| 摘要 |
<p>PURPOSE:To reduce the flow rate of helium required for the title device by covering the X-ray beam path from a shielding window to a mask with bellows. CONSTITUTION:When the operating state of this X-ray exposing device rises from the initial state to the exposing state, a mask cover 7 is moved so that the cover 7 can face a mask 12 by means of a driving unit 8. When the space between double bellows is pressurized, the cover 7 is expanded and airtightly fixed to a mask supporting section 5. A vacuum pump 16 evacuates the air from a stage housing chamber 6 so as to reduce the air pressure in the chamber 6 to an exposing pressure level. After the air pressure in the X-ray beam path section from a shielding window 2 in the bellows 4 to a gate valve 14 is reduced to vacuum, helium is supplied to the path section through a supply port 29 until a reduced helium pressure atmosphere for exposure is set. The helium is supplied after air is simultaneously evacuated from the spaces between the valve 14 and mask 12 and between the mask 12 and cover 7 through ports 30 and 31 by means of a pump 33 and the reduced helium pressure atmosphere for exposure is set. After the atmosphere is set, the valve 14 is opened and the cover 7 is driven to a prescribed retreated position. Therefore, the evacuating time can be reduced at the rising time of this device and the flow rate of helium can be reduced at the time of exposure.</p> |
