Zirconium dioxide($ZrO_2$) thin films have been deposited by chemical vapor deposition technique involving the application of gas mixtures of $ZrCl_4$, $CO_2$, and $H_2$ onto silicon wafers. The relationships between the deposition rate and various reaction parameters such as the deposition time, the gas flow rate, the deposition temperature, and the composition of reactant gases were studied. The film was identified as nearly stoichiometric monoclinic $ZrO_2$, using XPS analysis, infrared transmission, and XRD. $ZrCl_4$ is the only species as zirconium donor at the result of thermodynamic calculation. The CVD of $ZrO_2$ is thermally activated process and deposition mechanism changes from mass transport controlled process to surface chemical reaction controlled process with increasing total flow rate at 973K. The apparent activation energy is about 19Kcal/mole at surface chemical reaction controlled region. The dependence of the deposition rate on the reactant gas composition is affected by the variation of the relative content of the zirconium donor and oxygen donor. At a low $ZrCl_4$ mole fraction, the deposition rate increases with the $ZrCl_4$ mole fraction; however, at higher $ZrCl_4$ mole fraction than $3.0\times10^{-2}$ the deposition rate is mainly influenced by the $H_2O$-forming reaction between $CO_2$ and $H_2$.
