NRA AND XPS CHARACTERIZATIONS OF LAYERS FORMED BY RAPID THERMAL NITRIDATION OF THIN SIO2-FILMS

Rapid thermal nitridation (RTN) of silicon dioxide films and silicon covered with its native oxide was performed at atmospheric pressure in a lamp heated furnace in NH3 at a temperature of 1000-degrees-C. Physicochemical characterizations of grown films were carried out by nuclear reaction analysis (NRA) and X-ray photoelectron spectroscopy (XPS). For the films formed by the nitridation of silicon with its native oxide, the XPS measurements, using normal and grazing emergence angles, indicate that a stoichiometric silicon nitride appears between two nitroxide (SiOxNy) films at the silicon/dielectric interface and at the surface of the dielectric. The depth profile of nitrogen in films formed by the rapid thermal nitridation of a 36 angstrom silicon dioxide was determind using chemical etching associated with NRA and estimated through the XPS technique. A homogeneous nitroxide was evidenced for the most part of the dielectric film, and a monolayer (approximately 0.7 x 10(15) atoms cm-2) of stoichiometric silicon nitride was observed at the interface between the silicon substrate and the nitroxide film.