed MoGe2, Cu3Ga and Ge3Cu phases. An InGaP/GaAs HBT with Cu/Mo/Ge/Pd contact metals was fabricated and compared with an HBT fabricated with traditional Au/Ni/Ge/Au contact metals. These two kinds of HBTs showed similar device characteristics. After reaching thermal stability and performing a high current-accelerated stress test at a current density of 120 kA/cm2 for 24 h, the device with the Cu/Mo/Ge/Pd ohmic contacts still exhibits excellent electrical characteristics.

Chang, Chun-Wei; Hsieh, Tung-Ling; Chang, Edward Yi

2006-12-01

275

Application of III-V-Semiconductor based heterojunction bipolar transistors towards multi-Gbit/s 4: 1 multiplexer  

NASA Astrophysics Data System (ADS)

An HBT-based IC prototyping technology is being developed at The Royal Institute of Technology's Semiconductor Laboratory, aiming for transistor cut-off frequencies in the region of 70 GHz. Both AlGaAs/GaAs- and InP/InGaAs-HBTs have been fabricated showing cut-off- and maximum oscillation frequencies well above 60 GHz. The overall circuit technology is based on two level metallization separated by silicon-nitride for interconnects and MIM capacitors, and NiCr-based resistors. A 4: 1 time division multiplexer was targeted to explore the feasibility of the in-house technology for MSI circuit implementations, especially for broadband switching applications.

Schuppener, G.; Willčn, B.; Mokhtari, M.; Tenhunen, H.

1994-01-01

276

Characterization of Minority Carrier Transport and Heavy Doping Effects in N-SILICON/P-SILICON(1-X) Germanium(x)/n - Heterojunction Bipolar Transistors.  

NASA Astrophysics Data System (ADS)

The n-Si/p-Si_{rm 1 -x}Ge_{rm x} /n-Si heterojunction bipolar transistor (HBT) is one of the most promising devices for manufacturing Si -based ultra-fast circuits. The Si_{ rm 1-x}Ge_{rm x} layer is used as the base of the transistor and can be grown by a slight modification of Si technology. The purpose of this work is to experimentally characterize the effects of heavy doping on electron transport in p -type strained Si_{rm 1-x} Ge_{rm x}. The device and process design issues specific to the fabrication of heavily doped n-Si/p^+ -Si_{rm 1-x}Ge _{rm x}n-Si HBTs are outlined. Boron out-diffusion from the p^+ -Si_{rm 1-x}Ge _{rm x} base is significantly enhanced during 850^circC, 10 sec. rapid thermal annealing, following emitter contact implantation. Techniques which dramatically reduce boron out-diffusion during emitter contact implant activation are introduced. HBTs incorporating these techniques were fabricated to characterize the minority carrier transport parameters in p^+-Si_ {rm 1-x}Ge_{ rm x}. A.C. and D.C. measurements were used to independently extract the doping dependence of minority electron diffusivity (D_{ rm n}) and apparent dopant induced bandgap narrowing (DeltaE_ {rm g-app}) for p-type, strained Si_{rm 1-x}Ge _{rm x} layers ( ~10^{17} -10^{20} cm^ {-3}). The results indicate that DeltaE_{rm g-app } in Si_{rm 1-x} Ge_{rm x} is similar to that in Si for dopings <10 ^{19} cm^ {-3} but is smaller in Si_{1-x}Ge_{ rm x} at higher doping concentrations. This is attributed to the lower valence band density of states in Si_{1-x}Ge _{rm x}, which makes the effect of Fermi-Dirac statistics more pronounced. The dopant induced bandgap narrowing values, obtained after correcting for Fermi-Dirac statistics, are in good agreement with theoretical predictions. These results are important for modeling the current characteristics of high performance Si/Si_{rm 1-x}Ge _{rm x} HBTs.

Ghani, Tahir

1995-01-01

277

Investigation on effects of ion-implantation on indium phosphide and gallium arsenic antimonide for high fmax double heterojunction bipolar transistor  

NASA Astrophysics Data System (ADS)

InP/InGaAs Heterojunction Bipolar Transistors (HBTs) have demonstrated excellent high-frequency performance, operating up to 400 GHz, enabling mixed-signal integrated circuit applications at 160 GHz clock-speed and beyond. Traditionally, HBTs are manufactured in a triple-mesa process leading to topography height in excess of 1mum. Replacing the subcollector mesa by ion implantation directly into substrate prior to epilayer growth, the device height can be reduced. The capacitance under the base pad can be eliminated by selective ion implantation of the subcollector layer only under the emitter and in the collector contact region. Furthermore, the ion-implanted subcollector immersed in the InP substrate can relieve the thermal impedance problem of the InGaAs subcollector. This work is focused on the n+ ion-implanted subcollector technology, including sheet resistance optimization by choosing a suitable implant profile, minimizing ohmic contact resistance with optimized metal stack and anneal step. The device-quality can be enabled from the improved MBE regrowth layer by keeping the substrate surface roughness below a critical threshold, which was found empirically. The results of this work were implemented in the first 0.25 mum ion-implanted DHBT. The subtractive technology of damage implantation will be discussed in the context of an additional reduction of the base-collector capacitance. Further, p-type implantation experiments have been carried out to explore the possibility to lower the base access resistance by converting part of the extrinsic collector to p-type. To that end, some results will be presented regarding carbon implantation into InP and GaAsSb.

Hu, Ting-Chen

278

Probing plasma-surface interactions with the transmission electron microscope or the Si-collector interface of the plasma bipolar junction transistor  

NASA Astrophysics Data System (ADS)

Two platforms developed to probe the plasma-solid interface are briefly reviewed here. A sensitive diagnostic of the interaction between a low-temperature plasma and a silicon surface is provided by the plasma bipolar junction transistor (PBJT) in which e--h+ (semiconductor) and e--ion (gas phase) plasmas are separated by a nanoscale potential barrier but coupled by a strong (>1 V µm-1) electric field. Electrical properties of the Si base-collector plasma interface are controlled by the bias applied to the PBJT emitter-base junction, as well as the morphology and electronic structure of the base surface facing the collector plasma. Recent experiments are described in which the Si(100) surface of the PBJT base is transformed into black Si, a nanostructured array comprising ˜3 × 109 nanocones. Each cone is ˜100 nm in height and has a radius of curvature at its tip of <1 nm. Altering the base surface so as to intentionally enhance field emission results in burst-mode operation of the PBJT in which the collector current oscillates as a result of the periodic contraction (or collapse) and revival of the plasma sheath. The observed oscillation frequencies (3.6-13 kHz) are consistent with the transit time of ions across the sheath. Integration of a microplasma device with a transmission electron microscope has also been realized recently (Tai et al 2013 Sci. Rep. 3 1325). This diagnostic tool allows plasma-surface interactions to be observed in real-time with a spatial resolution <100 nm. Although initial experiments concerned the growth of Au islands in a dc plasma, the extension of this probe to nanostructured and spatially modulated surfaces is proposed.

Houlahan, T. J., Jr.; Li, B.; Xu, Z.; Jiang, J.; Liu, G. L.; Ruzic, D. N.; Eden, J. G.

2013-11-01

279

Characterization of InAlAs\\/In0.25Ga0.75As0.72Sb0.28\\/InGaAs double heterojunction bipolar transistors  

Microsoft Academic Search

We report on the characterization of InP-based heterojunction bipolar transistors (HBTs) with low turn-on voltage and high current gain by using InGaAsSb as the base layer. The low turn-on voltage of 0.43 V is attributed to the smaller band gap of the In0.25Ga0.75As072Sb0.28 material. High current gain of 74 is observed despite a heavily Be-doped (9.0×1019 cm-3) base is used,

Chao-Min Chang; Shu-Han Chen; Sheng-Yu Wang; Jen-Inn Chyi

2010-01-01

280

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.

281

Metamorphic materials for indium arsenide transistors  

Microsoft Academic Search

To improve on both the high frequency and low-power aspects of the III-V semiconductor microwave transistor (by definition, the microwave transistor operates at frequencies above 1 GHz), InAs or a related high indium content alloy is incorporated in the base layer of the heterojunction bipolar transistor (HBT) and the channel layer of the high electron mobility transistor (HEMT). These devices

Atif M. Noori

2006-01-01

282

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

283

Evidence of a thermally stable carbon-nitrogen deep level in carbon-doped, nitrogen-implanted, GaAs and AIGaAs  

NASA Astrophysics Data System (ADS)

Nitrogen ion implantation is shown to form high resistivity regions (ps ? 1 × 1010 ?/) in C-doped GaAs and Al0.35Ga0.65As that remains compensated after a 900°C anneal. This is in contrast to oxygen or fluorine implantation in C-doped GaAs which both recover the initial conductivity after a sufficiently high temperature anneal (800°C for F and 900°C for O). In C-doped Al0.35Ga0.65As N- and O-implant isolation is thermally stable but F-implanted samples regain the initial conductivity after a 700°C anneal. A dose dependence is observed for the formation of thermally stable N-implant compensation for both the GaAs and AIGaAs samples. A C-N complex is suggested as the source of the compensating defect level for the N-implanted samples. Sheet resistance data vs anneal temperature and estimates of the depth of the defect levels are reported. This result will have application to heterojunction bipolar transistors and complementary heterostructure field effect transistor technologies that employ C-doped AIGaAs or GaAs layers along with high temperature post-implant isolation processing.

Zolper, J. C.; Sherwin, M. E.; Baca, A. G.; Schneider, R. P.

1995-01-01

284

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

Microsoft Academic Search

A number of up-to-date applications, including advanced optical radars with high single-shot resolution, precise 3 D imaging, laser tomography, time imaging spectroscopy, etc., require low-cost, compact, reliable sources enabling the generation of high-power (1-100 W) single optical pulses in the picosecond range. The well-known technique of using the gain-switching operation mode of laser diodes to generate single picosecond pulses in

Sergey Vainshtein; Juha Kostamovaara

2006-01-01

285

Electronic properties of a one-dimensional channel field effect transistor formed by molecular beam epitaxial regrowth on patterned GaAs  

Microsoft Academic Search

A high mobility electron gas was grown by molecular beam epitaxy on patterned GaAs consisting of a p-GaAs\\/n-GaAs multilayered structure. By contacting to the p-GaAs and n-GaAs layers separately and applying the appropriate bias voltages, we were able to laterally modulate the electron gas to form narrow conduction channels. At 1.5 K we obtain an electron mobility of 5×105 cm2\\/V

J. H. Burroughes; M. L. Leadbeater; M. P. Grimshaw; R. J. Evans; D. A. Ritchie; G. A. C. Jones; M. Pepper

1993-01-01

286

GaAs/Al(0.3)Ga(0.7)As, Heterojunction Bipolar Transistors for High-Temperature (T > 300 deg 0 C), Power Electronic Applications.  

National Technical Information Service (NTIS)

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 p...

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

1987-01-01

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

The bipolar inversion channel field-effect transistor (BICFET) - A new field-effect solid-state device: Theory and structures  

Microsoft Academic Search

The physical structure, operation, and characteristics of a new heterojunction bipolar device in which a source in contact with an inversion channel replaces the conventional base, and a metal emitter replaces the conventional semiconductor emitter, are discussed. The device has potentially very high current gain (10 to the 5th), very high current operation (10 to the 6th A\\/sq cm) and

G. W. Taylor; J. G. Simmons

1985-01-01

289

Realisation et Linearisation d'un Amplificateur de Puissance Hyperfrequence a Transistors Bipolaires Polarises en Classe C (Realization and Linearization of a Hyperfrequency Power Amplifier Implemented with Bipolar Transistors in Class C Polarization).  

National Technical Information Service (NTIS)

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...

Y. Durand

1985-01-01

290

Microwave performance of an optically controlled AlGaAs/GaAs high electron mobility transistor and GaAs MESFET  

NASA Technical Reports Server (NTRS)

Direct current and also the microwave characteristics of optically illuminated AlGaAs/GaAs HEMT are experimentally measured for the first time and compared with that of GaAs MESFET. The results showed that the average increase in the gain is 2.89 dB under 1.7 mW optical intensity at 0.83 microns. Further, the effect of illumination on S-parameters is more pronounced when the devices are biased close to pinch off. Novel applications of optically illuminated HEMT as a variable gain amplifier, high speed high frequency photodetector, and mixer are demonstrated.

Simons, Rainee N.

1987-01-01

291

Carbon doping in molecular beam epitaxy of GaAs from a heated graphite filament  

NASA Technical Reports Server (NTRS)

Carbon doping of GaAs grown by molecular beam epitaxy has been obtained for the first time by use of a heated graphite filament. Controlled carbon acceptor concentrations over the range of 10 to the 17th-10 to the 20th/cu cm were achieved by resistively heating a graphite filament with a direct current power supply. Capacitance-voltage, p/n junction and secondary-ion mass spectrometry measurements indicate that there is negligible diffusion of carbon during growth and with postgrowth rapid thermal annealing. Carbon was used for p-type doping in the base of Npn AlGaAs/GaAs heterojunction bipolar transistors. Current gains greater than 100 and near-ideal emitter heterojunctions were obtained in transistors with a carbon base doping of 1 x 10 to the 19th/cu cm. These preliminary results indicate that carbon doping from a solid graphite source may be an attractive substitute for beryllium, which is known to have a relatively high diffusion coefficient in GaAs.

Malik, R. J.; Nottenberg, R. N.; Schubert, E. F.; Walker, J. F.; Ryan, R. W.

1988-01-01

292

Passivation Effects of 100 nm In0.4AlAs/In0.35GaAs Metamorphic High-Electron-Mobility Transistors with a Silicon Nitride Layer by Remote Plasma-Enhanced Chemical Vapor Deposition  

NASA Astrophysics Data System (ADS)

In0.4AlAs/In0.35GaAs metamorphic high-electron-mobility transistors (MHEMTs) have been successfully fabricated. In order to reduce the surface effects on the barrier layer, Si3N4 layer passivation by remote plasma-enhanced chemical vapor deposition (PECVD) is utilized, which might suppress the surface trap density in side-recessed region and reduce the parasitic resistance. The device simulation was performed to derive the effects of surface trap in the side-recessed region. As the surface trap density decreases, ID.max increases because of the stabilization of the surface states in the side-recessed region. This result indicates that the increases of gm.max and ID.max are related with both the reduction of parasitic resistance and the gate-sinking effect. The fabricated 100 nm MHEMTs with the passivated of Si3N4 layer exhibited excellent characteristics such as a maximum extrinsic gm.max of 740 mS/mm and a cut off frequency ( fT) of 210 GHz.

Kim, Sungwon; Jang, Kyoungchul; Seol, Gyungseon; Her, Jincherl; Seo, Kwangseok

2007-04-01

293

Radiation Tolerance of GaAs Broadband Amplifier.  

National Technical Information Service (NTIS)

The response and degradation characteristics of microstripline GaAs junction field-effect transistor integrated microwave amplifiers were investigated in radiation environments. Permanent changes in electrical performance due to fluences of 5x 10 to the 1...

A. F. Behle R. Zuleeg

1973-01-01

294

Modulation doped GaAs/Al(x)Ga(1-x)As layered structures with applications to field effect transistors  

NASA Astrophysics Data System (ADS)

Traditionally, there have been two approaches to achieving high switchings speeds in semiconductor devices. One is to improve processing and lithographic techniques thereby reducing device dimensions and reducing parasitic losses. The other is to fabricate devices from material with improved transport properties such as GaAs or InP as opposed to Si. With the advent of epitaxial techniques which can grow thin reproducible heterolayer structures on substrates large enough for LSI and VLSI application, devices which employ conduction band engineering to improve device performance are becoming strong contenders in the race for faster devices. Examples of devices which have been improved by conduction band engineering are heterojunction lasers, heterojunction bipolar transistors junction field effect transistors and metal semiconductor field effect transistor (MESFETS). In the aforementioned structures conduction and valence band discontinuities at the heterojunction are used to confine carriers to the active region of the device and/or reduce parasitic currents. A modulation doped heterostructure (MDH), on the other hand, is employed to actually improve or enhance the transport properties of the majority carriers in the channel of a MESFET. In a modulation doped (Al, Ga)As/GaAs heterostructure only the larger bandgap (Al, Ga)As is doped (n-type).

Morkoc, H.

1985-03-01

295

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

296

Comparison of the passivation effects on self- and non-self-aligned InP/InGaAs/InP double heterostructure bipolar transistors by low-temperature deposited SiNx  

NASA Astrophysics Data System (ADS)

Both the self- and non-self-aligned graded-base InP/InGaAs/InP double heterostructure bipolar transistors (DHBTs) were passivated by room-temperature deposited SiNx. Current gains were found to increase significantly after SiNx passivation. The passivation resulted in an increase in the leakage current of base-collector junction. The larger leakage current in the non-self-aligned DHBT made the sudden increase of the collector current in the common-emitter I-V curve occur at smaller collector-emitter bias than that in the self-aligned DHBT, which has smaller leakage current. Further increase in the current gain was found after the DHBTs were exposed to air for 200 days. The leakage current in the base-collector diode was reduced. The sudden increase of the collector current in the non-self-aligned DHBT in the common-emitter I-V characteristics was also suppressed. Investigation of reverse Gummel plots showed that the surface recombination in the base-collector diode was suppressed by the passivation. The leakage current in the base-collector diode was attributed to the increase of the generation rate.

Jin, Z.; Prost, W.; Neumann, S.; Tegude, F.-J.

2004-07-01

297

Bipolar Disorder  

MedlinePLUS

... with spouses and family members. Thus, people undergoing treatment for bipolar disorder sometimes benefit from psychotherapy, in which the ... learn to be an active part of the treatment. Parent's Medication Guide to Treating Bipolar Disorder (APA nd AACAP)

298

Bipolar Disorder  

MedlinePLUS

... 8-10 Bipolar disorder also co-occurs with attention deficit hyperactivity disorder (ADHD), which has some symptoms that overlap with bipolar ... levels of testosterone (a male hormone) in teenage girls and lead to polycystic ovary syndrome (PCOS) in ...

299

Bipolar Disorder  

MedlinePLUS

... you have bipolar disorder. Some people who have bipolar disorder don’t want to get treatment. Often, they don’t realize how much it ... give you the best chance at getting helpful treatment. Read about bipolar disorder and tell your family what you learn. ...

300

Rapid thermal anneal in InP, GaAs and GaAs/GaAlAs  

NASA Astrophysics Data System (ADS)

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

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

301

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

302

GaAs optoelectronic neuron arrays  

NASA Technical Reports Server (NTRS)

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

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

1993-01-01

303

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

304

64K dynamic 1\\/N fractional device bipolar memory  

Microsoft Academic Search

This report will cover a 1\\/N fractional device bipolar memory cell - the FET one-device memory cell equivalent - noting that by reversing the orientation of the transistor and capacitor, the density, thin dielectric and polysilicon techniques of FET technology can be combined with the speed of bipolar technology,

J. Selleck; R. Kenyon; D. Gaffney; F. Wiedman; A. Bhattacharyya; P. Mollier

1980-01-01

305

A compact model for multiterminal bipolar devices used in smart power applications  

Microsoft Academic Search

Complex technologies merging low-voltage bipolar devices and vertical current-flow power transistor allow more smart functions at low chip cost but pose problems during the design phase because there is no way to predict the influence of the high-voltage transistor over the control components by using standard bipolar junction transistor (BJT) models. In fact the large inductive load usually present in

N. Speciale; A. Leone; V. Graziano; G. Privitera

1998-01-01

306

Design considerations for FET-gated power transistors  

NASA Technical Reports Server (NTRS)

An FET-bipolar combinational power transistor configuration (tested up to 300 V, 20 A at 100 kHz) is described. The critical parameters for integrating the chips in hybrid form are examined, and an effort to optimize the overall characteristics of the configuration is discussed. Chip considerations are examined with respect to the voltage and current rating of individual chips, the FET surge capability, the choice of triple diffused transistor or epitaxial transistor for the bipolar element, the current tailing effect, and the implementation of the bipolar transistor and an FET as single chip or separate chips. Package considerations are discussed with respect to package material and geometry, surge current capability of bipolar base terminal bonding, and power losses distribution.

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

1983-01-01

307

A nonlinear macromodel of the bipolar integrated circuit operational amplifier for electromagnetic interference analysis  

Microsoft Academic Search

A nonlinear macromodel for the bipolar transistor integrated circuit operational amplifier is derived from the macromodel proposed by Boyle. The nonlinear macromodel contains only two nonlinear transistors in the input stage in a differential amplifier configuration. Parasitic capacitance effects are represented by capacitors placed at the collectors and emitters of the input transistors. The nonlinear macromodel is effective in predicting

G. K. C. Chen

1981-01-01

308

Bipolar Disorder  

MedlinePLUS

... Doctors Treat It? Although there's no cure for bipolar disorder, treatment can help stabilize moods and help the person ... will watch the symptoms closely and offer additional treatment advice if necessary. Living With Bipolar Disorder Teens normally face ups and downs with ...

309

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

310

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

311

Bipolar Disorder  

MedlinePLUS

... org 3803 N. Fairfax Drive, Suite 100, Arlington, Va. 22203 1 What is bipolar disorder? Bipolar disorder is a ... SHEET NAMI • The National Alliance on Mental Illness • 1 (800) 950-NAMI • www.nami.org 3803 N. Fairfax Drive, Suite 100, Arlington, Va. 22203 2 • A long period of feeling hopeless, ...

312

Non-hysteretic punchthrough impact ionization MOS (PIMOS) transistor: Application to abrupt inverter and NDR circuits  

Microsoft Academic Search

The recently proposed PIMOS transistor can offer, by appropriate operation, non-hysteretic abrupt off-on transitions due to impact ionization if the action of its parasitic bipolar transistor is minimized. This work proposes non-hysteretic abrupt inverter circuits based on <10 mV\\/decade room temperature current switching and a tunable negative differential resistance based on punch-through impact ionization MOS transistors (PIMOS) when parasitic bipolar

Vincent Pott; Kirsten E. Moselund; Adrian M. Ionescu

2008-01-01

313

Metamorphic materials for indium arsenide transistors  

NASA Astrophysics Data System (ADS)

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

Noori, Atif M.

314

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

315

Refined Transistor Model For Simulation Of SEU  

NASA Technical Reports Server (NTRS)

Equivalent base resistance added. Theoretical study develops equations for parameters of Gummel-Poon model of bipolar junction transistor: includes saturation current, amplification factors, charging times, knee currents, capacitances, and resistances. Portion of study concerned with base region goes beyond Gummel-Poon analysis to provide more complete understanding of transistor behavior. Extended theory useful in simulation of single-event upset (SEU) caused in logic circuits by cosmic rays or other ionizing radiation.

Zoutendyk, John A.; Benumof, Reuben

1988-01-01

316

Improved breakdown voltage in GaAs MESFETs utilizing surface layers of GaAs grown at a low temperature by MBE  

Microsoft Academic Search

A metal-semiconductor field-effect transistor (MESFET) utilizing surface layers of GaAs grown at a low temperature by MBE (LT GaAs) under the gate electrode has been fabricated. The high trap density of LT GaAs reduces the surface fields of the FET, suppresses gate leakage, and increases the gate-drain breakdown voltage without sacrificing current drive capability. An undoped AlAs layer is incorporated

L.-W. Yin; Y. Hwang; J. H. Lee; R. M. Kolbas; R. J. Trew; U. K. Mishra

1990-01-01

317

Method for double-sided processing of thin film transistors  

DOEpatents

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

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

2008-04-08

318

Self-aligned multilayer dielectric “dummy gate” technology for GaAs HFET fabrication  

Microsoft Academic Search

The main aspects of the technology for GaAs het- erojunction metal-semiconductor field effect transistors fabrication have been demonstrated. The self-aligned tech- nology with multilayer dielectric \\

Vadim S. Arykov; Anastasia M. Gavrilova; Olga A. Dedkova; Valery A. Kagadei

2011-01-01

319

A two-dimensional analytical model for the gate-source and gate-drain capacitances of ion-implanted short-channel GaAs metal-semiconductor-field effect transistor under dark and illuminated conditions  

Microsoft Academic Search

This paper presents an analytical model for the internal capacitances of short-channel ion-implanted GaAs MESFETs under dark and illuminated conditions. The device structure considered in this study is a normally-on self-aligned GaAs MESFET with indium tin oxide (ITO) as the Schottky metal for the gate electrode of the device. The gate area of the device is illuminated by an optical

Shweta Tripathi; S. Jit

2011-01-01

320

Application of the Johnson criteria to graphene transistors  

NASA Astrophysics Data System (ADS)

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

Kelly, M. J.

2013-12-01

321

Impact of strained GaAs spacer between InP emitter and GaAs1-ySby base on structural properties and electrical characteristics of MOCVD-grown InP/GaAs1-ySby/InP DHBTs  

NASA Astrophysics Data System (ADS)

Novel InP/GaAs1-ySby/InP double-heterojunction bipolar transistors (HBTs) with a GaAs spacer between the InP emitter and GaAs1-ySby base layer were grown by the metalorganic chemical vapor deposition method in order to simplify the switching sequence for forming a high-quality InP-emitter/GaAs1-ySby-base interface. After removal of the InP emitter, the top surface of the GaAs spacer exhibits smooth step-flow-like morphology with root-mean-square roughness of 0.17-0.36 nm, whereas the morphology of the GaAs1-ySby base of the sample without the GaAs spacer is bumpy. Secondary ion mass spectroscopy reveals that the spacer suppresses the incorporation of excess Sb into the InP emitter around the emitter-base junction. The dependence of the current gain on the thickness of the GaAs spacer is investigated and, when the GaAs spacer is 2 nm, the highest current gain is obtained. Therefore, we employ the spacer to scaled-down HBTs with a 0.25-?m-wide emitter. The scaled-down HBTs show high current gain of over 90 at collector current density JC of 10 mA/?m2 even though the space between emitter and base electrodes is just 0.15 ?m. We obtain peak current-gain cut-off frequency of 388 GHz and peak maximum oscillation frequency of 290 GHz at JC=10 mA/?m2. This result suggests that the presence of the GaAs spacer does not impose any penalty on the characteristics at high JC. The insertion of the GaAs spacer is a good way to obtain a high-quality E-B interface with a simple precursor-supply sequence and thereby HBTs with both high-current gain and reasonably high RF performance.

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

2014-06-01

322

Bipolar Disorder  

MedlinePLUS

... might cause your mood changes. If not treated, bipolar disorder can lead to damaged relationships, poor job or school performance, and even suicide. However, there are effective treatments to control symptoms: medicine and talk therapy. A ...

323

Bipolar battery  

DOEpatents

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

Kaun, Thomas D. (New Lenox, IL) [New Lenox, IL

1992-01-01

324

Cryogenic measurements of aerojet GaAs n-JFETs  

NASA Technical Reports Server (NTRS)

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

Goebel, John H.; Weber, Theodore T.

1993-01-01

325

K-band double-balanced mixer using GaAs HBT THz Schottky diodes  

Microsoft Academic Search

We report on a K-band double-balanced mixer using Schottky diodes made with our baseline (Foundry) GaAs HBT technology. The GaAs HBT MBE structure which yields a transistor fmax of 50 GHz, can also support Schottky diode structures with THz cut-off frequencies. A GaAs HBT Schottky diode double-balanced mixer achieves an upconversion loss of less than 6 dB over an RF

K. W. Kobayashi; R. Kasody; A. K. Oki; S. Dow; B. Allen; D. C. Streit

1994-01-01

326

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

National Technical Information Service (NTIS)

This report describes the development of composite ohmic contact and packaging technologies for the wideband gap semiconductor silicon carbide (SiC) with demonstrations of these technologies using 4H-SiC JFETs (junction field effect transistors). The goal...

J. R. Williams R. W. Johnson S. Ryu S. E. Mohney

2006-01-01

327

Space charge limited degradation of bipolar oxides at low electric-fields.  

National Technical Information Service (NTIS)

Radiation-induced degradation of many types of bipolar transistors and circuits is more severe following low dose rate exposure than following high dose rate exposure. Since microelectronic devices in space are generally subjected to low dose rate irradia...

S. C. Witczak R. C. Lacoe D. C. Mayer D. M. Fleetwood R. D. Schrimpf

1998-01-01

328

An ultra high speed ECL-bipolar CMOS technology with silicon fillet self-aligned contacts  

Microsoft Academic Search

An ultra-high-speed half-micron non-overlapped super self-aligned BiCMOS technology that uses a silicon fillet self-aligned contact technology (SIFT) for both bipolar and MOS transistors is discussed. The SIFT process reduces the device capacitances and series resistances by minimizing the diffusion region area as well as the polysilicon electrode area. Deep trench isolation for bipolar transistors allows the device area to be

T. M. Liu; G. M. Chin; M. D. Morris; D. Y. Jeon; V. D. Archer; H. H. Kim; M. Cerullo; K. F. Lee; J. M. Sung; K. Lau; T. Y. Chiu; A. M. Voshchenkov; R. G. Swartz

1992-01-01

329

Response of advanced bipolar processes to ionizing radiation  

SciTech Connect

In this paper ionizing radiation induced gain degradation in microcircuit bipolar polysilicon and crystalline emitter transistors is investigated. In this work, {sup 60}Co 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 degradation occurs at the lowest dose rate complicating hardness assurance testing procedures. The dose rate and anneal data suggest that MIL-STD-883B Test Method 1019.4 is non-conservative for polysilicon emitter transistors, which show enhanced radiation hardness over the crystalline emitter transistors.

Enlow, E.W.; Pease, R.L. (Mission Research Corp., Albuquerque, NM (United States)); Combs, W. (Naval Weapons Support Center, Crane, IN (United States)); Schrimpf, R.D.; Nowlin, R.N. (Arizona Univ., Tucson, AZ (United States). Dept. of Electrical and Computer Engineering)

1991-12-01

330

GaAs/AlGaAs Hereojunction Gate Field Effect Transistor.  

National Technical Information Service (NTIS)

An enhancement mode junction field effect transistor (JFET) using an Al(x)Ga(l-x)As gate and a GaAs channel was designed and fabricated in an attempt to establish a GaAs logic technology base permitting 'direct' coupling without the necessity for level sh...

J. G. Oakes V. L. Wrick R. A. Wickstrom

1978-01-01

331

RBSOA study of high voltage SiC bipolar devices  

Microsoft Academic Search

Rapid improvement of 4H-SiC material quality and maturation of SiC device processing have enabled the development of high voltage SiC bipolar devices for high voltage switching applications. As one of the major concern of bipolar devices, the onset of dynamic avalanche breakdown and reverse biased safe operating area (RBSOA) of SiC pnp and npn transistors have been systematically analyzed in

Jun Wang; Alex Q. Huang; B. Jayant Baliga

2009-01-01

332

Electric-Field Enhancement of a Gate-All-Around Nanowire Thin-Film Transistor Memory  

Microsoft Academic Search

A high-performance gate-all-around (GAA) poly-Si nanowire (NW) SONOS-type memory thin-film transistor (TFT) is presented. The presence of the corners of the GAA structure resulted in the program speed and memory window of this device being superior to those of a planar poly-Si TFT device. When erasing, planar devices exhibit a threshold-voltage shift resulting from gate injection; the GAA device was

Po-Chun Huang; Lu-An Chen; Jeng-Tzong Sheu

2010-01-01

333

A two-dimensional analytical model for the gate-source and gate-drain capacitances of ion-implanted short-channel GaAs metal-semiconductor-field effect transistor under dark and illuminated conditions  

NASA Astrophysics Data System (ADS)

This paper presents an analytical model for the internal capacitances of short-channel ion-implanted GaAs MESFETs under dark and illuminated conditions. The device structure considered in this study is a normally-on self-aligned GaAs MESFET with indium tin oxide (ITO) as the Schottky metal for the gate electrode of the device. The gate area of the device is illuminated by an optical radiation of 0.87 ?m from an external source which is coupled into the device through the semitransparent ITO metal at Schottky-gate to modulate the electrical and microwave characteristics of the device. The nonanalytic Gaussian doping profile commonly considered for the channel doping of an ion-implanted GaAs MESFET has been replaced by an analytic Gaussianlike function for the simplicity of the present model. The two-dimensional (2D) potential distribution obtained by solving the 2D Poisson's equation by including the effect of photo-generated carriers due to the incident optical radiation has been utilized to model the depletion region width below the gate of the short-channel GaAs MESFETs. The depletion width model has then been used to model the internal gate-source and gate-drain capacitances of the device operating under both the linear and saturation regions. The effect of illumination on the Schottky junction at the gate of the MESFET has been modeled by considering an induced photo-voltage developed across the junction that is superimposed on the applied gate bias voltage. The proposed model has been verified by comparing the theoretically predicted results with simulated data obtained by using the commercially available ATLASTM 2D device simulator.

Tripathi, Shweta; Jit, S.

2011-03-01

334

Bipolar Disorder  

Microsoft Academic Search

The 19th-century concept of manic-depressive illness was separated into the distinct syndromes of bipolar disorder (BPD) and\\u000a recurrent major depression in the mid-20th century. BPD is an episodic illness characterized by acute depressive, manic, or\\u000a mixed states of variable frequency, duration and severity, and often with psychotic features, with intervals of full or partial\\u000a recovery. Modern diagnostic systems recognize three

Leonardo Tondo; Matthew J. Albert; Alexia E. Koukopoulos; Christopher Baethge; Ross J. Baldessarini

335

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

336

Types of Bipolar Disorder  

MedlinePLUS

... of episodes of mania and depression. Bipolar I Disorder Bipolar I disorder is characterized by one or more ... like an illness. What is the difference between bipolar disorder and ordinary mood swings? The three main things ...

337

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

338

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

339

High-gain MOS tunnel emitter transistors  

NASA Astrophysics Data System (ADS)

Tunnel emitter transistors (TETs) are promising devices for high-current-density, high-frequency applications. The excellent CMOS compatibility of the TET makes it an ideal candidate to replace the bipolar junction transistors in BiCMOS technology; however, many properties of the TET are still under investigation. In this paper we present TETs with the highest current gain ever reported, 500-800. The effect of oxide quality on device performance is also described, and how the device characteristics can be improved by post-metallization annealing. Finally, we observe enhanced gain due to collector-emitter avalanching.

Aderstedt, Erik; Medugorac, Igor; Lundgren, Per

2002-04-01

340

Degradation mechanisms of current gain in NPN transistors  

Microsoft Academic Search

An investigation of ionization and displacement damage in silicon NPN bipolar junction transistors (BJTs) is presented. The transistors were irradiated separately with 90-keV electrons, 3-MeV protons and 40-MeV Br ions. Key parameters were measured in-situ and the change in current gain of the NPN BJTS was obtained at a fixed collector current (Ic = 1 mA). To characterise the radiation

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

2010-01-01

341

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

SciTech Connect

The results are presented of experimental measurements of the degradation effects of high-energy particle (heavy ion (BR) and electron) and Co-60 (gamma-ray) radiation on the current gain of bipolar transistors made from an advanced process.

Zoutendyk, J.A.; Goben, C.A.; Berndt, D.F.

1988-12-01

342

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

Microsoft Academic Search

The results are presented of experimental measurements of the degradation effects of high-energy particle (heavy ion (BR) and electron) and Co-60 (gamma-ray) radiation on the current gain of bipolar transistors made from an advanced process.

J. A. Zoutendyk; C. A. Goben; D. F. Berndt

1988-01-01

343

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

NASA Technical Reports Server (NTRS)

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

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

1988-01-01

344

Bipolar Disorder Among Adults  

MedlinePLUS

... at NIMH News About Us Home > Health & Education Bipolar Disorder Among Adults Bipolar disorder, sometimes referred to as manic-depressive disorder, ... that are experienced by everyone. Additional information about bipolar disorder can be found on NIMH’s bipolar disorder ...

345

Current reversals in p- n- p transistors  

NASA Astrophysics Data System (ADS)

p- n- p silicon bipolar junction transistors (BJTs) have received a greater attention recently in light of the emerging dilemma of performance and power requirements for bipolar VLSI. The current reversal phenomena due to the avalanche breakdown have been the focus of the study of advanced Si p- n- p BJTs in the past. However, a thorough study of current reversals in p- n- p transistors has not been presented yet. In this paper, we study the base and collector current reversals in the inverse mode and their associated physical mechanisms. The collector and base current reversals have been found when the device is operated with or without avalanche effect. Physical mechanisms have been proposed to interpret these phenomena.

Jang, Sheng-Lyang; Liu, Fong-Chin; Wu, Jim-Yat

1992-12-01

346

22 GHz Performance of the Permeable Base Transistors.  

National Technical Information Service (NTIS)

Small-signal and power performance of GaAs permeable base transistors (PBTs) at 22 GHz is reported. A small-signal gain of 14.5 dB was demonstrated over a 1 GHz bandwidth from a device having a 3200 angstroms periodicity base grating and an 8 x 20 microme...

L. J. Kushner M. A. Hollis R. H. Mathews K. B. Nichols C. O. Bozler

1988-01-01

347

Noise characteristics of gallium arsenide field-effect transistors  

Microsoft Academic Search

Small signal and noise characteristics for GaAs field-effect transistors are derived with the saturated drift velocity of the carriers underneath the gate taken into account. The noise contributed by the saturated carriers is nonnegligible and in most cases, exceeds the noise generated by the unsaturated region. Parasitic elements contribute importantly by preventing the full cancellation of the correlated noise of

H. Statz; H. A. Haus; R. A. Pucel

1974-01-01

348

Manufacturing Methods and Technology (MMT) measure for fabrication of silicon transcalent transistor  

NASA Astrophysics Data System (ADS)

The design of a silicon transcalent transistor, its fabrication and its evaluation are detailed. The transcalent transistor, type J15381, is a triple diffused, bipolar NPN silicon transistor assembly mounted in a ruggedized, heat pipe cooled military package with integral fins for forced air cooling. Both high voltage and high current capabilities are achieved in small size, light weight assembly that has a large safe operating area. The test equipment used for the electrical, mechanical and environmental evaluations is described.

Devito, M. F.; Kessler, S. W.; Reed, R. E.; Trout, D. R.

1980-09-01

349

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

350

Optimum noise source impedance determination for GaAs FETs at room and cryogenic temperatures  

Microsoft Academic Search

An analytical technique is developed to determine the optimum noise source impedance for an extrinsic, or packaged, gallium arsenide field-effect transistor (GaAs FET) using only the small-signal s-parameters and the minimum noise figures available from the manufacturer's data sheet. The procedure is then modified to treat the special case of the intrinsic, or chip, GaAs FET as well. The technique

R. CLARK ROBERTSON; TRI T. HA

1987-01-01

351

High-performance millimeter-wave ion-implanted GaAs MESFETs  

Microsoft Academic Search

GaAs MESFETs (metal-epitaxial-semiconductor-field-effect transistors) with ion-implanted active channels have been fabricated on 3-in-diameter GaAs substrates which demonstrate device performance comparable with that of AlGaAs\\/InGaAs pseudomorphic HEMT (high-electron-mobility transistor) devices. Implanted MESFETs with 0.5-?m gate lengths exhibit an extrinsic transconductance of 350 mS\\/mm. From S-parameter measurements, a current-gain cutoff frequency f1 of 48 GHz and a maximum-available-gain cutoff frequency fmax greater

G. W. Wang; M. Feng; C. L. Lau; C. Ito; T. R. Lepkowski

1989-01-01

352

A Heteroepitaxial Perovskite Metal-Base Transistor  

SciTech Connect

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

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

2011-08-11

353

A heteroepitaxial perovskite metal-base transistor  

NASA Astrophysics Data System (ADS)

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

Yajima, Takeaki; Hikita, Yasuyuki; Hwang, Harold Y.

2011-03-01

354

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

355

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

356

GaAs FET amplifiers reach millimeter waves  

NASA Astrophysics Data System (ADS)

The introduction of a GaAs FET transistor amplifier capable of over 20-dB gain at frequencies in the range from 26.5 to 40 GHz promises to provide new possibilities for system designers. The 26.5-to-40-GHz GaAs FET amplifier offers a new, compact alternative to bulky, expensive Gunn diode amplifiers with interstage broadband ferrite isolators or costly TWT amplifiers with MTBFs of only 5,000 to 10,000 hrs. For currently produced GaAs FET devices in the 18-to-26.5-GHz range, the MTBF is 20,000 to 40,000 hrs. The reliability of GaAs is expected to show itself at frequencies above 26.5 GHz. The Gunn diode, TWT, and GaAs FET amplifiers are compared in a table. The 26.5-to-40-GHz amplifier presently under development is designed with cascadable MIC modules. Low-noise 40GHz GaAs FET amplifiers are suitable as receiving preamplifiers which can be directly mounted on compact antennas, thereby increasing the effectiveness of monopulse direction-finding systems.

Rosenberg, J. C.; Policky, G. J.; Osbrinke, N. K.

1982-06-01

357

Waveform Analysis of GaAs FET Breakdown  

Microsoft Academic Search

drain-gate breakdown of GaAs metal-semiconductor field-effect transistors analyzed using high frequency waveform probing. Peak drain-gate voltage was theoretically and experimentally found to be a determining breakdown factor. The impact ionization induced conduction component of the gate and drain current of pinched-off MESFET at RF was found to correspond to the dc breakdown currents. The transit time of 30 ps was

Y. A. Tkachenko; J. W. Bao; C. J. Wei; J. C. M. Hwang

1995-01-01

358

Bipolar Microprocessor Circuits.  

National Technical Information Service (NTIS)

Partial results of a study to develop bipolar microprocessor devices as well as their associated cross assemblers and simulators are reported. Samples of two MSI peripheral devices were produced and work was started on three bipolar microprocessor devices...

G. Weil

1979-01-01

359

Low and High Frequency Noise Properties of Heterojunction Transistors  

NASA Astrophysics Data System (ADS)

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

Tutt, Marcel Nicholas

1994-01-01

360

GaAs HEMT as sensitive strain gauge  

NASA Astrophysics Data System (ADS)

A strong piezoresistive effect of GaAs micro-structure which is based on high electron mobility transistor (HEMT) is reported in this paper. The GaAs HEMT is embedded in the root of the cantilever as the sensitive element in order to detect the deformation. The strain is simulated with the ANSYS software, and the maximum gauge factor is about 26,350, which is nearly a hundred times larger than that of piezoresistive silicon. The high gauge factor is not only due to the option of voltage bias, but also the combination of the piezoresistive and piezoelectric effect. The obtained results demonstrate that GaAs micro-structure based on HEMT can be suitable for high sensitive stress/pressure sensors.

Liu, Jun; Hou, Tingting; Xue, Chenyang; Tan, Zhenxin; Liu, Guowen; Zhang, Binzhen; Zhang, Wendong

2011-07-01

361

Cryogenic Low Noise Amplifier with GaAs JFETs  

NASA Astrophysics Data System (ADS)

A SONY n-type GaAs junction field effect transistor (JFET) can operate at deep cryogenic temperatures without exhibiting kink phenomena or hysteresis in its I-V characteristics. Further the GaAs JFET has small gate leakage currents(<4.6×10-19A) and a minute input capacitance (0.037 pF). Moreover, even though the gate terminal of a JFET is surrounded by high-impedance materials, the noise level does not increase and a low noise level of ~500 nV/Hz1/2 at 1 Hz with low power dissipation (<1 ?W) was achieved. We are currently developing operational amplifiers (Op-Amps) and digital modules for cryogenically cooled high-sensitivity photodetection systems. The GaAs Op-Amp with an open loop gain of 2000 at a power dissipation of 6.5 ?W has been developed.

Fujiwara, Mikio; Nagata, Hirohisa; Hibi, Yasunori; Matsuo, Hiroshi; Sasaki, Masahide

2009-12-01

362

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

363

Effect of 50 MeV Li3+ ion irradiation on electrical characteristics of high speed NPN power transistor  

Microsoft Academic Search

Silicon NPN overlay RF power high speed commercial bipolar junction transistors (BJTs) find applications in military, space and communication equipments. Here we report the effect of 50 MeV Li3+ ion irradiation in the fluence range 1 × 1011 1.8 × 1012 ions cm-2 on NPN power transistor. The range (R), electronic energy loss (Se), nuclear energy loss (Sn), total ionizing

C. M. Dinesh; Ramani; M. C. Radhakrishna; R. N. Dutt; S. A. Khan; D. Kanjilal

2008-01-01

364

Analysis and Design of a Gated Envelope Feedback Technique for Automatic Hardware Reconfiguration of RFIC Power Amplifiers, with Full On-Chip Implementation in Gallium Arsenide Heterojunction Bipolar Transistor Technology  

NASA Astrophysics Data System (ADS)

In this doctoral dissertation, the author presents the theoretical foundation, the analysis and design of analog and RF circuits, the chip level implementation, and the experimental validation pertaining to a new radio frequency integrated circuit (RFIC) power amplifier (PA) architecture that is intended for wireless portable transceivers. A method called Gated Envelope Feedback is proposed to allow the automatic hardware reconfiguration of a stand-alone RFIC PA in multiple states for power efficiency improvement purposes. The method uses self-operating and fully integrated circuitry comprising RF power detection, switching and sequential logic, and RF envelope feedback in conjunction with a hardware gating function for triggering and activating current reduction mechanisms as a function of the transmitted RF power level. Because of the critical role that RFIC PA components occupy in modern wireless transceivers, and given the major impact that these components have on the overall RF performances and energy consumption in wireless transceivers, very significant benefits stem from the underlying innovations. The method has been validated through the successful design of a 1.88GHz COMA RFIC PA with automatic hardware reconfiguration capability, using an industry renowned state-of-the-art GaAs HBT semiconductor process developed and owned by Skyworks Solutions, Inc., USA. The circuit techniques that have enabled the successful and full on-chip embodiment of the technique are analyzed in details. The IC implementation is discussed, and experimental results showing significant current reduction upon automatic hardware reconfiguration, gain regulation performances, and compliance with the stringent linearity requirements for COMA transmission demonstrate that the gated envelope feedback method is a viable and promising approach to automatic hardware reconfiguration of RFIC PA's for current reduction purposes. Moreover, in regard to on-chip integration of advanced PA control functions, it is demonstrated that the method is better positioning GaAs HBT technologies, which are known to offer very competitive RF performances but inherently have limited integration capabilities. Finally, an analytical approach for the evaluation of inter-modulation distortion (IMD) in envelope feedback architectures is introduced, and the proposed design equations and methodology for IMD analysis may prove very helpful for theoretical analyses, for simulation tasks, and for experimental work.

Constantin, Nicolas Gerard David

365

Turn-on spread determines the size of the switching region in an avalanche transistor  

NASA Astrophysics Data System (ADS)

It has been shown recently that only a small part of the emitter-base interface in a Si bipolar junction transistor participates in short-pulsing avalanche switching. This lateral current shrinkage attributed to the ``winner takes all'' effect reduces the transistor switching size from 1600 to ~100 ?m, still remaining much larger than the transistor structure thickness. We show using quasi-3-D transient modelling that the size of the operating perimeter, which is critically important for switching efficiency and device reliability, is determined by competition between lateral turn-on shrinkage and spread. The latter has never been demonstrated in avalanche transistors before.

Duan, Guoyong; Vainshtein, Sergey; Kostamovaara, Juha

2012-05-01

366

Geriatric bipolar disorder.  

PubMed

Because the elderly are the fastest growing segment of the population, the number of older adults with bipolar disorder is increasing. Geriatric bipolar disorder is relatively rare, with an estimated lifetime prevalence of 0.5% to 1%, although approximately 4% to 17% of older patients in clinical psychiatric settings have bipolar disorder. Bipolar elders are disproportionately affected by medical burden. Given the complex nature of this disorder, comorbidity, and behavioral disturbances, various interventions may be indicated, including pharmacotherapies, electroconvulsive therapy, psychotherapies, and integrated care models. Additional research is needed to better understand the epidemiology, phenomenology, and treatment of geriatric bipolar disorder. PMID:21536161

Sajatovic, Martha; Chen, Peijun

2011-06-01

367

A 30 nm gate-all-around poly-Si nano wire thin-film transistor  

Microsoft Academic Search

In this work, gate-all-around (GAA) poly-Si nano wire (NW) thin film transistors (TFTs) with record physical gate length of 30 nm and driving current >100 ?A\\/?m are demonstrated. The cross section of the NW channel is as small as 35 nm × 8 nm. The tight GAA and NW structure enhances the gate potential control ability effectively, therefore, excellent short

Chen-Ming Lee; Bing-Yue Tsui

2010-01-01

368

A high speed super self-aligned bipolar-CMOS technology  

Microsoft Academic Search

An ideal device structure for integrating bipolar and CMOS is reported in this paper. Both the vertical npn and MOS devices have new non-overlapping super self-aligned structures. With a single 5V supply, averaged per stage delay of 82ps and 125ps have been measured for 0.6µm and 0.85µm (Leff) CMOS ring oscillators. Bipolar transistors have also been fabricated with a nominal

T. Chiu; G. M. Chin; M. Y. Lau; R. C. Hanson; M. D. Morris; K. F. Lee; A. M. Voshchenkov; R. G. Swartz; V. D. Archer; S. N. Finegan

1987-01-01

369

Radiation damage study of a fast bipolar monolithic charge sensitive preamplifier  

Microsoft Academic Search

A fast bipolar monolithic Charge Sensitive Preamplifier (CSP) implemented in the monolithic 2 ?m BiCMOS technology (called HF2CMOS), was studied after neutron irradiation at fluences between 1.26 × 1012 and 1.09 × 1014 n\\/cm2. Neutron fluence effects on the base spreading resistance, rbb?, and the parallel noise of the bipolar npn input device and on the PMOS transistor in the

A. Baschirotto; R. Castello; A. Gola; C. Onado; G. Pessina; P. G. Rancoita; M. Redaelli; A. Seidman

1996-01-01

370

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

371

An NPN 30 GHz, PNP 32 GHz fT complementary bipolar technology  

Microsoft Academic Search

Fully symmetrical complementary bipolar transistors for low power-dissipation and ultra-high-speed LSIs have been integrated in the same chip using a 0.3-?m SPOTEC process. Reducing the surface concentration of the boron by oxidation at the surface of boron diffusion layer suppressed upward diffusion of boron in the subcollector of the pnp transistor during epitaxial growth. This enabled thin epitaxial layer growth

T. Onai; E. Ohue; Y. Idei; M. Tanabe; H. Shimamoto; K. Washio; T. Nakamura

1993-01-01

372

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

NASA Technical Reports Server (NTRS)

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

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

1984-01-01

373

Supergain transistors on high-purity float-zone silicon substrate  

NASA Astrophysics Data System (ADS)

Since float-zone (FZ) silicon has lower contamination and longer minority carrier lifetime than those in Czochralski silicon and other semiconductor materials, it has potential advantages to fabricate a bipolar junction transistor on the FZ substrate to achieve high gain at very low current levels. In this report, the authors present preliminary experimental results on supergain bipolar junction transistors fabricated on unusual FZ refined high-resistivity silicon substrate and by ion implantation technology. A phosphorus-doped polycrystalline silicon backside gettering layer has been employed to preserve the long carrier lifetime of the high-purity FZ silicon. Bipolar junction transistors have demonstrated high current gain, more than 3300 for ultralow base current levels of 10 pA in this study. Possible applications of high-purity FZ silicon on some advanced semiconductor devices and circuits are discussed in this letter.

Han, D. J.; Batignani, G.; Guerra, A. Del.

2003-08-01

374

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

375

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

Microsoft Academic Search

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

M. Ito; O. Wada

1986-01-01

376

Transport characterization of GaAs quantum dots connected with quantum wires fabricated by selective area metalorganic vapor phase epitaxy  

Microsoft Academic Search

We fabricated novel quantum nanostructures where the quantum dots are connected with quantum wires using metalorganic vapor phase epitaxy (MOVPE) on (001) GaAs masked substrates. In particular a GaAs single electron transistor was successfully fabricated and its transport properties were investigated. We prepared two devices which have artificially designed two- or three-prominences in the channel region. These prominences produced a

K. Kumakura; J. Motohisa; T. Fukui

1998-01-01

377

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

378

Bipolar disorder in youth  

Microsoft Academic Search

The debate regarding the possible existence of prepubertal bipolar illness has surfaced at various points in history. In its\\u000a most recent incarnation, proponents of a childhood bipolar diagnosis argue that there is an early-onset form of bipolar illness\\u000a that is highly comorbid and characterized by simultaneous irritability and depression. Others have suggested that childhood\\u000a manic symptoms are more likely a

Gabrielle A. Carlson; Stephanie E. Meyer

2000-01-01

379

Suicide and bipolar disorder  

Microsoft Academic Search

Bipolar disorders are common illnesses with markedly elevated premature mortality, but they remain frequently under-referred,\\u000a under-diagnosed, and under-treated. Suicide is the cause of death in up to 15% of patients with bipolar disorders, and about\\u000a half of them make at least one suicide attempt in their lifetime. The suicide rate of (untreated) bipolar patients is 25 times\\u000a higher than the

Zoltįn Rihmer

380

1\\/f noise and RTS in advanced bipolar technologies  

Microsoft Academic Search

The low frequency noise observed on advanced junction bipolar transistors consist of 1\\/f noise as well as Random telegraph Signals (RTS). In relatively small emitter-base junction areas, RTS is seen in the spectra which can be differentiated from the typical generation-recombination (gr) noise through time domain analysis. For most cases, the 1\\/f noise can be modeled primarily with a current

Zeynep Celik-Butler; Enhai Zhao; Darby Lan; Doug Weiser; Joe Trogolo; Keith Green

2003-01-01

381

A silicon nanocrystal tunnel field effect transistor  

NASA Astrophysics Data System (ADS)

In this work, we demonstrate a silicon nanocrystal Field Effect Transistor (ncFET). Its operation is similar to that of a Tunnelling Field Effect Transistor (TFET) with two barriers in series. The tunnelling barriers are fabricated in very thin silicon dioxide and the channel in intrinsic polycrystalline silicon. The absence of doping eliminates the problem of achieving sharp doping profiles at the junctions, which has proven a challenge for large-scale integration and, in principle, allows scaling down the atomic level. The demonstrated ncFET features a 104 on/off current ratio at room temperature, a low 30 pA/?m leakage current at a 0.5 V bias, an on-state current on a par with typical all-Si TFETs and bipolar operation with high symmetry. Quantum dot transport spectroscopy is used to assess the band structure and energy levels of the silicon island.

Harvey-Collard, Patrick; Drouin, Dominique; Pioro-Ladričre, Michel

2014-05-01

382

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

NASA Astrophysics Data System (ADS)

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

Kim, Hyun-Tak

2013-10-01

383

Single crystal emitter gap for epitaxial Si and SiGe-base transistors  

Microsoft Academic Search

An epitaxial base bipolar technology has been used for fabrication of graded SiGe-based HBTs (heterojunction bipolar transistors) or Si-base pseudo-HBTs with a self-aligned in-situ doped n-type low-temperature epitaxial (LTE) emitter. The thin LTE emitter provides an EB junction with low tunneling current and low capacitance in a n+ poly\\/n\\/p+\\/n thin base HBT design with very high base doping. The authors

J. H. Comfort; E. F. Crabbe; J. D. Cressler; W. Lee; J. Y.-C. Sun; J. Malinowski; M. D'Agostino; J. N. Burghartz; J. M. C. Stork; B. S. Meyerson

1991-01-01

384

A Transistorized Digital Computer.  

National Technical Information Service (NTIS)

The M-54 general-purpose transistorized digital computer is described. This computer is a modification of one of the first transistorized computer models developed at the Moscow 'Order of Lenin' Power Engineering Institute. This single-address machine is ...

I. A. Bashmakov V. S. Zubov V. A. Fedin T. I. Golubeva T. K. Rybakova

1968-01-01

385

Thermal stability and barrier height enhancement for refractory metal nitride contacts on GaAs  

SciTech Connect

Self-aligned GaAs metal-semiconductor field-effect transistor process requires a very thermally stable gate material which must maintain good Schottky contact with GaAs after high-temperature annealing. The electrical characteristics of rf-sputtered ZrN, TiN, and NbN contacts on n-GaAs substrate have been investigated as a function of annealing temperature. We show that all these refractory metal nitride contacts on GaAs have ideality factors very close to unity after annealing at temperatures as high as 850 /sup 0/C. The barrier height for these contacts increases with annealing temperature and very low reverse leakage current is obtained. We also observe similar behavior from previous work on WN/GaAs contacts. Such barrier height enhancement at elevated temperatures has been attributed to the incorporation of nitrogen into GaAs near the metal/GaAs interface.

Zhang, L.C.; Cheung, S.K.; Liang, C.L.; Cheung, N.W.

1987-02-23

386

Bipolar radiofrequency for adenoidectomy  

Microsoft Academic Search

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

J. Mark Palmer

2006-01-01

387

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

388

Differential features between bipolar I and bipolar II disorder  

Microsoft Academic Search

Although bipolar 11 disorder is generally viewed as a mild form of classic manic-depressive illness, recent investigations suggest that it could be a valid diagnostic category different from bipolar I in genetic, biological, clinical, and pharmacological aspects. Twenty-two patients fulfilling Research Diagnostic Criteria for the diagnosis of bipolar II disorder and 38 bipolar I patients were evaluated with the Schedule

E Vieta; C Gastó; A Otero; E Nieto; J Vallejo

1997-01-01

389

[Puzzling bipolar disorder].  

PubMed

Despite many advances in making the diagnosis of bipolar disorder, five to twelve years lie between the first affective episode and the introduction of an effective treatment. However, it is estimated that approximately only one-fourth of the patients with bipolar disorder are recognized as such at all. Clinical experience plays an important role in the diagnosis. Manias are often the cause for the first treatment with drugs, but the daily lives of patients with bipolar depression are often clearly more negatively affected. The acute therapy of bipolar depression is more complicated than that of mania and the difficult long-term treatment is always associated with a high suicide risk. A long-term therapy of bipolar disorders is not only meaningful for the prevention of new disease episodes, but also because it has a positive effect on comorbidities. PMID:15968870

Forsthoff, A; Born, C; Grunze, H

2005-05-17

390

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

391

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

Microsoft Academic Search

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

Martin Pfost; Hans-Martin Rein; Thomas Holzwarth

1996-01-01

392

Hardness assurance and testing issues for bipolar/BiCMOS devices  

SciTech Connect

The dose-rate dependence of the total-dose response of bipolar transistors is mapped for several dose rates. comparisons are made between the total-dose response in x-ray and [sup 60]Co irradiations. Implications for hardness assurance are discussed.

Nowlin, R.N.; Schrimpf, R.D. (Arizona Univ., Tucson, AZ (United States). Dept. of Electrical and Computer Engineering); Fleetwood, D.M. (Sandia National Labs., Albuquerque, NM (United States)); Pease, R.L. (Mission Research Corp., Albuquerque, NM (United States)); Combs, W.E. (Naval Surface Warfare Center, Crane, IN (United States))

1993-01-01

393

Characteristics of High-Speed Silicon Carbide (Sic) Power Transistors  

Microsoft Academic Search

This paper describes the temperature and operating characteristics of NPN 4H-SiC (a polytype of silicon carbide) bipolar junction transistor (BJT) and 4H-SIC Darlington pairs. A large amount of experimental data was collected. The wafer BJTs were able to block over the rated 600 V in the common-emitter configuration and the TO-220 BJTs were able to block over the 1200 V

J. A. Asumadu; J. D. Scofield

2007-01-01

394

Ionization damage in NPN transistors caused by lower energy electrons  

Microsoft Academic Search

Electrical degradation of two type NPN bipolar junction transistors (BJTs) with different emitter sizes was examined under exposures of 70 and 110keV electrons. Base and collector currents as a function of base–emitter voltage were in-situ measured during exposure. Experimental results show that both the 70 and 110keV electrons produce an evident ionization damage to the NPN BJTs. With increasing fluence,

Xingji Li; Jingdong Xiao; Chaoming Liu; Zhiming Zhao; Hongbin Geng; Mujie Lan; Dezhuang Yang; Shiyu He

2010-01-01

395

Bipolar Disorder in Children  

PubMed Central

Although bipolar disorder historically was thought to only occur rarely in children and adolescents, there has been a significant increase in children and adolescents who are receiving this diagnosis more recently (Carlson, 2005). Nonetheless, the applicability of the current bipolar disorder diagnostic criteria for children, particularly preschool children, remains unclear, even though much work has been focused on this area. As a result, more work needs to be done to further the understanding of bipolar symptoms in children. It is hoped that this paper can assist psychologists and other health service providers in gleaning a snapshot of the literature in this area so that they can gain an understanding of the diagnostic criteria and other behaviors that may be relevant and be informed about potential approaches for assessment and treatment with children who meet bipolar disorder criteria. First, the history of bipolar symptoms and current diagnostic criteria will be discussed. Next, assessment strategies that may prove helpful for identifying bipolar disorder will be discussed. Then, treatments that may have relevance to children and their families will be discussed. Finally, conclusions regarding work with children who may have a bipolar disorder diagnosis will be offered.

2014-01-01

396

Subthreshold Degradation of Gate-all-Around Silicon Nanowire Field-Effect Transistors: Effect of Interface Trap Charge  

Microsoft Academic Search

We measured and analyzed the subthreshold degra- dation of the gate-all-around (GAA) silicon nanowire field-effect transistors with the length of 300\\/500 nm and the radius of 5 nm. An analytical model incorporating the effect of interface traps quantitatively explained the measured subthreshold swing (SS) degradation. A simple electrostatic argument showed that the GAA device had smaller degradation of SS values

B. H. Hong; N. Cho; S. J. Lee; Y. S. Yu; L. Choi; Y. C. Jung; K. H. Cho; K. H. Yeo; D.-W. Kim; G. Y. Jin; K. S. Oh; S.-H. Song; J.-S. Rieh; S. W. Hwang

2011-01-01

397

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

NASA Technical Reports Server (NTRS)

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

Zoutendyk, John A. (inventor)

1991-01-01

398

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

NASA Astrophysics Data System (ADS)

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

Zoutendyk, John A.

1991-12-01

399

High-performance millimeter-wave ion-implanted GaAs MESFET's  

Microsoft Academic Search

GaAs MESFETs with ion-implanted active channels have been fabricated on 3-inch-diameter GaAs substrates; the MESFETs demonstrate device performance comparable with that of AlGaAs\\/InGaAs pseudomorphic HEMT (high-electron-mobility transistor) devices. Implanted MESFETs with 500-nm gate lengths exhibit an extrinsic transconductance of 350 mS\\/mm. From S-parameter measurements, a current-gain cutoff frequency f(t) of 48 GHz and a maximum-available-gain cutoff frequency f(max) greater than

G. W. Wang; Milton Feng; C. L. Lau; C. Ito; Thomas R. Lepkowski

1989-01-01

400

High-frequency resonant transistor dc-dc converters  

NASA Astrophysics Data System (ADS)

The design of a transistor dc-dc resonant converter operating at 200-300 kHz is presented, and the operation of a 500-W breadboard version is reported. Several configurations of both voltage-input and current-input type are described and illustrated with circuit diagrams and waveforms, and a full-bridge voltage-input resonant inverter using gate turnoff devices is analyzed in detail, using a piecewise linear approach to obtain design curves. The performance of the breadboard voltage-input half bridge using FET power switches is shown in graphs, demonstrating the low switching losses and transistor stresses achieved by lossless-snubber design. It is predicted that similar designs using bipolar transistors or GTOs can attain energy efficiencies greater than 90 percent. Applications to switching power supplies and battery chargers are suggested.

Steigerwald, R. L.

1984-05-01

401

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

Microsoft Academic Search

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

H.-M. Rein; M. Moller

1996-01-01

402

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

403

[Antidepressants in bipolar disorder].  

PubMed

Whereas mania defines the bipolar disorder, depression is the major challenge of treatment. In general, depressions are more frequent, longer, with a major prognostic impact in terms of disability and suicide. How should we treat a patient with bipolar depression? Antidepressants are the treatment of choice for depression, but not in the bipolar disorder. In this context, we have traditionally accepted that antidepressants are effective but they were inducing a significant risk of destabilization of the bipolar disorder, because of the transitions to mania and rapid cycling. Current data reconsider both the two aspects of this risk-benefit ratio. The effectiveness of antidepressants finally seems very limited, especially after the more recent studies with a robust methodology. Manic switches and rapid cycling may not be increased, particularly with new antidepressants and mood stabilizer combinations. The current literature reminds us that these course's modalities are inherent to the disease, with numerous risk factors, and among them, exposure to antidepressants. Who are the bipolar patients who only get the benefits of antidepressant treatment? Research will tell. They are in any case limited. How to navigate in our treatment strategies ? By choosing first drugs that demonstrated efficacy in bipolar depression. When the situation is more complex, "primum non nocere" should lead to support the prescription of the antidepressant in association with mood stabilizer. PMID:22212875

Courtet, P; Samalin, L; Olié, E

2011-12-01

404

A study of the current distribution established in npn epitaxial transistors during current mode second breakdown  

Microsoft Academic Search

Measurements of the delay time between application of power and subsequent entry into thermally sustained second breakdown have been obtained on a variety of epitaxial npnn + bipolar transistors as a function of ambient temperature. These results have been analysed to yield information on the current distribution established during a preceding electronically sustained second, breakdown phase. Other observations are presented that supplement

D. M. DOW; K. I. NUTTALL

1981-01-01

405

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

NASA Technical Reports Server (NTRS)

The proposed dc model for bipolar junction power switching transistors is based on measurements which may be made with standard laboratory equipment. Those nonlinearities which are of importance to power electronics design are emphasized. Measurements procedures are discussed in detail. A model formulation adapted for use with a computer program is presented, and a comparison between actual and computer-generated results is made.

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

1979-01-01

406

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

NASA Technical Reports Server (NTRS)

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

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

1979-01-01

407

Crossed Andreev Reflection in a Graphene Bipolar Transistor  

Microsoft Academic Search

We investigate the crossed Andreev reflections between two graphene leads connected by a narrow superconductor. When the leads are, respectively, of the n and p type, we find that electron elastic cotunneling and local Andreev reflection are both eliminated even in the absence of any valley-isospin or spin polarizations. We further predict oscillations of both diagonal and cross conductances as

J. Cayssol

2008-01-01

408

Measuring, modeling, and minimizing capacitances in heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

We demonstrate methods to separate junction and pad capacitances from on-wafer S-parameter measurements of HBTs with different areas and layouts. The measured junction capacitances are in good agreement with models, indicating that large-area devices are suitable for monitoring vendor epi-wafer doping. Measuring open HBTs does not give the correct pad capacitances. Finally, a capacitance comparison for a variety of layouts shows that bar-devices consistently give smaller base-collector values than multiple dot HBTs.

Anholt, R.; Bozada, C.; Dettmer, R.; Via, D.; Jenkins, T.; Barrette, J.; Ebel, J.; Havasy, C.; Sewell, J.; Quach, T.

1996-07-01

409

Thermal impedances of multi-finger heterojunction bipolar transistors  

NASA Astrophysics Data System (ADS)

Computed thermal impedances of thermally-shunted HBTs with 2 to 4 fingers are compared with measurements, and several different HBT thermal designs are explored. To minimize self heating by adjacent elements, either the thermal shunt must be very thick or a flip-chip sink should be used.

Anholt, R.

1998-05-01

410

Thermal design of fully-isolated bipolar transistors  

Microsoft Academic Search

The impact of layout parameters on the thermal behavior of BJTs with full dielectric isolation is extensively analyzed by measurements and numerical simulations. The influence of the aspect ratio of the emitter stripe as well as the consequences of the device scaling are investigated from a thermal viewpoint. It is shown that the metallization design plays a key role in

S. Russo; L. La Spina; V. d'Alessandro; L. K. Nanver

2008-01-01

411

Crossed Andreev reflection in a graphene bipolar transistor.  

PubMed

We investigate the crossed Andreev reflections between two graphene leads connected by a narrow superconductor. When the leads are, respectively, of the n and p type, we find that electron elastic cotunneling and local Andreev reflection are both eliminated even in the absence of any valley-isospin or spin polarizations. We further predict oscillations of both diagonal and cross conductances as a function of the distance between the graphene-superconductor interfaces. PMID:18518065

Cayssol, J

2008-04-11

412

SiC Power Bipolar Transistors and Thyristors  

Microsoft Academic Search

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

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

413

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

NASA Technical Reports Server (NTRS)

A full bridge dc-dc converter using a zero voltage and zero current switching technique is described. This circuit utilizes the characteristics of the IGBT to achieve power and frequency combinations that are much higher than those previously reported for this device. Experimental results are included for a 1.5 kW, 100 kHz converter with 94 percent efficiency.

Chen, K.; Stuart, T. A.

1990-01-01

414

Hardness-assurance and testing issues for bipolar/BiCMOS devices  

SciTech Connect

Different hardness-assurance tests are often required for advanced bipolar devices than for CMOS devices. In this work, the dose-rate dependence of bipolar current-gain degradation is mapped over a wide range of dose rates for the first time, and it is very different from analogous MOSFET curves. Annealing experiments following irradiation show negligible change in base current at room temperature, but significant recovery at temperatures of 100 C and above. In contrast to what is observed in MOSFET's, irradiation and annealing tests cannot be used to predict the low-dose-rate response of bipolar devices. A comparison of x-ray-induced and [sup 60]Co gamma-ray-induced gain degradation is reported for the first time for bipolar transistors. The role of the emitter bias during irradiation is also examined. Implications for hardening and hardness assurance are discussed.

Nowlin, R.N.; Schrimpf, R.D. (Univ. of Arizona, Tucson (United States). Dept. of ECE); Fleetwood, D.M. (Sandia National Labs., Albuquerque, NM (United States)); Pease, R.L. (RLP Research, Albuquerque, NM (United States)); Combs, W.E. (Naval Surface Warfare Center, Crane, IN (United States))

1993-12-01

415

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

1999-08-01

416

Effect of 50 MeV Li 3+ ion irradiation on electrical characteristics of high speed NPN power transistor  

Microsoft Academic Search

Silicon NPN overlay RF power high speed commercial bipolar junction transistors (BJTs) find applications in military, space and communication equipments. Here we report the effect of 50MeV Li3+ ion irradiation in the fluence range 1×1011–1.8×1012ionscm?2 on NPN power transistor. The range (R), electronic energy loss (Se), nuclear energy loss (Sn), total ionizing dose (TID) and total displacement damage (Dd) in

C. M. Dinesh; Ramani; M. C. Radhakrishna; R. N. Dutt; S. A. Khan; D. Kanjilal

2008-01-01

417

Radiation Effects in Si-NW GAA FET and CMOS Inverter: A TCAD Simulation Study  

Microsoft Academic Search

In this brief, we have analyzed the response of silicon-nanowire (Si-NW) gate-all-around (GAA) field-effect transistor to total ionizing dose (TID) effects and assessed the impact of single-event effects (SEEs) in simple inverter circuit built from such devices. The analysis of radiation effects is carried out with 3-D technology computer-aided design simulations. Reliability of n-channel and p-channel Si-NW MOSFET is investigated

Gaurav Kaushal; S. S. Rathod; Satish Maheshwaram; S. K. Manhas; A. K. Saxena; S. Dasgupta

2012-01-01

418

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

419

A new charge conserving capacitance model for GaAs MESFET's  

Microsoft Academic Search

We present a new charge conserving capacitance model for Gallium-Arsenide (GaAs) metal semiconductor field effect transistors (MESFET's) based on the quasi-static approximation and a proper partitioning of the channel charge between the source and the drain terminals. A total of nine so-called transcapacitances were determined by taking derivatives of the various terminal charges with respect to the voltages at source,

Muhammad Nawaz; Tor A. Fjeldly

1997-01-01

420

Numerical simulation of an ion-implanted GaAs OPFET  

Microsoft Academic Search

A numerical model of an ion-implanted GaAs optical field-effect transistor (OPFET) has been presented. The model is a physics-based one, and overcomes the major limitations of the existing models by considering both the photoconductive effect in the channel and photovoltaic effect at the gate Schottky barrier as well as the channel-substrate barrier. The exact potential profile in the channel and

P. Chakrabarti; M. Madheswaran; N. a. Khan; Anoop Gupta

1998-01-01

421

Clinical challenges of bipolar depression.  

PubMed

The observation that atypical antipsychotic drugs have some role in treating bipolar disorders has revived interest in the management of bipolar disorder. Given the prevalence of and the disability associated with bipolar depression, current medication is inadequate and new research to help patients with this condition is overdue. PMID:17974295

Pandarakalam, James Paul

2007-10-01

422

Bipolar disorder therapeutics: maintenance treatment  

Microsoft Academic Search

Although most of the care received by bipolar patients occurs during the maintenance phase, relatively little empirical data is available to guide long-term treatment decisions. We review literature pertaining to key questions related to use of pharmacotherapy in the maintenance phase of bipolar disorder. The few double-blind trials with a reasonable sample size are restricted to bipolar I patients and

Gary S Sachs; Michael E Thase

2000-01-01

423

Bipolar disorders in Australia  

Microsoft Academic Search

Objective  To estimate the excess costs associated with bipolar disorders in Australia, based on prevalence (using the Mood Disorder\\u000a Questionnaire (MDQ)) and associated excess burden-of-illness costs.\\u000a \\u000a \\u000a \\u000a Methods  Using data from the 2004 South Australian Health Omnibus Survey (HOS), a weighted cross-sectional survey of 3,015 adults,\\u000a excess costs were estimated from health service utilisation.\\u000a \\u000a \\u000a \\u000a Results  There was a 2.5% lifetime prevalence of bipolar disorders,

Laura J. Fisher; Robert D. Goldney; Eleonora Dal Grande; Anne W. Taylor; Graeme Hawthorne

2007-01-01

424

Bipolar battery construction  

NASA Technical Reports Server (NTRS)

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

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

1981-01-01

425

Thermodynamic stability of Ga2O3(Gd2O3)/GaAs interface  

NASA Astrophysics Data System (ADS)

Ga2O3(Gd2O3)/GaAs heterostructures have been annealed up to ~780 °C. Studies using x-ray reflectivity and high-resolution transmission electron microscopy have shown that the samples annealed under ultrahigh vacuum have maintained smooth and abrupt interfaces with the interfacial roughness being less than 0.2 nm. The oxide remains amorphous, an important parameter for device consideration. Current-voltage and capacitance-voltage measurements have shown low leakage currents (10-8-10-9 A/cm2), a high dielectric constant of 15, and a low interfacial density of states (Dit) between gate dielectrics and GaAs. The attainment of a smooth interface between the gate dielectric and GaAs, even after high temperature annealing for activating implanted dopant, is a must to ensure the low (Dit) and to maintain a high carrier mobility in the channel of the metal-oxide-semiconductor field-effect transistor.

Huang, Y. L.; Chang, P.; Yang, Z. K.; Lee, Y. J.; Lee, H. Y.; Liu, H. J.; Kwo, J.; Mannaerts, J. P.; Hong, M.

2005-05-01

426

Ion implantation processing for high-speed GaAs JFETs  

SciTech Connect

GaAs Junction Field Effect Transistors (JFETs) offer a higher gate turn-on voltage, resulting in a better noise margin and reduced power dissipation, than the more widely employed GaAs MESFET. The primary reason the JFET has not been more widely used is the speed penalty associated with the gate/channel junction and corresponding gate length broadening. We present the ion implantation processes used for a self-aligned, all ion-implanted, GaAs JFET that minimizes the speed penalty for the JFET while maintaining the advantageous higher gate turn-on voltage. Process characterization of the p{sub +}-gate implant done with either Mg, Zn, or Cd along with the co-implantation of P is presented. In addition, a novel backside channel confinement technology employing ion-implanted carbon is discussed. Complete JFET device results are reported.

Zolper, J.C.; Baca, A.G.; Sherwin, M.E.; Shul, R.J.

1995-07-01

427

p+-AlInAs/InP Junction FET's (Field-Effect Transistors) by Selective Molecular Beam Epitaxy.  

National Technical Information Service (NTIS)

Indium Phosphide field-effect transistors (FET's) are promising candidates for a variety of microwave and millimeter-wave applications. InP possesses a higher peak electron velocity and a higher thermal conductivity than GaAs as well as being able to with...

J. D. Woodhouse J. P. Donnelly M. J. Manfra R. J. Bailey

1988-01-01

428

Neutron damage equivalence for silicon, silicon dioxide, and GaAs  

NASA Astrophysics Data System (ADS)

Displacement-energy and ionization-energy transfers to Si, SiO2, and GaAs as functions of incident neutron energy were calculated using cross-section data and fine group structure in the NJOY code system. Neutron spectra determinations for several reactor neutron environments were made using activation cross sections and a novel technique with the SAND II code. Measurements of carrier-removal rates in GaAs and of Si transistor gain degradation were made in representative neutron environments. Experimental results are compared to damage ratios predicted with the spectra and NJOY displacement functions. For fission-like spectra, calculated Si damage ratios are in good agreement with those determined with ASTM E722-85 and with measured transistor damage ratios. Significant differences are found between Si NJOY and ASTM E722-85 for 14-MeV-to-reactor neutron damage ratios; NJOY gives better agreement with experimental data reported in the literature. In GaAs, 14-MeV-to-reactor experimental damage ratios are smaller than predicted by calculated displacement ratios. This suggests that a more complex model of damage for majority carrier removal in GaAs is required. The use of incorrect damage functions is shown to adversely affect simulation fidelity in some representative neutron environments.

Luera, Theodore F.; Kelly, John G.; Stein, Herman J.; Lazo, Maximo S.; Lee, Clarence E.

1987-12-01

429

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

430

Bipolar depression: overview and commentary.  

PubMed

Depressive phases are the most prevalent component of bipolar disorders, even with modern treatment. Bipolar depressive morbidity is often misdiagnosed and is limited in response to available treatments. These conditions are especially debilitating and are associated with psychiatric comorbidity, substance abuse, functional disability, and increased mortality owing to early suicide and accidents, and later medical illnesses. There is growing awareness that bipolar depression is one of the greatest challenges in modern psychiatry. It is essential to differentiate various forms of depression, dysthymia, and dysphoric mixed states of bipolar disorders from the clinical features of more common, unipolar major depressive disorders. In bipolar depression, antidepressant responses often are unsatisfactory, and these agents probably are overused. Emerging treatments, including several anticonvulsant and modern antipsychotic drugs, as well as lithium-alone or in selected combinations-are partially effective for bipolar depression. Interest in recognizing bipolar depression and seeking more effective, specific, and safer treatments for it are growing. PMID:20415631

Baldessarini, Ross J; Vieta, Eduard; Calabrese, Joseph R; Tohen, Mauricio; Bowden, Charles L

2010-01-01

431

Pediatric Bipolar Disorder  

PubMed Central

Clinicians are less sensitive in considering the diagnosis of mania in children because of the variations in clinical presentation and because of the high comorbidity with other psychiatric disorders. More often than the elated and expansive mood, irritability and significant aggression may be the presenting symptoms in these cases. One such case report is discussed highlighting the clinical aspects of pediatric bipolar disorder.

Aravind, V. K.; Krishnaram, V. D.

2009-01-01

432

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

433

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

434

Infinite electrical networks and transistor modeling  

NASA Astrophysics Data System (ADS)

The theory and applications of infinite electrical networks are investigated. Methods were devised for computing the currents and voltages in uniform and non-uniform, grounded and ungrounded semi-infinite electrical grids. These results were applied to the numerical simulation of bipolar transistors and to the computational techniques arising in geophysical exploration. A complete and rigorous theory for infinite lumped transmission lines was at last achieved by closing a long-standing lacuna, and this was extended to ladder networks whose parameters are operators on a Hilbert space. A parametric representation for a general class of linear time-varying systems was devised. A new matroid for a certain class of infinite graphs was discovered.

Zemanian, A. H.

1982-09-01

435

Study of improved reverse recovery in power transistor incorporating universal contact  

NASA Astrophysics Data System (ADS)

The improvement in reverse recovery of power NPN bipolar transistor (BJT) through incorporation of "universal contact" in the base is studied in detail. It is shown that use of universal contact allows redistribution of base current in saturation from collector region where recombination lifetime is high to extrinsic base region where effective recombination lifetime is low. The reverse recovery time decreases as collector current density increases but increases as collector breakdown voltage increases. The improvement in reverse recovery is accompanied with an increase in collector-emitter voltage in the ON state. For low voltage transistors and high voltage transistors at low collector current densities, the increase is primarily due to reduction in reverse current gain. For high breakdown voltage transistors, the use of universal contact results in early onset of quasi-saturation effect and results in degradation in ON state voltage at high collector current densities.

Anand, R. S.; Mazhari, B.; Narain, J.

2004-05-01

436

Quantum mechanics prescriptions for compound-semiconductor transistor technologies  

NASA Astrophysics Data System (ADS)

We employ an accurate one-dimensional, self-consistent quantum-mechanical-Poisson solver to derive parameters that enable the Poisson solver to accurately compute charge- or capacitance-voltage curves for use in two-dimensional solvers. We consider metal-oxide-semiconductor field effect transistors (MOSFETs), where we adjust gate work functions and oxide thicknesses and SiGe MOSFETs with spacer layers where we adjust gate work functions and the carrier densities in the spacer layers. For GaAs pHEMTs, InP lattice-matched high electron mobility transistors (HEMTs), SiGe HEMTs, double-heterojunction pHEMTs, AlGaN/GaN HEMTs and delta-doped MESFETs we adjust the Schottky barrier heights to shift pinchoff voltages.

Anholt, R.

2001-07-01

437

Improved carrier injection in gate-all-around Schottky barrier silicon nanowire field-effect transistors  

Microsoft Academic Search

This letter presents the performance improvement of Schottky barrier metal-oxide-semiconductor field-effect transistor by employing gate-all-around (GAA) Si-nanowire (SiNW) structure. Without employing any barrier lowering technique, the mid-band-gap Ni-silicide Schottky barrier transistors demonstrated excellent performance and achieved subthreshold slope of ~86 mV\\/decade and on-current of 19 muA\\/mum on a 12.5 nm SiNW, and subthreshold slope of ~79 mV\\/decade and on-current of

J. W. Peng; S. J. Lee; G. C. Albert Liang; N. Singh; S. Y. Zhu; G. Q. Lo; D. L. Kwong

2008-01-01

438

Improved carrier injection in gate-all-around Schottky barrier silicon nanowire field-effect transistors  

Microsoft Academic Search

This letter presents the performance improvement of Schottky barrier metal-oxide-semiconductor field-effect transistor by employing gate-all-around (GAA) Si-nanowire (SiNW) structure. Without employing any barrier lowering technique, the mid-band-gap Ni-silicide Schottky barrier transistors demonstrated excellent performance and achieved subthreshold slope of ?86 mV\\/decade and on-current of 19 ?A\\/?m on a 12.5 nm SiNW, and subthreshold slope of ?79 mV\\/decade and on-current of

J. W. Peng; S. J. Lee; G. C. Albert Liang; N. Singh; S. Y. Zhu; G. Q. Lo; D. L. Kwong

2008-01-01

439

Soliton Tunneling Transistor  

Microsoft Academic Search

We report on a macroscopic version of the single-electron transistor (SET), which we call the soliton tunneling transistor (STT). The STT, consists of a gate capacitor coupled to a NbSe$_{3}$ crystal with a charge density wave (CDW). The current-voltage characteristic of an STT is periodically modulated by the gate voltage, as in the SET,except that the periodicity corresponds to a

J. H. Miller; Jr; G. Cardenas; A. Garcia; W. More; A. W. Beckwith; J. P. McCarten

2001-01-01

440

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

441

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

442

A comparison of radiation damage in transistors from cobalt-60 gamma rays and 2. 2. MeV electrons  

SciTech Connect

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

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

1982-12-01

443

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

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

444

Total Dose Effects on Single Event Transients in Digital CMOS and Linear Bipolar Circuits  

NASA Technical Reports Server (NTRS)

This presentation discusses the effects of ionizing radiation on single event transients (SETs) in circuits. The exposure of integrated circuits to ionizing radiation changes electrical parameters. The total ionizing dose effect is observed in both complementary metal-oxide-semiconductor (CMOS) and bipolar circuits. In bipolar circuits, transistors exhibit grain degradation, while in CMOS circuits, transistors exhibit threshold voltage shifts. Changes in electrical parameters can cause changes in single event upset(SEU)/SET rates. Depending on the effect, the rates may increase or decrease. Therefore, measures taken for SEU/SET mitigation might work at the beginning of a mission but not at the end following TID exposure. The effect of TID on SET rates should be considered if SETs cannot be tolerated.

Buchner, S.; McMorrow, D.; Sibley, M.; Eaton, P.; Mavis, D.; Dusseau, L.; Roche, N. J-H.; Bernard, M.

2009-01-01

445

n-Type Doping of Vapor-Liquid-Solid Grown GaAs Nanowires  

NASA Astrophysics Data System (ADS)

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

Gutsche, Christoph; Lysov, Andrey; Regolin, Ingo; Blekker, Kai; Prost, Werner; Tegude, Franz-Josef

2011-12-01

446

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) [Los Alamos, NM; Zawodzinski, Christine (Los Alamos, NM) [Los Alamos, NM

2001-01-01

447

[Bipolar disorder in adolescence].  

PubMed

Juvenile mania is a concept widely developed but also highly debated since the 1990s. In the heart of this debate, Severe Mood Dysregulation (SMD) and "Temper Dysregulation disorder with Dysphoria" (recently integrated in DSM-5) showed their interest. Actually, the objective is to distinguish two clinical phenotypes in order to avoid confusion between (1) what would raise more of mood dysregulation with chronic manic like symptoms, and (2) bipolar disorder type I with episodic and acute manic episodes. Therapeutic stakes are major. In adolescents, even if DSM adult diagnostic criteria can be used and bipolar disorder type I clearly established, differential diagnostic at onset between acute manic episode and schizophrenia onset remain sometimes difficult to assess. Furthermore, it is crucial to better assess outcome of these adolescents, in terms of morbidity and potential prognosis factors, knowing that a younger age at onset is associated with a poorer outcome according to several adult studies. Therapeutic implications could then be drawn. PMID:24855784

Brunelle, Julie; Milhet, Vanessa; Consoli, Angčle; Cohen, David

2014-04-01

448

Preventing Simultaneous Conduction In Switching Transistors  

NASA Technical Reports Server (NTRS)

High voltage spikes and electromagnetic interference suppressed. Power-supply circuit including two switching transistors easily modified to prevent simultaneous conduction by both transistors during switching intervals. Diode connected between collector of each transistor and driving circuit for opposite transistor suppresses driving signal to transistor being turned on until transistor being turned off ceases to carry current.

Mclyman, William T.

1990-01-01

449

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

450

Fully bipolar, 120-Msample\\/s 10-b track-and-hold circuit  

Microsoft Academic Search

Describes the design and experimental results of a fully bipolar track-and-hold (T&H) circuit for use in video applications. A fully differential, open-loop approach has been chosen in order to meet the specifications with respect to track-to-hold step, droop rate, and hold-mode feedthrough. In order to obtain maximum high-frequency performance, p-n-p transistors have been omitted from the design. The T&H circuit

P. Vorenkamp; J. P. M. Verdaasdonk

1992-01-01

451

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

452

Modeling low-dose-rate effects in irradiated bipolar-base oxides  

Microsoft Academic Search

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. The additional

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

1998-01-01

453

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

454

Monolithic integration of a GaAlAs buried-heterostructure laser and a bipolar phototransistor  

NASA Technical Reports Server (NTRS)

A GaAlAs buried-heterostructure laser has been monolithically integrated with a bipolar phototransistor. The heterojunction transistor was formed by the regrowth of the burying layers of the laser. Typical threshold current values for the lasers were 30 mA. Common-emitter current gains for the phototransistor of 100-400 and light responsitivity of 75 A/W (for wavelengths of 0.82 micron) at collector current levels of 15 mA were obtained.

Bar-Chaim, N.; Harder, CH.; Margalit, S.; Yariv, A.; Katz, J.; Ury, I.

1982-01-01

455

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

Microsoft Academic Search

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

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

1996-01-01

456

Noise models for gallium arsenide field-effect transistors at room and cryogenic temperatures  

Microsoft Academic Search

An analytical technique is developed to determine the optimum noise source impedance for a chip gallium arsenide field-effect transistor (GaAs FET) using only the small-signal s-parameters and the minimum noise figures available from the manufacturer's data sheet. The technique is then extended to determine the optimum noise source impedance and minimum noise figure at cryogenic temperatures using the room temperature

R. CLARK ROBERTSON; TRI T. HA

1986-01-01

457

Design, fabrication and characterization of dual-channel real space transfer transistor  

Microsoft Academic Search

In this paper, using a ?-doping dual-channel structure and GaAs substrate, a real space transfer transistor (RSTT) is designed\\u000a and fabricated successfully. It has the standard ?-shaped negative resistance I–V characteristics as well as a level and smooth valley region that the conventional RSTT has. The negative resistance parameters\\u000a can be varied by changing gate voltage (V\\u000a GS). For example,

Weilian Guo; Shilin Zhang; Xin Yu

2009-01-01

458

SubMicron Vertical AlGaAs\\/GaAs Resonant Tunneling Single Electron Transistor  

Microsoft Academic Search

We explore vertical transport phenomena in sub-micron asymmetric AlGaAs\\/GaAs double barrier structures (DBS's) by applying a bias to a special Schottky side gate which allows the effective area of the conducting channel to be adjusted or ``tuned''. The AlGaAs barriers are selectively doped to generate excess electrons in the GaAs well, and thus single electron transistor (SET) operation is possible

David Guy Austing; Takashi Honda; Yasuhiro Tokura; Seigo Tarucha

1995-01-01

459

Negative transconductance in a resistive gate metal-semiconductor field-effect transistor  

Microsoft Academic Search

Negative transconductance is reported in a resistive gate metal-semiconductor field-effect transistor (MESFET) for the first time. The negative transconductance arises as a result of the negative differential mobility of electrons in the GaAs channel, and is adequately described by a simple equivalent circuit model. The experimental device is fabricated with a planar ion-implanted MESFET process, and shows promise as a

Y. Yin; J. A. Cooper; P. G. Neudeck; M. L. Balzan; A. E. Geissberger

1989-01-01

460

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

SciTech Connect

The radiation response of npn Bipolar junction transistor (BJT) has been examined for 100 MeV O{sup 7+} ion. Key electrical properties like Gummel characteristics, dc current gain and capacitance-voltage of 100MeV O{sup 7+} ion irradiated transistor were studied before and after irradiation. The device was decapped and the electrical characterizations were performed at room temperature. Base current is observed to be more sensitive than collector current and gain appears to be degraded with ion fluence, also considerable degradation in C-V characteristics is observed and doping concentration is found to be increased along with the increase in ion fluence.

Kumar, M. Vinay; Krishnakumar, K. S.; Dinesh, C. M.; Krishnaveni, S.; Ramani [Department of studies in Physics, University of Mysore, Mysore (India); Department of Physics, APS College, Bengaluru (India); Department of Physics, DCE, Govt. First Grade College, Mangalore (India); Department of studies in Physics, University of Mysore, Mysore (India); Department of Physics, Bangalore University, Bengaluru (India)

2012-06-05

461

Majority carrier type conversion in solution-processed organic transistors and flexible complementary logic circuits  

NASA Astrophysics Data System (ADS)

We report on the realization of high performance solution-processed ambipolar organic transistors based on a quinoidal oligothiophene derivative. The devices show hole and electron field-effect mobilities in air as high as 0.1 and 0.006 cm2 V-1 s-1, respectively, and can be converted from ambipolar p-type dominant to n-type transistors by thermal annealing. The conversion of the majority carrier type is assigned to strong variations in molecular packing. The demonstration of complementary flexible inverters suggests an effective strategy for patterning lateral pn-bipolar structures in solution-processed thin films made from a monolithic ambipolar organic semiconductor.

Ribierre, J. C.; Watanabe, S.; Matsumoto, M.; Muto, T.; Aoyama, T.

2010-02-01

462

Bipolar Disorder - Multiple Languages: MedlinePlus  

MedlinePLUS

... page, please enable JavaScript. Bipolar Disorder - Multiple Languages Russian (???????) Somali (af Soomaali) Spanish (espańol) Russian (???????) Bipolar Disorder English ?????????? ???????????? - ??????? (Russian) ...

463

Tratamento da depressćo bipolar The Treatment of Bipolar Depression  

Microsoft Academic Search

The treatment of bipolar depression has been an area of debate. The use of antidepressants, particularly the triciclics, has been associated with worse clinical outcomes. Evidence points to a limited efficacy of traditional mood stabilizers such as lithium, valproate and carbamazepine in the treatment of bipolar depression. In cases where depression is more severe, there is evidence that antidepressants may

BENY LAFER; MARCIA B RITTO; MACEDO SOARES

2005-01-01

464

Staying well with bipolar disorder  

Microsoft Academic Search

Objective: The research aimed to investigate how people diagnosed with bipolar mood disorder avoided episodes of illness and managed to stay well. The research also examined the role that personal, social and environmental factors played in helping people with bipolar mood disorder to stay well. Method: This project used a combination of qualitative research methods. The design contained three (3)

Sarah J. Russell; Jan L. Browne

2005-01-01

465

Self-aligned multilayer dielectric “dummy gate” technology for L-, S- and X-band GaAs MMICs fabrication  

Microsoft Academic Search

This paper demonstrates the main aspects of the technology for GaAs microwave monolithic integrated circuits fabrication. The self-aligned technology with multilayer dielectric “dummy gate” used for fabrication of the metal-semiconductor field effect transistor with 0.5 microns gate length and ion implantation for channel, drain and source regions formation is described. Methods of front- and backside processing and specifications of control

E. V. Anishchenko; V. S. Arykov; A. M. Gavrilova; O. A. Dedkova; V. A. Kagadei; O. V. Kamchatnaya; Y. V. Lilenko; A. Y. Yushenko

2010-01-01

466

Frequency-dependent characteristics of an ion-implanted GaAs MESFET with opaque gate under illumination  

Microsoft Academic Search

Commercial metal-semiconductor-field-effect transistors (MESFET's) have opaque gate. We present here the frequency-dependent characteristics of an ion-implanted GaAs MESFET with opaque gate under illumination. The incident light enters the device through the gate-source and gate-drain spacings. Two photovoltages are developed: one across the Schottky junction due to generation in the side walls of the depletion layer below the gate and the

Nandita Saha Roy; B. B. Pal; R. U. Khan

2000-01-01

467

GaAs on Ge for CMOS  

Microsoft Academic Search

Selective epitaxial growth of GaAs on Ge is a prerequisite for the integration of GaAs and Ge in the sub-22 nm CMOS nodes. The problems encountered for epitaxial growth of GaAs on Ge are described and illustrated. Mainly the problem of anti-phase boundary (APB) formation is addressed. Selective epitaxial growth of GaAs on Ge with a SiO2 mask is discussed and

G. Brammertz; M. Caymax; M. Meuris; M. Heyns; Y. Mols; S. Degroote; M. Leys

2008-01-01

468

Integration of GaAs epitaxial layer to Si-based substrate using Ge condensation and low-temperature migration enhanced epitaxy techniques  

NASA Astrophysics Data System (ADS)

A GaAs defect-free epitaxial layer has been grown on Si via a Ge concentration graded SiGe on insulator (SGOI) for application in high channel-mobility metal-oxide-semiconductor field effect transistor. The SGOI layer, 42 nm thick, serves as the compliant and intermediate buffer to reduce the lattice and thermal expansion mismatches between Si and GaAs. A modified two-step Ge condensation technique achieves the surface Ge concentration in SGOI as high as 71%. It is also found that low-temperature migration enhanced epitaxy during the initial GaAs nucleation on the SGOI surface is critical to obtain a device quality GaAs layer by epitaxial growth.

Oh, Hoon Jung; Choi, Kyu Jin; Loh, Wei Yip; Htoo, Thwin; Chua, Soo Jin; Cho, Byung Jin

2007-09-01

469

Terahertz responsivity of field effect transistors versus their static channel conductivity and loading effects  

NASA Astrophysics Data System (ADS)

We study the broadband photovoltaic response of field effect transistors on terahertz radiation. A simple physical analytical model of the response is developed. It is based on plasma density perturbation in the transistor channel by the incoming terahertz radiation. The model shows how the non-resonant detection signal is related to static (dc) transistor characteristics. We analyze loading effects related to capacitive, inductive, and resistive coupling of the detector to the read-out circuit as a function of modulation frequencies and loading resistors. As we show, the proposed physical model completed by loading effects fully describes the experimental results on the non-resonant sub-terahertz detection by all studied III-V (GaAs, GaN) and silicon based transistors. Field effect transistors were recently proposed as the best terahertz detecting pixels for fabrication of low cost focal plane arrays for terahertz imaging. This article gives prospects for electrical simulation of these transistors and their optimal integration in the focal plane arrays.

Sakowicz, M.; Lifshits, M. B.; Klimenko, O. A.; Schuster, F.; Coquillat, D.; Teppe, F.; Knap, W.

2011-09-01

470

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

471

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

472

SEMICONDUCTOR INTEGRATED CIRCUITS: An ultra-high-speed direct digital frequency synthesizer implemented in GaAs HBT technology  

NASA Astrophysics Data System (ADS)

This paper presents a 10-GHz 8-bit direct digital synthesizer (DDS) microwave monolithic integrated circuit implemented in 1 ?m GaAs HBT technology. The DDS takes a double-edge-trigger (DET) 8-stage pipeline accumulator with sine-weighted DAC-based ROM-less architecture, which can maximize the utilization ratio of the GaAs HBT's high-speed potential. With an output frequency up to 5 GHz, the DDS gives an average spurious free dynamic range of 23.24 dBc through the first Nyquist band, and consumes 2.4 W of DC power from a single -4.6 V DC supply. Using 1651 GaAs HBT transistors, the total area of the DDS chip is 2.4 × 2.0 mm2.

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

2010-06-01

473

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

474

Managing bipolar depression.  

PubMed

What should the clinician do when confronted with a patient who has depressive symptoms? Seek the proper diagnosis. Question the patient about depressive symptoms over a two-week course that interferes with social and/or occupational functioning. Determine if there is any history of mania or hypomania. Information from a significant other is extremely useful as well. Coexisting diagnoses, such as substance abuse, posttraumatic stress disorder, or medical conditions, must be ruled in or out. It is critical to include a suicide risk assessment in the evaluation. Lithium is still the gold standard for bipolar patients with its suicide preventative effects. Lamotrigine appears to have the advantage of efficacy against bipolar depression without high risk for inducing mania. Experts recommend that a mood stabilizer be used in combination with antidepressants. The tricyclic antidepressants and the monoamine oxidase inhibitors appear to have the highest risk for mania and are best avoided. Atypical antipsychotic medications are best utilized for psychotic symptoms and as adjuncts to existing antidepressants. Cognitive behavioral therapy may complement pharmacotherapy. PMID:21103153

Pary, Raymond; Matuschka, Paul R; Lewis, Susan; Lippmann, Steven

2006-02-01

475

Bipolar pulse forming line  

DOEpatents

A bipolar pulse forming transmission line module for linear induction accelerators having first, second, third, fourth, and fifth planar conductors which form an interleaved stack with dielectric layers between the conductors. Each conductor has a first end, and a second end adjacent an acceleration axis. The first and second planar conductors are connected to each other at the second ends, the fourth and fifth planar conductors are connected to each other at the second ends, and the first and fifth planar conductors are connected to each other at the first ends via a shorting plate adjacent the first ends. The third planar conductor is electrically connectable to a high voltage source, and an internal switch functions to short a high voltage from the first end of the third planar conductor to the first end of the fourth planar conductor to produce a bipolar pulse at the acceleration axis with a zero net time integral. Improved access to the switch is enabled by an aperture through the shorting plate and the proximity of the aperture to the switch.

Rhodes, Mark A. (Pleasanton, CA)

2008-10-21

476

Bipolar coagulation in neurosurgery.  

PubMed

Coagulation is an essential part of a surgical procedure, especially in neurosurgery. Beginning in the early years of this century, various techniques have been used to control bleeding at the surgical site. Over the years, these techniques have led to the invention of the bipolar coagulator and its modifications. Prevention of charring and tissue adhesion have been the goals of bipolar coagulator manufacturers all over the world; new techniques and different metallurgical compositions for the forceps have been tried to achieve these results. The NS2000, with its microprocessor-based controlled coagulative sequence, can be a good system for reducing tissue adhesion and charring under desired limits of low output power ranges provided by the system. Comparable results can also be obtained with the Malis CMC III and Synergy Malis systems with irrigation channels. These systems have the additional advantages of providing higher power outputs at lower panel settings and a maximum power output greater than that of NS2000. For neurosurgeons who need the additional option of cutting, the Malis CMC III is the recommended system. PMID:9508124

Dujovny, M; Dujovny, N; Gundamraj, N R; Misra, M

1998-03-01

477

Neuropsychological performance in pediatric bipolar disorder  

Microsoft Academic Search

BackgroundGrowing awareness of childhood bipolar disorder necessitates further cognitive neuroscience research to determine unique developmental differences between pediatric and adult onset bipolar disorder. We sought to examine whether neuropsychological function in children with bipolar disorder resembles that in adults with the illness and to extend our knowledge about cognitive function in pediatric bipolar disorder.

Daniel P Dickstein; Julia E Treland; Joseph Snow; Erin B McClure; Mona S Mehta; Kenneth E Towbin; Daniel S Pine; Ellen Leibenluft

2004-01-01

478

The Stanley Foundation Bipolar Treatment Outcome Network  

Microsoft Academic Search

Background: Since recent NIMH Bipolar Disorder Workshops highlighted the dearth of longitudinal and controlled studies of bipolar illness, the Stanley Foundation Bipolar Network (SFBN) has recruited a large cohort of patients with bipolar disorder to begin to address these issues. This report describes the demographics and course of illness characteristics of this study population. Methods: The first 261 outpatients to

Trisha Suppes; Gabriele S Leverich; Paul E Keck; Willem A Nolen; Kirk D Denicoff; Lori L Altshuler; Susan L McElroy; A. John Rush; Ralph Kupka; Mark A Frye; Maia Bickel; Robert M Post

2001-01-01

479

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

480

Field effect transistors  

Microsoft Academic Search

A patent is claimed for an invention relating to Metal Insulator Semiconductor Field Effect Transistors (MISFECTs) in which organic polymers are used as the semiconducting component. The FET has a gate electrode deposited on a substrate and separated from a semiconducting layer by an insulating layer, the semiconducting layer being provided with two terminals to allow passage of an electric

Philip Charles Allen; Richard Henry Friend; Jeremy Henly Burroughes

1988-01-01

481

Nanowire transistors without junctions  

Microsoft Academic Search

All existing transistors are based on the use of semiconductor junctions formed by introducing dopant atoms into the semiconductor material. As the distance between junctions in modern devices drops below 10 nm, extraordinarily high doping concentration gradients become necessary. Because of the laws of diffusion and the statistical nature of the distribution of the doping atoms, such junctions represent an

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

2010-01-01

482

Differential diagnosis of unipolar vs bipolar depression.  

PubMed

Bipolar depression is commonly misdiagnosed as unipolar depression, which can be detrimental to the patient. Two effective and valuable screening tools to help accurately diagnose bipolar disorder and differentiate between unipolar depression and bipolar depression are the Mood Disorder Questionnaire and the Composite International Diagnostic Interview. An incorrect or late diagnosis can pose significant consequences because treatment for unipolar depression may actually exacerbate bipolar symptoms. The costs associated with unrecognized bipolar disorder are significantly higher than those for either recognized bipolar disorder or major depressive disorder. Early and accurate diagnosis of bipolar depression is crucial for patients' well-being in regard to interpersonal, financial, and professional aspects of their lives. PMID:25004191

Culpepper, Larry

2014-06-01

483

Effective laser ultrasonic detection with biased GaAs photoelectromotive force detectors  

NASA Astrophysics Data System (ADS)

Improvement of the sensitivity of laser-induced ultrasonic detection by GaAs adaptive photoelectromotive force (photo-EMF) devices under external dc bias is reported. The gain in responsivity of the detector about 7× in ~10 MHz frequency band was observed under application of an external dc field ~50 V/mm at ?=633 nm. Detailed experiments show that this growth is paid by proportional shift of maximum of the photo-EMF response to lower spatial frequencies and by appearance of a relatively broad resonance pick located at modulation frequencies lower than the cutoff frequency of the unbiased GaAs photo-EMF detector. These results are consistently interpreted using a theoretical model of the photo-EMF effect in bipolar photoconductor with large lifetime of one type of the photocarriers.

Castillo, J.; Rodriguez, P.; Aguirre, A.; Stepanov, S.; Mansurova, S.

2002-05-01

484

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

485

A process and device model for GaAs MESFET technology - GATES  

NASA Astrophysics Data System (ADS)

A combined process and device modeling program for GaAs MESFET digital and microwave integrated-circuit technology is described. GATES (for GaAs transistor engineering models) is designed to meet the needs of process, test, and manufacturing engineers who require answers to questions about how process parameters and tolerances affect device performance and uniformity, but who have limited access to large-computer modeling tools. The program makes extensive use of analytical models. The physical models used for ion implantation, dopant diffusion, and other process factors and the methods used to calculate carrier profiles, threshold voltages, layer resistivities, MESFET parasitic resistances, and I-V characteristics are discussed. The I-V curves can be fit to expressions suitable for use in circuit optimization codes such as SPICE. It is shown how to calibrate some of the physical quantities.

Anholt, Robert; Sigmon, Thomas W.

1989-04-01

486

Growth and properties of crystalline barium oxide on the GaAs(100) substrate  

SciTech Connect

Growing a crystalline oxide film on III-V semiconductor renders possible approaches to improve operation of electronics and optoelectronics heterostructures such as oxide/semiconductor junctions for transistors and window layers for solar cells. We demonstrate the growth of crystalline barium oxide (BaO) on GaAs(100) at low temperatures, even down to room temperature. Photoluminescence (PL) measurements reveal that the amount of interface defects is reduced for BaO/GaAs, compared to Al{sub 2}O{sub 3}/GaAs, suggesting that BaO is a useful buffer layer to passivate the surface of the III-V device material. PL and photoemission data show that the produced junction tolerates the post heating around 600?°C.

Yasir, M.; Dahl, J.; Lång, J.; Tuominen, M.; Punkkinen, M. P. J.; Laukkanen, P., E-mail: pekka.laukkanen@utu.fi; Kokko, K. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland)] [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Kuzmin, M. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland) [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Ioffe Physical-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021 (Russian Federation); Korpijärvi, V.-M.; Polojärvi, V.; Guina, M. [Optoelectronics Research Centre, Tampere University of Technology, FI-33101 Tampere (Finland)] [Optoelectronics Research Centre, Tampere University of Technology, FI-33101 Tampere (Finland)

2013-11-04

487

0.25-micron gate millimeter-wave ion-implanted GaAs MESFET's  

NASA Astrophysics Data System (ADS)

Quarter-micrometer gated ion-implanted GaAs MESFETs which demonstrate device performance comparable to AlGaAs/InGaAs pseudomorphic HEMTs (high-electron mobility transistors) have been successfully fabricated on 3-in-diameter GaAs substrates. The MESFETs show a peak extrinsic transconductance of 480 mS/mm with a high channel current of 720 mA/nm. From S-parameter measurements, the MESFETs show a peak current-gain cutoff frequency ft of 68 GHz with an average ft of 62 GHz across the wafer. The 0.25-micron gate MESFETs also exhibit a maximum-available-gain cutoff frequency ft greater than 100 GHz. These results are the first demonstration of potential volume production of high-performance ion-implanted MESFETs for millimeter-wave application.

Wang, G. W.; Feng, Milton; Lau, C. L.; Ito, C.; Lepkowski, Thomas R.

1989-05-01

488

High-performance millimeter-wave ion-implanted GaAs MESFET's  

NASA Astrophysics Data System (ADS)

GaAs MESFETs with ion-implanted active channels have been fabricated on 3-inch-diameter GaAs substrates; the MESFETs demonstrate device performance comparable with that of AlGaAs/InGaAs pseudomorphic HEMT (high-electron-mobility transistor) devices. Implanted MESFETs with 500-nm gate lengths exhibit an extrinsic transconductance of 350 mS/mm. From S-parameter measurements, a current-gain cutoff frequency f(t) of 48 GHz and a maximum-available-gain cutoff frequency f(max) greater than 100 GHz are achieved. These results clearly demonstrate the suitability of ion-implanted MESFET technology for mm-wave discrete-device, high-density digital, and monolithic microwave and mm-wave IC applications.

Wang, G. W.; Feng, Milton; Lau, C. L.; Ito, C.; Lepkowski, Thomas R.

1989-02-01

489

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

490

[Revisiting bipolar disorder].  

PubMed

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

Senjyu, Yoshika; Ozawa, Hiroki

2007-09-01

491

Gyrator employing field effect transistors  

NASA Technical Reports Server (NTRS)

A gyrator circuit of the conventional configuration of two amplifiers in a circular loop, one producing zero phase shift and the other producing 180 deg phase reversal is examined. All active elements are MOS field effect transistors. Each amplifier comprises a differential amplifier configuration with current limiting transistor, followed by an output transistor in cascode configuration, and two load transistors of opposite conductivity type from the other transistors. A voltage divider control circuit comprises a series string of transistors with a central voltage input to provide control, with locations on the amplifiers receiving reference voltages by connection to appropriate points on the divider. The circuit produces excellent response and is well suited for fabrication by integrated circuits.

Hochmair, E. S. (inventor)

1973-01-01

492

[Bipolar depression and suicidal behavior].  

PubMed

Suicide is a frequent and tragic consequence of bipolar depression. The prevention of suicidal behavior (SB) need an assessment of vulnerability traits related related to SB (personal suicide history, impulsive traits...), characteristics of depression (mixed depression, subtype of bipolar disorder...), psychiatric comorbidities and stressors psycho-social. Meanwhile, the characteristics of suicidal behavior (ie: severe or multiple attempts) suggest a diagnosis of bipolar disorder rather than major depressive disorder. In addition to a correct screening of bipolar disorders and assessment of suicidal behavior, the removal of lethal means, networking and treatment of depression reduces the risk of suicidal behavior. Finally, lithium may have a particular interest in subjects at high risk of suicide. PMID:22212869

Guillaume, S; Courtet, P; Samalin, L

2011-12-01

493

Nonmagnetic semiconductor spin transistor  

NASA Astrophysics Data System (ADS)

We propose a spin transistor using only nonmagnetic materials that exploits the characteristics of bulk inversion asymmetry (BIA) in (110) symmetric quantum wells. We show that extremely large spin splittings due to BIA are possible in (110) InAs/GaSb/AlSb heterostructures, which together with the enhanced spin decay times in (110) quantum wells demonstrates the potential for exploitation of BIA effects in semiconductor spintronics devices. Spin injection and detection is achieved using spin-dependent resonant interband tunneling and spin transistor action is realized through control of the electron spin lifetime in an InAs lateral transport channel using an applied electric field (Rashba effect). This device may also be used as a spin valve, or a magnetic field sensor.

Hall, K. C.; Lau, Wayne H.; Gündo?du, K.; Flatté, Michael E.; Boggess, Thomas F.

2003-10-01

494

High voltage power transistor development  

NASA Technical Reports Server (NTRS)

Design considerations, fabrication procedures, and methods of evaluation for high-voltage power-transistor development are discussed. Technique improvements such as