Characteristics of Ce-Doped ZrO₂ Dielectric Films Prepared by a Solution Deposition Process

The microstructural and electrical properties of sol-gel deposited ultrathin Zr_1-x Ce_x O₂ films with different Ce contents (x=0, 0.1, 0.3, and 0.5) were studied using various characterization tools. Ce doping reduced the crystallization (densification) temperature and increased the dielectric constant of the Zr_1-x Ce_x O ₂ film. There was no degradation of the hysteresis characteristics, and a systematic negative shift in the flatband voltage was observed by incorporating Ce atoms. Leakage current measurements showed no detrimental effects of Ce doping up to x=0.5, and the conduction mechanism analyses revealed that the Zr_1-x Ce_x O₂ films follow a Poole-Frenkel (PF) conduction, exhibiting a systematic increase in the linear slope of the PF plot possibly due to the decrease in dielectric trap sites with increasing Ce content.