NITROGEN DEPLETION DURING OXIDATION IN N2O

The incorporation of nitrogen in oxides has been studied after furnace oxidation in N2O at 900 degrees C. We observe that nitrogen is remove d from the oxide bulk during oxidation in N2O, while simultaneously ni trogen is incorporated at the growing Si-SiO2 interface. This results suggests that nitrogen incorporation involves a dynamic equilibrium be tween competing processes which causes both nitrogen incorporation and depletion. A chemical model for nitrogen removal is proposed based on a reaction with NO. Reaction energies, estimated from semiempirical q uantum-mechanical calculations, support the proposed model. (C) 1995 A merican Institute of Physics.