Stabilization of the tetragonal phase in ZrO2 thin films according to ozone concentration using atomic layer deposition

In this study, we investigated the crystallographic and electrical properties of ZrO2 thin films prepared by an ozone-based atomic layer deposition process. Cyclopentadienyl tris(dimethylamino) zirconium [CpZr(NMe2)(3)] was used as the Zr precursor, and O-3 was used as the reactant. ZrO2 films were produced using O-3 in various concentrations from 100 to 400 g/m(3). These thin films were used to fabricate metal-oxide-semiconductor capacitors, whose electrical properties were evaluated and correlated with crystallographic analysis. As the O-3 concentration increased, the tetragonal phase of the ZrO2 film stabilized and the dielectric constant improved. However, the leakage current density characteristics concurrently deteriorated due to the high concentration of O-3, increasing the number of grain boundaries in the ZrO2 film by increasing crystallinity. Thus, the concentration of O-3 can control the number of OH groups of the ZrO2 film, affecting the device characteristics.