Title :
Rigorous treatment of the electro-thermal behaviour of multi-finger microwave power heterojunction bipolar transistors
Author :
Schneider, Jürgen ; Erben, Uwe ; Schumacher, Hermann
Author_Institution :
Dept. of Electron. Devices & Circuits, Ulm Univ., Germany
Abstract :
A thermo-electrical model for single and multi-finger Heterojunction Bipolar Transistors (HBTs) was developed. The electrical part is based on a thermionic emission-diffusion theory. The thermal part solves the nonlinear thermal boundary problem using an orthogonal function approximation. The high frequency performance of the whole transistor is determined, calculating the admittance matrix of each individual emitter cell. The influence of the base bandgap, the emitter spacing and metal airbridges on the RF performance of multi-finger HBTs is determined numerically and analytically. The impact of the emitter contact as a thermal shunt is demonstrated
Keywords :
current distribution; electric admittance; function approximation; heterojunction bipolar transistors; microwave bipolar transistors; microwave power transistors; power bipolar transistors; semiconductor device models; AlGaAs-GaAs; RF performance; admittance matrix; base bandgap; electro-thermal behaviour; emitter cell; emitter contact; emitter spacing; high frequency performance; metal airbridges; multi-finger HBT; multi-finger microwave power heterojunction bipolar transistors; nonlinear thermal boundary problem; orthogonal function approximation; single-finger HBT; thermal shunt; thermionic emission-diffusion theory; thermo-electrical model; Charge carrier processes; Electromagnetic heating; Electron emission; Fingers; Gallium arsenide; Heterojunction bipolar transistors; Microwave devices; Temperature; Thermal conductivity; Thermionic emission;
Conference_Titel :
High Speed Semiconductor Devices and Circuits, 1995. Proceedings., IEEE/Cornell Conference on Advanced Concepts in
Conference_Location :
Ithaca, NY
Print_ISBN :
0-7803-3970-3
DOI :
10.1109/CORNEL.1995.482539
