Performance Prediction of InP/GaAsSb Double Heterojunction Bipolar Transistors for THz applications

TL;DR

This paper predicts the high-frequency performance of InP/GaAsSb double heterojunction bipolar transistors for THz applications using advanced multi-scale simulations, highlighting their potential and limitations.

Contribution

It introduces a multi-scale TCAD modeling approach to predict THz performance of InP/GaAsSb DHBTs, including device scaling effects and breakdown characteristics.

Findings

Peak transit frequency of 1.6 THz predicted for scaled DHBTs

Breakdown voltage estimated at 2.2 V

Self-heating and breakdown are key performance factors

Abstract

The intrinsic performance of "type-II" InP/GaAsSb double heterojunction bipolar transistors (DHBTs) towards and beyond THz is predicted and analyzed based on a multi-scale technology computer aided design (TCAD) modeling platform calibrated against experimental measurements. Two-dimensional hydrodynamic simulations are combined with 1-D full-band, atomistic quantum transport calculations to shed light on future DHBT generations whose dimensions are decreased step-by-step, starting from the current device configuration. Simulations predict that a peak transit frequency $f_{T,peak}$ of around 1.6 THz could be reached in aggressively scaled type-II DHBTs with a total thickness of 256 nm and an emitter width $W_E$ of 37.5 nm. The corresponding breakdown voltage $BV_{CEO}$ is estimated to be 2.2 V. The investigations are put in perspective with two DHBT performance limiting factors, self-heating and breakdown characteristics.