| 摘要 |
PURPOSE:To reduce a discharging time and the power consumption of a vacuum pump in an excimer laser system having the gas discharging vacuum pump in its discharging system. CONSTITUTION:A bypass circuit 13 is provided to a discharge circuit 11 that connects a chamber 1 with a vacuum pump 10. In the discharge circuit 11, an on/off controllable valve (valve 1) 12 that is highly conductive is provided, while a less conductive auxiliary valve 14 is provided in the bypass circuit 13. A pressure transducer 15 is joined to an outlet opening of the chamber 1. When the gas pressure of the chamber 1 is high during the discharging operation, a vacuum pump 10 is turned on, and the auxiliary valve 14 is opened to discharge so that the power consumption of the vacuum pump 10 is reduced. Then, when the gas pressure becomes low, the main discharge valve 12 is also opened and the discharging speed is increased so that the discharge is carried out in a short time. |
