A Multiscale TCAD Approach for the Simulation of InP DHBTs and the Extraction of Their Transit Times

A multiscale technology computer-aided design (TCAD) simulation methodology is presented to calculate the intrinsic transit time of InP double heterojunction bipolar transistors (DHBTs). A 2-D hydrodynamic (HD) simulator is employed to produce the dc characteristics and electrostatic potentials of the selected devices. Utilizing the 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 the experimental measurements. The observed underestimations of the experimental transit times are justified with the physics-based compact model HiCuM, thus providing a basis for structure and performance optimizations toward real terahertz transistors.