Wide Spectrum Optical Properties for HfO₂Films

Abstract

HfO2 thin films are deposited on K9 glass by Kaufman ion source assisted electron beam evaporation. The X-ray diffraction (XRD) results show that the films presented monoclinic phase. Spectroscopic ellipsometer SE850 is used to test elliptic partial parameters in 280~2500 nm waveband， and Cauchy index model, Tauc-Lorentz model, Forouhi-Bloomer model, Sellmeier-Transparent model are used to analyze the ellipsometric data with considering rough surface layer and interface layer, and optical parameters are obtained from ultraviolet (UV) to near-infrared (NIR) band. The fitting results show the Tauc-Lorentz model is the best model to describe the HfO2 film optical properties (MSE 0.57). Thin films transmittance are measured by Lumda 950 spectrophotometer and HfO2 films optical band gap are calculated (~5.40 eV).