RF sputtering apparatus and sputtering method

A RF sputtering apparatus for performing film forming processing on one surface of a substrate by applying RF power to a target in vacuum, the sputtering apparatus comprising:

• a stage for holding the substrate in a state of leaving said one surface open and of being electrically insulated, wherein the stage has a dented portion on such a holding surface as is adapted to hold thereon the substrate;
• and
• a movable body disposed in a space defined by such an opposite surface of the substrate as is opposite to said one surface and an outline of the dented portion when the substrate is held such that a peripheral edge portion thereof is held so as to come into contact with the holding surface of the stage, the movable body being movable toward, and away from, the substrate, and being connected to grounding, and
• wherein the movable body comprises a first movable portion having a confronting surface of a predetermined area confronting a central region of the substrate, and
• a diameter of the first movable portion is smaller than a diameter of the substrate so as to locally vary self-bias potential, control an amount of reverse sputtering, and adjust an in-plane film thickness distribution on the substrate.