Studying the insulating characters of cubic ZrO

In this paper, we exam the insulating characters of cubic ZrO 2 (c-ZrO 2 ) slabs with various possible terminations within three lower index Miller planes (001), (110) and (111). It is found that, firstly, a shift towards higher energy region makes the valence bands of both the O-terminated slabs of (001) plane and OO-terminated slabs of (111) plane of c-ZrO 2 cross the Fermi level (E F ) and thus unusable as a gate dielectric oxide. Second, a new splitting state presented just below the bottom of conduction band and crossed the E F imply the Zr-terminated slabs of both (001) and (111) planes of c-ZrO 2 are also unusable as a gate dielectric oxide. Thirdly, combining above two mechanisms together makes the insulating character disappear completely for Zr + O-terminated slabs of the (001) plane of c-ZrO 2 and thus unusable as a gate dielectric oxide. Fourth, the insulating character is maintained for both the ZrO 2 -terminated slabs of the (110) plane and the O-terminated slabs of the (111) plane of c-ZrO 2 and thus usable as a gate dielectric oxide. We hope these theoretical predictions can provide a guide in fabrication and application of ZrO 2 gate dielectric material. The optimized structures of 11L-(001)-O, 9L-(001)-Zr, 10L-(001)-Zr+O, 9L-(110)-ZrO 2 , 19L-(111)-Zr, 17L-(111)-OO, 15L-(111)-O, 13L-(111)-Zr and 11L-(111)-OO slabs of cubic ZrO 2 . Display Omitted • Insulating characters of c-ZrO 2 slabs with 9 terminations within (001), (110), (111) planes. • A higher energy region shift makes valence bands of both (001)-O and (111)-OO slabs cross E F . • A new splitting state of both (001)-Zr and (111)-Zr slabs crosses the Fermi level E F . • Above two mechanisms make the insulating character disappear completely for (001)-Zr + O slabs. • Both (110)-ZrO 2 and (111)-O slabs are usable as a gate dielectric oxide.