Ion-beam induced effects in of , , and orientations were studied by Rutherford backscattering spectrometry (RBS) in channeling configuration using He ions. Ar, K, or Na ions were step by step implanted at followed immediately by the RBS analysis without changing the sample environment. Defect annealing was observed during the RBS measurement, which is attributed to the electronic energy loss of the He ions. A similar effect occurs due to the electronic energy loss of the implanted ions, resulting in a reduced defect concentration between surface and profile maximum. The electronic energy loss of ions may change the charge state of defects, thus enhancing their mobility and causing defect annealing. The results suggest that within the collision cascade of individual ions in perfect sapphire only point defects are produced, the concentration of which is well reproduced by SRIM calculations taking into account suggested values of the displacement energies of and for aluminum and oxygen, respectively. The lower efficiency for point defect production measured in -oriented material can be explained by the heavily reduced visibility of Al atoms sitting on vacant octahedral sites, which are hidden in this direction. Point defect recombination is observed when the collision cascades start to overlap. Above a critical concentration point defects are altered into clusters which rapidly grow during further irradiation until a saturation is reached.
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Research Article| June 23 2006
Ion-beam induced effects at in of different orientations
C. S. Schnohr;
C. S. Schnohr, E. Wendler, K. Gärtner, W. Wesch, K. Ellmer; Ion-beam induced effects at in of different orientations. J. Appl. Phys. 15 June 2006; 99 (12): 123511. https://doi.org/10.1063/1.2204748
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