Statistical Extraction of Normally and Lognormally Distributed Model Parameters for Power MOSFETs

摘要

In this paper, we propose a new statistical model parameter extraction method for compact power device models. While existing parameter extraction methods are only applicable for the parameters that follow normal distributions, the proposed method can simultaneously incorporate the model parameters that follow lognormal distributions. In addition, a set of dominant model parameters, which largely contributes to the characteristic variation of power MOSFETs, has been studied on the basis of the proposed statistical parameter modeling. Through the numerical analysis upon measured drain currents of planar and trench SiC power MOSFETs, we demonstrate that the fluctuation of the current characteristics can be represented by a small number of dominant parameters. In our example, threshold voltage and current scaling factor are identified to be particularly important to approximate the fluctuation of the current characteristics in both structures.