Out-diffusion of hydrogen from hydrogen plasma-processed oxygen-implanted silicon

Abstract

Hydrogen gettering and its out-diffusion from implantation-disturbed buried layers formed in oxygen-implanted silicon, annealed and subsequently treated in hydrogen plasma, have been investigated. Energy and doses of implanted oxygen ions were 200keV and 1×1017cm−2, respectively. After implantation Si:O samples were annealed at up to 1573K, also under enhanced hydrostatic pressure, up to 12.3kbar. Depending on processing conditions, disturbed buried layers, containing vacancy-like and other defects, SiO2−x clusters and/or precipitates, were formed. To produce hydrogen-enriched silicon structures, Si:O,H, with hydrogen accumulated within implantation-disturbed buried layers, Si:O samples were treated in hydrogen plasma. Out-diffusion of hydrogen from Si:O,H samples was investigated after annealing at 723K and 973K under atmospheric pressure. Depth profiles of oxygen and hydrogen were determined using secondary ion mass spectroscopy; X-ray reciprocal space mapping was applied for defect structure determination. Part of hydrogen remains to be present at surface and, especially, within implantation-disturbed areas even after annealing of Si:O,H at 973K.