Embodiments of the invention provide methods for forming a hafnium material on a substrate within a processing chamber. In one embodiment, a method is provided which includes exposing the substrate within the processing chamber to a first oxidizing gas during a pretreatment process, exposing the substrate sequentially to a second oxidizing gas and a deposition gas during an atomic layer deposition (ALD) cycle, wherein the second oxidizing gas contains water and the deposition gas contains a hafnium amino compound, and repeating the ALD cycle to form a hafnium-containing layer having a thickness within a range from about 5 Å to about 300 Å. In one example, the first oxidizing gas contains an O3/O2 mixture having an ozone concentration within a range from about 5 atomic percent to about 30 atomic percent.