Effective compliant substrate for low-dislocation relaxed SiGe growth

An effective compliant substrate was fabricated for the growth of high-qual ity relaxed SiGe templates, by synthesizing a 20% B2O3 concentration borosi licate glass (BSG) in the silicon on insulator wafers. Substrates with 5%, 10%, and 20% B2O3 were used for 150 nm Si0.75Ge0.25 epitaxy. Double-axis x- ray diffraction measurements determined the relaxation and composition of t he Si1-xGex layers. Cross-sectional transmission electron microscopy was us ed to observe the lattice of the SiGe epilayer and the Si substrate, disloc ation density, and distribution. Raman spectroscopy was combined with step etch to study the samples. The strain sharing effect of the 20% BSG substra te was demonstrated. Thus, we concluded that this compliant substrate is a highly promising candidate for the growth of low-dislocation relaxed SiGe l ayers. (C) 2001 American Institute of Physics.