| 摘要 |
<p>PURPOSE:To detect a street position on a wafer with high precision by totalizing reflected light images over the wide region, through a slit scan by irradiating a semiconductor wafer with light while moving the wafer mounted on a table. CONSTITUTION:Horizontally-symmetric detection parts 100 and 101 detect street 3 between chips 2 on semiconductor wafer 1 and on the basis of the detection result, the Y direction and theta direction of water 1 are fixed to reference position 81 of the optical system. Next, wafer 1 is turned by 90 degrees and X-directional positioning is also attained in the same way. Namely, coarse detecting illumination 28 is used and while wafer 1 is being moved, position detection circuit 102 detects street 3 coarsely; and switching to fine-detecting illumination 29 is made and on the basis of the previously-obtained coarse-detection value and image signal 90 obtained at this time, position detection circuit 102 displays the fine position of street 3. Then, motor control circuit 103 moves table 14 correspondingly to position wafer 1.</p> |
