Device for positioning circular semiconductor wafers

摘要

A device for positioning a circular substrate having a cut portion, comprising: a first rotational stage which is finely rotated around the origin of a rectangular coordinate system; an X-Y stage on the first rotational stage which is two-dimensionally moved in the coordinate system; a second rotational stage on the X-Y stage which is rotated while holding the substrate; a first detecting device for detecting information about the displacement change of the periphery of the substrate from the rotational center during the rotation of the second rotational stage; a first positioning controlling device for controlling the rotation of the second rotational stage in accordance with information detected by the first detecting device so that the cut portion is placed in a predetermined direction on the coordinate system; a second detecting device having three or more detecting points in the coordinate system so as to detect the three or more positions of the periphery, the second detecting device generating information about a detection at each of the three or more detecting points; and a second positioning controlling device for controlling the X-Y stage and the first rotational stage in accordance with the detection information from the second detecting device after the cut portion has been placed in the predetermined direction.