LOW-ENERGY N-15 AND N-14 IMPLANTATION IN CHROMIUM ANALYZED BY NRA AND RBS

The physical results of implantation processes are dependent on several interconnected parameters. For the nitrogen implantation into chromium the interdependence of fluence, dose and nitrogen profiles was investigated. Thin PVD chromium films, evaporated on polished glassy carbon and crystalline silicon substrates, were implanted with 30 keV ions (N-15 and N-14) in a fluence range from 10(17) to 10(18) at./cm2. The nitrogen depth distributions were measured by using the nuclear resonance reaction N-15(p, alphagamma)C-12 at E(res) = 429 keV (NRA). Information about ion beam induced effusion and diffusion of N-15 was gained from the implantation of N-14 in addition to preimplanted nitrogen (N-15). It was observed that N-15 was displaced and recoiled into greater depths of the sample. RBS measurements with He-4+ ions were used to analyse the sample composition and the release of chromium (sputtering yield). Furthermore, the results of the NRA measurements were compared with RBS measurements.