Linking simulated polycrystalline thin film microstructures to physical vapor deposition conditions
Joseph M. Monti, James A. Stewart, Joyce Custer, David P. Adams, Diederik Depla, Rémi Dingreville
Abstract
We present a generalized multi-phase-field model to predict the growth of polycrystalline thin films fabricated by physical vapor deposition. The model accounts for the explicit transport of atomic species to the substrate and the competing diffusion processes on the surface and in the bulk of the film leading to the formation of films with specific microstructures. We used magnetron sputtering conditions (pressure, voltage, working distance, substrate orientation) to calculate the energy and direction of the arriving atoms at the substrate using Monte Carlo simulations with the SiMTRA code. Our simulation results capture the dependence of the microstructure on deposition conditions, and delineate the relationship between process parameters and the formation of columnar microstructures and surface roughness characteristic of thin films. These simulation predictions are in agreement with transmission electron microscopy characterization of sputtered films. Through our systematic investigation of competing growth mechanisms, we provide insights into the complex relationships between deposition conditions and bulk and surface morphologies.