A multi-scale TCAD approach for the simulation of InP DHBTs and the extraction of their transit times

A multi-scale technology computer aided design (TCAD) simulation methodology is presented to calculate the intrinsic transit time of InP double heterojunction bipolar transistors (DHBTs). A two-dimensional (2-D) hydrodynamic (HD) simulator is employed to produce the DC characteristics and electrostatic potentials of selected devices. Utilizing cuts of the obtained potential profiles as inputs, a 1-D full-band, atomistic quantum transport (QT) solver is then deployed to determine the ballistic electronic transport properties of these components. The transit times of DHBTs based on InGaAs/InP and GaAsSb/InP technologies are finally investigated with the proposed approach. Good qualitative agreements are observed with experimental measurements, thus providing a basis for structure and performance optimizations towards real terahertz (THz) transistors. Factors contributing to the discrepancies between simulations and experiments are also discussed.