| 摘要 |
In accordance with the present invention, an apparatus and a method for regulating exhaust pressure in an evacuation system of a semiconductor process chamber are provided. The method comprises steps of generating a first pressure in the semiconductor process chamber with the evacuation system, monitoring the first pressure to generate a first signal, determining a set point for the exhaust pressure responsive to the first signal, and regulating the exhaust pressure by a controller till reaching the set point. The key aspect of the present invention is to maintain the equilibrium of the chamber pressure and the exhaust pressure by implementing an exhaust controller to control the gas flow rate introduced into the evacuation system. In other words, when the chamber pressure is increased, the gas is introduced into the evacuation system at an increased flow rate. On the other hand, when the chamber pressure is decreased, the gas is introduced into the evacuation system at a decreased flow rate. The dynamic control over the gas introduced into the evacuation system advantageously increase the speed of response during the changes of chamber pressure, as well as active control of the chamber pressure in place of moving the throttle valve. Thus, by minimizing the movement of throttle valve, the chances of particulate contamination of the process are greatly reduced.
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