Melt-interface mechanism for generation of silicon carbide microdefects in silicon

Abstract

Abstract Two-phase hypereutectic solidification, involving growth of SiC particles nucleated on the solid-liquid interface, is examined as a mechanism for incorporating very high levels ( ⩾ 20 ppma) of carbon in silicon crystals grown from the melt. Calculations indicate that particles may attain radii of up to 5–10 nm under certain growth conditions. It is proposed that these “nanoprecipitates” are the microdefects which have been suggested to act as gettering centers in carbon-rich silicon sheet prepared for photovoltaic applications by the Edge-defined Film-fed Growth (EFG) technique.