Simultaneous regulation of film thickness, surface roughness and porosity in a multiscale thin film growth process

This work focuses on simultaneous regulation of film thickness, surface roughness and porosity in a multiscale model of a thin film growth process using the inlet precursor concentration as the manipulated input. Specifically, a continuous macroscopic partial differential equation model is used to describe the dynamics of the gas phase. The thin film growth process is modeled via a microscopic kinetic Monte Carlo simulation model on a triangular lattice with vacancies and overhangs allowed to develop inside the film. Closed-form dynamic models of thin film surface profile and porosity are developed and used as the basis for the design of a model predictive control algorithm to simultaneously regulate film thickness, surface roughness and film porosity. Simulation results demonstrate the applicability and effectiveness of the proposed modeling and control approach by applying the proposed controller to the multiscale model.