Microstructures and Recording Mechanism of Mo/Si Bilayer Applied for Write‐Once Blue Laser Optical Recording

Mo/Si bilayer thin films were grown by magnetron sputtering and applied to write‐once blu‐ray disc (BD‐R). The microstructures and optical storage properties of Mo/Si bilayer were investigated. From the temperature dependence of reflectivity measurement, it was revealed that a phase change occurred in the range of 255–425°C. Transmission electron microscopy analysis showed that the as‐deposited film possessed Mo polycrystalline phase. The hexagonal MoSi2 and cubic Mo3Si phases appeared after annealing at 300 and 450°C, respectively. By measuring the optical reflectivity at a wavelength of 405 nm, the optical contrast of Mo/Si bilayer between as‐deposited and 450°C‐annealed states was evaluated to 25.8%. The optimum jitter value of 6.8% was obtained at 10.65 mW for 4× recording speed. The dynamic tests show that the Mo/Si bilayer has high potential in BD‐R applications.