Abstract
Ultrathin dielectrics, oxides and oxynitrides were grown using microwave afterglow oxygen and N 2 O plasma at low temperature. N 2 O plasma annealing and pretreatment improved the breakdown properties of O 2 plasmaoxides. From secondary ion mass spectroscopy (SIMS) analysis, nitrogen was found to be incorporated into oxideseffectively by this low-temperature method. Nitrogen content was highest at the oxide surface and decreasedtoward the oxide/Si interface. This indicates a nitridation mechanism different from the conventional N 2 O gas annealing or oxidation processes. The relationships among interface state densities, tunneling current and nitrogenprofiles were also investigated by C-V and I-V measurements. © 1995 The Japan Society of Applied Physics.