[paper] Quasi-Fermi-Based Charge Transport Scheme for Device Simulation in Cryogenic

Quasi-Fermi-Based Charge Transport Scheme for Device Simulation 

in Cryogenic, Wide-Band-Gap, and High-Voltage Applications

Zlatan Stanojevic, Senior Member, IEEE, Jose Marıa Gonzalez-Medina, Member, IEEE, 

Franz Schanovsky, Member, IEEE, Markus Karner, Member, IEEE

TechRxiv. Preprint (2022) 

DOI:10.36227/techrxiv.21132637.v2 

Abstract: We present a novel approach to solving the transport problem in semiconductors. We reformulate the drift-diffusion equations in terms of the quasi-Fermi-energies as solution variables; a drastic increase in numerical stability is achieved, which permits the simulation of devices at cryogenic temperatures as well as wide-band-gap devices using double precision arithmetic, instead of extended precision arithmetic which would otherwise be required to solve these applications using regular drift-diffusion.

FIG: MOSFET transfer characteristics from 300K down to 4K simulated using FVM/SG/QFT at VDS=0.8V; despite only relying on double precision arithmetic, FVM/SG/QFT is capable of calculating contact currents down to 1e-310A.