Apparatus for the attitude control of plate-form body

摘要

An apparatus for the attitude control of a plate-form body such as mask or wafer comprises a supporting table, a first movable stage placed on the table and a second movable stage placed on the first stage. The second movable stage is provided means for holding the plate-form body on a reference plane containing the origin of the coordinates defined by two orthogonal coordinate axes. Between the supporting table and the first movable stage there is disposed first driving means. The first driving means is disposed for displacing the first movable stage at at least two positions opposed to each other relative to one of the coordinate axes. The displacement is produced in the direction substantially normal to a segment passing through the origin of the coordinates and forming a determined angle with the reference plane. The displacement of the first stage relative to the table in the direction substantially normal to the above direction is inhibited by first limiting means. Similarly second driving means is disposed between the first and second movable stages for producing the displacement of the second stage at at least two positions opposed to each other relative to the other coordinate axis. The displacement produced by second driving means is in the direction substantially normal to a segment passing through the origin of the coordinates and forming a determined angle with the reference plane. Second limiting means is provided to inhibit the displacement of the second movable stage in the direction substantially normal to the above direction of displacement by the second driving means.