ION-IMPLANTATION INTO HEATED SILICA SUBSTRATES

The final ion distribution of copper, gallium and silver ion implants into heated silica substrates has been measured using Rutherford backscattering spectroscopy (RBS). The implantation parameters were identical for each series of implants: 55 keV ion energy and an implanted dose of 6.4 x 10(16) ions/cm2. However, the temperature of the substrate was varied, with implants being done at room temperature (RT), 373 K, 498 K, 623 K and 873 K; a gallium implant was also done at 1123 K. With increasing temperature the ion distributions became increasingly non-Gaussian and the gallium profiles became bimodal above 498 K. The displacement of the substrate atoms was also measured with RBS. Below 873 K it was found that the substrate atoms were significantly displaced by the implanted ions. However at 873 K the substrate recovers to the unimplanted state with no evidence of atomic displacement or removal, despite the presence of the implanted ions.