Native defect formation and migration in monoclinic zirconium dioxide

We investigate native defect formation and migration in monoclinic zirconium dioxide using first-principles calculations based on density functional theory. The formation energies and transition levels of the native defects can be accurately described by employing nonlocal B3LYP hybrid functional. This methodology overcomes the band-gap problem in traditional functionals and renders the approach more predictive. By band alignments between the GaAs and the ZrO2, we are able to determine the position of defect levels in the GaAs relative to the ZrO2 band gap and assess how they will affect the device performance. In addition, we also investigate diffusions of neutral and charged defects in ZrO2. It is found that Oi is the one with the lowest migration barrier. Hence, this point defect is identified most dangerous in monoclinic ZrO2 within the context of high-k gate dielectric application.