JP6748586B2 - Gas supply system, substrate processing system and gas supply method - Google Patents

Description

The present invention relates to a gas supply system, a substrate processing system and a gas supply method.

Patent Document 1 discloses a pressure type flow rate control device. The pressure type flow rate control device includes a control valve for controlling a gas flow rate to a predetermined amount, an orifice provided downstream of the control valve, a temperature sensor and a pressure sensor arranged between the control valve and the orifice, and a sensor. And a control circuit for controlling the opening/closing amount of the control valve based on the detected value and the target value. In the pressure type flow rate control device, the control circuit calculates the temperature-corrected flow rate based on the sensor detection value. Then, the control circuit compares the calculated flow rate with the target value, and controls the control valve so that the difference becomes small.

International Publication No. 2015/064035

By the way, in the substrate processing process, a plurality of gases may be used for processing. For example, the gas from a plurality of gas sources may be merged and supplied to the chamber, or the gas to be used may be switched for each step.

In order to realize such a process, for example, as shown in FIG. 28, an on-off valve 102 is arranged on the downstream side of a pressure type flow rate control device FC3 that controls the gas flow rate of the gas supply source 100, and mixing is performed. It is conceivable to utilize the opening/closing valve 102 for selecting a gas or switching the gas supplied to the chamber. Further, for example, as shown in FIG. 29, it is conceivable to join the flow path 104 for the second gas with the flow path 103 for the first gas at the connection point 105 and supply the mixed gas to the chamber. ..

However, in the configuration shown in FIG. 28, when the open/close valve 102 is closed, the gas remains in the flow path 103 between the orifice 101 and the open/close valve 102. Since the pressure and the flow rate of such residual gas cannot be controlled, when the opening/closing valve 102 is opened, the gas is supplied to the chamber in a state where the flow rate is not controlled. Further, in the configuration shown in FIG. 29, when the pressure of the first gas flowing through the flow path 103 is higher than the pressure of the second gas flowing through the flow path 104, the second gas flows between the opening/closing valve 102A and the connection point 105. It may take time to fill the flow path between them. Thus, there is room for improvement in the gas supply system in order to carry out the process by controlling a plurality of gases.

A gas supply system according to one aspect of the present invention is a gas supply system for supplying gas to a chamber of a substrate processing apparatus, the first flow path connecting a first gas source of a first gas and the chamber, A second flow path connecting the second gas source of the two gases and the first flow path, a control valve provided in the second flow path for controlling the flow rate of the second gas to a predetermined amount, and a control valve downstream of the control valve. Of the second gas that is provided at the connection point between the orifice provided at the end of the second flow path and the end of the first flow path and the end of the second flow path and is supplied from the outlet of the orifice to the first flow path. An opening/closing valve that controls the supply timing, an exhaust mechanism that is connected to the flow passage between the control valve and the orifice of the second flow passage, and that exhausts the second gas, and the control valve, the opening/closing valve, and the exhaust mechanism operate And a controller.

In this gas supply system, an orifice is provided downstream of the control valve at the end of the second flow path, and an opening/closing valve is provided at the connection point between the first flow path and the end of the second flow path. That is, since the orifice and the opening/closing valve are arranged at the connection point between the first flow path and the end of the second flow path, the flow path from the orifice to the opening/closing valve can be minimized. Accordingly, when the opening/closing valve is opened, it is possible to prevent the gas remaining in the flow path from the orifice to the opening/closing valve from being supplied to the chamber in a state where the flow rate is not controlled. Furthermore, since the open/close valve is provided at the connection point between the first flow path and the end of the second flow path, the flow path from the open/close valve to the connection point can be minimized. Thereby, even when the pressure of the gas flowing through the first flow path is higher than the pressure of the gas flowing through the second flow path, the second gas fills the flow path between the on-off valve and the connection point. It is possible to avoid taking time. Further, since the exhaust mechanism for exhausting the second gas is connected to the flow passage between the control valve and the orifice in the second flow passage, for example, by closing the open/close valve and operating the exhaust mechanism, The flow path between the control valve and the orifice can be filled with a gas having a predetermined target pressure while the supply to the chamber is stopped. For this reason, it is possible to omit the time from when the opening/closing valve is opened until the flow path between the control valve and the orifice is filled with the gas having the predetermined target pressure, so that the response is excellent.

In one embodiment, the opening/closing valve may have a sealing member that is pressed against the orifice so as to seal the outlet of the orifice during the closing control and is separated from the orifice during the opening control. With this configuration, the outlet of the orifice can be opened and closed.

In one embodiment, the on-off valve includes a cylinder that fixedly supports the sealing member, a biasing member that elastically biases the cylinder in a direction in which the sealing member is pressed against the orifice, and a direction opposite to the pressing direction. And a drive unit for moving the cylinder. When configured in this way, the drive unit can move the sealing member pressed against the orifice by the biasing member via the cylinder in the direction opposite to the pressing direction to open the outlet of the orifice. it can.

In one embodiment, the orifice and the opening/closing valve may be arranged downstream of the inlet block provided in the chamber. By locating the orifice and the opening/closing valve on the downstream side of the inlet block, that is, on the chamber side of the inlet block, the gas can be controlled at a position closer to the chamber as compared with the case of being positioned on the upstream side of the inlet block. Therefore, the responsiveness of the gas supplied to the chamber can be improved.

In one embodiment, the orifice and the opening/closing valve may be arranged upstream of the inlet block provided in the chamber. In such a configuration, the constituent elements located from the control valve to the opening/closing valve can be unitized, so that each constituent element can be handled easily.

In one embodiment, the exhaust mechanism is connected to the second flow passage and is connected to the small exhaust flow passage having the first exhaust amount and the second flow passage, and has the second exhaust amount larger than the first exhaust amount. A large exhaust flow path and a first exhaust valve that is provided in the large exhaust flow path and controls exhaust timing may be provided. With such a configuration, the exhaust timing can be controlled for each exhaust flow path, so that the pressure can be finely adjusted in the flow path between the control valve and the orifice.

In one embodiment, the exhaust mechanism may further include a second exhaust valve that is provided in the small exhaust passage and controls the exhaust timing. With such a configuration, the exhaust timing can be controlled for each exhaust flow path, so that the pressure can be more finely adjusted in the flow path between the control valve and the orifice.

In one embodiment, the exhaust mechanism may be connected to the orifice side in the flow path between the control valve and the orifice. With this configuration, it is possible to reduce an error in pressure adjustment as compared with the case where the exhaust mechanism is connected to the control valve side in the flow path between the control valve and the orifice.

In one embodiment, the gas supply system further includes a pressure detector that detects the pressure of the second gas in the flow passage of the second flow passage between the control valve and the orifice, and the pressure detector includes the control valve and The control valve, which is located on the orifice side in the flow path between the orifice and the orifice, may control the flow rate of the second gas based on the detection result of the pressure detector. With such a configuration, it is possible to reduce the error in flow rate adjustment as compared with the case where the pressure detector is located on the control valve side in the flow path between the control valve and the orifice.

In one embodiment, the gas supply system further comprises a temperature detector that detects the temperature of the second gas in the flow passage of the second flow passage between the control valve and the orifice, and the temperature detector includes the control valve and The control valve, which is located on the side of the orifice in the flow path between the orifice and the orifice, may control the flow rate of the second gas based on the detection result of the temperature detector. With this configuration, it is possible to reduce an error in flow rate adjustment as compared with the case where the temperature detector is located on the control valve side in the flow path between the control valve and the orifice.

In one embodiment, when supplying the second gas at the target flow rate to the first flow path at the target supply timing, the controller operates the exhaust mechanism while closing the opening/closing valve for a predetermined period until reaching the target supply timing. In this state, the control valve may be controlled to flow the second gas at the target flow rate, and the opening/closing valve may be opened at the target supply timing. With this configuration, it is possible to omit the time from when the opening/closing valve is opened to when the flow path between the control valve and the orifice is filled with the gas having the predetermined target pressure, so that the response is excellent. ..

In one embodiment, the gas supply system further includes a control unit that acquires a control value of the control valve, the control valve extending according to the valve body, the valve seat, and the control voltage, and the valve body and the valve seat. And a piezoelectric element that opens and closes the control valve by moving the valve closer to or away from the control valve, and the control unit may determine whether the opening/closing valve is open or closed based on the control voltage of the piezoelectric element. Although the gas supply operation can be confirmed by the control pressure value, it is difficult to determine the normal operation of the gas supply when a constant flow rate output is output. A method of determining the opening/closing of the open/close valve by providing a magnetic proximity sensor or the like on the actuator of the open/close valve may be considered, but the number of parts increases and the configuration becomes complicated. In this gas supply system, the piezoelectric element of the control valve operates so as to follow the opening/closing of the opening/closing valve. Therefore, the opening/closing of the valve can be easily determined by using the control voltage of the piezoelectric element of the control valve.

In one embodiment, the control unit may compare the obtained control voltage with a predetermined reference value of the control voltage and output an alarm according to the comparison result. With this configuration, an alarm can be output when the on-off valve is not operating in a predetermined manner.

A substrate processing system according to another aspect of the present invention includes the gas supply system described above, and can process a substrate using the gas supply system described above.

A gas supply method according to another aspect of the present invention connects a first flow path that connects a first gas source of a first gas and a chamber, and a second gas source of a second gas and a first flow path. A second flow path, a control valve provided in the second flow path for controlling the flow rate of the second gas to a predetermined amount, an orifice provided downstream of the control valve at the end of the second flow path, An opening/closing valve that is provided at a connection point between the first flow path and the end of the second flow path and controls the supply timing of the second gas that is supplied from the outlet of the orifice to the first flow path; A gas supply system including an exhaust mechanism that is connected to a flow path between a valve and an orifice and that exhausts a second gas, and a controller that operates a control valve, an opening/closing valve, and an exhaust mechanism is used. A gas supply method for supplying gas to a chamber, comprising: a preparatory step of controlling a control valve to circulate a second gas at a target flow rate while operating an exhaust mechanism while closing an opening/closing valve. A supply step of opening the on-off valve and supplying the second gas at the target flow rate to the first flow path at the target supply timing during continuation.

According to the gas supply method according to another aspect of the present invention, the same effects as those of the gas supply system described above can be obtained.

According to various aspects and embodiments of the present invention, an improved gas supply system for controlling a plurality of gases to perform a process can be provided.

It is a schematic diagram of the gas supply system which concerns on 1st Embodiment. It is sectional drawing which shows a switching valve roughly. It is a figure which shows the lower part structure of an on-off valve roughly. It is sectional drawing which shows the substrate processing system which concerns on 1st Embodiment roughly. It is a figure which shows the opening/closing timing of the secondary valve for 1st gas, and the opening/closing valve for 2nd gas. It is a figure which shows the flow volume of the 2nd gas which passes through the control valve, opening-closing valve, and exhaust valve for 2nd gas. It is a schematic diagram of the gas supply system which concerns on 2nd Embodiment. It is a figure which shows the flow volume of the 2nd gas which passes through the control valve, opening-closing valve, and exhaust valve for 2nd gas. It is a schematic diagram of the gas supply system which concerns on 3rd Embodiment. It is a figure which shows an example of the opening/closing timing of a some on-off valve. It is a figure which shows the other example of the opening/closing timing of a some on-off valve. It is a figure explaining the input to the control circuit corresponding to a recipe and a recipe. It is a figure explaining an example of opening and closing control of the valve to input. It is a figure explaining the other example of opening/closing control of the valve with respect to input. It is a figure explaining the other example of the opening/closing control of the valve with respect to an input. It is a schematic diagram of the gas supply system which concerns on 4th Embodiment. It is a figure which shows an example of a structure of a control valve. It is a figure explaining opening and closing confirmation of an on-off valve. It is a system schematic diagram when evaluating the influence which the detection position of a pressure detector gives to flow control. It is an evaluation result evaluated in the system configuration of FIG. It is a system schematic diagram when evaluating the influence which the detection position of a pressure detector gives to flow control. It is an evaluation result evaluated in the system configuration of FIG. It is a system schematic diagram when evaluating the influence which the detection position of a temperature detector gives to flow control. 23 is an evaluation result evaluated in the system configuration of FIG. 23. It is the result of converting the graph of FIG. 24 with the data of 25° C. of FIG. It is a schematic diagram which shows the component which evaluated the influence which it has on flow control. It is an evaluation result of each component shown in FIG. It is a schematic diagram of the conventional gas supply system. It is a schematic diagram of the conventional gas supply system.

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

[First Embodiment]
FIG. 1 is a schematic diagram of a gas supply system 1 according to the first embodiment. A gas supply system 1 shown in FIG. 1 is a system that supplies gas to a chamber 12 of a substrate processing apparatus. The gas supply system 1 includes a first flow path L1 and a second flow path L2. The first flow path L1 connects the first gas source GS1 of the first gas and the chamber 12. The second flow path connects the second gas source GS2 of the second gas and the first flow path L1. The second flow path L2 joins the first flow path L1 at the connection point PP1. The first flow path L1 and the second flow path L2 are formed of, for example, pipes. The first gas may be supplied to the chamber 12 at a higher flow rate than the second gas. The first gas and the second gas are optional. The first gas may be, for example, a carrier gas. The carrier gas is, for example, Ar gas, N ₂ gas or the like.

The pressure type flow control device FC1 may be arranged on the downstream side of the first gas source GS1 in the first flow path L1 and on the upstream side of the connection point with the second flow path L2. A primary valve (not shown) is provided on the upstream side of the pressure type flow control device FC1, and a secondary valve (not shown) is provided on the downstream side of the pressure type flow control device FC1. The pressure type flow control device FC1 has a control valve, a pressure detector, a temperature detector, an orifice, and the like. The control valve is provided downstream of the primary valve. The orifice is provided downstream of the control valve and upstream of the secondary valve. In addition, the pressure detector and the temperature detector are configured to measure the pressure and temperature in the flow path between the control valve and the orifice. The pressure type flow control device FC1 adjusts the pressure of the flow passage upstream of the orifice by controlling the control valve according to the pressure and temperature measured by the pressure detector and the temperature detector. When a so-called critical expansion condition of P ₁ /P ₂ ≧about 2 is maintained between the upstream pressure P ₁ and the downstream pressure P ₂ of the orifice, the gas flow rate Q flowing through the orifice is Q=KP. ₁ (where K is a constant), and when the critical expansion condition is not satisfied, the gas flow rate Q flowing through the orifice is Q=KP ₂ ^m (P ₁ −P ₂ ) ⁿ (where K, m, n is a constant). Therefore, the gas flow rate Q can be controlled with high accuracy by controlling the upstream pressure P ₁ , and even if the pressure of the upstream gas of the control valve changes significantly, the control flow rate value hardly changes. It can exhibit excellent characteristics. The flow rate of the first gas of the first gas source GS1 is adjusted by the pressure-type flow rate control device FC1, passes through the connection point PP1 with the second flow path L2, and is supplied to the chamber 12.

A control valve VL1, an orifice OL1, and an opening/closing valve VL2 are sequentially arranged on the downstream side of the second gas source GS2 in the second flow path L2.

The control valve VL1 is provided in the second flow path L2 and controls the flow rate of the second gas to a predetermined amount. The control valve VL1 has the same function as the control valve included in the pressure type flow rate control device FC1. The pressure and temperature of the flow path between the control valve VL1 and the orifice OL1 can be detected by the pressure detector PM and the temperature detector TM.

The pressure detector PM detects the pressure of the second gas in the flow passage between the control valve VL1 and the orifice OL1 in the second flow passage L2. The pressure detector PM may be located on the orifice OL1 side in the flow path between the control valve VL1 and the orifice OL1. That is, the length of the flow path between the pressure detector PM and the orifice OL1 may be shorter than the length of the flow path between the control valve VL1 and the pressure detector PM. Since the pressure detector PM is located on the orifice OL1 side in the flow path between the control valve VL1 and the orifice OL1, it is possible to reduce an error in flow rate adjustment as compared with the case where the pressure detector PM is located on the control valve side.

The temperature detector TM detects the temperature of the second gas in the flow passage between the control valve VL1 and the orifice OL1 in the second flow passage L2. The temperature detector TM may be located on the orifice OL1 side in the flow path between the control valve VL1 and the orifice OL1. That is, the length of the flow path between the temperature detector TM and the orifice OL1 may be shorter than the length of the flow path between the control valve VL1 and the temperature detector TM. Since the temperature detector TM is located on the orifice OL1 side in the flow path between the control valve VL1 and the orifice OL1, it is possible to reduce an error in flow rate adjustment as compared with the case where the temperature detector TM is located on the control valve side.

The control valve VL1 controls the flow rate of the second gas based on the detection results of the pressure detector PM and the temperature detector TM. As a more specific example, the control circuit C2 determines the operation of the control valve VL1. The control circuit C2 inputs the pressure and temperature detected by the pressure detector PM and the temperature detector TM, and performs temperature correction of the detected pressure and flow rate calculation. Then, the control circuit C2 compares the set target flow rate with the calculated flow rate, and determines the operation of the control valve VL1 so that the difference becomes small. A primary valve may be provided between the second gas source GS2 and the control valve VL1.

The orifice OL1 is provided downstream of the control valve VL1 and at the terminal end L21 of the second flow path L2. The orifice OL1 has the same function as the orifice provided in the pressure type flow rate control device FC1. The opening/closing valve VL2 is provided at the connection point PP1 between the first flow path L1 and the terminal end L21 of the second flow path L2, and controls the supply timing of the second gas supplied from the outlet of the orifice OL1 to the first flow path L1. To do. The opening/closing valve VL2 has a function of controlling the supply timing of the second gas while allowing the first gas to pass through. Details of the configuration of the opening/closing valve VL2 will be described later. The flow rate of the second gas of the second gas source GS2 is adjusted by the control valve VL1 and the orifice OL1, and is supplied to the first flow path L1 by the opening operation of the opening/closing valve VL2 at the connection point PP1 with the first flow path L1. It is supplied to the chamber 12 through the first flow path L1.

The gas supply system 1 includes an exhaust mechanism E for exhausting the second gas, which is connected to a flow passage between the control valve VL1 and the orifice OL1 in the second flow passage L2. The exhaust mechanism E is connected to the second flow path L2 via the exhaust flow path EL. The exhaust flow path EL is connected to the connection point PP2 between the control valve VL1 and the orifice OL1 in the second flow path L2. The exhaust mechanism E may be connected to the orifice OL1 side in the flow path between the control valve VL1 and the orifice OL1. That is, the length of the flow path between the connection point PP2 and the orifice OL1 may be shorter than the length of the flow path between the control valve VL1 and the connection point PP2. By connecting the exhaust mechanism E to the orifice OL1 side in the flow path between the control valve VL1 and the orifice OL1, it is possible to reduce the pressure adjustment error as compared with the case where the exhaust mechanism E is connected to the control valve VL1 side. it can.

The exhaust mechanism E may include an orifice OL2 and an exhaust valve VL3 (an example of a second exhaust valve). The orifice OL2 has the same function as the orifice provided in the pressure type flow rate control device FC1. The exhaust passage EL provided with the orifice OL2 is also referred to as a small exhaust passage. The exhaust passage EL is connected to an exhaust device 51 that exhausts the chamber 12. The exhaust passage EL may be connected to another exhaust device. The exhaust valve VL3 is provided in the exhaust passage EL and can control the exhaust timing. When the exhaust valve VL3 is opened, of the second gas existing in the flow path between the control valve VL1 and the orifice OL1, the second gas whose flow rate is controlled by the orifice OL2 is exhausted from the exhaust flow path EL.

The gas supply system 1 includes a control valve VL1, an opening/closing valve VL2, and a controller C1 that operates the exhaust mechanism E. The controller C1 is a computer including a processor, a storage unit, an input device, a display device, and the like. The controller C1 inputs the recipe stored in the storage unit and outputs a signal to the control circuit C2 that operates the control valve VL1. Further, the controller C1 inputs the recipe stored in the storage unit and controls the opening/closing operation of the opening/closing valve VL2. The controller C1 also inputs the recipe stored in the storage unit and controls the exhaust mechanism E. For example, the controller C1 may operate the exhaust valve VL3 via the control circuit C2.

The orifice OL1 and the opening/closing valve VL2 may be arranged on the downstream side of the inlet block 55 provided in the chamber 12. For example, the inlet block 55 is arranged on the downstream side of the pressure type flow rate control device FC1 in the first flow path L1 and on the upstream side of the connection point PP1 with the second flow path L2. Similarly, the inlet block 55 is arranged between the control valve VL1 and the orifice OL1. The inlet block 55 has a channel formed therein, and connects a pipe on the upstream side of the inlet block 55 and a pipe or the chamber 12 on the downstream side of the inlet block 55. The inlet block 55 is separated when the chamber 12 is opened to the atmosphere, and divides the connected pipe or separates the chamber 12 and the pipe. The downstream side of the inlet block 55 (the chamber 12 side) may be exhausted to the atmosphere or below. Further, the inlet block 55 of the first flow path may be the same member as the inlet block 55 of the second flow path, or may be a different member. By locating the orifice OL1 and the opening/closing valve VL2 on the downstream side of the inlet block 55, that is, on the chamber 12 side of the inlet block 55, the gas at a position closer to the chamber 12 can be compared with the case of being positioned on the upstream side of the inlet block 55. Control can be performed. Therefore, the responsiveness of the gas supplied to the chamber 12 can be improved.

The control valve VL1 and the control circuit C2 provided on the second gas source GS2 side with the inlet block 55 as a reference may be unitized (unit U1 in the figure). The orifice OL1 and the opening/closing valve VL2 provided on the chamber 12 side with respect to the inlet block 55 may be unitized (unit U2 in the drawing). Unitization is to be integrated as one component. The unit U2 may include the pressure detector PM and the temperature detector TM. Further, the unit U2 may include a part of an exhaust flow path described later.

Next, the details of the configuration of the opening/closing valve VL2 will be described. FIG. 2 is a sectional view schematically showing the opening/closing valve VL2. The opening/closing valve VL2 is arranged on the first flow path L1. As shown in FIG. 2, the opening/closing valve VL2 includes a lower body portion 71 and an upper body portion 72. A sealing member 74 exhibiting a valve function is arranged between the lower body portion 71 and the upper body portion 72. The lower main body 71 defines a flow path for allowing gas to flow therein. The upper main body portion 72 includes components that operate the sealing member 74. The sealing member 74 may be made of a flexible material. The sealing member 74 may be, for example, an elastic member, a diaphragm, a bellows, or the like.

The lower body portion 71 defines a flow passage which is a part of the first flow passage L1 therein. As a specific example, the lower body 71 has an inlet 71a and an outlet 71b, and an internal flow passage 71c extending from the inlet 71a to the outlet 71b. The lower body 71 has a terminal end L21 of the second flow path L2 therein. That is, the orifice OL1 provided at the terminal end L21 is housed inside the lower body portion 71. Inside the lower body 71, the first flow path L1 and the second flow path L2 join together. The opening/closing valve VL2 controls the timing at which the second gas joins the first flow path by opening/closing the terminal L21 of the second flow path L2 with the sealing member 74.

As a specific example, an orifice support portion 71d for supporting the orifice OL1 is formed in the internal flow passage 71c. The orifice support portion 71d projects from the inner wall of the internal flow passage 71c toward the upper body portion 72 side (sealing member 74 side) of the internal flow passage 71c. The orifice support portion 71d has an inlet 71e and an outlet 71f, and an internal flow passage 71g extending from the inlet 71e to the outlet 71f. The internal flow path 71g constitutes a part of the second flow path L2. An orifice OL1 is provided at the outlet 71f of the orifice support portion 71d, which is the terminal end L21 of the second flow path L2. Around the orifice OL1, there is provided a seal portion 75 protruding toward the upper body portion 72 side (sealing member 74 side) from the orifice OL1.

The upper main body 72 has components that control the distance between the sealing member 74 and the orifice OL1. As a specific example, the upper main body portion 72 has a cylinder 76, a biasing member 78, and a drive portion 81.

The cylinder 76 fixedly supports the sealing member 74 and is housed inside the upper main body 72. For example, the cylinder 76 fixes the sealing member 74 to the lower end thereof. The cylinder 76 has a protruding portion 76a whose diameter is expanded outward. The cylinder 76 has a flow path 76b inside thereof. A seal member 79 is provided between the side surface of the protruding portion 76a and the inner wall of the upper body portion 72, and between the side surface of the cylinder 76 below the protruding portion 76a and the inner wall of the upper body portion 72. .. A space 82 is defined by the inner wall of the upper main body 72, the side wall of the cylinder 76, the lower surface of the protrusion 76 a, and the seal member 79. The flow path 76b of the cylinder 76 communicates with the space 82.

The biasing member 78 elastically biases the cylinder 76 in the direction in which the sealing member 74 is pressed against the orifice OL1. For example, the cylinder 76 is urged toward the lower body 71 side (orifice OL1 side). More specifically, the biasing member 78 applies a biasing force downward to the upper surface of the protruding portion 76a of the cylinder 76. The biasing member 78 presses the sealing member 74 against the orifice OL1 so as to seal the outlet 73 of the orifice OL1. In this way, the second flow path is closed by the action of the biasing member 78 (close control). The biasing member 78 is made of, for example, an elastic body. As a specific example, the biasing member 78 is a spring.

The drive unit 81 moves the cylinder 76 in the direction opposite to the pressing direction. The drive unit 81 supplies air to the flow path 76b of the cylinder 76 to fill the space 82 with air. When the pressure of the air filled in the space 82 becomes larger than the urging force of the urging member 78, the cylinder 76 moves up together with the sealing member 74. That is, the sealing member 74 is separated from the orifice OL1 by the drive unit 81. In this way, the second flow path is opened by the drive unit 81 (open control).

The internal flow path 71c of the lower body 71 has a structure that is not blocked by the operation of the sealing member 74. That is, the first flow path L1 is not blocked by the operation of the sealing member 74, and is always in a communicating state. FIG. 3 is a diagram schematically showing a lower structure of the opening/closing valve VL2. As shown in FIG. 3, the internal flow path 71c is defined so as to surround the periphery of the orifice support portion 71d. The first gas passes to the side of the orifice support portion 71d when the sealing member 74 is pressed against the orifice OL1, and the first gas of the orifice support portion 71d when the sealing member 74 is separated from the orifice OL1. Passes sideways and above. In this way, the sealing member 74 realizes the opening and closing of the second flow path L2 without affecting the flow of the first flow path L1.

As described above, in the gas supply system 1, the orifice OL1 is provided downstream of the control valve VL1 and at the end L21 of the second flow path L2, and the opening/closing valve VL2 is provided at the end L21 of the first flow path L1 and the second flow path L2. Is provided at a connection point PP1 for connection with. That is, since the orifice OL1 and the opening/closing valve VL2 are arranged at the connection point PP1 between the first passage L1 and the terminal end L21 of the second passage L2, the passage from the orifice OL1 to the opening/closing valve VL2 should be minimized. You can Thus, when the opening/closing valve VL2 is opened, it is possible to prevent the gas remaining in the flow path from the orifice OL1 to the opening/closing valve VL2 from being supplied to the chamber in a state where the flow rate is not controlled.

Further, in the gas supply system 1, since the opening/closing valve VL2 is provided at the connection point PP1 between the first flow path L1 and the terminal end L21 of the second flow path L2, the flow path from the opening/closing valve VL2 to the connection point PP1. Can be minimized. As a result, even when the pressure of the gas flowing through the first flow passage L1 is higher than the pressure of the gas flowing through the second flow passage L2, the flow of the second gas between the opening/closing valve VL2 and the connection point PP1. It is possible to avoid taking time to fill the path.

Further, in the gas supply system 1, since the exhaust mechanism E for exhausting the second gas is connected to the flow passage between the control valve VL1 and the orifice OL1 in the second flow passage L2, for example, the opening/closing valve VL2. Is closed and the exhaust mechanism E is operated, the flow path between the control valve VL1 and the orifice OL1 can be filled with the gas having a predetermined target pressure while the supply to the chamber 12 is stopped. Therefore, it is possible to omit the time from when the opening/closing valve VL2 is opened to when the flow path between the control valve VL1 and the orifice OL1 is filled with the gas having the predetermined target pressure, and therefore the response is excellent.

Hereinafter, a plasma processing apparatus according to an embodiment will be described as a substrate processing apparatus (substrate processing system) including the gas supply system 1. FIG. 4 is a diagram schematically showing the plasma processing apparatus according to the embodiment. The plasma processing apparatus 10 shown in FIG. 4 is a capacitively coupled plasma processing apparatus, and is an apparatus used for plasma processing, for example, plasma etching.

The plasma processing apparatus 10 includes a chamber 12. The chamber 12 has a substantially cylindrical shape. The chamber 12 is made of, for example, aluminum, and its inner wall surface is anodized. This chamber 12 is grounded for safety. A ground conductor 12a is mounted on the upper end of the side wall of the chamber 12 so as to extend upward from the side wall. The ground conductor 12a has a substantially cylindrical shape. Further, a loading/unloading port 12g for a substrate (hereinafter referred to as “wafer W”) is provided on the side wall of the chamber 12, and the loading/unloading port 12g can be opened and closed by a gate valve 54.

A substantially cylindrical support portion 14 is provided on the bottom of the chamber 12. The support portion 14 is made of, for example, an insulating material. The support portion 14 extends in the chamber 12 in the vertical direction from the bottom portion of the chamber 12. A mounting table PD is provided in the chamber 12. The mounting table PD is supported by the support portion 14.

The mounting table PD holds the wafer W on its upper surface. The mounting table PD has a lower electrode LE and an electrostatic chuck ESC. The lower electrode LE includes a first plate 18a and a second plate 18b. The first plate 18a and the second plate 18b are made of a metal such as aluminum aluminum and have a substantially disc shape. The second plate 18b is provided on the first plate 18a and is electrically connected to the first plate 18a.

An electrostatic chuck ESC is provided on the second plate 18b. The electrostatic chuck ESC has a structure in which electrodes that are conductive films are arranged between a pair of insulating layers or insulating sheets. A DC power supply 22 is electrically connected to the electrodes of the electrostatic chuck ESC via a switch 23. The electrostatic chuck ESC attracts the wafer W by electrostatic force such as Coulomb force generated by the DC voltage from the DC power supply 22. Accordingly, the electrostatic chuck ESC can hold the wafer W.

A focus ring FR is arranged on the peripheral portion of the second plate 18b so as to surround the edge of the wafer W and the electrostatic chuck ESC. The focus ring FR is provided to improve the uniformity of plasma processing. The focus ring FR can be made of, for example, a material such as silicon, quartz, or SiC.

A coolant channel 24 is provided inside the second plate 18b. The coolant channel 24 constitutes a temperature control mechanism. A coolant is supplied to the coolant channel 24 from a chiller unit provided outside the chamber 12 through a pipe 26a. The coolant supplied to the coolant channel 24 is returned to the chiller unit via the pipe 26b. In this way, the coolant is supplied to the coolant channel 24 so as to circulate. By controlling the temperature of this coolant, the temperature of the wafer W supported by the electrostatic chuck ESC is controlled.

Further, the plasma processing apparatus 10 is provided with a gas supply line 28. The gas supply line 28 supplies the heat transfer gas from the heat transfer gas supply mechanism, for example, He gas, between the upper surface of the electrostatic chuck ESC and the back surface of the wafer W.

Further, the plasma processing apparatus 10 is provided with a heater HT which is a heating element. The heater HT is embedded in the second plate 18b, for example. A heater power supply HP is connected to the heater HT. By supplying electric power from the heater power supply HP to the heater HT, the temperature of the mounting table PD is adjusted, and the temperature of the wafer W mounted on the mounting table PD is adjusted. The heater HT may be built in the electrostatic chuck ESC.

The plasma processing apparatus 10 also includes an upper electrode 30. The upper electrode 30 is arranged above the mounting table PD so as to face the mounting table PD. The lower electrode LE and the upper electrode 30 are provided substantially parallel to each other. A processing space S for performing plasma processing on the wafer W is provided between the upper electrode 30 and the mounting table PD.

The upper electrode 30 is supported on the upper portion of the chamber 12 via an insulating shield member 32. In one embodiment, the upper electrode 30 may be configured such that the distance in the vertical direction from the upper surface of the mounting table PD, that is, the wafer mounting surface is variable. The upper electrode 30 may include a top plate 34 and a support 36. The top plate 34 faces the processing space S, and the top plate 34 is provided with a plurality of gas discharge holes 34 a. The top plate 34 may be made of silicon or silicon oxide. Alternatively, the top plate 34 can be formed by applying a ceramic coating to a conductive (for example, aluminum) base material.

The support 36 detachably supports the top plate 34 and may be made of a conductive material such as aluminum. The support 36 may have a water cooling structure. A gas diffusion space 36 a is provided inside the support 36. The merging pipe (first flow path L1) of the gas supply system 1 is connected to the gas diffusion chamber 36a.

The support 36 is formed with a plurality of communication holes 36b that connect the gas diffusion chamber 36a and a plurality of gas discharge holes 34a extending below the gas diffusion chamber 36a. The upper electrode 30 having such a configuration constitutes the shower head SH.

Further, in the plasma processing apparatus 10, the deposit shield 46 is detachably provided along the inner wall of the chamber 12. The deposit shield 46 is also provided on the outer periphery of the support portion 14. The deposit shield 46 prevents the by-product (depot) of plasma processing from adhering to the chamber 12, and can be formed by coating an aluminum material with ceramics such as Y ₂ O ₃ .

An exhaust plate 48 is provided on the bottom side of the chamber 12 and between the support 14 and the side wall of the chamber 12. The exhaust plate 48 can be configured by coating an aluminum material with a ceramic such as Y ₂ O ₃ , for example. A large number of through holes are formed in the exhaust plate 48. An exhaust port 12e is provided below the exhaust plate 48 and in the chamber 12. An exhaust device 50 and an exhaust device 51 are connected to the exhaust port 12e via an exhaust pipe 52. In one embodiment, the exhaust device 50 is a turbo molecular pump and the exhaust device 51 is a dry pump. The exhaust device 50 is provided upstream of the exhaust device 51 with respect to the chamber 12. The exhaust passage EL of the gas supply system 1 is connected to a pipe between the exhaust device 50 and the exhaust device 51. By connecting the exhaust passage EL between the exhaust device 50 and the exhaust device 51, the backflow of gas from the exhaust passage EL into the chamber 12 is suppressed.

The plasma processing apparatus 10 further includes a first high frequency power supply 62 and a second high frequency power supply 64. The first high frequency power supply 62 is a power supply that generates a first high frequency for plasma generation, and generates a high frequency of 27 to 100 MHz, for example, a high frequency of 40 MHz. The first high frequency power supply 62 is connected to the lower electrode LE via a matching unit 66. The matching device 66 has a circuit for matching the output impedance of the first high-frequency power supply 62 and the input impedance of the load side (lower electrode LE side).

The second high frequency power supply 64 is a power supply that generates a second high frequency for attracting ions to the wafer W, that is, a high frequency for bias, and has a frequency within the range of 400 kHz to 13.56 MHz, in one example, 3.2 MHz. Generate a second high frequency of The second high frequency power supply 64 is connected to the lower electrode LE via the matching unit 68. The matching device 68 has a circuit for matching the output impedance of the second high frequency power supply 64 and the input impedance of the load side (lower electrode LE side).

Further, in one embodiment, the controller C1 shown in FIG. 1 controls each unit of the plasma processing apparatus 10 for the plasma processing performed by the plasma processing apparatus 10.

In this plasma processing apparatus 10, the gas supplied into the chamber 12 can be excited to generate plasma. Then, the wafer W can be processed by the active species. Further, by the gas supply system 1, for example, while supplying the first gas at the first flow rate, the second gas can be intermittently and responsively supplied to the chamber 12 at the second flow rate smaller than the first flow rate. .. Therefore, it is possible to increase the throughput of the process in which different plasma processes are alternately performed on the wafer W.

Next, a gas supply method by the gas supply system 1 will be described. The gas supply method can be realized by operating the components by the controller C1. FIG. 5 is a diagram showing opening/closing timings of the secondary valve for the first gas and the opening/closing valve VL2 for the second gas. As shown in FIG. 5, the controller C1 opens the secondary valve for the first gas. Next, in the controller C1, the opening/closing valve VL2 repeats opening/closing with the secondary valve for the first gas being opened. As an example of such a process, the first gas is a carrier gas and the second gas is a processing gas necessary for plasma processing.

The gas supply system 1 controls the opening/closing of the control valve VL1 and the exhaust valve VL3 in accordance with the opening/closing control of the opening/closing valve VL2. Specifically, when supplying the second gas at the target flow rate to the first flow path L1 at the target supply timing, the controller C1 closes the opening/closing valve VL2 and closes the opening/closing valve VL2 for a predetermined period until the target supply timing is reached. With E in operation, the control valve VL1 is controlled to flow the second gas at the target flow rate, and the opening/closing valve is opened at the target supply timing.

FIG. 6 is a diagram showing the flow rate of the second gas passing through the control valve VL1 for the second gas, the opening/closing valve VL2, and the exhaust valve VL3. In FIG. 6, the steps of the processing process are expressed by using broken lines, and the case where the total number of steps of the processing process is 15 is shown. As the opening/closing valve VL2 performs the opening/closing operation described with reference to FIG. 5, the second gas intermittently flows through the opening/closing valve VL2, as shown in FIG. In FIG. 6, the controller C1 opens the opening/closing valve VL2 in steps 3, 5, 8 and 12 (an example of target supply timing). The controller C1 opens the control valve VL1 and the exhaust valve VL3 in a state where the open/close valve VL2 is closed in step 2 (an example of a predetermined period until reaching the target supply timing), which is a step immediately before step 3, and exhausts the exhaust gas. The mechanism E is operated (preparation step). That is, in step 2, the second gas that has passed through the control valve VL1 is not supplied to the first flow path L1 but is exhausted through the exhaust flow path EL. At this time, the pressure and flow rate of the gas in the second flow path are controlled to the set target values by the control valve VL1. The controller C1 can synchronize the control valve VL1 and the exhaust valve VL3 by an arbitrary method. For example, the controller C1 may control to open the exhaust valve VL3 of the small exhaust passage EL1 when the input flow rate to the control valve VL1 is larger than 0. The controller C1 may close the exhaust valve VL3 of the small exhaust passage EL1 when the input flow rate to the control valve VL1 is 0.

The controller C1 opens the opening/closing valve VL2 and supplies the second gas at the target flow rate to the first flow path at the target supply timing of step 3 during the preparation step (supply step). As described above, by closing the opening/closing valve VL2 and operating the exhaust mechanism E, the gas between the control valve VL1 and the orifice OL1 is supplied with a gas having a predetermined target pressure while the supply to the chamber 12 is stopped. Can be satisfied. Therefore, it is possible to omit the time from when the opening/closing valve VL2 is opened to when the flow path between the control valve VL1 and the orifice OL1 is filled with the gas having the predetermined target pressure, and therefore the response is excellent.

[Second Embodiment]
The gas supply system 1A according to the second embodiment is different from the gas supply system 1 according to the first embodiment in that an exhaust mechanism EA is provided instead of the exhaust mechanism E, and a gas supply method by the controller C1 is different. .. In the second embodiment, differences from the first embodiment will be mainly described, and redundant description will be omitted.

FIG. 7 is a schematic diagram of a gas supply system 1A according to the second embodiment. The exhaust mechanism EA has a small exhaust passage EL1 and a large exhaust passage EL2 as the exhaust passage EL. The small exhaust passage EL1 and the large exhaust passage EL2 are connected to the passage between the control valve VL1 and the orifice OL1 in the second passage. The small exhaust passage EL1 has a smaller exhaust amount than the large exhaust passage EL2. Specifically, the small exhaust flow path EL1 is provided with an orifice OL2 and controls the exhaust amount to the first exhaust amount. The small exhaust flow path EL1 may be provided with an exhaust valve VL3 (an example of a second exhaust valve) that controls the exhaust timing. The large exhaust flow path EL2 exhausts at a second exhaust amount that is larger than the first exhaust amount. The large exhaust passage EL2 is not provided with a device for controlling the flow rate. The large exhaust flow path EL2 may be provided with an exhaust valve VL4 (an example of a first exhaust valve) that controls the exhaust timing. The exhaust mechanism EA can be controlled by the controller C1 via the control circuit C2, similarly to the exhaust mechanism E according to the first embodiment. The other configurations of the gas supply system 1A are the same as those of the gas supply system 1. The gas supply system 1A can be applied to the plasma processing apparatus 10.

Next, a gas supply method by the gas supply system 1A will be described. The gas supply method can be realized by operating the components by the controller C1. The opening/closing timings of the secondary valve for the first gas and the opening/closing valve VL2 for the second gas are the same as those in FIG. The gas supply system 1A controls the opening/closing of the control valve VL1 and the exhaust valves VL3, VL4 in accordance with the opening/closing control of the opening/closing valve VL2. Specifically, when supplying the second gas of the target flow rate to the first flow path L1 at the target supply timing, the controller C1 closes the opening/closing valve VL2 and closes the opening/closing valve VL2 for a predetermined period until the target supply timing is reached. With E in operation, the control valve VL1 is controlled to flow the second gas at the target flow rate, and the opening/closing valve is opened at the target supply timing.

FIG. 8 is a diagram showing the flow rate of the second gas passing through the control valve VL1 for the second gas, the opening/closing valve VL2, and the exhaust valves VL3, VL4. It should be noted that only the flow rate relating to the control valve VL1 is shown as an input flow rate (IN) and an output flow rate (OUT) to the control valve VL1. In FIG. 8, the steps of the processing process are expressed using broken lines, and the case where the total number of steps of the processing process is 15 is shown. As the opening/closing valve VL2 performs the opening/closing operation described with reference to FIG. 5, the second gas intermittently flows through the opening/closing valve VL2 as shown in FIG. In FIG. 8, the controller C1 opens the opening/closing valve VL2 in steps 3, 5, 8 and 12 (an example of target supply timing). The controller C1 performs the preparation step and the supply step described in the gas supply method of the first embodiment.

Here, the controller C1 controls the exhaust mechanism E as follows. The controller C1 opens the exhaust valve VL3 of the small exhaust passage EL1 when the input flow rate to the control valve VL1 is larger than 0. The controller C1 closes the exhaust valve VL3 of the small exhaust passage EL1 when the input flow rate to the control valve VL1 is 0. The controller C1 controls the opening/closing of the exhaust valve VL4 of the large exhaust passage EL2 by using the relationship between the input flow rate and the output flow rate of the control valve VL1. As a specific example, the controller C1 opens the exhaust valve VL4 of the large exhaust flow path EL2 when the input flow rate becomes equal to or smaller than the output flow rate by a predetermined amount, and closes otherwise. In FIG. 8, in Steps 2 and 7, the input flow rate is not lower than the output flow rate by a predetermined amount, and in Steps 10 and 14, the input flow rate is lower than the output flow rate by a predetermined amount. As shown in FIG. 8, the controller C1 opens the exhaust valve VL4 of the large exhaust passage EL2 in steps 10 and 14 to increase the exhaust amount. In this way, since the exhaust timing can be controlled for each exhaust flow path, it is possible to finely adjust the pressure in the flow path between the control valve VL1 and the orifice OL1.

[Third Embodiment]
Compared with the gas supply system 1 according to the first embodiment, the gas supply system 1B according to the third embodiment further includes a configuration for merging the third gas into the first flow path L1, and the gas by the controller C1. The supply method is different. In the third embodiment, differences from the first embodiment will be mainly described, and redundant description will be omitted.

FIG. 9 is a schematic diagram of a gas supply system 1B according to the third embodiment. The gas supply system 1B includes a third flow path L3 that connects the third gas source GS3 of the third gas and the first flow path L1.

A control valve VL41, an orifice OL3, and an opening/closing valve VL5 are sequentially arranged on the downstream side of the third gas source GS3 in the third flow path L3. The control valve VL41 has the same configuration as the control valve VL1 and is controlled by a control circuit (not shown) having the same configuration as the control circuit C2. The orifice OL3 has the same configuration as the orifice OL1. The open/close valve VL5 is provided at the connection point PP3 between the first flow path L1 and the third flow path L3, and has the same configuration as the open/close valve VL2. The flow rate of the third gas of the third gas source GS3 is adjusted by the control valve VL41 and the orifice OL3, and the third gas is supplied to the first flow path L1 by the opening operation of the opening/closing valve VL5 at the connection point PP3 with the first flow path L1. It is supplied to the chamber 12 through the first flow path L1.

The gas supply system 1B includes an exhaust mechanism EB that exhausts the third gas, which is connected to the flow passage between the control valve VL41 and the orifice OL3 in the third flow passage L3. The exhaust mechanism EB is connected to the third flow path L3 via the exhaust flow path EL3. The exhaust passage EL3 is connected to a connection point PP4 between the control valve VL41 and the orifice OL3 in the third passage L3. The exhaust mechanism EB has the same configuration as the exhaust mechanism E. The exhaust passage EL3 is connected to the exhaust passage EL at a connection point PP5. The exhaust passage EL3 may be connected to another exhaust device.

The above-described constituent element that merges the third gas into the first flow path L1 can be controlled by the controller C1 described in the first embodiment. The orifice OL3 and the opening/closing valve VL5 may be arranged on the downstream side of the inlet block 55 provided in the chamber 12. The orifice OL3 and the opening/closing valve VL5 provided on the chamber 12 side with respect to the inlet block 55 may be unitized (unit U3 in the drawing). The unit U3 may include the pressure detector PM and the temperature detector TM. Further, the unit U3 may include a part of the exhaust passage EL3. The other configurations of the gas supply system 1B are the same as those of the gas supply system 1. The gas supply system 1B can be applied to the plasma processing apparatus 10.

Next, a gas supply method by the gas supply system 1B will be described. The gas supply method can be realized by operating the components by the controller C1. The opening/closing timing of the secondary valve for the first gas is arbitrary. That is, the first gas may or may not be introduced. FIG. 10 is a diagram showing an example of opening/closing timings of the opening/closing valves VL2 and VL5. As shown in FIG. 10, the controller C1 alternately opens and closes the opening/closing valve VL2 for the second gas and the opening/closing valve VL5 for the third gas. That is, the controller C1 periodically opens and closes the open/close valves VL2 and VL5 and shifts the open/close cycle. As an example of such a process, the first gas is a carrier gas, and the second gas and the third gas are processing gases necessary for plasma processing. In another example, the first gas is not introduced and the second gas and the third gas are process gases necessary for plasma processing. FIG. 11 is a diagram showing another example of opening/closing timings of the opening/closing valves VL2, VL5. As shown in FIG. 11, the controller C1 may open and close the opening/closing valve VL2 for the second gas and the opening/closing valve VL5 for the third gas in synchronization with each other.

Next, a specific example in which the controller C1 reads and executes the recipe of the processing process will be described. The recipe is stored in advance in the storage unit of the controller C1. FIG. 12 is a diagram illustrating a recipe and an input to the control circuit corresponding to the recipe. As shown in FIG. 12A, the recipe includes Ar gas (an example of the first gas), O ₂ gas (an example of the second gas), and C ₄ F ₆ in the processing process of steps 1 to 8. The flow rate of gas (an example of the third gas) is set in advance. In this recipe, supplied in steps 1 to 8 of Ar gas as a carrier gas, the _{O 2} gas and _C 4 _{F 6} gas supplied in Step 3 and Step 5 as an additive gas, the _C 4 _{F 6} gas as an additional gas Supply in step 8. When the controller C1 reads the recipe shown in FIG. 12A from the storage unit, the controller C1 controls the pressure type flow rate control device FC1 so that the processing process shown in FIG. , Outputs a signal to the control circuit of the control valve VL1.

The control process shown in FIG. 12B is modified to supply the additive gas at the same flow rate as the supply step in the step immediately before the additive gas supply step based on the recipe (in the figure). Shaded part). Specifically, the controller C1 changes the flow rate of O ₂ gas in the second step from 0 [sccm] to 6 [sccm], and changes the flow rate of C ₄ F ₆ gas in the second step from 0 [sccm] to 7 [sccm]. Change to 5 [sccm]. Further, the controller C1 changes the flow rate of O ₂ gas in the third step from 0 [sccm] to 6 [sccm], and changes the flow rate of C ₄ F ₆ gas in the third step from 0 [sccm] to 7.5 [sc]. sccm]. Further, the controller C1 changes the flow rate of the C ₄ F ₆ gas in the seventh step from 0 [sccm] to 5.5 [sccm].

The controller C1 and the control circuit control each valve based on the input to the control circuit corresponding to the recipe shown in FIG. Since the valve control method for the second gas and the third gas is the same, the method for controlling the second gas will be described below, and the method for controlling the third gas will be omitted. Further, only the typical steps of the method of controlling the second gas will be described. FIG. 13 is a diagram illustrating an example of opening/closing control of a valve with respect to an input. FIG. 13A shows the process of the controller C1. As shown in FIG. 13A, the controller C1 inputs a recipe that the second gas is supplied at a flow rate α [sccm] in step N. The controller C1 changes the input (target setting) to the control circuit corresponding to the recipe when the second gas is supplied at the flow rate α [sccm] in step N-1. Then, the controller C1 determines the open/closed state of the valve at each step. The controller C1 directly controls the opening/closing valve VL2, and indirectly controls the control valve VL1 and the exhaust valve VL3 via the control circuit of the control valve VL1.

In step N-2, the controller C1 sets the control valve VL1 to be closed, the opening/closing valve VL2 to be closed, and the opening/closing valve VL2 to be closed. In step N-1, the controller C1 sets the control valve VL1 to open, the open/close valve VL2 to close, and the exhaust valve VL3 to open. In step N, the controller C1 sets the control valve VL1 to open, the open/close valve VL2 to open, and the exhaust valve VL3 to open. In step N+1, the controller C1 sets the control valve VL1 closed, the opening/closing valve VL2 closed, and the exhaust valve VL3 closed.

Then, in each step, the controller C1 opens and closes the on-off valve VL2 and outputs a signal to the control circuit so as to operate as set. The signal to the control circuit includes the target flow rate (input), the open/close state of the control valve VL1 and the exhaust valve VL3. The control circuit controls opening/closing of the control valve VL1 and the exhaust valve VL3 according to the signal input from the controller C1.

FIG. 13B shows the processing of the control circuit which has input a signal. As shown in FIG. 13B, in step N-2, the control circuit closes the control valve VL1 and the exhaust valve VL3. The controller C1 closes the opening/closing valve VL2. In step N-1, the control circuit opens the control valve VL1 and the exhaust valve VL3. Further, the control circuit controls the control valve VL1 so that the output flow rate becomes the flow rate α [sccm] (self-control). Further, by opening the exhaust valve VL3, the exhaust flow rate is automatically controlled by the orifice (self-control). The controller C1 closes the opening/closing valve VL2. Thus, in step N-1, the second gas flows at the flow rate α [sccm] in the flow path between the control valve VL1 and the orifice OL1.

Then, in step N, the control circuit opens the control valve VL1 and the exhaust valve VL3. Further, the control circuit controls the control valve VL1 so that the output flow rate becomes the flow rate α [sccm] (self-control). Further, by opening the exhaust valve VL3, the exhaust flow rate is automatically controlled by the orifice (self-control). The controller C1 opens the opening/closing valve VL2. In this way, in step N, the second gas adjusted to the flow rate α [sccm] in step N-1 is supplied to the first flow path L1. In step N+1, the control circuit closes the control valve VL1 and the exhaust valve VL3. The controller C1 closes the opening/closing valve VL2. As a result, the supply of the second gas to the first flow path L1 is stopped. In this way, the controller C1 performs the preparation step and the supply step described in the gas supply method of the first embodiment.

FIG. 14 is a diagram illustrating another example of the valve opening/closing control with respect to the input. FIG. 14A shows the processing of the controller C1. As shown in FIG. 14A, the controller C1 inputs a recipe that the second gas is supplied at the flow rate α [sccm] in step N and the second gas is supplied at the flow rate β in step N+1. The controller C1 changes the input (target setting) to the control circuit corresponding to the recipe when the second gas is supplied at the flow rate α [sccm] in step N-1. Since the step immediately before the supply step, step N+1, is the supply step, step N, the flow rate set in step N is not changed. That is, when the supply steps are continuous, the preparation step is set only in the first supply step, and the subsequent processing is controlled without the preparation step. Other processes are the same as the contents described in FIG. 13, and the processes are executed as shown in FIG. 14B according to the setting contents shown in FIG.

FIG. 15 is a diagram illustrating another example of opening/closing control of a valve with respect to an input. FIG. 15A shows the process of the controller C1. As shown in FIG. 15A, the controller C1 inputs a recipe that the second gas is supplied at a flow rate α [sccm] in step N and the second gas is supplied at a flow rate β in step N+2. As the input (target setting) to the control circuit corresponding to the recipe, the controller C1 is supplied with the second gas at a flow rate α [sccm] in step N−1 and is supplied with the flow rate β in step N+1. And change. Other processes are the same as the contents described in FIG. 13, and the processes are executed as shown in FIG. 14B according to the setting contents shown in FIG.

As described above, the gas supply system 1B can merge a plurality of gases into the first flow path L1. Further, the gas supply system 1B performs the preparation step and the supply step described in the gas supply method of the first embodiment in each of the second flow path L2 and the third flow path L3, thereby supplying gas with excellent responsiveness. It can be performed.

[Fourth Embodiment]
The gas supply system 1C according to the fourth embodiment is different from the gas supply system 1 according to the first embodiment in that the orifice OL1 and the opening/closing valve VL2 are located upstream of the inlet block 55. In the fourth embodiment, differences from the first embodiment will be mainly described, and redundant description will be omitted.

FIG. 16 is a schematic diagram of a gas supply system 1C according to the fourth embodiment. As shown in FIG. 16, in the gas supply system 1C, the connection point PP1 between the first flow path L1 and the second flow path L2 is located upstream of the inlet block 55. The other configurations of the gas supply system 1C are the same as those of the gas supply system 1.

The control valve VL1, the control circuit C2, the orifice OL1 and the opening/closing valve VL2 provided on the second gas source GS2 side with the inlet block 55 as a reference may be unitized (unit U4 in the drawing). The unit U4 may include the pressure detector PM and the temperature detector TM. Further, the unit U4 may include a part of the exhaust passage EL. As described above, in the gas supply system 1C, the constituent elements located from the control valve VL1 to the opening/closing valve VL2 can be unitized, so that each constituent element can be easily handled.

Although various embodiments have been described above, various modifications can be configured without being limited to the above-described embodiments. For example, the embodiments may be combined. Although the substrate processing apparatus described above is a capacitively coupled plasma processing apparatus, the substrate processing apparatus may be any plasma processing apparatus such as an inductively coupled plasma processing apparatus or a plasma processing apparatus that uses surface waves such as microwaves. May be

Further, in the gas supply systems 1A and 1B, a unit including an orifice and an opening/closing valve may be located upstream of the inlet block 55.

Further, although the control valve VL1 described above operates based on the detection result of the pressure detector PM arranged on the upstream side of the opening/closing valve VL2, the present invention is not limited to this. For example, the detection result of the added pressure detector may be used. The additional pressure detector is arranged, for example, on the downstream side of the opening/closing valve VL2, and detects the pressure in the first flow path L1. The control circuit C2 calculates the difference between the calculated flow rate obtained from the measured pressure value of the pressure detector PM and the set flow rate under the condition that the pressure in the second flow path L2 is at least twice the pressure in the first flow path L1. The control valve VL1 is controlled so as to decrease. Further, under the condition that the pressure in the second flow path L2 is smaller than twice the pressure in the first flow path L1, the control circuit C2 measures the pressure value measured by the pressure detector PM and the pressure value measured by the additional pressure detector PM. The control valve VL1 is controlled so as to reduce the difference between the calculated flow rate obtained from the differential pressure between and the set flow rate. As described above, the control valve VL1 described above may operate by differential pressure control. Also, the additional pressure detector may be incorporated into the unit U2 of FIG. That is, the additional pressure detector may be unitized with the orifice OL1 and the opening/closing valve VL2. Alternatively, the additional pressure detector may be incorporated into unit U4 of FIG. That is, the additional pressure detector may be unitized with the control valve VL1, the control circuit C2, the orifice OL1, and the opening/closing valve VL2.

Further, in the above-described embodiment, the control valve VL1 described above can be used to confirm the opening/closing of the opening/closing valve VL2. FIG. 17 is a diagram showing an example of the configuration of the control valve VL1. As shown in FIG. 17, the control valve VL1 has a drive unit 122. The drive unit 122 has a control circuit 124. A flow rate difference ΔF between the output flow rate and the set flow rate is input to the control circuit 124 from the control circuit C2 described above.

The drive unit 122 also includes a piezoelectric element 126 (piezo element). The piezoelectric element 126 is configured to move a valve body 130, which will be described later, in the opening/closing operation of the control valve VL1. The piezoelectric element 126 expands according to an applied voltage (an example of a control voltage), and opens or closes the control valve VL1 by moving a valve body 130 and a valve seat 128d, which will be described later, toward or away from each other. For example, the control circuit 124 controls the applied voltage Vp, which is the voltage applied to the piezoelectric element 126, so that the flow rate difference ΔF becomes zero. The control circuit 124 is adapted to input a signal specifying the applied voltage Vp to the piezoelectric element to the control circuit C2. That is, the control circuit C2 functions as a control unit that acquires a signal (control value of the control valve VL1) that specifies the applied voltage Vp to the piezoelectric element.

The control valve VL1 further includes a main body 128, a valve body 130 (diaphragm), a disc spring 132, a pressing member 134, a base member 136, a sphere 138, and a support member 140. The main body 128 provides a flow path 128a, a flow path 128b, and a valve chamber 128c. The flow path 128a and the flow path 128b form a part of the second flow path L2 described above. The body 128 also provides a valve seat 128d.

The valve body 130 is biased by the disc spring 132 via the pressing member 134 against the valve seat 128d. When the voltage applied to the piezoelectric element 126 is zero, the valve body 130 is in contact with the valve seat 128d, and the control valve VL1 is closed.

One end (lower end in the figure) of the piezoelectric element 126 is supported by the base member 136. The piezoelectric element 126 is connected to the support member 140. The support member 140 is connected to the pressing member 134 at one end (lower end in the drawing) of the support member 140. When a voltage is applied to the piezoelectric element 126, the piezoelectric element 126 expands. When the piezoelectric element 126 expands, the support member 140 moves in the direction away from the valve seat 128d, and accordingly, the pressing member 134 also moves in the direction away from the valve seat 128d. As a result, the valve body 130 is separated from the valve seat 128d, and the control valve VL1 is opened. The opening degree of the control valve VL1, that is, the distance between the valve body 130 and the valve seat 128d is controlled by the voltage applied to the piezoelectric element 126.

Here, the control circuit C2 can determine whether the on-off valve VL2 is opened or closed based on the voltage applied to the piezoelectric element 126. FIG. 18 is a diagram for explaining confirmation of opening/closing of the opening/closing valve. 18A is a gas supply recipe, FIG. 18B is an opening/closing timing of the opening/closing valve VL2, FIG. 18C is a detection value of the pressure detector PM, and FIG. (D) Control voltage of the piezoelectric element of the control valve VL1. In the case of the recipe as shown in FIG. 18A, the “open timing” of the opening/closing valve VL2 is the same as the “gas ON” timing of the recipe, as shown in FIG. 18B. Then, as shown in (C) of FIG. 18, the detection value of the pressure detector PM becomes a constant value regardless of whether the on-off valve VL2 is opened or closed. Such a constant pressure condition is realized by opening/closing the control valve VL1, that is, by operating the piezoelectric element 126. Control voltage of the piezoelectric element 126 changes from the voltage value _{V P1} at time _{T P1} of off valve VL2 is opened to the voltage value _{V P2,} the voltage value from the voltage value _{V P2} at time _{T P2} of the opening and closing valve VL2 is closed Change to V _P1 . Similarly, the control voltage of the piezoelectric element 126 changes from the voltage value V _P1 to the voltage value V _P2 at time T _P3 when the on-off valve VL2 opens, and the voltage value V _P2 at time T _P4 when the on-off valve VL2 closes. Changes to a voltage value V _P1 . The control circuit C2 can determine whether the on-off valve VL2 is open or closed by determining the change in the control voltage of the piezoelectric element 126. Therefore, the opening/closing of the opening/closing valve VL2 can be easily determined without adding a sensor or the like.

The control circuit C2 may compare the acquired control voltage with a predetermined reference value of the control voltage and output an alarm according to the comparison result. The predetermined reference value of the control voltage is, for example, the control voltage of the piezoelectric element 126 that operates when it is created according to the recipe. The reference value of the measured control voltage is stored in advance in a storage unit that can be referred to by the control circuit C2. The control circuit C2 acquires the reference value by referring to the storage unit and compares it with the acquired control voltage. The comparison result is, for example, a difference between the acquired control voltage and a predetermined reference value of the control voltage. The control circuit C2 outputs an alarm, for example, when the difference is equal to or more than a predetermined threshold value. The control circuit C2 outputs an alarm signal to, for example, a display or a speaker. Thereby, an alarm can be output when the on-off valve is not operating in a predetermined manner.

[Example]
Hereinafter, Examples and Comparative Examples carried out by the present inventor will be described in order to explain the above effects, but the present invention is not limited to the following Examples.

(Verification of detection position of pressure detector PM)
It was verified whether or not the detection position of the pressure detector PM that detects the pressure in the flow path between the control valve and the orifice affects the flow rate control. First, it was confirmed whether or not the positional relationship between the pressure detector PM and the orifice affects the flow rate control. FIG. 19 is a system schematic diagram when the influence of the detection position of the pressure detector PM on the flow rate control is evaluated. As shown in (A) of FIG. 19, the evaluation system includes a flow rate reference device FC2, a control valve VL7, a pressure detector PM, an orifice OL5, and an opening/closing valve VL8. The flow rate reference device FC2 has the same configuration as the pressure type flow rate control device FC1. As an evaluation method, as shown in FIG. 19(B), the distance from the orifice OL5 to the pressure detector PM is set to the separation distance LL1, and the separation distance LL1 is changed in the range of 0 [m] to 3 [m]. The error between the flow rate on the outlet side of the orifice OL5 and the set value was evaluated. The results are shown in Fig. 20.

FIG. 20 shows the evaluation result evaluated in the system configuration of FIG. The horizontal axis is the flow rate setting value [%], and the vertical axis is the flow rate error [%]. The flow rate set value is the ratio of the maximum flow rate that the orifice OL5 can flow. Flow rate error is measured when the separation distance LL1 is 0 [m], when the separation distance LL1 is 1 [m], when the separation distance LL1 is 2 [m], and when the separation distance LL1 is 3 m, and the results are plotted. did. The broken line in the figure is the standard specification value of the orifice. As shown in FIG. 20, it was confirmed that the absolute value of the flow rate error increases as the separation distance LL1 increases. It is considered that this is because the accuracy is lowered by the pressure difference of the length of the pipe between the orifice OL5 and the pressure detector PM.

Next, it was confirmed whether or not the positional relationship between the pressure detector PM and the control valve affects the flow rate control. FIG. 21 is a system schematic diagram when the influence of the detection position of the pressure detector PM on the flow rate control is evaluated. As shown in FIG. 21A, the evaluation system includes a flow rate reference device FC2, a control valve VL7, a pressure detector PM, an orifice OL5, and an opening/closing valve VL8. The flow rate reference device FC2 has the same configuration as the pressure type flow rate control device FC1. As an evaluation method, as shown in FIG. 21(B), the distance from the pressure detector PM to the control valve VL7 is set as the separation distance LL2, and the separation distance LL2 is changed in the range of 0 [m] to 3 [m]. Then, the error between the flow rate on the outlet side of the orifice OL5 and the set value was evaluated. The results are shown in Fig. 22.

FIG. 22 shows evaluation results evaluated in the system configuration of FIG. The horizontal axis is the flow rate setting value [%], and the vertical axis is the flow rate error [%]. The flow rate set value is the ratio of the maximum flow rate that the orifice OL5 can flow. Regarding the case where the separation distance LL2 is 0 [m], the separation distance LL2 is 1 [m], the separation distance LL22 [m], and the distance between the pressure detector PM and the control valve VL7 is 3 [m]. Measured and plotted the results. The broken line in the figure is the standard specification value of the flow rate standard FC2. As shown in FIG. 22, it was confirmed that the flow rate error does not depend on the pipe length between the pressure detector PM and the control valve VL7. From the results of FIGS. 20 and 22, it has been confirmed that the pressure detector PM can perform the flow rate control more accurately when it is located on the orifice side in the flow path between the control valve and the orifice. It was also confirmed that the length of the pipe between the orifice OL5 and the pressure detector PM should be 1 [m] or less in order to reduce the flow path error to 0.1 [%] or less. ..

(Verification of detection position of temperature detector TM)
It was verified whether or not the detection position of the temperature detector TM that detects the temperature in the flow path between the control valve and the orifice affects the flow rate control. FIG. 23 is a system schematic diagram when the influence of the detection position of the pressure detector PM on the flow rate control is evaluated. As shown in (A) of FIG. 19, the evaluation system is arranged in the measurement chamber RO1 at room temperature (25° C.), and the flow rate reference device FC2, the control valve VL7, the pressure detector PM, the temperature detector TM, the orifice. It has an OL 5 and an opening/closing valve VL8. The flow rate reference device FC2 has the same configuration as the pressure type flow rate control device FC1. The temperature detector TM was arranged on the control valve VL1 side and used for controlling the flow rate of the control valve VL1. The orifice OL5 and the opening/closing valve VL8 are arranged in a constant temperature bath RO2 whose temperature can be controlled in the range of 25°C to 50°C. The temperature was changed in the thermostatic chamber RO2, and the relationship between the flow rate on the outlet side of the orifice OL5 and the set value was evaluated. The distance LL3 between the pressure detector PM and the orifice OL5 was set to 2 [m]. The results are shown in FIGS. 24 and 25.

FIG. 24 shows evaluation results evaluated in the system configuration of FIG. The horizontal axis represents the flow rate setting value [%], and the vertical axis represents the measured flow rate [sccm] on the outlet side of the orifice OL5. The flow rate set value is the ratio of the maximum flow rate that the orifice OL5 can flow. The flow rate on the outlet side of the orifice OL5 and the set value were plotted for each of the cases where the set temperature of the thermostat RO2 was 25°C, 30°C, 40°C, and 50°C. FIG. 25 is a result obtained by converting the graph of FIG. 24 using the 25° C. data of FIG. 24 as a reference. The horizontal axis is the flow rate setting value [%], and the vertical axis is the value based on the flow rate of 25%. As shown in FIG. 25, it was confirmed that the larger the difference between the temperature of the orifice OL5 and the temperature detected by the temperature detector TM (25° C.), the larger the absolute value of the flow rate error. Thus, it was confirmed that it is important to accurately measure the temperature of the orifice. From the results of FIGS. 24 and 25, it was confirmed that the temperature detector TM can perform the flow rate control more accurately if it is located on the orifice side in the flow path between the control valve and the orifice.

(Verification of influence of each component of semiconductor manufacturing system on flow control)
The influence of the components of the semiconductor manufacturing system including the gas supply system on the flow control was evaluated. FIG. 26 is a schematic diagram showing constituent elements that have been evaluated for their effects on flow rate control. The flow control device is omitted. The system shown in FIG. 26 includes a first gas source GS1, a second gas source GS2 and a chamber 12. The first gas source GS1 is connected to the chamber 12 via the first flow path L1. The second gas source GS2 is connected to the second flow path L2. The second flow path L2 joins the first flow path L1 at the connection point PP1.

The evaluation method was as follows. Ar gas was used as the first gas, and the gas was continuously supplied to the chamber 12 at 750 [sccm]. The second gas was O ₂ gas and was intermittently supplied to the chamber 12 at 5 [sccm]. Then, plasma was generated in the chamber 12 and the emission intensity of the plasma was measured. The measured emission intensity was standardized based on the maximum emission intensity. The time from when gas is supplied to the measured emission intensity from 0% to 90% (evaluation at start-up), and from the supply of gas to the measured emission intensity from 100% to 20% (standup (Evaluation at the time of falling) was measured to confirm the responsiveness.

The evaluation sites were as follows. Part A is a flow control device. As the flow rate control device, the embodiment having the orifice OL1 and the opening/closing valve VL2 and the pressure type flow rate control device FC3 of the gas supply system 1 shown in FIG. 29 were evaluated. Part B is the length (Add Line length) from the flow rate control device to the connection point PP1. The Add Line length is the embodiment having the orifice OL1 and the opening/closing valve VL2 (Add Line length is 0 [m]), and the Add Line length is 0.15 [m], 1.00 [m], 3.00. The comparative example of [m] was evaluated. The part C is the length (Main Line length) from the first gas source GS1 to the chamber 12, and the cases of 0.15 [m], 1.00 [m], and 3.00 [m] were evaluated. .. Site D is the upper electrode capacitance, and the cases of 100 [cc], 160 [cc], and 340 [cc] were evaluated. Site E is the number of GAS holes, and the cases of 53 and 105 were evaluated. The results are shown in Fig. 27.

FIG. 27 shows the evaluation result of each component shown in FIG. Portions A to C surrounded by broken lines are portions corresponding to the portions included in the gas supply system according to the embodiment. Regarding the site A, in the evaluation at the time of rising, it was confirmed that the example is superior in responsiveness to the comparative example. That is, it was confirmed that the embodiment having the orifice OL1 and the opening/closing valve VL2 is superior in responsiveness to the pressure type flow rate control device FC3 of the gas supply system 1 shown in FIG. Regarding the part B, in both the evaluation at the time of rising and the evaluation at the time of falling, the case where the Add Line length was 0 [m] had the best responsiveness. That is, it was confirmed that the example having the orifice OL1 and the opening/closing valve VL2 has excellent responsiveness. It was also confirmed that the site C and the site E had small site dependence of responsiveness. It was also confirmed that the smaller the upper electrode volume, the better the responsiveness of the part D.

Then, the degree of influence of each part was calculated. The degree of influence indicates the ratio of the degree of influence of each part to the degree of total influence. As shown in FIG. 27, it was confirmed that the site B among the sites A to E is the most influential site. That is, it has been confirmed that the configuration of the embodiment having the orifice OL1 and the opening/closing valve VL2 is very effective for improving the responsiveness because the parameter of the most influential part can be controlled.

Note that the above measurement is the result when Ar gas is supplied, that is, when carrier gas is present. For example, as in the gas supply system 1B shown in FIG. 9, it may not be necessary to supply carrier gas. .. In such a case, the dependence of the response on the Main Line length tends to increase. Therefore, when the recipe includes a step of using the carrier gas, the orifice OL1 and the opening/closing valve VL2 are arranged upstream of the inlet block 55, and when there is no step of using the carrier gas in the recipe, the orifice OL1 and the opening/closing valve VL2 are arranged. May be arranged on the downstream side of the inlet block 55. That is, the positions of the orifice OL1 and the opening/closing valve VL2 with respect to the inlet block 55 may be determined according to the recipe.

1, 1A, 1B, 1C... Gas supply system, 10... Plasma processing device (substrate processing device), 12... Chamber, 51... Exhaust device, C1... Controller, 55... Inlet block, U1... Unit, U2... Unit, 74 ... Sealing member, 76... Cylinder, 78... Energizing member, 81... Driving part, 126... Piezoelectric element, 128d... Valve seat, 130... Valve body, C2... Control circuit (control part), E, EA, EB... Exhaust mechanism, EL... Exhaust flow channel, EL1... Small exhaust flow channel, EL2... Large exhaust flow channel, GS1... First gas source, GS2... Second gas source, GS3... Third gas source, L1... First flow channel , L2... Second flow path, L3... Third flow path, PP1, PP2, PP3, PP4, PP5... Connection point, FC1, FC3... Pressure type flow rate control device, OL1, OL2, OL3, OL5... Orifice, VL2 VL5... Open/close valve, PM... Pressure detector, TM... Temperature detector, L21... Termination, PP2... Connection point, VL1, VL41, VL7... Control valve, VL3, VL4... Exhaust valve.

Claims (15)

A gas supply system for supplying gas to a chamber of a substrate processing apparatus,
A first flow path connecting a first gas source of a first gas and the chamber;
A second flow path connecting the second gas source of the second gas and the first flow path;
A control valve provided in the second flow path for controlling the flow rate of the second gas to a predetermined amount;
An orifice provided at the end of the second flow path downstream of the control valve;
An opening/closing valve that is provided at a connection point between the first flow path and the end of the second flow path, and that controls the supply timing of the second gas supplied from the outlet of the orifice to the first flow path,
An exhaust mechanism that is connected to a flow path of the second flow path between the control valve and the orifice and discharges the second gas;
A controller that operates the control valve, the opening/closing valve, and the exhaust mechanism;
Gas supply system equipped with. The gas according to claim 1, wherein the opening/closing valve has a sealing member that is pressed against the orifice so as to seal the outlet of the orifice during the closing control and is separated from the orifice during the opening control. Supply system. The opening/closing valve includes a cylinder that fixedly supports the sealing member, an urging member that elastically urges the cylinder in a direction in which the sealing member is pressed against the orifice, and a direction opposite to the pressing direction. The gas supply system according to claim 2, further comprising: a drive unit that moves the cylinder in a direction. The gas supply system according to any one of claims 1 to 3, wherein the orifice and the opening/closing valve are arranged downstream of an inlet block provided in the chamber. The gas supply system according to claim 1, wherein the orifice and the opening/closing valve are arranged upstream of an inlet block provided in the chamber. The exhaust mechanism is
A small exhaust flow path connected to the second flow path and having a first exhaust amount;
A large exhaust flow path that is connected to the second flow path and has a second exhaust amount that is larger than the first exhaust amount;
A first exhaust valve provided in the large exhaust flow path for controlling exhaust timing;
The gas supply system according to claim 1, further comprising: The gas supply system according to claim 6, wherein the exhaust mechanism further includes a second exhaust valve that is provided in the small exhaust passage and controls exhaust timing. The gas supply system according to any one of claims 1 to 7, wherein the exhaust mechanism is connected to the orifice side in a flow path between the control valve and the orifice. A pressure detector for detecting the pressure of the second gas in a flow passage of the second flow passage between the control valve and the orifice,
The pressure detector is located on the orifice side in the flow path between the control valve and the orifice,
The gas supply system according to claim 1, wherein the control valve controls the flow rate of the second gas based on the detection result of the pressure detector. A temperature detector for detecting the temperature of the second gas in a flow passage of the second flow passage between the control valve and the orifice,
The temperature detector is located on the orifice side in the flow path between the control valve and the orifice,
The gas supply system according to claim 1, wherein the control valve controls a flow rate of the second gas based on a detection result of the temperature detector. When the controller supplies the second gas at the target flow rate to the first flow path at the target supply timing, the controller operates the exhaust mechanism while closing the opening/closing valve for a predetermined period until reaching the target supply timing. 11. The control valve is controlled to flow the second gas at the target flow rate in this state, and the opening/closing valve is opened at the target supply timing. The gas supply system according to the item. Further comprising a control unit for acquiring the control value of the control valve,
The control valve includes a valve element, a valve seat, and a piezoelectric element that expands according to a control voltage and opens or closes the control valve by moving the valve element and the valve seat closer or apart from each other. ,
The control unit determines opening/closing of the opening/closing valve based on a control voltage of the piezoelectric element,
The gas supply system according to any one of claims 1 to 11. The gas supply system according to claim 12, wherein the control unit compares the acquired control voltage with a predetermined reference value of the control voltage, and outputs an alarm according to the comparison result. A substrate processing system comprising the gas supply system according to claim 1. A first flow path connecting the first gas source of the first gas and the chamber;
A second flow path connecting the second gas source of the second gas and the first flow path;
A control valve provided in the second flow path for controlling the flow rate of the second gas to a predetermined amount;
An orifice provided at the end of the second flow path downstream of the control valve;
An opening/closing valve that is provided at a connection point between the first flow path and the end of the second flow path, and that controls the supply timing of the second gas supplied from the outlet of the orifice to the first flow path,
An exhaust mechanism that is connected to a flow path of the second flow path between the control valve and the orifice and discharges the second gas;
A controller that operates the control valve, the opening/closing valve, and the exhaust mechanism;
A gas supply method for supplying gas to a chamber of a substrate processing apparatus using a gas supply system comprising:
A preparatory step of controlling the control valve to circulate the second gas at a target flow rate while operating the exhaust mechanism while closing the opening/closing valve;
A supply step of opening the on-off valve and supplying the second gas at the target flow rate to the first flow path when a target supply timing comes while continuing the preparation step,
A gas supply method comprising:

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