Effect of thermally nitrided SiO2 thickness on MIS characteristics

The flatband voltage of metal-insulator-semiconductor (MIS) structures with thermally nitrided SiO2 (nitroxide) insulators has been studied as a function of the nitroxide thickness in the range of 10-60 nm, for different nitridation conditions. The most striking result is that 10-nm nitroxide films are far less susceptible than thicker ones to the degradation of the electrical properties of the starting SiO2 films induced by nitridation, as revealed by a negative shift of the flatband voltage. For nitridation cycles at relatively low temperatures (900 deg 120 min or 1000 C 60 min) the shift in the 10-nm films is practically negligible.