| 摘要 |
PURPOSE:To prevent adverse effects such as deformation and strain of resist and the like, which are applied on a wafer, separation of the resist and the like, by detecting the position and the orientation flat of the wafer by an area image sensor, moving a stage, to which the wafer is sucked, and performing prealignment. CONSTITUTION:Image sensors IS-1-IS-6 are attached to a fixed stage ST-1 for detecting the position, the center and the orientation flat of the wafer 2 so as to correspond to two-dimensional scanning light generators LS-1, LS-2.... A moving stage ST-2 in a prealignment part 4 can be moved in the three directions of X, Y and Z, which are crossed at right angles. The stage can be rotated around an axis theta, which is orthogonal to the X-Y plane. By moving the stage ST-2, the prealignment of the wafer 2 is performed. The wafer 2 can be sucked and levitated with air blowing on the stage ST-2.
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