Effectiveness of N/sub 2/O-nitrided gate oxide for high-performance CMOSFETs

High-quality thin SiO/sub 2/ films are strongly needed for advanced integrated circuits such as CMOSFETs and EEPROMs. It is found that N/sub 2/O-nitrided SiO/sub 2/ film is more useful than NH/sub 3/-nitrided SiO/sub 2/ or pure SiO/sub 2/ film for obtaining high-performance CMOSFETs. However, the mechanism of hot-carrier degradation of CMOSFETs with these oxide films has not been discussed. A detailed study is reported on hot-carrier-induced degradation phenomena in nitrided SiO/sub 2/ gate CMOSFETs. It is confirmed that N atoms in gate oxide films prevent the generation of interface traps for NMOSFETs and H atoms accelerate electron trapping for PMOSFETs. Therefore, N/sub 2/O-nitrided gate oxide film free from H atoms is effective for obtaining high-performance CMOSFETs.