| 摘要 |
PURPOSE:To enable to smoothly revolve a wafer and to position the wafer at the prescribed position by a method wherein the wafer is inclinably supported by three supporting points and the respective disposition of the three supporting points is designed in consideration of a smooth revolution of the wafer. CONSTITUTION:A base stand 11 is constituted in a condition inclined at a prescribed angle from the vertical direction. Supporting points 16-18 from the first to the third, by which a wafer 15 to be guided between guide rails 13 is supported, are protrudedly provided on the upper surface of the base stand 11. The wafer 15 is made to revolve by a revolution driving mechanism 21 provided on the lower side of the wafer 15. The supporting points 16 and 17 are respectively disposed on a virtual circumference S with the rotational center C of the wafer 15 as the central point thereof and across the center C on the more upper side than the center C, while the supporting point 18 is disposed on the more lower side than the center C and a position, where was intentionally avoide from a position on a virtual vertical bisector T of a line to link the supporting points 16 and 17. By disposing the supporting points 15-17 in such a way, the wafer 15 results in being supported in a moderately unstable condition, thereby enabling to smoothly revolve the wafer 15. |
