Comprehensive simulation of the effects of process conditions on plasma enhanced chemical vapor deposition of silicon nitride

A numerical model for the deposition of silicon nitride using silane and ammonia mixture in a radio frequency plasma reactor has been developed. Plasma enhanced chemical vapor deposition process is simulated by combined analysis for the glow discharge, fluid flow and chemical reactions. The main goal is to investigate the effect of variations of the process parameters on the deposition rate, and uniformity of the resulting layer. The approach used is based on the theoretical partial differential equation models, without any empirical approximation of the critical data being used. Owing to the fact that the relevant equations are highly nonlinear, the discretization method is of great importance. A finite boxes method is used to solve the partial differential equations (PDEs), and a Scharfetter–Gummel method is used to discretize the electron and ion flux terms.