Initial stages in the carbonization of (111)Si by solid-source molecular beam epitaxy

Abstract

Silicon carbide can be reproducibly grown on (111)Si below 600 °C by carbonization using an elemental solid carbon source in molecular beam epitaxy. The initial stages were observed by in situ reflection high-energy electron diffraction. Prior to silicon carbide growth, the continuous carbon flux lead to a transition from the (7×7) reconstruction of clean (111)Si to a carbon-induced (∛×∛)R30° structure. Above 660 °C, the silicon carbide growth starts directly on the silicon surface via three-dimensional nucleation. Below 660 °C, first a thin silicon–carbon alloy was formed by diffusion of carbon into the surface near the region with a concentration exceeding the bulk solubility in silicon.