Physical models for predicting plasma nitrided Si-O-N gate dielectric properties from physical metrology

Using simple physical models, specific relationships between parameters measured by X-ray photoelectron spectroscopy (XPS) and those measured on MOS transistors are described for silicon oxynitride gate dielectrics prepared by plasma nitridation. Correlations are established between the equivalent oxide thickness (EOT) and gate leakage current and the nitrogen anneal dose and physical thickness as measured by XPS. These correlations, from devices in the 10 to 13 Angstrom EOT range, allow accurate estimates of electrical thickness and leakage without device fabrication, enabling both development and process monitoring for sub-130-nm node gate dielectrics.