MODIFIED STRUCTURE OF SAPPHIRE WITH V-51 ION-IMPLANTATION FOLLOWED BYTHERMAL ANNEALING

Damage growth and its recovery behavior are compared in sapphire (0001 ) samples implanted with V-51(+) at low temperatures and room temperat ure by employing Rutherford Back-Scattering (RBS)/channeing and RBS/O- 16(d, alpha)N-14 nuclear reactions/ channeling techniques. The in-situ analysis using a dual beam analysis system indicates that the damage growth at room temperature (RT) is not the simple accumulation of the same defect-profile at the initial stage of implantation. The damage i ntroduction at low temperature (36 K) induces the amorphous layer afte r 7.4 x 10(14) cm(-2) implantation. The depth amorphized is about 60% of the projected range and rather close to the peak position of defect -profile at the initial stage of RT implantation. The re-growth of amo rphous layer is caused more easily in heavily implanted sapphire. The redistribution of implanted V-51 atoms into surface results in the coh erent precipitation of vanadium oxide. The samples implanted at RT cha nge into the mixed oxide after annealing through the preferential dist ortion of the oxygen sublattice. (C) 1998 Elsevier Science S.A. All ri ghts reserved.