Simulation of electrical characteristics of InP double-heterojunction bipolar transistors with InGaAsSb base

We study the effect of antimony (Sb) content in the InGaAsSb base layer of InP double-heterojunction bipolar transistors (DHBTs), under the condition of lattice match, by using a two-dimensional device simulator Medici. Careful calibration of physical parameters is first done to ensure that the simulation result matches data measured from a reference device. When the composition of Sb in the InGaAsSb base region is varied, the conduction band offset (ΔEC), effective density of states in conduction band and valence band (NC, NV), bandgap energy (EG), and intrinsic carrier concentration (ni) are changed accordingly. These semiconductor material parameters are considered in the simulation to compare the electrical characteristics of the DHBT. In addition to the Sb composition, different materials of In0.52Al0.48As or InP in the emitter are simulated. The study on Sb content in the base and the heterostructure of E-B junction helps the development and optimization of InGaAsSb DHBTs.