Flow rate control device, vaporization supply device, and method for manufacturing flow rate control device

Abstract

To provide a pressure-type flow rate control device capable of accurately controlling the flow rate in a wide pressure range without causing leakage even in high-temperature gas.SOLUTION: A flow rate control device 20 includes a control valve 22, a first pressure sensor 24 on the downstream side of the control valve, a throttle section 28 on the downstream side of the first pressure sensor, a second pressure sensor 26 on the downstream side of the throttle section, a first flow path block BL1 carrying the control valve and the first pressure sensor, and a second flow path block BL2 carrying the second pressure sensor. A gasket member is sandwiched between the first flow path block and the second flow path block. A connection hole H includes a first hole portion H1 facing the first flow path block and a second hole portion H2 having a larger cross-sectional area and extending outward, and is formed in the second flow path block. The length La of the first hole portion H1 is shorter than the distance Lb from a connection surface BLS of the first and second flow path blocks to a sealed end of the second pressure sensor.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a flow rate control device, a vaporization supply device including the same, and a method for manufacturing the flow rate control device. [Background technology]

[0002] In semiconductor manufacturing facilities, chemical plants, etc., it is required to supply raw material gases and etching gases to process chambers at desired flow rates. Known gas flow rate control devices include mass flow controllers (thermal mass flow controllers) and pressure type flow rate control devices.

[0003] Pressure type flow rate control devices are widely used because they can control the mass flow rate of various fluids with high precision using a relatively simple configuration that combines a control valve and a restrictor (such as an orifice plate or critical flow nozzle). Pressure type flow rate control devices have excellent flow rate control characteristics, allowing stable flow rate control even when the primary supply pressure fluctuates greatly.

[0004] Some pressure-type flow control devices adjust the flow rate of the fluid flowing downstream of the throttle by controlling the fluid pressure between the control valve and the throttle (hereinafter sometimes referred to as the upstream pressure P1). The upstream pressure P1 is measured by a pressure sensor installed in the flow path, and the upstream pressure P1 and therefore the mass flow rate can be controlled to a desired value by adjusting the opening of the control valve based on the output of the pressure sensor.

[0005] Also, as a pressure type flow control device, there is known a device that can control the flow rate based on the upstream pressure P1 and the downstream pressure P2 (the fluid pressure downstream of the throttling portion) (for example, Patent Document 1). With this type of flow control device, the flow rate can be controlled with high precision even when the upstream pressure P1 is not greater than the downstream pressure P2 by a critical ratio or more and the critical expansion condition is not satisfied.

[0006] On the other hand, Patent Document 2 discloses a vaporization supply device that heats a liquid material introduced into a vaporizer and supplies the generated gas with flow rate control. In the vaporizer, a liquid or solid raw material can be heated by a heater to generate a desired process gas used in semiconductor device manufacturing. The generated gas is supplied to a process chamber after its flow rate is controlled by a flow rate control device arranged downstream of the vaporizer. Such a vaporization supply device is used, for example, when forming a film by metalorganic chemical vapor deposition (MOCVD).

[0007] The flow rate of the gas generated by the vaporizer can also be controlled using the pressure-type flow rate control device. Patent documents 2 and 3 disclose an integrated vaporization supply device in which a pressure-type flow rate control device is disposed adjacent to the downstream side of the vaporizer.

[0008] The gas generated by the vaporizer is often a relatively high-temperature gas (for example, 150°C or higher). For this reason, it is preferable that the flow control device also handles high-temperature gas. In the flow control device described in Patent Document 2, the piezoelectric actuator is disposed away from the gas flow path via a heat dissipation spacer so that the control valve (typically a piezoelectric element-driven valve) is not damaged even by high-temperature gas. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] WO 03 / 058363 [Patent Document 2] International Publication No. 2016 / 174832 [Patent Document 3] International Publication No. 2019 / 021948 [Patent Document 4] International Publication No. 2022 / 137812 Summary of the Invention [Problem to be solved by the invention]

[0010] It is possible to control the flow rate of the high-temperature gas generated by the vaporizer based on the measurement of both the upstream pressure P1 and the downstream pressure P2. However, if the downstream pressure P2 is also measured, it is necessary to place pressure sensors not only upstream of the throttle but also downstream of the throttle.

[0011] However, it was found that in a flow control device in which a pressure sensor is provided downstream of the throttle section, gas leakage may occur from the location of the sensor. In particular, in a pressure type flow control device disposed downstream of the vaporizer as described above, it was found that there is an increased possibility of gas leakage occurring around the downstream pressure sensor when controlling the flow rate of high-temperature gas.

[0012] The present invention has been made to solve the above-mentioned problems, and its main object is to provide a flow control device that can prevent the occurrence of leaks even when controlling the flow rate of high-temperature gas over a wide range, an evaporation supply device equipped with the same, and a method for manufacturing such a flow control device. [Means for solving the problem]

[0013] A flow control device according to an embodiment of the present invention includes a control valve, a first pressure sensor provided in a flow path downstream of the control valve, a throttling section provided in the flow path downstream of the first pressure sensor, a second pressure sensor provided in the flow path downstream of the throttling section, a first flow path block carrying the control valve and the first pressure sensor, and a second flow path block provided adjacent to the first flow path block and carrying the second pressure sensor, and a gasket member is sandwiched at a connection portion between the first flow path block and the second flow path block, and the second flow path block extends toward the first flow path block. a connecting hole, the connecting hole including a first hole portion having a first cross-sectional area facing the first flow path block, and a second hole portion having a second cross-sectional area larger than the first cross-sectional area and extending outward from the first hole portion, a step surface is formed at the boundary between the first hole portion and the second hole portion, the second flow path block is fixed to the first flow path block by an enlarged portion of a block fixing member arranged in the connecting hole pressing the step surface of the connecting hole, and a length of the first hole portion of the connecting hole is shorter than a distance from a connection surface between the first flow path block and the second flow path block to a sealed end of the second pressure sensor.

[0014] In one embodiment, the sealing end of the second pressure sensor is defined by an outer circumferential surface of an annular gasket arranged to seal the second pressure sensor.

[0015] In one embodiment, the gasket member has a structure including the drawn portion.

[0016] In one embodiment, the gasket member is a gasket-type orifice member.

[0017] In one embodiment, the second flow path block is provided with four of the connection holes, and the block fixing members are disposed in the respective connection holes.

[0018] In one embodiment, the four connection holes include two connection holes provided on a side of the second flow path block closer to the second pressure sensor mounting surface and two connection holes provided on a side farther from the second pressure sensor mounting surface, and a flow path formed inside the second flow path block and extending from the gasket member passes through a position between the two connection holes on the side closer to the second pressure sensor mounting surface and the two connection holes on the side farther from the second pressure sensor mounting surface.

[0019] In one embodiment, the first hole portion of the connection hole is closed relative to a side surface of the second flow path block, and the second hole portion is open relative to the side surface of the second flow path block.

[0020] A vaporization supply device according to an embodiment of the present invention includes a vaporizer and the above-described flow control device connected adjacent to the downstream side of the vaporizer.

[0021] A method for manufacturing a flow control device according to an embodiment of the present invention is a method for manufacturing the above-mentioned flow control device, and includes the steps of preparing the first flow path block, the second flow path block, the block fixing member, and the second pressure sensor, fixing the second flow path block to the first flow path block using the block fixing member disposed in the connection hole formed in the second flow path block, and, after the step of fixing the second flow path block to the first flow path block, fixing the second pressure sensor to the second flow path block. Effect of the Invention

[0022] According to the pressure-type flow control device and vaporization supply device of the embodiments of the present invention, gases used in semiconductor manufacturing equipment and the like can be supplied with appropriate flow rate control over a wide control flow rate range, and the occurrence of leaks can be suppressed even when high-temperature gas is supplied. [Brief description of the drawings]

[0023] [Figure 1]1 is a schematic diagram illustrating a gas supply system including a vaporization supply device equipped with a flow control device according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a diagram showing a specific configuration example of a vaporization supply device including a flow rate control device according to an embodiment of the present invention. [Diagram 3] FIG. 11 is a perspective view showing an example of a flow path block for fixing a second pressure sensor used in the flow control device. [Figure 4] 13 is a diagram showing a manner in which a flow path block for fixing a second pressure sensor is fixed to an adjacent flow path block. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the following embodiment.

[0025] Fig. 1 shows a gas supply system 100 including a flow rate control device 20 according to an embodiment of the present invention and a vaporization supply device 50 having the flow rate control device 20 downstream of a vaporizer 10. Fig. 2 shows a specific configuration example of the vaporization supply device 50.

[0026] 1, gas supply system 100 includes a liquid material source 2, a vaporization supply apparatus 50 connected to liquid material source 2, and a process chamber 6 connected to vaporization supply apparatus 50 via a shutoff valve 4. Vaporization supply apparatus 50 includes a vaporizer 10 and a flow control device 20 provided downstream of vaporizer 10. In vaporization supply apparatus 50 shown in FIG. 2, vaporizer 10 and flow control device 20 are provided adjacent to each other and integrally, and shutoff valve 4 is also provided integrally downstream of flow control device 20.

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

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

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

[0030] The vaporization supply device 50 is provided with a plurality of heaters, and the vaporizer 10 and the flow control device 20 can be independently heated to a desired temperature. As the heater, a jacket heater or a heater that heats a metal block from the outside, such as a heater formed by inserting a cartridge heater as a heating element into an aluminum plate as a heat transfer member, can be used. Such a heater is disclosed, for example, in Patent Document 3 (International Publication No. 2019 / 021948).

[0031] The vaporizer 10 is configured to heat the liquid material L pumped from the liquid material source 2 by a heater in the vaporization chamber of the vaporization section 16 to generate the material gas G. The material gas G generated by the vaporizer 10 needs to be supplied to the process chamber 6 while being kept at a relatively high temperature so as not to be re-liquefied. In contrast, as shown in Fig. 2, if a vaporization supply device 50 having a configuration in which the vaporizer 10 and the flow rate control device 20 are integrally arranged adjacent to each other is used, the area to be maintained at a high temperature can be made compact by arranging this in the vicinity of the process chamber 6.

[0032] 2, the vaporizer 10 of this embodiment includes a preheating section 14, a vaporization section 16, and a liquid refill valve 18 provided in the flow path between them. By preheating the liquid material L in the preheating section 14 to a high temperature at which the liquid material L is not vaporized, the vaporization in the vaporization section 16 can be facilitated. This makes it possible to suppress a decrease in the liquid temperature due to the latent heat of vaporization, and to maintain the supply pressure P0 of the material gas G at a high value, making it easier to stably supply the gas.

[0033] In order to more easily maintain the preheating unit 14 and the vaporization unit 16 at different temperatures, a heat insulating member 30 may be provided between the preheating unit 14 and the vaporization unit 16. The heat insulating member 30 may be, for example, a plate made of a resin such as PEEK (Poly Ether Ether Ketone).

[0034] In addition, in the vaporization supply device 50, the supply pressure P0 of the material gas G generated in the vaporizer 10 is measured by a supply pressure sensor 12. As shown in Fig. 2, the supply pressure sensor 12 may be attached upstream of the control valve 22 in the first flow path block BL1 in which the control valve 22 and the first pressure sensor 24 constituting the flow control device 20 are attached.

[0035] By measuring the supply pressure P0 using the supply pressure sensor 12, it is possible to determine whether the amount of liquid material L in the vaporization chamber is sufficient. When the supply pressure P0 is lower than the threshold value, the liquid refill valve 18 can be opened to refill the liquid material, and gas can be generated stably in the vaporization section 16. The vaporizer 10 may also be provided with a separate liquid detection section (not shown) that can detect that the liquid material L has been supplied to the vaporization section 16 in excess of a predetermined amount. By providing the liquid detection section, it is possible to prevent oversupply of the liquid material L to the vaporization section 16. The liquid detection section is composed of, for example, a thermometer (platinum resistance thermometer, thermocouple, thermistor, etc.) arranged in the vaporization chamber, a liquid level gauge, a load cell, etc.

[0036] Hereinafter, a detailed configuration of the flow rate control device 20 for controlling the flow rate of the material gas G generated in the vaporizer 10 will be described.

[0037] 1 and 2, a flow control device 20 of this embodiment includes a control valve 22, a first pressure sensor 24 provided downstream of the control valve 22, a throttling section 28 provided in the flow path downstream of the control valve 22 and the first pressure sensor 24, and a second pressure sensor 26 provided downstream of the throttling section 28. As will be described later, in this embodiment, the throttling section 28 is configured to be included in a gasket member, and corresponds to a structure in which the gasket member sandwiched between flow path blocks has a throttling function.

[0038] The first pressure sensor (or upstream pressure sensor) 24 can measure the upstream pressure P1 between the control valve 22 and the throttle section 28, and the second pressure sensor (or downstream pressure sensor) 26 can measure the downstream pressure P2 downstream of the throttle section 28. The control valve 22, the first pressure sensor 24, and the second pressure sensor 26 are electrically connected to a control circuit (not shown).

[0039] The flow control device 20 is a pressure type flow control device, and can control the flow rate of gas flowing downstream of the throttle section 28 by controlling the opening of the control valve 22 based on the output (upstream pressure P1) of the first pressure sensor 24, or based on both the output (upstream pressure P1) of the first pressure sensor 24 and the output (downstream pressure P2) of the second pressure sensor 26. The flow control device 20 may be equipped with a temperature sensor (not shown) for measuring the temperature of the gas downstream of the control valve 22. By controlling the opening of the control valve 22 with additional reference to the output of the temperature sensor, the gas flow rate can be controlled more accurately.

[0040] As shown in Fig. 2, in this embodiment, the control valve 22 and the first pressure sensor 24 are fixed to a first flow path block BL1 on the upstream side, in which a flow path is provided. Meanwhile, the second pressure sensor 26 is fixed to a second flow path block BL2 on the downstream side, in which a flow path is provided. Here, the flow path block is typically a metal block body in which a flow path and a fluid storage space are formed, and is also called a main body block. The vaporization supply device 50 of this embodiment is fabricated by arranging a plurality of flow path blocks adjacent to each other to form a flow path, and by attaching necessary sensors and valves to the flow path block (main body block).

[0041] A throttle section 28 (or a gasket member) is disposed in a recess (here, a main recess formed in the first flow path block BL1 and a sub-recess formed in the second flow path block BL2) formed at a connection (or boundary) between the first flow path block BL1 and the second flow path block BL2. The first flow path block BL1 and the second flow path block BL2 are fixed to each other so as to sandwich the throttle section 28 at their connection surfaces. The first flow path block BL1 and the second flow path block BL2 are metal blocks made of stainless steel such as SUS316L, and gas flow paths are formed therein by drilling holes.

[0042] For example, a piezoelectric element driven valve is used as the control valve 22. A piezoelectric element driven valve is a valve capable of adjusting the amount of movement of a diaphragm valve element by controlling the voltage applied to a single piezoelectric element or multiple laminated piezoelectric elements built into a piezoelectric actuator, and is a valve capable of freely adjusting the opening degree or a proportional valve.

[0043] 2, the control valve 22 may have a configuration in which a piezoelectric actuator 22D and a rod-shaped heat dissipation spacer 22E are arranged in a line to deal with high temperatures. The heat dissipation spacer 22E is made of, for example, an Invar material, and by moving it in conjunction with the piezoelectric actuator 22D, the opening and closing of the diaphragm valve 22V (see FIG. 4) can be controlled.

[0044] In this configuration, the piezoelectric actuator 22D is prevented from being heated to a high temperature by the high-temperature gas flowing through the flow passage inside the first flow passage block BL1 or by the heat from the external heater that heats the first flow passage block BL1. Therefore, the piezoelectric element is prevented from exceeding its heat-resistant temperature, and the flow rate control can be appropriately performed while preventing damage to or malfunction of the piezoelectric actuator 22D.

[0045] In this embodiment, the throttle section 28 is configured using a gasket-type orifice member. The gasket-type orifice member has a configuration in which an orifice plate is incorporated inside a gasket member configured to be fitted into a recess in a metal block to provide a seal. The outer gasket member is made of, for example, SUS316L or PCTFE (polychlorotrifluoroethylene), and the orifice plate held inside is made of, for example, SUS316L. The orifice diameter of the throttle section 28 is set to, for example, 40 μm to 2500 μm. However, a critical nozzle or a sonic nozzle may also be used as the throttle section 28.

[0046] In this embodiment, a gasket-type orifice member is used as the throttling portion 28, and this gasket-type orifice member has both the function as the throttling portion 28 and the function as a gasket member. However, in other aspects, the throttling portion 28 and the gasket member may be installed in the first flow path block BL1 or the second flow path block BL2 as separate members. In either case, the gasket member needs to be sandwiched at the connection portion between the first flow path block BL1 and the second flow path block BL2, and is used to ensure the sealing properties of the connection portion.

[0047] By using a gasket-type orifice member as the throttle portion 28, it is possible to improve the sealing performance of the gas flow path at the boundary between the first flow path block BL1 and the second flow path block BL2, and therefore it is possible to prevent gas leakage from this connection portion.

[0048] However, in a configuration in which a gasket-type orifice member is disposed at the connection between the first flow path block BL1 and the second flow path block BL2, it is desirable to firmly fix the first flow path block BL1 and the second flow path block BL2 to each other in order to prevent gas leakage from the connection. For this reason, as described later, the second flow path block BL2 is firmly fixed to the first flow path block BL1 while being pressed against it by a block fixing member (such as a hexagon socket head bolt) inserted into a connection hole H.

[0049] For example, a silicon single crystal pressure sensor having a pressure-sensitive diaphragm provided with a strain gauge or a capacitance manometer is used as the first pressure sensor 24 and the second pressure sensor 26. For example, a pressure sensor described in Patent Document 4 (International Publication No. 2022 / 137812) can be used as the first pressure sensor 24 and the second pressure sensor 26. In addition, for example, a thermocouple, a thermistor, or a platinum resistance temperature detector is used as the temperature sensor.

[0050] In this embodiment, the shutoff valve 4 is configured using an AOV (air operated valve). The liquid refill valve 18 of the vaporizer 10 is also configured using an AOV. A solenoid valve that controls the supply of compressed air is connected to the AOV, and the shutoff valve 4 and the liquid refill valve 18 can be quickly opened and closed by controlling the solenoid valve. However, without being limited thereto, the shutoff valve 4 and the liquid refill valve 18 may be configured as an on-off valve such as a solenoid valve or a motorized valve.

[0051] 2, the shutoff valve 4 may be disposed so as to straddle the second flow path block BL2 and the subsequent block. Between the blocks (below the shutoff valve 4), for example, a heat insulating member 32 made of a PEEK plate may be provided. This makes it possible to more efficiently keep the upstream gas warm even when the shutoff valve 4 is closed to stop the gas supply, and to prevent gas re-liquefaction in the flow control device 20.

[0052] The flow control device 20 configured as above can control the flow rate by utilizing the principle that the flow rate Q is determined by the upstream pressure P1, not the downstream pressure P2, when the critical expansion condition P1 / P2≧approximately 2 (where P1 is the upstream pressure, P2 is the downstream pressure, and approximately 2 is for nitrogen gas) is satisfied. When the critical expansion condition is satisfied, the flow rate Q is calculated from Q=K1·P1 (K1 is a constant that depends on the opening area of ​​the throttle portion, the type of fluid, and the fluid temperature).

[0053] In addition, since the flow rate control device 20 is equipped with the second pressure sensor 26, even if the critical expansion condition is not satisfied, 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 throttle section, the type of fluid, and the fluid temperature, and m and n are exponents derived based on the actual flow rate.)

[0054] To perform flow control, the set flow rate Qs is input to the control circuit, which determines the calculated flow rate Qc according to the above formula based on the outputs of the first pressure sensor 24 and the second pressure sensor 26, and feedback controls the control valve 22 so that the 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.

[0055] However, the present inventors have confirmed that when the second pressure sensor 26 is fixed to the second flow path block BL2 as described above, particularly in applications where high-temperature gas is flowed, gas leakage may occur from the fixed location of the second pressure sensor 26. According to experiments by the present inventors, when the second flow path block BL2 is firmly attached to the first flow path block BL1, stress is generated in the second flow path block BL2, which is typically made of a metal such as stainless steel, causing slight deformation of the block, which is considered to result in a decrease in the sealing performance of the attachment location of the second pressure sensor 26.

[0056] Therefore, in the flow control device 20 of this embodiment, even when the second flow path block BL2 is fixed to the first flow path block BL1 by a block fixing member, stress is unlikely to be generated in the fixing portion of the second pressure sensor 26, and thus, a device is devised to maintain high sealing performance. A specific method for achieving this will be described below.

[0057] Fig. 3 is a perspective view of the second flow path block BL2, and is a diagram for explaining the difference between the configuration of the comparative example and the configuration of the example. Fig. 4 is a diagram showing a fixing manner of the first flow path block BL1 and the second flow path block BL2 in this embodiment.

[0058] 3, the upper surface of the second flow path block BL2 is provided with a recess 26H for fixing the second pressure sensor 26 and an outlet 4H. The recess 26H and the outlet 4H are connected to a flow path formed in the block. The outlet 4H is connected to the upstream flow path of the shutoff valve 4.

[0059] The second flow path block BL2 is formed with a connection hole H for connection to the first flow path block BL1. The connection hole H extends horizontally (in the block connection direction) toward the first flow path block BL1. The connection hole H is composed of a first hole portion H1 having a first cross-sectional area facing the first flow path block BL1, and a second hole portion H2 having a larger diameter (larger second cross-sectional area) that extends outward as an extension of the first hole portion H1. A step surface (the bottom surface of the second hole portion H2) is formed at the boundary between the first hole portion H1 and the second hole portion H2.

[0060] For convenience, the direction in which the blocks are lined up is sometimes referred to as the horizontal direction, and the direction perpendicular to this on the plane of the paper in Fig. 2 is sometimes referred to as the vertical direction or up-down direction. However, it goes without saying that the actual horizontal and vertical directions may differ depending on the attitude and mounting direction of vaporization supply device 50. Also, for convenience, the surface corresponding to the block connection surface is sometimes referred to as the end surface of the block, the surface on which elements, etc. are mounted is sometimes referred to as the upper and lower surfaces of the block, and the lateral surface between the upper and lower surfaces (the surface perpendicular to the end surface) is sometimes referred to as the side surface of the block.

[0061] In the embodiment shown in Fig. 3, four connection holes H are provided in the second flow path block BL2. The four connection holes H are formed in parallel, two on each side of the second flow path block BL2, spaced apart in the up-down direction. This allows the second flow path block BL2 to be firmly fixed to the first flow path block BL1 at four points. In addition, it allows the second flow path block BL2 to be fixed evenly with relatively uniform force in the up-down and left-right directions.

[0062] Also, the first hole portion H1 of each connection hole H is closed to the side surface of the second flow path block BL2, i.e., it is a through hole extending inside the block. Meanwhile, the second hole portion H2 having a larger diameter is open to the side surface of the second flow path block BL2, and the second hole portion H2 is accessible from the block side surface. Therefore, the fastening of a fixing member such as a bolt inserted into the first hole portion H1 can be performed reliably and securely, and the fastening operation of the fixing member can be performed more easily in the second hole portion H2. However, this is not limited thereto, and the second hole portion H2 may also be a hole that is closed to the block side surface.

[0063] 3, the horizontal length La of the first hole portion H1 of the connection hole H (upper side) of the embodiment is smaller than the horizontal length La' of the first hole portion H1 of the connection hole H (lower side) of the comparative example. In other words, the depth of the countersink of the connection hole H of the embodiment is deeper than the depth of the countersink (second hole portion H2) of the connection hole H of the comparative example. Note that the countersink is a hole in an enlarged diameter portion, which is a portion that is dug down with a larger diameter so that the head of a fixing member such as a screw or bolt to be installed does not protrude.

[0064] By thus boring the countersink deeper than in the comparative example, the stress generated in the second flow path block BL2 when the second flow path block BL2 is fixed to the first flow path block BL1 by a bolt or the like can be concentrated in the vicinity of the first flow path block BL1. This makes it possible to suppress the occurrence of stress and distortion in the vicinity of the recess 26H for fixing the second pressure sensor 26, and to prevent the occurrence of gas leakage from the mounting portion of the second pressure sensor 26.

[0065] Fig. 4 is a diagram showing a manner in which the second flow path block BL2 is fixed to the first flow path block BL1 using a block fixing member 29 in this embodiment. As shown in Fig. 4, the block fixing member 29 is inserted into a connection hole H in the second flow path block BL2, which is composed of a small-diameter first hole portion H1 and a larger-diameter second hole portion H2. In this embodiment, the block fixing member 29 is a hexagon socket bolt having an enlarged diameter portion (or head portion) 29H, and its tip portion is inserted into a receiving hole formed in the first flow path block BL1.

[0066] In this embodiment, a screw is formed on the insertion portion of the block fixing member 29, and also on the receiving hole. Therefore, by rotating the enlarged diameter portion 29H, the block fixing member 29 can be advanced toward the first flow path block BL1. Although not shown, a washer may be disposed between the enlarged diameter portion 29H and the step surface HS of the connection hole H (the bottom surface of the second hole portion H2).

[0067] In addition, after the enlarged diameter portion 29H comes into contact with the step surface HS, the enlarged diameter portion 29H can be further rotated to press the step surface HS, thereby firmly fixing the second flow path block BL2 to the first flow path block BL1. This makes it possible to prevent gas leakage from the connection surface BLS even in a configuration in which the throttle portion 28 is disposed at the block boundary.

[0068] However, a relatively large stress is generated in the second flow path block BL2 due to strong fastening by the block fixing member 29. In response to this, in the flow control device 20 of this embodiment, the length La of the first hole portion H1 is set to be shorter than the distance Lb from the connection surface BLS between the first flow path block BL1 and the second flow path block BL2 to the sealed end of the second pressure sensor 26, thereby making it difficult for the stress to be transmitted to the sealed end of the second pressure sensor 26. This maintains the sealing performance of the second pressure sensor 26 and makes it difficult for gas leaks to occur.

[0069] Here, the second pressure sensor 26 used in this embodiment is fixed to the mounting surface of the sensor body 26S to the second flow path block BL2 with a ring-shaped gasket 26G sandwiched therebetween to ensure sealing. In this embodiment, the outer peripheral surface of this gasket 26G is defined as the sealing end of the second pressure sensor 26. However, in cases where a gasket is not used, the sealing end of the second pressure sensor 26 may be the outer peripheral surface of the sealing portion closest to the flow path, which is a portion of the second pressure sensor 26 fitted into a recess formed in the second flow path block BL2 that abuts against the second flow path block BL2 to form a seal.

[0070] As described above, the length La of the first hole portion H1 is set to be relatively short (i.e., the countersink is set to be relatively deep), so that a stress buffer portion having a distance Lc is provided between the step surface HS, which directly receives the force from the enlarged diameter portion 29H of the block fixing member 29, and the outer circumferential surface of the gasket 26G. This makes it possible to prevent slight distortion of the second flow path block BL2 near the gasket 26G when the block fixing member 29 is tightened, and maintain the sealing performance.

[0071] 4, a gasket guide ring 26R may be provided around gasket 26G, and sensor body 26S may be held by sensor bonnet 26B shaped to cover sensor body 26S via a co-rotation prevention washer. By fitting a screw formed on the outer circumferential surface of sensor bonnet 26B to a screw formed on the inner circumferential surface of recess 26H (see FIG. 3) of second flow path block BL2 and rotating sensor bonnet 26B, sensor body 26S can be firmly fixed to second flow path block BL2 with high sealing performance while pressing gasket 26G.

[0072] 3, the connection hole H may include two connection holes provided on the side closer to the second pressure sensor mounting surface and two connection holes provided on the side farther from the second pressure sensor mounting surface, and in this case, as shown in FIG. 4, the flow path extending from the throttle portion 28 may pass through the center part of the block between the connection hole on the side closer to the mounting surface and the connection hole on the side farther from the mounting surface. As a result, when viewed from the end face direction, the four connection holes and the block fixing member to be inserted are evenly distributed around the flow path, and the second flow path block BL2 can be pressed and fixed to the first flow path block BL1 with a uniform force in terms of the surface without unnecessarily increasing the size of the second flow path block BL2. In this case, too, the length La of the first hole portion H1 (or the distance between the connection surface BLS and the step surface HS) is made smaller than the distance Lb to the seal end of the second pressure sensor 26, so that the stress caused by the tightening of each block fixing member is not easily transmitted to the seal end of the second pressure sensor 26, and therefore the sealability of the second pressure sensor 26 can be maintained high. Furthermore, as long as there is no problem with fixation, the number of connection holes H may be one or more than two.

[0073] Next, in the method for manufacturing the flow control device 20 described above, a method for further reducing the occurrence of gas leakage from the fixing point of the second pressure sensor 26 will be described.

[0074] In connecting the flow path blocks, usually, pressure sensors, control valves, etc. are fixed to the flow path blocks beforehand, and then the flow path blocks are connected. However, in the manufacturing method of the flow control device 20 according to the present embodiment, the second pressure sensor 26 is fixed to the second flow path block BL2 after the second flow path block BL2 is fixed to the first flow path block BL1.

[0075] More specifically, first, a first flow path block BL1 to which the control valve 22, the supply pressure sensor 12, and the first pressure sensor are attached is prepared. Next, a second flow path block BL2 to which the second pressure sensor 26 is not fixed is prepared, and after a gasket member (throttled portion 28 in this case) is interposed, this is firmly fixed to the first flow path block BL1 by the block fixing member 29 using the connection hole H. At this time, stress may be generated in the second flow path block BL2 due to the fixing by the block fixing member 29, but since the step surface HS is formed in a position close to the first flow path block BL1 as described above, it is possible to reduce the occurrence of distortion at the fixing point of the second pressure sensor 26.

[0076] Then, after the second flow path block BL2 is fixed to the first flow path block BL1, the second pressure sensor 26 is fixed to the second flow path block BL2. As described above, the second pressure sensor 26 can be fixed by arranging the sensor main body 26S in the recess of the second flow path block BL2 via the gasket 26G, and by covering it with the sensor bonnet 26B from above and rotating it.

[0077] It was found that the method of fixing the second pressure sensor 26 to the second flow path block BL2, which has already been fixed to the first flow path block BL1 in this way, can further suppress the occurrence of gas leakage from the attachment point of the second pressure sensor 26. The reason for this is considered to be that even if some distortion occurs in the second flow path block BL2 before the attachment of the second pressure sensor 26, the gasket 26G is appropriately deformed during the process of fixing the second pressure sensor 26, and the sealing performance is restored. Therefore, the manufacturing method in which the second pressure sensor 26 is attached later can more effectively prevent the occurrence of gas leakage.

[0078] Although the embodiment of the present invention has been described above, various modifications are possible. For example, the above describes a connection hole H that is configured by a first hole portion H1 having a first diameter and a second hole portion H2 having a larger second diameter, but is not limited to this. The second hole portion H2 does not necessarily have to have an elongated hole shape, and may be, for example, a groove or a recess formed in the side surface of the second flow path block BL2. The formed groove or recess does not have to reach the downstream end face of the second flow path block BL2. As long as the cross-sectional area of ​​the second hole portion H2 is larger than the cross-sectional area of ​​the first hole portion H1 and a step surface HS is formed at the boundary between them, the shape of the first hole portion H1 may be arbitrary. [Industrial Applicability]

[0079] The flow rate control device and vaporization supply device according to the embodiments of the present invention are incorporated into a gas supply system of a semiconductor manufacturing facility or the like and are appropriately used to perform flow rate control over a wide control range. [Explanation of symbols]

[0080] 2 Liquid material source 4. Shutoff valve 6 Process Chamber 8. Vacuum Pump 10. Carburetor 12 Supply pressure sensor 20 Flow Control Device 22 Control valve 24 First pressure sensor 26 Second pressure sensor 28 Squeezing part (gasket material) 29 Block fixing member 29H Enlarged diameter part of block fixing member (head) 50 Vaporizing Supply Device 100 Gas Supply System BL1 First flow path block BL2 Second flow path block H Connection hole H1 1st hole part H2 2nd hole part HS step surface P0 supply pressure P1 Upstream pressure P2 downstream pressure

Claims

1. A control valve; a first pressure sensor provided in a flow path downstream of the control valve; a throttle portion provided in a flow path downstream of the first pressure sensor; A second pressure sensor provided in the flow path downstream of the throttle portion; a first flow path block carrying the control valve and the first pressure sensor; a second flow path block provided adjacent to the first flow path block and carrying the second pressure sensor; A flow control device comprising: a gasket member sandwiched at a connection portion between the first flow path block and the second flow path block, the second flow path block has a connection hole extending toward the first flow path block, the connection hole including a first hole portion having a first cross-sectional area and facing the first flow path block, and a second hole portion having a second cross-sectional area larger than the first cross-sectional area and extending outward from the first hole portion, a step surface being formed at a boundary between the first hole portion and the second hole portion, the second flow path block is fixed to the first flow path block by pressing the step surface of the connection hole with an enlarged diameter portion of a block fixing member disposed in the connection hole, A flow control device, wherein a length of the first hole portion of the connection hole is shorter than a distance from a connection surface between the first flow path block and the second flow path block to a sealed end of the second pressure sensor.

2. The flow control device of claim 1 , wherein the sealing end of the second pressure sensor is defined by an outer circumferential surface of an annular gasket disposed to seal the second pressure sensor.

3. The flow control device according to claim 1 , wherein the gasket member has a structure including the throttle portion.

4. The flow control device according to claim 3 , wherein the gasket member is a gasket-type orifice member.

5. The flow rate control device according to claim 1 , wherein the second flow path block is provided with four of the connection holes, and the block fixing member is disposed in each of the connection holes.

6. 6. The flow control device according to claim 5, wherein the four connection holes include two connection holes provided on a side closer to the second pressure sensor mounting surface of the second flow path block and two connection holes provided on a side farther from the second pressure sensor mounting surface, and a flow path formed inside the second flow path block and extending from the gasket member passes through a position between the two connection holes on the side closer to the second pressure sensor mounting surface and the two connection holes on the side farther from the second pressure sensor mounting surface.

7. 5. The flow control device according to claim 1, wherein the first hole portion of the connection hole is closed to a side surface of the second flow path block, and the second hole portion is open to a side surface of the second flow path block.

8. A vaporizer; a flow rate control device according to any one of claims 1 to 4, which is adjacently connected to the downstream side of the vaporizer; A vaporization supply device comprising:

9. A method for manufacturing a flow control device according to any one of claims 1 to 4, comprising the steps of: preparing the first flow path block, the second flow path block, the block fixing member, and the second pressure sensor; fixing the second flow path block to the first flow path block by using the block fixing member disposed in the connection hole formed in the second flow path block; a step of fixing the second pressure sensor to the second flow path block after the step of fixing the second flow path block to the first flow path block; A method for manufacturing a flow control device, comprising:

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