Kinetic Model for Layer-By-Layer Homoepitaxial Growth

Abstract

AbstractThe new kinetic model for homoepitaxial growth on a singular surface is presented. The model combines a familiar rate equations approach and a concept of a feeding zone that allows to connect the growth processes in neighbouring monolayers. The model involves the irreversible 2D nucleation, growth and coalescence of the islands in each growing monolayer and consists of an infinite set of coupled rate equations for the adatom and island densities and coverage in successive monolayers. With using this model the temporal evolution of the surface morphology (rms roughness and RHEED intensity) is studied. It is shown that the growth mode is fully determined by a single dimensionless parameter μ = D/J where D and J are the normalized surface diffusion coefficient and deposition flux, respectively. There exist five regions of m corresponding different growth regimes varying from smooth 2D layer-by-layer growth at sufficiently high values of μ (>108) to very rough Poisson-like random deposition growth at μ<10−4. The extension of the model to the case of heteroepitaxy is also discussed.