Implications of a model for instability during film growth for strained InGaAs and SiGe layers

Abstract
We analyzeexperiments on the morphology of strained InGaAs and SiGe layers using a nonequilibrium stability analysis. Stability diagrams for growingfilms as a function of the deposition rate, the temperature and the misfit are calculated and compared to experimental reports. We show that for InGaAs layers, the onset of surface roughening is due to an instability against simultaneous modulations of the surface profile and the composition. For SiGe, the onset of surface roughening cannot be described by an instability, but rather, is due to a nucleation mechanism.