Electrical properties of composite gate oxides formed by rapid thermal processing

The rapid thermal processing, involving pre- and post-oxide deposition, improves the characteristics of composite gate oxides which act as gate dielectrics. The composite structure originating from pre-oxidation before the oxide deposition, and post-deposition oxidation in O2 and N2O, has low defect density and high mobility. N2O annealed oxides have high resistance towards hot carriers, low charge trapping capacity and low interface trap densities. The existence of nitrogen at the interface and the decreased interaction between nitrogen and hydrogen are responsible for the improved properties.