HIGHLY RELIABLE THIN NITRIDED SIO2-FILMS FORMED BY RAPID THERMAL-PROCESSING IN AN N2O AMBIENT

A novel method of nitridation of thin SiO2 film (< 10 nm) has been achieved for the first time by in situ multiple rapid thermal processing (RTP) using oxygen (O2) and nitrous oxide (N2O) as reactants. Nitrided SiO2 (SiO(x)N(y)) films, in which nitrogen piles up about 5 at% at the SiO(x)N(y)/Si interface, showed smaller densities of electron and hole traps in high-field stressing as compared to those of pure SiO2 films. However, only the SiO(x)N(y) film formed via oxidation in O2 and following nitridation in N2O ambients has a large charge-to-breakdown value (> 30 C/cm2) and indicates a quite uniform interface ordered within at least one or two atomic layers.