Substrate processing system and process gas supply control verification method
Proposed are a substrate processing system and a process gas supply control verification method and, more particularly, to a technology to verify the operation of a mass flow controller (MFC) that supplies a process gas for semiconductor processing at an appropriate flow rate according to a recipe.
1 . A process gas supply control verification method, the method comprising:
a process gas supply step of supplying a process gas by adjusting a supply flow rate of the process gas with a mass flow controller, and supplying the process gas to a calibration tank through a bypass gas supply line;
a verification section selection step of selecting a verification time section while changing a state of the calibration tank through process gas supply;
a changing state measurement step of measuring the changing state of the calibration tank in the verification time section; and
a supply flow rate calculation step of calculating a supply flow rate of the process gas on the basis of the measurement of the changing state of the calibration tank,
wherein the process gas is a metal gas,
wherein the verification section selection step includes controlling diversion of the metal gas to the calibration tank and selecting the verification time section set in response to a supply flow rate of the metal gas in a pressure section of the calibration tank that changes linearly while the calibration tank is maintained at a controlled temperature, and
wherein in the supply flow rate calculation step, the supply flow rate is calculated using [Equation 1] below,
flow
(
sccm
)
=
α
·
273.15
(
273.15
+
C
)
·
(
V
t
+
V
p
)
760
,
TagBox[",", "NumberComma", Rule[SyntaxForm, "0"]]
000
·
(
P
2
-
P
1
T
2
-
T
1
-
Leak
)
[
Equation
1
]
wherein flow represents the supply flow rate of the process gas, α represents a correction factor, C represents temperature of the calibration tank, V t represents volume of the calibration tank, V p represents volume of the bypass gas supply line, P 1 represents pressure of the calibration tank at the start of the verification time section, P 2 represents pressure of the calibration tank at the end of the verification time section, T 1 represents start time of the verification time section, T 2 represents end time of the verification time section, and Leak represents an amount of process gas leakage from the calibration tank.
2 . The method of claim 1 ,
wherein in the verification section selection step, a verification time section of a verification pressure range is selected in a section where pressure in the calibration tank changes linearly according to the process gas supply.
3 . The method of claim 1 , wherein in the changing state measurement step, pressure and temperature of the calibration tank are measured in the verification time section.
4 . The method of claim 1 ,
wherein in the supply flow rate calculation step, the supply flow rate of the process gas supplied through the mass flow controller is calculated considering volume of the calibration tank and a volume of the bypass gas supply line on the basis of a pressure change and a temperature change in the calibration tank at start and end points of the verification time section.
5 . The method of claim 4 ,
wherein the volume of the bypass gas supply line is calculated on the basis of pressure and temperature of the process gas supplied through the bypass gas supply line.
6 . The method of claim 1 ,
wherein in the process gas supply step, the process gas is supplied to the calibration tank while a temperature of the calibration tank is controlled through a temperature control means and maintained at a set temperature.
7 . The method of claim 1 , wherein in the process gas supply step, the process gas supplied to a process gas supply line connected to a selected process chamber among a plurality of process chambers is diverted to the bypass gas supply line and supplied to the calibration tank.
8 . The method of claim 1 , wherein in the process gas supply step, the process gas supplied through a mass flow controller selected from among a plurality mass flow controllers connected to a plurality of gas source parts is diverted to the bypass gas supply line and supplied to the calibration tank.
9 . The method of claim 1 , further comprising:
a cleaning step of supplying a purge gas to the bypass gas supply line to flush the bypass gas supply line and the calibration tank.
10 . The method of claim 9 , further comprising:
a mass flow controller verification step of repeatedly performing the process gas supply step to the cleaning step to calculate an error rate for the supply flow rate and verify the mass flow controller.
11 . The method of claim 10 , further comprising:
a mass flow controller operation determination step of performing the process gas supply step and the mass flow controller verification step by changing the supply flow rate to be verified to verify the mass flow controller for each supply flow rate to be verified and determine whether the mass flow controller supplies the process gas at a verified supply flow rate corresponding to a set supply flow rate.
12 . A process gas supply control verification method, the method comprising:
a process gas supply step of supplying a metal gas by adjusting a supply flow rate of the metal gas to a supply flow rate to be verified through a mass flow controller, and supplying the metal gas to a calibration tank through a bypass gas supply line;
a verification section selection step of detecting pressure changes while increasing pressure of the calibration tank through metal gas supply, and selecting a verification time section of a verification pressure range set in response to the supply flow rate to be verified in a pressure section that changes linearly;
a flow rate calculation step of calculating a supply flow rate of the metal gas by substituting pressure measurements and a temperature measurement in the verification time section into [Equation 1] below,
flow
(
sccm
)
=
α
·
273.15
(
273.15
+
C
)
·
(
V
t
+
V
p
)
760
,
TagBox[",", "NumberComma", Rule[SyntaxForm, "0"]]
000
·
(
P
2
-
P
1
T
2
-
T
1
-
Leak
)
[
Equation
1
]
wherein flow represents a supply flow rate of a process gas, α represents a correction factor, C represents a temperature of the calibration tank, V t represents volume of the calibration tank, V p represents volume of the bypass gas supply line, P 1 represents pressure of the calibration tank at the start of the verification time section, P 2 represents pressure of the calibration tank at the end of the verification time section, T 1 represents start time of the verification time section, T 2 represents end time of the verification time section, and Leak represents an amount of process gas leakage from the calibration tank;
a cleaning step of supplying a purge gas to the bypass gas supply line to flush the bypass gas supply line and the calibration tank;
a mass flow controller verification step of repeatedly performing the process gas supply step to the cleaning step to calculate an error rate for the supply flow rate and verify the mass flow controller; and
a mass flow controller operation determination step of performing the process gas supply step and the mass flow controller verification step by changing the supply flow rate to be verified to verify the mass flow controller for each supply flow rate to be verified and determine whether the mass flow controller operates normally.