| 摘要 |
<p>PURPOSE: To realize alignment excellent in alignment precision which is hard to be affected by noise, by superposing a first peripheral form signal showing the position coordinate of an outer peripheral form of a rotation of a body to be processed, after shifting one-half period. CONSTITUTION: The outer peripheral form of a wafer W which is optically detected by a detecting means 34 is sent to a first operating means 62, as a first peripheral form signal 60. The first operating means 62 obtains a second peripheral form signal 64, by superposing the first peripheral form signal 60 of a rotation of the wafer W mounted on a rotary mounting stand, after shifting one-half period. In the second peripheral form signal 64, curve parts shifted by one-half period are mutually canceled, and only the peak part 66 corresponding to a notch mark part which has transmitted a light is remarkably shown.</p> |
