Electrical properties and reliability of MOSFET´s with rapid thermal NO-nitrided SiO2 gate dielectrics

This paper reports on the performance and hot carrier reliability of N- and P-channel MOSFET´s with oxynitride gate dielectrics fabricated by rapid thermal nitridation (RTN) of thermally grown SiO₂ in pure nitric oxide (NO) ambient. It is found that current drivability of N-channel MOSFET´s increases with NO-nitridation of SiO₂. A significant enhancement in high field electron mobility is also observed with increasing NO-nitridation. P-channel MOSFET´s with NO-nitrided SiO ₂ gates show somewhat lower current drivability and hole mobility compared to SiO₂ for both low- and high-V_g. Both N- and P-channel MOSFET´s with NO-nitrided oxides show excellent immunity to channel hot carrier degradation. The improvement in hot-carrier reliability is attributed to the efficient incorporation of nitrogen in the dielectric through NO-nitridation. A 1000°C, short 10-second NO-anneal was found to be the optimum nitridation condition since, compared to control oxide devices, these devices showed comparable electron and hole mobility but significantly enhanced hot-carrier immunity