Temperature Dependence of Complex Refractive Index of Sputtered Sb–Te Alloy Thin Films

For the development and improvement of optical discs, the temperature dependence of the optical properties of the disc component materials is required. The temperature dependence of the complex refractive indices of Sb–Te alloy films was investigated using a spectroscopic ellipsometer in the wavelength range of 250–1700 nm and in the temperature range from room temperature to 300 °C. It was clear that the complex refractive index of Sb–Te alloys at room temperature widely change with their composition and wavelength. It was also found that the real and imaginary parts of the refractive index at a wavelength of 650 nm, which is generally used in optical discs, are decrease as the temperature increases.