| 摘要 |
PURPOSE:To reduce a required space, by enabling wafers to pass through slits of two gate valves thereby every other wafer is first transferred and then the remaining wafers are transferred. CONSTITUTION:The wafers, for example twenty-five wafers, equi-spaced and stored in a cassette in a chamber A of an air-tight apparatus will be transferred into an adjacent chamber B. In this case, the two gate valves 2A, 2B each having slits 5 through which the wafers can be passed are provided between the chambers A, B, which gate valve 2A is movable, and which gate 2B is fixed. When the slits 5 of the gate valves are registered, every other wafer, that is, thirteen are transferred via slits 5 into the cassette 2B. Next, the movable gate valve 2A is moved vertically to register the slits 5, and the remaining twelve wafers are transferred into the cassette 2B. |
