A Physics-Based Trap-Assisted Tunneling Current Model for Cryogenic Temperature Compact Modeling of SiGe HBTs

Abstract

The work presents a new physics-based compact model of trap-assisted tunneling (TAT) current in forward biased base-emitter junction. Such TAT current is negligible at room temperature, but becomes significant at cryogenic temperatures. Inclusion of TAT current and its separation from the total base current is not only important for lower VBE base current, but also affects extraction of the ideal base current. The model is successfully applied to a first-generation SiGe HBT technology from 43 to 110 K.