High quality interpoly dielectrics deposited on the nitrided-polysilicon for nonvolatile memory devices

High quality interpoly dielectrics have been fabricated by using NH3 and N2 O nitridation on polysilicon and deposition of tetra-ethyl-ortho-silitate ( TEOS) oxide with N2O annealing. The surface roughness of polysilicon is imp roved and the value of weak bonds is reduced due to nitrogen incorporation at the interface, which improves the integrity of interpoly dielectrics, Th e improvements include a higher barrier height, breakdown strength, and cha rge-to-breakdown, and a lower leakage current and charge trapping rate than counterparts. It is found that this method can simutaneously improve both charge-to-breakdown (up to 20 C/cm(2)) and electric breakdown field (up to 17 MV/cm).