Diamond formation in cubic silicon carbide

High-dose carbon implantation (3x10(17) and 1x10(18) ions/cm(2)) into cubic SiC on Si was carried out at elevated temperatures (600 to 1200 degreesC) and different dose rates (1x10(13) to 1.5x10(14) cm(-2) s(-1)). Transmission electron microscopy revealed the formation of either graphite or diamond precipitates, depending on the implantation parameters. In all cases, the diamond grains were epitaxial to the SiC lattice, while the graphite was textured. The minimum temperature for diamond formation was 900 degreesC, while graphite formed at 600 degreesC. The synthesized phase depends as well on the dose rate; graphite was formed at 900 degreesC with a high dose rate. Obviously, a critical temperature for diamond formation exists and increases with increasing dose rate. This behavior is explained by the competition between the accumulation and dynamic annealing of radiation defects in the SiC lattice, which acts as a template for diamond nucleation. Diamond grains with diameters as large as 10 nm have been observed after implantation at 1200 degreesC. (C) 2003 American Institute of Physics.