Title

A Physics-Based, Analytical Heterojunction Bipolar-Transistor Model Including Thermal And High-Current Effects

Title - Alternative

IEEE Trans. Electron Devices

Keywords

P-N; Algaas/Gaas; Resistance; Time; Hbts; Engineering, Electrical & Electronic; Physics, Applied

Abstract

We present a detailed, analytical model to predict the dc and high-frequency performance of AlGaAs/GaAs graded heterojunction bipolar transistors (HBT's). The model is developed based on the relevant device physics such as current-induced base pushout and thermal effect. The current gain, cutoff frequency, and maximum frequency versus the collector current density, which is a function of the applied voltage as well as the corresponding temperature in the HBT, are calculated. Our results suggest that the conventional HBT model, which assumes the HBT temperature is the same as that of the ambient, can overestimate the three figures of merit considerably when the collector current density is high. Furthermore, it is shown that the present model correctly explains the experimentally observed HBT high-current behavior like the rapid fall-off of the current gain and cutoff frequency. The model predictions compare favorably with the results obtained from a model which solves numerically the Poisson and continuity equations coupled with the lattice heat equation.

Publication Title

Ieee Transactions on Electron Devices

Volume

40

Issue/Number

9

Publication Date

1-1-1993

Document Type

Article

Language

English

First Page

1570

Last Page

1577

WOS Identifier

WOS:A1993LU39400001

ISSN

0018-9383

Share

COinS