| 摘要 |
PURPOSE:To simply set an attitude predetermined at the flat surface by employing a light source and a plurality of photoreceptors. CONSTITUTION:A semiconductor wafer 3 is placed fixedly on a flat placing surface 2 of a flat member 1. A processor 27 receives signals from photoreceptors 25, discriminates at levels and controls stepping motors 18a, 18b, 18c. The motors 18a, 18b, 18c are driven until the all photoreceptors receive the light from the source 24, a rack 16 is lifted, and a half surface member 1 is raised. When a photoreceptor 25a, for example, receives a light from the source 24, the motor 18a is inactivated, and the rack 16a stops rising. Racks 16b, 16c are similarly operated. Thus, the upper surface of the wafer secured to the surface 2 of the member 1 can be coincident to the horizontal surface 9. |
