Flow control device and vaporization supply device

Abstract

To provide a flow-rate controller capable of appropriately controlling flow rate over a broad control range, and a vaporization supply apparatus comprising the same.SOLUTION: A flow-rate controller 20 comprises a control valve 22, a low flow-rate reducer unit 27S provided on a flow passage downstream of the control valve, a built in-reducer unit valve 26 that is provided on the flow passage downstream of the control valve in parallel with the low flow-rate reducer unit, the built in-reducer unit valve 26 being provided integrally with a high flow-rate reducer unit 27L in a valve mechanism including a valve seat and a valve body and for opening / closing the flow passage, and an upstream pressure sensor 24 that measures a fluid pressure between the control valve, the low flow-rate reducer unit and the built in-reducer unit valve. The flow-rate controller is configured to control the flow rate by controlling opening / closing of the built in-reducer unit valve and regulating the opening degree of the control valve based on an output of the upstream pressure sensor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a flow rate control device and a vaporization supply device.

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 rate control device are known.

[0003] The pressure type flow rate control device is widely used because it can control the mass flow rate of various fluids with high precision 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 rate control device has excellent flow rate control characteristics that can perform stable flow rate control even when the supply pressure on the primary side fluctuates greatly.

[0004] Some pressure type flow rate 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 arranged in the flow path on the upstream side of the throttle portion.

[0005] As the control valve, for example, a piezo element drive type valve configured to open and close a diaphragm valve body by a piezo actuator is used. The piezo element drive type 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. In this pressure-type flow control device, the control range can be changed by switching the opening and closing of an on-off valve provided in the high flow rate flow path, enabling accurate flow control over a wide flow rate range.

[0008] However, in the pressure-type flow control device described in Patent Document 1, when the on-off valve is switched from closed to open in order to transition to a high flow rate range, gas flows into the flow path between the on-off valve and the high-flow orifice located downstream of it, which may temporarily cause a relatively large drop in the upstream pressure P1. In this case, with flow control based on the upstream pressure P1, fluctuations in the output (hunting, undershoot, overshoot) may occur when switching flow rates.

[0009] Furthermore, when switching the on-off valve from open to closed to transition to a low flow rate range, gas between the on-off valve and the orifice continues to flow out through the orifice over time even after the valve is closed. As a result, the flow rate does not decrease immediately, which can cause responsiveness problems. In addition, during the gas outflow immediately after switching, there is a discrepancy between the flow rate calculated from the upstream pressure P1 and the actual flow rate, which makes it difficult to stabilize the flow rate control immediately.

[0010] Furthermore, Patent Document 2 discloses a vaporization supply device configured to heat a liquid material introduced into a vaporizer and supply the generated material gas with flow rate control. Such a vaporization supply device requires flow rate control of a relatively high-temperature gas (for example, 150°C or higher).

[0011] However, when controlling the flow rate of high-temperature gas, extra care must be taken to prevent gas leaks. However, in a configuration where two orifice members are placed at the joint of a metal block, as described in Patent Document 1, the possibility of leaks occurring from that point increases. Therefore, when supplying high-temperature gas using a vaporization supply device, there has been a need to supply gas at an accurate flow rate over a wide flow rate control range while further reducing the possibility of leaks.

[0012] The present invention was made to solve the above problems, and its main objective is to provide a flow control device and a 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 improving the responsiveness and stability of flow control during switching, and also reducing the possibility of leaks. [Means for solving the problem]

[0013] A flow control device according to an embodiment of the present invention comprises a control valve, a small flow rate throttling section provided in the flow path downstream of the control valve, a throttling section built-in valve provided in parallel with the small flow rate throttling section in the flow path downstream of the control valve, the throttling section built-in valve having a large flow rate throttling section integrally provided in a valve mechanism that opens and closes the flow path, including a valve seat and a valve body, and the control valve, and the small flow Quantity The system includes an upstream pressure sensor that measures the fluid pressure between the throttle section and the valve built into the throttle section, and is configured to control the flow rate by controlling the opening and closing of the valve built into the throttle section and adjusting the opening degree of the control valve based on the output of the upstream pressure sensor.

[0014] In one embodiment, in the throttle-integrated valve, the large-flow throttle portion is disposed upstream of the valve seat.

[0015] In one embodiment, each of the small-flow throttle portion and the large-flow throttle portion includes an orifice plate.

[0016] The vaporization supply device according to an embodiment of the present invention includes a vaporizer and any one of the above-described flow rate control devices connected to the downstream side of the vaporizer.

[0017] In one 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

[0018] According to the flow rate control device and the vaporization supply device according to an embodiment of the present invention, it is possible to appropriately control 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

[0019] [Figure 1] It is a schematic diagram showing a gas supply system including a vaporization supply device according to an embodiment of the present invention. [Figure 2] It is a side view showing a specific configuration example of a vaporization supply device according to an embodiment of the present invention. [Figure 3] It is a cross-sectional view showing a throttle-integrated valve included in a flow rate control device according to an embodiment of the present invention. [Figure 4] It is a cross-sectional view showing a throttle-integrated valve of another aspect included in a flow rate control device according to an embodiment of the present invention. [Figure 5] It is a cross-sectional view showing a specific configuration example of a control valve included in a flow rate control device according to an embodiment of the present invention. [Figure 6] It is a diagram for explaining the operation when performing flow rate control while changing the control flow rate range, and shows the operation, upstream pressure, and flow rate of the throttle-integrated valve. [Modes for carrying out the invention]

[0020] Embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the following embodiments.

[0021] Figure 1 shows a gas supply system 100 incorporating 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.

[0022] The gas supply system 100 is configured to vaporize the liquid material L sent from the liquid material source 2 in the vaporization supply device 50, and then supply the resulting material gas G to the process chamber 6 with flow rate control. In Figure 1, the supply path for the liquid material L is shown by a thick solid line, and the supply path for the material gas G is shown by a thick dashed line.

[0023] 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.

[0024] 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, for example, a silicon nitride film (SiN x It is used to form insulating films such as silicon oxide films (SiO2 films).

[0025] 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 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.

[0026] Figure 2 shows a specific configuration example of the vaporization supply device 50. As shown in Figures 1 and 2, the vaporization supply device 50 of this embodiment includes a vaporizer 10 and a flow rate control device 20 provided downstream of the vaporizer 10.

[0027] 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, with a heater (not shown). As shown in Figure 2, the vaporizer 10 may include a preheating section 14, a vaporization section 16, and a liquid replenishment valve 18 provided in the flow path between them. By preheating the liquid material L in the preheating section 14 to a temperature that does not cause vaporization, vaporization in the vaporization section 16 can be facilitated. This suppresses the decrease in liquid temperature in the vaporization chamber 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.

[0028] 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 unit 16 is sufficient. When the supply pressure P0 falls below a threshold, the liquid replenishment valve 18 can be opened to replenish the liquid material, allowing for stable gas generation in the vaporization unit 16.

[0029] 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 unit 16. By providing a liquid detection unit, it is possible to prevent oversupply of liquid material L to the vaporization unit 16. 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.

[0030] The following describes the detailed configuration of the flow rate control device 20 for controlling the flow rate of the material gas G generated using the vaporizer 10.

[0031] As shown in Figures 1 and 2, the flow control device 20 of this embodiment includes a control valve 22, an upstream pressure sensor 24 provided downstream of the control valve 22, and a large flow path PL and a small flow path PS that branch off downstream of the control valve 22 and then rejoin. The flow control device 20 may also include a temperature sensor (not shown) for measuring the gas temperature downstream of the control valve 22.

[0032] 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 upstream 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 thermistor or a platinum resistance thermometer can be used.

[0033] In the flow control device 20, a valve with a built-in throttle section 26 is provided in the high-flow flow path PL. The valve with a built-in throttle section 26 is an on-off valve in which a high-flow throttle section 27L (see Figures 3 and 4) is provided near the valve seat of the internal flow path, and in the valve with a built-in throttle section 26, the valve mechanism (valve seat and valve body) that opens and closes the flow path and the high-flow throttle section 27L are provided integrally.

[0034] On the other hand, a small flow rate throttling section 27S is provided in the small flow rate channel PS. While the large flow rate throttling section 27L is incorporated into the throttling section built into the valve 26, the small flow rate throttling section 27S is sealed and fixed at the connection part of the flow path block as a gasket orifice, for example, as shown in Figure 2. The opening area of ​​the large flow rate throttling section 27L is typically set to be larger than the opening area of ​​the small flow rate throttling section 27S, but they may be the same.

[0035] In this embodiment, the large flow rate throttling section 27L and the small flow rate throttling section 27S are constructed using orifice plates. The orifice diameter of the large flow rate throttling section 27L is set to, for example, approximately 180 μm to 2200 μm, and the orifice diameter of the small flow rate throttling section 27S is set to, for example, approximately 40 μm to 1500 μm. However, critical nozzles or sonic nozzles can also be used as throttling sections 27S and 27L.

[0036] Furthermore, in this embodiment, the throttling valve 26 is configured such that the valve body operates and opens and closes the flow path when compressed air is supplied to the drive unit. As shown in Figure 1, a solenoid valve 29 that controls the supply of compressed air is connected to the throttling valve 26, and the opening and closing of the throttling valve 26 can be performed quickly by controlling the solenoid valve 29. However, it is not limited to this, and the throttling valve 26 is configured , electric It may also be configured using other types of on / off valves, such as a valve train.

[0037] The flow control device 20 described above is configured to control the flow rate of gas G' flowing downstream of the small flow restriction section 27S and the large flow restriction section 27L (or the valve 26 built into the restriction section) by adjusting the opening degree of the control valve 22 based on the output of the upstream pressure sensor 24, and thus constitutes a pressure-type flow control device. When the valve 26 built into the restriction section is closed, the flow control device 20 can supply gas at a low flow rate because gas flows only through the small flow path PS. When the valve 26 built into the restriction section is opened, gas flows mainly through the large flow path PL (or both the large flow path PL and the small flow path PS depending on the diameter ratio of the restriction sections 27L and 27S), so the flow control device 20 can supply gas at a high flow rate.

[0038] 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 (pressure downstream of the throttling section).

[0039] 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.)

[0040] Here, the flow rate control device 20 is configured to calculate the flow rate using a flow rate calculation formula for large flow rates (specifically, a formula using constants corresponding to the sum of the opening areas of the large flow rate throttling section and the small flow rate throttling section as K1 or K2 above) when the valve 26 built into the throttling section is open, and to calculate the flow rate using a flow rate calculation formula for small flow rates (specifically, a formula using constants corresponding to the opening area of ​​the small flow rate throttling section as K1 or K2 above) when the valve 26 built into the throttling section is closed. Therefore, in either case, the flow rate downstream of the throttling section can be controlled by controlling the upstream pressure P1.

[0041] To control the flow rate, a set flow rate Qs is input to a control circuit (not shown). The control circuit calculates a calculated flow rate Qc according to the above formula, based on the opening and closing status of the valve 26 built into the throttle section and the output of the upstream pressure sensor 24. The control valve 22 is then feedback controlled 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.

[0042] Here, a more specific example of the configuration of the throttling valve 26 will be described. Figures 3 and 4 are enlarged cross-sectional views showing the vicinity of the valve body of the throttling valve 26 (here, an orifice-integrated valve) provided in the high-flow passage PL, and each shows a different configuration example. As shown in Figures 3 and 4, in the throttling valve 26, a high-flow throttling section 27L (here, an orifice plate) having an opening 27O is provided in the internal passage near the valve seat (or valve seat member 26S). The configuration of the orifice-integrated valve itself is shown in, for example, Patent Document 3, and a similar configuration can be adopted in this embodiment.

[0043] As shown in Figures 3 and 4, in the valve 26 with a built-in throttle, a large-flow throttle 27L is integrally provided with the valve mechanism, which is composed of a valve seat (or valve seat member 26S) and a valve body 26V and can open and close the flow path. Here, "integrally provided" broadly means that the valve mechanism and the large-flow throttle 27L are arranged together at a common mounting position (typically a recess) in the flow path block, and that the valve mechanism and the throttle are not arranged separately at distant positions in the flow path block. When it is said that they are "integrally provided", it is sufficient that the diaphragm valve body 26V (or valve seat member 26S) and the large-flow throttle 27L are arranged together at the same mounting position, and they do not need to be fixed to each other. Furthermore, this does not exclude the possibility of other optional members being interposed between the valve mechanism (e.g., valve seat member 26S) and the throttle 27L (or throttle member including a support member that fixes it).

[0044] The valve 26 with a built-in throttle is configured to close by pressing the diaphragm valve body 26V against the valve seat (in this case, an annular contact surface formed on the upper surface of the valve seat member 26S) with the actuator piston 26A. The actuator piston 26A can be moved up and down using compressed air. When compressed air is not supplied, the valve can be opened by using the self-restoring force of the diaphragm valve body 26V by moving the piston 26A in the release direction with an elastic member (not shown).

[0045] By using such a valve 26 with an integrated throttle, the flow path volume 26C between the diaphragm valve body 26V and the large flow rate throttle section 27L when the valve is closed can be designed to be extremely small (for example, 0.05 cc or less). The flow path volume 26C is sufficiently small compared to the flow path volume between the control valve 22 and the large flow rate throttle section 27L and the small flow rate throttle section 27S, for example, 1 / 30 or less.

[0046] Therefore, when the valve is closed, the amount of gas flowing into the flow path volume 26C through the throttling section 27L is small, and there is almost no temporary drop in the upstream pressure P1. Also, when the valve is opened, the amount of gas flowing out of the flow path volume 26C is very small and can be almost ignored. As a result, fluctuations in the flow output (hunting, undershoot, overshoot) that may occur when switching to flow control in the low flow range by closing the valve 26 built into the throttling section, or when switching to flow control in the high flow range by opening the valve 26 built into the throttling section, are suppressed, and highly responsive and stable flow control can be performed after the switch.

[0047] Furthermore, since the valve 26 with a built-in throttle can be fixed by sandwiching the large-flow throttle section 27L between itself and the main body block below it, it is easy to design a valve with high sealing performance even while having a large-flow throttle section 27L. In particular, as shown in Figures 3 and 4, if a configuration is adopted in which the large-flow throttle section 27L is sandwiched between two metal members whose protrusions and recesses can be fitted together, the ease of assembly is improved, and sealing performance is further enhanced, making it possible to more effectively reduce the occurrence of gas leaks from the fixing point of the large-flow throttle section 27L.

[0048] Furthermore, by fixing the valve seat member 26S (which may be made of metal or resin) to the main body block while pressing it down with a retaining member 26P having a gas passage around its periphery, a gas flow path can be formed while ensuring a firm fixation, and the overall sealing performance of the throttling valve 26 can also be improved. Therefore, by using the throttling valve 26, the possibility of leakage can be reduced even when relatively high-temperature gas flows from the vaporizer 10.

[0049] In the configuration shown in Figure 3, the diameter of the valve seat member 26S is larger than the diameter of the metal member (sometimes collectively called the throttling member) that clamps the throttling portion 27L, and the valve seat member 26S is provided so as to cover the upper side of the metal member. In contrast, in the configuration shown in Figure 4, the diameter of the valve seat member 26S is smaller than the diameter of the throttling member, and the valve seat member 26S is fixed by being strongly pressed against the throttling member by a retaining member 26P, for example, a resin valve seat member 26S. When the size of the throttling member and the size of the valve mechanism (piston portion 26A, etc.) are relatively close, the configuration shown in Figure 4, which allows for a compact design, can be adopted. However, when it is desired to further suppress leakage that may occur around the throttling member between the inlet and outlet flow paths when the valve is closed, the configuration shown in Figure 3 can be adopted. However, as long as the throttling portion 27L is located near the valve seat and the flow path volume 26C can be designed to be small, the valve 26 with a built-in throttling portion can take on various other configurations.

[0050] Furthermore, as shown in Figures 3 and 4, in this embodiment, in the throttling valve 26, the material gas G flows in from the central part of the throttling valve 26 and flows out from the peripheral part. In this configuration, the high-flow throttling section 27L is located upstream of the valve seat and valve body. As a result, when switching to a low-flow range, the gas flow from the high-flow flow path PL is immediately shut off after the valve is closed, and there is no gas outflow from the flow path volume 26C. Therefore, the advantage is obtained that control can be switched to the low-flow range with better responsiveness. However, this is not limited to this, and the high-flow throttling section 27L may be located downstream of the valve seat and valve body by designing the flow path so that a gas inlet is provided in the peripheral part of the throttling valve 26 and a gas outlet is provided in the central part.

[0051] Next, a specific example of the control valve 22 provided in the flow control device 20 will be described. The control valve 22 may be configured using a conventional piezoelectric element-driven valve, or a valve 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 made of, for example, Invar material, and by moving it in conjunction with the piezoelectric actuator, it is possible to properly control the flow rate while preventing the piezoelectric element from exceeding its heat resistance temperature even when high-temperature gas flows through the gas flow path.

[0052] However, in order to control a wider control range, particularly at higher flow rates, a diaphragm valve equipped with multiple actuators, as shown in Figure 5, can also be used as the control valve 22 of the flow control device 20. Such a valve is disclosed, for example, in Patent Document 4 by the present applicant.

[0053] As shown in Figure 5, the control valve 22 of this embodiment includes an operating member 42 for opening and closing the diaphragm valve body 44, a main actuator 40 for moving the operating member 42 a relatively large distance, and a sub-actuator 41 for moving the operating member 42 a relatively small distance. A valve body retainer 45 that contacts the diaphragm valve body 44 is fixed to the tip of the operating member 42.

[0054] The main actuator 40, the sub-actuator 41, and the operating member 42 are all housed inside the valve housing 43. The valve housing 43 is fixed to the flow path block and is an immovable component relative to the flow path block. On the other hand, the operating member 42 is provided to be movable inside the valve housing 43.

[0055] The main actuator 40 is an air-driven actuator (an actuator operated by a driving fluid) that moves the operating member 42 up and down. The main actuator 40 is composed of a plurality of annular pistons, and these annular pistons are movable vertically together with the operating member 42. Compressed air is supplied as the driving fluid to the pressure chamber of the main actuator 40 via a supply pipe 47. By controlling the air pressure of the supplied compressed air using a pressure regulator such as an electro-pneumatic regulator, the amount of movement of the operating member 42 and the opening degree of the diaphragm valve body 44 can be controlled.

[0056] Furthermore, a piezo actuator (an actuator that can be extended by electrical drive) is used as the sub-actuator 41. The sub-actuator 41 is slidably mounted inside the operating member 42 so as to be relative to the operating member 42. By controlling the voltage applied to the sub-actuator 41, the amount of movement of the operating member 42 and the opening degree of the diaphragm valve body 44 can be controlled more precisely.

[0057] figure 5 The control valve 22 shown is a normally closed type valve, and when the main actuator 40 and the sub-actuator 41 are not driven, the diaphragm valve body 44 is pressed against the valve seat via the operating member 42 by a biasing force received from the coil spring 46 and the disc spring 48 located between the upper surface of the sub-actuator 41 and the valve housing 43 (lid portion).

[0058] On the other hand, when opening the valve, compressed air with a pressure corresponding to the opening degree is supplied to the main actuator 40, lifting the operating member 42 upward against the biasing force of the coil spring 46 and the disc spring 48. This allows the diaphragm valve body 44 to be opened to approximately the desired degree.

[0059] Furthermore, the drive by the main actuator 40 causes not only the operating member 42 but also the sub-actuator 41 located inside it to move upward. At this time, by controlling the voltage applied to the sub-actuator 41 and thus its extension, the downward biasing force can be increased. This allows for fine adjustment of the displacement of the operating member 42 in the downward direction.

[0060] Therefore, by controlling both the operating pressure of the main actuator 40 and the applied voltage of the sub-actuator 41 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 40 enables the flow of large gas flow rates, and the sub-actuator 41 allows for highly responsive fine adjustment, so when used as a control valve 22, the upstream pressure P1 can be appropriately controlled to a desired value over a wide range.

[0061] The following describes an example of flow control operation involving a change in the control flow range, performed using the flow control device 20, with reference to Figure 6.

[0062] As shown in Figure 6, first, the control valve 22 and the valve 26 built into the throttle section 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 low flow rate range. During flow rate control, the control valve 22 is feedback controlled based on the upstream pressure P1 measured by the upstream pressure sensor 24, thereby maintaining a constant upstream pressure P1 and, consequently, a constant flow rate Q. During this period, the valve 26 built into the throttle section is closed, and gas is supplied only through the low flow rate channel PS.

[0063] Next, at time t2, the flow rate control is switched to the high flow rate range. At this time, the valve 26 built into the throttle opens instantaneously, and gas supply is started via the high flow rate channel PL. Also, at this time, even with a lower upstream pressure P1, gas can be flowed 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 continue to flow at an even higher flow rate.

[0064] Furthermore, when controlling the flow rate of the gas generated using 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 (and in particular the control valve 22 shown in Figure 5) makes it possible to flow a larger flow rate of gas at a desired flow rate than conventional methods, 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 and maintain it at a value higher than the upstream pressure P1.

[0065] Furthermore, at time t3, the flow control is switched back to the low flow rate range. At this time, the valve 26 built into the throttle section is instantaneously closed, and gas supply via the low flow rate channel PS is started. The upstream pressure P1 is maintained at any pressure that can achieve the desired flow rate through feedback control of the control valve 22.

[0066] 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 high flow rate throttle section 27L is located near the valve seat of the internal flow path of the built-in throttle valve 26. This prevents fluctuations in output during switching, enabling stable and responsive flow rate control.

[0067] Although embodiments of the present invention have been described above, various modifications are possible. For example, although an embodiment in which two flow paths, a small flow path PS and a large flow path PL, are connected in parallel downstream of the control valve has been described above, three or more flow paths may be connected in parallel. In this case as well, by arranging a valve with a built-in throttle in the flow paths other than the small flow path, it is possible to switch between multiple control ranges and to perform stable flow control even when switching ranges. [Industrial applicability]

[0068] The flow rate control device and vaporization supply device according to embodiments of the present invention are suitably used, for example, to be incorporated into a gas supply system such as a semiconductor manufacturing facility, in order to perform flow rate control over a wide control range. [Explanation of Symbols]

[0069] 2 Liquid material source 4. Shut-off valve 6 Process Chambers 8. Vacuum pump 10. Vaporizer 12. Supply pressure sensor 14 Preheating section 16 Vaporization section 18 Liquid refill valve 20 Flow control device 22 Control valve 24 Upstream pressure sensor 26. Valve with built-in orifice (valve with built-in orifice) 26P Retaining Member 26S Valve seat member 26V diaphragm valve body 27O opening 27L High-flow throttling section 27S Small flow restrictor 29 Solenoid valve 40 Main actuator 41 Sub-actuator 42 Operating member 43 Valve housing 44 Diaphragm valve body 50 Vaporization supply device 100 Gas supply systems P0 Supply pressure P1 Upstream pressure PL High-Flow Channel PS small flow channel

Claims

1. Control valve and A small flow rate limiting section is provided in the flow path downstream of the control valve, A valve with a built-in throttle section provided in parallel with the small flow rate throttle section in the flow path downstream of the control valve, wherein the valve mechanism for opening and closing the flow path, including the valve seat and valve body, is integrally provided with a large flow rate throttle section. The control valve and an upstream pressure sensor that measures the fluid pressure between the small flow rate throttling section and the valve built into the throttling section. Equipped with, The system is configured to control the flow rate by controlling the opening and closing of the valve built into the throttle section and by adjusting the opening degree of the control valve based on the output of the upstream pressure sensor. A flow control device wherein the valve with a built-in throttling section is mounted on a first surface of a flow path block in which branched flow paths are formed, and the small flow throttling section is mounted on a second surface of the flow path block, facing the valve with the built-in throttling section across the flow path block.

2. The flow rate control device according to claim 1, wherein in the valve with a built-in throttle, the large flow rate throttle is located upstream of the valve seat.

3. The flow control device according to claim 1 or 2, wherein each of the small flow restriction section and the large flow restriction section includes an orifice plate.

4. Vaporizer and, A flow control device according to any one of claims 1 to 3, connected to the downstream side of the vaporizer, A vaporization supply device equipped with the following features.

5. The vaporization supply device according to claim 4, further comprising a supply pressure sensor for measuring the fluid pressure between the vaporizer and the flow rate control device.

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