Characteristics of the synthesis of β-SiC by the implantation of carbon ions into silicon

Abstract

From studies of the IR absorption of SiC layers formed by the implantation of carbon ions into silicon, the degree of the incorporation of the implanted carbon atoms into β-SiC was calculated as a function of the dose between 2 × 10 17 and 2× 10 18 cm −2 at 100 keV, of the annealing temperature up to 1200°C and of the substrate temperature during implantation up to 600°C. When the dose is less than 6×10 17 cm −2 at 100 keV, almost all the implanted carbon atoms are incorporated into β-SiC which, however, exists as SiC grains in silicon. When the dose is increased, carbon atoms tend to form clusters in silicon and diffuse very little below an annealing temperature of 1200 °C. As a result, carbon atoms in excess of the stoichiometric concentration are not incorporated into β-SiC by annealing below 1200 °C. Implantation at an elevated temperature led to a reduction in the temperature required for the synthesis of SiC. Implantation at 600°C, for example, was equivalent to an annealing temperature of 1100 °C after room temperature implantation.