Dielectric properties of Ta2O5 films grown on silicon substrates plasma nitrided in N2O

C–V characteristics and leakage currents of metal-insulator-silicon structures containing insulating film composed of thermally grown Ta₂O₅ and ultrathin SiO_xN_y layer grown in N₂O plasma were studied. Leakage in the structures is explained by tunneling in SiO_xN_y layer and Poole–Frenkel internal field assisted emission in Ta₂O₅. Theoretical calculations were made by known theoretical expression, while using fitted values of the thickness of SiO_xN_y, defect related constants for Ta₂O₅, and compensation degree r=1 for Ta₂O₅. For positive gate biases, tunneling of electrons from the silicon conduction band through SiO₂ is considered, while for gates negatively biased, tunneling of holes from the silicon valence band. In the early stage of nitridation barriers for injection decreases rapidly, then much slower. The thickness of the SiO_xN_y layer increases slowly with the nitridation time, as a result of the created barrier against diffusion of silicon atoms created by nitrogen incorporated at the interface between the silicon and oxide SiO_xN_y layer. PACS 73.40.Qv; 73.50.-h; 73.61.-r An erratum to this article can be found at .