| 摘要 |
<p>A method for sensing a location of an alignment mark is provided to prevent a defect of an alignment process by averaging center points of a normal image and a reflected image of the alignment mark. An alignment mark is formed on a wafer. The wafer having the alignment mark is fitted in an aligner(S110). An image of the alignment mark is enlarged using an optical unit and picked up the image using a photographer(S130). The image of the alignment mark is verified whether having a left and right symmetrical structure or up and down symmetrical structure(S140). If the image of the alignment mark has not both of the symmetrical structure, the image of the align mark is reflected(S160). A center point is decided by averaging a center point of the reflected image of the alignment mark and a normal center point of the image of the alignment mark(S170).</p> |
