Modeling of transport and film growth over patterned substrates

摘要

ysis of transport and film growth over masked and nonplanar substrates is presented. Special emphasis is placed upon modelling strategies with regard to whether the gas is in the viscous or rarefied flow regimes and the appropriate assumptions which can be made to simplify the model. A coupled volume and surface diffusion model is used to describe selective and nonplanar growth in the viscous flow regime. Results of a parametric study suggest that diffusion in the gas phase is responsible for the growth rate enhancements and nonuniformity which accompany patterned substrate growth. The direct simulation Monte Carlo method is used to model rarefied gas flows and deposition over patterned substrates where the mean free path of the gas molecules is of the same order or larger than the characteristic feature size.