Reliability Properties of Ta2O5 Films Grown on N2O Plasma Nitrided Silicon

Abstract

Plasma nitridation of the Si substrate prior to the thermal growth of Ta ₂ O ₅ improves significantly the reliability properties of the insulating film. Stress induced leakage currents are reduced for several orders of magnitude. Based on the physical model used in the analysis, the improvement is explained by the impeded consumption of the oxynitride interfacial layer, due to the incorporation of nitrogen atoms at the Si interface, making it more resistant against the stress degradation. Plasma nitridation improves the dielectric properties by increasing the dielectric constant of the interfacial layer, thus reducing the equivalent oxide thickness