TCAD Simulation of InP DHBTs With an In53.2Ga46.8As Base and InGaAsP Collector Grading

This work focuses on causes and improvements of non-linear behavior of InP DHBTs from a physical simulation point of view. The simulated devices are based on triple mesa structures with type-I band alignment employing a carbon doped In
53.2
Ga
46.8
As base, 0.5 μm emitter width and InGaAsP material in the collector region to improve the electron transport. Simulated OIP3 values differed by about 5 dB between two devices. RF performance, in terms of transit frequency and maximum frequency of oscillation, differed by about 75 GHz and 87 GHz for the same device designs. The improved design also showed better electron transport across the collector region, underlining the high sensitivity of device performance effected by the collector design.