Stabilization of the tetragonal phase in ZrO<sub>2</sub> thin films according to ozone concentration using atomic layer deposition

Abstract

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.