Prediction of the terminations and Miller planes of the tetragonal zirconia thin films as a gate dielectric layer in integrated-circuit industry

In this paper, we investigate the structures and insulating characters of the tetragonal zirconia (t-ZrO₂) thin films with various possible terminations within the lower-index Miller planes (001) and (100). It is found that, firstly, a shift towards higher energy region makes the valence band of the OO-terminated thin films of the (001) Miller plane of t-ZrO₂ cross the Fermi level E_F and thus are unusable as a gate dielectric oxide in integrated-circuit (IC) industry because of large-leakage current. Secondly, a new splitting state presented just below the bottom of conduction band, and the Fermi level E_F drops between them, which imply that the Zr-terminated thin films of the (001) Miller plane of t-ZrO₂ are also unusable as a gate dielectric oxide in IC industry because of large leakage current. Thirdly, the insulating character disappears completely for Zr + OO-terminated thin films of the (001) Miller plane of t-ZrO₂ and thus is also unusable as a gate dielectric oxide in IC industry because of metal character. Fourthly, the insulating character is maintained for the ZrO₂-terminated thin films of the (100) Miller plane and thus is usable as a gate dielectric oxide in IC industry.