Highly Reliable Thin Nitrided SiO₂ Films Formed by Rapid Thermal Processing in an N₂O Ambient

A novel method of nitridation of thin SiO 2 film (<10 nm) has been achieved for the first time by in situ multiple rapid thermal processing (RTP) using oxygen (O 2 ) and nitrous oxide (N 2 O) as reactants. Nitrided SiO 2 (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 SiO 2 films. However, only the SiO x N y film formed via oxidation in O 2 and following nitridation in N 2 O ambients has a large charge-to-breakdown value (>30 C/cm 2 ) and indicates a quite uniform interface ordered within at least one or two atomic layers.