JPH0599348A - Gate valve - Google Patents

Abstract

PURPOSE:To improve seal performance of a gate valve by arranging a movable unit, gate plates, etc., in a single chamber and also providing the gate plates or links in both sides of the movable unit to close opening parts, formed so as to be mutually opposed to the chamber, by each gate plate. CONSTITUTION:A chamber 23, in which opening parts 22a, 22b are respectively formed in mutually opposed side walls 21a, 21b, is provided in a gate valve 20 to provide a movable unit 24 arranged in the center between side walls in the chamber 23 and movable in a direction along side walls 21a, 21d A pair of links 25a, 25b are swivelably mounted to the movable unit 24 to arrange gate plates 26a, 26b in a condition rotatably supported respectively to a point end side of each link 25a, 25b, on both sides of the movable unit 24. The movable unit 24 is driven by an actuator. Stoppers 27a, 27b provided on the side walls 21a, 21b are brought into contact with end faces of the gate plates 26a, 26b moved to positions opposed to the openings 22a, 22b according to moving the movable unit 24, to impede only movement in a vertical direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gate valve used for opening and closing a substrate loading / unloading port in a processing chamber of a semiconductor substrate processing apparatus, and in particular, maintains high sealing performance even when the loading / unloading port has a large diameter. Gate valve.

[0002]

2. Description of the Related Art In the production of semiconductors, the demand of which is increasing more and more in recent years, a substrate processing step in a special atmosphere is indispensable. That is, most of the steps such as forming a thin film on the surface of the substrate or processing the same are performed in a special gas atmosphere under low pressure. Specifically, the substrate is placed in a vacuum chamber called a processing chamber. Done.

Therefore, the hermeticity of the processing chamber is important for setting the pressure condition that affects the yield and quality of the product to a desired value, and also introduces a toxic and highly corrosive gas into the processing chamber. It is also important in terms of safety in the process. For example, when a corrosive gas leaks in a thin film forming process such as CVD, it is dangerous and may damage parts other than the vacuum chamber of the processing apparatus.

In order to secure the sealing property of the processing chamber, leakage of the substrate loading / unloading port in the processing chamber becomes a problem, and the performance of a device called a gate valve for opening / closing the loading / unloading port is important. As the gate valve, the one having the structure shown in FIG. 4 was used.

This is a movable body 4 which moves up and down along a side wall 3 in which a carry-in / out port 2 of the processing chamber 1 is formed, and the movable body 4.
Link 5 that is swingably attached to the
Of the gate plate 6 disposed on the side wall 3 side of the movable body 4 while being pivotally supported on one end side of the movable body 4, a stopper 7 formed above the carry-in / out port 2 on the side wall 3, and the other end side of the link 5. A tension spring 8 provided between the movable body 4 and the body 4 to urge the link 5 clockwise in FIG. 4 and an actuator (not shown) for driving the movable body 4 are provided.

Then, when the movable plate 4 is further raised from the state in which the gate plate 6 that has risen as the movable body 4 rises contacts the stopper 7, the link 5 swings counterclockwise in FIG. As a result of the leftward movement of the gate plate 6, the gate plate 6 is pressed against the peripheral edge portion (hereinafter referred to as a sheet portion) of the carry-in / out port 2 to which the sealing material 9 is attached on the side wall 3 to close the carry-in / out port 2. On the contrary, by lowering the movable body 4, the gate plate 6 is lowered while being separated from the side wall 3 by the restoring force of the tension spring 8 to open the carry-in / out port 2.

In this case, the movable body 4 of the gate valve
Alternatively, the gate plate 6 and the like are arranged in a carry-in / carry-out vacuum chamber 10 connected to the carry-in / carry-out port 2 of the process chamber 1 in order to always maintain the pressure in the process chamber 1 at a predetermined pressure or less,
The side wall 3 is a wall of a chamber forming the loading / unloading vacuum chamber 10. (Usually, the substrate is carried in and out of the apparatus through such a carrying-in / carrying-out vacuum chamber. For example, at the time of carrying-in, the carrying-in / carrying-out vacuum chamber 10 that has been brought to the atmospheric pressure is carried in once. After the loading / unloading vacuum chamber 10 has the same pressure as the processing chamber, the loading / unloading port 2 is opened by the operation of the gate valve, and the substrate in the loading / unloading vacuum chamber 10 is further loaded into the processing chamber. )

The actuator for driving the movable body 4 is composed of an air cylinder or the like arranged outside the preliminary vacuum chamber 10. The movable body 4 penetrates the lower wall of the chamber forming the preliminary vacuum chamber 10. The rod 11 which supports 4 is moved up and down.

[0009]

The above-mentioned conventional gate valve is an actuator such as a cylinder that can move only linearly and realizes movement of the gate plate in two directions (vertical direction and horizontal direction). Although it has an excellent feature that the loading / unloading port can be easily opened / closed by switching the operation of the actuator, there is a problem that the sealing performance deteriorates as the loading / unloading port has a larger diameter.

That is, in order to press the gate plate 6 with a sufficient force so that the sealing material 9 is sufficiently crushed and maintain a high sealing performance, the reaction force of this force and the pressure difference between both sides of the gate plate 6 are strengthened. However, in the case of the above-described conventional structure, the rod 6 is bent and deformed, so that the lever 5 does not work effectively, and the force for pressing the gate plate 6 cannot be obtained sufficiently, resulting in leakage. I was afraid to do it. The larger the loading / unloading port, the greater the pressing force required to crush the sealing material 9, and the greater the force applied to the gate plate due to the pressure difference between the two sides of the gate plate. Was getting bigger.

[0011] The limitation of the sealing performance is not desirable and dangerous for realizing high quality of the product as described above, and the loading / unloading port cannot be made large. This has been a problem because it hinders an increase in the diameter of a liquid crystal substrate that accompanies an increase in the diameter of a rare semiconductor substrate (wafer) and an increase in the size of a display or the like.

The present invention has been made in view of the above conventional problems, and is a gate valve used for opening and closing a substrate loading / unloading port in a processing chamber of a semiconductor substrate processing apparatus.
In particular, it is an object of the present invention to provide a gate valve that maintains high sealing performance even when the loading / unloading port has a large diameter.

[0013]

SUMMARY OF THE INVENTION A gate valve according to the present invention is a chamber having openings formed in opposite side walls, and is disposed between the side walls in the chamber and movable in a direction along the side walls. A movable body, a pair of links swingably attached to the movable body, and a gate plate capable of closing the opening by being pressed against the opening, A pair of gate plates arranged on both sides of the movable body so as to face each side wall in a state of being axially supported, an actuator for driving the movable body, and the movable body provided on the side wall as the movable body moves. It is characterized in that it comprises a stopper that comes into contact with the end face of the gate plate that has moved to a position facing the opening and blocks only the movement of the gate plate in the direction along the side wall.

[0014]

The gate valve of the present invention is installed in a state where one opening of the chamber is connected to a loading / unloading port for opening and closing, and when the movable body is moved by operating an actuator, the chamber is moved by each gate plate. It is possible to switch between the state in which each opening of the chamber is closed from the inside and the state in which each gate plate is separated from each opening, so that the carry-in / out port can be sealed with good sealability through the opposite opening of this chamber. It can be opened and closed.

That is, each gate plate can move so as to move toward and away from each side wall by swinging of each link, and when the movable body is moved to the side facing the stopper, each gate plate moves to the stopper. Until it abuts, it is forced to move along each side wall, but after abutting against the stopper (each gate plate has moved to the position facing the opening), movement along the side wall is blocked, and the link It is forced to move in the direction toward each side wall with rocking.

Therefore, when the movable body is moved toward the stopper, the gate plate is automatically pressed against each opening to close each opening, and conversely, the movable body is provided on the side opposite to the stopper. If the gate plate is moved to, the gate plates can be separated from the openings to open the openings. And
The force with which the gate plate is pressed against the opening when the movable body is moved toward the stopper is sufficiently large because the output of the actuator that drives the movable body is amplified by the lever action of the link. In addition, the carry-in / out port connected to this opening is closed with a high hermeticity.

This is because the gate plates are provided on both sides of the movable body and the pair of gate plates are pressed against the respective openings so as to move to both sides of the movable body. The reaction force is applied to the movable body from both sides to cancel each other out, and bending deformation of the rod supporting the movable body (that is, movement in the direction orthogonal to the side wall of the movable body) hardly occurs, and the movable body is linked. This is because the lever action ensures that the lever is pressed against the opening with a large force.

Further, even if there is a difference between the pressure applied to the one surface side of the gate plate and the pressure applied to the other surface side in the state where the opening is thus closed, there is an action of canceling the reaction forces. However, the force due to this pressure difference still acts on the movable body, and even if a small leak occurs here due to the deterioration of the sealing performance of one of the gate plates, the pressing force of the other gate plate will rather increase. Therefore, the closed state of the carry-in / out port is sufficiently maintained in the entire chamber by at least the sealing by the other gate plate.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. Reference numeral 20 in FIG. 1 is a gate valve. FIG. 1 shows a case where the gate valve 20 is arranged between the loading / unloading port 16 of the processing chamber 15 and the connection port 18 of the loading / unloading vacuum chamber 17.

The gate valve 20 is provided with a chamber 23 in which openings 22a and 22b are formed in opposite side walls 21a and 21b, respectively, and the side walls 21a and 21b are arranged in the center between the side walls in the chamber 23. A movable body 24 that is movable in a direction along the direction (in this case, the vertical direction)
A pair of links 25a and 25b swingably attached to the movable body 24, and a pair of gate plates 26a arranged on both sides of the movable body 24 in a state of being axially supported by the tip ends of the links. 26b, an actuator (not shown) for driving the movable body 24, and the gate plates 26a, 26b provided on the side walls 21a, 21b and moved to positions facing the openings 22a, 22b as the movable body 24 moves. Of the stoppers 27a and 27b that come into contact with the end face of the stopper and block only the movement in the vertical direction.

The chamber 23 is a main body 2 having an open top.
3a and an upper lid 23b that seals and closes the upper opening of the body portion 23a, and has a rectangular parallelepiped shape as a whole, and the side wall of the body portion 23a is the side walls 21a, 2
It is 1b. The inner surfaces of the side walls 21a and 21b of the chamber 23 and the openings 22a and 22b
Sealing members 28a and 28b are attached to the peripheral edge of the sheet, and seat portions are formed so that the openings 25a and 22b are closed by pressing the gate plates 26a and 26b.

The movable body 24 is supported by a rod 29 which is vertically slidable while penetrating the upper lid 23b, and as shown in FIGS. 2 and 3, has a strip-like shape as a whole. It is said that. Both ends of the movable body 24 are
A linear guide 30 attached to the inner side surface of the chamber 23 (the inner side surface on the opposite side and the front side in FIG. 1) is guided so as to be vertically movable. The rod 29 that supports the movable body 24 is driven by an actuator such as an air cylinder arranged above the outside of the chamber 23.

The swing directions of the links 25a and 25b are along a plane which is substantially orthogonal to the side walls 21a and 21b and is substantially parallel to the moving direction of the movable body 24 (in this case, a plane parallel to the paper surface in FIG. 1). In total, eight pieces are provided at four positions in the longitudinal direction of the movable body 24 so as to form a pair, and the upper and lower combinations form a parallel link. Therefore, each gate plate 26a, 26b
Is always facing the side walls 21a, 21b, and the side walls 21a, 21b
It is configured to move so as to move closer to and away from b.

Each gate plate 26a, 26b is separated from the movable body 24 by the swing of each link 25a, 25b (in this case, each link 25a, 25b is oriented in the horizontal direction). The lengths and the like of the links 25a and 25b are set so that the distance between the outer surfaces of 26a and 26b is larger than the distance between the inner surfaces of the side walls 21a and 21b. In addition, each link 25a, 25b
Connects the gate plates 26a and 26b to the side walls 21a and 21b.
Each gate plate 26a, 26b for placement inside the
Is more than the angle at which the stopper 2 is farthest from the movable body 24.
It is in a state of swinging toward the 7a, 27b side (in this case, the tip side of each link is inclined downward as shown in FIG. 1).

That is, in this case, the movable body 24 and each of the gate plates 26a and 26b are inserted and assembled in the chamber 23 with the upper lid 23b removed. Since each link 25a, 25b is set in the horizontal direction because it is set,
The distance between the outer surfaces of the gate plates 26a and 26b is the chamber 2
It is larger than the distance between the inner surfaces of 3 and cannot be inserted. Therefore, each link 25a, 25
It is necessary to oscillate b upward or downward. In this case, insert each link 25a, 25b with the links oscillated downward (on the side where the stoppers 27a, 27b are). Must. However, in the case of the present embodiment, since the moving direction of the movable body 24 is the vertical direction and the stoppers 27a and 27b are arranged on the lower side, if the action of gravity is left, the links 25a and 25b will naturally move.
Does not require any particular operation because it is in a state of swinging toward the stoppers 27a and 27b.

Next, the stoppers 27a, 27b are provided below the openings 22a, 22b by a distance in consideration of the dimensions of the gate plates 26a, 26b. The upper surface that abuts against is a horizontal surface, and for example, the upper surface portion is made of a material having a low friction coefficient so that the gate plates 26a and 26b that abut on this surface can easily slide in the horizontal direction. ..

In FIG. 1, reference numeral 31 is a shaft seal for sealing the penetrating portion of the rod 29, and reference numerals 32, 33 and 34 are processing portions with the joint portion of the upper lid 23b and the chamber 23. It is a sealing member that seals the connection between the chamber 15 and the chamber, and the connection between the chamber 23 and the loading / unloading vacuum chamber 17.

With the gate valve constructed as described above, when the actuator is operated to lower the movable body 24, the gate plate 26a, 26b is used to open each opening 2.
2a and 22b are closed from the inner side, and when the movable body 24 is raised, the gate plates 26a and 26b are opened to the openings 22a and 22a.
This chamber 2 is separated from 22b and retracts upward.
Through the openings 22a and 22b facing each other, the loading / unloading port 16 of the processing chamber 15 can be opened / closed with respect to the inside of the loading / unloading preparation chamber 17 with good sealing property to load / unload substrates.

That is, the movable body 24 is attached to the stopper 27.
When moved to the side facing a and 27b, each gate plate 26
The a and 26b are forced to move downward only until they come into contact with the stoppers 27a and 27b, but they come into contact with the stoppers 27a and 27b (the gate plates 26a and 26b).
b has moved to a position facing each opening 22a, 22b), the downward movement is blocked, and each link 25a2 is blocked.
With the swing of 5b, the movement in the horizontal direction is forced.

Moreover, since the links 25a and 25b are in the state of swinging downward as described above, the directions of movement of the gate plates 26a and 26b at this time are the respective openings 22a and 22b. The direction is toward. Then, the links 25a, 25b become horizontal and the gate plates 26a, 26
Each gate plate 26 when b is farthest from the movable body 24
Since the distance between the outer surfaces of the a and 26b is larger than the distance between the inner surfaces of the side walls 21a and 21b, the gate plates 26 facing the openings 22a and 22b are formed.
The movements of a and 26b are performed until the gate plates 26a and 26b are sufficiently pressed against the sheet portions on the peripheral edges of the openings 22a and 22b.

Therefore, if the movable body 24 is lowered,
The gate plates 26a and 26b are automatically pressed to close the openings 22a and 22b. Conversely, if the movable body 24 is raised, the gate plates 26a and 26b are opened to the openings 22a and 22b. The openings 22a and 22b can be opened by separating the openings 22a and 22b and retreating upward. Then, when the movable body 24 is lowered, the gate plates 26a, 2
The force with which 6b is pressed is sufficiently large because the output of the actuator that drives the movable body 24 is amplified by the lever action of each link 25a, 25b, and as a result, the carry-in / out port 16 is brought into the carry-in / out vacuum chamber 17 It will be closed with high sealing property.

Because the gate plates 26a and 26b are provided on both sides of the movable body 24, the pair of gate plates 26a and 26b are provided.
Since the a and 26b are pressed so as to move to both sides of the movable body 24, each gate plate 26
The reaction force of the force pressing a and 26b is
In addition, since the movable body 24 is supported not only by the rod 29 but also by the linear guide 30, the horizontal displacement of the movable body 24 hardly occurs, and each gate plate 26a, 26b is a link 25a,
This is because the lever action of 25b surely presses it with a large force.

Then, for example, even if the pressure in the processing chamber 15 is larger than the pressure in the loading / unloading vacuum chamber 17 and the reaction forces cancel each other, the force for pushing the movable body 24 to the right side in FIG. Even if a slight leak occurs from the seat portion on the side of the opening 22a due to the effect of the action of the gate plate 26a on the left side and the sealing performance by the gate plate 26a on the left side is reduced, the pressing force of the other gate plate 26b is rather increased. This is because the leaked gas stays at least in the chamber 23 and is not mixed in the carry-in / out vacuum chamber 17 due to the sealing by the other gate plate 26b.

Therefore, according to the above gate valve,
By making each opening 22a, 22b (carry-in / out port 16) to have a large diameter, the required pressing force of the gate plates 26a, 26b is increased, and the pressure receiving area is increased so that the pressure difference causes the gate plates 26a, 26b to increase. Even if the force applied to the processing chamber is increased, the high sealing performance is maintained, and the loading / unloading port 16 of the processing chamber 15 can be easily opened and closed as in the conventional case.

The present invention is not limited to the above-mentioned embodiment, but various modifications can be made. For example, the moving direction of the movable body is not limited to the vertical direction and may be the horizontal direction. However, in this case, the gate plates 26a and 26b are connected to the side walls 21a and 21b.
Since gravity does not work in the direction of separating the gate plates from each other, in order to perform smooth opening and closing, the gate plates 26a and 26b are connected to the side walls 21a and
It is preferable to provide a spring or the like for biasing the links 25a and 25b in a direction in which they are separated from 21b.

The chamber 23 is not necessarily the processing chamber 1
It is not necessary to form it separately from the chamber for forming 5 and the like, and for example, it may be formed integrally with the chamber of the processing chamber 15 or as a part of the chamber of the carry-in / out vacuum chamber 17. ..

Further, it goes without saying that the present invention is not limited to the processing apparatus for semiconductors and the like as described above, but can be used to close the opening of any closed chamber and has the same effect.

[0038]

As is apparent from the above description, according to the gate valve of the present invention, even if each opening has a large diameter due to an increase in the size of the loading / unloading port to be opened / closed, a high sealing performance is achieved. This opening and closing can be easily performed as in the conventional case while maintaining the performance. Therefore, in a semiconductor or liquid crystal substrate processing apparatus, by applying the present invention, the problem of leakage from the gate valve of the processing chamber is solved,
There is an effect that it is possible to cope with a large substrate.

[Brief description of drawings]

FIG. 1 is a side sectional view showing a state in which a gate valve of the present invention is installed between a processing chamber and a loading / unloading vacuum chamber.

FIG. 2 is a view on arrow II in FIG.

3 is a view on arrow III in FIG. 2. FIG.

FIG. 4 is a side sectional view for explaining a conventional gate valve.

[Explanation of symbols]

 21a, 21b Side wall 22a, 22b Opening 23 Chamber 24 Movable body 25a, 25b Link 26a, 26b Gate plate 27a, 27b Stopper

Claims (1)

[Claims] 1. A chamber having openings formed in opposite side walls, and a movable body disposed between the side walls in the chamber and movable in a direction along the side walls.
A pair of links swingably attached to the movable body,
A gate plate capable of closing the opening by being pressed against the opening, the pair being arranged on both sides of the movable body so as to face each side wall while being axially supported by the tip side of the link. Of the gate plate, an actuator for driving the movable body, and an end surface of the gate plate which is provided on the side wall and has moved to a position facing the opening along with the movement of the movable body so as to contact the end surface of the gate plate. A gate valve comprising a stopper that blocks only movement in the direction along the side wall.