Patent ID: 8389071

Claim:
A method of forming a carbon protective layer on a disk-shaped substrate by a plasma CVD method, the method comprising the steps of: disposing the disk-shaped substrate so that a deposition surface of the disk-shaped substrate, where the carbon protective layer is to be formed, is parallel to and spaced from an annular-shaped plasma beam generation source; and disposing a disk-shaped shield spaced from the annular plasma beam generation source between the annular-shaped plasma beam generation source and the disk-shaped substrate, wherein the disk-shaped shield is concentrically arranged with the annular-shaped plasma beam generation source and the deposition surface of the disk-shaped substrate so that a straight line connecting a center of the annular-shaped plasma beam generation source and a center of the deposition surface of the disk-shaped substrate is perpendicular to the deposition surface of the disk-shaped substrate, and, wherein the annular-shaped plasma beam generation source is composed of an annular-shaped anode having an outer diameter that is substantially the same as an outer diameter of the disk-shaped substrate, and wherein a relative position between the annular-shaped plasma beam generation source and the disk-shaped substrate is fixed.