Pressure Control Valve

Abstract

To provide a pressure control valve that prevents process gas from cooling during vacuum chamber evacuation and prevents particle generation.SOLUTION: A pressure control valve 1 that opens and closes a circular exhaust port 15 connecting a vacuum chamber 2 used for semiconductor manufacturing equipment and an exhaust pump 3 that exhausts the vacuum chamber 2, has a valve plug 11 that contacts and separates from a valve seat 12 provided radially outward from the exhaust port 15. The valve plug 11 has a hollow section 17 located between an upper surface 11a on the vacuum chamber 2 side of the valve plug 11 and a lower surface 11b on the exhaust pump 3 side of the valve plug 11, a first rubber heater 23 covering a first back surface 18a of the upper surface 11a in the hollow section 17, and a second rubber heater 24 covering a second back surface 19a of the lower surface 11b in the hollow section 17.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a pressure control valve that opens and closes a circular opening that connects a vacuum chamber used in a semiconductor manufacturing device to an exhaust pump that evacuates the vacuum chamber. [Background technology]

[0002] In semiconductor manufacturing equipment, surface treatment (etching, etc.) of a wafer is performed by placing the wafer in a vacuum chamber and introducing various process gases into the vacuum chamber. The vacuum chamber is connected to an exhaust pump via an exhaust port, and the process gas introduced into the vacuum chamber is sucked in by the exhaust pump and exhausted from the exhaust port. The exhaust port is provided with a pressure control valve for opening and closing the exhaust port, and the amount of exhaust from the exhaust port can be adjusted by adjusting the opening of the pressure control valve. This makes it possible to adjust the pressure inside the vacuum chamber. As an example of a pressure control valve, a main valve disclosed in Patent Document 1 is known. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-42734 Summary of the Invention [Problem to be solved by the invention]

[0004] The process gas introduced into the vacuum chamber is heated to a high temperature of, for example, about 100°C, but when it is exhausted from the vacuum chamber, it is cooled by contacting the valve body of the pressure control valve, and there is a risk that the components of the process gas will accumulate on the surface of the valve body. If the components of the process gas accumulate on the surface of the valve body, they will fly up as particles during the surface treatment of the wafer, and there is a risk that they will cause defects in the surface treatment.

[0005] The present invention has been made in consideration of the above problems, and has an object to provide a pressure control valve that can prevent the process gas from being cooled when the vacuum chamber is evacuated, and can prevent the generation of particles. [Means for solving the problem]

[0006] In order to solve the above problems, a pressure control valve according to one aspect of the present invention has the following configuration.

[0007] (1) A vacuum chamber used in semiconductor manufacturing equipment and an exhaust port that evacuates the vacuum chamber In a pressure control valve that opens and closes a circular opening that connects a pump and a The valve body is provided with a valve seat provided radially outward and in contact with and spaced from the valve seat, between the upper surface of the valve body on the side of the vacuum chamber and the lower surface of the valve body on the side of the exhaust pump. a first planar heater covering a first back surface of the upper surface in the hollow portion; and a second planar heater covering the second back surface of the lower surface. the entire upper surface and the entire lower surface are uniformly heated when the vacuum chamber is evacuated; It is characterized by:

[0008] According to the pressure control valve described in (1), the valve body has a hollow portion located between the upper surface of the valve body on the vacuum chamber side and the lower surface of the valve body on the exhaust pump side, thereby reducing the heat capacity. In addition, the valve body is provided with a first planar heater that covers the back surface of the upper surface in the hollow portion, and a second planar heater that covers the back surface of the lower surface in the hollow portion, so that the entire upper surface and the entire lower surface of the valve body can be heated evenly.

[0009] Since the process gas mainly comes into contact with the upper and lower surfaces of the valve body when the vacuum chamber is evacuated, if it is possible to heat the entire upper and lower surfaces of the valve body evenly, the process gas can be prevented from being cooled by the valve body. This makes it possible to prevent components of the process gas from accumulating on the surface of the valve body, and in turn reduces the risk of the accumulated components flying up as particles and causing defects in the surface processing of the wafer.

[0010] Conventionally, it has been known that process gas components deposited on the upper surface (i.e., the upstream surface) of the valve disc may fly up into the vacuum chamber as particles, but it was not thought that process gas components deposited on the lower surface (i.e., the downstream surface) of the valve disc would fly up into the vacuum chamber because they would flow together with the process gas during exhaust. However, the inventors of the present application believed that process gas components deposited on the lower surface would fly up into the vacuum chamber as particles, and therefore in the pressure control valve described in (1), not only the upper surface but also the lower surface of the valve disc is heated by a planar heater to prevent particle generation.

[0011] (2) In the pressure control valve described in (1), the thickness from the upper surface to the first back surface and the thickness from the lower surface to the second back surface are 4 mm or more and 8 mm or less.

[0012] The thinner the thickness from the top surface to the first back surface and the thickness from the bottom surface to the second back surface, the smaller the heat capacity of the valve body, making it easier to heat with the first and second planar heaters. On the other hand, the strength of the valve body decreases. Therefore, it is important to balance the heat capacity and strength. The inventors of the present application have confirmed through experiments that a balance between heat capacity and strength can be achieved by setting the thickness from the top surface to the first back surface and the thickness from the bottom surface to the second back surface to 4 mm or more and 8 mm or less, as in the pressure control valve described in (2).

[0013] (3) In the pressure control valve described in (1) or (2), the valve body has an annular seal portion that abuts against and separates from the valve seat, and the hollow portion is located on the radially inner side of the annular seal portion.

[0014] A valve body with a hollow portion has a lower strength than a solid valve body. For this reason, for example, if the hollow portion of the valve body is provided on the back side of the annular seal portion, when the annular seal portion abuts against the valve seat, the valve body may bend, and the force pressing the annular seal portion against the valve seat 12 may be absorbed. According to the pressure control valve described in (3), since the hollow portion is located on the radially inner side of the annular seal portion, the back side of the annular seal portion of the valve body is solid, and the valve body can be prevented from bending. This makes it possible to prevent the force pressing the annular seal portion against the valve seat from being absorbed.

[0015] (4) The pressure control valve according to any one of (1) to (3), wherein a cooling gas supply passage capable of supplying a cooling gas is connected to the hollow portion.

[0016] Depending on the type of process gas, the temperature conditions for the surface treatment of the wafer differ, and it may be necessary to lower the temperature of the valve body of the pressure control valve. Conventionally, it was necessary to wait for the temperature of the valve body to drop naturally, and there was a concern that the efficiency of the wafer surface treatment process would decrease. According to the pressure control valve described in (4), since the cooling gas supply path capable of supplying the cooling gas is connected to the hollow portion, it is possible to quickly lower the temperature of the valve body by supplying the cooling gas to the hollow portion. Effect of the Invention

[0017] According to the pressure control valve of the present invention, it is possible to prevent the process gas from being cooled when the vacuum chamber is evacuated, and to prevent the generation of particles. [Brief description of the drawings]

[0018] [Figure 1]1 is a schematic diagram of a semiconductor manufacturing apparatus for performing surface treatment on a wafer; [Diagram 2] FIG. 1 is a perspective view of a pressure control valve according to a first embodiment. [Diagram 3] 1 is a partial cross-sectional view of a pressure control valve according to a first embodiment. [Figure 4] FIG. 4 is a partially enlarged view of a portion A in FIG. [Diagram 5] 11 is a partial enlarged view of the valve body immediately after it starts to move from the closed position to the open position. FIG. [Figure 6] 13 is a diagram showing the configuration of a valve body of a pressure control valve according to a second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] (First embodiment) A first embodiment of a pressure control valve according to the present invention will be described in detail with reference to the drawings.

[0020] FIG. 1 is a schematic diagram of a semiconductor manufacturing apparatus for performing surface treatment of a wafer. FIG. 2 is a perspective view of a pressure control valve 1 according to a first embodiment. FIG. 3 is a partial cross-sectional view of the pressure control valve 1 according to this embodiment. Note that the arrows in the figure indicate the flow of process gas during exhaust. FIG. 4 is a partial enlarged view of part A in FIG. 3.

[0021] As shown in FIG. 1, the semiconductor manufacturing equipment includes a pressure control valve 1, a vacuum chamber 2, an exhaust pump 3, a process controller 4, a gas supply source 5, a mass flow controller (MFC) 6, pressure gauges 7 and 8, and a valve controller 9.

[0022] A wafer to be surface-treated is placed inside the vacuum chamber 2. A gas supply source 5 is a supply source of a process gas used for the surface treatment of the wafer. The process gas output from the gas supply source 5 is flow-regulated by an MFC 6 and then introduced into the vacuum chamber 2.

[0023] Pressure gauges 7 and 8 measure the pressure inside the vacuum chamber 2. The process controller 4 is electrically connected to the gas supply source 5, MFC 6, and pressure gauge 7. As a result, the process controller 4 monitors the pressure value measured by the pressure gauge 7, while controlling the ON / OFF of the process gas output from the gas supply source 5 and adjusting the flow rate of the process gas by the MFC 6.

[0024] 3, a circular exhaust port 15 (an example of an opening) is formed penetrating the bottom surface of the vacuum chamber 2. In addition, near the outer periphery of the exhaust port 15 in the radial direction of the bottom surface of the vacuum chamber 2, is a valve seat 12 with which a valve body 11 (described later) comes into contact and separates.

[0025] The vacuum chamber 2 is connected to an exhaust pump 3 via an exhaust port 15. When the exhaust pump 3 operates, the process gas introduced into the vacuum chamber 2 can be exhausted from the exhaust port 15.

[0026] The pressure control valve 1 is a valve for controlling the pressure inside the vacuum chamber 2 by adjusting the amount of process gas exhausted from the exhaust port 15. The pressure control valve 1 is electrically connected to a valve controller 9, and a pressure gauge 8 is further electrically connected to the valve controller 9. As a result, the valve controller 9 adjusts the opening of the pressure control valve 1 while monitoring the pressure value measured by the pressure gauge 7 so that the pressure value inside the vacuum chamber 2 becomes an optimum pressure for performing surface treatment.

[0027] 2 and 3, the pressure control valve 1 includes a valve body 11 and a pair of actuators 13. The pair of actuators 13 are disposed radially outside an exhaust port 15, sandwiching the exhaust pump 3 therebetween. Rods 14, which are driven in the penetrating direction of the exhaust port 15 (the up and down direction in the figure), extend from each of the pair of actuators 13 into the vacuum chamber 2. Note that since the rods 14, are covered by, for example, bellows (not shown), the inside and outside of the vacuum chamber 2 are not connected at the points where the rods 14 are inserted.

[0028] The valve body 11 is fixed to the tip of the rods 14, 14 in the vacuum chamber 2 so as to bridge the rods 14, 14. As a result, by driving the rods 14, 14, the valve body 11 can be moved steplessly between a closed position where the exhaust port 15 is blocked and an open position where the exhaust port 15 is opened along the vertical direction in the figure. In other words, the valve controller 9 can adjust the opening degree of the valve body 11 steplessly by adjusting the driving amount of the rods 14, 14. The stroke between the closed position and the open position is not particularly limited, but is about 100 mm in this embodiment. Also, the pressure control valve 1 shown in Figures 2 and 3 shows a state in which the valve body 11 is in the open position.

[0029] The valve body 11 comprises a main body member 20, a pair of support members 16, 16 that support the main body member 20, a disk-shaped upper plate 18 that forms the upper surface 11a of the valve body 11, a disk-shaped lower plate 19 that forms the lower surface 11b of the valve body 11, a valve body block 21, an O-ring 22 (an example of an annular seal portion), a first rubber heater 23 (an example of a first planar heater), and a second rubber heater 24 (an example of a second planar heater).

[0030] The main body member 20 is made of an aluminum alloy and is formed into a cylindrical shape with an open top and bottom. A flat portion 20e is cut out on the inner peripheral surface of the main body member 20, in a portion facing the support member 16, so that a flange portion 20c remains at the lower end of the main body member 20.

[0031] The support members 16, 16 are made of an aluminum alloy and are formed to a thickness of about 30 mm. The end of the support member 16 opposite to the main body member 20 side is connected to the rod 14. The end of the support member 16 on the main body member 20 side is abutted against the flat surface portion 20e of the main body member 20. The support member 16 is fastened to the main body member 20 by a bolt 25 (see FIG. 2) that is screwed in perpendicularly to the flat surface portion 20e. In this way, the pair of support members 16, 16 support the main body member 20 so that it is positioned coaxially with the exhaust port 15. Although only one bolt 25 is visible in FIG. 2, two bolts 25 are used for one support member 16.

[0032] Further, an upper step portion 16d is formed in the support members 16, 16 on the upper surface 11a side of the end portion on the main body member 20 side (see FIG. 4). The depth of the upper step portion 16d is approximately the same as the thickness of the upper plate 18. Furthermore, an inner surface 16f of the upper step portion 16d facing the main body member 20 side is an arc-shaped surface having a radius approximately the same as the outer diameter of the disk-shaped upper plate 18. Further, a lower step portion 16e is formed in the support member 16 on the lower surface 11b side of the end portion on the main body member 20 side (see FIG. 4). The depth of the lower step portion 16e is approximately the same as the thickness of the flange portion 20c of the main body member 20. Furthermore, an inner surface 16g of the lower step portion 16e facing the main body member 20 side is an arc-shaped surface having a radius approximately the same as the outer diameter of the main body member 20 (flange portion 20c). When the support member 16 is fastened to the main body member 20, the flange portion 20c of the main body member 20 is positioned within the lower step portion 16e of the support member 16, and the lower surface of the main body member 20 and the lower surface of the support member 16 form the same plane.

[0033] The upper plate 18 is made of an aluminum alloy and is formed in a disk shape with a thickness of about 5 mm. The outer diameter of the upper plate 18 is approximately the same as the outer diameter of the main body member 20. The upper plate 18 is fixed to the end face of the main body member 20 on the upper surface 11a side by a bolt 26 (see FIG. 2). As a result, the upper plate 18 is positioned coaxially with the main body member 20 and closes the upper opening of the main body member 20. In addition, the upper plate 18 is positioned within the upper step portion 16d of the support member 16 in a state where it is fixed to the main body member 20, and the upper surface of the upper plate 18 and the upper surface of the support member 16 form the same plane. The upper plate 18 may be surface-treated, such as anodized.

[0034] The lower plate 19 is made of an aluminum alloy and is formed in a disk shape with a thickness of about 5 mm. The outer diameter of the lower plate 19 is approximately the same as the outer diameter of the main body member 20. The lower plate 19 is fixed to the end face of the main body member 20 on the lower surface 11b side. As a result, the lower plate 19 is positioned coaxially with the main body member 20 and closes the lower opening of the main body member 20. The lower plate 19 may be surface-treated, such as anodized.

[0035] The upper plate 18 blocks the upper opening of the main body member 20, and the lower plate 19 blocks the lower opening of the main body member 20, so that a hollow portion 17 is formed in the valve body 11 as a space surrounded by the back surface 18a (first back surface) of the upper plate 18, the inner surface 20d of the main body member 20, and the back surface 19a (second back surface) of the lower plate 19.

[0036] A first rubber heater 23 and a second rubber heater 24 are disposed in the hollow portion 17. The first rubber heater 23 is formed in a disk shape. Its diameter is smaller than the inner diameter of the main body member 20, but is large enough to cover the part exposed in the hollow portion 17 of the back surface 18a of the upper plate 18. The first rubber heater 23 is bonded to the back surface 18a of the upper plate 18, and is capable of heating the upper plate 18. The second rubber heater 24 is a heater similar to the first rubber heater 23, and is formed in a disk shape. Its diameter is smaller than the inner diameter of the main body member 20, but is large enough to cover the part exposed in the hollow portion 17 of the back surface 19a of the lower plate 19. The second rubber heater 24 is bonded to the back surface 19a of the lower plate 19, and is capable of heating the lower plate 19.

[0037] Wiring paths 16b and 20a are connected to the hollow portion 17, and for example, an electric wire passing through the inside of the rod 14 can be passed through the wiring paths 6b and 20a and extended to the hollow portion 17. This allows the first rubber heater 23 and the second rubber heater 24 to be electrically connected to the valve controller 9. The first rubber heater 23 and the second rubber heater 24 are temperature controlled by the valve controller 9. The first rubber heater 23 and the second rubber heater 24 heat the upper plate 18 and the lower plate 19 to a temperature (e.g., 120°C) at which the process gas introduced into the vacuum chamber 2 does not liquefy when it comes into contact with the valve body 11 (upper plate 18, lower plate 19).

[0038] The valve body 11 has a small heat capacity due to the hollow portion 17. In addition, since the valve body 11 is provided with the first rubber heater 23 covering the back surface 18a and the second rubber heater 24 covering the back surface 19a, it is possible to heat the entire upper surface 11a and the entire lower surface 11b of the valve body 11 evenly.

[0039] When the vacuum chamber 2 is evacuated, the process gas mainly comes into contact with the upper surface 11a and the lower surface 11b of the valve body 11, so if it is possible to heat the entire upper surface 11a and the entire lower surface 11b of the valve body 11 evenly, it is possible to prevent the process gas from being cooled by the valve body 11. This makes it possible to prevent components of the process gas from accumulating on the surface of the valve body 11, and in turn reduces the risk of the accumulated components flying up as particles and causing defects in the surface processing of the wafer.

[0040] Note that the thickness of the upper plate 18 and the lower plate 19 being 5 mm is merely an example. The thinner the upper plate 18 and the lower plate 19, the smaller the heat capacity of the valve body 11, making it easier to heat it with the first rubber heater 23 and the second rubber heater 24. On the other hand, the strength of the valve body 11 decreases. Therefore, it is important to balance the heat capacity and strength. Therefore, it is desirable to set the thickness of the upper plate 18 and the lower plate 19 in the range of 4 mm or more and 8 mm or less.

[0041] Of the surface of the lower plate 19 that forms the lower surface 11b, a first annular groove 19b is formed coaxially with the exhaust port 15 in a portion that faces the valve seat 12. An O-ring 22 (an example of an annular seal portion) is fitted into this first groove 19b. The closed position of the valve body 11 is a position where the O-ring 22 abuts against the valve seat 12. When the O-ring 22 abuts against the valve seat 12, the elastic force of the O-ring 22 can keep the inside of the vacuum chamber 2 airtight.

[0042] Here, the hollow portion 17 is located on the radially inner periphery side of the O-ring 22. Specifically, the diameter of the hollow portion 17 (i.e., the inner diameter of the main body member 20) is smaller than the diameter of the O-ring 22. In other words, since the portion of the valve body 11 where the O-ring 22 is attached is solid, the valve body 11 is prevented from being deflected by the elastic force of the O-ring 22 when the valve body 11 is in the closed position.

[0043] A ring-shaped second groove 19c is formed in the lower plate 19 on the radially inner side of the first groove 19b so as to be coaxial with the exhaust port 15. A valve block 21 is attached to this second groove 19c.

[0044] The valve block 21 is made of an aluminum alloy and has a cylindrical main body portion 21a that is open at the top and bottom, and a flange portion 21b that extends radially outward from the upper end portion of the main body portion 21a on the lower plate 19 side.

[0045] A first through hole (not shown) through which a screw can be inserted is provided in the flange portion 21b in the vertical direction in the figure. Furthermore, a second through hole (not shown) is provided in the lower plate 19 in the vertical direction in the figure, coaxially with the first through hole. By screwing a bolt inserted through the first through hole and the second through hole into the main body member 20, the valve block 21 is fixed to the second groove 19c and the lower plate 19 is fixed to the main body member 20. Note that the valve block 21 and the lower plate 19 may be fixed separately, for example, by fixing the valve block 21 to the lower plate 19 and fixing the lower plate 19 to the main body member 20.

[0046] With the valve body block 21 fixed, the main body 21a is positioned coaxially with the exhaust port 15. In addition, the outer diameter of the main body 21a is smaller than the exhaust port 15, and the main body 21a is inserted into the exhaust port 15 when the valve body 11 is in the closed position.

[0047] By inserting the main body 21a into the exhaust port 15, the valve block 21 prevents the pressure in the vacuum chamber 2 from fluctuating suddenly when the valve 11 starts to move from the closed position to the open position. To be more specific, if the valve 11 does not have the valve block 21, a flow path of the inner diameter of the exhaust port 15 is formed immediately after the valve 11 starts to move from the closed position to the open position, so that the process gas is rapidly exhausted and the pressure in the vacuum chamber 2 fluctuates suddenly. On the other hand, as shown in this embodiment, if the main body 21a of the valve block 21 is inserted into the exhaust port 15 when the valve 11 is in the closed position, as shown in FIG. 5, at the moment when the valve 11 starts to move from the closed position to the open position, only a flow path of the difference between the inner diameter of the exhaust port 15 and the outer diameter of the main body 21a is formed, so that the exhaust of the process gas starts slowly. Therefore, it is possible to prevent the pressure in the vacuum chamber 2 from fluctuating suddenly. When the valve body 11 moves from the closed position toward the open position by approximately 10 to 70 mm, the main body portion 21a comes out of the exhaust port 15, so that a flow path the diameter of the exhaust port 15 is ensured.

[0048] Since the valve body 11 includes the valve body block 21, it appears that the exhausted process gas does not come into contact with the lower surface 11b of the valve body 11, and therefore heating the lower plate 19 with the second rubber heater 24 does not seem to have the effect of preventing the accumulation of components of the process gas. Indeed, when the valve body 11 starts to move from the closed position and the main body portion 21a of the valve body block 21 is inserted into the exhaust port 15, the process gas is unlikely to come into contact with the lower surface 11b. However, after the main body portion 21a exits from the exhaust port 15, the process gas goes around the main body portion 21a and comes into contact with the lower surface 11b. Therefore, heating the lower plate 19 with the second rubber heater 24 has the effect of preventing the accumulation of components of the process gas.

[0049] As described above, according to the pressure control valve 1 according to the first embodiment, (1) A pressure control valve 1 that opens and closes a circular opening (exhaust port 15) that connects a vacuum chamber 2 used in a semiconductor manufacturing apparatus to an exhaust pump 3 that evacuates the vacuum chamber 2 is provided with a valve body 11 that abuts and separates from a valve seat 12 that is provided radially outward of the opening (exhaust port 15), and the valve body 11 is characterized in that it includes a hollow portion 17 located between an upper surface 11a of the valve body 11 on the vacuum chamber 2 side and a lower surface 11b of the valve body 11 on the exhaust pump 3 side, a first planar heater (first rubber heater 23) that covers a first back surface 18a of the upper surface 11a in the hollow portion 17, and a second planar heater (second rubber heater 24) that covers a second back surface 19a of the lower surface 11b in the hollow portion 17.

[0050] According to the pressure control valve 1 described in (1), the valve body 11 has a hollow portion 17 located between the upper surface 11a of the valve body 11 on the vacuum chamber 2 side and the lower surface 11b of the valve body 11 on the exhaust pump 3 side, thereby reducing the heat capacity. In addition, the valve body 11 is provided with a first planar heater (first rubber heater 23) covering the first back surface 18a of the upper surface 11a in the hollow portion 17, and a second planar heater (second rubber heater 24) covering the second back surface 19a of the lower surface 11b in the hollow portion 17, so that the entire upper surface 11a and the entire lower surface 11b of the valve body 11 can be heated evenly.

[0051] When the vacuum chamber 2 is evacuated, the process gas mainly comes into contact with the upper surface 11a and the lower surface 11b of the valve body 11, so if it is possible to heat the entire upper surface 11a and the entire lower surface 11b of the valve body 11 evenly, it is possible to prevent the process gas from being cooled by the valve body 11. This makes it possible to prevent components of the process gas from accumulating on the surface of the valve body 11, and in turn reduces the risk of the accumulated components flying up as particles and causing defects in the surface processing of the wafer.

[0052] Conventionally, it has been known that process gas components deposited on the upper surface 11a of the valve body 11 may fly up into the vacuum chamber 2 as particles, but it was not thought that process gas components deposited on the lower surface 11b of the valve body 11 would flow along with the process gas during exhaust and fly up into the vacuum chamber 2. However, the inventors of the present application thought that process gas components deposited on the lower surface would fly up into the vacuum chamber 2 as particles, and therefore in the pressure control valve 1 described in (1), not only the upper surface 11a of the valve body 11 but also the lower surface 11b are heated by sheet heaters (rubber heaters 23, 24) to prevent particle generation.

[0053] (2) The pressure control valve 1 described in (1) is characterized in that the thickness from the upper surface 11a to the first back surface 18a and the thickness from the lower surface 11b to the second back surface 19a are 4 mm or more and 8 mm or less.

[0054] The thinner the thickness from the upper surface 11a to the first back surface 18a and the thickness from the lower surface 11b to the second back surface 19a, the smaller the heat capacity of the valve body 11, making it easier to heat it with the first planar heater and the second planar heater (the first rubber heater 23 and the second rubber heater 24). On the other hand, the strength of the valve body 11 decreases. Therefore, it is important to balance the heat capacity and the strength. The inventors of the present application have confirmed through experiments that it is possible to balance the heat capacity and the strength by setting the thickness from the upper surface 11a to the first back surface 18a and the thickness from the lower surface 11b to the second back surface 19a to 4 mm or more and 8 mm or less, as in the pressure control valve 1 described in (2).

[0055] (3) In the pressure control valve 1 described in (1) or (2), the valve body 11 is characterized in that it has an annular seal portion (O-ring 22) that abuts against and separates from the valve seat 12, and the hollow portion 17 is located on the radially inner side of the annular seal portion (O-ring 22).

[0056] The valve body 11 with the hollow portion 17 has a lower strength than a solid valve body. For this reason, for example, if the hollow portion 17 of the valve body 11 is provided on the back side of the annular seal portion (O-ring 22), when the annular seal portion (O-ring 22) abuts against the valve seat 12, the valve body 11 may bend, and the force with which the annular seal portion (O-ring 22) is pressed against the valve seat 12 may be absorbed. According to the pressure control valve 1 described in (3), since the hollow portion 17 is located on the radially inner side of the annular seal portion (O-ring 22), the back side of the annular seal portion (O-ring 22) of the valve body 11 is solid, and the valve body 11 can be prevented from bending. This makes it possible to prevent the force with which the annular seal portion (O-ring 22) is pressed against the valve seat 12 from being absorbed.

[0057] Second embodiment Next, a second embodiment of a pressure control valve according to the present invention will be described with reference to Fig. 6. Fig. 6 is a diagram showing the configuration of a valve body 11 of a pressure control valve 1 according to the second embodiment.

[0058] In the pressure control valve 1 according to the second embodiment, the wiring paths 16b and 20a of the valve body 11 are used as cooling gas supply paths capable of supplying cooling gas to the hollow portion 17. In this case, it is necessary to provide exhaust paths 16c and 20b so that the cooling gas supplied to the hollow portion 17 can be exhausted from the hollow portion 17. This causes a flow of cooling gas as shown by the arrows in FIG. 6. The other configurations are the same as those of the pressure control valve 1 according to the first embodiment. Note that a cooling gas supply path communicating with the hollow portion 17 may be provided in addition to the wiring paths 16b and 20a.

[0059] As described above, according to the pressure control valve 1 according to the second embodiment, (4) The pressure control valve 1 according to any one of (1) to (3) is characterized in that the hollow portion 17 is connected to a cooling gas supply path (wiring paths 16b and 20a) capable of supplying a cooling gas.

[0060] The temperature conditions for the surface treatment of the wafer vary depending on the type of process gas, and there are cases where it is necessary to lower the temperature of the valve body 11 of the pressure control valve 1. Conventionally, it was necessary to wait for the temperature of the valve body to drop naturally, which raised concerns about a decrease in the efficiency of the wafer surface treatment process. According to the pressure control valve 1 described in (4), since the hollow portion 17 is connected to a cooling gas supply path (wiring paths 16b / 20a) capable of supplying a cooling gas, it is possible to quickly lower the temperature of the valve body by supplying a cooling gas to the hollow portion 17.

[0061] The above embodiment is merely an example and does not limit the present invention in any way. Therefore, the present invention can be improved and modified in various ways without departing from the scope of the present invention. For example, the planar heater may be a rubber heater or another type of planar heater. [Explanation of symbols]

[0062] 1 Pressure Control Valve 2. Vacuum chamber 3. Exhaust pump 11 Valve body 11a Top surface 11b Bottom side 12 Valve seat 15 Exhaust vent (an example of an opening) 17 Hollow part 18a 1st back side 19a 2nd back 23 First rubber heater (an example of the first planar heater) 24 Second rubber heater (an example of a second planar heater)

Claims

1. A pressure control valve for opening and closing a circular opening that connects a vacuum chamber used in a semiconductor manufacturing device to an exhaust pump that exhausts the vacuum chamber, a valve body that abuts against and separates from a valve seat provided radially outward of the opening; The valve body is a hollow portion located between an upper surface of the valve body on the side of the vacuum chamber and a lower surface of the valve body on the side of the exhaust pump; a first planar heater covering a first back surface of the upper surface in the hollow portion; a second planar heater covering a second back surface of the lower surface in the hollow portion; and heating the entire upper surface and the entire lower surface evenly when the vacuum chamber is evacuated. A pressure control valve comprising:

2. 2. The pressure control valve according to claim 1, a thickness from the upper surface to the first back surface and a thickness from the lower surface to the second back surface are 4 mm or more and 8 mm or less; A pressure control valve comprising:

3. 3. The pressure control valve according to claim 1, the valve body includes an annular seal portion that is in contact with and spaced from the valve seat; the hollow portion is located on a radially inner circumferential side of the annular seal portion; A pressure control valve comprising:

4. 4. The pressure control valve according to claim 1, a cooling gas supply passage capable of supplying a cooling gas is connected to the hollow portion; A pressure control valve comprising:

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