Charge-trapping properties of ultrathin gate oxide grown on a nitrogen-impl
anted silicon substrate were investigated using high-field Fowler-Nordheim
injection. By applying an empirical model and monitoring threshold voltage
shift due to current stress, it was found that both hole trapping and elect
ron trapping are suppressed in the nitrogen-implanted oxide. Smaller trap-g
eneration rate compared to pure SiO2 film was also noticed. Our results ind
icate that nitrogen implantation into silicon substrate before gate oxide g
rowth is an alternate way to incorporate nitrogen into the Si/SiO2 interfac
e. (C) 1999 American Institute of Physics. [S0003-6951(99)04941-4].