Cluster Model Study of the Incorporation Process of Excess Arsenic into Interstitial Positions of the GaAs Lattice

Abstract

AbstractWe study an As2 molecule approaching a planar, non-reconstructed, As terminated GaAs(001) surface by using a suitable cluster and quantum mechanical ab-initio calculation methods. During our calculations the As2 molecule is always oriented perpendicularly to the surface and its bonding length may vary. We find a metastable position below the growing surface which facilitates the incorporation of the leading As atom into an interstitial position of the crystal during growth. We give a first model for this incorporation process.