Modeling heterogeneity and memory effects on the kinetic roughening of silica films grown by chemical vapor deposition

Abstract

We present discrete and continuum models to describe previous experiments on growth of chemical vapor deposited silica films at 611 K and 723 K [F. Ojeda et al., Phys. Rev. Lett. 84, 3125 (2000)]. Silica films deposited at 723 K show larger surface roughness already from the early stages of growth, a fact that was not explained by a previously proposed phenomenological stochastic equation for the interface height. This larger surface roughness and the concomitant development of higher local slopes seem to be correlated with the Kardar-Parisi-Zhang asymptotic scaling observed for the high-temperature conditions. Here, we explain these features on the basis of surface heterogeneity and short-range memory effects, which are assessed for our experimental system through spectroscopic measurements. By incorporating these effects into a random deposition model and related Langevin equations with correlated noise, we are able to account for the full set of experimental observations.