Thermal runaway analysis of high power AlGaAs/GaAs heterojunction bipolar transistors

Abstract

Thermal runaway study of multiple emitter AlGaAs/GaAs power HBTs using an analytical electro-thermal model is described. Thermal runaway causes the fatal destruction of the device under the voltage modulation mode of operation, and thermally-induced current instability of the device under the current modulation mode of operation. The kinetic relation between the thermal runaway and junction temperature rise is studied. The HBT power handling capabilities in relation to the device thermal resistance and ballasting schemes are discussed.<>