Regimes of Precursor-Mediated Epitaxial Growth

TL;DR

This paper analyzes epitaxial growth processes involving molecular precursors, identifying different kinetic regimes based on characteristic length scales, with a simple model illustrating the effects of various surface processes on growth behavior.

Contribution

It introduces a framework for classifying epitaxial growth regimes by analyzing characteristic length scales related to surface processes involving molecular precursors.

Findings

Identification of regimes based on length scale ratios

Model incorporating deposition, diffusion, desorption, and dissociation

Implications for experimental control of growth kinetics

Abstract

A discussion of epitaxial growth is presented for those situations (OMVPE, CBE, ALE, MOMBE, GSMBE, etc.) when the kinetics of surface processes associated with molecular precursors may be rate limiting. Emphasis is placed on the identification of various {\it characteristic length scales} associated with the surface processes. Study of the relative magnitudes of these lengths permits one to identify regimes of qualitatively different growth kinetics as a function of temperature and deposition flux. The approach is illustrated with a simple model which takes account of deposition, diffusion, desorption, dissociation, and step incorporation of a single precursor species, as well as the usual processes of atomic diffusion and step incorporation. Experimental implications are discussed in some detail.