In this letter, the electrical properties of thin low‐pressure chemical vapor deposited (LPCVD) SiO2annealed in N2O ambient have been studied and compared with thermal oxide of identical thickness. It is shown that N2O‐annealed CVD oxide exhibits less interface state generation and less flatband voltage shift under constant current stress than thermal oxide. It also has excellent uniformity and comparable breakdown characteristics. An oxynitride film formation at the Si/SiO2interface by annealing in N2O is speculated to be the cause of these improvements.