An effective compliant substrate for Si1-xGex growth was presented. A Si-on-insulator substrate was implanted with B and O forming 20wt% borosilicate glass within the SiO2. The addition of the borosilicate glass to the buried oxide acted to reduce the viscosity at the growth temperature of Si1-xGex, promoting the in situ elastic deformation of the thin Si (20nm) layer on the insulator. The sharing of the misfit between the Si and the Si1-xGex layers was observed and quantified by double-axis X-ray diffraction. In addition, the material quality was assessed using cross-sectional transmission electron microscopy, photoluminescence and etch-pit density measurements. No misfit dislocations were observed in the partially relaxed 150nm Si0.75Ge0.25 sample as-grown on a 20% borosilicate glass substrate. The threading dislocation density was estimated at 2 x 104/cm2 for 500nm Si0.75Ge0.25 grown on the 20% borosilicate glass substrate. This method may be used to prepare compliant substrates for the growth of low-dislocation relaxed SiGe layers.

An Effective Compliant Substrate for Low-Dislocation Relaxed Si1-xGex Growth. Y.H.Luo, J.L.Liu, G.Jin, J.Wan, K.L.Wang: Applied Physics A, 2002, 74[5], 699-702