Temperature dependent common emitter current gain and collector-emitter offset voltage study in AlGaN/GaN heterojunction bipolar transistors

2001 ◽  
Vol 22 (4) ◽  
pp. 157-159 ◽  
Author(s):  
J.J. Huang ◽  
M. Hattendorf ◽  
M. Feng ◽  
D.J.H. Lambert ◽  
B.S. Shelton ◽  
...  
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Current Gain ◽  
Temperature Dependent ◽  
Emitter Current ◽  
Offset Voltage

TEMPERATURE DEPENDENT I-V CHARACTERISTICS OF AlGaN/GaN HBTS AND GaN BJTS

2004 ◽  
Vol 14 (03) ◽  
pp. 819-824 ◽  
Author(s):  
HUILI G. XING ◽  
UMESH K. MISHRA
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Ohmic Contacts ◽  
Voltage Dependence ◽  
Bipolar Transistors ◽  
Current Gain ◽  
Current Crowding ◽  
Temperature Dependent ◽  
Offset Voltage ◽  
Injection Coefficient ◽  
Device Operation

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.

Room and low temperature study of common emitter current gain in AlGaN/GaN heterojunction bipolar transistors

2001 ◽  
Vol 37 (6) ◽  
pp. 393 ◽  
Author(s):  
J.J. Huang ◽  
D. Caruth ◽  
M. Feng ◽  
D.J.H. Lambert ◽  
B.S. Shelton ◽  
...  
Keyword(s):  
Low Temperature ◽  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Current Gain ◽  
Emitter Current ◽  
Temperature Study

scholarly journals MOCVD-Grown InGa/GaAs Emitter Delta Doping Heterojunction Bipolar Transistors

2002 ◽  
Vol 25 (3) ◽  
pp. 239-243
Author(s):  
K. F. Yarn
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
High Gain ◽  
Bipolar Transistors ◽  
Heterojunction Bipolar Transistor ◽  
Current Gain ◽  
Offset Voltage ◽  
Delta Doping ◽  
Spacer Layer ◽  
Potential Spike ◽  
Low Offset

The influence of delta doping sheet at base-emitter (BE) junction for an InGaP/GaAs heterojunction bipolar transistor (HBT) with a 75Å undoped spacer layer is investigated. A common emitter current gain of 235, an offset voltage as small as 50mV and an Ic ideal factor of 1.01 are obtained, respectively. The use of delta doping sheet at BE junction results in a high gain and low offset voltage HBT. The improvement of current gain and offset voltage may be attributed to the reduction of BE potential spike by introducing a delta doping layer even without the BE junction passivation.

Reduction of Base Access Resistance in AlGaN/GaN Heterojunction Bipolar Transistors using GaInN Base Cap Layer and Selective Epitaxial Growth

2005 ◽  
Vol 892 ◽  
Author(s):  
Jay M Shah ◽  
Thomas Gessmann ◽  
Hong Luo ◽  
Yangang Xi ◽  
Kaixuan Chen ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Epitaxial Growth ◽  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Current Gain ◽  
Selective Epitaxial Growth ◽  
Offset Voltage ◽  
Specific Contact ◽  
Access Resistance ◽  
P Type

AbstractOne of the major challenges affecting the performance of Npn AlGaN/GaN heterojunction bipolar transistors (HBTs) is the high base access resistance, which is comprised of the base contact resistance and the base bulk resistance. A novel concept is proposed to reduce the base access resistance in Npn AlGaN/GaN HBTs by employing polarization-enhanced contacts and selective epitaxial growth of the base and emitter. In addition, this technique reduces the exposed base surface area, which results in a lower surface recombination current. Such a structure would enable better performance of AlGaN/GaN HBTs in terms of higher current gain and a lower offset voltage. Theoretical calculations on polarization-enhanced contacts predict p-type specific contact resistance lower than 10-5 Ωcm2. Experimental results using transmission line measurement (TLM) technique yield specific contact resistances of 5.6×10-4 Ωcm2 for polarization-enhanced p-type contacts and 7.8×10-2 Ωcm2 for conventional p-type contacts.

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

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.

SiC Heterojunction Bipolar Transistors with AlN/GaN Short-Period Superlattice Widegap Emitter

2010 ◽  
Vol 645-648 ◽  
pp. 1029-1032
Author(s):  
Hiroki Miyake ◽  
Tsunenobu Kimoto ◽  
Jun Suda
Keyword(s):  
Potential Barrier ◽  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Current Gain ◽  
Band Offset ◽  
Algan Layer ◽  
Emitter Current ◽  
Al Content ◽  
Short Period ◽  
Successful Control

In this study, new SiC-based heterojunction bipolar transistors (HBT) are proposed. An n-type AlN/GaN short-period superlattice (quasi-AlGaN) layer is grown on a SiC pn junction as a widegap emitter. By using quasi-AlGaN emitter, we have demonstrated successful control of band offset of AlGaN/SiC. Quasi-AlGaN/SiC HBT with an Al content over 0.5, which has no potential barrier to electron injection from an n-AlGaN emitter to a p-SiC base, exhibited a common-emitter current gain of β ~ 2.7, whereas the HBT with an Al content below 0.5 showed β ~ 0.1.

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