Abstract
Aiming to obtain high density of directly overwritable optical discs, the optical phase change material has been studied. Ag-In-Sb-Te multinary alloy is one of the most investigated materials as phase change recording media. In this work, all films were deposited by R. F. magnetron sputtering. Ag-In-Sb-Te recording film was sandwiched between two ZnS 80 – SiO2 20 at % layers. And the layer structure of the phase change disc used in the experiment is polycarbonate substrate / ZnS:SiO2 115 nm / Ag-In0Sb-Te 20 nm / ZnS:SiO2 15 nm / Al 120 nm which is determined by optical and thermal simulation.The composition of the Ag-In-Sb-Te alloy films was measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), and the crystalline temperature of the thin films was analyzed by differential scanning calorimetry (DSC). Characterization of the crystalline structure had been performed using X-ray diffraction analysis and scanning electron microscopy. The optical properties were determined using optical spectrometer in the wavelength range from 400 to 850 nm. A higher carrier-to-noise ratio was obtained. The results indicates that Ag-In-Sb-Te based optical phase change discs could be a promising candidate for high density rewritable disc system.