APPLICABILITY OF ONE-DIMENSIONAL DIFFUSION-MODEL FOR STEP COVERAGE ANALYSIS - COMPARISON WITH A SIMPLE MONTE-CARLO METHOD

Applicability of a one-dimensional reaction-diffusion model (ORDM) as a tool for analyzing the gas-solid phase transition rate process during chemical vapor deposition is tested by comparing its results with those predicted by a simple Monte Carlo method. The results reveal that the ORDM is applicable when the conditions of Knudsen number (Kn) <0.03, aspect ratio (As)>1.0, and reactive sticking coefficient (eta)<0.1 are fulfilled. At large Kn and large eta,the ORDM gives quite an erroneous result. The ORDM is also applicable to predict the grown film shape when eta<0.1, Kn much greater than 1.0, and As>2.0. (C) 1995 American Institute of Physics.