TEMPERATURE-INDUCED PHASE DEVELOPMENT IN TITANIUM-IMPLANTED SILICON-CARBIDE

Silicon carbide has been implated with titanium at three different dos es. Transmission electron microscopy and Rutherford back-scattering (R BS) have been used to follow changes resulting from post-implantation heat treatment. The as-implanted layer is amorphous, and after a low t emperture anneal a fine, non-equilibrium titanium carbide precipitate appears in the amorphous matrix. At higher temperatures, first the ter nary phase Ti3SiC2 and the SiC crystallizes. RBS measurements show tha t the initial Gaussian titanium concentration profile changes near the ternary phase precipitation temperature, developing side peaks at the area of maximum initial concentration gradient. Thermodynamic and kin etic factors in the observed phase development are discussed, and the need for a metastable phase diagram is considered.