Title :
Analytical model for the AlGaAs/GaAs multiemitter finger HBT including self-heating and thermal coupling effects
Author :
Liou, J.J. ; Liou, L.L. ; Huang, C.I.
Author_Institution :
Dept. of Electr. & Comput. Eng., Univ. of Central Florida, Orlando, FL, USA
fDate :
12/1/1994 12:00:00 AM
Abstract :
An analytical model which can be used to predict the thermal as well as electronic behaviour of the multiple emitter heterojunction bipolar transistor (HBT) is presented. The model is developed from a knowledge of device make-up (doping concentrations, layer thicknesses etc.), and relevant physics (such as the effects of graded heterojunction, self-heating, thermal coupling and ballast emitter resistance) is included in a unified manner. Thermal runaway phenomenon observed in the multifinger HBT at high current levels has been successfully described. Experimental evidence obtained from six-finger and four-finger HBTs are included in support of the model. The thermal runaway phenomenon is caused by the uneven increase of the base and collector currents at elevated temperatures due to the thermal effect
Keywords :
III-V semiconductors; aluminium compounds; doping profiles; gallium arsenide; heterojunction bipolar transistors; microwave bipolar transistors; microwave power transistors; power bipolar transistors; AlGaAs-GaAs; AlGaAs/GaAs; ballast emitter resistance; base currents; collector currents; doping concentrations; graded heterojunction; layer thicknesses; microwave bipolar transistors; multiemitter finger HBT; power transistors; self-heating effects; thermal coupling effects; thermal runaway phenomenon;
Journal_Title :
Circuits, Devices and Systems, IEE Proceedings -
DOI :
10.1049/ip-cds:19941394
