Gate quality ultrathin (2.5 nm) PECVD deposited oxynitride and nitrided oxide dielectrics

Ultrathin oxynitride using plasma assisted deposition mas evaluated against thermal oxide and nitrided thermal oxide as an alternative direct tunnelin g gate dielectric to thermal oxide in the 2.5-nm regime. The oxynitride sho wed an enhanced high field effective mobility relative to the thermal oxide although the low field mobility was slightly depressed. The N2O nitrided o xide showed an enhanced high field effective mobility with no degradation i n low held mobility, The interface state density of the oxynitride was equi valent to that of the thermal and nitrided thermal oxides; a very welcome o bservation for this deposition chemistry and anneal conditions.