| 摘要 |
PURPOSE:To form an X-ray exposure device, which hardly consumes helium gas, by shaping another groove connected to the outside air inside a groove connected to a vacuum source in a mask mounting surface. CONSTITUTION:Double annular grooves 3, 13 surrounding a hole 9 are formed to the surface 2, to which a mask 5 is fitted, in an atmospheric chamber 1, the external groove 3 is connected to a vacuum source 4 in the same manner as conventional devices, and the internal groove 13 is connected outside the atmospheric chamber by a hole 14. Consequently, the pressure of the groove 13 is made approximately the same as the outside air, a gas flowing into the groove 3 from the inside of the groove 3 through a clearance between the mounting surface 2 and the mask 5 is fed mainly from the groove 13, and helium gas in the atmospheric chamber is hardly sucked. Accordingly, the quantity of helium gas injected into the atmospheric chamber can be reduced. |
