JP2010112391A - Pressure reducing exhaust valve, and pressure reducing device using pressure reducing exhaust mechanism including the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure reducing exhaust valve which is applicable to a pressure reducing device having only one exhaust passage (a main exhaust passage), fast in exhaust velocity and capable of suppressing the soaring of particles, and also to provide a pressure reducing device using a pressure reducing exhaust mechanism including the same. <P>SOLUTION: The pressure reducing exhaust valve 10 is attached in a portion of the exhaust passage 5 with one end communicated with a vacuum chamber 2, and the other end with a vacuum pump 4. The exhaust valve 10 also includes: a pipe part 11 connected to an exhaust passage 5; an on-off valve 12 accommodated in the pipe part to open and close the exhaust passage 5; a porous body 13 with vent pores provided in the on-off valve 12; and a screening amount regulation part 10B, which is provided in the exhaust passage at the upstream or downstream side of the on-off valve 12 to make the screening area of the exhaust passage 5 variable. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a decompression exhaust valve and a decompression device using a decompression exhaust mechanism including the decompression exhaust valve, and in particular, a decompression exhaust valve provided with an opening / closing valve having a porous body, and a decompression exhaust mechanism incorporating the decompression exhaust valve. It is related with a decompression device provided with.

  Conventionally, in a manufacturing process of a semiconductor wafer or a liquid crystal material, for example, a decompression device such as a dry etching device, a sputtering device, or a CVD device is used. The exhaust mechanisms in these apparatuses are provided with a slow exhaust passage in parallel with the main exhaust passage for the purpose of buffering the pressure when the vacuum chamber is decompressed.

A conventional decompression device will be described with reference to FIG. As shown in FIG. 9, the conventional decompression device 41 is provided with an exhaust mechanism 43 that decompresses the inside of the vacuum chamber 42.
The exhaust mechanism 43 has one end communicating with the exhaust port 45 provided in the vacuum chamber 42 and the other end communicating with the vacuum pump 46, and one end communicating with the vacuum chamber 42 via the main exhaust path 47. A slow exhaust passage 49 that communicates with the other end and communicates with the vacuum pump 46 via the main exhaust passage 47 is provided.

The exhaust mechanism 43 includes a first on-off valve (main valve) 48 provided in the main exhaust passage 47, and a second on-off valve (slow exhaust) in parallel with the first on-off valve in the slow exhaust passage 49. Valve) 50.
Further, the exhaust mechanism 43 includes a filter 44 provided at the exhaust port 45 for buffering pressure during exhaust.

In such a conventional pressure reducing device 41, the exhaust is gradually exhausted through the slow exhaust passage 49 at the initial stage of exhaust, and then exhausted at once through the main exhaust passage 47.
However, since the filter 44 is installed at the exhaust port 45, there is a problem that the filter 44 becomes a resistance when exhausting at a time through the main exhaust passage 47, and the exhaust speed is significantly reduced.

As a decompression device for solving this, there is a decompression device 51 shown in FIG. The decompression device 51 includes a slow exhaust passage 52 having one end directly communicating with the vacuum chamber 42 and the other end communicating with the vacuum pump 46 via the main exhaust passage 47. A filter 44 is attached to the slow exhaust port 53.
In the pressure reducing device 51 configured as described above, the exhaust is gently exhausted through the filter 44, the slow exhaust port 53, and the slow exhaust passage 52, and then the second on-off valve 50 and the first on-off valve 48 are opened. It switches and exhausts from the main exhaust path 47 at a stretch.
For this reason, in the decompression device 51, the exhaust speed in the main exhaust passage 47 can be increased, but it is necessary to provide the slow exhaust port 53 separately from the exhaust port 45, which requires a large amount of equipment modification costs. was there.

A main exhaust passage communicating the vacuum chamber and the vacuum pump, a wafer handling system provided with a slow exhaust passage in parallel with the main exhaust passage (see, for example, Patent Document 1), and a variable conductance valve in the slow exhaust passage. A provided horizontal processing furnace has been proposed (see, for example, Patent Document 2).
Japanese Patent Laid-Open No. 61-228648 JP 7-235497 A

By the way, in order to solve the above-described problem, the applicant of the present application has proposed a pressure reducing device 61 including a filter 62 made of a cylindrical porous silica material in a slow exhaust passage 49 as shown in FIG. Japanese Patent Application No. 2007-190462).
However, the conventional pressure reducing device and the pressure reducing device proposed by the applicant of the present application are based on the main exhaust passage and the slow exhaust passage.
For this reason, when switching from the slow exhaust path to the main exhaust path, pressure fluctuations may occur and particles may rise.

In addition, when applied to a pressure reducing device having only one exhaust passage (main exhaust passage), a filter must be provided at the exhaust port of one exhaust passage (main exhaust passage), and the exhaust speed is greatly reduced. There is a problem that it takes a long time to reach the vacuum degree. In addition, since there is always a filter at the exhaust port, there is a problem that the filter becomes a resistance and it is difficult to reach a predetermined degree of vacuum.
Thus, it has been difficult to apply the above-described filter to a decompression device having only one exhaust passage (main exhaust passage).

  The present invention has been made in consideration of the above-described circumstances, and can be applied to a decompression device having only one exhaust passage (main exhaust passage), and a decompression exhaust valve capable of suppressing the rising of particles with a high exhaust speed and the decompression exhaust. An object of the present invention is to provide a decompression device using a decompression exhaust mechanism including a valve.

The decompression exhaust valve according to the present invention made to achieve the above object is a decompression exhaust valve attached to an exhaust passage having one end communicating with a vacuum chamber and the other end communicating with a vacuum pump. A pipe part connected to the exhaust path, an open / close valve accommodated in the pipe part for opening and closing the exhaust path, a porous body part having a vent provided in the open / close valve, and And a shielding amount adjusting unit provided in an exhaust path on the upstream side or downstream side of the on-off valve and having a variable shielding area of the exhaust path.
Here, it is desirable that the shielding amount adjusting unit makes the shielding area of the exhaust passage variable by a combination of a plurality of shielding members.
Moreover, it is desirable that the porous body portion of the vacuum exhaust valve is a ceramic porous sintered body formed by stirring foaming.

  By configuring the pressure reducing exhaust valve in this way, when the vacuum chamber starts to be depressurized, the gas in the chamber flows through the porous body portion of the on-off valve, and further, a stepwise flow rate increase adjustment (shielding area) in the shielding amount adjusting portion. The pressure reduction speed is adjusted gently and finely. Further, after the gradual decompression step, exhaust at an increased exhaust speed can be performed by opening the on-off valve. Therefore, in the decompression process of the vacuum chamber, a sudden decompression in the chamber can be surely avoided, and the rise of particles can be suppressed.

Further, a decompression device according to the present invention made to achieve the above object is a decompression device comprising a vacuum chamber and an exhaust mechanism for decompressing the inside of the vacuum chamber, wherein the exhaust mechanism has one end at the vacuum chamber. An exhaust passage that communicates with the vacuum pump, and a decompression exhaust valve attached to the exhaust passage, wherein the decompression exhaust valve includes a pipe portion connected to the exhaust passage, An open / close valve housed in a pipe portion for opening and closing the exhaust passage, a porous body portion having a vent provided in the open / close valve, and an exhaust passage upstream or downstream of the open / close valve And a shielding amount adjusting unit in which the shielding area of the exhaust passage is variable.
Here, it is desirable that the shielding amount adjusting unit makes the shielding area of the exhaust passage variable by a combination of a plurality of shielding members.
Moreover, it is desirable that the porous body portion of the vacuum exhaust valve is a ceramic porous sintered body formed by stirring foaming.

  By configuring the decompression device in this way, when the vacuum chamber starts to be decompressed, the gas in the chamber flows through the porous body portion of the on-off valve and further adjusts the flow rate in a stepwise manner (the shielding area By adjusting), the pressure reduction speed is adjusted gently and finely. Further, after the gradual decompression step, exhaust at an increased exhaust speed can be performed by opening the on-off valve. Therefore, in the decompression process of the vacuum chamber, a sudden decompression in the chamber can be surely avoided, and the rise of particles can be suppressed.

  According to the present invention, a decompression device that can be applied to a decompression device having only one exhaust passage (main exhaust passage), has a fast exhaust speed and can suppress the rise of particles, and a decompression exhaust mechanism including the decompression exhaust valve are used. A decompression device can be obtained.

A pressure reducing exhaust valve according to an embodiment of the present invention and a pressure reducing device using a pressure reducing exhaust mechanism including the pressure reducing exhaust valve will be described with reference to the drawings.
1 is a schematic configuration diagram of a pressure reducing device according to the present invention, and FIG. 2 is a side sectional view showing a pressure reducing exhaust valve according to the present invention. 3 is a front view of the filter valve provided in the pressure reducing exhaust valve of FIG. 2, showing a state in which the opening / closing body is closed, and FIG. 4 is a view showing a state in which the opening / closing valve is opened. Further, FIG. 5 is a plan view of the shielding adjusting portion provided in the pressure reducing exhaust valve of FIG. 2, showing a state where the shutter plate is closed, and FIG. 6 is a diagram showing a state where the shutter plate is opened. .

As shown in FIG. 1, a decompression device 1 according to the present invention includes a vacuum chamber 2 that is decompressed to a vacuum and serves as a processing chamber, and further includes an exhaust mechanism 3 that decompresses the vacuum chamber 2 to a vacuum.
The exhaust mechanism 3 has one end communicating with the vacuum chamber 2 through an exhaust port 2 a provided at the bottom of the vacuum chamber 2 and the other end communicating with the vacuum pump 4. And a pressure reducing exhaust valve 10 attached thereto.
The decompression exhaust valve 10 includes a filter valve 10A, and a shielding amount adjusting unit 10B provided either in front of or behind the filter valve 10A along the exhaust direction of the exhaust passage 5 (rear in this embodiment). Is provided.

  As shown in FIGS. 3 and 4, the filter valve 10 </ b> A includes a pipe part 11 connected to the exhaust path 5, and a circle that is rotatably accommodated in the pipe part 11 and opens and closes the exhaust path 5. A plate-like on-off valve 12 and a porous body portion 13 provided on the on-off valve 12 and having a disc-like vent hole are provided. That is, the opening / closing valve 12 is configured by the outer peripheral portion of the porous body portion 13 being held by the inner peripheral portion of the ring-shaped ring portion 12a.

A rotating shaft 14 is attached to the back surface of the ring portion 12a. The rotation shaft 14 is attached so as to be perpendicular to the axis of the exhaust passage 5 (pipe portion 11) and to be rotatable with respect to the tube portion 11.
A gear portion 14 a is formed at the end of the rotating shaft 14, and meshes with a gear portion 15 a formed at the end of the drive shaft 15 outside the tube portion 11. That is, by rotating the drive shaft 15 by a drive means (not shown) such as a motor, the rotation shaft 24 is rotated, the on-off valve 12 is rotated, and the exhaust passage 5 (pipe portion 11). Are configured to open and close.
The gear portion 14 a of the rotating shaft 14 and the gear portion 15 a of the drive shaft 15 are accommodated in the casing 16.

Furthermore, the porous body portion 13 will be described.
The porous body portion 13 includes a metal porous body, a glass porous body, a quartz porous body, a porous sintered body obtained by ordinary powder sintering, a porous sintered body obtained by sintering ceramic fibers, A porous sintered body formed by foaming and sintered can be used.
In particular, a ceramic porous sintered body formed by stirring foaming is desirable. Such a porous ceramic body can be manufactured by the method described in Japanese Patent Application Laid-Open Nos. 2000-264753 and 2003-238267 filed earlier by the present applicant.
Here, as a raw material for producing the porous body portion, various materials such as a metal porous body as well as alumina, zirconia, silicon nitride, silicon carbide, mullite, cordierite, silica, hydroxide apatite, and the like are used. Among these, silicon carbide, which is particularly excellent in corrosion resistance and mechanical properties, is preferable.

The average pore diameter is preferably 5 to 90 μm, and the porosity is preferably 30 to 65%.
In particular, in the case of silicon carbide, an average pore diameter of 30 to 90 μm and a porosity of 55 to 65% are preferable. Specifically, the pores measured using a mercury porosimeter (based on JIS R1634 1998) have an average pore diameter of 30 μm or more and 90 μm or less, and the pores are communication holes of 10 μm or more and 20 μm or less (based on SEM observation). It preferably has a three-dimensional network skeletal structure in communication.

In addition, this porosity (machined to a specific volume and measuring this weight, the volume, weight and SiC density: calculated from 3.21 g / cm ³ ) is 55% or more and less than 65%. It is preferable.
The average pore diameter and porosity can be varied by adjusting raw material powder and stirring foaming conditions in the production process, and a ceramic porous sintered body having desired average pore diameter and porosity is obtained. be able to.

Further, the shielding amount adjusting unit 10B is configured so that the shielding area of the exhaust passage 5 is variable, and as shown in FIG. 5, the pipe portion 17 connected to the exhaust passage 5 and the inside of the pipe portion 17 respectively. A plurality of (six in the figure) shutter plates 18 (shield members) accommodated so as to be rotatable. The shutter plates 18 are each formed in a long plate shape as shown in the drawing, and are arranged so that the side portions in the longitudinal direction overlap the adjacent shutter plates 18. Further, in a state in which all the shutter plates 18 are closed (side portions are overlapped), a shielding plate having a cross-sectional shape of the exhaust passage 5 is formed by all the shutter plates 18.
In the shutter plate 18, a synthetic resin member (not shown) is provided in a portion overlapping the adjacent shutter plate 18 so as to improve the sealing performance when the shutter plate 18 is closed.

Each shutter plate 18 is provided with a rotation shaft 19 along the longitudinal direction thereof, and the rotation shaft 19 is rotatably supported by the tube portion 17 so that the shutter plate 18 rotates in the tube portion 17. It is pivotally supported. That is, the exhaust passage 5 is brought into a closed state (state shown in FIG. 5) or an open state (state shown in FIG. 6) by the rotation of each shutter plate 18.
One end of the rotating shaft 19 protrudes outward. A driving shaft 20 provided at the end of the rotating shaft 19 is rotated by driving means (not shown) such as a motor to rotate the rotating shaft 19, and the shutter plate 18 is moved. It is designed to rotate.

The drive shafts 20 corresponding to the shutter plates 18 are independently driven and controlled. As a result, only the predetermined shutter plate 18 is opened, the shielding area of the exhaust passage 5 is set to a desired state by the combination of the shutter plates 18, and the gas flow rate passing through the pressure reducing exhaust valve 10 can be finely adjusted. It becomes.
Each shutter plate 18 is preferably driven so that the rotation angle thereof can be finely adjusted. With such a configuration, the gas flow rate can be adjusted more finely.
Further, since the shielding area of the exhaust passage 5 is variable in the shielding amount adjusting unit 10B as described above, it is possible to adjust the optimum exhaust amount (exhaust speed) according to the capacity of the vacuum chamber 2. .

Next, the operation of the decompression device will be described. When depressurizing the vacuum chamber 2 serving as a processing chamber, at the start of depressurization, first, in the depressurization exhaust valve 10 provided in the exhaust passage 5, as shown in FIG. From the closed state, as shown in FIG. 7B, for example, only the central shutter plate 18 is rotated and opened.
Further, as shown in FIG. 7B, the open / close valve 12 of the pressure reducing exhaust valve 10A is closed, and the vacuum pump 4 is operated. The gas in the vacuum chamber 2 flows to the vacuum pump 4 via the exhaust port 2a, the exhaust path 5, the porous body portion 13 of the pressure reducing exhaust valve 10A, and the shutter plate 18 opened by the flow rate adjusting mechanism 10B. The inside begins to be gradually decompressed.

After a predetermined time has elapsed or when the inside of the vacuum chamber 2 reaches a predetermined atmospheric pressure, the other shutter plates 18 are opened sequentially (see FIG. 7C), the gas flow rate is gradually increased, and finally FIG. ) All the shutter plates 18 are opened as shown in FIG.
At this time, the outer diameter of the porous body portion 13 of the filter valve 10A is set to 25 mm, the average pore diameter is 5 to 90 μm, and the porosity is 30 to 65%. Thus, the sudden pressure reduction is avoided, the rise of particles is suppressed, and the pressure can be reduced gradually. Further, by sequentially opening the plurality of shutter plates 18, the gas flow rate can be gradually increased, and the decompression speed can be adjusted more finely.

Then, after this gradual decompression step, the drive shaft 15 is rotated and the rotary shaft 14 is rotated, thereby rotating the on-off valve 12 and opening the on-off valve 12.
By opening the on-off valve 12, the buffering action of the porous body portion 13 of the decompression exhaust valve 10 is weakened, and the exhaust is performed at a high exhaust speed.

As described above, according to the embodiment of the present invention, when the vacuum chamber 2 starts to be depressurized, the gas in the vacuum chamber 2 flows through the porous body portion 13 of the filter valve 10A (open / close valve 12) and is further shielded. The pressure reduction speed is adjusted gently and finely by the stepwise flow rate increase adjustment (adjustment of the shielding area) in the amount adjustment unit 10B. Further, after the gradual decompression step, exhaust at an increased exhaust speed can be performed by opening the on-off valve 12.
Therefore, in the decompression process of the vacuum chamber 2, sudden decompression in the chamber can be reliably avoided, and the rise of particles can be suppressed.

  In the embodiment described above, the shielding amount of the exhaust passage 5 is adjusted by combining the open / close state of the shutter plate 18 that can be opened and closed as the shielding member used in the shielding amount adjusting unit 10B. However, it is not limited to that.

For example, instead of the shielding amount adjusting unit 10B, a shielding amount adjusting unit 10C having a structure close to the diaphragm structure of the camera as schematically shown in FIGS. 8A to 8C is provided in the exhaust passage 5, You may use as a shielding amount adjustment part in the pressure reduction exhaust valve 10.
8A is a plan view of the shielding amount adjusting unit 10C, showing a closed state, FIG. 8B is a diagram showing a slightly opened state, and FIG. 8C is completely opened. It is a figure which shows a state.

  As shown in the figure, the shielding amount adjusting unit 10C includes a plurality of (six in the figure) blade members 21 (shielding members) and a plurality of pins that engage with elongated cam holes 21a formed in each blade member 21, respectively. 23. Each blade member 21 is provided so as to be rotatable about a rotation shaft 22, and the pin 23 is movable along a track indicated by a one-dot chain line in FIG.

With this configuration, for example, when the pin 23 is moved along the track by the driving means (not shown) from the closed state shown in FIG. 8A, the blade member 21 is rotated along the cam hole 21a. As shown in FIG. 8B, the opening 25 is generated. The opening 25 gradually increases with the movement of the pin 23 and finally becomes a complete open state as shown in FIG.
That is, by controlling the movement amount of the pin 23, the combination state of the blade member 21 is changed, and the size of the opening 25 is determined. Therefore, the shielding amount of the open exhaust path 5 can be adjusted. Become.

  In the above embodiment, the case where the pressure reducing exhaust valve is mounted on a pressure reducing device having only one exhaust passage has been described as an example, but a pressure reducing device having two exhaust passages as in the prior art is also described. Of course, it can be installed.

FIG. 1 is a schematic configuration diagram of a decompression device according to the present invention. FIG. 2 is a side sectional view showing a pressure reducing exhaust valve according to the present invention. FIG. 3 is a front view of the filter valve provided in the pressure reducing exhaust valve of FIG. 2 and shows a state in which the opening / closing body is closed. 4 is a view showing a state in which the on-off valve is opened in the filter valve of FIG. FIG. 5 is a plan view of the shielding adjusting portion provided in the pressure reducing exhaust valve of FIG. 2 and shows a state in which the shutter plate is closed. FIG. 6 is a diagram illustrating a state in which the shutter plate included in the shielding amount adjusting unit in FIG. 5 is opened. FIG. 7 is a diagram showing an operation example of the pressure reducing exhaust valve according to the present invention. FIG. 8 is a diagram schematically illustrating another form of the shielding adjustment unit. FIG. 9 is a schematic configuration diagram showing a conventional decompression device. FIG. 10 is a schematic configuration diagram showing another conventional decompression device. FIG. 11 is a schematic configuration diagram showing the decompression device previously proposed by the applicant of the present application.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pressure reducing device 2 Vacuum chamber 2a Exhaust port 3 Exhaust mechanism 4 Vacuum pump 5 Exhaust passage 10 Pressure reducing exhaust valve 10A Filter valve 10B Shielding amount adjusting part 11 Pipe part 12 On-off valve 12a Ring part 13 Porous body part 14 Rotating shaft 14a Gear Part 15 Drive shaft 15a Gear part 16 Casing 17 Pipe part 18 Shutter plate (shielding member)
19 Rotating shaft 20 Drive shaft 21 Blade member (shielding member)
21a Cam hole 22 Rotating shaft 23 Pin

Claims (6)

In a pressure reducing exhaust valve attached to an exhaust path having one end communicating with a vacuum chamber and the other end communicating with a vacuum pump,
The pressure reducing exhaust valve is a porous body having a pipe part connected to the exhaust path, an open / close valve that opens and closes the exhaust path, and a vent hole provided in the open / close valve. And a shielding amount adjusting unit provided in an exhaust path upstream or downstream of the on-off valve and having a variable shielding area of the exhaust path.   The pressure reducing exhaust valve according to claim 1, wherein the shielding amount adjusting unit makes the shielding area of the exhaust passage variable by a combination of a plurality of shielding members.   The reduced pressure exhaust valve according to claim 1 or 2, wherein the porous body portion of the reduced pressure exhaust valve is a ceramic porous sintered body formed by stirring foaming. In a decompression device including a vacuum chamber and an exhaust mechanism for decompressing the inside of the vacuum chamber,
The exhaust mechanism has an exhaust passage having one end communicating with the vacuum chamber and the other end communicating with a vacuum pump, and a pressure reducing exhaust valve attached in the exhaust passage,
The decompression exhaust valve includes a pipe portion connected to the exhaust passage, an on-off valve that opens and closes the exhaust passage, and a porous body that is provided in the on-off valve and has a vent hole. And a shielding amount adjusting unit provided in an exhaust passage upstream or downstream of the on-off valve and having a variable shielding area of the exhaust passage.   The decompression device according to claim 4, wherein the shielding amount adjusting unit makes the shielding area of the exhaust passage variable by a combination of a plurality of shielding members.   6. The decompression apparatus according to claim 4, wherein the porous body portion of the decompression exhaust valve is a ceramic porous sintered body formed by stirring foaming.

Images