Stress distribution mapping of GaAs on Si conformal layers

Cathodoluminescence and micro-Raman studies of GaAs on Si layers grown by the conformal method show a characteristic quasiperiodic modulation of the stress distribution perpendicular to the growth direction. Using the capability of the spectral imaging in the cathodoluminescence technique, the stress distribution has been directly mapped. The Raman data give accurate information of the stress level variations in the upper part of the samples, which compare well with the luminescence data. The origin of the quasiperiodic stress variations are discussed in terms of the growth geometry, taking account of the presence of a compliant thin SiO2 layer in between the Si substrate and the 110 > growing GaAs layer. (c) 2007 American Institute of Physics.