In the film thickness amendment feature for the plasma CVD

摘要

PROBLEM TO BE SOLVED: To uniformly distribute the film thickness by providing a film thickness correcting plate to correct the thickness of a thin film on an equipment to form the thin film on the surface of an optical lens base material by a plasma CVD film forming method to reduce the difference in thickness of the thin films formed on the surface of a plurality of optical lens base materials. SOLUTION: A plurality of optical lens base materials whose one side is convex and whose another side is concave are horizontally arranged at the concentric position on a base plate holder 12 in a rotating condition, and the reaction gas is fed to a vacuum treatment chamber (a film farming chamber) 13 through reaction gas feed pipes 19, 29 forward of plasma sources 20, 30, and the reaction product is deposited on upper and lower sides of the lens base material. A film thickness correction mechanism comprising film thickness correcting plates 41, 42 arranged on the upper and lower side of the base plate holder 12 in the vicinity of the pipes 19, 29, is attached. The film thickness correcting plates 41, 42 function as mask members to cover the lens base material arrived in the vicinity of the pipes 19, 29 by the rotation of the base plate holder 12, and correct the film thickness to be deposited on the surface of each lens base material.