| 摘要 |
PURPOSE:To improve aligning accuracy by so irradiating the outer peripheral side of a wafer with a luminous flux that an irradiating position is brought to a facet when a placed wafer is moved to the vicinity of an aligning position, and obtaining a rotation stopping position by detecting the reflected light. CONSTITUTION:A disclike wafer W having a facet F in which the outer peripheral side becomes a flat surface partly on the outer periphery is placed on a rotatably table 1 to be rotated to align the direction of the facet F to a predetermined direction. Here, the outer peripheral side of the wafer W is so irradiated with luminous flux 5 that the irradiating position is moved to the facet T when the placed wafer W is moved to the vicinity of the aligning position, and the rotation stopping position is obtained by detecting the reflected light 6. When the irradiating position is moved to the facet F by the rotation, the direction of the reflected light is moved due to flat surface upon rotation of the wafer W. Accordingly, the light 6 is detected at a predetermined position to obtain the rotation stopping position at a predetermined one point. Thus, the aligning accuracy can be improved. |
