Characterization of Hafnium-Zirconium-Oxide-Nitride films grown by ion beam assisted deposition

Hafnium-Zirconium-Oxide-Nitride (Hf1−xZrxO1−yNy) films are prepared by ion beam assisted deposition on p–Si and quartz substrates with a composite target of sintered high-purity HfO2 and ZrO2. The thermal stability and microstructure characteristics for Hf1−xZrxO1−yNy films have been investigated. EDS results confirmed that nitrogen was successfully incorporated into the Hf1−xZrxO2 films. XRD and Raman analyses showed that the Hf1−xZrxO1−yNy films remain amorphous after 1100 °C under vacuum ambient, and monoclinic HfO2 and ZrO2 crystals separate from Hf1−xZrxO1−yNy films with a increase of the annealing temperature up to 1300 °C. Meanwhile, the Hf1−xZrxO1−yNy films can also effectively suppress oxygen diffusion during high temperature annealing. AFM measurements demonstrated that surface roughness of the Hf1−xZrxO1−yNy films increase slightly. Then the optical properties of the samples were observed in the ultraviolet–visible range at room temperature. The variation in Eg from 5.64 to 6.09 eV as a function of annealing temperature has also been discussed briefly.

► Hf1−xZrxO1−yNy films have been grown by using ion beam assisting deposition. ► The Crystallization temperature of the films is more than 1100 °C. ► Nitrogen reduces diffusion rate for the initial phase separation. ► The highest Eg of 6.09 eV was obtained after annealing at 900 °C.