HETEROEPITAXIAL LATERAL OVERGROWTH OF GEXSI1-X OVER SIO2/SI STRUCTURES BY LIQUID-PHASE EPITAXY

We investigate heteroepitaxial lateral overgrowth (HELO) of GexSi1-x and Ge over thermally oxidized Si. The GexSi1-x lamellae are grown by liquid phase epitaxy and are exclusively bound by {111} faces. The growth parameters which govern the shape, overgrowth width w and thickness h of the HELO GexSi1-x and Ge lamellae are presented. Heteroepitaxial lateral overgrowth is found to take place in all crystallographic directions on the (111) plane. The lateral overgrowth width w is quantitatively described as a function of seeding window orientation. Seeding windows parallel to <112> directions yield maximum overgrowth widths w up to 140-mu-m and lateral-to-vertical growth width aspect ratios w/h up to 11:1 under our chosen experimental conditions. The HELO GexSi1-x lamellae have a smoother surface morphology compared to GexSi1-x grown on unmasked Si.