| 摘要 |
PURPOSE:To enhance the degree of alignment accuracy by a method wherein the image of the alignment pattern of a reticle and the alignment pattern of a wafer are brought into the state wherein they are not in the relation of image formation of a reducing lens while the reticle and the image of alignment pattern of the wafer are being maintained on the same plane surface, thereby enabling to reduce the mutual interference of the reticle and the wafer alignment pattern. CONSTITUTION:When an Ar<+> laser beam which is not sensitive to resist is projected on a wafer pattern, the image of the wafer pattern is image-formed on the side located farther than the surface of reticle due to longitudinal chromatic aberration. In this case, a mirror part 27 is provided on the reticle surface, and the image 30a of the wafer pattern is formed in the vacant space aparted as far as 8 4mm from the lower part of a reticle 4 by having the laser beam reflected by the mirror part 27. The space image 29a formed by the Fresnel pattern 28 is used as the image indicating the position of the reticle. Besides, the space image 29a of the reticle and the alignment pattern 26 of the wafer are brought into the state wherein they are not related with the image of a reducing lens 3 by forming the space image 29a using an He-Ne laser beam. |
