Use of pseudomorphic GaInAs in Heterojunction Bipolar Transistors

Abstract This work investigates the use of pseudomorphic Ga 1−y In y As in the base of the Heterojunction Bipolar Transistor (HBT) as an alternative to GaAs. The strain induced by the lattice mismatch between GaAs and Ga 1−y In y As results in a decrease in common emitter current gain (β) when a uniform Ga 1−y In y As base is utilized. However, grading the In composition throughout the base in order to achieve a built-in quasi-electric field results in an increase in β.