Influence of emitter-ledge thickness on the surface- recombination mechanism of InGaP/GaAs heterojunction bipolar transistor

In this work, the characteristics of InGaP/GaAs heterojunction bipolar transistors (HBTs) with various emitter-ledge thicknesses are comprehensively studied and demonstrated. Based on the two-dimensional analysis, some important parameters such as the recombination rate and DC characteristics are studied. The simulated analyses are in good agreement with experimental results. It is known that better HBT performance, including lower recombination rate in the surface channel, and higher DC current gain are obtained in the studied devices with the emitter ledge thickness between 100 and 200 Å.