Structure and optical properties of sapphire implanted with boron at room temperature and 1000°C

Many previous studies of ion-implanted sapphire have used gas-forming light ions or heavier metallic cations. In this study, boron (10(17) cm(-2), 150 keV) was implanted in c-axis crystals at room temperature, 500 and 1000 degrees C as part of a continuing study of cascade density and "chemical" effects on the structure of sapphire. Rutherford backscattering-ion channeling (RBS-C) of the RT samples indicated little residual disorder in the Al-sublattice to a depth of 50-75 nm but almost random scattering at the depth of peak damage energy deposition. The transmission electron micrographs contain "black-spot" damage features. The residual disorder is much less at all depths for samples implanted at 1000 degrees C. The TEM photographs show a coarse "black-spot damage" microstructure. The optical absorption at 205 nm is much greater than for samples implanted with Q N, or Fe under similar conditions. (c) 2006 Elsevier B.V. All rights reserved.