scholarly journals Measurement of the bandgap narrowing in the base of Si homojunction and Si/Si1-xGex heterojunction bipolar transistors from the temperature dependence of the collector current

1994 ◽  
Vol 04 (C6) ◽  
pp. C6-123-C6-126
Author(s):  
P. Ashburn ◽  
A. Nouailhat ◽  
A. Chantre
Keyword(s):  
Temperature Dependence ◽  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Collector Current ◽  
Bandgap Narrowing

Current Gain of 4H-SiC Bipolar Transistors Including the Effect of Interface States

2005 ◽  
Vol 483-485 ◽  
pp. 889-892 ◽  
Author(s):  
Martin Domeij ◽  
Erik Danielsson ◽  
Hyung Seok Lee ◽  
Carl Mikael Zetterling ◽  
Mikael Östling
Keyword(s):  
Side Wall ◽  
Interface States ◽  
Bipolar Transistors ◽  
Current Gain ◽  
Poor Agreement ◽  
Collector Current ◽  
Bandgap Narrowing ◽  
Pulsed Measurements ◽  
Emitter Junction ◽  
Constant Distribution

The current gain (b) of 4H-SiC BJTs as function of collector current (IC) has been investigated by DC and pulsed measurements and by device simulations. A measured monotonic increase of b with IC agrees well with simulations using a constant distribution of interface states at the 4H-SiC/SiO2 interface along the etched side-wall of the base-emitter junction. Simulations using only bulk recombination, on the other hand, are in poor agreement with the measurements. The interface states degrade the simulated current gain by combined effects of localized recombination and trapped charge that influence the surface potential. Additionally, bandgap narrowing has a significant impact by reducing the peak current gain by about 50 % in simulations.

scholarly journals Study on Possible Double Peaks in Cutoff Frequency Characteristics of AlGaAs/GaAs HBTs by Energy Transport Simulation

VLSI Design ◽  
1998 ◽  
Vol 8 (1-4) ◽  
pp. 437-442
Author(s):  
T. Okada ◽  
K. Horio
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Energy Transport ◽  
Transport Model ◽  
Cutoff Frequency ◽  
Bipolar Transistors ◽  
Electron Velocity ◽  
Collector Current ◽  
Double Peak ◽  
Double Peaks ◽  
Energy Profiles

By using an energy transport model, we simulate cutoff frequency fT  versus collector current density IC characteristics of npn−n AlGaAs/GaAs heterojunction bipolar transistors (HBTs) with various n−-collector thickness and n−-doping densities. It is found that the calculated fT  characteristics show double peak behavior when the n−- layer is thick enough and the n−-doping is high enough to allow existence of neutral n−- region. The mechanism of the double peak behavior is discussed by studying energy band diagrams, electron-energy profiles and electron-velocity profiles. Particularly, we discuss the origin of the second peak (at higher IC) which is not usually reported experimentally.

Study of The Transversal Electron Mobility in Heterojunction Bipolar Transistors with Strained SI1−x Gex-Base

1992 ◽  
Vol 281 ◽  
Author(s):  
J. Poortmans ◽  
M. Caymax ◽  
A. Van Ammel ◽  
M. Libezny ◽  
J. Nijs
Keyword(s):  
Heterojunction Bipolar Transistors ◽  
Electron Mobility ◽  
Doping Level ◽  
Theoretical Calculations ◽  
Bipolar Transistors ◽  
Effective Density ◽  
Collector Current ◽  
Strained Si ◽  
Strained Layers ◽  
B Doping

ABSTRACTThe effective transversal mobility of the minority carrier electrons in asymmetrically strained p-type Si1−x Gex -layers, grown on a Si (100) substrate, is studied as a function of boron doping concentration and Ge-content x. The experiments are based on the temperature dependence (290 to 400K) of the collector current enhancement of heterojunction bipolar transistors with a pseudomorphic Si1−x Gex-base. The interpretation of these results is based on new insights about the effective density of states in the valence band of these strained layers [1]. We will present first experimental evidence of the theoretical calculations in [1]. From this we will derive then the value of the NcNv -product for the strained Si1−x Gex-alloy. This allows to extract the ratio of the electron mobility in Si and strained Si1−xGex. We found an enhancement of the mobility when the B-doping level is around 1018 cm−3 and 0.08<x<0.16. At higher values of the Ge-content and the doping level, the enhancement is reduced again.

Simulation of Collector Current Distribution in Heterojunction Bipolar Transistors Using Newly Proposed Empirical Expression

1996 ◽  
Vol 35 (Part 1, No. 2A) ◽  
pp. 574-577
Author(s):  
Teruyuki Shimura ◽  
Masayuki Sakai ◽  
Manabu Kato ◽  
Sigekazu Izumi ◽  
Ryo Hattori ◽  
...  
Keyword(s):  
Current Distribution ◽  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Collector Current ◽  
Empirical Expression

High-Power Characteristics of GaN/InGaN Double Heterojunction Bipolar Transistors with a Regrown p-InGaN Base Layer

2003 ◽  
Vol 798 ◽  
Author(s):  
Toshiki Makimoto ◽  
Yoshiharu Yamauchi ◽  
Kazuhide Kumakura
Keyword(s):  
High Power ◽  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Base Layer ◽  
Collector Current ◽  
Power Characteristics ◽  
Low Leakage ◽  
Low Leakage Current ◽  
Double Heterojunction ◽  
Extrinsic Base

ABSTRACTWe have investigated high-power characteristics of GaN/InGaN double heterojunction bipolar transistors on SiC substrates grown by metalorganic vapor phase epitaxy. The p-InGaN extrinsic base layers were regrown to improve ohmic characteristics of the base. Base-collector diodes showed low leakage current at their reverse bias voltages due to a wide bandgap of a GaN collector, resulting in a high-voltage transistor operation. A 90 μm × 50 μm device operated up to a collector-emitter voltage of 28 V and a collector current of 0.37 A in its common-emitter current-voltage characteristics at room temperature, which corresponds to a DC power of 10.4 W. A collector current density and a power density are as high as 8.2 kA/cm2 and 230 kW/cm2, respectively. These results show that nitride HBTs are promising for high-power electronic devices.

Temperature dependence of current gain in AlGaAs/GaAs heterojunction bipolar transistors

1984 ◽  
Vol 45 (10) ◽  
pp. 1086-1088 ◽  
Author(s):  
Naresh Chand ◽  
Russ Fischer ◽  
Tim Henderson ◽  
John Klem ◽  
William Kopp ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Heterojunction Bipolar Transistors ◽  
Bipolar Transistors ◽  
Current Gain
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