| 摘要 |
<p>PROBLEM TO BE SOLVED: To reduce the contacting surface of the periphery of a wafer with a cassette main body to an absolute minimum in area by a method, wherein the underside of the wafer is held only with wafer separating ribs, provided to both the side walls and inner wall pillar of a cassette. SOLUTION: A semiconductor wafer W is inserted into a cassette, passing through near the center of a groove 20 on a left side between two adjacent ribs 21. At this point, the wafer W is inserted, so as to approach inner wall pillars 13 and 32 or a frame 15 breaking away from the upper and lower wafer separating rib 21. The peripheral tip Wa of the wafer W reaches to a rib 33 breaking away from a loading/unloading device. Then, as shown by chain double-dashed line, the wafer W is held at two points on its one side with the ribs 33 and 21. That is, both the sides of the wafer W are held with the four ribs 33, 33, 21 and 21. At this point, even if the wafer W deflects slightly, it is restrained from coming into contact with a fall preventing 26.</p> |
