Application of InGaAs/GaAs superlattice-base structure for InGaP/GaAs superlattice-emitter bipolar transistor

The performance of an InGaP/GaAs superlattice-emitter bipolar transistor with InGaAs/GaAs superlattice-base structure is demonstrated by experimental results. The injecting electrons from superlattice emitter are easy to transport into the superlattice-base region for promoting the collector current by tunneling behavior. Furthermore, the average energy gap of base regime is substantially reduced by the use of InGaAs/GaAs superlattice structure for the requirement of low turn-on voltage. Experimentally, the transistor exhibits a maximum common-emitter current gain of 295 and a relatively low collector-emitter offset voltage of only 16 mV. In particular, the ideality factor of collector current near to unity is obtained.