Numerical issues in power device simulation and modelling

The important physical and numerical aspects that make numerical simulation of power devices a difficult task are reviewed. The basic set of equations that describe the electric field distribution and the current transport in semiconductor devices in the classical form is presented. Material and process specific parameters that are included in these equations are discussed, with emphasis on the effects commonly found in power devices. Geometry and range of operation are the other factors that result in slow and unstable simulation processes. Methods to overcome these difficulties are presented. Results from simulations of switching cycles in GTOs (gate turn-off thyristors) and breakdown in DMOS devices are presented. Finally, an outlook on future developments in the area of power device simulation and analysis is given