HIGH-ENERGY IRON-ION IMPLANTATION INTO SAPPHIRE

Sapphire specimens of c-axis orientation were implanted at room temperature with iron ions at energies of 1.2 and of 2 MeV to various fluences up to 8 x 10(16) cm-2. The damage induced by the implantations was assessed by Rutherford backscattering spectrometry in random and channeling geometries. Dechanneling in both sublattices was observed to saturate for all implantation conditions. Disorder in the aluminum sublattice was found to increase with depth at a significantly slower rate than in the oxygen sublattice. In the oxygen sublattice, a relative yield chi of 0.80 +/- 0.11 was attained at a depth of 0.1-mu-m and remained constant up to the measured depth of 0.45-mu-m. In the aluminum sublattice, the disorder increased with depth and the dechanneling asymptotically approached chi = 0.70 +/- 0.04 at 0.45-mu-m. These results are discussed and compared with those for shallower Fe implantations obtained by other researchers.