JP6600568B2 - How to find the output flow rate of the flow controller - Google Patents

Description

  Embodiments of the present invention relate to a method for determining an output flow rate of a flow rate controller.

  A substrate processing apparatus is used in the manufacture of electronic devices such as semiconductor devices. A gas for processing a substrate is supplied from a gas supply system to a processing container of the substrate processing apparatus. The gas supply system is generally configured to supply one or more gases selected from a plurality of types of gases to the processing container of the substrate processing apparatus. Further, the gas supply system has a plurality of flow rate controllers dedicated to each of the plurality of types of gas in order to individually adjust the flow rates of the plurality of types of gas.

  As the flow rate controller, a pressure-controlled flow rate controller is known. This type of flow rate controller operates to reduce an error between a set flow rate that is a target value and a calculated flow rate that is obtained from a measured pressure value of a pressure gauge of the flow rate controller. However, the calculated flow rate of the flow rate controller becomes a flow rate having a large error with respect to the actual output flow rate of the flow rate controller as the usage time elapses. Therefore, it is necessary to obtain the output flow rate of the flow rate controller. As a technique for obtaining the output flow rate of the flow controller, a technique called a build-up technique is known. The build-up method is described in Patent Document 1.

  In the build-up method, gas is supplied into the processing container of the substrate processing apparatus via the flow rate controller to be measured, and the pressure inside the processing container, the temperature inside the processing container, and the known inside of the processing container. From the volume, the output flow rate of the flow rate controller to be measured is calculated.

Japanese Patent No. 5286430

  However, since the internal volume of the processing container is very large, the above-described conventional build-up method includes an error factor. For example, the conventional build-up method is affected by a temperature difference inside the processing container and / or a change with time of the processing container. A measure for obtaining the output flow rate of the flow rate controller by providing a flow rate measuring device in the gas supply system without using the processing vessel can be considered, but such a measure increases the cost of the gas supply system.

  Therefore, it is desired to obtain the output flow rate of the flow rate controller using existing elements in the gas supply system.

  In one aspect, a method for determining an output flow rate of a flow rate controller of a gas supply system for supplying gas into a processing container of a substrate processing apparatus is provided. The gas supply system includes a plurality of first pipes, a plurality of first valves, a plurality of flow controllers, a plurality of second pipes, a plurality of second valves, a third pipe, and a third valve. Is provided. The plurality of first pipes are pipes respectively connected to the plurality of gas sources. The plurality of first valves are provided in the plurality of first pipes. The plurality of flow controllers are pressure-controlled flow controllers and are provided downstream of the plurality of first pipes. The plurality of second pipes are provided downstream of the plurality of flow rate controllers. The plurality of second valves are provided in the plurality of second pipes. The third pipe is provided downstream of the plurality of second pipes. The third valve is provided in the third pipe. In this method, (a) in a state where the third valve is opened, the supply of the gas whose flow rate is adjusted by the flow rate controller to be measured among the plurality of flow rate controllers to the inside of the processing container is started. 1 step and (b) in a state where the supply of gas into the processing container is continued, among the plurality of flow controllers, after the measured pressure value of the pressure gauge in the flow controller for pressure measurement is stabilized, A second step of closing the third valve; and (c) a known gas supply system in which the gas supplied via the flow rate controller to be measured is stored after the third valve is closed in the second step. And a third step of calculating the output flow rate of the flow rate controller to be measured from the rate of increase of the measured pressure value of the pressure gauge in the flow rate controller for measuring pressure with respect to time.

  In the method according to one aspect, one of the plurality of existing flow controllers in the gas supply system is used as a pressure controller for pressure measurement, and the measurement is performed by the pressure controller for pressure measurement. The output flow rate of the flow rate controller is obtained from the rate of increase of the pressure value with respect to time and the known volume in the gas supply system. Therefore, according to this method, it becomes possible to obtain the output flow rate of the flow rate controller using the existing elements in the gas supply system.

  In one embodiment, the flow rate controller to be measured and the flow rate controller for pressure measurement may be one of the plurality of flow rate controllers. The one flow controller includes an orifice, a control valve upstream of the orifice, a first pressure gauge that measures the pressure in the gas line between the control valve and the orifice, and a second pressure downstream of the orifice. I have a total. In the first step of this embodiment, only the first valve upstream of the flow controller with a plurality of first valves is opened, and the second valve downstream of the flow controller with a plurality of second valves is opened. Only the valve is opened. In the second step, the third valve is closed after the measured pressure value measured by the second pressure gauge of the one flow controller is stabilized. In the third step, the rate of increase of the measured pressure value of the second pressure gauge with respect to time is used as the rate of increase of the measured pressure value of the pressure gauge in the flow controller for pressure measurement with respect to time.

  In another embodiment, the flow controller to be measured is a first flow controller of the plurality of flow controllers, and the flow controller for pressure measurement is the first flow controller of the plurality of flow controllers. It may be a second flow rate controller different from the controller. Each of the first flow controller and the second flow controller has an orifice, a control valve upstream of the orifice, and a pressure gauge that measures the pressure of the gas line between the control valve and the orifice. . In the first step of this embodiment, only the first valve upstream of the first flow controller among the plurality of first valves is opened, and the first flow controller of the plurality of second valves is opened. Only the second valve downstream of the second flow valve and the second valve downstream of the second flow controller are opened. In addition, the method of this embodiment includes (d) the second flow rate controller in a state in which the supply of gas into the processing container is continued after the execution of the first step and before the execution of the second step. A step of acquiring the measured pressure value when the measured pressure value of the pressure gauge of the first pressure gauge is stabilized as the first measured pressure value, and (e) after the execution of the second step, before the execution of the third step, and the first Closing a second valve downstream of the first flow controller when a predetermined time has elapsed from when the measured pressure value was acquired. In the second step, the third valve is closed immediately after obtaining the first measured pressure value. In the third step, as the rate of increase of the measured pressure value with respect to time, the second measured pressure value and the first measured value are the measured pressure values when the measured pressure value of the pressure gauge of the second flow rate controller is stabilized. A value obtained by dividing the difference from the pressure value by the predetermined time is used.

  In another aspect, a method for obtaining an output flow rate of a flow rate controller of a gas supply system for supplying a gas into a processing container of a substrate processing apparatus is provided. The gas supply system includes a plurality of first pipes, a plurality of first valves, a plurality of flow controllers, a plurality of second pipes, a plurality of second valves, a third pipe, and a third valve. Is provided. The plurality of first pipes are pipes respectively connected to the plurality of gas sources. The plurality of first valves are provided in the plurality of first pipes. The plurality of flow controllers are pressure-controlled flow controllers and are provided downstream of the plurality of first pipes. The plurality of second pipes are provided downstream of the plurality of flow rate controllers. The plurality of second valves are provided in the plurality of second pipes. The third pipe is provided downstream of the plurality of second pipes. The third valve is provided in the third pipe. One flow controller of the plurality of flow controllers includes an orifice, a control valve upstream of the orifice, a first pressure gauge that measures the pressure in the gas line between the control valve and the orifice, and And a second pressure gauge downstream of the orifice. The method according to this aspect includes (a) a first valve upstream of the one flow controller among the plurality of first valves, and a downstream of the one flow controller among the plurality of second valves. A first step of starting the supply of the gas whose flow rate is adjusted by the one flow rate controller into the processing container in a state where the second valve and the third valve are opened; and (b) processing. After the measured pressure value of the second pressure gauge of the one flow controller stabilizes while the gas supply into the container continues, the second valve downstream of the one flow controller is turned on. A second step of closing, and (c) a gas in which the gas supplied through the one flow rate controller is stored after the second valve downstream of the one flow rate controller is closed in the second step. The known volume of the supply system and the second pressure of the one flow controller From the rate of increase of the relative time measured pressure values, and a third step of calculating an output flow of said one flow controller, a. In the method of this aspect, a known volume upstream of the second valve downstream of one flow controller is used to determine the output flow rate of the one flow controller.

  As described above, the output flow rate of the flow rate controller can be obtained using the existing elements in the gas supply system.

It is a flowchart which shows one Embodiment of the method of calculating | requiring the output flow volume of the flow controller of the gas supply system for supplying gas in the process container of a substrate processing apparatus. It is a figure which illustrates a gas supply system. It is a figure which shows the state of the valve | bulb of the gas supply system after execution of process ST2. It is a flowchart which shows another embodiment of the method of calculating | requiring the output flow volume of the flow controller of the gas supply system for supplying gas in the process container of a substrate processing apparatus. It is a figure which shows the state of the valve | bulb of the gas supply system after execution of process ST23. It is a flowchart which shows another embodiment of the method of calculating | requiring the output flow volume of the flow controller of the gas supply system for supplying gas in the process container of a substrate processing apparatus. It is a figure which shows the state of the valve | bulb of the gas supply system after execution of process ST32.

  Hereinafter, various embodiments will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

  FIG. 1 is a flowchart illustrating an embodiment of a method for obtaining an output flow rate of a flow rate controller of a gas supply system for supplying gas into a processing container of a substrate processing apparatus. The method MT1 shown in FIG. 1 is applicable to the gas supply system shown in FIG. 2, for example.

  The gas supply system GP shown in FIG. 2 includes a plurality of first pipes L1, a plurality of first valves V1, a plurality of flow rate controllers FC, a plurality of second pipes L2, a plurality of second valves V2, 3 pipes L3 and a third valve V3.

  One ends of the plurality of first pipes L1 are connected to the plurality of gas sources GS, respectively. The plurality of gas sources GS are gas sources used for substrate processing in the substrate processing apparatus SP. The plurality of first pipes L1 are provided with a plurality of first valves V1, respectively.

  A plurality of flow rate controllers FC are provided downstream of the plurality of first pipes L1 and downstream of the plurality of first valves V1. The plurality of flow rate controllers FC are respectively connected to the other ends on the downstream side of the plurality of first pipes L1. A plurality of second pipes L2 are provided downstream of the plurality of flow rate controllers FC. One ends of these second pipes L2 are connected to a plurality of flow rate controllers FC, respectively. The plurality of second pipes L2 are provided with a plurality of second valves V2, respectively.

  A third pipe L3 is provided downstream of the plurality of second pipes L2 and downstream of the plurality of second valves V2. The other end of the plurality of second pipes L2 is connected to the third pipe L3. The third valve V3 is provided in the third pipe L3. The other end of the third pipe L3, that is, the end of the third pipe L3 downstream of the third valve V3 is connected to the processing container PC of the substrate processing apparatus SP. An exhaust device EA is provided downstream of the processing vessel PC via a pressure adjustment valve APC.

The gas supply system GP further includes a pipe LP1, a valve VP1, a pipe LP2, a valve VP2, a plurality of pipes LP4, and a plurality of valves VP4. One end of the pipe LP1 is connected to a source of purge gas such as N ₂ gas. The pipe LP1 is provided with a valve VP1. The pipe LP1 is connected to the pipe LP2 and the pipe LP3 downstream of the valve VP1. One end of the pipe LP2 is connected to the pipe LP1 downstream of the valve VP1, and the other end of the pipe LP2 is connected to the third pipe L3. A valve VP2 is provided in the pipe LP2. One end of the pipe LP3 is connected to the pipe LP1 downstream of the valve VP1. One end of a plurality of pipes LP4 is connected to the pipe LP3. The other ends of the plurality of pipes LP4 are connected to the plurality of first pipes L1 downstream of the plurality of first valves V1. These pipes LP4 are each provided with a plurality of valves VP4.

  The plurality of flow rate controllers FC are pressure control type flow rate controllers. Each of the plurality of flow rate controllers FC has a control valve CV, an orifice OF, and a pressure gauge P1. Each of the plurality of flow rate controllers FC provides a gas line GL1 upstream of the orifice OF and a gas line GL2 downstream of the orifice OF. The gas line GL1 is connected to the corresponding first pipe L1, and the gas line GL2 is connected to the corresponding second pipe L2.

  The control valve CV is provided in the gas line GL1 upstream of the orifice OF. Between the control valve CV and the orifice OF, a pressure gauge P1 that measures the pressure of the gas line GL1 is connected to the gas line GL1.

  In one embodiment, the plurality of flow rate controllers FC include a flow rate controller FC1 and a flow rate controller FC2. The flow controller FC1 further includes a pressure gauge P2. On the other hand, the flow controller FC2 among the plurality of flow controllers FC does not have the pressure gauge P2. The pressure gauge P2 is connected to the gas line GL2 in order to measure the pressure of the gas line GL2.

  The flow rate controller FC2 controls the flow rate of the gas flowing through the flow rate controller FC2 under the condition that the pressure of the gas line GL1 is twice or more the pressure of the gas line GL2. Specifically, the flow rate controller FC2 controls the control valve CV so as to reduce the difference between the calculated flow rate obtained from the measured pressure value of the pressure gauge P1 and the set flow rate. The set flow rate is set from, for example, a control unit Cnt described later.

  The flow rate controller FC1 controls the control valve CV similarly to the flow rate controller FC2 under the condition that the pressure of the gas line GL1 is twice or more the pressure of the gas line GL2. In addition, the flow rate controller FC1 is configured such that the pressure difference between the measured pressure value of the pressure gauge P1 and the measured pressure value of the pressure gauge P2 under the condition that the pressure of the gas line GL1 is smaller than twice the pressure of the gas line GL2. The control valve CV is controlled so as to reduce the difference between the calculated flow rate obtained from the above and the set flow rate.

  Further, as shown in FIG. 2, the gas supply system GP may further include a control unit Cnt. The control unit Cnt is also a control unit of the substrate processing apparatus SP, and includes, for example, a computer apparatus. The control unit Cnt controls each part of the substrate processing apparatus SP and each part of the gas supply system GP according to a recipe stored in the storage device for substrate processing in the substrate processing apparatus SP. The control unit Cnt also controls the valve of the gas supply system GP in various embodiments of the method for obtaining the output flow rate of the flow rate controller. Further, in various embodiments of the method, the control unit Cnt receives the measured pressure value of the pressure gauge P1 or the measured pressure value of the pressure gauge P2, and calculates the output flow rate of the flow rate controller.

  Hereinafter, FIG. 1 will be referred to again. As shown in FIG. 1, in the method MT1, the output flow rate of the flow rate controller FC1 is obtained using the measured pressure value of the pressure gauge P2 of the flow rate controller FC1. That is, in the method MT1, one flow rate controller FC1 is a flow rate controller to be measured, and also a flow rate controller for measuring pressure. This method MT1 starts in step ST1.

  In step ST1, supply of the gas whose flow rate is adjusted by the flow rate controller FC1 to the processing container PC is started. In this step ST1, the first valve V1 upstream of the flow controller FC1 and the second valve V2 downstream of the flow controller FC1 are opened, the other first valves V1, and the other second valves. The valve V2, the valve VP1, the valve VP2, and the plurality of valves VP4 are closed. In step ST1, the third valve V3 is opened. Thereby, the gas from the gas source GS upstream of the flow rate controller FC1 passes through the first pipe L1, the flow rate controller FC1, the second pipe L2, and the third pipe L3. To be supplied. In this step ST1, the exhaust device EA is operated and the pressure regulating valve APC is opened. The control of the gas supply system GP valve, the flow rate controller FC1, the pressure adjustment valve APC, and the like in the process ST1 may be executed by the control unit Cnt.

  In the subsequent step ST2, the measured pressure value of the pressure gauge P2 is monitored in a state where the gas supply into the processing container PC started in the step ST1 is continued. Then, after the measured pressure value of the pressure gauge P2 is stabilized, the third valve V3 is closed. For example, if the difference between the minimum value and the maximum value of the measured pressure value of the pressure gauge P2 within a predetermined time is equal to or smaller than the predetermined value, it can be determined that the measured pressure value of the pressure gauge P2 is stable. In this step ST2, the measured pressure value may be sent to the control unit Cnt, and the measured pressure value may be monitored by the control unit Cnt, and the control of the third valve V3 is executed by the control unit Cnt. May be.

  In step ST2, when the third valve V3 is closed, the state of each valve of the gas supply system GP is as shown in FIG. In FIG. 3, a black-colored figure among the figures showing the valves indicates a closed valve, and a white figure among the figures showing the valves indicates an opened valve.

  After the process ST2 is executed, the gas supplied via the flow rate controller FC1 is stored in the flow path indicated by a thick line in FIG. Specifically, the gas line GL2 of the flow controller FC1, the inside of the second pipe L2 downstream of the gas line GL2, the inside of the third pipe L3 upstream of the third valve V3, and the flow controller FC1. Gas is accumulated in the second pipe L2 downstream of the flow rate controller FC other than the second valve V2 and downstream of the second valve V2. The volume of the flow path in the gas supply system GP in which the gas is stored after the execution of the process ST2 is a volume measured in advance before the execution of the method MT1, and is a known volume Vk.

In the subsequent step ST3, the pressure increase rate (dP / dt) is obtained from the measured pressure values of the pressure gauge P2 at a plurality of time points after the execution of the step ST2. For example, the slope of a straight line that approximates the relationship between a plurality of measured pressure values and the time points at which the plurality of measured pressure values are acquired is obtained as the pressure increase rate. In step ST3, the output flow rate Q of the flow rate controller FC1 is calculated by the calculation of the following equation (1).

Q = (dP / dt) × Vk ÷ T × C (1)

In Equation (1), T is a temperature, which may be the measurement temperature of the flow path in which the gas is stored, or may be a predetermined temperature. C is a constant and has a value specified by 22.4 (liter) / R. Note that R is a gas constant.

  In step ST3, the measured pressure value of the pressure gauge P2 may be sent to the control unit Cnt, and the calculation of the pressure increase rate and the calculation of the output flow rate Q may be performed by the control unit Cnt. In addition, when all the flow controllers FC have the same structure as the flow controller FC1, the method MT1 may be sequentially executed for all the flow controllers FC.

  Hereinafter, another embodiment of the method for obtaining the output flow rate of the flow rate controller of the gas supply system for supplying gas into the processing container of the substrate processing apparatus will be described. FIG. 4 is a flowchart showing another embodiment of a method for obtaining the output flow rate of the flow rate controller of the gas supply system for supplying gas into the processing container of the substrate processing apparatus. A method MT2 shown in FIG. 4 is a method applicable to the gas supply system GP shown in FIG. In this method MT2, one flow rate controller FC is a flow rate controller to be measured, and another flow rate controller FC is a flow rate controller for pressure measurement. Each of the flow rate controller to be measured and the pressure controller for pressure measurement may have either the structure of the flow rate controller FC1 or the structure of the flow rate controller FC2. Hereinafter, the method MT2 will be described by taking as an example the case where the flow rate controller FC1 is a flow rate controller to be measured and the flow rate controller FC2 is a flow rate controller for pressure measurement.

  As shown in FIG. 4, the method MT2 starts in step ST21. In step ST21, supply of the gas whose flow rate is adjusted by the flow rate controller FC1 to the processing container PC is started. In this step ST21, the first valve V1 upstream of the flow rate controller FC1, the second valve V2 downstream of the flow rate controller FC1, and the second valve V2 downstream of the flow rate controller FC2 are opened. The first valve V1, the other second valve V2, the valve VP1, the valve VP2, and the plurality of valves VP4 are closed. In step ST21, the third valve V3 is opened. Thereby, the gas from the gas source GS upstream of the flow rate controller FC1 passes through the first pipe L1, the flow rate controller FC1, the second pipe L2, and the third pipe L3. To be supplied. In this step ST21, the exhaust device EA is operated and the pressure regulating valve APC is opened. The control of the gas supply system GP valve, the flow rate controller FC1, the pressure adjustment valve APC, and the like in the process ST21 may be executed by the control unit Cnt.

  In the subsequent step ST22, the measured pressure value of the pressure gauge P1 of the flow rate controller FC2 is monitored while the supply of gas into the processing container PC started in step ST21 is continued. Then, the measured pressure value when the measured pressure value of the pressure gauge P1 of the flow rate controller FC2 is stabilized is acquired as the measured pressure value Pm1. In step ST22, the measurement pressure value of the pressure gauge P1 of the flow rate controller FC2 may be sent to the control unit Cnt, and monitoring of the measurement pressure value and acquisition of the measurement pressure value Pm1 may be executed by the control unit Cnt. .

  In the subsequent step ST23, the third valve V3 is closed immediately after obtaining the measured pressure value Pm1 in the step ST22. Control of the 3rd valve V3 in this process ST23 may be performed by control part Cnt.

  When the third valve V3 is closed in step ST23, the state of each valve of the gas supply system GP is as shown in FIG. In FIG. 5, a black-colored figure among the figures showing the valves indicates a closed valve, and a white figure among the figures showing the valves indicates an open valve. In the state shown in FIG. 5, the control valve CV of the flow rate controller FC2 is opened.

  After the execution of step ST23, the gas supplied via the flow rate controller FC1 is stored in the flow path indicated by a thick line in FIG. Specifically, the gas line GL2 of the flow rate controller FC1, the inside of the second pipe L2 downstream of the gas line GL2, the inside of the third pipe L3 upstream of the third valve V3, the upstream of the flow rate controller FC2 In addition, the inside of the first pipe L1 downstream of the corresponding first valve V1, the inside of the pipe LP4 upstream of the flow rate controller FC2 and the downstream of the corresponding valve VP4, the gas line GL1 and the gas line GL2 of the flow rate controller FC2 , The second pipe L2 downstream of the flow rate controller FC2, and the second pipe downstream of the second valve V2 and downstream of the flow rate controller FC other than the flow rate controller FC1 and the flow rate controller FC2. Gas is stored inside L2. Thus, the volume of the flow path in the gas supply system GP in which the gas is stored after the execution of the process ST23 is a volume measured in advance before the execution of the method MT2, and is a known volume Vk2.

  In the state shown in FIG. 5, the control valve CV of the flow rate controller FC2 is opened, but the control valve CV of the flow rate controller FC2 may be closed. When the control valve CV of the flow controller FC2 is closed, the known volume Vk2 is a first valve upstream of the flow controller FC2 and corresponding to the volume of the flow path indicated by a thick line in FIG. The volume is small by the amount inside the first pipe L1 downstream of V1 and inside the pipe LP4 upstream of the flow rate controller FC2 and downstream of the corresponding valve VP4.

  In the subsequent step ST24, the second valve V2 downstream of the flow rate controller FC1 is closed after the execution of the step ST23 and when a predetermined time has elapsed since the acquisition of the measured pressure value Pm1. The control of the second valve V2 in this step ST23 may be executed by the control unit Cnt.

  In the subsequent step ST25, the measured pressure value of the pressure gauge P1 of the flow rate controller FC2 is monitored. Then, the measured pressure value when the measured pressure value of the pressure gauge P1 of the flow rate controller FC2 is stabilized is acquired as the measured pressure value Pm2. In addition, if the difference between the minimum value and the maximum value within a predetermined time of the pressure value measured by the pressure gauge P1 of the flow controller FC2 is equal to or less than the predetermined value, the measured pressure value of the pressure gauge P1 of the flow controller FC2 is stable. Can be determined. Thereafter, in step ST25, a pressure increase rate (dP / dt) is obtained. The rate of pressure increase is determined by the calculation of (Pm2-Pm1) / Δt. Note that Δt is the time difference between the time when the measured pressure value Pm1 is acquired and the time when the second valve V2 is closed in step ST24.

In step ST25, the output flow rate Q of the flow rate controller FC1 is then calculated by the calculation of the following equation (2).

Q = (dP / dt) × Vk2 ÷ T × C (2)

In Equation (2), T is a temperature, which may be the measurement temperature of the flow path in which the gas is stored, or may be a predetermined temperature. C is a constant and has a value specified by 22.4 (liter) / R. Note that R is a gas constant.

  In step ST25, the measurement pressure value of the pressure gauge P1 of the flow rate controller FC2 is sent to the control unit Cnt, and the control unit Cnt monitors the measurement pressure value, calculates the pressure increase rate, and calculates the output flow rate Q. It may be done. Further, the method MT2 may be executed for all the flow rate controllers FC in order.

  Hereinafter, still another embodiment of the method for obtaining the output flow rate of the flow rate controller of the gas supply system for supplying gas into the processing container of the substrate processing apparatus will be described. FIG. 6 is a flowchart showing still another embodiment of a method for obtaining an output flow rate of a flow rate controller of a gas supply system for supplying gas into a processing container of a substrate processing apparatus. A method MT3 shown in FIG. 6 is a method applicable to the gas supply system GP shown in FIG. This method MT3 is a modification of the method MT1.

  Method MT3 starts in step ST31. Step ST31 is the same as step ST1. In method MT3, step ST32 is then performed. In step ST32, the measured pressure value of the pressure gauge P2 of the flow rate controller FC1 is monitored while the supply of gas into the processing container PC started in step ST31 is continued. Then, after the measured pressure value of the pressure gauge P2 is stabilized, the second valve V2 downstream of the flow rate controller FC1 is closed. For example, if the difference between the minimum value and the maximum value of the measured pressure value of the pressure gauge P2 within a predetermined time is equal to or smaller than the predetermined value, it can be determined that the measured pressure value of the pressure gauge P2 is stable. In this step ST32, the measurement pressure value may be sent to the control unit Cnt, and the measurement pressure value may be monitored by the control unit Cnt, and the second valve V2 downstream of the flow rate controller FC1 is controlled. May be executed by the control unit Cnt.

  In step ST32, when the second valve V2 downstream of the flow rate controller FC1 is closed, the state of each valve of the gas supply system GP is as shown in FIG. In FIG. 7, a black-colored figure among the figures showing the valves indicates a closed valve, and a white figure among the figures showing the valves indicates an opened valve.

  After the execution of step ST32, the gas supplied via the flow rate controller FC1 is stored in the flow path indicated by a thick line in FIG. Specifically, gas is stored in the upstream portion of the second valve V2 in the gas line GL2 of the flow rate controller FC1 and the second pipe L2 downstream of the gas line GL2. The volume of the flow path in the gas supply system GP in which gas is stored after the execution of the process ST32 is a volume measured in advance before the execution of the method MT3, and is a known volume Vk3.

In the subsequent step ST33, the pressure increase rate (dP / dt) is obtained from the measured pressure values of the pressure gauge P2 at a plurality of time points after the execution of the step ST32. For example, the slope of a straight line that approximates the relationship between a plurality of measured pressure values and the time points at which the plurality of measured pressure values are acquired is obtained as the pressure increase rate. In step ST33, the output flow rate Q of the flow rate controller FC1 is calculated by the calculation of the following equation (3).

Q = (dP / dt) × Vk3 ÷ T × C (3)

In Equation (3), T is a temperature, and may be the measurement temperature of the flow path in which the gas is stored, or may be a predetermined temperature. C is a constant.

  In step ST33, the measured pressure value of the pressure gauge P2 may be sent to the control unit Cnt, and the calculation of the pressure increase rate and the calculation of the output flow rate Q may be performed by the control unit Cnt. Further, when all the flow controllers FC have the same structure as that of the flow controller FC1, the method MT3 may be sequentially executed for all the flow controllers FC.

  In any of the above-described embodiments, the output flow rate of the flow controller of the gas supply system can be obtained using the measured pressure value of the pressure gauge of the existing pressure control type flow controller of the gas supply system. Is possible. Moreover, the above-mentioned known volume is the volume of the existing flow path in the gas supply system GP, and the volume is smaller than the volume inside the processing container PC. Moreover, the temperature difference of the flow path is smaller than the temperature difference in the processing container PC, and the temperature of the flow path is stable. Therefore, in any of the above-described embodiments, the output flow rate of the flow rate controller can be obtained with high accuracy.

  GP ... gas supply system, GS ... gas source, L1 ... first pipe, L2 ... second pipe, L3 ... third pipe, V1 ... first valve, V2 ... second valve, V3 ... third Valve, FC, FC1, FC2 ... flow rate controller, CV ... control valve, OF ... orifice, P1 ... pressure gauge, P2 ... pressure gauge, SP ... substrate processing apparatus, PC ... processing vessel, APC ... pressure regulating valve, EA ... exhaust device, Cnt ... control section.

Claims (4)

A method for obtaining an output flow rate of a flow rate controller of a gas supply system for supplying gas into a processing container of a substrate processing apparatus,
The gas supply system
A plurality of first pipes respectively connected to a plurality of gas sources;
A plurality of first valves provided in the plurality of first pipes;
A plurality of pressure-controlled flow rate controllers provided downstream of the plurality of first pipes;
A plurality of second pipes provided downstream of the plurality of flow rate controllers;
A plurality of second valves provided in the plurality of second pipes;
Third and pipe connected to the processing chamber of said plurality of second said substrate processing apparatus is provided, et al is in the downstream of the pipe,
A third valve provided in the third pipe;
With
The method
A first step of starting supply of the gas whose flow rate is adjusted by the flow rate controller to be measured among the plurality of flow rate controllers in the state where the third valve is opened;
After the measurement pressure value of the pressure gauge in the flow rate controller for pressure measurement among the plurality of flow rate controllers is stabilized while the supply of the gas into the processing container is continued, the third valve A second step of closing
In the second step, after the third valve is closed, the known volume of the gas supply system in which the gas supplied via the flow rate controller to be measured is stored, and the flow rate for pressure measurement A third step of calculating the output flow rate of the flow rate controller to be measured from the rate of increase of the measured pressure value of the pressure gauge in the controller with respect to time;
Including methods. The flow controller for measurement and the flow controller for pressure measurement are one of the plurality of flow controllers,
The one flow controller is an orifice, a control valve upstream of the orifice, a first pressure gauge that measures the pressure of the gas line between the control valve and the orifice, and downstream of the orifice Having a second pressure gauge,
In the first step, only the first valve upstream of the one flow controller among the plurality of first valves is opened, and the one flow controller of the plurality of second valves is opened. Only the downstream second valve is formed,
In the second step, after the measured pressure value measured by the second pressure gauge of the one flow controller is stabilized, the third valve is closed,
In the third step, the rate of increase of the measured pressure value of the second pressure gauge with respect to time is used as the rate of increase of the measured pressure value of the pressure gauge in the flow controller for pressure measurement with respect to time.
The method of claim 1. The flow rate controller to be measured is a first flow rate controller among the plurality of flow rate controllers,
The flow rate controller for measuring pressure is a second flow rate controller different from the first flow rate controller among the plurality of flow rate controllers,
Each of the first flow controller and the second flow controller includes an orifice, a control valve upstream of the orifice, and a pressure that measures the pressure of the gas line between the control valve and the orifice. Have a total
In the first step, only the first valve upstream of the first flow rate controller among the plurality of first valves is opened, and the first flow rate control among the plurality of second valves is opened. Only the second valve downstream of the vessel and the second valve downstream of the second flow controller are opened,
The method
After the execution of the first step and before the execution of the second step, the measured pressure of the pressure gauge of the second flow rate controller in a state where the supply of the gas into the processing container is continued. Obtaining the measured pressure value when the value is stabilized as a first measured pressure value;
After the execution of the second step, before the execution of the third step, and when a predetermined time has elapsed from the time when the first measured pressure value is acquired, the second step is downstream of the first flow controller. Closing the second valve;
Further including
In the second step, the third valve is closed immediately after obtaining the first measured pressure value,
In the third step, as a rate of increase of the measured pressure value with respect to time, a second measured pressure value that is the measured pressure value when the measured pressure value of the pressure gauge of the second flow rate controller is stabilized; A value obtained by dividing the difference from the first measured pressure value by the predetermined time is used.
The method of claim 1. A method for obtaining an output flow rate of a flow rate controller of a gas supply system for supplying gas into a processing container of a substrate processing apparatus,
The gas supply system
A plurality of first pipes respectively connected to a plurality of gas sources;
A plurality of first valves provided in the plurality of first pipes;
A plurality of pressure-controlled flow rate controllers provided downstream of the plurality of first pipes;
A plurality of second pipes provided downstream of the plurality of flow rate controllers;
A plurality of second valves provided in the plurality of second pipes;
Third and pipe connected to the processing chamber of said plurality of second said substrate processing apparatus is provided, et al is in the downstream of the pipe,
A third valve provided in the third pipe;
With
One flow controller of the plurality of flow controllers includes an orifice, a control valve upstream of the orifice, a first pressure gauge that measures a pressure of a gas line between the control valve and the orifice, And a second pressure gauge downstream of the orifice,
The method
A first valve upstream of the one flow controller of the plurality of first valves, a second valve downstream of the one flow controller of the plurality of second valves, and A first step of starting the supply of the gas whose flow rate is adjusted by the one flow rate controller into the processing vessel in a state where the third valve is opened;
After the measured pressure value of the second pressure gauge of the one flow controller is stabilized in a state where the supply of the gas into the processing container is continued, the downstream of the one flow controller A second step of closing the second valve;
The known volume of the gas supply system in which the gas supplied through the one flow controller is stored after the second valve downstream of the one flow controller is closed in the second step. And a third step of calculating the output flow rate of the one flow controller from the rate of increase of the measured pressure value of the second pressure gauge of the one flow controller with respect to time,
Including methods.

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