Stress variations due to microcracks in GaAs grown on Si

Abstract

Luminescence studies of thick (≥5 μm) GaAs epitaxial layers grown on Si substrates reveal regions of nonuniform stress associated with the presence of microcracks. Using cathodoluminescence spectroscopy as a tool for microcharacterization, the magnitude of the stress, derived from the peak positions of the luminescence spectra, is shown to increase gradually as a function of distance from the intersection of two microcracks. The greatest degree of stress relief was found at this intersection.