Hitachi, Ltd.

Yoichi Inomata

Hiroshi Matsumoto

Tokuho Takagaki

Hiroshi Yashiki

Noriyuki Shige

Tatsuya Yoneda

Kazuhiko Tsutsumi

To provide a magnetic disk excellent in floating and sliding characteristics in a low floating area. A magnetic disk having a feature that variations in the height of the projections on each surface of protective films in floating ensured areas on both sides of the magnetic disk are .+-.15%, and a magnetic disk device on which the magnetic disk is mounted. A surface processing apparatus for a magnetic disk, including: a first electrode for fixing the magnetic disk, the first electrode having an inside diameter larger than the inside diameter of the non-magnetic substrate; an electrically grounded shield for shielding the first electrode; a second electrode, disposed in parallel to the surface of the magnetic disk, for generating plasma against the surface of the magnetic disk; and a plasma control member, disposed at a position separated from the outer edge of the magnetic disk by a specified distance, for controlling plasma generated against the surface of the magnetic disk; wherein a power is applied between the first and second electrodes for plasma-etching the surface of the magnetic disk.

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Odawara, Japan

Yoichi Inomata