Hints, Tips and Solutions

Q: How is temperature dependent breakdown voltage modeled in ATLAS?

A: Modeling of the increase in breakdown voltage at elevated temperatures requires a model to describe the temperature dependence of the impact ionization coefficients. In ATLAS, there are two impact ionization models that include lattice temperature dependence. They are the Crowell-Sze model[1] called using the command IMPACT CROWELL and the Selberrherr Model[2] called using the command IMPACT SELB.

Users do not need to explicitly turn on any temperature dependent model. The impact ionization coefficients are always calculated based on the local lattice temperature. The temperature dependence is identical whether the lattice temperature is a uniform elevated temperature set using MODELS TEMP= or if the simulation includes lattice heating in Giga.