A physical model for implanted nitrogen diffusion and its effect on oxide growth

Nitrogen has been used to control oxide thickness, allowing process engineers to have multiple gate oxide thickness in the same process. New models have been developed for nitrogen behavior in silicon and its interaction with oxide growth. The diffusion model is based on ab-initio results, and is compared to experimental results at two temperatures. The oxide reduction model is based on the diffusion of nitrogen to the surface. The surface nitrogen is coupled to the surface reaction rate of oxygen and silicon to moderate the growth of the oxide.