Calibration method and flow-rate measurement method for flow-rate controller of gas supplying apparatus

Abstract

Flow-rate calibration is executed, by opening just an exit-side opening / closing valve of a flow-rate controller to be calibrated and letting gas with a set flow-rate flow into a calibration unit (5), measuring, at time (t0) when gas temperature and gas pressure within a tank (BT) has stabilized, the gas temperature (T0) and the gas pressure (P0) within the tank (BT) for the first time, then closing an exit-side opening / closing valve (V2) of the calibration unit (5) to build up gas within the tank (BT), closing an entrance-side opening / closing valve (V1) of the calibration unit (5) at time (t1) and measuring the gas temperature (T2) and the gas pressure (P2) within the tank for the second time at time (t2), which is subsequent to the closing of the entrance-side opening / closing valve (V1), calculating the gas flow-rate (Q) from the measured values with a formula of Q = (22.4V / R DEG.t); (P2 / T2-P0 / T0) (wherein V is the internal volume of the tank (BT), R is the gas constant, and t is the build-up time (t1 - t0)), and comparing the gas flow rate that was set and the calculated as flow rate (Q).

Description

technical field [0001] The present invention relates to the improvement of the calibration method and the flow measurement method of the flow controller of the gas supply device used in the semiconductor manufacturing equipment and the pharmaceutical manufacturing equipment, etc., and relates to the flow calibration and the flow rate which can be performed quickly and with higher accuracy in a short time. Calibration method and flow measurement method of flow controller for gas supply device for measurement. Background technique [0002] A gas supply device such as a semiconductor manufacturing device generally has a structure in which a plurality of gases are switched and supplied to a gas user such as a processing chamber, and the gas whose flow rate is controlled by a flow controller provided for each type of supplied gas is supplied to the gas user. [0003] In addition, the flow rate calibration and flow measurement of the above-mentioned flow controllers are generally ...

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Problems solved by technology

[0016] The invention of the present application addresses the above-mentioned problems in the conventional flow controller calibration method and flow measurement method by the accumulation or ROR method, that is, (1) using the accumulation tank whose internal volume is known in advance based on the pressure increase rate ΔP In the method of correcting the control flow rate by / Δt and time Δt, the calculation error of the flow rate due to the fluctuation of the gas temperature during the pressure increase cannot be avoided. In addition, (2) Supply a constant flow rate to the flow path with the total internal volume V In the method of calculating the flow rate Q by calculating the difference ΔG of the mass of gas flowing into the flow path V during a certain time interval Δt, it is first necessary to obtain the volume V in the flow path by some method, and Compared with the case of using the accumulating tank BT whose internal volume is known, there is a problem that the calculation of the internal volume V of the flow path takes too much effort.

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