Simulation of substrate contact effects on heavy ion-induced current transient in SiGe HBT

Abstract This paper presents an investigation into the impact of substrate contact structure on the heavy ion-induced current transient in silicon‑germanium heterojunction bipolar transistor (SiGe HBT) based on Technology Computer Aided Design (TCAD) simulation. The results show that the size of the heavily doped ring wall used for substrate contact extraction has a significant impact on the collector current transient features. In addition, the impact of the ring size is position-dependent. For the strike positions inside or near the collector-substrate (C S) junction, the variation of transient features is attributed to the shape and volume of the funnel potential. While for the strike positions far from the C S junction, the variation is dominated by the diffusion process of the ion-induced electrons.