Embodiments provided herein describe high-k dielectric layers and methods for forming high-k dielectric layers. A substrate is provided. The substrate includes a semiconductor material. The substrate is exposed to a hafnium precursor. The substrate is exposed to a zirconium precursor. The substrate is exposed to an oxidant only after the exposing of the substrate to the hafnium precursor and the exposing of the substrate to the zirconium precursor. The exposing of the substrate to the hafnium precursor, the exposing of the substrate to the zirconium precursor, and the exposing of the substrate to the oxidant causes a layer to be formed over the substrate. The layer includes hafnium, zirconium, and oxygen.