MOBILITY OF HG+ AND BR+ IMPLANTED IN QUARTZ

Both Hg+ and Br+ were implanted in quartz (SiO2) 7 years ago. The mobi lities of the implanted Hg+ and Br+ at room and higher temperatures ar e investigated by Rutherford backscattering of 2.1 MeV He2+ ions. The results show that both Hg+ and Br+ are still immobile at room temperat ure after 7 years. The depth distributions of Hg+ agree well with thos e calculated by the transport of ions in matter program (TRIM'90). How ever, for the case of Br+ the mean projected range is shallower than t he TRIM-90 prediction with increasing implantation energy. It is found that 300 keV Hg+ and 250 keV Br+ are mobile after 600 degrees C and 5 00 degrees C annealing respectively. Both diffusion and evaporation du ring annealing are observed.