Journal of Vacuum Science & Technology A, Vol.20, No.2, 437-440, 2002
High coercivity thin film for high-density magneto-optical super-resolution near-field recording
Magnetic and optical properties of magneto-optical TbFeCo thin films were investigated by a helicon-wave sputtering with a 200 mm distance between a substrate and target. According to deposition conditions such as power and pressure, the coercivity (H,) of the films became very high in comparison with those produced by conventional sputtering distances of 40-80 mm. It was found that the terbium (Tb) composition steeply increases with increased sputtering pressure. Decreasing the power from 150 to 50 W, Th composition further increased. A linear relationship was also discovered between the magnetic properties (H,) and optical properties (extinction coefficient, k). It is thought that high coercivity is co-related with the change of magnetic moment configuration of elements (Tb, Fe, and Co), anisotropy constant, and layer properties (the density and impurities) of the films. By controlling the sputtering pressure and power, we could obtain a magneto-optical TbFeCo thin film having a coercivity of 2.55 T and low extinction coefficient of 1.8.