| 摘要 |
PROBLEM TO BE SOLVED: To provide a film forming vacuum valve having simple and effective construction, capable of preventing the deposition of by-products on a valve seat and a valve seal member. SOLUTION: At a position on the inner periphery side of a valve opening/closing portion 19 of the vacuum valve formed between the valve seat 16 and the valve seal member 18, an annular wall 41 and an annular groove 42 are arranged which are mutually fitted at the initial stage of opening the valve seat 16 to form a micro throttle flow path 43. Reactive gas distributes through the throttle flow path 43 at a high speed before distributing through the valve opening/closing portion 19, whereby by-products are deposited on the annular wall 41 and the annular groove 42. COPYRIGHT: (C)2008,JPO&INPIT
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