Common-emitter current gain of Al/sub x/Ga/sub 1-x/As/GaAs/GaAs heterojunction bipolar transistors operating at small collector current

摘要

A recently developed current gain model, which accounts for high-current effects and can adequately characterize the current gain at high collector current, is improved by including both interfacial and bulk space-charge-region recombination currents, resulting in a comprehensive model that predicts the current gain more accurately at small collector currents. Comparison of the model and measured data for an Al/sub 0.25/Ga/sub 0.75//GaAs/GaAs heterojunction bipolar transistor is included in support of the model.