| 摘要 |
PURPOSE:To detect and correct positional deviation between alignment marks by a method wherein an alignment mark on a wafer and another on a mask are so patterned that their width is larger at a point farther from their centers and that the pattern on the wafer and that on the mask are so positioned that they cross each other. CONSTITUTION:Alignment marks are constituted of a pattern 11 on a wafer and a pattern 12 on a mask. Between the patterns 11 and 12, there is an overlap 13. The area of the overlap 13 registers its minimum when the center of the pattern 11 on the wafer and the center of the pattern 12 on the mask coincide. The area of the overlap 13 increases when the patterns 11 and 12 change their relative positions. The area that the overlap 13 occupies is detected by a detecting device, the pattern 12 on the mask is caused to move, for the minimization of the area the overlap 13 occupies for the correction of their positional difference. |
