Substrate treating system and substrate treating method

Abstract

To appropriately measure a flow rate of a gas output from a flow rate controller in a substrate treating system.SOLUTION: A substrate treating system includes multiple chambers, multiple gas boxes, a flow rate measuring device, an exhaust unit, and a control section for executing a substrate treating method. The exhaust unit includes multiple first exhaust pipes and a second exhaust pipe. Each of the multiple chambers includes an exhaust mechanism. The flow rate measuring device includes a flow rate measurement unit. The substrate treating method stops the circulation of a treatment gas between the flow rate measuring device and the second exhaust pipe and evacuates the flow rate measuring device by the one exhaust mechanism (a), supplies the treatment gas to the flow rate measuring device, circulates the treatment gas between the flow rate measuring device and the second exhaust pipe in a state in which at least the pressure in the flow rate measurement unit is higher than the pressure in the second exhaust pipe (b), and measures the flow rate of the treatment gas (c).SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing system and a substrate processing method. [Background technology]

[0002] Patent Document 1 discloses a method for calculating the flow rate of gas output from a flow controller to a gas flow path using a build-up technique based on the rate of increase in pressure in the gas flow path due to gas supply, the temperature in the gas flow path, and a known gas flow path volume. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-120617 A Summary of the Invention [Problem to be solved by the invention]

[0004] The technology disclosed herein appropriately measures the flow rate of a gas output from a flow rate controller in a substrate processing system. [Means for solving the problem]

[0005] One aspect of the present disclosure is a substrate processing system including a plurality of chambers for processing a substrate in a desired process gas, a plurality of gas boxes for supplying the process gas to each of the plurality of chambers, a flow rate measuring device for measuring a flow rate of the process gas supplied from the plurality of gas boxes, an exhaust unit connected to the plurality of chambers and the flow rate measuring device, and a control unit configured to be able to execute a substrate processing method, the system including a plurality of first exhaust pipes connected to each of the plurality of chambers, and a second exhaust pipe connected to the flow rate measuring device and the first exhaust pipe, and each of the plurality of chambers includes an exhaust mechanism for exhausting the process gas to a corresponding one of the first exhaust pipes. The flow measurement device includes a flow measurement unit, and the substrate processing method includes the steps of: (a) stopping the flow of the process gas between the flow measurement device and the second exhaust piping, and creating a first state in which the flow measurement device is evacuated by one of the exhaust mechanisms connected to one of the chambers; (b) after the step (a), supplying the process gas to the flow measurement device from one of the gas boxes corresponding to one of the chambers, and creating a second state in which at least the pressure inside the flow measurement unit is higher than the pressure inside the second exhaust piping, and allowing the process gas to flow between the flow measurement device and the second exhaust piping in the second state; and (c) measuring a flow rate of the process gas. Effect of the Invention

[0006] According to the present disclosure, the flow rate of a gas output from a flow rate controller in a substrate processing system can be appropriately measured. [Brief description of the drawings]

[0007] [Figure 1] 1 is a plan view showing a configuration example of a wafer processing system according to an embodiment; [Diagram 2] FIG. 2 is a system diagram showing a configuration example of a gas supply mechanism according to an embodiment. [Diagram 3] FIG. 2 is a partial diagram of a system diagram showing a configuration example of a gas supply mechanism according to an embodiment. [Figure 4] FIG. 4 is a flow chart showing a method for measuring a gas flow rate according to an embodiment. [Diagram 5] 5 is an explanatory diagram showing the opening and closing timing of a valve in the gas flow rate measuring method shown in FIG. 4. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] In the manufacturing process of semiconductor devices, various gas processes such as etching, film formation, cleaning, etc. are performed under a desired gas atmosphere on a semiconductor substrate (hereinafter referred to as "wafer") placed in the internal space of a chamber. In these gas processes, it is important to precisely measure the flow rate of the gas supplied to the internal space of the chamber in order to obtain the desired gas processing results for the wafer to be processed.

[0009] Patent Document 1 discloses a substrate processing system equipped with a flow rate measurement system that measures the flow rate of gas supplied to the internal space of a chamber body. According to the flow rate measurement method described in Patent Document 1, a build-up method is used as one of the methods for measuring gas flow rate, and by supplying gas to a gas flow path with a known volume, the gas flow rate is measured based on the pressure rise rate in the gas flow path associated with the gas supply, the temperature in the gas flow path, and the volume of the gas flow path.

[0010] In the build-up method, before supplying gas to the gas flow passage, the inside of the flow measurement system must be evacuated and vacuumed (reduced pressure). At this time, a turbo molecular pump (TMP) provided downstream of a chamber communicating with the system may be used to perform the vacuuming. To check whether the vacuuming is complete, a pressure sensor in a flow measurement unit provided in the flow measurement device can be used. Due to the piping configuration, a chamber, a gas box, and a measurement piping are provided between the TMP and the flow measurement unit. Therefore, by performing the vacuuming using the TMP, the entire system can be efficiently evacuated, and the completion of the vacuuming can be accurately confirmed by a pressure sensor provided in the flow measurement unit.

[0011] Here, the flow rate measurement method described in Patent Document 1 includes a process of starting the supply of gas from a flow rate control device after evacuation, and opening a valve provided between the flow rate measurement unit and an exhaust unit provided downstream (exhaust side) of the flow rate measurement unit to communicate with each other. However, the inventors of the present invention have found that when evacuation is performed using a TMP, a pressure difference may occur between the flow rate measurement unit and the exhaust unit, causing the flow rate measurement unit to be in negative pressure, and if the above process is performed in a state where the pressure difference occurs, exhaust gas may flow from the exhaust unit to the flow rate measurement device, making it impossible to perform appropriate flow rate measurement thereafter. Therefore, there is room for improvement in the conventional flow rate measurement method so that flow rate measurement can be performed appropriately even when evacuation is performed using a TMP.

[0012] The technology disclosed herein has been made in consideration of the above circumstances, and appropriately measures the flow rate of a gas output from a flow rate controller in a substrate processing system. Hereinafter, a wafer processing system as a substrate processing system according to an embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are denoted by the same reference numerals, and duplicated descriptions will be omitted.

[0013] <Wafer Processing System Configuration> 1 is a plan view showing an outline of the configuration of a wafer processing system 1 according to this embodiment. In the wafer processing system 1, a desired gas process, such as an etching process, a film forming process, or a cleaning process, is performed on a wafer W as a substrate.

[0014] 1, the wafer processing system 1 has an atmospheric section 10 and a reduced pressure section 11 that are integrally connected via load lock modules 20 and 21. The atmospheric section 10 includes an atmospheric module that performs a desired process on the wafer W in an atmospheric pressure atmosphere. The reduced pressure section 11 includes a reduced pressure module that performs a desired process on the wafer W in a reduced pressure atmosphere.

[0015] The load lock modules 20 and 21 are connected to a loader module 30 (to be described later) in the atmospheric section 10 via gate valves 20a and 21a, respectively. The load lock modules 20 and 21 are also connected to a transfer module 50 (to be described later) in the reduced pressure section 11 via gate valves 20b and 21b, respectively. The load lock modules 20 and 21 are configured to temporarily hold a wafer W. The load lock modules 20 and 21 are also configured so that the interior can be switched between an atmospheric pressure atmosphere and a reduced pressure atmosphere (vacuum state).

[0016] The atmospheric section 10 has a loader module 30 that transports wafers W under atmospheric pressure. The loader module 30 is provided with a plurality of (for example, five) load ports 32 for mounting FOUPs 31 capable of storing a plurality of wafers W, and the above-mentioned load lock modules 20 and 21. The loader module 30 may also be provided with an orienter module (not shown) that adjusts the horizontal orientation of the wafer W, a storage module (not shown) that stores a plurality of wafers W, and the like.

[0017] A wafer transfer mechanism 40 is provided inside the loader module 30 and configured to be movable on a guide rail 41 extending into the loader module 30. The wafer transfer mechanism 40 has a transfer arm 42 that holds and moves a wafer W. The transfer arm 42 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. The wafer transfer mechanism 40 is configured to be able to transfer the wafer W to the FOUP 31 of the load port 32 and the load lock modules 20, 21.

[0018] The decompression unit 11 has a transfer module 50 that transports the wafer W under a decompressed atmosphere. The transfer module 50 is provided with a plurality of chambers 60 (for example, six chambers) for performing desired gas processing such as etching, film formation, cleaning, etc. on the wafer W depending on the purpose, and the load lock modules 20 and 21 described above. The chambers 60 are connected to the transfer module 50 via a gate valve 61. The number of chambers 60 connected to the transfer module 50 is not limited to the example shown in the figure, and can be determined arbitrarily.

[0019] A wafer transfer mechanism 70 is provided inside the transfer module 50 and configured to be movable on a guide rail 71 extending inside the transfer module 50. The wafer transfer mechanism 70 has a transfer arm 72 that holds and moves a wafer W. The transfer arm 72 is configured to be movable horizontally, vertically, around a horizontal axis, and around a vertical axis. The wafer transfer mechanism 70 is configured to be able to transfer the wafer W to any of the chambers 60 and the load lock modules 20, 21.

[0020] In the transfer module 50, the transfer arm 72 receives the wafer W held in the load lock module 20 and transfers it to an arbitrary chamber 60. In addition, the transfer arm 72 holds the wafer W that has been subjected to the desired processing in the chamber 60 and transfers it to the load lock module 21.

[0021] The decompression unit 11 is provided with a gas supply mechanism 100 for supplying gas to each of the chambers 60. The gas supply mechanism 100 includes a plurality of gas boxes 110 (for example, six gas boxes corresponding to each of the chambers 60) each housing a gas control unit for controlling the supply of gas to the chambers 60, a main gas unit 120 as a gas supply unit having at least one gas source provided on the primary side (upstream side) of the gas box 110 (chamber 60), and a flow rate measurement unit 130 and measurement piping 131 for measuring the flow rate of gas supplied to the chamber 60. In this specification, the flow rate measurement unit 130 and measurement piping 131 are collectively referred to as the "flow rate measurement device" according to the technology of the present disclosure. A detailed configuration of the gas supply mechanism 100 will be described later.

[0022] The wafer processing system 1 described above is provided with a control unit 200. The control unit 200 is, for example, a computer equipped with a CPU, a memory, and the like, and has a program storage unit (not shown). The program storage unit stores a program for controlling gas processing of the wafer W in the wafer processing system 1. The program storage unit further stores a program for controlling a supply operation of a processing gas, which will be described later. The above program may be recorded in a computer-readable storage medium H and installed from the storage medium H to the control unit 200. The storage medium H may be temporary or non-temporary.

[0023] Next, an example of a detailed configuration of the above-mentioned gas supply mechanism 100 will be described. Fig. 2 is a schematic diagram showing a piping system constituting the gas flow path of the gas supply mechanism 100. In the following description, as described above, the main gas unit 120 side in the gas flow direction may be referred to as the primary side (upstream side), and the exhaust unit 150 side in the gas flow direction, which will be described later, may be referred to as the secondary side (downstream side). In Fig. 2, some of the six chambers 60 and gas boxes 110 arranged in the wafer processing system 1 are omitted in order to prevent the illustration from becoming complicated.

[0024] The main gas unit 120 includes a gas source 121 and a flow controller 122 for supplying one or more gases to each gas box 110. In one embodiment, the main gas unit 120 is configured to supply one or more gases from the corresponding gas source 121 to the gas box 110 via the corresponding flow controller 122. Each flow controller 122 may include, for example, a mass flow controller or a pressure-controlled flow controller. Gases supplied from the main gas unit 120 include, for example, a process gas used for wafer processing in the chamber 60, and a dry gas used for opening and closing a valve, which will be described later.

[0025] A plurality of gas boxes 110 (six gas boxes 110 in this embodiment corresponding to the respective chambers 60 as described above) are connected to the downstream side of the main gas unit 120 via a connection pipe 123. Further, a valve 123a is arranged in the connection pipe 123 corresponding to each gas box 110, and the gas supply from the main gas unit 120 to each gas box 110 can be arbitrarily switched by opening and closing the valve 123a.

[0026] The gas box 110 is provided with a flow rate controller 111 for controlling the flow rate of the process gas to each of the corresponding chambers 60. A plurality of flow rate controllers 111 may be provided according to the type of gas supplied from the main gas unit 120. A flow rate controller primary valve 111a is disposed on the primary side of the flow rate controller 111, and the gas supply from the main gas unit 120 to each flow rate controller 111 can be arbitrarily switched by opening and closing the flow rate controller primary valve 111a. A flow rate controller secondary valve 111b is disposed on the secondary side of the flow rate controller 111, and the gas supply from the flow rate controller 111 to the secondary side can be arbitrarily switched.

[0027] The downstream side of the gas box 110 is connected to the corresponding chamber 60 via a connection pipe 112. A first output valve 112a is disposed in the connection pipe 112, and the gas supply from the gas box 110 to the chamber 60 can be arbitrarily switched by opening and closing the first output valve 112a.

[0028] Further, downstream of the gas box 110, a flow rate measuring unit 130 is connected via a measurement pipe 131, which branches off from the connection pipe 112. A second output valve 131a is disposed in the measurement pipe 131, and the gas supply from the gas box 110 to the flow rate measuring unit 130 can be arbitrarily switched by opening and closing the second output valve 131a.

[0029] In the gas box 110 according to the present embodiment, when gas is supplied from one flow rate controller 111, for example, when processing gas is supplied to the chamber 60 for the purpose of wafer processing, the first output valve 112a is opened and the second output valve 131a is closed, so that the processing gas is supplied to the chamber 60 through the connection pipe 112. On the other hand, when gas is supplied to the flow rate measuring unit 130 for the purpose of measuring the gas flow rate, the second output valve 131a is opened and the first output valve 112a is closed, so that the gas is supplied to the flow rate measuring unit 130 through the measurement pipe 131.

[0030] As described above, a desired process gas according to the purpose of the wafer processing is supplied into the chamber 60 via the connection pipe 112. In the chamber 60, the supplied process gas is used to perform a desired gas process such as an etching process, a film forming process, or a cleaning process on the wafer W.

[0031] A turbo molecular pump 62 as a first exhaust mechanism in this embodiment and a first exhaust pipe 64 connected to the downstream side of the turbo molecular pump 62 are provided on the downstream side (exhaust side) of the chamber 60. The process gas supplied to the inside of the chamber 60 is exhausted by the turbo molecular pump 62 through the first exhaust pipe 64 to an exhaust unit 150 described below. An exhaust valve 64a is disposed on the first exhaust pipe 64, and an exhaust operation of the process gas from the chamber 60 by the turbo molecular pump 62 can be controlled by opening and closing the exhaust valve 64a.

[0032] The flow rate measurement unit 130 includes a plurality of sensors, for example, two pressure sensors 132 and 133 in this embodiment, that measure the internal pressure of the flow rate measurement unit 130, and a temperature sensor 134 that measures the internal temperature of the flow rate measurement unit 130. The pressure measurement range of the pressure sensors 132 and 133 can be determined arbitrarily, but for example, in order to widen the pressure measurement range in the flow rate measurement unit 130, it is preferable to use one sensor that can measure in a high pressure range and the other sensor that can measure in a low pressure range.

[0033] The primary side of the flow rate measuring unit 130 is connected to the measurement pipe 131 via a flow rate measuring unit primary valve 130a, and is configured such that gas from the gas box 110 can be introduced into the flow rate measuring unit 130 by opening the flow rate measuring unit primary valve 130a. In addition, the secondary side of the flow rate measuring unit 130 is connected to a calibration system 140 (described later) via a flow rate measuring unit secondary valve 130b.

[0034] In this embodiment, the flow rate measurement unit 130 is configured to form a flow path therein and to allow gas to flow from the gas box 110. Therefore, the inside of the flow rate measurement unit 130 in which the pressure sensors 132, 133 and the temperature sensor 134 are provided is the region between the flow rate measurement unit primary valve 130a and the flow rate measurement unit secondary valve 130b, and refers to the internal space of the flow rate measurement unit 130 itself which forms the gas flow path.

[0035] In this embodiment, the measurement pipe 131 is configured to form a flow path therein and to allow the gas from the gas box 110 to flow therethrough. In a gas flow rate measurement method according to this embodiment, which will be described later, the gas from the gas box 110 is sealed in the flow rate measurement unit 130 via the measurement pipe 131, and the rate of increase in the internal pressure of the measurement pipe 131 and the flow rate measurement unit 130 is measured, and the gas flow rate is measured using the rate of increase.

[0036] The calibration system 140 checks the volume of the flow rate measurement unit 130 and / or calibrates the pressure sensors 132, 133 or the temperature sensor provided in the flow rate measurement unit 130. The calibration system 140 includes a reference device piping 141 and a reference device 142. A reference device valve 141a is disposed in the reference device piping 141, and the supply of gas to the reference device 142 can be arbitrarily controlled by opening and closing the reference device valve 141a.

[0037] The upstream side of the reference pipe 141 is connected to the flow rate measuring unit 130 via the flow rate measuring unit secondary valve 130b as described above. The downstream side of the reference pipe 141 is connected to the second exhaust pipe 143, i.e., the exhaust unit 150 described below, via the calibration valve 140a. An exhaust valve 143a is disposed in the second exhaust pipe 143, and the communication between the second exhaust pipe 143 and the first exhaust pipe 64 can be arbitrarily switched by opening and closing the exhaust valve 143a.

[0038] The exhaust unit 150 includes the first exhaust pipe 64 and the second exhaust pipe 143, and is configured so that the second exhaust pipe 143 and the first exhaust pipe 64 join at a joining point 152. The exhaust unit 150 further includes a second exhaust mechanism 154 configured to exhaust gas from the first exhaust pipe 64 and the second exhaust pipe 143 downstream of the joining point 152, and at least one decontamination device 156 for decontaminating the exhaust gas downstream of the second exhaust mechanism 154. The second exhaust mechanism 154 is provided corresponding to each of the multiple chambers 60 arranged in the wafer processing system 1, and the second exhaust mechanism 154 may include, for example, a vacuum pump such as a turbo molecular pump or a dry pump, or a combination thereof.

[0039] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. In addition, elements in different embodiments can be combined to form other embodiments.

[0040] <Wafer processing method> The wafer processing system 1 and the gas supply mechanism 100 according to the present embodiment are configured as described above. Next, a wafer processing method according to the present embodiment, including a method for measuring a gas flow rate using the flow rate measuring unit 130, will be described with reference to the drawings.

[0041] Fig. 3 is a partial diagram of the piping system shown in Fig. 2, depicting only a portion related to measurement of the flow rate of the process gas to be measured, and omitting other components. Fig. 3 depicts only a flow rate controller 111 that supplies the gas to be measured, a gas box 110 having the flow rate controller 111, and a chamber 60 to which the gas box 110 is connected, and omits other flow rate controllers 111, other gas boxes 110, and other chambers 60. Other components in Fig. 3 have the same functions and configurations as those in Fig. 2.

[0042] Fig. 4 is a flow diagram showing a series of steps in a method for measuring a gas flow rate according to an embodiment. Fig. 5 shows the timing of opening and closing various valves in the method for measuring a gas flow rate shown in Fig. 4. In Fig. 5, the horizontal axis shows time, and the vertical axis shows the pressure measured by the pressure sensor of the flow rate measurement unit 130, and the open and closed states of the flow rate controller secondary valve 111b, the flow rate measurement unit primary valve 130a, the flow rate measurement unit secondary valve 130b, and the calibration valve 140a. In the following description, other valves (e.g., output valves, exhaust valves, etc.) not shown in the timing diagram of Fig. 5 are assumed to be closed unless otherwise specified.

[0043] In the following explanation, an example will be given of measuring the flow rate of gas output from one flow rate controller 111 arranged in one gas box 110 shown in FIG. 3 out of the six gas boxes 110 in the wafer processing system 1 shown in FIG. 2. However, even if gas is supplied from another gas box 110 arranged in the wafer processing system 1, the gas flow rate can be measured in a similar manner.

[0044] In this embodiment, prior to measuring the gas flow rate, the reliability of the gas flow rate measurement performed using the flow rate measurement unit 130 may be confirmed. Specifically, calibration of the pressure sensors 132, 133 and temperature sensor 134 of the flow rate measurement unit 130 (step STA in FIG. 4), and verification of the internal volume V of the measurement pipe 131 and the flow rate measurement unit 130 (step STB in FIG. 4) may be performed.

[0045] The methods of these steps STA and STB are not particularly limited as long as they can appropriately check and calibrate the various sensors and check the internal volume V. Furthermore, these steps STA and STB may be omitted as appropriate.

[0046] When measuring the gas flow rate from the gas box 110, first, the inside of the gas box 110, the measurement pipe 131, and the flow measurement unit 130 are evacuated (step ST1 in FIG. 4 and FIG. 5). More specifically, in step ST1, the flow controller secondary valve 111b of the flow controller 111, the first output valve 112a, the second output valve 231a, and the flow measurement unit primary valve 130a are opened, and the flow measurement unit secondary valve 130b is closed. In this state, the exhaust valve 64a is further opened, whereby the inside of the gas box 110, the measurement pipe 131, and the flow measurement unit 130 are evacuated by the turbo molecular pump 62.

[0047] During the above-mentioned vacuum drawing, the flow measurement unit secondary valve 130b is closed, thereby stopping the flow of process gas between the flow measurement unit 130 and the second exhaust pipe 143, so that the exhaust gas filling the second exhaust pipe 143 does not flow into the calibration system 140 or the flow measurement unit 130.

[0048] By the above-mentioned evacuation, the gas filling the flow path (dashed line in the figure) from the chamber 60 to the secondary valve 130b of the flow measurement unit is exhausted by the turbo molecular pump 62 in the direction shown by the thick arrow in Fig. 3 toward the first exhaust pipe 64. The gas in the first exhaust pipe 64 is exhausted by the second exhaust mechanism 154. As a result, the flow path from the chamber 60 to the secondary valve 130b of the flow measurement unit, shown by the dashed line in Fig. 3, is evacuated. The state of the flow measurement device when evacuation is completed is referred to as the first state.

[0049] After the evacuation is completed, the flow rate controller primary valve 111a is opened, and the process gas to be measured is supplied to the flow rate measurement device via the flow rate controller 111 (step ST2 in FIG. 4 and FIG. 5). That is, in step ST2, the process gas to be measured is supplied to the flow rate measurement device in the first state at a pressure P A In this specification, the supply of the processing gas to the flow rate measuring device in step ST2 is referred to as "pre-delivery." The flow rate of the processing gas in the pre-delivery is referred to as the pre-delivery flow rate Q A This is called the advance flow rate QA is the flow rate Q of the process gas supplied from the gas box 110 to the flow rate measuring device in the flow rate measuring steps (steps ST3 to ST15 in FIGS. 4 and 5) described later. B (Hereinafter, set flow rate Q B ) may be different from the flow rate.

[0050] Furthermore, the first-out flow rate is Q A and the time required for first-out t A and pressure P A and the total volume V of the measurement pipe 131 and the flow rate measurement unit 130. A and can be determined and executed so as to satisfy the following formula (1). Q A ×t A =P A ×V A ×R / T A (1)

[0051] In equation (1), R is the gas constant and T A is the absolute temperature inside the flow measurement unit 130. A The room temperature in the flow rate measuring unit 130 may be used as the pre-transport flow rate Q A may be any flow rate, but from the viewpoint of shortening the time required to measure the flow rate, it is preferable to set it to the maximum flow rate that the flow rate controller 111 can supply to the flow measurement device.

[0052] Based on equation (1), any advance flow rate Q A For time t A By first discharging the flow rate measuring unit 130, the inside of the flow rate measuring unit 130 is heated to a pressure P A In addition, the actual pressure inside the flow rate measuring unit 130 is a pressure P A In this case, the average value of the measured values ​​by the two pressure sensors 132 and 133 of the flow rate measuring unit 130 is obtained, and the average value is a pressure P A It is sufficient to confirm that the above is true.

[0053] Here, the pressure P A is the theoretical pressure P inside the second exhaust pipe 143 after the evacuation is completed. B It is determined to be higher than

[0054] The theoretical pressure P inside the second exhaust pipe 143 B is the time required for evacuation in step ST1. VAC At time t VAC and the exhaust capacity (flow rate value) Q of the turbo molecular pump 62. TMP and the total volume V of the first exhaust pipe 64 and the second exhaust pipe 143. EXH and the exhaust capacity (flow rate value) Q of the second exhaust mechanism 154 DP Specifically, the theoretical pressure P B can be determined so as to satisfy the following formula (2). (Q TMP -Q DP )×t VAC =P B ×V EXH ×R / T EXH (2)

[0055] In equation (2), R is the gas constant and T EXH is the absolute temperature inside the first exhaust pipe 64 and the second exhaust pipe 143. EXH Alternatively, the room temperature in the exhaust unit 150 may be used.

[0056] From equation (2), the exhaust capacity Q of the turbo molecular pump 62 is TMP is the exhaust capacity Q of the second exhaust mechanism 154 DP If the pressure exceeds the theoretical pressure P, the pressure in the first exhaust pipe 64 and the second exhaust pipe 143 increases due to the execution of the evacuation. B It becomes.

[0057] According to the first-out process in step ST2, the pressure P A is the theoretical pressure P B This state in the flow measurement device is referred to as the second state.

[0058] Subsequently, the flow rate measuring unit secondary valve 130b is opened, and the flow rate of the process gas to be measured is measured. Specifically, first, the gas is supplied from the flow rate controller 111 to the measurement pipe 131 at a set flow rate Q B (step ST3 in FIGS. 4 and 5). Next, the flow rate controller secondary valve 111b and the flow rate measurement unit secondary valve 130b are closed (step ST4 in FIGS. 4 and 5). That is, in step ST4, a third state is formed in which the gas output from the flow rate controller 111 of the gas box 110 is sealed between the flow rate controller secondary valve 111b and the flow rate measurement unit secondary valve 130b, i.e., inside the gas box 110, downstream of the flow rate controller secondary valve 111b, in the measurement pipe 131 and the flow rate measurement unit 130.

[0059] In the third state, the internal pressure P1 of the flow measurement unit 130 is acquired (step ST5 in FIG. 4). The internal pressure P1 may be an average value of the measured values ​​by the two pressure sensors 132, 133 of the flow measurement unit 130. Note that, in step ST5, it is desirable that the measured values ​​are acquired by the pressure sensors 132, 133 when the internal pressure P1 of the measurement pipe 131 and the flow measurement unit 130 is stable. The internal pressure P1 can be determined to be stable, for example, when the amount of fluctuation is equal to or less than a desired threshold value.

[0060] When the internal pressure P1 of the flow rate measuring unit 130 is acquired, the flow rate controller secondary valve 111b and the flow rate measuring unit secondary valve 130b, which were closed in step ST4, are then opened (step ST6 in FIGS. 4 and 5). Next, the flow rate measuring unit secondary valve 130b is closed, and the supply of gas from the flow rate controller 111 is continued in this state, forming a fourth state in which the internal pressure of the measurement pipe 131 and the flow rate measuring unit 130 increases (step ST7 in FIGS. 4 and 5).

[0061] When the internal pressure of the measurement pipe 131 and the flow rate measurement unit 130 is increased to a desired value, the flow rate controller secondary valve 111b is then closed (step ST8 in FIG. 4 and FIG. 5). That is, in step ST8, a fifth state is formed in which the gas output from the flow rate controller 111 of the gas box 110 is sealed between the flow rate controller secondary valve 111b and the flow rate measurement unit secondary valve 130b, that is, inside the gas box 110 on the downstream side of the flow rate controller secondary valve 111b, in the measurement pipe 131 and the flow rate measurement unit 130.

[0062] In the fifth state, the internal pressure P2 and internal temperature T2 of the flow measurement unit 130 are acquired (step ST9 in FIG. 4). The internal pressure P2 may be an average value of the measured values ​​by the two pressure sensors 132, 133 of the flow measurement unit 130. Note that in step ST9, it is desirable to acquire measured values ​​by the pressure sensors 132, 133 and the temperature sensor 134 when the internal pressure P2 and internal temperature T2 of the measurement pipe 131 and the flow measurement unit 130 are stable. The internal pressure P2 and internal temperature T2 can be determined to be stable, for example, when the amount of fluctuation is equal to or less than a desired threshold value.

[0063] When the internal pressure P2 and internal temperature T2 of the flow measurement unit 130 are acquired, the flow measurement unit secondary valve 130b is then opened, and the flow measurement unit primary valve 130a and the calibration valve 140a are closed (step ST10 in FIG. 4 and FIG. 5). That is, in step ST10, a sixth state is formed in which the gas sealed in the measurement pipe 131 and the flow measurement unit 130 in step ST8 is sealed between the flow measurement unit secondary valve 130b and the calibration valve 140a, that is, at least a part of the gas sealed in the measurement pipe 131 and the flow measurement unit 130 in step ST8 is discharged to the calibration system 140.

[0064] In this embodiment, at least a portion of the gas sealed in the flow measurement unit 130 is discharged in step ST10, but the gas sealed in the flow measurement unit 130 may be completely discharged via the calibration system 140.

[0065] Next, the flow rate measuring unit secondary valve 130b is closed to form a seventh state in which the flow rate measuring unit 130 and the calibration system 140 are disconnected (step ST11 in FIGS. 4 and 5). In this embodiment, the gas sealed inside the flow rate measuring unit 130 in the fifth state (step ST8) is partially discharged, in other words, the seventh state is formed without the sealed gas being completely discharged. Therefore, the time required to form the seventh state (step ST11) from the fifth state (step ST8) is shortened.

[0066] Although not shown in the figure, the internal pressure of the flow measuring unit 130 may be reduced by adding a step of opening the calibration valve 140a after step ST11 and repeating steps from step ST10 to the opening of the calibration valve 140a.

[0067] In the seventh state, the internal pressure P3 of the flow measurement unit 130 is acquired (step ST12 in FIG. 4). The internal pressure P3 may be an average value of the measured values ​​by the two pressure sensors 132, 133 of the flow measurement unit 130. Note that, in step ST12, it is desirable that the measured values ​​are acquired by the pressure sensors 132, 133 when the internal pressure P2 of the measurement pipe 131 and the flow measurement unit 130 is stable. The internal pressure P3 can be determined to be stable, for example, when the amount of fluctuation is equal to or less than a desired threshold value.

[0068] Once the internal pressure P3 of the flow measurement unit 130 has been acquired, the flow measurement unit primary valve 130a is then opened, thereby forming an eighth state in which at least a portion of the gas sealed in the measurement piping 131 in step ST8 flows in and the internal pressure of the flow measurement unit 130 increases (step ST13 in Figures 4 and 5).

[0069] Thereafter, as time passes, a ninth state is formed in which the gas flows from the measurement pipe 131 into the flow rate measurement unit 130, i.e., the internal pressure of the flow rate measurement unit 130 becomes stable. The internal pressure can be determined to be stable, for example, when the amount of fluctuation is equal to or less than a desired threshold value. In addition, in this ninth state, the internal pressure P4 of the flow rate measurement unit 130 is acquired (step ST14 in FIG. 4). The internal pressure P4 may be an average value of the measured values ​​by the two pressure sensors 132, 133 of the flow rate measurement unit 130.

[0070] When the internal pressure P4 of the flow rate measuring unit 130 is acquired, the gas flow rate Q output from the flow rate controller 111 is C (Hereinafter, measured flow rate Q C ) is calculated, for example, by the following formula (3) (step ST15 in FIG. 4). Q C =(P2-P1) / Δt×(1 / R)×[(Vst / Tst)+(V / T2)× (P2-P3) / (P2-P4)] (3) Here, P1 to P4 are the measured values ​​by the pressure sensors 132 and 133, T2 is the measured value by the temperature sensor 134, V is the internal volume of the measurement pipe 131 and the flow measurement unit 130, Vst is the volume of the pipe downstream of the flow controller 111 in the gas box 110, Tst is the internal temperature of the pipe downstream of the flow controller 111 in the gas box 110, Δt is the time required for the internal pressure to increase in the fourth state (step ST7), and R is the gas constant. Note that (Vst / Tst) can be omitted as appropriate.

[0071] In addition, the measured flow rate Q C The above formula (3) for calculating the measured flow rate Q is an example, and other calculation formulas can be used as appropriate. C may be calculated.

[0072] Thereafter, the measured flow rate Q output from the flow rate controller 111 COnce calculated, the calibration valve 140a and the flow controller secondary valve 111b are sequentially opened to complete a series of gas flow measurements made using the flow measurement unit 130.

[0073] The wafer processing including the flow rate measurement according to this embodiment is carried out as described above.

[0074] Here, in the first state where evacuation is completed, the first exhaust pipe 64 and the second exhaust pipe 143 shown by the solid lines in Fig. 3 are filled with exhaust gas exhausted by the above-mentioned evacuation. The exhaust gas in the first exhaust pipe 64 is sequentially exhausted by the second exhaust mechanism 154. On the other hand, depending on the exhaust capacity of the turbo molecular pump 62 and the second exhaust mechanism 154, for example, a first state may occur in which a pressure difference occurs such that the pressure inside the second exhaust pipe is higher than the pressure inside the flow measurement unit 130.

[0075] As a result of intensive research by the present inventors, it was found that the theoretical value P B is the pressure P inside the flow measuring unit 130 A It has been found that in the first state in which the above pressure difference has occurred, if the flow measurement unit secondary valve 130b, the calibration valve 140a, and the exhaust valve 143a are opened to perform another process, the above pressure difference may cause exhaust gas in the second exhaust pipe 143 to flow into the flow measurement unit 130, and flow measurement may not be performed properly.

[0076] In this embodiment, in step ST2, a pre-delivery is performed, the process gas to be measured is filled into the flow measurement device, and the pressure P A The theoretical pressure P B The pressure difference is eliminated by forming a second state in which the pressure is higher than the first state, thereby making it possible to appropriately measure the flow rate even when evacuation is performed by the turbo molecular pump 62 as the first exhaust mechanism.

[0077] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0078] 1. Wafer Processing System 60. Chamber 62. Turbomolecular pump 64. First exhaust pipe 110 Gas Box 111 Flow Controller 111b Flow Controller Secondary Valve 130 Flow Measuring Unit 143 Second exhaust pipe W wafer

Claims

1. 1. A substrate processing system, comprising: a plurality of chambers for processing substrates in desired process gases; a plurality of gas boxes for supplying the process gas to each of the plurality of chambers; a flow rate measuring device for measuring a flow rate of the process gas supplied from the plurality of gas boxes; an exhaust unit connected to the plurality of chambers and the flow rate measuring device; A control unit configured to be able to execute a substrate processing method; Equipped with a plurality of first exhaust pipes connected to the plurality of chambers, respectively; a second exhaust pipe connected to the flow rate measuring device and the first exhaust pipe, each of the plurality of chambers includes an exhaust mechanism that exhausts the process gas to a corresponding one of the first exhaust pipes; The flow measurement device includes a flow measurement unit; The substrate processing method includes: (a) stopping the flow of the process gas between the flow measurement device and the second exhaust pipe, and forming a first state in which the flow measurement device is evacuated by one of the exhaust mechanisms connected to one of the chambers; (b) after the step (a), supplying the process gas to the flow measurement device from one of the gas boxes corresponding to one of the chambers to form a second state in which at least the pressure inside the flow measurement unit is higher than the pressure inside the second exhaust pipe, and allowing the process gas to flow between the flow measurement device and the second exhaust pipe in the second state; (c) measuring the flow rate of the process gas; A substrate processing system comprising:

2. 2. The substrate processing system of claim 1, wherein in the step (b), when a flow rate of the processing gas supplied from the one gas box to the flow measuring device is Q and a time for which the processing gas is supplied from the one gas box to the flow measuring device is t, the flow rate Q and the time t satisfy the following formula (1): Q×t=V×P×R / T...(1) where V is the total volume filled with the process gas in the flow measuring device, P is the pressure inside the flow measuring unit in the second state, R is the gas constant, and T is the absolute temperature in the flow measuring device.

3. 3. The substrate processing system according to claim 2, wherein in the step (b), a flow rate Q of the processing gas supplied from the one gas box to the flow rate measuring device is a maximum flow rate that can be supplied from the one gas box.

4. 1. A method for processing a substrate in a substrate processing system, comprising: The substrate processing system includes: a plurality of chambers for processing substrates in desired process gases; a plurality of gas boxes for supplying the process gas to each of the plurality of chambers; a flow rate measuring device for measuring a flow rate of the process gas supplied from the plurality of gas boxes; an exhaust unit connected to the plurality of chambers and the flow rate measuring device; Equipped with The exhaust unit includes: a plurality of first exhaust pipes connected to the plurality of chambers, respectively; a second exhaust pipe connected to the flow rate measuring device and the first exhaust pipe, each of the plurality of chambers includes an exhaust mechanism that exhausts the process gas to a corresponding one of the first exhaust pipes; The flow measurement device includes a flow measurement unit; The substrate processing method includes: (a) stopping the flow of the process gas between the flow measurement device and the second exhaust pipe, and forming a first state in which the flow measurement device is evacuated by one of the exhaust mechanisms connected to one of the chambers; (b) after the step (a), supplying the process gas to the flow measurement device from one of the gas boxes corresponding to one of the chambers to form a second state in which at least the pressure inside the flow measurement unit is higher than the pressure inside the second exhaust pipe, and allowing the process gas to flow between the flow measurement device and the second exhaust pipe in the second state; (c) measuring the flow rate of the process gas; A method for processing a substrate, comprising:

5. 5. The substrate processing method of claim 4, wherein in the step (b), when a flow rate of the processing gas supplied from the one gas box to the flow measuring device is Q and a time for which the processing gas is supplied from the one gas box to the flow measuring device is t, the flow rate Q and the time t satisfy the following formula (1): Q×t=V×P×R / T...(1) where V is the total volume filled with the process gas in the flow measuring device, P is the pressure inside the flow measuring unit in the second state, R is the gas constant, and T is the absolute temperature in the flow measuring device.

6. 6. The substrate processing method according to claim 5, wherein in the step (b), a flow rate Q of the processing gas supplied from the one gas box to the flow rate measuring device is a maximum flow rate that can be supplied from the one gas box.

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