| 摘要 |
PROBLEM TO BE SOLVED: To prevent back flow of foreign matter into a process chamber during stand-by operation. SOLUTION: A process of forming a CVD film on a wafer comprises a carry-in step that carries a wafer 20 into a process chamber 4 in the atmospheric pressure, a film-forming process step in which the process chamber 4 is closed by a sealing cap 10, and a material gas is fed to the process chamber 4 from an inlet tube 9 to form the film on the wafer 20, a carry-out step in which the sealing cap 10 is opened in the atmospheric pressure to carry out the processed wafer 20 from the process chamber 4, and a stand-by step, in which the process chamber 4 is air-tight closed by a shutter 32 and is evacuated to produce reduced pressure by a vacuum pump 11 through an exhaust opening 7 and exhaust pipes 12, 14, while nitrogen gas is fed from the inlet tube 9. In the stand-by step, back flow of the foreign matter that is attached or adsorbed on the exhaust opening or on the exhaust pipes can be prevented by evacuating the process chamber to produce reduced pressure, while feeding nitrogen gas. As a result, trouble of reattaching or the like of the back-flowed foreign matters on the wafer can be prevented from occurring.
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