The effects of gamma irradiation on GaAs HBT

Abstract

The effects of gamma irradiation on Gallium-Arsenide (GaAs) Heterojunction Bipolar Transistor (HBT) is reported. DC and Radio Frequency (RF) performance are investigated for gamma doses up to 7 Mrad(Si). After 7Mrad(Si) gamma irradiation, an increase of base current (lb) is observed, the change is thought to be mainly due to the reduction of the effective minority carrier lifetime (τ) in the n-type emitter. Besides, the cutoff frequency (fT) decreases, which is caused by the decrease of the electron mobility (µn) in the base and the collector-base space charge region.