JPS6459652A - Optical disk - Google Patents

Abstract

PURPOSE:To cause the disk to be hardly scratched, to cause the decomposition of the reading data due to a laser light to be hard to occur and to hold a high performance for a long time by covering a surface with the hard protecting film like a diamond-shaped carbon film. CONSTITUTION:An information data pattern is formed at a substrate 11 composed of plastic, a metallic reflect mirror 12 composed of a metal such as Al is formed thereon by a vacuum-deposition, etc., on it, and further a plastic protecting film 13 is applied to the extent that a reading surface becomes flat. Thereafter, the disk manufactured like this is provided on the lower electrode in a vacuum tank. First, after the inside of the vacuum tank is lowered to a prescribed vacuum degree, CH4 and H2 are introduced. The mixing ratio with the CH4 and H2, for example, the CH4 becomes 0.1-5vol.% of the H2 and the pressure is adjusted to 0.1-10Torr. Thereafter, for example, the RF power of about 100-500W is impressed between the parallel flat plate electrodes in the vacuum tank, an RF plasma is generated, a diamond-shaped and graphite- shaped carbon film 14 is formed, the plasma is generated and vapor-deposition is executed.