| 摘要 |
PURPOSE: To perform an alignment operation with high accuracy without lowering a throughput by a method wherein a mask mark and a wafer mark are observed from the vertical direction with reference to the face of a mask and the alignment operation is formed. CONSTITUTION: The relative position of a mask mark and a wafer mark which are observed by a vertical detection by an image detection device 31 is detected. Then, a wafer-mask movement means 51 is driven so as to obtain a relative positional relationship as a target, and an alignment operation in an in-plane direction is performed. Then, when the alignment operation by the vertical detection is completed, a control device 50 stores the position of an image observed by an image detection device 41 in an oblique direction. Then, a semitransparent mirror 2 is pulled into the side of an objective lens tube 1 as as to be retreated from an exposure area. After its retreat, the image detection device 31 cannot observe an image by the vertical detection. Even when the image detection device 41 retreats the semitransparent mirror 2, it can observe an image by an oblique detection in the same manner as before its retreat. |
