Enhancing the current gain in InP/InGaAs double heterojunction bipolar transistors using emitter edge thinning

摘要

This paper reports InP/InGaAs double heterojunction bipolar transistors (DHBTs) made with composite-collector designs. The current gains of the DHBTs without and with emitter edge-thinning designs are 125 and 180, respectively. The composition of the collector and the base currents is analysed from the Gummel plots. Experimental data demonstrate that emitter edge thinning can further reduce the surface recombination current of the InP/InGaAs DHBTs and thus dramatically improve current gain, even though the surface recombination in InP/InGaAs DHBTs is much less than in GaAs-based DHBTs.