| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To control a chamber internal pressure with high precision over a wide range while regulating a gas flow rate fed to a chamber by preventing a flow rate control precision in a low flow rate area from lowering greatly and accurately controlling the flow rate over the whole flow rate control area. <P>SOLUTION: A gas supply device formed of a plurality of pressure type flow rate controllers connected in parallel and a controller controlling operation of them supplies a desired gas to a chamber evacuated by a vacuum pump while controlling a gas flow rate. One of the pressure type flow rate controllers serves as a controller controlling a gas flow area for up to 10% of the maximum flow rate supplied to the chamber, while the rest of the pressure type flow rate controllers control the rest of the gas flow rate areas. A pressure detector is arranged in the chamber, and the detection value of the pressure detector is inputted to the controller for regulating a control signal to the pressure type flow rate controller. In this way, the gas supply quantity to the chamber is controlled, and the chamber internal pressure is controlled. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
