Nikon Corporation

Tatsuya Kitamoto

Shunji Watanabe

Masato Hamatani

A method for quickly removing pollutants adhered to a predetermined optical member in an optical system. To remove the pollutants adhered to a lens (A) disposed at the upper end of a projection optical system (PL), a cylindrical protecting member () is disposed through the openings in a reticle stage () and a reticle base (). The bottom surface of a support section () at the tip section of a rod section () is brought into contact with the surface of the lens (A) through the inner surface of the protecting member (). A wiping cloth soaked with a washing solution containing hydrofluoric acid is attached to the bottom surface of the support section (). The support section () is reciprocated via the rod section () to remove the pollutants on the lens (A) with the wiping cloth.

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Totsuka-ku, Japan

Tatsuya Kitamoto