Patent Number: 053533232
Section: claims

1. An X-ray exposure apparatus comprising: X-ray generating means for generating X-rays;  a main chamber having an X-ray window for passing said X-rays and an X-ray mask attached thereto facing said X-ray window, and filled with X-ray low attenuation gas, for guiding said X-rays from said X-ray window to said X-ray mask;  gas supplying means for supplying X-ray low attenuation gas into said main chamber and having a portion with a small-diameter passage cross section formed at least at a part thereof;  gas discharging means for discharging gas from said main chamber and having a portion with a small-diameter passage cross section formed at least at a part thereof; and  flow-rate control means for controlling a flow rate of gas to be supplied to said gas supplying means to thereby control pressure in said main chamber, and  wherein a diameter of said small-diameter portion of said gas supplying means is set at a value smaller than that of said gas discharging means so that pressure in said main chamber is substantially equal atmospheric pressure.  X-ray generating means for generating X-rays;  a main chamber having an X-ray window for passing said X-rays and an X-ray mask attached thereto facing said X-ray window, and filled with X-ray low attenuation gas for guiding said X-rays from said X-ray window to said X-ray mask;  gas supplying means for supplying X-ray low attenuation gas into said main chamber and having a first portion with a small-diameter passage cross section formed at least at a part thereof: 2. The X-ray exposure apparatus according to claim 1, wherein said gas supplying means includes a pressure control chamber whose internal pressure is controllable and a restrictor provided between said pressure control chamber and said main chamber and having an orifice of a predetermined diameter, and said gas discharging means has a gas discharging passage connected to said main chamber and wider than said diameter of said orifice. 3. The X-ray exposure apparatus according to claim 2, wherein said gas supplying means has a differential pressure gauge attached to said pressure control chamber for measuring a difference between pressure in said pressure control chamber and atmospheric pressure, and flow-rate control means for controlling a flow rate of gas to be supplied to said pressure control chamber, based on a signal output from said differential pressure gauge. 4. The X-ray exposure apparatus according to claim 1, wherein said gas supplying means has a pipe coupled to said main chamber to supply said gas thereto and narrower than said small-diameter portion of said gas discharging means. 5. The X-ray exposure apparatus according to claim 1, wherein said gas discharging means has a pipe connected to said main chamber and a shield valve provided between said pipe and said main chamber for closing said pipe. 6. The X-ray exposure apparatus according to claim 1, wherein said gas discharging means has a pipe connected to said main chamber and an oxygen analyzer for measuring an amount of oxygen in said pipe. 7. The X-ray exposure apparatus according to claim 1, wherein said gas discharging means has a pipe connected to said main chamber, and an outer tube provided around said pipe, with a gas retainer formed between said pipe and said outer tube. 8. The X-ray exposure apparatus according to claim 1, wherein said gas supplying means has a gas tank and a pipe for coupling said gas tank to said gas retainer. 9. The X-ray exposure apparatus according to claim 1, wherein said gas supplying means has bypass means for supplying a large amount of gas in said main chamber at a time of activating said X-ray exposure apparatus. 10. The X-ray exposure apparatus according to claim 1, wherein said gas discharging means has a pipe connected to a vicinity of a bottom portion off said main chamber, and having a gas outlet port extending upward and then bent to be open downward. 11. An X-ray exposure apparatus comprising: 12. The X-ray exposure apparatus according to claim 11, wherein said gas supplying means includes a pressure control chamber whose internal pressure is controllable and a restrictor disposed between said pressure control chamber and said main chamber and having an orifice of a predetermined diameter, and said gas discharging means has a gas discharging passage connected to said main chamber and having a larger diameter than said diameter of said orifice.