Effects of reoxidation on band alignment in N-incorporated SiON films as a function of sequential thermal annealing in NO and NH3

The effects of reoxidation on the band structure of N-incorporated SiON films were investigated as a function of thermal treatment in NO and NH3. Reoxidation-associated changes in band gap and valence band offset of the N-incorporated SiON films prepared by sequential thermal annealing in both NO and NH3 were less than those observed for the nitrided film prepared by thermal annealing in only NH3. The differences in band-alignment characteristics of the nitrided films that resulted from use of different nitridation methods were strongly related to the depth distribution of N and the chemical states of N bonded to Si.