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

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.