Samples of α-quartz were implanted with 20keV H2+ ions to a fluence of 5 x 1016/cm2 at a target temperature of 77K. Rutherford back-scattering, in the channelling geometry, revealed that an amorphous surface layer of 1.54 x 1018 atoms/cm2 formed under these conditions. Resonant nuclear reaction analysis, employing the 1H(15N,αγ)-resonance at a beam energy of 6.385MeV was used to measure the implanted H profiles. The samples were then annealed (300 to 950C, 1h, air). After annealing, the same techniques were used to study alterations in the H profile, and the amorphous layer, which were induced by heat treatment. In contrast to observations involving alkali ions, no epitaxial re-growth could be detected even after annealing at 950C. No changes in the H profile were again observed below about 450C while, at about 600C, almost all of the H had left the sample. This behaviour was consistent with the results obtained for other alkali-ion implantations in that H, being the lightest and smallest group-I atom, became mobile at the lowest temperature. The results also confirmed the observed trend that the quality of the re-grown layer decreased with decreasing atomic number of the implanted species.

Diffusion of Hydrogen Implanted into α-Quartz during Air Annealing. W.Bolse, M.Gustafsson, F.Harbsmeier, F.Roccaforte: Nuclear Instruments & Methods in Physics Research B, 2000, 161-163, 641-5