| 摘要 |
PURPOSE:To measure the position of a mask efficiently and very accurately by conducting light scanning at different scanning positions and by judging the scanning condition according to a coordinate of each peak generated by the scanning light. CONSTITUTION:Light scanning is conducted at a position indicated by (i) first and then light scanning is conducted at a different position indicated by (i)+1. A peak is generated twice by each scanning light (i) and (i)+1. For example, when the scanning light is located in a region lower left of the center (p) of a mark, the first peak of the scanning light (i) and the scanning light (i)+1 is generated at nearly the same X coordinate value and the second peak of the scanning light (i) and the scanning light (i)+1 is generated at nearly the same Y coordinate value. Therefore, the scanning condition can be judged either I type or II type according to a coordinate of a peak which is generated twice by the scanning light at a certain scanning position and a coordinate of a peak which is generated twice by the scanning light at a different scanning position. |
