New Irregular Mesh Technique Used in Three-Dimensional Simulation of Relaxation Semiconductors

The aim of this work is to simulate correctly in 3D space the phenomena that govern relaxation semiconductors. To avoid the relevant constraints of inadequate mesh a new technique for refining irregular meshing has been creating. Each length of the sample will be considered as a partial sum of a geometric series, the calculation of the argument of this series, will allow to calculate the distance between the nodes. In this paper we proposed to use an algorithm combined between Gummel and Newton Raphson algorithms to solve the partial differential equations, the linearization of transport equations is obtained by applying the finite difference method, which allowed us to calculate the relaxation time, life time and recombination rate. The results revealed appearance of a limited region called recombination front instead of charge space region, an improvement in computational time with a big precision for a 3D simulation, by letting to the user the choice of the distance to be discreet and the number of points wished without saturate the memory. This type of meshing is simple to apply and can be used to be applied as a solution to correctly simulate phenomena in structures at different areas for all the dimensions.