| 摘要 |
PURPOSE:To shorten a square and reduce the effect of disturbance, to improve the reliability of positional measurement and to facilitate the alignment of a wafer by installing a rotation-angle detecting mechanism onto the shaft of a theta stage while providing a movement detecting means. CONSTITUTION:A wafer 2 coarsely adjusted so that wafer coordinates and absolute coordinates coincide is loaded and fixed onto a theta stage 1, and the initial position of the stage 1 is conformed to absolute coordinates. The quantity of displacement of wafer coordinates and absolute coordinates is measured, the stage 1 is turned and wafer coordinates and absolute coordinates are made parallel, and the angle of rotation of the stage 1 is detected by a rotation-angle detector 7. An arbitrary position on the wafer 2 is moved to an absolute- coordinate origin from the quantity of parallel displacement detected and the angle of rotation and the wafer is exposed under the state in which coordinates are mated, the stage 1 is revolved, and a movement section by revolution generated from the deviation between the rotation axis and the absolute-coordinate origin is corrected. Accordingly, the length of a square shortened and manufacturing cost is reduced while the effect of disturbance is lowered, and alignment is enabled easily. |
