Behavior and Chemical Reactions of Liquid Si and Ge on SiС Surface

Abstract

The interaction of liquid Ge and Si droplets, deposited by CVD, on the surface of 4H-SiC single-crystals is studied. It was found that at 1500 °C Ge forms micrometric droplets while Si forms nanometric dots. While the Si dots do not seem to interact significantly with SiC, the Ge droplets have the tendency to dissolve the Si from the seed. This mechanism not only happens during deposition but also during the cooling. If the cooling rate is too slow, Ge evaporates from the droplets while dissolving Si so that, at the end, the droplets look like to have been fully converted from Ge to Si.