Movable stage mechanism

Abstract

A stage device usable, e.g., in an X-ray exposure apparatus, for moving a semiconductor wafer placed in a vacuum ambience and held by a wafer chuck, is disclosed. In the stage device, the wafer chuck holds the wafer so that the surface of the wafer onto which a circuit pattern is to be transferred is placed in a vertical plane, and the wafer chuck is moved vertically and horizontally for step-and-repeat exposure of the wafer. The device includes a guide mechanism, locking mechanism and a constant-tension spring mechanism, to thereby ensure high-accuracy movement of the wafer chuck in the vertical direction as well as high-precision positioning of the wafer. Further, in the stage device, a drive source producing a drive to move the wafer chuck is disposed in a vacuum ambience while, on the other hand, the supply of operating fluids to air bearing assemblies, for guiding the movement of the wafer chuck, is achieved by use of metal pipes coupled by rotary joints. The wafer chuck is resiliently supported by one of the air bearing assemblies, such that the wafer chuck can be moved in the vacuum ambience very accurately and without difficulties.