Gas inspection method, substrate processing method, and substrate processing system

1. A gas inspection method of inspecting a gas supply configured to supply a gas into a chamber, wherein the gas supply includes a pipe configured to connect a gas source and the chamber to each other, a flow rate controller provided in the pipe, a primary valve provided on an upstream side of the flow rate controller, and a secondary valve provided on a downstream side of the flow rate controller, and wherein the flow rate controller includes an orifice, a primary pressure gauge provided on an upstream side of the orifice, and a secondary pressure gauge provided on a downstream side of the orifice, the method comprising:

(a) setting, in the flow rate controller, a threshold value P 0 of a pressure on the downstream side of the orifice of the flow rate controller at a time point when a period t elapses from an input of a signal for opening the secondary valve, and a threshold value σ 0 of a standard deviation of the pressure;

(b) inputting the signal for opening the secondary valve;

(c) measuring, by the secondary pressure gauge, a pressure P on the downstream side of the orifice of the flow rate controller at the time point when the period t elapses from the input of the signal for opening the secondary valve;

(d) measuring, by the secondary pressure gauge, a standard deviation σ of the pressure P on the downstream side of the orifice of the flow rate controller at the time point when the period t elapses from the input of the signal for opening the secondary valve; and

(e) determining whether or not an open degree of the secondary valve is normal by comparing the pressure P measured in (c) and the standard deviation σ of the pressure P measured in (d) with the threshold value P 0 of the pressure and the threshold value σ 0 of the standard deviation of the pressure, which are set in (a), respectively.

2. The gas inspection method of claim 1 , wherein the threshold value P 0 of the pressure, which is set in (a), on the downstream side of the orifice of the flow rate controller at the time point when the period t elapses after the input of the signal for opening the secondary valve is 10 kPa to 30 kPa, and the threshold value σ 0 of the standard deviation of the pressure is 1 kPa to 5 kPa.

3. The gas inspection method of claim 1 , wherein the period tin (a), (b), and (c) is five seconds to ten seconds.

4. The gas inspection method of claim 1 , wherein (a) includes setting the threshold value P 0 of the pressure and the threshold value σ 0 of the standard deviation of the pressure from the pressure P measured by the secondary pressure gauge when the secondary valve is normally opened and a standard deviation of the pressure P measured by the secondary pressure gauge when the secondary valve is normally opened, respectively.

5. The gas inspection method of claim 1 , further comprising:

(i) when the pressure P measured in (c) is determined in (e) to be equal to or less than the threshold value P 0 of the pressure set in (a) and the standard deviation σ of the pressure P measured in (d) is determined in (e) to be equal to or less than the threshold value σ 0 of the standard deviation of the pressure set in (a), determining that an operation of opening the secondary valve is normal and continuing processing a substrate.

6. A substrate processing method, comprising:

the method of inspecting the gas supply according to claim 1 ,

wherein a substrate is processed using the gas supplied from the gas supply.

7. The gas inspection method of claim 1 , wherein (a) includes:

(f) measuring, a plurality of times by the secondary pressure gauge, the pressure P when the secondary valve is in a normally opened state under specific processing conditions and a standard deviation of the pressure P when the secondary valve is in the normally opened state under the specific processing conditions; and

(g) setting the threshold value P 0 of the pressure and the threshold value σ 0 of the standard deviation of the pressure based on the pressures and standard deviations measured in (f), respectively.

8. The gas inspection method of claim 7 , wherein (g) includes setting the threshold value P 0 of the pressure and the threshold value σ 0 of the standard deviation of the pressure to be values obtained by multiplying a maximum value among the pressures measured in (f) by a first coefficient and multiplying a maximum value among the standard deviations measured in (f) by a second coefficient, respectively.

9. The gas inspection method of claim 8 , wherein each of the first coefficient and the second coefficient falls within a range of 1 to 8.

10. A system for processing a substrate using a gas, the system comprising:

a chamber including a gas supply port and a gas exhaust port;

a gas supply configured to supply the gas to the chamber; and

a controller,

wherein the gas supply includes a pipe configured to connect a gas source and the chamber to each other, a flow rate controller provided in the pipe, a primary valve provided on an upstream side of the flow rate controller, and a secondary valve provided on a downstream side of the flow rate controller,

wherein the flow rate controller includes an orifice, a primary pressure gauge provided on an upstream side of the orifice, and a secondary pressure gauge provided on a downstream side of the orifice, and

wherein the controller is configured to control the system to execute a processing including processes of:

(a) setting, in the flow rate controller, a threshold value P 0 of a pressure on the downstream side of the orifice of the flow rate controller at a time point when a period t elapses from an input of a signal for opening the secondary valve, and a threshold value σ 0 of a standard deviation of the pressure;

(b) inputting the signal for opening the secondary valve;

(c) measuring, by the secondary pressure gauge a pressure P on the downstream side of the orifice of the flow rate controller at the time point when the period t elapses from the input of the signal for opening the secondary valve;

(d) measuring, by the secondary pressure gauge a standard deviation σ of the pressure P on the downstream side of the orifice of the flow rate controller at the time point when the period t elapses from the input of the signal for opening the secondary valve; and

(e) determining whether or not an open degree of the secondary valve is normal by comparing the pressure P measured in (c) and the standard deviation σ of the pressure P measured in (d) with the threshold value P 0 of the pressure and the threshold value σ 0 of the standard deviation of the pressure, which are set in (a).