Group IVB metal oxides high permittivity gate insulators deposited from anhydrous metal nitrates

Abstract

The electrical performance of column IVB metal oxide thin films deposited from their respective anhydrous metal nitrate-precursors show significant differences. Titanium dioxide has a high permittivity, but shows a large positive fixed charge and low inversion layer mobility. The amorphous interfacial layer is compositionally graded and contains a high concentration of Si-Ti bonds. In contrast, ZrO2 and HfO2 form well defined oxynitride interfacial layers and a good interface with silicon with much less fixed charge. The electron inversion layer mobility for an HfO2/SiOxNy/Si stack appears comparable to that of a conventional SiO2/Si interface.