Rutherford backscattering and channelling studies of buried nitride structures directly produced by high intensity ion implantation of nitrogen into silicon

Recent work on buried nitride structures has shown that by using the so-called High Intensity Ion Implantation (HIII), it is possible to produce stoichiometric layers of Si3N4. Under appropriate conditions of flux, dose and temperature, the HIII of nitrogen appears to have similarities to oxygen implantation in that the composition at the peak of the implant profile saturates at the stoichiometric ratio for Si3N4 while maintaining good crystalline quality in the silicon overlayer. Buried nitride structures have been directly formed by high energy (1 MeV mol-1) HIII of molecular nitrogen in heat sunk silicon substrates at doses ranging from 7 x 1017 to 2.1 x 1018 cm-2 and temperatures up to 300oC. Rutherford backscattering and channelling analysis of the as-implanted samples was undertaken to evaluate the distributions of the implanted nitrogen atoms and the extent of radiation damage in the silicon overlayers. It has been found that the resulting structures depend strongly on the dose rate, implant dose, temperature and manner of beam heating. (author)