| 摘要 |
A method, apparatus and system for controlling a rate of pressure change in a vacuum process chamber during pump down and vent up cycles of a vacuum process are provided. The method includes sensing the pressure in the process chamber, and then controlling the rate of pressure change to achieve a desired rate for a particular vacuum process. For a pump down cycle, the apparatus can include a control valve in flow communication with the process chamber and with an evacuation pump. For a vent up cycle, the apparatus can include a control valve in flow communication with the process chamber and with an inert gas supply. With either embodiment controllers can be programmed to adjust positions of the control valves based upon feedback from pressure sensors. The system can include multiple chambers each having an associated pump down and vent up control apparatus configured to match the rates of pressure change between chambers.
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