In this paper we present the investigation of high-k dielectrics in a metal-insulator-metal structure. We show the physical and electrical properties of ZrO₂ and Sr_xZr_{(1-x )}O_y grown through sputter deposition. Uncontrolled crystallization of ZrO₂ during the growth into a mixture of different phases was observed. As a consequence, the k-value was suppressed. Stabilization of the amorphous phase of the as grown films could be achieved by the admixture of SrO. This enabled controlled crystallization into a single phase after performing post-deposition annealing. The k-value of the annealed Sr_xZr_(1-x)O_y was determined to be 33.