| 摘要 |
PROBLEM TO BE SOLVED: To provide a projection aligner for suppressing the risk of defocusing a pattern image by trimming while excluding the influence of the surface state of a substrate. SOLUTION: The step on a wafer W is detected in advance, and an approximation surface APF that is approximated to the surface of the wafer W is obtained. While detection points AFij ' and AFij" that are located at positions being greatly collapsed or projecting from the approximation plane APF are eliminated, a plurality of detection points AFij near the approximation surface APF are selected, the position in the direction of the light axis of the surface of the wafer W is detected based on the position information, and the approximation plane APF of the wafer W is trimmed to the image surface of a projection optical system based on the detection result. |
