On ion implantation in silicon carbide

Single crystals of silicon carbide, SiC, of the 6H type were studied for their applicability in ion implantation experiments as an alternative to conventional diffusion or epitaxy for production of junctions. Rutherford scattering of 0.5 MeV He+ ions in combination with channeling showed that the crystals were of good quality. Exposure of a SiC crystal to the ambient air and temperature for 89 d leads to the formation of an oxide skin of (18 ± 5) Å thickness with an average composition of SiO1.2. Gas release measurements were performed following bombardment with 0.5 MeV Kr ions to doses between 2 × 1012 and 4 × 1015 ions/cm2. The gas was released in the temperature range 1300 to 1900 °C, the release being slightly faster for high-dose bombardments than for bombardments to lower doses. This indicates that lattice disorder in SiC anneals at fairly high temperatures. For the diffusion of the gas, an activation enthalpy of about (4.4 ± 0.3) eV was obtained.