System and method for slit valve control

Abstract

Methods and apparatus for slit valve control are provided. In some embodiments, a slit valve system includes a slit valve body having an opening configured to admit a substrate therethrough, a door in the valve body configured to transition between an open position and a closed position in which the opening is closed, a pneumatic actuator coupled to the door, the pneumatic actuator including a moving member configured to exert a force on the door, and a controller coupled to the pneumatic actuator, the controller configured to control a fluid pressure into the pneumatic actuator based at least on a target actuation time of the door or a target vibration of the door.

Description

Technical Field

[0001] The embodiments of this disclosure generally relate to valve control, such as in a semiconductor substrate processing system, and more specifically, to the control of slit valves. Background Technology

[0002] Semiconductor substrates are typically processed in vacuum processing systems, which include one or more chambers for performing substrate processing operations. During processing, the environment within the chambers is maintained at sub-atmospheric pressure. Each chamber includes a slit valve opening controlled by a slit valve, used to seal the chamber and allow the substrate to be transferred into and out of the chamber.

[0003] Each slit valve may be housed within a port sealed between slit valve openings of adjacent chambers. The port typically houses at least one door, coupled to an actuator for moving the door between an open and closed position. The actuator is typically a pneumatic actuator.

[0004] Generally, the operating speed of the door (between fully closed and open) is important for the throughput of the substrate processing system. However, the inventors have observed that faster door operation can cause the slit valve to be subjected to large shocks or vibrations during opening and closing. These shocks or vibrations can propagate to one or more chambers, potentially loosening and dispersing particles within the chambers, and / or displacing the substrate from its precisely planned position, which could introduce defects on the substrate in subsequent processing operations. Additionally, shocks and vibrations can increase wear on components of the slit valve itself.

[0005] Therefore, the inventors have provided systems and methods for controlling slit valves that can reduce vibration and shock while maintaining throughput. Summary of the Invention

[0006] This document provides methods and apparatus for controlling slit valves. In some embodiments, a slit valve system includes: a slit valve body having an opening configured to allow a substrate to pass through; a door within the valve body configured to switch between an open position and a closed position, in which the opening is closed; a pneumatic actuator coupled to the door, the pneumatic actuator including a moving member configured to apply a force to the door; and a controller coupled to the pneumatic actuator, the controller being configured to control fluid pressure entering the pneumatic actuator based at least on a target actuation time of the door or a target vibration of the door.

[0007] In some embodiments, a substrate processing system includes: a first chamber having a first opening; a second chamber having a second opening; and a slit valve system coupled between the first and second openings, the slit valve system including: a slit valve body having an opening configured to allow a substrate to pass through; a door within the valve body configured to switch between an open position and a closed position, in which the opening is closed; a pneumatic actuator coupled to the door, the pneumatic actuator including a moving member configured to apply force to the door; and a controller coupled to the pneumatic actuator, the controller being configured to control fluid pressure entering the pneumatic actuator based at least on a target actuation time of the door or a target vibration of the door.

[0008] In some embodiments, a method for controlling a slit valve system according to embodiments consistent with this disclosure is described. In some embodiments, the method includes: receiving a target actuation time of the door or a target vibration of the door; determining a pressure control signal based at least on the target actuation time or the target vibration; and controlling the fluid pressure entering a pneumatic actuator based on the determined pressure control signal.

[0009] Other and further embodiments of this disclosure are described below. Attached Figure Description

[0010] The embodiments of this disclosure, which are briefly summarized above and discussed in more detail below, can be understood with reference to the illustrative embodiments depicted in the accompanying drawings. However, the drawings illustrate only typical embodiments of this disclosure and should therefore not be considered as limiting the scope, as other equally effective embodiments are permissible.

[0011] Figure 1 A substrate processing system according to some embodiments of the present disclosure is described.

[0012] Figure 2 A slit valve system according to some embodiments of the present disclosure is described.

[0013] Figure 3 Methods for controlling slit valves according to some embodiments of the present disclosure are described.

[0014] Figure 4 This is a graph of vibration and time versus pressure according to some embodiments of this disclosure.

[0015] To facilitate understanding, the same element symbols have been used to identify common elements across the figures where possible. The figures are not drawn to scale and have been simplified for clarity. Elements and features of one embodiment may be beneficially incorporated into other embodiments without further description. Detailed Implementation

[0016] This document provides embodiments of a substrate processing system and a slit valve system. In some embodiments, and as such... Figure 1 As shown, a substrate processing system 100 is illustrated, comprising a first chamber 102 (e.g., physical vapor deposition (PVD), chemical vapor deposition (CVD), etching, loading lock, or other substrate processing chamber) having a first opening 104 configured to receive a substrate, a second chamber 106 (e.g., a transfer chamber) having a second opening 108 configured to receive a substrate, and a slit valve system 110 hermetically coupled between the first opening 104 and the second opening 108. In some embodiments, such as Figure 1 and Figure 2 As shown, the substrate processing system 100 may include a controller 112 configured to control the operation of the slit valve system 110 based on a target actuation time or a target vibration (measured in g, where 1g equals 9.81 m / s²), thereby reducing shocks and vibrations caused by the operation of the slit valve system 110. As used herein, "target actuation time" refers to the total expected time for the door 138 of the slit valve system 110 to move between an open position and a closed position, and vice versa. Furthermore, as used herein, "target vibration" refers to the maximum expected amount of vibration (measured in g) of the door 138 as it moves between its open and closed positions. As used herein, "vibration" refers to the free vibration that occurs when an object or structure (such as the first chamber 102) is displaced or impacted (e.g., as a result of actuating the slit valve system 110) and then allowed to oscillate naturally.

[0017] In some embodiments, and as Figure 1 As shown, the slit valve system 110 may include a slit valve 111 comprising a slit valve body 130 having an opening 132 configured to allow a substrate to pass through. In some embodiments, the slit valve body 130 may have a first side 134 (at one end of the opening 132) connected to a first opening 104 of a first chamber 102. The slit valve body 130 may have a second side 136 (at the other end of the opening 132) connected to a second opening 108 of a second chamber 106. The slit valve 111 may also include a door 138 in the slit valve body 130. The door 138 may be configured in an open position and a closed position ( Figure 2(as shown) The opening 132 is closed in the closed position to seal the first chamber 102 and prevent the substrate from moving between the first chamber 102 and the second chamber 106.

[0018] In some embodiments, and as Figure 1 As shown, the substrate processing system 100 may further include a third chamber 114 (e.g., physical vapor deposition (PVD), chemical vapor deposition (CVD), etching, loading lock, or other substrate processing chamber), the third chamber having a third opening 116 configured to receive a substrate. In some embodiments, and as shown... Figure 1 As shown, the second chamber 106 may have a fourth opening 118, which is configured to receive a substrate from the third chamber 114 through a slit valve 111 of another slit valve system 110 connected between the third chamber 114 and the second chamber 106. In some embodiments, and as... Figure 1 As shown, the substrate processing system 100 may include a fourth chamber 120 (e.g., physical vapor deposition (PVD), chemical vapor deposition (CVD), etching, loading lock, or other substrate processing chamber) having a fifth opening 122 configured to receive a substrate. In some embodiments, and as shown... Figure 1 As shown, the second chamber 106 may have a sixth opening 128, which is configured to receive a substrate from the fourth chamber 120 through another slit valve 111 of a slit valve system 110 connected between the fourth chamber 120 and the second chamber 106.

[0019] In some embodiments, the substrate transport system 100 may be configured as a clustering tool, wherein the first chamber 102 and the third chamber 114 are processing chambers, the second chamber 106 is a transport / buffer chamber, and the fourth chamber 120 is a loading lock chamber. To enable substrate transport between the first chamber 102, the second chamber 106, the third chamber 114, and the fourth chamber 120, the second chamber 106 may accommodate a robotic transport mechanism (not shown). Illustratively, the transport mechanism may have a pair of substrate transport blades (not shown) respectively attached to the distal ends of a pair of extendable arms (not shown). The substrate transport blades can be used to transport individual substrates into and out of the first chamber 102 and the third chamber 114 (i.e., the processing chamber). Other configurations of transport mechanisms, such as single-blade substrate transport robots, may also be used.

[0020] In operation, one of the substrate transport blades of the transport mechanism removes a substrate from a cassette (not shown) in the fourth chamber 120 (i.e., the loading lock chamber) and transports the substrate to the first processing stage in the first chamber 102, such as physical vapor deposition (PVD). If the first chamber 102 is occupied, the robot waits and holds the substrate in the second chamber 106 (i.e., the transfer / buffer chamber) until processing is complete, and then exchanges the substrate; that is, the processed substrate is removed from the first chamber 102 with one blade, and a new substrate is inserted with a second blade. Before the blade performs the substrate exchange, the door 138 of the slit valve 111 must be opened to allow the blade to enter or exit the first chamber 102 or the third chamber 114 through the opening 132.

[0021] Once the substrate has been processed (e.g., PVD of materials on the substrate), it can be moved to the second processing stage, and so on. During each move, the transport mechanism typically has one blade carrying the substrate, while one blade remains idle to perform substrate exchange. The transport mechanism waits in the first chamber 102 and the third chamber 114 (i.e., the processing chambers) until an exchange can be completed.

[0022] Once processing is complete in the first chamber 102 and / or the third chamber 114, the transport mechanism removes the substrate from the first chamber 102 or the third chamber 114 (e.g., if it is the last processing chamber) and transports the substrate to a cassette (not shown) in the fourth chamber 120.

[0023] As described in more detail below, and with reference to Figure 2 The controller 112 may be configured to receive sensor data from at least one sensor (e.g., first sensor 218, second sensor 220) and to regulate the fluid pressure entering the pneumatic actuator 202 for actuating the door 138 based at least on the sensor data.

[0024] In some embodiments, the controller 112 may include a processor 124 (programmable) that operates in conjunction with a memory 126 and mass storage devices, an input control unit, and a display device (not shown) (such as power supplies, clocks, caches, input / output (I / O) circuitry, and support circuitry 140 for various components coupled to the substrate processing system 100) to facilitate control over them. Support circuitry 140 may be coupled to the processor 124 for conventionally supporting the processor 124.

[0025] Processor 124 may be one of any form of general-purpose computer processor suitable for industrial environments, such as a programmable logic controller (PLC), for controlling various chambers and subprocessors. Memory 126 coupled to processor 124 may be a non-transitory computer-readable storage medium and may be one or more readily available memories, such as random access memory (RAM), read-only memory (ROM), floppy disk drives, hard disks, or any other form of local or remote digital storage device. Fluid flow regulation and other processes described herein are generally stored in memory 126, typically as software routines. Software routines may also be stored and / or executed by a second processor (not shown) remote from the substrate processing system 100 controlled by processor 124.

[0026] Memory 126 may be in the form of a computer-readable storage medium containing instructions that, when executed by processor 124, facilitate the operation of substrate processing system 100. The instructions in memory 126 may be in the form of a program product, such as a program implementing methods according to embodiments of this disclosure. Program code may conform to any of many different programming languages. In one example, this disclosure may be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The program of the program product defines the functionality of the embodiments, including the methods described herein. Illustrative non-transitory computer-readable storage media include, but are not limited to: (i) non-writable storage media that permanently store information (e.g., read-only memory devices within a computer, such as CD-ROM discs readable by a CD-ROM drive, flash memory, ROM chips, or any class of solid-state non-volatile semiconductor memory); and (ii) writable storage media that store changeable information (e.g., floppy disks within a floppy disk drive or hard disk drive, or any class of solid-state random access semiconductor memory). Such non-transitory computer-readable storage media are embodiments of this disclosure when carrying computer-readable instructions that direct the functionality of the methods described herein.

[0027] In some embodiments, and as Figure 2 As shown in more detail, each slit valve 111 may include a pneumatic actuator 202 coupled to a door 138. The pneumatic actuator 202 may include a moving member 204 (e.g., a piston) configured to apply force to the door 138 to move the door 138. The moving member 204 may be connected to the door 138 such that movement of the moving member 204 causes the door 138 to move between an open position and a closed position (e.g., ...). Figure 2 (As shown).

[0028] In some embodiments, and as Figure 2As shown, the slit valve system 110 may include a supply line 206 and an exhaust line 208 coupled to the pneumatic actuator 202. In some embodiments, the supply line 206 may be configured to supply a compressed gas, such as compressed dry air (CDA) or compressed dry nitrogen (CDN), which can be used to actuate the pneumatic actuator 202.

[0029] In some embodiments, the slit valve system 110 may include a switching valve 210 coupled to a supply line 206 and an exhaust line 208 between the controller 212 and the pneumatic actuator 202. In some embodiments, and as... Figure 1 As shown, the pneumatic actuator 202 may have an inlet 214 and an outlet 216 connected to the switching valve 210. The switching valve 210 may be configured to reverse the direction of fluid flow between the inlet 214 and the outlet 216 to reverse the direction of movement of the moving member 204, and thereby reverse the direction of movement of the gate 138.

[0030] Switching valve 210 may have a first position (e.g.) Figure 2 As shown), the first position connects the supply line 206 to the inlet 214 and the exhaust line 208 to the outlet 216. The switching valve 210 may have a second position (not shown) that reverses the flow direction between the inlet and outlet 216, connecting the supply line 206 to the outlet 216 and the exhaust line 208 to the inlet 214. In some embodiments, and as shown... Figure 2 As shown, the switching valve 210 can be communicatively connected to the controller 112. The switching valve 210 can be configured to switch between a first position and a second position based on a position signal 222, which can be generated by the controller 112 or otherwise received from the controller 112.

[0031] In some embodiments, the slit valve system 110 may include a controller 212 ( Figure 2 (Two are shown in the figure), and the controller is coupled to at least one of the supply line 206 or the exhaust line 208. Figure 2 Two controllers 212 are shown, one connected to supply line 206 and the other connected to exhaust line 208. In some embodiments, the two controllers 212 may be combined into one controller 212, which may be coupled to both supply line 206 and exhaust line 208. In some embodiments, controller 212 may be connected to at least one of supply line 206 or exhaust line 208. Controller 212 may be configured as a mass flow controller (such as a flow meter) or a pressure controller (such as a regulator).

[0032] In some embodiments, and as Figure 2As shown, controller 212 can be communicatively connected to each controller 112. Each controller 112 can be configured to receive a pressure control signal 224, which can be generated by or otherwise received from controller 212, and control the fluid pressure entering the pneumatic actuator (entering from inlet 214 or outlet 216 depending on the closing or opening direction). By controlling the fluid pressure entering the pneumatic actuator, the amount of vibration and impact caused by the actuated door 138 can be controlled.

[0033] In some embodiments, controller 212 may be configured to control the fluid pressure entering pneumatic actuator 202 based at least on a target actuation time of door 138 or a target vibration of door 138. As used herein, “target actuation time” refers to the total expected time for door 138 to move between an open position and a closed position, and vice versa. As used herein, “target vibration” refers to the maximum expected amount of vibration (measured in g) as door 138 moves between an open position and a closed position. In some embodiments, the target vibration may be as high as 0.5 g. It has been observed that if the target vibration is set above 0.5 g, vibration transmitted by slit valve system 110 to associated chambers (such as first chamber 102) may result in at least one of unwanted particle generation or unwanted substrate displacement. In some embodiments, the acceptable range of target vibration values ​​may vary depending on the configuration and vibration characteristics of substrate processing system 100. Pressure control signal 224 may include a control pressure setpoint based at least on the target actuation time of door 138 or the target vibration of door 138.

[0034] In some embodiments, and as Figure 2 As shown, the slit valve 111 may include a first sensor 218 configured to sense a first position of the moving member 204, corresponding to an open position of the door 138; and a second sensor 220 configured to sense a second position of the moving member 204, corresponding to a closed position of the door 138. In some embodiments, and as... Figure 2 As shown, controller 112 is communicatively coupled to first sensor 218 and second sensor 220. In some embodiments, controller 112 may be configured to record a first time when first sensor 218 senses a first position and a second time when second sensor 220 senses a second position, and determine the elapsed time between the first and second times. Therefore, the elapsed time is a measurement of the total actuator time of door 138 between the open and closed positions. As described in more detail below, the measured elapsed time can be used as a feedback input to determine the pressure control signal 224 to be supplied to controller 212.

[0035] Figure 3A method 300 for controlling a slit valve according to some embodiments of the present disclosure is illustrated. The slit valve may be a slit valve 111. At block 302, method 300 may include receiving (e.g., at controller 112) a target actuation time or a target vibration. In some embodiments, the target actuation time or target vibration may be input by a user in an interface (e.g., a graphical user interface (GUI)), which may be the interface of controller 112. At block 304, method 300 may include determining (e.g., determined by controller 112) a pressure control signal (e.g., pressure control signal 224) at least based on the target actuation time or target vibration. The pressure control signal may be a pressure control setpoint used by one or more controllers (e.g., controller 212) to control the fluid pressure entering a pneumatic actuator (e.g., pneumatic actuator 202). At block 306, method 300 may include controlling the fluid pressure entering the pneumatic actuator based on a determined pressure control signal (e.g., entering the pneumatic actuator 202 from inlet 214 to close door 138 or entering the pneumatic actuator 202 from outlet 216 to open door 138).

[0036] In some embodiments, the pressure control signal (e.g., pressure control signal 224) may be based on a functional relationship between the target actuation time and the fluid pressure entering the pneumatic actuator 202, or a functional relationship between the target vibration and the pressure entering the pneumatic actuator 202. In some embodiments, the functional relationship between the target actuation time and pressure, and between the target vibration and pressure, may be logarithmic, such as... Figure 4 As shown in one non-limiting example. In some embodiments, and as... Figure 4 As shown, target vibration can be directly proportional to pressure, and target actuation time can be inversely proportional to pressure. For any given system, the relationship between actuation pressure, actuation time, and gate vibration can be determined empirically, and this relationship data is used in conjunction with the method disclosed herein.

[0037] In some embodiments, method 300 may include using a first sensor (e.g., first sensor 218) to sense a first position of a moving member (e.g., moving member 204) corresponding to an open position of the door, and using a second sensor (e.g., second sensor 220) to sense a second position of the moving member corresponding to a closed position of the door, and determining an elapsed time between the first and second positions. In some embodiments, the fluid pressure entering the pneumatic actuator may also be controlled based on the elapsed time. In some embodiments, method 300 may include comparing a target actuation time and an elapsed time, and adjusting a pressure control signal based on the comparison. In some embodiments, and as described above, the target actuation time and target vibration may be functionally correlated with each other by pressure. Therefore, the target actuation time and pressure may correspond to a target vibration at the same pressure. Thus, even if a user inputs a target vibration for controlling the slit valve 111, in some embodiments, the controller 112 may compare the target time corresponding to the target vibration with the elapsed time, rather than comparing the target vibration itself.

[0038] For example, if the target actuation time is four seconds and the elapsed time is five seconds, it can be determined that using the pressure control signal determined at block 304, door 138 is actuated more slowly than expected. In this example, a correction factor can be applied to the pressure control signal determined at block 304 and used at block 306 for the next actuation of door 138. In this example, the correction factor can be based on at least one of the difference between the elapsed time and the target actuation time or the pressure control signal previously determined at block 304, which may have been determined according to the previously discussed functional relationship. In some embodiments, the correction factor can be expressed as a percentage applied to the pressure control signal, such as increasing or decreasing the pressure control signal determined at block 304, thereby increasing or decreasing the elapsed time consistent with the target actuation time.

[0039] The system and method described herein provide slit valve control that can control vibrations and shocks caused by the slit valve actuator. Therefore, particle generation and substrate movement during slit valve operation can be reduced, thereby reducing substrate processing defects and increasing throughput.

[0040] While the foregoing describes embodiments of this disclosure, other and further embodiments of this disclosure may be conceived without departing from the basic scope of this disclosure.

Claims

1. A slit valve system, comprising: A slit valve body having an opening configured to allow a substrate to pass through; A door, located within the valve body, is configured to switch between an open position and a closed position, wherein the opening is closed in the closed position; A pneumatic actuator coupled to the door, the pneumatic actuator including a moving member configured to apply force to the door; as well as A controller coupled to the pneumatic actuator, the controller being configured to control the fluid pressure entering the pneumatic actuator based at least on the target actuation time of the door or the target vibration of the door.

2. The system of claim 1, further comprising: A supply line coupled to the pneumatic actuator; as well as An exhaust line, which is coupled to the pneumatic actuator, The controller is coupled to at least one of the supply line or the exhaust line.

3. The system of claim 2, wherein the controller is connected to at least one of the supply line or the exhaust line.

4. The system of any one of claims 1 to 3, wherein the controller is configured to receive a pressure control signal.

5. The system of claim 2, further comprising a switching valve coupled to the supply line and the exhaust line between the controller and the pneumatic actuator.

6. The system as claimed in any one of claims 1 to 3, further comprising: A first sensor, configured to sense a first position of the movable member corresponding to the open position of the door, and a second sensor, configured to sense a second position of the movable member corresponding to the closed position of the door.

7. The system of claim 6, wherein the controller is configured to control the fluid pressure entering the pneumatic actuator based on the elapsed time between the first sensor detecting the first position and the second sensor detecting the second position.

8. A substrate processing system, comprising: A first chamber, the first chamber having a first opening; A second chamber, the second chamber having a second opening; as well as A slit valve system, coupled between the first opening and the second opening, the slit valve system comprising: A slit valve body having an opening configured to allow a substrate to pass through; A door, located within the valve body, is configured to switch between an open position and a closed position, wherein the opening is closed in the closed position; A pneumatic actuator coupled to the door, the pneumatic actuator including a moving member configured to apply force to the door; and A controller coupled to the pneumatic actuator, the controller being configured to control the fluid pressure entering the pneumatic actuator based at least on the target actuation time of the door or the target vibration of the door.

9. The substrate processing system of claim 1, wherein the slit valve system further comprises: A supply line coupled to the pneumatic actuator; as well as An exhaust line, which is coupled to the pneumatic actuator, The controller is coupled to at least one of the supply line or the exhaust line.

10. The substrate processing system of claim 9, wherein the controller is connected to at least one of the supply line or the exhaust line.

11. The substrate processing system of any one of claims 8 to 10, wherein the controller is configured to receive a pressure control signal.

12. The substrate processing system of claim 9, wherein the slit valve system further includes a switching valve coupled to the supply line and the exhaust line between the controller and the pneumatic actuator.

13. The substrate processing system of any one of claims 8 to 10, wherein the slit valve system further comprises a first sensor configured to sense a first position of the movable member corresponding to the open position of the door, and a second sensor configured to sense a second position of the movable member corresponding to the closed position of the door.

14. The substrate processing system of claim 13, wherein the controller is configured to control the fluid pressure entering the pneumatic actuator based on the elapsed time between the first sensor detecting the first position and the second sensor detecting the second position.

15. A method for controlling a slit valve, the slit valve comprising: A slit valve body having an opening configured to allow a substrate to pass through; A door, located within the valve body, is configured to switch between an open position and a closed position, wherein the opening is closed in the closed position; as well as A pneumatic actuator coupled to the door, the pneumatic actuator including a moving member configured to apply force to the door; as well as The method includes: Receive the target actuation time of the door or the target vibration of the door; The pressure control signal is determined at least based on the target actuation time or the target vibration; and The fluid pressure entering the pneumatic actuator is controlled based on the determined pressure control signal.

16. The method of claim 15, wherein the pressure control signal is based on a functional relationship between target actuation time and pressure or between target vibration and pressure.

17. The method of claim 16, wherein the functional relationship is logarithmic.

18. The method of any one of claims 15 to 17, wherein the slit valve further includes a first sensor configured to sense a first position of the movable member corresponding to the open position of the door, and a second sensor configured to sense a second position of the movable member corresponding to the closed position of the door, and the method further includes sensing an elapsed time between the first position and the second position.

19. The method of claim 18, wherein the fluid pressure entering the pneumatic actuator is controlled based on the elapsed time between the first sensor detecting the first position and the second sensor detecting the second position.

20. The method of claim 19, further comprising: The target actuation time and the elapsed time are compared, and the pressure control signal is adjusted based on the comparison.

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