Effects of residual surface nitrogen on the dielectric breakdown characteristics of regrown oxides

Effects of residual surface nitrogen, remaining after stripping off oxynitrides (N/sub 2/O-grown or NH/sub 3/-nitrided oxides), on the quality of the regrown gate oxides are studied. Residual surface nitrogen is observed to reduce the breakdown field and degrade the TDDB characteristics of the subsequently grown gate oxides. Results show that oxide regrowth in N/sub 2/O, rather than O/sub 2/, can significantly suppress these undesirable effects which are ascribed to large interface roughness. A physical model, describing the roles of residual surface nitrogen and regrowth ambient, is presented to account for the differences in interface roughness among various dielectrics.<>