Conduction Mechanism in Acceptor- or Donor-Doped ZrO₂ Bulk and Thin Films

The leakage current in capacitors in future electronics should be highly suppressed to achieve low power consumption, high reliability, and fast data processing. Although considerable efforts have been directed at reducing the leakage current, fundamental studies on the effects of doping on bulk and thin-film materials have rarely been conducted. Herein, we investigated the effects of doping with acceptor and donor elements on the conduction of bulk and thin-film ZrO₂ and elucidated the underlying charge conduction mechanism. In the case of bulk ZrO₂, the electrical conductivity was reliably modulated by the type of dopant element, which is highly consistent with defect chemistry theory. However, unlike in the bulk material, in acceptor- and donor-doped thin-film ZrO₂, the leakage current was suppressed, indicating that the factors determining the electrical property in thin films are different from those in bulk materials.