METHOD OF FEEDING GAS TO EXCIMER LASER OSCILLATION DEVICE

Japanese Patent JP3818524

B2

PROBLEM TO BE SOLVED: To provide a gas feeding system for a plurality of excimer laser oscillation devices, in which the deviation in gas pressure does not exist by each line of a plurality of main lines. SOLUTION: In a method of feeding gas to a plurality of excimer laser oscillation devices, the gas feed system comprises a plurality of main lines, each having a supply end that is connected to a gas source and a tail end that is connected to an evacuation means; and a plurality of branch lines that are branched from respective main lines and are respectively connected to the excimer laser oscillation devices, where purging is carried out at all times at a flowrate of 1 cc/min or higher, at each tail end of the main lines. In a gas feeding system for feeding fluorine gas to the oscillation devices 31, a fluorinated passivation film is provided to fluorine-gas contacting surfaces. A chromium-oxide passivation film is provided on inert-gas contacting surfaces. The supply ends and the tail ends of the plurality of main lines 111a are respectively connected to common lines 111b, 111c, wherein each of the main lines has a plurality of branch lines 21, that are respectively connected to the plurality of the oscillation devices 31. Purging is carried out at all times at a flow rate of 1 cc/min or higher at the tail ends.