MOS characteristics of N/sub 2/O-grown and NO-annealed oxynitrides

A new technique of MOSFET gate dielectric formation by rapid thermal oxidation is proposed. Gate oxynitride was first grown in N/sub 2/O and then annealed by in-situ rapid thermal NO-nitridation. This approach has the advantage of providing a higher nitrogen accumulation at the Si/SiO/sub 2/ interface than either pure N/sub 2/O oxynitride or nitridation of SiO/sub 2/ in the NO ambient. It is also applicable to a wide range of oxide thicknesses because the initial rapid thermal N/sub 2/O oxidation rate is not as self-limited as NO oxidation. The resulting gate dielectrics have reduced charge trapping, lower stress-induced leakage current and significant resistance to interface state generation under electrical stress.