Strain effects associated with SiO layers evaporated onto GaAs

Abstract

Piezobirefringence is employed in a study of the strain fields associated with SiO stripes evaporated onto GaAs and GaP substrates. The stress fields in the substrates due to semi-infinite SiO stripes are calculated and compared with the stress distributions deduced from elastobirefringence studies. The stress distribution in the SiO along the interface is calculated and a technique is proposed to determine the magnitude of the stress in the SiO layer from birefringence measurements on the substrate. The local stresses beneath the SiO layer deduced from the measurements approach the yield stress of the Pb-based alloys used in Josephson Computer technology.