Raman study of strain distribution in interface region of GaAs/GaP heteroepitaxial layers grown by MBE

Abstract The strain introduced in heteroepitaxial layers due to a large lattice mismatch depends on the layer thickness. Studies on the accommodation of this strain is made by Raman spectroscopy in gallium arsenide with various layer thicknesses grown on the gallium phosphide substrate by MBE. The dominant growth mode is found to be three-dimensional when the layer thickness is less than about 15 nm, whereas two-dimensional growth is dominant in thicker layers. We deduce the strain distribution in the epitaxial layer from assumption (i.e., the observed line shape is composed of signals from each part of different depth in the epitaxial layer).