Physical characterization of ultrathin silicon oxynitrides grown by Rapid Thermal Processing aiming to MOS tunnel devices

Oxynitrides were grown in a homemade Rapid Thermal Processor (RTP) using a low mass quartz carrier, to obtain thin oxynitrides over large areas of 3 inches silicon p-type wafers. Layers with thickness varying from 0.97 to 2.39 nm with uniformity better than 0.4%, were obtained at 700 and 850°C, in a mixed ambient of nitrogen and oxygen (4N2:3O2 in volume). The nitrogen concentration was obtained with the aid of X-ray photoelectron spectroscopy (XPS) and was 0.6 at%. On the other hand, the Si/O ratio in the oxynitride was approximately 1.9, indicating an almost stoichiometric SiO2 with a small amount of nitrogen. In addition, using the 16O(α, α) elastic-scattering signal at 3.039MeV, the planar concentration of oxygen was 5.5×1015cm2 for the oxynitride grown at 850°C during 40s.