Ion implantation of N into Si and SiO2/Si in the 1-1000 eV energy range for gate dielectric fabrication

We report on N doses and profiles in Si and in ultrathin SiO₂ films on Si nitrided by plasma or ion beam processing in the 1-1000 eV energy range. Accurate elemental quantification was performed by nuclear reaction analysis, and elemental profiling with subnanometric depth resolution was achieved by narrow nuclear resonance profiling or medium energy ion scattering. Heavy and shallow N incorporation was observed, with up to 0.7 N/(N+O) and peak N concentrations at 2 nm and less from sample surface. Device-quality films were produced with post-nitridation annealing in O₂, as indicated by C-V and I-V measurements