Integrated description for random adsorption and 2D-island growth kinetics in thin film growth: Autocatalytic-reaction model and kinetic Monte Carlo simulation

Abstract

Because of the interplay among various surface processes, an integrated description of 2D film growth is usually a very difficult task. As far as adsorption–migration–desorption of precursors and the resultant nucleation, growth, and coalescence of 2D islands up to 1 monolayer are concerned, however, the autocatalytic-reaction (ACR) model [Phys. Rev. Lett. 82 (1999) 2334] can be a rare exception, which satisfactorily models the oxide film uptake curve during Si dry oxidation from a Langmuir to sigmoidal behaviors. A kinetic Monte Carlo (KMC) simulation, conducted to mimic the 2D growth of thin films, shows a similar shift from a Langmuir to sigmoidal uptake behavior by varying the parameters corresponding to adsorption, migration, and desorption. A comparison between ACR and KMC clarifies that the success of the ACR model lies in its effective inclusion of adsorption of species as well as of nucleation, growth, and coalescence of islands. A recipe is presented to translate the ACR parameters to KMC ones, which allows one to discuss the surface morphology based on the ACR analysis on the film uptake curve.