| 摘要 |
PROBLEM TO BE SOLVED: To obtain a magnetically levitated transfer apparatus for single-wafer storage cassettes, which protects wafers against contamination from their surrounding environment in a transfer passage, uses less amounts of chemical-free dry air required for pollution control, and implements a space saving clean room. SOLUTION: This apparatus comprises an in-process transfer passage 18 and stockers 20 for the groups of processing units 1. The passage 18, which is of a magnetically levitated type and has a closed box-shaped body, allows cassettes 24 to be transferred to the unit 1, each cassette 24 storing wafers to be processed vertically for single-wafer processing. The stockers 20 are placed on top of another in a utility zone 21. Chemical-free dry air generated by a chemical air generator 33, a dry coil 35 and a filter 37 is supplied by means of a circulating fan 36 to a wafer transfer passage including the passage 18 and the stockers 20, so as to keep the pressure within the transportation passage in positive state. |
