Oxidized silicon nitride films in thin insulator MIS structures

Thin oxynitride layers in the range 50-100 Å thickness were grown by the oxidation of a thermally nitrided silicon surface. The obtained films were chemically investigated by Auger analysis and chemical etching measurements. Independent measurements of the surface states density and surface generation velocity show that similar interface characteristics to those of standard oxides are achieved by adequate processing. Mobility and trapping effects were investigated in fully processed polysilicon gate n-channel transistors. While the mobility values are comparable to those obtained in standard oxide devices, the oxynitride layers show a significantly improved stability against charge injection.