Patent ID: 8910529

Claim:
A gas flow-rate verification system for use with a process gas supply source and a process chamber, the gas flow-rate verification system comprising: a plurality of process gas lines each including a first line cutoff valve, a second line cutoff valve; a flow control device configured to supply gas from the process gas supply source to the process chamber through the first line cutoff valve, the second line cutoff valve, and the flow control device; and a shared gas line connected in a branch form to the process gas lines to discharge gas from a shared gas supply source through the second line cutoff valve and the flow control device; wherein: the shared gas line includes a shared cutoff valve, a measuring tank, a first pressure sensor, and a pressure regulating valve, in response to closing the first line cutoff valve and the shared cutoff valve, the first pressure sensor is configured to measure a pressure drop of gas in the tank to verify a flow rate of the flow control device, the pressure regulating valve is configured to feedback-control a secondary side pressure of the pressure regulating valve, the measuring tank is provided in a manifold on an upper end of which the first pressure sensor and the pressure regulating valve are placed, the manifold is formed with flow passages configured to separately communicate with an inside of the tank to respectively connect each of the first pressure sensor and the pressure regulating valve to the tank, and the volume of the tank is about 50 cc or more.