| 摘要 |
<p>PURPOSE:To attain improvement in throughput and yield and miniaturization of the apparatus when wafers are delivered in different atmospheres. CONSTITUTION:A unit which is a combination of the photoemitter 8a and the photodetector 8d is arranged outside a load lock chamber 5, which incorporates mirrors 8e, 8f forming an optical path. When a semiconductor wafer W is rotated by a turn table 4d, the periphery of the wafer W passes through the optical path, and the distance from the rotation center to its periphery is detected at each rotation position. On the basis of its result, the deviation from the center from the rotation angle of the wafer W is determined; then, for example, this deviation is corrected by the transfer mechanism. Therefore, the number of handling times is saved because a separate positioning is dispensed with.</p> |
