An Analytical DC- and AC-Model for Vertical Smart Power DMOS Transistors

Smart Power MOS transistors serve primarily as an interface between digital control logic and the power load. Since they are also used in analog applications there are high demands on the accuracy of analytical models for circuit simulation. The approach for a physically based analytical model for vertical DMOS (double-diffused MOS) transistors which will be presented in this paper accounts for non-uniform channel doping-concentration in lateral direction, for space-charge limited current in the drift region and is able to describe the behavior of the device by means of a single formula. Our model is supported by two-dimensional numerical device simulations using BAMBI [l].