Method of determining flow rate of a gas in a substrate processing system

Patent metadata

Field	Value
Publication number	US-10876870-B2
Application number	US-201916238834-A
Country	US
Kind code	B2
Filing date	Jan 3, 2019
Priority date	Jan 9, 2018
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

A substrate processing system includes a gas supply unit having a first gas flow channel. A second gas flow channel of a flow rate measurement system is connected to the first gas flow channel. The flow rate measurement system further includes a third gas flow channel connected to the second gas flow channel, and a pressure sensor and a temperature sensor that measure a pressure and a temperature, respectively, in the third gas flow channel. In a method, a flow rate of a gas output from a flow rate controller of the gas supply unit is calculated using a build-up method. The flow rate of a gas is calculated without using the total volume of the first gas flow channel and the second gas flow channel and temperatures in the first gas flow channel and the second gas flow channel.

First claim

What is claimed is:

1. A method of determining a flow rate of a gas in a substrate processing system using a flow rate measurement system,
wherein the substrate processing system includes
a plurality of chamber bodies,
a plurality of gas supply units, each of which is configured to supply a gas to an internal space of a corresponding chamber body among the plurality of chamber bodies, each of the plurality of gas supply units having
a housing,
a plurality of flow rate controllers provided within the housing,
a plurality of primary valves connected to primary sides of the plurality of flow rate controllers, respectively,
a plurality of secondary valves connected to secondary sides of the plurality of flow rate controllers, respectively, and
a first gas flow channel including a plurality of first ends, a second end, and a third end, the plurality of first ends being connected to the plurality of secondary valves, respectively, the plurality of first ends, the second end, and a portion extending from the plurality of first ends to the second end being provided within the housing, and the third end being provided outside the housing and connected to the internal space of the corresponding chamber body through an on/off valve, and

a plurality of exhaust apparatuses connected to internal spaces of the plurality of chamber bodies through a plurality of exhaust flow channels, respectively, and
wherein the flow rate measurement system includes
a second gas flow channel including a plurality of fourth ends and a fifth end, each of the plurality of fourth ends being connected to the second end of a corresponding gas supply unit among the plurality of gas supply units,
a third gas flow channel having a sixth end and a seventh end,
a first valve connected between the fifth end of the second gas flow channel and the sixth end of the third gas flow channel,
a second valve connected to the seventh end of the third gas flow channel, and provided to be capable of being connected to the plurality of exhaust apparatuses,
one or more first pressure sensors configured to measure a pressure within the third gas flow channel, and
a first temperature sensor configured to measure a temperature within the third gas flow channel,
the method comprising:
evacuating the first gas flow channel, the second gas flow channel, and the third gas flow channel of one gas supply unit among the plurality of gas supply units;
acquiring a measured value P 11 of a pressure within the third gas flow channel using the one or more first pressure sensors, in a first state where a gas output from one flow rate controller among the plurality of flow rate controllers of the one gas supply unit is confined between the second valve and one secondary valve connected to a secondary side of the one flow rate controller among the plurality of secondary valves of the one gas supply unit, after said evacuating;
raising a pressure in the first gas flow channel, the second gas flow channel, and the third gas flow channel by forming a second state where a gas is supplied from the one flow rate controller to the first gas flow channel, the second gas flow channel, and the third gas flow channel, and the second valve is closed, after said acquiring a measured value P 11 ;
forming a third state where the second valve and the one secondary valve are closed, after said raising a pressure;
acquiring a measured value P 12 of a pressure within the third gas flow channel and a measured value T 12 of a temperature within the third gas flow channel in the third state, using the one or more first pressure sensors and the first temperature sensor;
forming a fourth state where the second valve is opened and the first valve is closed, from the third state;
forming a fifth state where the second valve is closed, from the fourth state;
acquiring a measured value P 13 of a pressure within the third gas flow channel in the fifth state, using the one or more first pressure sensors;
forming a sixth state where the first valve is opened from the fifth state;
acquiring a measured value P 14 of a pressure within the third gas flow channel in the sixth state, using the one or more first pressure sensors; and
determining a flow rate Q of the gas output from the one flow rate controller in the second state by executing an arithmetic operation of the following Expression (1),
Q =( P 12 −P 11 )/Δ t ×(1/ R )×( V/T )  (1)

where, in the Expression (1), Δt is a time length of an execution period of said raising a pressure, R is a gas constant, (V/T) includes {V 3 /T 12 ×(P 12 −P 13 )/(P 12 −P 14 )}, and V 3 is a default value of a volume of the third gas flow channel.

2. The method according to claim 1 ,
wherein the pressure within the third gas flow channel in the fifth state is set to be higher than the pressure within the third gas flow channel which is evacuated.

3. The method according to claim 1 ,
wherein the flow rate measurement system further includes
a fourth gas flow channel having an eighth end, a ninth end, a tenth end, a first partial flow channel extending between the eighth end and the ninth end, and a second partial flow channel branching from the first partial flow channel to extend to the tenth end, the second valve being connected between the seventh end of the third gas flow channel and the eighth end of the fourth gas flow channel,
a third valve connected between the ninth end of the fourth gas flow channel and each of the plurality of exhaust apparatuses, and
a fourth valve provided on the second partial flow channel,
the method further comprising:
connecting a tank of a reference device to the tenth end, the reference device having the tank, a second temperature sensor that measures a temperature in an internal space of the tank, a second pressure sensor that measures a pressure in the internal space of the tank, and a fifth valve connected between the fourth valve and the internal space of the tank;
acquiring a measured value P r1 of the pressure in the internal space of the tank and a measured value T r1 of the temperature in the internal space of the tank using the second pressure sensor and the second temperature sensor, respectively, in a state where a gas is confined in the internal space of the tank;
acquiring a measured value P r2 of the pressure in the internal space of the tank and a measured value T r2 of the temperature in the internal space of the tank using the second pressure sensor and the second temperature sensor, respectively, in a state where the gas confined in the internal space of the tank is diffused in the internal space of the tank and the fourth gas flow channel;
determining a calculated value V 4 of a volume of the fourth gas flow channel by executing an arithmetic operation of the following Expression (2) using an already-known volume V r of the internal space of the tank, the measured value P r1 , the measured value T r1 , the measured value P r2 , and the measured value T r2 ;
V 4 =V r ×( P r1 /T r1 −P r2 /T r2 )× T r2 /P r2   (2)

acquiring a measured value T 1f of a temperature within the third gas flow channel, a measured value P r3 of a pressure of the internal space of the tank, and a measured value T r3 of a temperature of the internal space of the tank using the first temperature sensor, the second pressure sensor, and the second temperature sensor, respectively, in a state where the gas diffused in the internal space of the tank and the fourth gas flow channel is diffused in the internal space of the tank, the third gas flow channel, and the fourth gas flow channel;
determining a calculated value V 3C of a volume of the third gas flow channel by executing an arithmetic operation of the following Expression (3) using the already-known volume V r of the internal space of the tank,

Assignees

• Tokyo Electron Ltd

Inventors

• Miyoshi Risako
• Amikura Norihiko
• Miura Kazuyuki
• Nagase Masaaki
• Yamashita Satoru
• Sawada Yohei
• Nishino Kouji
• Ikeda Nobukazu

Classifications

• G01F15/04 Primary

  of gases to be measured · CPC title

• G01F25/15

  specially adapted for gas meters (G01F25/11 - G01F25/14, G01F25/17 take precedence) · CPC title

• G05D7/0617 Primary

  specially adapted for fluid materials · CPC title

• G01F3/38

  having only one measuring chamber · CPC title

• G01F3/36 Primary

  with stationary measuring chambers having constant volume during measurement (with measuring chambers which expand or contract during measurement G01F3/02) · CPC title