Patent ID: 7273534

Claim:
An optical disk substrate film-formation apparatus which manufactures an optical disk by forming a thin film on the surface of a substrate, said apparatus comprising: a substrate holder which fixes said substrate during the formation of said film, wherein said substrate holder includes, a contact holding surface contacting at least a portion of a rear surface of a film-formed area of said substrate on which said film is formed, a vacuum chuck section for adsorbing and fixing said contact holding surface to said substrate, and a removal claw having an inclined section configured to go into a section between a rear surface of the substrate and a top surface of the substrate holder to mechanically peel off the adsorbed substrate from the substrate holder, wherein said apparatus is configured to perform sputter film formation in which a laminated film is formed by combining any one or two or more of a reflection layer, a recording layer, a protection layer, or a dielectric body layer on the disk substrate, wherein at least one groove section extending once around a center of a section where the disk is placed and having a construction in which an angle between a tangent to a rim of said at least one groove at any position and a tangent to a circle around a center of a section where said disk substrate is placed at the same position is not more than 30 degrees and is provided in an area of a surface of a substrate holder opposing to a film-formed area of the disk substrate, and a portion other than said groove section contacts and supports the rear surface of the film-formed area of said disk substrate.