THE STUDY OF DAMAGE PROFILES IN MEV SI+-IMPLANTED LINBO3 CRYSTALS BY RUTHERFORD BACKSCATTERING AND OXYGEN RESONANCE SCATTERING

摘要

X-cut LiNbO3 crystals were implanted with 1.0 MeV Si+ using doses ranging from 3X10(14) to 2X10(15) ions cm(-2). The 3.3 MeV He2+ Rutherford backscattering/channelling technique was used to analyse the implanted LiNbO3 crystals. The spectra obtained demonstrate that the scattering peaks of the elastic resonance of 3.045 MeV He-4 with O-16 show a broadened half-width. With increasing implant dose, the damage peak of the Nb atoms shifts to the lower-energy side, and the apparent half-width of the resonance peak becomes narrower. The results are explained as being due to the different reduction of stopping power in a channelling direction for He ions after different dose implantations. The reduction of the stopping power for channelled ions can be deduced from the different half-widths of the resonance scattering peaks for spectra corresponding to aligned and random beam directions. The damage depth distributions for implanted LiNbO3 crystals were obtained after considering the corresponding reductions of channelled stopping power. The result shows that the damage profiles for lower dose implantation were shallower than these predicted by TRIM'90 (Transport of ions in Matter 1990), but they were in good agreement with our calculation. [References: 18]