Simulation method of impact ionization phenomenon of semiconductor device

摘要

A method of simulating an impact ionization phenomenon of a semiconductor device, by which an electric characteristic concerning the impact ionization phenomenon of the semiconductor device is obtained by setting a mesh in a space and by solving a Poisson equation, an electron current continuity equation and a hole current continuity equation which are discretized by what is called a control volume method. Further, regarding a current density defined on a mesh edge connecting adjacent mesh points, different values are used as an evaluation value of the current density at an upstream side, at which a carrier is cased to drift, and an evaluation value of the current density at a downstream side, respectively. Moreover, the difference between the current densities respectively obtained at the upstream side and the downstream side are set in such a manner as to be equal to a multiplication carrier current density caused by impact ionization of the carrier in the control volume corresponding to an edge of the mesh.