The characterisation of GaAs on silicon using polarised laser light

MBE-grown gallium arsenide epitaxial layers on silicon, with thicknesses between 0.1 and 8.1 μm, have been studied using a simple rotating polariser multiple-angle-of-incidence ellipsometer. From these data, information on the roughness of the surfaces of the layers and the anisotropy of the refractive index of the layers has been obtained. The results are compared with data obtained on the same samples using scanning electron microscopy and conventional spectroscopic ellipsometry.