Ultrathin dielectrics (<4 nm) were prepared by both growing and annealing in a nitric oxide (NO) ambient, using rapid thermal processing at different temperatures for various lengths of time. Compositions and residual nitrogen contents in various dielectrics were studied using x‐ray photoelectron spectroscopy (XPS). The XPS depth profiles show that the nitrogen distribution of NO grown films is different from those that are NO‐annealed (an initially grown pure oxides annealed in NO), N2O‐grown and N2O‐annealed (an initially grown oxide annealed in N2O) oxynitrides. The nitrogen distributes evenly throughout the dielectric with an atomic percentage of around 5.4 at. % for the NO‐grown sample, while the nitrogen concentration is lower at the dielectric surface and piles up at the dielectrics/silicon interface with a peak of 5 at.% for the NO‐annealed oxides. Deconvolution of Si 2p and N 1s XPS spectra has been used to study the bond structures. Both Si≡N and Si‐N=H2bonds have been found in the NO‐grown and NO‐annealed films, the later one is believed to be introduced by hydrogen impurities present in the NO gas or growth environment. ©1995 American Institute of Physics.