CN101471241B - Vacuum apparatus, vacuum processing system and pressure control method of vacuum chamber - Google Patents

Abstract

The invention relates to a vacuum device, a vacuum processing system and a pressure control method of a vacuum chamber. Even when the supply of air for the operation of the gate valve in the vacuum chamber is insufficient, the gate valve can be prevented from being suddenly opened. In the pressure control mechanism (201), when the supply of air to the cylinder (123) is stopped, the port of the mechanical valve (121) is switched, the pneumatic valve (113) is opened, and the external air passes through the vacuum leak port (109) and the gas introduction pipe. (111) and the communicating hole (107) gradually flow into the transfer chamber (3) in a vacuum state. The pressure control of the transfer chamber (3) is carried out by using the check valve (103) and the buffer tank (105) while ensuring the operating air of the cylinder (47), so that the sudden opening of the gate valve (7b) can be prevented .

Description

Vacuum device, vacuum processing system and pressure control method for vacuum chamber

technical field

The present invention relates to a vacuum device for performing plasma processing or the like on a target object such as a glass substrate for a flat panel display (FPD) or a semiconductor wafer under vacuum conditions, a vacuum processing system equipped with the vacuum device, and pressure control of a vacuum chamber method.

Background technique

In the manufacturing process of FPDs and semiconductor devices represented by liquid crystal displays (LCDs), various processes such as etching and film formation are performed on objects to be processed under vacuum conditions. In order to perform the above-mentioned processing using plasma, a vacuum processing system having an evacuable vacuum processing chamber is used.

In the vacuum processing system, a transfer chamber is provided adjacent to a vacuum processing chamber as a processing container for processing an object to be processed, and includes a transfer device for transferring the object to be processed to the vacuum processing chamber. Like the vacuum processing chamber, the transfer chamber is normally kept in a vacuum state. In order to transfer objects to be processed between the transfer chamber in vacuum state and the outside of the vacuum processing system in atmospheric pressure state, a vacuum preparation chamber (load lock chamber) capable of switching between vacuum state and atmospheric pressure state is provided. The transfer chamber communicates with the vacuum preparation chamber through an opening for loading and unloading the object to be processed. A gate valve (gate valve) is installed in the opening, so that the transfer chamber and the vacuum preparation chamber are blocked. That is, in the state where the vacuum preparation chamber is switched to atmospheric pressure, the airtightness between it and the transfer chamber in the adjacent vacuum state is ensured by the gate valve.

The gate valve is opened and closed by the pressure of the operating air supplied from the air supply source (air compressor) of the factory equipped with the vacuum processing system. Specifically, the gate valve uses the pressure of the operating air to resist the pressure difference between it and the vacuum preparation chamber in the atmospheric pressure state, and maintains the transfer chamber in a vacuum state. Therefore, if the power consumption of the factory drops or stops due to a power outage, and the air supplied from the air supply source becomes insufficient, the pressure of the operating air will drop, and the gate valve will suddenly open due to the pressure difference. . If the gate valve is suddenly opened, air will rapidly flow into the transfer chamber, causing damage to the object to be processed and members in the transfer chamber.

Contents of the invention

In the vacuum processing system, a pressure switch and a pressure sensor are also provided on the air supply path that operates the gate valve in order to detect the shortage and stop of the air supply from the air supply source. However, since the pressure sensor and the pressure switch detect a drop in air pressure based on an electric signal, there is a problem that they cannot be used, for example, when the power supply is stopped due to a power failure.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide a vacuum device capable of preventing the gate valve from suddenly opening even when the supply of air for operating the gate valve in the vacuum chamber is insufficient.

The vacuum device of the present invention includes a gate valve operated by an operating gas supplied from a gas supply source, and a vacuum chamber maintained in a vacuum state by the gate valve. The vacuum device has: a communication hole formed through the wall of the vacuum chamber to introduce external air into the vacuum chamber; one end side is connected to the communication hole, and a pipe for vacuum leakage is formed on the other end side; The piping is opened and closed by the first control gas to switch the introduction of the outside air from the vacuum leak port. The first opening and closing mechanism operates when the supply pressure of the first control gas becomes It is opened when the pressure is lower than a predetermined pressure, and outside air is introduced into the vacuum chamber from the vacuum leak port. The vacuum device of the present invention may further include a check valve in the middle of the supply path of the operating gas from the gas supply source to the gate valve.

In addition, in the vacuum device of the present invention, the first control gas may be supplied through a supply path branched from the supply path of the operating gas at a position closer to the gas supply source than the check valve. , and it is the gas of the same system as the above-mentioned gas for action.

The vacuum device of the present invention may further include a buffer tank for preliminarily storing the operating gas in the vacuum device at a position closer to the gate valve than the check valve in the supply path of the operating gas.

The vacuum device of the present invention may further include an opening and closing control unit that controls opening and closing of the first opening and closing mechanism, and the opening and closing control unit includes: switching supply or blocking of the first control gas to the first opening and closing mechanism. The second opening and closing mechanism that is disconnected; and the actuator for switching the second opening and closing mechanism by using the second control gas that is in the same system as the above-mentioned operating gas, and the actuator is in the above-mentioned first 2. When the supply pressure of the control gas falls below a predetermined pressure, the second opening and closing mechanism is switched to block the supply of the first control gas to the first opening and closing mechanism.

In the vacuum device according to the present invention, the opening/closing control unit may further include an urging member provided between the actuator and the second opening/closing mechanism for adjusting switching timing of the second opening/closing mechanism using an urging force.

In the vacuum apparatus of the present invention, an inert gas supply source may be connected to the above-mentioned vacuum leak port.

The vacuum processing system of the present invention is a vacuum processing system for performing predetermined processing on an object to be processed in a vacuum state, and includes the vacuum device described above.

In the vacuum processing system of the present invention, the vacuum chamber may be a vacuum transfer chamber for transferring the object to be processed to a vacuum processing chamber for performing a predetermined process on the object to be processed. Alternatively, the vacuum chamber may be a vacuum preparation chamber that can be switched between an atmospheric pressure release state and a vacuum state for loading and unloading an object to be processed into and out of the vacuum processing system.

The vacuum processing system of the present invention may be a plasma processing system for performing plasma processing on an object to be processed.

The pressure control method of a vacuum chamber of the present invention is a method for controlling the pressure of the vacuum chamber in a vacuum device having a gate valve operated by an operating gas supplied from a gas supply source, and a vacuum chamber maintained in a vacuum state by the gate valve. A pressure control method for a controlled vacuum chamber. In the method for controlling the pressure of a vacuum chamber according to the present invention, the vacuum device includes: a communication hole for introducing external air into the vacuum chamber; a pipe having one end connected to the communication hole and forming a vacuum leak port at the other end; The piping is opened and closed by the first control gas to switch the introduction of the outside air from the vacuum leak port; and the supply of the operating gas from the gas supply source to the gate valve is provided. The check valve in the middle of the path is opened to prevent the reverse flow of the operating gas by the check valve when the pressure of the operating gas supplied from the gas supply source drops while the vacuum chamber is evacuated. The first opening/closing mechanism introduces outside air into the vacuum chamber from the vacuum leak port to bring the pressure of the vacuum chamber close to atmospheric pressure.

In the pressure control method of the vacuum chamber of the present invention, in the supply path of the above-mentioned operation gas, a buffer tank for storing the above-mentioned operation gas in advance is provided at a position closer to the gate valve than the above-mentioned one-way valve, so as to ensure the above-mentioned pressure. Action gas.

In the method for controlling the pressure of a vacuum chamber according to the present invention, the first control gas is a gas of the same system as the operating gas, and is used from a position closer to the gas supply source than the one-way valve from the operating gas. When the supply path of the gas is branched, the supply path is supplied; when the supply pressure of the first control gas becomes equal to or lower than a predetermined pressure, the first opening and closing mechanism is opened to introduce external air from the vacuum leak port to the vacuum chamber. .

In the pressure control method of the vacuum chamber of the present invention, the vacuum device further includes an opening and closing control unit that controls the opening and closing of the first opening and closing mechanism, and the opening and closing control unit includes: switching the opening and closing of the first opening and closing mechanism. A second opening and closing mechanism for supplying or blocking the first control gas; and an actuator for switching the second opening and closing mechanism by operating with the second control gas in the same system as the operating gas When the supply pressure of the second control gas is below a predetermined pressure, the actuator is switched to block the supply of the first control gas to the first opening and closing mechanism, and the first opening and closing mechanism is opened. The closing mechanism is used to introduce external air into the vacuum chamber from the vacuum leak port.

In the pressure control method of the vacuum chamber of the present invention, an urging member may be provided between the actuator and the second opening and closing mechanism, and the switching timing of the second opening and closing mechanism may be adjusted by the urging member.

In the method for controlling the pressure of a vacuum chamber according to the present invention, the outside air introduced from the vacuum leak port may be an inert gas.

According to the vacuum device of the present invention, when the supply of gas such as air from the gas supply source is stopped, the first opening and closing mechanism can be opened, and then the outside air can be gradually introduced into the vacuum chamber through the vacuum leak port. Therefore, the pressure difference between the inside and outside of the vacuum chamber maintained in a vacuum state by the gate valve is reduced, and it is possible to prevent the gate valve from suddenly opening. Therefore, it has the effect of preventing the object to be processed and mechanical materials in the vacuum chamber from being damaged due to sudden opening of the gate valve.

In the vacuum apparatus of the present invention, the opening and closing of the first opening and closing mechanism is controlled by the first control gas. Therefore, since the opening and closing of the first opening and closing mechanism does not require electric power, the function of the first opening and closing mechanism can be exhibited even when the supply of operating air is stopped due to a power failure or the like. In this regard, the present invention is more preferable than the case of using electrical devices such as a pressure sensor and a pressure switch that cannot operate when the power supply is stopped.

Description of drawings

FIG. 1 is a schematic perspective view of a vacuum processing system.

FIG. 2 is a plan view of the vacuum processing system of FIG. 1 .

Fig. 3 is a cross-sectional view showing an open state of the gate valve.

Fig. 4 is a sectional view showing a closed state of the gate valve.

Fig. 5 is a schematic diagram illustrating the structure of the pressure control mechanism according to the first embodiment of the present invention.

Fig. 6 is a schematic diagram illustrating the structure of a pressure control mechanism according to a second embodiment of the present invention.

Fig. 7 is a schematic diagram illustrating an open state of a mechanical valve.

Fig. 8 is a schematic diagram illustrating a closed state of the mechanical valve.

FIG. 9 is a schematic diagram illustrating a structural example of a pressure control mechanism according to a third embodiment of the present invention.

10 is a schematic diagram illustrating another structural example of the pressure control mechanism according to the third embodiment of the present invention.

susceptor symbol description

1a, 1b, 1c, processing chamber 2, base 3, transfer chamber

5. Load lock chamber 7b, gate valve 47, cylinder 100 vacuum treatment system

101. Air supply piping 103. Check valve 105. Buffer tank

107. Communication hole 109. Vacuum leak port 111. Gas introduction piping

113. Pneumatic valve 115. Air piping for control 121. Mechanical valve

123. Cylinder 125. Spring 127. Atmospheric opening

131, _N2 supply source 300, air supply source S, substrate

Detailed ways

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Here, a substrate processing system including the vacuum apparatus according to the first embodiment of the present invention will be described as an example. FIG. 1 is a schematic perspective view of a vacuum processing system 100 as a substrate processing system, and FIG. 2 is a schematic plan view of the interior with lids (not shown) of each chamber opened. The vacuum processing system 100 forms a multi-chamber configuration having several processing chambers 1a, 1b, 1c. The vacuum processing system 100 constitutes, for example, a plasma processing system that performs plasma processing on a glass substrate (hereinafter referred to simply as "substrate") S for FPD. In addition, examples of the FPD include a liquid crystal display (LCD), an organic electroluminescence (EL) display, a plasma display panel (PDP), and the like.

In the vacuum processing system 100, several large chambers are connected in a cross shape. The transfer chamber 3 is disposed in the center, and three processing chambers 1a, 1b, and 1c for performing plasma processing on the substrate S are disposed adjacent to three side surfaces thereof. In addition, a load lock chamber 5 is arranged adjacent to the other side of the transfer chamber 3 . The three processing chambers 1a, 1b, 1c, the transfer chamber 3, and the load lock chamber 5 all constitute a vacuum chamber. Openings (not shown) are provided between the transfer chamber 3 and the respective processing chambers 1a, 1b, and 1c, and gate valves 7a having an opening and closing function are respectively arranged at the openings. In addition, a gate valve 7 b is disposed between the transfer chamber 3 and the load lock chamber 5 . The gate valves 7 a and 7 b airtightly seal between the respective chambers in the closed state, and allow the chambers to communicate with each other in the open state, so that the substrate S can be transported. A gate valve 7 c is also provided between the load lock chamber 5 and the outside atmosphere. When closed, the airtightness of the load lock chamber 5 is maintained, and when opened, the substrate S can be transferred between the inside and outside of the load lock chamber 5 .

Outside the load lock chamber 5 are provided two cartridge indexers 9a, 9b. Cassettes 11a, 11b accommodating the substrate S are placed on the respective cassette indexers 9a, 9b, respectively. In each case 11a, 11b, the board|substrate S is arrange|positioned in multiple layers at intervals in the vertical direction. Each cassette 11a, 11b can be freely raised and lowered by the elevating mechanism part 13a, 13b, respectively. In this embodiment, for example, unprocessed substrates S are accommodated in the cassette 11a, and processed substrates S are accommodated in the other cassette 11b.

A transfer device 5 for transferring the substrate S is provided between the two cassettes 11a, 11b. The conveying device 5 includes a forklift 17a and a forklift 17b as substrate holders arranged in two stages up and down, an operating part 19 that supports the forklift 17a and the forklift 17b so as to be able to move in and out, withdraw and rotate, and a support stand that supports the operating part 19. twenty one.

The processing chambers 1a, 1b, and 1c are configured such that their internal spaces can be maintained in a predetermined reduced-pressure atmosphere (vacuum state). As shown in FIG. 2 , a susceptor 2 as a mounting table on which the substrate S is mounted is provided in each of the processing chambers 1 a , 1 b , and 1 c. In each of the processing chambers 1a, 1b, and 1c, with the substrate S placed on the susceptor 2, various plasmas such as etching, ashing, and film formation are performed on the substrate S under vacuum conditions, for example. body processing.

In this embodiment, the same type of processing may be performed in the three processing chambers 1a, 1b, and 1c, or different types of processing may be performed in each processing chamber. Furthermore, the number of processing chambers is not limited to three, and may be more than four.

The transfer chamber 3 is a vacuum chamber adopting a structure capable of maintaining a predetermined reduced pressure atmosphere, similarly to the processing chambers 1a to 1c which are vacuum processing chambers. As shown in FIG. 2 , a transport device 23 is arranged in the transport chamber 3 . The transport device 23 includes a comb-tooth-shaped forklift 25 that can rotate, move in and out, and retreat to transport the substrate S. As shown in FIG. The substrate S is transferred between the three processing chambers 1 a , 1 b , and 1 c and the vacuum lock 5 by the transfer device 23 . The conveyance device 23 is provided with the conveyance mechanism provided in two upper and lower stages, and these can carry in and carry out the board|substrate S independently, respectively.

The load lock chamber 5 serving as a vacuum spare chamber has a structure capable of maintaining a predetermined reduced pressure atmosphere similarly to the processing chambers 1 a to 1 c and the transfer chamber 3 . The load lock chamber 5 is used to transfer the substrate S between the cassettes 11a and 11b in the atmospheric pressure state and the transfer chamber 3 in the reduced pressure state. Since the load lock chamber 5 repeats the atmospheric pressure state and the depressurized state, the volume configuration is made as small as possible. In the load lock chamber 5 , substrate storage portions 27 are provided in upper and lower stages (only the upper stage is shown in FIG. 2 ), and a plurality of buffers 28 for supporting the substrate S are provided in each substrate storage portion 27 at intervals. The intervals between these buffers 28 serve as clearance grooves for a comb-shaped forklift (for example, the forklift 25 ). In addition, in the load lock chamber 5 , a positioner 29 is provided in contact with the vicinity of the facing corner of the rectangular substrate S for positioning.

As shown in FIG. 2 , each component of the vacuum processing system 100 is connected to and controlled by a control unit 30 (not shown in FIG. 1 ). The control unit 30 has a controller 31 including a CPU, a user interface 32 , and a storage unit 33 . The controller 31 overall controls, for example, each component of the vacuum processing system 100 , the processing chambers 1 a to 1 c , the transfer device 15 , the transfer device 23 , and the like. The user interface 32 is composed of a keyboard through which a process manager performs command input operations for managing the vacuum processing system 100, a display showing the operation status of the vacuum processing system 100, and the like. In the storage unit 33 , strategies are stored which record control programs (software) and processing condition data for realizing various processes executed in the vacuum processing system 100 under the control of the controller 31 . The user interface 32 and the storage unit 33 are connected to the controller 31 .

And, according to the need, according to the instructions issued from the user interface 32, etc., read any strategy from the storage unit 33, and then run it in the controller 31, and then under the control of the controller 31, implement all strategies in the vacuum processing system 100. hoped for treatment.

As the strategies for the control program and processing condition data described above, strategies stored in a computer-readable storage medium such as CD-ROM, hard disk, floppy disk, flash memory, etc. may be used. Alternatively, the policy described above can be used online at any time from another device, for example via a dedicated line.

Next, the operation of the vacuum processing system 100 configured as described above will be described.

First, the two forklifts 17a, 17b of the transport device 15 are driven forward and backward, the substrate S is taken from the cassette 11a containing unprocessed substrates, and placed in the buffers of the substrate storage parts 27 in the upper and lower stages of the load lock chamber 5, respectively. device 28.

After the forklifts 17a and 17b are moved back, the gate valve 7c on the atmospheric side of the load lock chamber 5 is closed. Thereafter, the inside of the load lock chamber 5 is evacuated, and the inside thereof is depressurized to a predetermined vacuum degree. Next, the gate valve 7b between the transfer chamber 3 and the load lock chamber 5 is opened, and the substrate S accommodated in the substrate storage portion 27 of the load lock chamber 5 is picked up by the forklift 25 of the transfer device 23 .

Next, the substrate S is carried into any one of the processing chambers 1 a , 1 b , and 1 c by the forklift 25 of the transfer device 23 , and placed on the susceptor 2 . Next, predetermined processing such as etching is performed on the substrate S in the processing chambers 1a, 1b, and 1c. Then, the processed substrate S is delivered from the susceptor 2 to the forklift 25 of the transport device 23, and carried out from the processing chambers 1a, 1b, and 1c.

The substrate S passes through the load lock chamber 5 in the reverse route to the above, and is accommodated in the cassette 11 b by the transport device 15 . Furthermore, the processed substrate S may be returned to the original cassette 11a.

Next, the structure and operation of the gate valve 7b disposed between the transfer chamber 3 and the load lock chamber 5 will be briefly described with reference to FIGS. 3 and 4 . The gate valve 7 b opens and closes the substrate loading and unloading port 5 b provided on the side wall 5 a of the load lock chamber 5 from the transfer chamber 3 side. Here, the gate valve 7b, and the transfer chamber 3 which is a vacuum chamber maintained in a vacuum state by the gate valve 7b constitute the vacuum apparatus of the present embodiment. In order to be able to close the substrate loading and unloading port 5b capable of loading and unloading the substrate S in a horizontal posture, the gate valve 7b has a horizontally long valve body 41, links 43a, 43b supporting the valve body 41, and connecting rods 43a, 43b to the valve. The horizontally long movable block 45 connected to the body 41 can be raised and lowered. The connecting rods 43a, 43b are respectively bridged between the left side of the movable block 45 and the left side of the valve body 41, and between the right side of the movable block 45 and the right side of the valve body 41 (in addition, In Fig. 3 and Fig. 4, only the links 43a, 43b) on the left side are shown.

The gate valve 7 b includes a cylinder 47 for providing a driving force for vertically displacing the movable block 45 , and a guide rail 49 arranged in the vertical direction for guiding the movable block 45 . A stopper 51 is provided at an upper end portion of the guide rail 49 to come into contact with the upper surface of the movable block 45 to stop the movable block 45 . In addition, a rotating body (roller 55 ) for avoiding friction with the top portion 53 is provided on the upper surface of the valve body 41 .

The movable block 45 is connected to the piston 47a of the air cylinder 47, and is displaced up and down according to the advance and retreat of the piston 47a. Then, the movable block 45 is guided to slide on the vertically arranged guide rails 49 . That is, when the cylinder 47 is actuated to move the piston 47a up and down, and retreats, the movable block 45 moves up and down in the vertical direction under the guidance of the guide rail 49 . Therefore, the valve body 41 connected to the piston 47a is also displaced up and down by the movable block 45 and the connecting rods 43a and 43b, thereby closing or unblocking the substrate loading and unloading port 5b. When the gate valve 7b is opened, as shown in FIG. 3 , the valve body 41 is at a standby position lower than the substrate loading and unloading port 5b, and the movable block 45 is at a standby position lower than the valve body 41 .

When the gate valve 7b is closed from the open state shown in FIG. 3, the cylinder 47 is operated and the piston 47a is advanced (raised) by a predetermined stroke. Then, as shown in FIG. 4 , the movable block 45 and the valve body 41 vertically rise from their original positions parallel to each other, the roller 55 of the valve body 41 contacts the top surface 53 , and then the movable block 45 contacts the stopper 51 . Then, the link rods 43a and 43b are operated to push the valve body 41 toward the substrate loading and unloading port 5b, and push it to the periphery (side wall) of the substrate loading and unloading port 5b. In this operation, the roller 55 moves in the horizontal direction on the top surface 53, and thus, the valve body 41 smoothly moves horizontally. Since a sealing member (not shown) such as an O-ring is attached around the substrate loading/unloading port 5b, the valve body 41 has high airtightness and can seal the substrate loading/unloading port 5b. When the gate valve 7b is in the closed state, the inside of the load lock chamber 5 is in an atmospheric pressure state, and the transfer chamber 3 is in a vacuum state. That is, the valve body 41 seals the substrate carry-in/out port 5b from the vacuum side against the atmospheric pressure.

When the gate valve 7b is opened from the closed state shown in FIG. 4, the cylinder 47 is operated and the piston 47a descends with the same stroke as when it was closed. As a result, the movable block 45 and the valve body 41 return to their original standby positions by the opposite operation to the closing process, and the sealing of the substrate loading and unloading port 5b is released.

The cylinder 47 that drives the gate valve 7b to open and close operates with operating air supplied from an air supply source that is a part of the power of the entire factory in which the vacuum processing system 100 is installed. The air supply source is distributed not only to the gate valve 7 b but also to other devices within the vacuum processing system 100 and external systems. Therefore, if the supply of operating air is stopped or reduced due to any situation such as a sudden increase in air demand in the factory, a power outage, or a failure of the air compressor, the closed state of the gate valve 7b may not be maintained.

If the supply of air for the operation of the drive cylinder 47 is stopped or reduced, the valve body 41 and the movable block 45 cannot withstand the pressure of atmospheric pressure, and the valve body 41 is separated from the substrate loading and unloading port 5b. At the same time, the movable block 45 descends, and the substrate The loading/unloading port 5b is opened. Next, air is abruptly introduced into the vacuum transfer chamber 3 from the atmospheric pressure load lock chamber 5 . The impact caused by the above-mentioned sudden pressure fluctuation and air inflow is sufficient to damage the substrate S and the transfer device 23 in the transfer chamber 3 .

FIG. 5 shows the structure of the pressure control mechanism 200 in the vacuum processing system 100 of this embodiment. In the vacuum processing system 100, the pressure control mechanism 200 is provided to prevent the gate valve 7b from suddenly opening when the supply of operating air supplied from the air supply source 300 is stopped or dropped. The pressure control mechanism 200 will be described with reference to FIG. 5 .

When the operating air supplied from the air supply source 300 is notified to be supplied or lowered, the pressure control mechanism 200 keeps the gate valve 7b in a closed state for a predetermined time, and at the same time increases the pressure in the transfer chamber 3 on the vacuum side to reduce its impact. The pressure difference in the load lock chamber 5. The pressure control mechanism 200 has: a check valve 103 connected to the gate valve 7b and provided on the air supply pipe 101 that supplies operating air from the air supply source 300 to the cylinder 47 of the gate valve 7b; The buffer tank 105 on the air supply piping 101 on the downstream side of the air supply direction.

In addition, the pressure control mechanism 200 has: a communication hole 107 attached to the transfer chamber 3 and formed through the wall of the transfer chamber 3 (for example, the bottom wall 3a); one end is connected to the communication hole 107, and the other end has a vacuum leak port 109. A gas introduction pipe 111 of a narrow flow path; and a pneumatic valve 113 as a first opening and closing mechanism for opening and closing the flow path of the gas introduction pipe 111 . The pneumatic valve 113 is connected to the control air pipe 115 , and the opening and closing of the pneumatic valve 113 is controlled by the first control air supplied through the control air pipe 115 as the first control gas.

The check valve 103 provided on the air supply pipe 101 prevents air from flowing from the gate valve 7b side of the relatively positive pressure to the negative pressure when, for example, the air supply source 300 stops working due to a power failure or the like and the supply of air for operation is cut off. The air supply source 300 side flows backwards. In addition, a buffer tank 105 storing a predetermined amount of air is provided on the downstream side of the air supply path of the check valve 103, thereby ensuring the amount of air required to continue driving the cylinder 47 of the gate valve 7b for a predetermined time. Thus, the check valve 103 and the buffer tank 105 function to cooperate with each other to secure operating air when the supply of operating air from the air supply source 300 is cut off, and to maintain the gate valve 7b as long as possible. Sealed state. Therefore, for example, when the supply of operating air from the air supply source 300 stops for a short time, the check valve 103 can be used to prevent the reverse flow of air, and at the same time, the operating air stored in the buffer tank 105 can be used to maintain the air flow. The sealing state of the gate valve 7b.

Next, actions of the communication hole 107 provided in the transfer chamber 3, the gas introduction pipe 111, and the pneumatic valve 113 will be described. The communication hole 107 is a through hole formed in the bottom wall 3 a of the transfer chamber 3 . Furthermore, the through hole 107 may also be formed in the side wall of the transfer chamber 3 . The communication hole 107 is connected to a gas introduction pipe 111 .

The gas introduction pipe 111 has a narrow flow path and has a large flow path resistance. A pneumatic valve 113 is arranged in the middle of the gas introduction pipe 111 . In addition, a vacuum leak port 109 for introducing external air is formed at the other end of the gas introduction pipe 111 . That is, the communication hole 107 is connected to the vacuum leak port 109 via the gas introduction pipe 111 , and the flow formed by the gas introduction pipe 111 is controlled to be opened and closed by the pneumatic valve 113 .

The pneumatic valve 113 is a normally open valve, and operates by the first control air supplied through the control air pipe 115 . The pneumatic valve 113 maintains a closed state while the supply of the first control air supplied through the control air pipe 115 is equal to or higher than a predetermined pressure. The air pipe 115 for control is a branch of the air supply pipe 101 which supplies the operation air of the cylinder 47 which drives the gate valve 7b. That is, the first air for control and the air for operation are air of the same system supplied from the same air supply source 300 . The control air pipe 115 is branched from the air supply pipe 101 on the upstream side of the check valve 103 in the air supply direction.

As described above, the first control air supplied from the control air pipe 115 is the air of the same system as the operating air of the cylinder 47 that drives the gate valve 7b. Therefore, during the supply of the operating air, the first control air The supply also continues. However, if the operation air supplied from the air supply source 300 stops or decreases due to, for example, a power outage, etc., the supply of the first control air also stops or decreases. The pneumatic valve 113 is switched to an open state when the above-mentioned first control air becomes lower than a predetermined pressure, for example, 0.1 MPa or lower.

When the pneumatic valve 113 is opened, it is known that the inside of the transfer chamber 3 is in a communication state from the vacuum leak port 109 through the gas introduction pipe 111 and the communication hole 107 . The gas introduction pipe 111 is set to have a large flow path resistance. For example, set in the following manner, when the volume of the transfer chamber 3 is 12 cubic meters, and the internal pressure is 1 Pa in vacuum, when the pneumatic valve 113 is opened, the transfer chamber 3 becomes atmospheric pressure within approximately 1.5 to 2 hours. .

As described above, when the supply of air from the air supply source 300 is stopped or reduced due to a power failure or the like, the pneumatic valve 113 is opened, and external air such as the atmosphere passes through the vacuum leak port 109, the gas introduction pipe 111, and the communication hole 107. Gradually flow into the transfer chamber 3 in a vacuum state. Next, due to the introduction of external air, the pressure in the vacuum state transfer chamber 3 gradually approaches atmospheric pressure, so the pressure applied to the valve body 41 of the gate valve 7b from the atmospheric pressure load lock chamber 5 side is gradually relaxed.

As described above, in the present embodiment, when the supply of air from the air supply source 300 stops, the check valve 103 and the buffer tank 105 can secure the air necessary for maintaining the current closed state of the gate valve 7b ( That is, the air required to drive the cylinder 47). In this state, the pneumatic valve 113 connected to the transfer chamber 3 is opened, and the external air is gradually introduced into the transfer chamber 3 in a vacuum state from the narrow gas introduction pipe 111 with a large flow path impedance. The pressure difference between the transfer chambers 3 is relaxed, and it is possible to prevent the gate valve 7b from suddenly opening. Therefore, even when the supply of operating air for operating the gate valve 7b is stopped, damage to the substrate S and the transfer device 23 caused by the sudden opening of the gate valve 7b can be prevented.

In addition, the pressure control mechanism 200 controls the opening and closing of the pneumatic valve 113 using the first control air of the same system (same air supply source 300) as the operating air of the gate valve 7b, and is a mechanism that does not use electricity. Therefore, even when the supply of operating air is stopped due to a power failure or the like, the pressure control mechanism 200 can function. From this point of view, the pressure control mechanism 200 is superior to the case where the air supply pipe 101 includes electrical mechanisms such as a pressure sensor and a pressure switch that cannot be operated when the power supply is stopped.

In FIG. 5 , a buffer tank 105 is provided on the air supply pipe 101 on the downstream side of the check valve 103 in the air supply direction. However, the buffer tank 105 may not be provided when sufficient air to keep the gate valve 7b closed for a predetermined time can be ensured only by the air supply pipe 101 between the check valve 103 and the cylinder 47 .

(second embodiment)

Next, a pressure control mechanism 201 according to a second embodiment of the present invention will be described with reference to FIGS. 6 to 8 . FIG. 6 shows the structure of the pressure control mechanism 201 of this embodiment. This pressure control mechanism 201 is the same as the pressure control mechanism 200 of the first embodiment, and can also be applied to the vacuum processing system 100 . Therefore, here, differences from the first embodiment will be mainly described. In FIGS. 6 to 8 , the same structures as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

The pressure control mechanism 201 has a check valve 103 connected to the gate valve 7b and provided on the air supply pipe 101 for supplying operating air from the air supply source 300 to the cylinder 47 of the gate valve 7b; The buffer tank 105 on the downstream side of the air supply direction.

The pressure control mechanism 201 has a communication hole 107 attached to the transfer chamber 3 and provided on the bottom wall 3a of the transfer chamber 3; one end is connected to the communication hole 107, and the other end forms a gas introduction port 109 with a narrow flow path for vacuum leakage. piping 111; a pneumatic valve 113 as a first opening and closing mechanism for opening and closing the gas introduction piping 111; a mechanical valve 121 as a second opening and closing mechanism for switching the air flow to the pneumatic valve 113; a cylinder 123 of the actuator; and a spring 125 as a loading member provided between the mechanical valve 121 and the cylinder 123 . The mechanical valve 121 , the air cylinder 123 and the spring 125 function as an opening and closing control unit that controls the opening and closing of the pneumatic valve 113 .

The pneumatic valve 113 is connected to a control air pipe 115 , and the opening and closing of the pneumatic valve 113 is controlled by the first control air supplied through the control air pipe 115 . In the present embodiment, the control air pipe 115 branches midway into a pipe 115 a for supplying the first control air to the mechanical valve 121 and a pipe 115 b for supplying the second control air to the cylinder 123 .

Since the structures and functions of the check valve 103 and the buffer tank 105 are the same as those of the first embodiment, description thereof will be omitted. In addition, the structures and functions of the communication hole 107 and the pneumatic valve 113 are also the same as those of the first embodiment.

7 and 8 show enlarged structural diagrams of the opening and closing control unit. The mechanical valve 121 has a spring 121a, a switch unit 121b for switching ON/OFF by the urging force of the spring 121a, and a three-port valve having three ports A, B, and C. Port A is connected to the pipe 115a. The port B is connected to the pneumatic valve 113 via the pipe 115c. Port C is connected to the atmosphere opening port 127 .

In FIG. 7 , the mechanical valve 121 is "on", indicating a state in which air is supplied to the pneumatic valve 113 through the flow path from port A to port B. In FIG. Port C connected to the atmosphere opening port 127 is closed. In FIG. 8 , the mechanical valve 121 is "OFF", indicating that the port A is closed and the air supply to the pneumatic valve 113 is blocked. The port C connected to the atmosphere opening port 127 is opened, and an air flow path from the port B to the port C is formed.

With the port A of the mechanical valve 121 open, the first control air sent to the pneumatic valve 113 is supplied from the same air supply source 300 as the air for operating the cylinder 47 of the gate valve 7b through the pipes 115a and 115c. .

The cylinder 123 is a drive unit that switches on/off the switch unit 121 b of the mechanical valve 121 . The cylinder 123 is also operated by the second control air as the second control gas supplied from the same air supply source 300 as the operation air for operating the cylinder 47 of the gate valve 7b via the pipe 115b. That is, when air is supplied from the air supply source 300, the piston 123a of the cylinder 123 advances, and as shown in FIG. Then, in the state where air is supplied from the air supply source 300, the switch part 121b of the mechanical valve 121 is always turned on (ON), and the air flows between the ports A and B.

On the other hand, when the supply of air from the air supply source 300 is stopped or the air pressure drops, as shown in FIG. Thus, between the ports A and B of the mechanical valve 121 is blocked.

The spring 125 is provided between the cylinder 123 and the mechanical valve 121 , and finely adjusts the pressing force when the piston 123 a of the cylinder 123 presses the switch portion 121 b of the mechanical valve 121 . The timing at which the switch portion 121b of the mechanical valve 121 is turned off (OFF) while the air pressure supplied to the cylinder 123 is falling can be precisely adjusted by the urging force of the spring 125 . In this embodiment, it is set as follows. For example, when the pressure of the second control air supplied from the air supply source 300 is in the range of about 0.35 to 0.4 MPa, the piston 123a of the cylinder 123 moves backward, and the mechanical valve The switch part 121b of 121 is switched to OFF (OFF). Therefore, the function of the spring 125 is to switch the mechanical valve 121 within the required pressure range. That is, the spring 125 has the function of a valve switching timing adjustment mechanism, which performs fine adjustment so that when the pressure of the second control air is within a predetermined range, the mechanical valve 121 is turned on/off (in other words, the pneumatic valve 113 is switched on and off). switch.

From the state shown in FIG. 7 , when the air supplied to the cylinder 123 stops or drops to a predetermined pressure, as shown in FIG. 8 , the ports A and B of the mechanical valve 121 are blocked. Then, the pneumatic valve 113 is opened, and external air (for example, air) gradually flows into the transfer chamber 3 in a vacuum state through the vacuum leak port 109 , the gas introduction pipe 111 with a large flow path resistance, and the communication hole 107 . By introducing external air through the communication hole 107, the pressure in the vacuum state of the transfer chamber 3 gradually approaches the atmospheric pressure, so the pressure applied to the valve body 41 of the gate valve 7b from the side of the load lock chamber 5 in the open state of the atmospheric pressure is gradually eased. This pressure control in the transfer chamber 3 is carried out under the state of ensuring the air for the operation of the cylinder 47 by using the check valve 103 and the buffer tank 105. Even when air is used, sudden opening of the gate valve 7b can be prevented.

In this embodiment, the mechanical valve 121, the cylinder 123, and the spring 125 are provided as an opening and closing control part, and the air valve 113 is controlled to open and close. Therefore, compared with the first embodiment in which only the pneumatic valve 113 is used, there is an advantage that the opening and closing timing of the pneumatic valve 113 can be adjusted with high accuracy by the opening and closing control unit. Furthermore, when the opening and closing timing of the pneumatic valve 113 can be adjusted within a predetermined pressure range by using the mechanical valve 121 and the cylinder 123, the spring 125 may be omitted.

The other structures, operations, and effects of this embodiment are the same as those of the first embodiment. In addition, in this embodiment, the air supplied from the air supply source 300 and the air of a system different from the operation air of the gate valve 7b may be used as 1st air for control.

(third embodiment)

Next, pressure control mechanisms 202a and 202b according to a third embodiment of the present invention will be described with reference to FIGS. 9 and 10 . 9 and 10 show the structure of the pressure control mechanisms 202a and 202b of this embodiment. The pressure control mechanisms 202a and 202b can also be applied to the vacuum processing system 100 similarly to the pressure control mechanisms 200 and 201 of the first and second embodiments. Therefore, differences from the first and second embodiments will be mainly described here. In FIGS. 9 and 10 , the same structures as those of the first embodiment are denoted by the same reference numerals, and description thereof will be omitted.

In the pressure control mechanism 200 of the first embodiment, the vacuum leak port 109 at the end of the gas introduction pipe 111 opened and closed by the pneumatic valve 113 is in an open state to the atmosphere (see FIG. 5 ). On the contrary, in the pressure control mechanism 202a of the present embodiment, as shown in FIG. 9 , the vacuum leak port 109 is connected to the nitrogen (N ₂ ) gas supply source 131 . Therefore, when the supply of air for operation of the cylinder 47 is stopped from the air supply source 300, or the pressure drops to open the pneumatic valve 113, the N ₂ gas supplied from the N ₂ supply source 131 passes through the port 109 for vacuum leakage, the gas The introduction pipe 111 and the communication hole 107 are gradually introduced into the transfer chamber 3 .

N ₂ gas contains almost no moisture, and is generally used as a cleaning gas for vacuum chambers. Connect the vacuum leak port 109 to the _N2 gas supply source 131 in advance, so that when the air of the working gas is supplied from the air supply source 300 again, it is not necessary to perform cleaning of the transfer chamber 3 in advance. 113 is more favorable than the situation of introducing external air. In addition, not limited to N ₂ gas, for example, inert gas such as argon gas, dry air, etc. may be used.

The structure of the present embodiment can also be applied to the pressure control mechanism 201 of the second embodiment shown in FIGS. 6 to 8 . Fig. 10 shows a pressure control mechanism 202b that connects the vacuum leak port 109 to the N ₂ gas supply source 131 in a structure including the mechanical valve 121 as the opening and closing control unit, the cylinder 123, and the spring 125 as in the second embodiment. example of. Also in this case, the same effect as above can be obtained.

The other structures, operations, and effects of this embodiment are the same as those of the first and second embodiments.

The embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, in the above-mentioned embodiment, an example of a substrate processing system targeting an FPD substrate has been described, but it can also be applied to a substrate processing system targeting a semiconductor wafer, for example.

In addition, in the above-mentioned embodiment, the transfer chamber in the vacuum state and the load-lock chamber in the atmospheric pressure release state have been described as examples. However, the pressure control mechanism of the present invention can resist the pressure difference between the two spaces by using an air-operated gate valve. The structure to close the opening can also be used. For example, the pressure control mechanism of the present invention can also be applied to the gate valve 7c (see FIGS. 1 and 2 ) between the load lock chamber in a vacuum state and the external atmospheric pressure.

Claims (17)

1. A vacuum device having a gate valve operated by an operating gas supplied from a gas supply source, and a vacuum chamber maintained in a vacuum state by the gate valve, wherein: have: a communication hole formed through a wall of the vacuum chamber for introducing external air into the vacuum chamber; a pipe having one end connected to the communicating hole and forming a vacuum leak port on the other end; and a first opening and closing mechanism provided in the piping for opening and closing with the first control gas to switch the introduction of the outside air from the vacuum leak port, The first opening and closing mechanism is opened when the supply pressure of the first control gas becomes equal to or lower than a predetermined pressure, and the outside air is introduced into the vacuum chamber from the vacuum leak port. 2. The vacuum device of claim 1, wherein: The vacuum device further includes a check valve in a supply path of the operating gas from the gas supply source to the gate valve. 3. The vacuum device of claim 2, wherein: The first control gas is a gas of the same system as the operating gas, and is branched from the supply path of the operating gas at a position closer to the gas supply source than the check valve. The supply path is supplied. 4. The vacuum device according to claim 2 or 3, characterized in that, The vacuum device further includes a buffer tank for preliminarily storing the operating gas at a position closer to the gate valve than the check valve in the supply path of the operating gas. 5. The vacuum apparatus of claim 1, wherein: The vacuum device further includes an opening and closing control unit that controls opening and closing of the first opening and closing mechanism, The opening and closing control unit has: a second opening and closing mechanism for switching supply or blocking of the first control gas to the first opening and closing mechanism; and An actuator that operates with a second control gas that is in the same system as the operating gas to switch the second opening and closing mechanism, The actuator switches the second opening and closing mechanism to block the first opening and closing mechanism to the first opening and closing mechanism when the supply pressure of the second control gas is equal to or lower than a predetermined pressure. Control gas supply. 6. The vacuum apparatus of claim 5, wherein: The opening/closing control unit further includes an urging member provided between the actuator and the second opening/closing mechanism for adjusting switching timing of the second opening/closing mechanism using an urging force. 7. The vacuum apparatus of claim 1, wherein: An inert gas supply source was connected to the vacuum leak port. 8. A vacuum processing system, which performs prescribed processing on an object to be processed in a vacuum state, characterized in that: A vacuum device according to any one of claims 1 to 7 is provided. 9. The vacuum processing system of claim 8, wherein: The vacuum chamber is a vacuum transfer chamber for transferring an object to be processed to a vacuum processing chamber for performing a predetermined process on the object to be processed. 10. The vacuum processing system of claim 8, wherein: The vacuum chamber is a vacuum preparation chamber that can be switched between an atmospheric pressure release state and a vacuum state for carrying in and out a processing object into and out of the vacuum processing system. 11. The vacuum processing system according to any one of claims 8-10, characterized in that, This is a plasma processing system for performing plasma processing on an object to be processed. 12. A method for controlling the pressure of a vacuum chamber, comprising controlling the vacuum in a vacuum device having a gate valve operated by an operating gas supplied from a gas supply source, and a vacuum chamber maintained in a vacuum state by the gate valve. The pressure control method of the vacuum chamber which controls the pressure of the chamber is characterized in that: The vacuum device has: a communication hole for introducing external air into the vacuum chamber; One end side of the pipe is connected to the communication hole, and the other end side is formed with a port for vacuum leakage; a first opening/closing mechanism provided in the piping for opening and closing with a first control gas to switch introduction of outside air from the vacuum leak port; and a check valve provided in the middle of a supply path of the operating gas from the gas supply source to the gate valve, When the pressure of the operating gas supplied from the gas supply source drops while the vacuum chamber is vacuumed, the check valve prevents the backflow of the operating gas and opens the first valve. The opening and closing mechanism introduces external air into the vacuum chamber through the vacuum leak port, and makes the pressure of the vacuum chamber close to atmospheric pressure. 13. The pressure control method of the vacuum chamber as claimed in claim 12, characterized in that, In the supply path of the operating gas, a buffer tank for storing the operating gas in advance is provided at a position closer to the gate valve than the check valve so as to secure the operating gas. 14. The pressure control method of the vacuum chamber as claimed in claim 12 or 13, it is characterized in that, The first control gas is a gas of the same system as the operating gas, and is supplied by branching from the supply path of the operating gas at a position closer to the gas supply source than the check valve. When the supply pressure of the first control gas is equal to or lower than a predetermined pressure, the first opening and closing mechanism is opened to introduce external air from the vacuum leak port into the vacuum chamber. 15. The pressure control method of the vacuum chamber as claimed in claim 12, characterized in that, The vacuum device further includes an opening and closing control unit that controls opening and closing of the first opening and closing mechanism, The opening and closing control unit has: a second opening and closing mechanism for switching supply or blocking of the first control gas to the first opening and closing mechanism; and An actuator that switches the second opening and closing mechanism by operating with a second control gas that is in the same system as the operating gas, When the supply pressure of the second control gas is below a predetermined pressure, the actuator is switched to block the supply of the first control gas to the first opening and closing mechanism, and the valve is opened. The first opening and closing mechanism is used to introduce outside air into the vacuum chamber from the vacuum leak port. 16. The pressure control method of the vacuum chamber as claimed in claim 15, characterized in that, An urging member is provided between the actuator and the second opening and closing mechanism, and the switching timing of the second opening and closing mechanism is adjusted by the urging member. 17. The pressure control method of the vacuum chamber as claimed in claim 12, characterized in that, The external air introduced from the vacuum leak port is an inert gas.

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