Abstract: The characteristics of ZnS-SiO_2 dielectric film were studied by using AFM, XRD, TEM, UV/Vis/NIR
spectrometer, and spectroscopic ellipsometer methods. It was indicated that the as-deposited ZnS-SiO₂ film is amorphous and has Straski-Krastanov type
growth characteristic. The surface of the ZnS-SiO₂ film is very smooth. The grain size of the ZnS-SiO₂ film is very small, around 2～10nm. The
transmissivity of the ZnS-SiO₂ film is large and the extinction coefficient is very small, which are beneficial to reduce the loss of laser power. The
refractive index of the ZnS-SiO₂ film is large and the recording layer can be protected very well.

Key words: ZnS-SiO₂, dielectric layer, phase-change optical disk