The temperature dependent current gain of heterojunction bipolar transistors

DC I-V characteristics of AlGaN/GaN heterojunction bipolar transistors (HBTs) and GaN homojunction bipolar transistors (BJTs) are analyzed in the temperature range of 200-450 K. At low current levels, the adverse effects of poor ohmic contacts coupled with paths of high leakage make it difficult to extract intrinsic device operation ["Explanation of anomalous current gain observed in GaN based bipolar transistors", Xing et al. IEEE Elect. Dev. Lett. 24(1) 2003:p.4-6]. At intermediate current levels, owing to enhanced ionization of Mg in the base, the HBTs show an increase in current gain resulting from mitigated current crowding, and the BJTs show a decrease in current gain resulting from reduction of emitter injection coefficient. The offset voltage dependence on temperature is also explained.

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Effects of Temperature and Stress on the InGaP/GaAs Heterojunction Phototransistor

Journal of Science and Technology Issue on Information and Communications Technology ◽

10.31130/ict-ud.2021.112 ◽

2021 ◽

Vol 19 (6.2) ◽

pp. 28

Author(s):

Phuc Hong Than ◽

Tran Thi Tra Vinh ◽

Le Thi My Hanh ◽

Than Quang Tho ◽

Nguyen Vu Anh Quang ◽

...

Keyword(s):

Heterojunction Bipolar Transistors ◽

Stress Test ◽

Optical Gain ◽

Bipolar Transistors ◽

Current Gain ◽

Temperature Dependent ◽

Collector Current ◽

Electrical Stress ◽

Before And After ◽

Higher Temperature

Although the effects of electrical stress and temperature on the performance of the InGaP/GaAs heterojunction bipolar transistors (HBTs) have been widely studied and reported, little or none was reported for the InGaP/GaAs heterojunction phototransistors (HPTs) in the literature. In this paper, we discuss the temperature-dependent characteristic of InGaP/GaAs HPTs before and after electrical stress and assess the effectiveness of the emitter-ledge passivation, which was found to effectively keep the InGaP/GaAs HBTs from degrading at higher temperature or after an electrical stress. The emitter-ledge passivation is also effective keeping a higher optical gain even at higher temperature. An electrical stress was given to the HPTs by keeping the collector current at 60 mA for 15 min. Since the collector current density as an electrical stress is 24 A/cm2 and much smaller than the stress usually given to smaller HBTs for the stress test, the decreased optical gain was not observed when it was given at room temperature. However, when it was given at 420 K, significant decreases of the current gain and optical gain were observed at any temperature. Nevertheless, the emitter-ledge passivation was found effective in minimizing the decreases of the current gain and optical gain.

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The collapse of current gain in multi-finger heterojunction bipolar transistors: its substrate temperature dependence, instability criteria, and modeling

IEEE Transactions on Electron Devices ◽

10.1109/16.324577 ◽

1994 ◽

Vol 41 (10) ◽

pp. 1698-1707 ◽

Cited By ~ 74

Author(s):

W. Liu ◽

A. Khatibzadeh

Keyword(s):

Substrate Temperature ◽

Temperature Dependence ◽

Heterojunction Bipolar Transistors ◽

Bipolar Transistors ◽

Current Gain ◽

Instability Criteria

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Current gain-Early voltage products in heterojunction bipolar transistors with nonuniform base bandgaps

IEEE Electron Device Letters ◽

10.1109/55.116947 ◽

1991 ◽

Vol 12 (12) ◽

pp. 661-663 ◽

Cited By ~ 41

Author(s):

E.J. Prinz ◽

J.C. Sturm

Keyword(s):

Heterojunction Bipolar Transistors ◽

Bipolar Transistors ◽

Current Gain

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Current gain increase in AlGaAs/GaAs heterojunction bipolar transistors using AlGaAs layer overgrowth

Applied Physics Letters ◽

10.1063/1.112065 ◽

1994 ◽

Vol 65 (11) ◽

pp. 1403-1405 ◽

Cited By ~ 3

Author(s):

S. R. D. Kalingamudali ◽

A. C. Wismayer ◽

R. C. Woods ◽

J. S. Roberts

Keyword(s):

Heterojunction Bipolar Transistors ◽

Bipolar Transistors ◽

Current Gain ◽

Algaas Layer

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Prevention of InP/InGaAs/InP Double Heterojunction Bipolar Transistors from Current Gain Reduction during Passivation

MRS Proceedings ◽

10.1557/proc-833-g3.7 ◽

2004 ◽

Vol 833 ◽

Author(s):

Byoung-Gue Min ◽

Jong-Min Lee ◽

Seong-Il Kim ◽

Chul-Won Ju ◽

Kyung-Ho Lee

Keyword(s):

Heterojunction Bipolar Transistors ◽

Silicon Oxide ◽

Surface Recombination ◽

Surface States ◽

Bipolar Transistors ◽

Base Layer ◽

Current Gain ◽

Device Structure ◽

Double Heterojunction ◽

Gain Reduction

ABSTRACTA significant degradation of current gain of InP/InGaAs/InP double heterojunction bipolar transistors was observed after passivation. The amount of degradation depended on the degree of surface exposure of the p-type InGaAs base layer according to the epi-structure and device structure. The deposition conditions such as deposition temperature, kinds of materials (silicon oxide, silicon nitride and aluminum oxide) and film thickness were not major variables to affect the device performance. The gain reduction was prevented by the BOE treatment before the passivation. A possible explanation of this behavior is that unstable non-stoichiometric surface states produced by excess In, Ga, or As after mesa etching are eliminated by BOE treatment and reduce the surface recombination sites.

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