Patent ID: 7594517
Filing Date: 2009-09-29
Classification: G05D,Y10T

Abstract:
1. A gas supply facility for a chamber, wherein the gas supply facility comprises: (a) a chamber exhausted by a vacuum pump; (b) a first pressure type flow controller controlling a small flow rate corresponding to 10% of a maximum flow rate of the gas supply facility to the chamber; (b) a second pressure type flow controller controlling a large flow rate corresponding to 90% of the maximum flow rate of the gas supply facility to the chamber, wherein the second pressure type flow controller is connected in parallel with the first pressure type flow controller; (c) a third controller operably connected to control operation of the first pressure type flow controller and the second pressure type flow controller; wherein the first pressure type flow controller and the second pressure type flow controller each comprises wherein the third controller comprises wherein the first pressure type flow controller is initially operated to control small flow rate and when flow rate reaches 10% of the maximum flow rate the second pressure type flow controller is switched into operation, wherein first control signals for both the first pressure type flow controller and the second pressure type flow controller are provided by the signal conversion part thereby enabling accurate flow rate control over a wide flow rate range by remitting first control signals from the signal conversion part to the first pressure type flow controller and the second pressure type flow controller.