New Insights into Tunneling Current through Oxynitride/Oxide Stack for MOSFETs

A first principles study of silicon oxynitride shows that the defect-like levels near the conduction and valence band will be introduced into the bandgap while incorporating nitrogen into silicon dioxide. It has also been shown that the tunneling current through oxynitride/oxide stack for MOSFETs assisted by defect-like levels near the conduction band will be dominant at high field and the direct tunneling current will be dominant at low field. This work gives an insight about the reason on smaller tunneling current at low field compared to the tunneling through pure silicon dioxide , which is that the effective masses give a large contribution to reducing the direct tunneling current than simply increasing physical thickness does