Negative Transconductance in AlGaAs/GaAs Heterojunction Bipolar Transistors

1 November 1990

journal article
Published by IOP Publishing in Japanese Journal of Applied Physics

Vol. 29 (11R)
https://doi.org/10.1143/jjap.29.2376

Abstract

Negative transconductance has been observed and analyzed for the first time in AlGaAs/GaAs HBTs when V _BE is larger than 1.7 volts. A newly developed equivalent circuit model with an additional external base-emitter diode and a temperature-dependent resistor which corresponds to the intrinsic base resistance is proposed on the basis of experimental data for a pulse-biased I-V characteristic and temperature dependence of the sheet resistance for p-GaAs layers. Using this model, it is shown that negative transconductance is one of the novel characteristics in HBTs and is attributed to the drop in the input voltage across the intrinsic base resistance which increases with the input power through heat generation.

Keywords

This publication has 9 references indexed in Scilit:

Thermal design studies of high-power heterojunction bipolar transistors
IEEE Transactions on Electron Devices, 1989
Transit-time reduction in AlGaAs/GaAs HBTs utilizing velocity overshoot in the p-type collector region
IEEE Electron Device Letters, 1988
A possible near-ballistic collection in an AlGaAs/GaAs HBT with a modified collector structure
IEEE Transactions on Electron Devices, 1988
Transport and related properties of (Ga, Al)As/GaAs double heterostructure bipolar junction transistors
IEEE Transactions on Electron Devices, 1987
A proposed structure for collector transit-time reduction in AlGaAs/GaAs bipolar transistors
IEEE Electron Device Letters, 1986
Collector-top GaAs/AlGaAs heterojunction bipolar transistors for high-speed digital ICs
Electronics Letters, 1986
Temperature dependence of current gain in AlGaAs/GaAs heterojunction bipolar transistors
Applied Physics Letters, 1984
GaAs/(Ga,Al)As heterojunction bipolar transistors with buried oxygen-implanted isolation layers
IEEE Electron Device Letters, 1984
High-frequency characteristics of AlGaAs/GaAs heterojunction bipolar transistors
IEEE Electron Device Letters, 1984