JP7242029B2 - Solenoid valves, flow control devices, fluid control devices and semiconductor manufacturing equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to a solenoid valve, a flow control device using the same, a flow control method, a fluid control device, a semiconductor manufacturing apparatus, and a semiconductor manufacturing method.

For example, in a semiconductor manufacturing process, a flow control device is used to control the supply flow rate of various process gases to a chamber of a semiconductor manufacturing apparatus.
In semiconductor manufacturing processes such as ALD (Atomic Layer Deposition), the processing gas used in the process of depositing a film on a substrate is supplied at a higher flow rate and with higher precision control. is required.
Piezo actuators and solenoid actuators are known as actuators for control valves used in flow control devices, but solenoid actuators, which have a larger stroke than piezo actuators, are more suitable for controlling large flow rates. ing.
In a solenoid valve using a solenoid actuator, a valve element called a disc is constantly pressed against a valve seat formed in a valve body by the biasing force of a spring. Then, when a voltage corresponding to the target flow rate is applied to the solenoid of the solenoid actuator, the valve is separated from the valve seat to open the valve, and the fluid is controlled to achieve the target flow rate.

JP 2014-185734 A JP 2007-146914 A JP 2003-343744 A

In the above flow control device using a solenoid valve, when controlling the flow rate to zero or when shutting off the flow path in an emergency, the valve body is pressed against the valve seat with the force of the spring to close the flow path. .
However, it is difficult to reliably close the valve when a high-pressure fluid is circulating due to line contact simply by pressing the valve body against the valve seat with the force of the spring. Further, in the solenoid valve, since the contact position of the valve body with respect to the valve seat varies, a slight gap may be formed between the valve seat and the valve body, allowing fluid to flow. If the fluid flows between the valve seat and the valve body, it is difficult to achieve highly accurate flow rate control.
Therefore, it is necessary to improve the sealing performance when the valve is closed.
Patent Literature 1 discloses a technique for improving sealing performance when a valve is closed by forming an annular chamfering trace on a coated valve seat.
Patent document 2 describes a solenoid valve composed of a spherical valve body and a valve seat forming a tapered opening, wherein a spherical jig is used to form a spherical indentation on the valve seat to reduce the pressure when the valve is closed. It discloses a technique for enhancing sealing performance.
Patent Literature 3 discloses a technique of improving the sealing performance when the valve is closed by providing a seal member made of expanded graphite at a position corresponding to the valve seat of the valve body.
However, the techniques of Patent Documents 1 and 2 are difficult to apply to valve bodies having shapes other than a spherical shape. The technique of Patent Document 3 has problems such as a complicated structure and easy generation of particles.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and one of its objects is to provide a solenoid valve with improved sealing performance when the valve is closed.
Another object of the present invention is to provide a flow control device, a flow control method, a fluid control device, a semiconductor manufacturing device, and a semiconductor manufacturing method using the above solenoid valve.

A solenoid valve according to the present invention comprises an annular valve seat made of a metal alloy, a valve body made of a metal alloy provided so as to be able to contact and separate from the valve seat, and a solenoid actuator for driving the valve body. a solenoid valve having
either the valve body or the valve seat has a sealing surface with a convex curved surface;
the other of the valve body and the valve seat has an annular groove facing the sealing surface and having a concavely curved surface that matches the curved surface of the sealing surface;
In the solenoid valve, a difference in hardness is provided between the contact portion of the valve body and the valve seat, and the sealing surface is formed to have a hardness higher than that of the annular groove.

Preferably, the valve seat further has an inclined surface that continues on the outer peripheral side of the curved surface of the seal surface and that is inclined so as to widen toward the root portion of the valve seat,
A configuration can be adopted in which the annular groove of the valve body further has an inclined surface portion that matches a portion of the inclined surface.
More preferably, the sealing surface may have an arc-shaped curved surface.

Preferably, the hardness of the valve seat is Hv300 or more,
The hardness of at least the portion of the valve body that contacts the valve seat may be in the range of Hv100 to Hv140.

A method for manufacturing a solenoid valve according to the present invention is the method for manufacturing the solenoid valve described above,
The valve body is pressed against the valve seat to plastically deform the valve body to form the annular groove.

A flow control device according to the present invention incorporates the above solenoid valve as a flow control valve.

A flow rate control method according to the present invention controls the flow rate of a fluid using the solenoid valve described above.

A fluid control device according to the present invention is a fluid control device in which a plurality of fluid devices are arranged,
The plurality of fluid devices include the solenoid valves or flow control devices described above.

A semiconductor manufacturing method according to the present invention uses the above-described solenoid valve to control the flow rate of a process gas in a semiconductor device manufacturing process that requires a processing step using a process gas in a sealed chamber.

A semiconductor manufacturing apparatus according to the present invention has a fluid control device that supplies a process gas to a processing chamber,
The fluid control device includes a plurality of fluid devices,
The fluid device includes the solenoid valve described above.

ADVANTAGE OF THE INVENTION According to this invention, the sealing performance at the time of valve closing of a solenoid valve can be improved.
Also, according to the present invention, a solenoid valve suitable for a flow control device is provided.

1 is a cross-sectional view of a flow control device to which a solenoid valve according to an embodiment of the invention is applied; FIG. FIG. 2 is an enlarged cross-sectional view around the valve seat of the flow control device of FIG. 1; The figure which shows the cross-sectional structure of the valve seat in the circle A of FIG. 2A. The front view of a valve body. A bottom view showing only the facing surface of the valve body of FIG. 3A. FIG. 3B is a cross-sectional view around the annular groove taken along line 4A-4A in FIG. 3B; Enlarged view of circle B showing the structure of the annular groove. Sectional drawing which shows the relationship between a valve seat and an annular groove. Schematic diagram for explaining the guide function of the valve seat and the annular groove. FIG. 6B is a schematic diagram showing a valve closed state following FIG. 6A; 1 is a perspective view showing an example of a fluid control device to which the solenoid valve or flow control device of this embodiment is applied; FIG. 1 is a schematic diagram showing an application example of a fluid control device according to an embodiment of the present invention to a semiconductor manufacturing process; FIG.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the description, the same reference numerals are given to the same elements, and overlapping descriptions are omitted as appropriate.
FIG. 1 shows a flow control device 1 to which a solenoid valve according to one embodiment of the invention is applied. In FIG. 1, a cover that covers the entire flow control device 1, a control board that controls the flow control device 1, a temperature sensor, and the like actually exist, but they are omitted. In FIG. 1, A1 and A2 indicate the vertical direction, with A1 indicating the upward direction and A2 indicating the downward direction.
The flow control device 1 includes an upstream block 24, a valve body 16, a downstream block 25, an orifice 19, a valve body 20, a leaf spring 43, a movable stem 55, a bellows 30, a solenoid actuator 50, an adjusting member 60, and a lock nut. 61.

A concave valve chamber 16d is formed in the upper portion of the valve body 16, and the flow passages 16a and 16b are connected to the valve chamber 16d. The channel 16a is connected to a channel 24a formed in the upstream block. The flow path 16b communicates with a flow path 16c extending horizontally in the valve body 16. The flow path 16c is connected to a flow path 25a formed in a downstream block 25 and an orifice 19 (a gasket type orifice in this embodiment). connected through
The flow path 16b of the valve body 16 opens at the bottom surface of the valve chamber 16d, and an annular valve seat 17 is formed integrally with the valve body 16 around this opening. The structure of the valve seat 17 will be detailed later.

The valve body 20 is formed in a disc shape, is arranged to face the valve seat 17 , and is always biased toward the valve seat 17 by a leaf spring 43 . The leaf spring 43 is sandwiched between an annular member 42 provided at the lower end of the casing 51 of the solenoid actuator 50 and a nut member 41 screwed on the outer periphery thereof. The structure of the valve body 20 will be detailed later.

The solenoid actuator 50 is a well-known actuator in which a plug nut (fixed iron core), a coil, a yoke, a sleeve, etc., and a movable stem 55 as a movable iron core (not shown) are incorporated in a casing 51 . By applying an electric current to this coil, the plug nut and the movable stem 55 are magnetized, and the movable stem 55 is lifted upward A1 against the biasing force of the plate spring 43 by the magnetic force. As a result, the channel 16b is opened and communicated with the channel 16a. By controlling the magnetic force according to the voltage applied to the coil, the amount of lift of the valve body 20 from the valve seat 17 can be controlled, and the flow rate of the fluid flowing from the flow path 16a to the flow path 16b can be controlled.
A base end portion 51b of the casing 51 is fixed to the upper surface of the valve body 16 by a fastening member BT, thereby hermetically closing the valve chamber 16d of the valve body 16 . The bellows 30 is provided to prevent the fluid inside the valve chamber 16 d from entering the casing 51 .
Thus, the valve body 16 and the solenoid actuator 50 constitute a solenoid valve.
An adjustment member 60 for adjusting the lift amount of the movable stem 55 is provided at the upper end of the solenoid actuator 50 . By rotating the adjusting member 60, the positions of the plug nuts in the vertical directions A1 and A2 are adjusted. A lock nut 61 is provided to lock the position of the adjustment member 60 .

Pressure sensors 70 and 71 are provided upstream and downstream of the orifice 19 of the flow control device 1, respectively. In the flow control device 1, the solenoid valve is feedback-controlled based on the pressure in the flow path detected by the two pressure sensors 70 and 71 so that the flow rate of the fluid flowing out of the flow path 25a becomes the target flow rate. be.

Structure of Valve Seat The structure of the valve seat 17 is shown in FIGS. 2A and 2B. 2B is an enlarged view of the circle A in FIG. 2A (hatching is omitted).
The valve seat 17 is annularly formed around the opening of the flow path 16 b and protrudes from the upper end surface 16 f of the valve body 16 .
The hardness of the valve seat 17 is Hv300 or higher. The valve body 16 is made of a metal such as stainless steel and has a hardness of about Hv200, while the valve seat 17 is partially hardened by work hardening.
As can be seen from FIG. 2B, the valve seat 17 has a sealing surface 17a at its upper end, which is a convexly curved curved surface. Specifically, the seal surface 17a is an arcuate curved surface with a radius of curvature R1. In addition, the sealing surface 17a is not limited to an arc-shaped curved surface.
The valve seat 17 further has an inclined surface 17b that continues on the outer peripheral side of the sealing surface 17a and that is inclined to widen toward the root portion of the valve seat, that is, the upper end surface 16f of the valve body 16. As shown in FIG. This inclined surface 17b is smoothly connected to the sealing surface 17a, and is inclined at an angle α with respect to the direction perpendicular to the upper end surface 16f. It is not limited to this.

Valve Body Structure The structure of the valve body 20 is shown in FIGS. 3A and 3B.
The valve body 20 faces a disk portion 20d formed in a disk shape, a shaft portion 20s provided in the center of the upper surface side of the disk portion 20d, and a valve seat 17 formed on the lower surface side of the disk portion 20d. and a facing surface 20f.
The valve body 20 is fixed to the movable stem 55 by screwing the shaft portion 20 s into the lower end portion of the movable stem 55 .
20 f of opposing surfaces consist of flat surfaces, and as shown to FIG. 3B, the annular groove 21 is formed in the center part of 20 f of opposing surfaces. In addition, in the present embodiment, the facing surface 20f is a flat surface, but the present invention is not limited to this.
The valve body 20 is made of a metal material such as a stainless alloy, and has a hardness lower than that of the valve seat 17, for example, a hardness within the range of Hv100 to Hv140. The reason why the hardness of the valve body 20 is lower than that of the valve seat 17 is that the valve body 20 is plastically deformed to form the annular groove 21, as will be described later.

4A and 4B show the structure of the annular groove.
As shown in FIG. 4A, the annular groove 21 is an annular depression formed in the facing surface 20f, and has a concave curved surface 21a as shown in FIG. 4B. Specifically, the curved surface 21a is an arc-shaped curved surface having a curvature radius R2, and the curvature radius R2 substantially matches the curvature radius R1 of the seal surface 17a of the valve seat 17 described above. That is, the curved surface 21a has a shape whose radius of curvature R2 matches the sealing surface 17a of the valve seat 17 described above.
On the outer peripheral side of the curved surface 21a, an inclined surface portion 21b that widens toward the opposing surface 20f is formed. have In the present embodiment, the inclined surface 17b and the inclined surface portion 21b are configured to extend linearly when viewed in cross section, but are not limited to this and may be curved.

An example of a method for processing the annular groove 21 will be described.
When the flow control device 1 (solenoid valve) is assembled, the annular groove 21 is not yet formed on the facing surface 20f of the valve body 20. As shown in FIG.
Therefore, the adjustment member 60 provided at the upper end of the solenoid actuator 50 is rotated to press the facing surface 20 f of the valve body 20 against the valve seat 17 . A necessary torque is applied to the adjustment member 60 to cause plastic deformation of the facing surface 20 f of the valve body 20 . The opposing surface 20 f of the valve body 20 is pressed against the valve seat 17 until the upper portion of the inclined surface 17 b of the valve seat 17 bites into the opposing surface 20 f of the valve body 20 .
In this embodiment, the adjustment member 60 for adjusting the lift amount of the valve body 20 is used for machining the annular groove 21, but a separate mechanism may be provided for machining the annular groove 21, or a dedicated mechanism may be provided. It is also possible to apply an external force to the valve body 20 from the outside using a tool or the like.

As shown in FIG. 5, the central axis Ct1 of the annular groove 21 and the central axis Ct2 of the valve seat 17 are designed to coincide, and the valve seat 17 and the annular groove 21 are positioned at corresponding positions. In this embodiment, the contact area between the valve seat 17 and the valve body 20 is provided with a convex curved seal surface 17a and a concave curved surface 21a matching the seal surface 17a, thereby increasing the contact area and sealing. We are working to improve performance. In addition, by providing a difference in hardness between the valve seat 17 and the valve body 20, the contact portion between the two can easily conform to each other, further enhancing the sealing performance.
However, if the central axis Ct1 and the central axis Ct2 are always aligned when the valve is repeatedly opened and closed, the contact position of the annular groove 21 with respect to the valve seat 17 will always be the same. Although it can be maintained, a slight deviation always occurs between the center axis Ct1 of the annular groove 21 and the center axis Ct2 of the valve seat 17 as shown in FIG.

In this embodiment, the contact portion between the valve seat 17 and the valve body 20 is provided with a seal surface 17a consisting of a convex curved surface and a concave curved surface 21a matching the sealing surface 17a. The surface 17b and the annular groove 21 are provided with corresponding inclined surface portions 21b.
Therefore, as shown in FIG. 6B, the inclined surface 17b and the annular groove 21 perform a guide function, and when the valve seat 17 and the valve body 20 come into contact with each other, the central axis Ct1 of the annular groove 21 and the center of the valve seat 17 are aligned. The deviation from the axis Ct2 is canceled. As a result, a high sealing performance is always maintained when the valve is closed.

An example of a fluid control device to which the solenoid valve or flow control device 1 of the present invention is applied will be described with reference to FIG.
The fluid control device shown in FIG. 7 is provided with metal base plates BS arranged along width directions W1 and W2 and extending in longitudinal directions G1 and G2. W1 indicates the front side, W2 indicates the rear side, G1 indicates the upstream side, and G2 indicates the downstream side. Various fluid devices 991A to 991E are installed on the base plate BS via a plurality of flow path blocks 992, and a flow path (not shown) through which the fluid flows from the upstream side G1 to the downstream side G2 through the plurality of flow path blocks 992. are formed respectively.

Here, the term “fluid device” refers to a device used in a fluid control device for controlling the flow of fluid, comprising a body defining a fluid flow path, and having at least two flow path openings on the surface of the body. It is a device that has Specifically, an on-off valve (two-way valve) 991A, a regulator 991B, a pressure gauge 991C, an on-off valve (three-way valve) 991D, a mass flow controller 991E, etc. are included, but are not limited to these. The introduction pipe 993 is connected to the upstream side port of the flow path (not shown).

The flow control device 1 according to this embodiment can be used as the mass flow controller 991E described above. Also, the solenoid valve according to the present embodiment can be applied to valves such as an on-off valve (two-way valve) 991A, a regulator 991B, a pressure gauge 991C, and an on-off valve (three-way valve) 991D.

Next, FIG. 8 shows an example of a semiconductor manufacturing apparatus to which the fluid control device described above is applied.
A semiconductor manufacturing apparatus 1000 is a system for executing a semiconductor manufacturing process by an atomic layer deposition method (ALD), 600 is a process gas supply source, 700 is a fluid control device, 710 is a tank, and 800 is a Processing chamber, 900 shows the exhaust pump.
In the process of depositing a film on a substrate, the processing gas supplied from the flow control device 700 is temporarily stored in a tank 710 as a buffer in order to stably supply the processing gas. The provided valve 720 is frequently opened and closed to supply the processing gas from the tank 700 to the processing chamber 800 in the vacuum atmosphere.
The ALD method is one of the chemical vapor deposition methods, and under film formation conditions such as temperature and time, two or more types of processing gases are alternately flowed onto the substrate surface one by one to form atoms on the substrate surface. It is a method of depositing a film by single layer by reaction, and since it is possible to control each single atomic layer, it is possible to form a uniform film thickness, and it is possible to grow a very dense film in terms of film quality. .
In the semiconductor manufacturing process by the ALD method, it is necessary to precisely adjust the flow rate of the processing gas, and it is also necessary to secure the flow rate of the processing gas to some extent by increasing the diameter of the substrate.
The fluid control device 700 provides precisely metered process gases to the processing chamber 800 . The fluid control device 700 includes the flow control device 1 described above.
The tank 710 functions as a buffer that temporarily stores the processing gas supplied from the fluid control device 700 .
Processing chamber 800 provides an enclosed processing space for deposition of films on substrates by ALD methods.
The exhaust pump 900 evacuates the inside of the processing chamber 800 .

In addition, this invention is not limited to embodiment mentioned above. Those skilled in the art can make various additions, modifications, etc. within the scope of the present invention. For example, in the application example described above, the case where the flow control device 1 is used in a semiconductor manufacturing process by the ALD method is illustrated, but the present invention is not limited to this, and the present invention is applicable to, for example, an atomic layer etching method (ALE). It can be applied to any object that requires precise flow rate adjustment, such as the law).
Further, in the present embodiment, the valve seat has higher hardness than the valve body, and the convex seal surface is provided on the valve seat and the annular groove is provided on the flat surface of the valve body. The valve body may be provided with a convex annular sealing surface and the valve seat may be provided with an annular groove.

Reference Signs List 1: flow control device 16: valve body 16a: flow path 16b: flow path 16c: flow path 16d: valve chamber 16f: upper end surface 17: valve seat 17a: sealing surface 17b: inclined surface 19: orifice 20: valve element 20d: Disk portion 20f: facing surface 20s: shaft portion 21: annular groove 21a: curved surface 21b: inclined surface portion 24: upstream block 24a: flow path 25: downstream block 25a: flow path 30: bellows 41: nut member 42: annular Member 43 : Leaf spring 50 : Solenoid actuator 51 : Casing 51 b : Base end 55 : Movable stem 60 : Adjusting member 61 : Lock nuts 70 and 71 : Pressure sensor 600 : Process gas supply source 700 : Fluid control device 710 : Tank 720 : Valve 800 : Processing chamber 900 : Exhaust pump 991A : Open/close valve (two-way valve)
991B: regulator 991C: pressure gauge 991D: on-off valve (three-way valve)
991E: mass flow controller 992: flow path block 993: introduction pipe 1000: semiconductor manufacturing apparatus A: circle A1: upward direction A2: downward direction BS: base plate BT: fastening member Ct1: center axis line Ct2: center axis line G1: longitudinal direction (upstream side)
G2: Longitudinal direction (downstream side)
R1: Radius of curvature R2: Radius of curvature W1: Width direction (front side)
W2: Width direction (back side)
α : Angle

Claims (11)

A solenoid valve having a metal alloy ring-shaped valve seat, a metal alloy valve body provided to be in contact with and separated from the valve seat, and a solenoid actuator for driving the valve body, the solenoid valve comprising: ,
either the valve body or the valve seat has a sealing surface with a convex curved surface;
the other of the valve body and the valve seat has an annular groove facing the sealing surface and having a concavely curved surface that matches the curved surface of the sealing surface;
A difference in hardness is provided between the contact portion of the valve body and the valve seat, and the sealing surface is formed to have a hardness higher than that of the annular groove,
The sealing surface further has an inclined surface that continues on the outer peripheral side of the curved surface and that is inclined so as to widen toward the root portion of the valve seat,
The solenoid valve, wherein the annular groove further has a ramp portion that matches a portion of the ramp. A solenoid valve having a metal alloy ring-shaped valve seat, a metal alloy valve body provided to be in contact with and separated from the valve seat, and a solenoid actuator for driving the valve body, the solenoid valve comprising: ,
either the valve body or the valve seat has a sealing surface with a convex curved surface;
the other of the valve body and the valve seat has an annular groove facing the sealing surface and having a concavely curved surface that matches the curved surface of the sealing surface;
A difference in hardness is provided between the contact portion of the valve body and the valve seat, and the sealing surface is formed to have a hardness higher than that of the annular groove,
The sealing surface is provided on the valve seat,
A solenoid valve, wherein the annular groove is provided in a valve body. A solenoid valve having a metal alloy ring-shaped valve seat, a metal alloy valve body provided to be in contact with and separated from the valve seat, and a solenoid actuator for driving the valve body, the solenoid valve comprising: ,
either the valve body or the valve seat has a sealing surface with a convex curved surface;
the other of the valve body and the valve seat has an annular groove facing the sealing surface and having a concavely curved surface that matches the curved surface of the sealing surface;
A difference in hardness is provided between the contact portion of the valve body and the valve seat, and the sealing surface is formed to have a hardness higher than that of the annular groove,
The hardness of the valve seat is Hv300 or more,
A solenoid valve, wherein hardness of at least a portion of the valve body that contacts the valve seat is within a range of Hv100 to Hv140. 4. The solenoid valve according to any one of claims 1 to 3, wherein said sealing surface has an arc-shaped curved surface. further comprising a valve body defining a flow path;
5. Any one of claims 1 to 4, wherein the valve seat is integrally formed around the opening of the flow path of the valve body, and is formed to have a higher hardness than portions other than the valve seat. Solenoid valve as described. A method for manufacturing a solenoid valve,
The solenoid valve has an annular valve seat made of a metal alloy, a valve body made of a metal alloy provided to be able to contact and separate from the valve seat, and a solenoid actuator that drives the valve body. A solenoid valve,
either the valve body or the valve seat has a sealing surface with a convex curved surface;
the other of the valve body and the valve seat has an annular groove facing the sealing surface and having a concavely curved surface that matches the curved surface of the sealing surface;
A solenoid valve in which a difference in hardness is provided in a contact portion between the valve body and the valve seat, and the sealing surface is formed to have a hardness higher than that of the annular groove,
The method of manufacturing a solenoid valve includes pressing the valve body against the valve seat to cause plastic deformation in the valve body to form the annular groove. A flow control device incorporating the solenoid valve according to any one of claims 1 to 5 as a flow control valve. A flow rate control method, comprising controlling the flow rate of a fluid using the solenoid valve according to any one of claims 1 to 5. A fluid control device in which a plurality of fluid devices are arranged,
A fluid control device, wherein the plurality of fluid devices includes the solenoid valve according to any one of claims 1 to 5 or the flow control device according to claim 7 . 6. A semiconductor manufacturing method, wherein the solenoid valve according to any one of claims 1 to 5 is used to control the flow rate of the process gas in a semiconductor device manufacturing process that requires a treatment step with a process gas in a sealed chamber. having a fluid controller for supplying process gas to the processing chamber;
The fluid control device includes a plurality of fluid devices,
A semiconductor manufacturing apparatus, wherein the fluid device includes the solenoid valve according to any one of claims 1 to 5.

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