Optical disk memory using amorphous rare-earth-transition-metal (RE-TM) films have been developed for erasable optical disks for applications of high density, large volume data storage. In order that the film can be used in applications, it is necessary to improve its reliability. The key factors in improving the reliability of these disks are reduction of the RE-TM film oxidation and improvement of heat-resistance property of organic substrate.
Tb-Co film forming on the epoxy-resin substrate with adequate sputtering conditions protects against oxidation and shows good magneto-optical properties. In addition, the epoxy-resin substrate has small birefringence-retardation and a smooth groove shape fabricated by means of an Omega-casting method. These results demonstrate that the optical disk with Tb-Co on epoxy substrate is suitable media for erasable disks for practical applications.
