EVACUATED CHAMBER AND ALIGNER USING THE SAME

摘要

PURPOSE:To control the pressure reduction atmosphere of an evacuated chamber to be high purity CONSTITUTION:The evacuated chamber 1 is controlled to be the pressure reduction atmosphere of a prescribed purity by evacuating gas in the chamber 1 by a second exhaust line 6 while helium gas is supplied from a helium gas supply line 7 after it is evacuated. The gas discharged by the line 6 is recovered by the line 7 and introduced to the chamber 1 again. The purity of the helium gas supplied by the line 7 is adjusted by purifying one part of the helium gas by the purifier 10a of a helium gas purify and branch line 10 based on the output of a purity sensor 11 detecting the purity of the discharged gas.