GERMANIUM-RICH SIGE BULK SINGLE-CRYSTALS GROWN BY THE VERTICAL BRIDGMAN METHOD AND BY ZONE-MELTING

Silicon-germanium single crystals with a Si content up to 10 at. % hav e been grown by the vertical Bridgman technique in a monoellipsoid mir ror furnace. Single crystal regions up to 50 at. % have been realized by zone melting in a double ellipsoid mirror furnace. The typical high temperature gradients of radiation heated facilities (grad T up to 10 0 K/cm or even higher, depending on the sample geometry) reduce the oc currence of constitutional supercooling and stabilize the growth inter face. Photoluminescence measurements as well as rocking curves and etc h pit densities reveal a high crystal quality. Effective segregation c oefficients of Al, Ga, In, P, As, and Sb in Ge1-xSx (x<13 at. %) were determined. (C) 1998 American Vacuum Society.