Titanium dioxide (TiO₂)-based gate insulators

Titanium dioxide has been deposited on silicon for use as a high-permittivity gate insulator in an effort to produce low-leakage films with oxide equivalent thicknesses below 2.0 nm. Excellent electrical characteristics can be achieved, but TEM and electrical measurements have shown the presence of a low-resistivity interfacial layer that we take to be SiO₂. The leakage current follows several mechanisms depending on the bias voltage. Reasonably good agreement has been seen between current-voltage measurements and a 1D quantum transport model.