Pressure-type flow control device and vaporization supply device

Abstract

To provide a flow rate control device that can appropriately control a flow rate over a wide control range.SOLUTION: A pressure-type flow rate control device 20 includes: a control valve 22; a pressure sensor 24 provided on the downstream side of the control valve; a first throttle section 27S provided in a main flow path PS on the downstream side of the pressure sensor; an on-off valve 28 provided in a branch flow path PL that branches from the main flow path between the pressure sensor and the first throttle section and merges with the main flow path on the downstream side of the first throttle section; a second throttle section 27L provided in the branch flow path; a control mechanism 32; and a fluid detection mechanism 30 for detecting fluid flowing through the on-off valve 28. Flow rate control is performed by controlling the control valve 22 based on open / close state of the on-off valve 28 and output of the pressure sensor 24.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a pressure-type flow control device and a vaporization supply device including the same.

Background Art

[0002] In semiconductor manufacturing equipment, chemical plants, etc., it is required to supply raw material gases and etching gases to a process chamber at a desired flow rate. As a gas flow rate control device, a mass flow controller (thermal mass flow controller) and a pressure-type flow control device are known.

[0003] The pressure-type flow control device is widely used because it can control the mass flow rate of various fluids with high accuracy by a relatively simple configuration combining a control valve and a throttle portion (for example, an orifice plate or a critical nozzle). The pressure-type flow control device has excellent flow control characteristics such that stable flow control can be performed even when the supply pressure on the primary side fluctuates greatly.

[0004] Some pressure-type flow control devices adjust the flow rate by controlling the fluid pressure on the upstream side of the throttle portion (hereinafter sometimes referred to as the upstream pressure P1). The upstream pressure P1 is controlled by adjusting the opening degree of a control valve disposed in the flow path on the upstream side of the throttle portion.

[0005] As the control valve, for example, a piezo element-driven valve configured to open and close a diaphragm valve body by a piezo actuator is used. The piezo element-driven valve has high responsiveness, and by performing feedback control based on the upstream pressure P1, the gas flow rate on the downstream side of the throttle portion can be appropriately controlled.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

[0007] Patent Document 1 discloses a pressure-type flow control device in which a flow path with an orifice for high flow rates and a flow path with an orifice for low flow rates are connected in parallel downstream of a control valve. This pressure-type flow control device can change the control flow rate range by switching the opening and closing of a switching valve provided in the high flow rate flow path, and can accurately control the flow rate over a wide range of flow rates.

[0008] Furthermore, Patent Document 2 discloses a pressure-type flow control device configured to expand the flow control range using two orifices as described above, in which a limit switch is provided on the switching valve. By using a limit switch, the actual open / closed state can be detected more reliably, thereby enabling more accurate flow control.

[0009] However, the limit switch is designed to detect the position of the actuator's moving member. Therefore, even if the actuator has moved and is in the open position, if the diaphragm valve body is stuck to the valve seat, it may not be possible to detect that it is actually in the closed position, which can sometimes cause problems with flow control.

[0010] Furthermore, even if the limit switch can detect that the switching valve is closed, as mentioned above, it only checks the state of the actuator and does not monitor the actual state of the valve body. Therefore, it cannot detect gas leaks that occur when the switching valve is closed. For this reason, simply installing a limit switch can lead to a decrease in accuracy, especially when controlling flow rates in the low flow rate range.

[0011] Furthermore, Patent Document 3 discloses the detection of the valve opening / closing state of a fluid control valve using an optical sensor. However, even when using an optical sensor in this way, just like when using a limit switch, it only confirms the operation of the actuator and does not allow confirmation of the state of the valve body itself, so the same problems as described above can occur.

[0012] Furthermore, Patent Document 4 discloses a vaporization supply device that heats a liquid material introduced into a vaporizer and supplies the generated gas with controlled flow rate. Such a vaporization supply device requires flow rate control of a relatively high-temperature gas (for example, 150°C or higher).

[0013] When controlling the flow rate of high-temperature gases, the flow path, including the switching valve, is often heated to prevent gas reliquefaction. However, especially in high-temperature environments, limit switches and optical sensors may not be able to accurately detect the actual flow state of the switching valve, which can lead to a decrease in the accuracy of flow control. In particular, in modern semiconductor manufacturing processes (such as the ALD process) that repeatedly switch and supply various gases, as the service life of the equipment increases, wear on the valve body and valve seat due to use increases, making gas leaks in the closed state more likely than before.

[0014] The present invention was made to solve the above problems, and its main objective is to provide a pressure-type flow control device and vaporization supply device that can achieve a wide flow control range by switching between a high flow rate range and a low flow rate range, while also being able to more accurately detect the open / closed state of the switching valve, and that can stably supply gas with controlled flow rate even in a high-temperature environment. [Means for solving the problem]

[0015] A pressure-type flow control device according to an embodiment of the present invention comprises a control valve, a pressure sensor provided downstream of the control valve, a first throttling section provided in the main flow path downstream of the pressure sensor, an on-off valve provided in a branch flow path that branches off from the main flow path between the pressure sensor and the first throttling section and merges with the main flow path downstream of the first throttling section, a second throttling section provided in the branch flow path, the control valve, the pressure sensor, and a control mechanism connected to the on-off valve, and is configured to control the flow rate by controlling the control valve based on the open / closed state of the on-off valve and the output of the pressure sensor, and is equipped with a fluid detection mechanism for detecting the fluid flowing through the on-off valve.

[0016] In one embodiment, the fluid detection mechanism includes a flow sensor provided downstream of the on-off valve.

[0017] In one embodiment, the fluid detection mechanism includes a differential pressure sensor that detects the differential pressure between the upstream and downstream pressures of the second throttling portion.

[0018] In one embodiment, the fluid detection mechanism includes a temperature sensor provided downstream of the on / off valve.

[0019] In one embodiment, the temperature sensor includes a thermocouple.

[0020] In one embodiment, the fluid detection mechanism includes a vibration sensor provided downstream of the on / off valve.

[0021] The vaporization supply device according to an embodiment of the present invention includes a vaporizer and the above-described pressure type flow rate control device connected to the downstream side of the vaporizer.

[0022] In a certain embodiment, the above-described vaporization supply device further includes a supply pressure sensor that measures the fluid pressure between the vaporizer and the flow rate control device.

Advantages of the Invention

[0023] According to the pressure type flow rate control device and the vaporization supply device according to the embodiment of the present invention, it is possible to appropriately control the flow rate and supply the gas used in a semiconductor manufacturing apparatus or the like over a wide control flow rate range.

Brief Description of the Drawings

[0024] [Figure 1] It is a schematic diagram showing a gas supply system including a pressure type flow rate control device and a vaporization supply device according to an embodiment of the present invention. [Figure 2] It is a diagram for explaining the operation when performing flow rate control while changing the control flow rate range, and shows the operation of an on-off valve, the upstream pressure, and the flow rate. [Figure 3] It is a schematic diagram showing a gas supply system including a pressure type flow rate control device and a vaporization supply device according to another embodiment of the present invention. [Figure 4] It is a schematic diagram showing a gas supply system including a pressure type flow rate control device and a vaporization supply device according to still another embodiment of the present invention.

Modes for Carrying Out the Invention

[0025] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiments.

[0026] Figure 1 shows a gas supply system 100 incorporating a pressure-type flow control device 20 (hereinafter sometimes referred to as the flow control device 20) and a vaporization supply device 50 according to an embodiment of the present invention. The gas supply system 100 comprises a liquid material source 2, a vaporization supply device 50 connected to the liquid material source 2, and a process chamber 6 connected to the vaporization supply device 50 via a shut-off valve 4. The vaporization supply device 50 comprises a vaporizer 10 and a flow control device 20 provided downstream of the vaporizer 10.

[0027] The gas supply system 100 is configured to vaporize the liquid material L from the liquid material source 2 in the vaporizer 10, and to supply the resulting material gas G to the process chamber 6 with the flow rate controlled by the flow rate control device 20. In Figure 1, the liquid supply path is shown with a thick solid line, and the gas supply path is shown with a thick dashed line.

[0028] A vacuum pump 8 is connected to the process chamber 6, which can reduce the pressure inside the chamber and in the flow paths connected to the chamber. Although only one gas supply line is shown in Figure 1, it goes without saying that multiple gas supply lines may be connected to the process chamber 6 to supply various gases.

[0029] Examples of liquid materials L used include HCDS (Si2Cl6), or organometallic materials such as TEOS (tetraethyl orthosilicate), TMGa (trimethylgallium), and TMAl (trimethylaluminum). These materials are liquid at room temperature and can be vaporized by heating them to, for example, 150°C to 200°C. The generated material gas G is then used in the process chamber 6 to create a silicon nitride film (SiN). x It is used to form insulating films such as silicon oxide films (SiO2 films).

[0030] The material gas G needs to be supplied to the process chamber 6 while being kept at a relatively high temperature to prevent reliquefaction. The vaporization supply device 50 in this embodiment is configured to vaporize the supplied liquid material L and to control the flow rate, so by placing the vaporization supply device 50 near the process chamber 6, it is possible to reduce the area that needs to be kept at a high temperature. Although not shown, the vaporization supply device 50 is equipped with multiple heaters, which can independently heat the vaporizer 10 and the flow rate control device 20 to the desired temperature.

[0031] The vaporizer 10 is configured to generate a material gas G by heating a liquid material L, which has been pumped from a liquid material source 2, using a heater (not shown). The vaporizer 10 may include a preheating section, a vaporization section, and a liquid replenishment valve provided in the flow path between them. By preheating the liquid material L in the preheating section to a temperature that does not cause vaporization, vaporization in the vaporization section can be facilitated. This suppresses the decrease in liquid temperature due to the latent heat of vaporization, making it easier to maintain a high supply pressure P0 of the material gas G and stably supply the gas.

[0032] Furthermore, in the vaporization supply device 50 of this embodiment, the supply pressure P0 of the material gas G generated in the vaporizer 10 is measured by the supply pressure sensor 12. By measuring the supply pressure P0, it is possible to determine whether the amount of liquid material L in the vaporization chamber is sufficient. When the supply pressure P0 falls below a threshold, the liquid replenishment valve can be opened to replenish the liquid material, enabling stable gas generation in the vaporization section.

[0033] Furthermore, the vaporizer 10 may be equipped with a liquid detection unit (not shown) that can detect when a liquid material L exceeding a predetermined amount has been supplied to the vaporization section. By providing a liquid detection unit, it is possible to prevent oversupply of liquid material L to the vaporization section. The liquid detection unit is composed of, for example, a thermometer (platinum resistance thermometer, thermocouple, thermistor, etc.), a liquid level gauge, a load cell, etc., placed in the vaporization chamber.

[0034] The following describes the detailed configuration of the flow rate control device 20 for controlling the flow rate of the material gas G generated in the vaporizer 10.

[0035] As shown in Figure 1, the flow control device 20 of this embodiment is a pressure-type flow control device and comprises a control valve 22, a pressure sensor 24 provided downstream of the control valve 22, a first throttling section (small flow rate throttling section) 27S provided in the main flow path PS downstream of the pressure sensor 24, an on-off valve 28 provided in a branch flow path PL that branches off from the main flow path PS between the pressure sensor 24 and the first throttling section 27S and merges with the main flow path PS downstream of the first throttling section 27S, a second throttling section (large flow rate throttling section) 27L provided in the branch flow path PL, and a control mechanism (control circuit) 32 connected to the control valve 22, the pressure sensor 24, and the on-off valve 28.

[0036] The flow rate control device 20 is configured to control the flow rate of gas flowing downstream of the throttling sections 27S and 27L by controlling the opening degree of the control valve 22 based on the open / closed state of the on / off valve 28 and the output of the pressure sensor 24. The flow rate control device 20 may also be equipped with a temperature sensor (not shown) for measuring the temperature of the gas downstream of the control valve 22, and the gas flow rate can be controlled more accurately by additionally referring to the output of the temperature sensor when controlling the opening degree of the control valve 22.

[0037] As the control valve 22, for example, a piezoelectric-driven valve can be used. A piezoelectric-driven valve can adjust the amount of movement of the diaphragm valve body by controlling the voltage applied to the piezoelectric element, and its opening degree can be adjusted arbitrarily. As the pressure sensor 24, for example, a silicon single-crystal pressure sensor having a pressure-sensitive diaphragm equipped with strain gauges, or a capacitance manometer can be used. As the temperature sensor, for example, a thermocouple, thermistor, or platinum resistance thermometer can be used.

[0038] In this embodiment, the aperture sections 27S and 27L are constructed using orifice plates. The orifice diameter of the first aperture section 27S is set to, for example, 40 μm to 1500 μm, and the orifice diameter of the second aperture section 27L is set to, for example, 180 μm to 2200 μm. However, critical nozzles or sonic nozzles can also be used as aperture sections 27S and 27L.

[0039] Furthermore, in this embodiment, the on-off valve 28 is configured using an AOV (air-operated valve). A solenoid valve 29 that controls the supply of compressed air is connected to the on-off valve 28, and the on-off valve 28 can be opened and closed quickly by controlling the solenoid valve 29. However, it is not limited to this, and the on-off valve 28 may be configured as an on / off valve such as a solenoid valve or an electric valve.

[0040] The flow rate control device 20 is configured to control the flow rate of gas flowing downstream of the first throttling section 27S or the second throttling section 27L by adjusting the opening degree of the control valve 22 based on the output of the pressure sensor 24, etc. When the on-off valve 28 is closed, the gas flows only through the main flow path PS, so the flow rate control device 20 can supply gas at a low flow rate. When the on-off valve 28 is opened, the gas also flows through the branch flow path PL, so the flow rate control device 20 can supply gas at a higher flow rate.

[0041] More specifically, the flow rate control device 20 controls the flow rate by utilizing the principle that when the critical expansion condition P1 / P2 ≥ approximately 2 (where P1 is the upstream pressure, P2 is the downstream pressure, and approximately 2 is the case for nitrogen gas), the flow rate Q is determined by the upstream pressure P1 and not by the downstream pressure P2.

[0042] When the critical expansion condition is met, the flow rate Q is calculated from Q = K1·P1 (where K1 is a constant that depends on the opening area of ​​the throttling section, the type of fluid, and the fluid temperature). Furthermore, if a downstream pressure sensor (not shown) is provided, even if the critical expansion condition is not met, the flow rate Q can be calculated as Q = K2·P2 m (P1-P2) n(Here, K2 is a constant that depends on the opening area of ​​the throttling section, the type of fluid, and the fluid temperature, and m and n are indices derived from the actual flow rate.)

[0043] The flow rate control device 20 calculates the calculated flow rate using a flow rate calculation formula for high flow rates (specifically, a formula using constants corresponding to the sum of the opening areas of the first and second throttling sections as K1 or K2 above) when the on-off valve 28 is open. When the on-off valve 28 is closed, the device is configured to calculate the calculated flow rate using a flow rate calculation formula for low flow rates (specifically, a formula using constants corresponding to the opening area of ​​the first throttling section as K1 or K2 above). Therefore, in either case, flow rate control can be performed by controlling the upstream pressure P1.

[0044] To perform flow rate control, a set flow rate Qs is input to the control mechanism 32. Based on the opening and closing status of the on-off valve 28 and the output of the pressure sensor 24, the control mechanism 32 calculates a calculated flow rate Qc according to the above formula and performs feedback control of the control valve 22 so that this calculated flow rate Qc approaches the input set flow rate Qs. The calculated flow rate Qc may be displayed on an external monitor as a flow rate output value.

[0045] Furthermore, the flow control device 20 of this embodiment includes a fluid detection mechanism 30 for detecting the fluid flowing through the on-off valve 28 or the second throttling section 27L. In this embodiment, the fluid detection mechanism 30 is composed of a flow sensor 30a provided between the on-off valve 28 and the second throttling section 27L. As the flow sensor 30a, for example, a thermal mass flow meter that measures the flow rate based on the fluid temperature difference between two points in the flow path, or an ultrasonic flow meter that measures the flow rate from the propagation state of ultrasonic waves can be used.

[0046] By providing the flow sensor 30a in this manner, it is possible to detect the leak flow rate even when the on-off valve 28, which functions as a control range switching valve, is closed, if gas is actually flowing. Therefore, when the on-off valve 28 is closed and flow control is performed in a small flow rate range, the actual flow rate can be determined more accurately by adding the leak flow rate measured by the flow sensor 30a to the calculated flow rate (corresponding to the flow rate of gas flowing through the first throttling section 27S) which is determined based on the upstream pressure P1. This leak flow rate may increase as the service life of the device lengthens, but if the leak flow rate can be measured, the flow rate can be corrected each time, making it possible to provide a more reliable flow control device over a longer period of time.

[0047] Furthermore, even when opening the on-off valve 28 to control a large flow rate, the flow rate of gas flowing out through the second throttling section 27L can be detected. Therefore, even if an open signal is issued to the on-off valve 28 and the actuator is operating normally, if the valve body remains attached to the valve seat and the desired amount of gas is not flowing or not flowing at all, such malfunctions can be easily detected.

[0048] The flow rate control device 20 is basically configured to calculate the flow rate based on the magnitude of the upstream pressure P1. Therefore, in a conventional configuration, even when the expected gas flow is not formed due to a malfunction of the on-off valve 28, there is a risk of mistakenly determining that gas is flowing at a flow rate corresponding to the magnitude of the upstream pressure P1. In contrast, by providing a fluid detection mechanism 30 that detects the fluid flowing through the on-off valve 28, the above-mentioned misjudgment can be prevented, and the actual gas flow can be recognized.

[0049] Figure 2 illustrates the operation when flow rate control is performed while changing the control flow rate range. First, the control valve 22 and the on-off valve 28 are closed, and the flow rate is 0. At time t1, the control valve 22 is opened, and flow rate control is performed within the desired small flow rate range. Since the on-off valve 28 is closed, gas supply is assumed to be through the main flow path PS only. Flow rate control can be maintained at a constant upstream pressure P1 and, consequently, a constant flow rate Q, by feedback control of the control valve 22 based on the upstream pressure P1 measured by the pressure sensor 24.

[0050] Next, at time t2, the flow rate control is switched to the high flow rate range. At this time, the on-off valve 28 is opened instantaneously, and gas supply is started via the branch flow path PL as well. At this time, even with a lower upstream pressure P1, gas can be supplied at a higher flow rate. Of course, contrary to the illustrated configuration, the upstream pressure P1 may be controlled to be maintained at a higher value or the same value, in which case gas can be supplied at an even higher flow rate.

[0051] Furthermore, when controlling the flow rate of gas from the vaporizer 10, the pressure of the generated gas (supply pressure P0) must always be higher than the upstream pressure P1. While the flow rate control device 20 of this embodiment makes it possible to flow a larger flow rate of gas at the desired flow rate than conventional methods, on the other hand, the decrease in supply pressure P0 becomes more significant. For this reason, it is preferable that the vaporizer 10 is configured to have a sufficiently high gas generation capacity, and that the vaporization supply device 50 is configured to monitor the supply pressure P0 with the supply pressure sensor 12 and maintain it at a value higher than the upstream pressure P1.

[0052] Next, at time t3, the flow control is switched back to the low flow rate range. At this time, the on-off valve 28 is instantaneously closed, and gas supply is started only through the main flow path PS. The upstream pressure P1 is maintained at any pressure that can achieve the desired flow rate through feedback control of the control valve 22.

[0053] As described above, even when supplying gas by switching the control range between a high flow rate range and a low flow rate range, the fluid detection mechanism 30 is provided, so that in each case, it is possible to detect the discrepancy between the actual flow rate and the calculated flow rate caused by malfunctions of the on-off valve, etc. Therefore, more accurate and stable flow rate control can be performed over a long period of time.

[0054] Furthermore, the on-off valve 28 and the second throttling section 27L provided in the branch flow path PL may be provided in the form of a valve with a built-in throttling section (here, a valve with a built-in orifice). In a valve with a built-in throttling section, the second throttling section 27L is located near the on-off valve 28, and more specifically, the valve mechanism of the on-off valve 28 and the second throttling section 27L are provided integrally in close proximity to each other. Here, "provided integrally" broadly means a configuration in which the valve mechanism of the on-off valve 28 and the second throttling section 27L are provided together in close proximity at a common mounting position (typically a recess) of the flow path block, and does not mean that they are fixed to each other. Also, it does not exclude the existence of other optional members between the valve mechanism of the on-off valve 28 and the second throttling section 27L.

[0055] As described above, by providing the on-off valve 28 and the second throttling section 27L as a valve with a built-in throttling section, the flow path volume between the valve mechanism (valve seat and valve body) and the throttling section can be minimized. This reduces the amount of residual gas that flows out through the second throttling section 27L when transitioning from open to closed. It also suppresses the temporary drop in the upstream pressure P1 that may occur when transitioning from closed to open. Therefore, it is possible to suppress fluctuations in the flow output (hunting, undershoot, overshoot) that may occur when switching between flow control ranges of low and high flow rates. A flow control device with a valve with a built-in throttling section in a branched flow path is disclosed in Japanese Patent Application No. 2022-35107 by the present applicant, and for reference, all of the disclosures in Japanese Patent Application No. 2022-35107 are incorporated herein by reference.

[0056] As described above, when using a valve with a built-in throttle section, either the on-off valve 28 or the second throttle section 27L may be positioned on the upstream side. Also, unlike the embodiment shown in Figure 1, in other embodiments, the fluid detection mechanism 30 may be provided in the flow path downstream of the second throttle section 27L, as long as it is provided downstream of the on-off valve 28.

[0057] Figure 3 shows a gas supply system 100b equipped with a flow rate control device 20b of another embodiment. In this embodiment, unlike the embodiment shown in Figure 1, the fluid detection mechanism 30 is composed of a differential pressure sensor 30b that detects the differential pressure Pd between the upstream pressure and the downstream pressure of the second throttling section 27L. Hereafter, the same reference numerals are used for components as in Figure 1, and detailed descriptions are omitted.

[0058] It is assumed that the pressure difference between the upstream and downstream sides increases as the gas flow rate through the second throttling section 27L increases. Furthermore, in normal gas flow, if the Cv value (Coefficient of flow) of the throttling section 27L is known, the flow rate can also be determined from the pressure difference between the primary and secondary pressures. Therefore, by using the differential pressure sensor 30b, it is possible to detect the generation of gas flow and the gas flow rate in the branched flow path PL.

[0059] Figure 4 shows a gas supply system 100c equipped with a flow control device 20c of yet another embodiment. In this embodiment, unlike the embodiment shown in Figure 1, the fluid detection mechanism 30 is composed of a temperature sensor 30c provided downstream of the on-off valve 28 and the second throttling section 27L. The temperature sensor 30c may also be provided between the on-off valve 28 and the second throttling section 27L. Hereafter, components similar to those in Figure 1 will be given the same reference numerals and detailed descriptions will be omitted.

[0060] In this embodiment, a thermocouple is used as the temperature sensor 30c. However, it is not limited to a thermocouple; a thermistor or platinum resistor can also be used.

[0061] The gas flow in the branch channel PL can be detected by referring to the output of the temperature sensor 30c. In an environment where high-temperature gas is flowing from the vaporizer 10, the gas temperature in the branch channel PL will also be high when gas is actually flowing, whereas the temperature is likely to be lower when no gas is flowing or only a very small amount of gas is flowing. Therefore, the gas flow in the branch channel PL can also be detected by measuring the gas temperature.

[0062] Furthermore, especially when a thermocouple is used as the temperature sensor 30c, the state of the gas flow can be estimated by the magnitude of the fluctuation (variation) in its output. Experiments by the inventors have confirmed that the output of a thermocouple is less stable and more prone to fluctuation as the gas flow rate increases. For this reason, for example, when the fluctuation in output (the difference between the maximum and minimum output of the time-varying output) exceeds a threshold, it can be determined that a significant gas flow is occurring.

[0063] Although embodiments of the present invention have been described above, various modifications are possible. The fluid detection mechanism 30 may be composed of, for example, a vibration sensor provided downstream of the on-off valve 28. Vibrations may occur depending on the magnitude of the gas flow, and based on the output of the vibration sensor, it is possible to determine whether or not gas is actually flowing in the branch channel PL, and the flow rate thereof.

[0064] Furthermore, although the above describes an embodiment in which two flow paths are connected in parallel downstream of the control valve 22, the invention is not limited to this, and three or more flow paths may be connected in parallel. In this case as well, by providing a fluid detection mechanism in each of the flow paths other than the main flow path (multiple branch flow paths), or in the common path between them, it becomes possible to switch between multiple ranges, and to detect leak flow or valve closing due to malfunction at the on-off valve 28, thereby enabling more stable and accurate flow rate control.

[0065] Furthermore, although the above description mentions the use of a conventional piezoelectric element-driven valve as the control valve 22, when controlling the flow rate of high-temperature gas from the vaporizer 10, a piezoelectric element-driven valve may be used in which a rod-shaped heat dissipation spacer (extension) is placed below the piezoelectric actuator (between it and the diaphragm valve body) for high-temperature countermeasures. The heat dissipation spacer is formed of, for example, Invar material, and by moving it in conjunction with the piezoelectric actuator, it is possible to appropriately control the flow rate while preventing the piezoelectric element from exceeding its heat resistance temperature even when high-temperature gas flows through it.

[0066] Furthermore, in order to control the flow rate at a larger flow rate, a diaphragm valve equipped with multiple actuators may be used as the control valve 22. Such a valve is disclosed, for example, in Japanese Patent Application Publication No. 2021-32391 by the present applicant. This type of valve comprises an operating member for opening and closing the diaphragm valve body, a main actuator for moving the operating member a relatively large distance, and a sub-actuator for moving the operating member a relatively small distance. As the main actuator, an air-driven actuator (or an actuator operated by a driving fluid) is used to move the operating member up and down, and as the sub-actuator, a piezo actuator (or an actuator that can be extended by electrical drive) is used.

[0067] In a valve configured in this way, the main actuator can move the operating member and the diaphragm valve body significantly, while the sub-actuator positioned inside can finely adjust the displacement of the operating member. Therefore, by controlling both the operating pressure of the main actuator and the applied voltage of the sub-actuator in combination, it becomes possible to accurately control the flow rate over a wide range from small to large flow rates. The use of the main actuator enables the flow of large gas flow rates, and the use of the sub-actuator allows for highly responsive fine adjustments, so when used as a control valve 22, the upstream pressure P1 can be controlled to a desired value over a wide range with good responsiveness. [Industrial applicability]

[0068] The pressure-type flow control device and vaporization supply device according to embodiments of the present invention are appropriately used to control flow rates over a wide control range when incorporated into gas supply systems such as semiconductor manufacturing equipment. [Explanation of Symbols]

[0069] 2 Liquid material source 4. Shut-off valve 6 Process Chambers 8. Vacuum pump 10. Vaporizer 12. Supply pressure sensor 20 Pressure-type flow control device 22 Control valve 24 Pressure Sensors 27L Second aperture section 27S First aperture section 28. Shut-off valves 29 Solenoid valve 30 Fluid detection mechanism 30a Flow Sensor 30b Differential pressure sensor 30°C temperature sensor 100 Gas supply systems P0 Supply pressure P1 Upstream pressure PS main channel PL branch channel

Claims

1. Control valve and A pressure sensor provided downstream of the control valve, A first throttling section is provided in the main flow path downstream of the pressure sensor, A valve is provided in a branch channel that branches off from the main channel between the pressure sensor and the first throttling section and merges with the main channel downstream of the first throttling section, A second throttling section is provided in the aforementioned branching channel, The control valve, the pressure sensor, and the control mechanism connected to the on / off valve Equipped with, A pressure-type flow control device configured to control the flow rate by controlling the control valve based on the open / closed state of the on / off valve and the output of the pressure sensor, A pressure-type flow control device having a fluid detection mechanism for detecting the fluid flowing through the on-off valve and detecting the open / closed state of the on-off valve.

2. The pressure-type flow control device according to claim 1, wherein the fluid detection mechanism includes a flow sensor provided downstream of the on-off valve.

3. The pressure-type flow control device according to claim 1, wherein the fluid detection mechanism includes a differential pressure sensor that detects the differential pressure between the upstream pressure and the downstream pressure of the second throttling portion.

4. The pressure-type flow control device according to claim 1, wherein the fluid detection mechanism includes a temperature sensor provided downstream of the on / off valve.

5. The pressure-type flow control device according to claim 4, wherein the temperature sensor includes a thermocouple.

6. The pressure-type flow control device according to claim 1, wherein the fluid detection mechanism includes a vibration sensor provided downstream of the on / off valve.

7. Vaporizer and, A pressure-type flow control device according to any one of claims 1 to 6, connected to the downstream side of the vaporizer, A vaporization supply device equipped with the following features.

8. The vaporization supply device according to claim 7, further comprising a supply pressure sensor for measuring the fluid pressure between the vaporizer and the pressure-type flow control device.

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