| 摘要 |
<p>The position of a throttle valve (4) connecting a process chamber and a vacuum line is fixed during etching process carried out on a substrate. The chamber pressure is allowed to stabilize during 'n' cycles, the pressure in the chamber is measured during etching process carried out for 'm' cycles where m>=2, the average pressure is calculated and valve position is corrected after (n+m) cycles, for setting reference pressure in the chamber. The above processes are repeated until the average pressure is equal to reference pressure.</p> |
