Electronic structure of silicon oxynitride: <i>Ab-initio</i> and experimental study, comparison with silicon nitride

Abstract

Amorphous silicon oxide SiO2, silicon nitride Si3N4, and silicon oxynitride SiOxNy are three key dielectrics in silicon devices. Implementation of nitrided oxide (oxynitride SiOxNy) as a gate dielectric in metal-oxide-semiconductor field effect transistors has been shown to significantly improve the reliability and lifetime of devices. Also, amorphous oxynitride is used as a tunnel dielectric in nonvolatile flash memory devices. The present paper is devoted to the experimental and theoretical study of silicon oxynitride electronic structure. The ionic formula of crystalline Si2N2O is deduced from the first principles. Effective masses of charge carriers in Si2N2O are calculated and compared with experimental data on tunnel injection in amorphous SiNxOy samples. Also experimental x-ray absorption and emission spectra are compared with the theoretically calculated ones.