Role of implantation temperature on residual damage in ion-implanted 6H-SiC

The optical and structural properties of ion-implanted 6H-SiC single crystals were investigated for samples implanted with 370 keV Si-28 ions to doses ranging from 5 x 10(13) to 1 x 10(16) cm(-2) and at irradiation temperatures ranging from 20 to 600 degreesC. Rutherford backscattering spectrometry channelling (RBS/C) showed that the dynamic recovery of the induced-damage layer increases with irradiation temperature. The final disorder determined from RBS/C as a function of implantation temperature was modelled in terms of a thermally activated process which yielded an activation energy of 0.08 eV. Defect distributions are found to shift to greater depths with increasing implantation temperature and dose. Some defects are even found farther than the accessible range of the implanted ions. RBS/C data on high-temperature implantations also suggests that defect complexes are created at high doses in addition to the point defects that are still stable at high temperature. A decrease in Raman intensity of implanted samples relative to that of crystalline samples was observed and correlated with an increase in optical absorption near the wavelength of the laser pump (514.5 nm).