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

Abstract

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 EF 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 EF 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.