Patent Publication Number: US-2023160494-A1

Title: Gate valve and driving method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2021-188737 filed on Nov. 17, 2021, the entire contents of which are incorporated herein by reference. 
     BACKGROUND 
     Field 
     Exemplary embodiments of the present disclosure relate to gate valves and driving methods. 
     Description of Related Art 
     Japanese Patent Application Laid-Open No. 2018-10986 describes a gate valve having a valve element that moves between the closing position and the opening position. 
     SUMMARY 
     One exemplary embodiment of the present disclosure provides a gate valve, which opens and closes a first opening of a first chamber in a vacuum processing apparatus. The gate valve includes a valve element configured to open and close the first opening; a drive configured to move the valve element so that the valve element takes at least a closing position, where the valve element closes the first opening, and an opening position, where the valve element opens the first opening; a first gas line connected to the drive; and a second gas line connected to the drive. The drive moves the valve element from the opening position to the closing position by pressure of gas supplied from the first gas line or the second gas line, and holds the valve element at the closing position by pressure of gas supplied from the second gas line. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    schematically illustrates one example of a substrate processing system PS. 
         FIG.  2    schematically illustrates one example of the configuration of a gate valve GV. 
         FIG.  3    schematically illustrates one example of a state of a gate valve GV. 
         FIG.  4    schematically illustrates one example of a state of a gate valve GV. 
         FIG.  5    schematically illustrates one example of a state of a gate valve GV. 
         FIG.  6    schematically illustrates one example of the configuration of a gate valve GV. 
     
    
    
     DETAILED DESCRIPTION 
     The following describes embodiments of the present disclosure. 
     One exemplary embodiment provides a gate valve that opens and closes a first opening of a first chamber in a vacuum processing apparatus. The gate valve includes: a valve element configured to open and close the first opening; a drive configured to move the valve element so that the valve element takes at least a closing position, where the valve element closes the first opening, and an opening position, where the valve element opens the first opening; a first gas line and a second gas line; and a first switching valve that connects one of the first gas line and the second gas line to the drive. The drive moves the valve element from the opening position to the closing position by pressure of gas supplied from the first gas line or the second gas line, and holds the valve element at the closing position by pressure of gas supplied from the second gas line. 
     In one exemplary embodiment, the first switching valve has a normally closed valve that changes a connection as to whether or not to supply gas from the first gas line to the drive; and a normally open valve that changes a connection as to whether or not to supply gas from the second gas line to the drive. 
     In one exemplary embodiment, the drive has an air cylinder that moves the valve element, and the first switching valve changes a connection as to whether the air cylinder is connected to the first gas line or to the second gas line. 
     One exemplary embodiment further includes a third gas line connected to the drive, wherein the drive holds the valve element at the opening position by pressure of gas supplied from the third gas line. 
     One exemplary embodiment further includes a second switching valve that changes a connection as to whether gas is supplied to the first gas line or to the third gas line. 
     In one exemplary embodiment, the gas supplied to the first gas line, the gas supplied to the second gas line, and the gas supplied to the third gas line are compressed air. 
     One exemplary embodiment provides a method for driving a gate valve that opens and closes a first opening of a first chamber in a vacuum processing apparatus. The gate valve includes: a valve element configured to open and close the first opening; a drive configured to move the valve element so that the valve element takes at least a closing position, where the valve element closes the first opening, and an opening position, where the valve element opens the first opening; a first gas line and a second gas line; and a first switching valve that connects one of the first gas line and the second gas line to the drive; and a controller. The driving method includes the drive moving the valve element from the opening position to the closing position by pressure of gas supplied from the first gas line or the second gas line; and the drive holding the valve element at the closing position by pressure of gas supplied from the second gas line. 
     In one exemplary embodiment, the first switching valve has a normally closed valve that changes a connection as to whether or not to supply gas from the first gas line to the drive, and a normally open valve that changes a connection as to whether or not to supply gas from the second gas line to the drive. 
     In one exemplary embodiment, the drive has an air cylinder that moves the valve element, and the first switching valve changes a connection as to whether the air cylinder is connected to the first gas line or to the second gas line. 
     One exemplary embodiment further comprise a third gas line connected to the drive, wherein the drive holds the valve element at the opening position by pressure of gas supplied from the third gas line. 
     One exemplary embodiment further comprises a second switching valve that changes a connection as to whether gas is supplied to the first gas line or to the third gas line. 
     In one exemplary embodiment, the gas supplied to the first gas line, the gas supplied to the second gas line, and the gas supplied to the third gas line are compressed air. 
     The following describes embodiments of the present disclosure in details with reference to the drawings. Like reference numerals designate like elements in the drawings to omit their duplicated descriptions. Unless otherwise specified, positional relationships such as top, bottom, left, and right will be described based on the positional relationships illustrated in the drawings. The accompanying drawings have not necessarily been drawn to scale, and the actual proportions are not limited to the illustrated ones. 
     &lt;Configuration of Substrate Processing System PS&gt; 
       FIG.  1    schematically illustrates the substrate processing system PS according to one exemplary embodiment. The substrate processing system PS includes substrate processing modules PM 1  to PM 6  (hereinafter also collectively referred to as “substrate processing module PM”), a transfer module TM, load-lock modules LLM 1  and LLM 2  (hereinafter also collectively referred to as “load-lock module LLM”), a loader module LM, and load ports LP 1  through LP 3  (hereinafter also collectively referred to as “load port LP”). A controller CT controls each element of the substrate processing system PS to perform predetermined processing on substrates W. 
     The substrate processing module PM performs different types of processing such as etching processing, trimming processing, film-forming processing, annealing processing, doping processing, lithography processing, cleaning processing, and ashing processing on a substrate W within the module. Some of the substrate processing modules PM may be a measurement module, which may measure the thickness of layers formed on a substrate W or the dimensions of patterns formed on a substrate W, for example. 
     The transfer module TM has a conveyer  22  that transfers a substrate W. The transfer module TM transfers a substrate W between the substrate processing modules PM or between one of the substrate processing modules PM and one of the load-lock modules LLM. The substrate processing modules PM and the load-lock modules LLM are disposed adjacent to the transfer module TM. The transfer module TM are spatially isolated from or connected with the substrate processing modules PM or the load-lock modules LLM by openable/closable gate valves GV. In this embodiment, the conveyer  22  (see  FIG.  2   ) in the transfer module TM transfers a substrate W from an interior space  20   s  (see  FIG.  2   ) of a chamber  20  of the transfer module TM to an interior space  10   s  of a chamber  10  (see  FIG.  2   ) of the substrate processing module PM to place the substrate W on a substrate support  11 . The conveyer  22  also transfers a substrate W from the interior space  10   s  of the substrate processing module PM to the interior space  20   s  of the transport module TM. The conveyer  22  moves a substrate W between the transfer module TM and the substrate processing module PM through an opening  12  formed in the chamber  10  of the substrate processing module PM. In one example, the conveyer  22  may be a handler that transfers substrates such as silicon wafers. 
     The load-lock modules LLM 1  and LLM 2  are provided between the transfer module TM and the loader module LM. The load-lock module LLM can change its internal pressure between atmospheric pressure and vacuum. The load-lock module LLM transfers a substrate W from the loader module LM at atmospheric pressure to the transfer module TM in vacuum, or transfers a substrate W from the transfer module TM in vacuum to the loader module LM at atmospheric pressure. 
     The loader module LM has a conveyer that transfers a substrate W to transfer the substrate W between the load-lock module LLM and the load port LP. A front opening unified pod (FOUP) that can store  25  substrates W, for example, or an empty FOUP can be placed inside the load port LP. The loader module LM takes out a substrate W from the FOUP in the load port LP and transfers it to the load-lock module LLM. The loader module LM also takes out a substrate W from the load-lock module LLM and transfers it to the FOUP in the load port LP. 
     The controller CT controls each element of the substrate processing system PS to perform predetermined processing on a substrate W. The controller CT stores recipes, in which process procedures, process conditions, transfer conditions, and the like are set. The controller CT controls each element of the substrate processing system PS to perform predetermined processing on a substrate W in accordance with the recipes. The controller CT may directly or indirectly control each element illustrated in  FIG.  2   . The controller CT may electrically or mechanically control each element illustrated in  FIG.  2   . The mechanical control includes the controlling of each element illustrated in  FIG.  2    using gas. 
     &lt;Configuration of Gate Valve GV&gt; 
       FIG.  2    schematically illustrates the configuration of a gate valve GV according to one exemplary embodiment. The gate valve GV includes a valve element  30 , a drive  40 , switching valves  50 ,  52  and  56 , and gas lines  60 ,  62 ,  64 ,  66  and  68 . The switching valve  50  is an example of a second switching valve. The switching valve  52  is an example of a first switching valve. The gas lines  62 ,  64  and  66  are examples of a first gas line, a second gas line and a third gas line, respectively. 
     The valve element  30  is configured to spatially isolate or connect the interior space  10   s  of the substrate processing module PM and the interior space  20   s  of the transfer module TM. In one example, the valve element  30  is housed in a chamber  34 , which is connected to the chamber  10  of the substrate processing module PM and the chamber  20  of the transfer module TM. The opening  12  is provided to communicate with the chamber  10  to the chamber  34 . The sectional view of the chambers  10 ,  20  and  34  in  FIG.  2    schematically illustrates a part of AA′ cross section in  FIG.  1   . 
     The valve element  30  includes an O-ring  32 . When the valve element  30  presses the O-ring  32  against the inner wall of the chamber  34  around the opening  12 , the interior space  10   s  of the substrate processing module PM and the interior space  20   s  of the transfer module TM are spatially isolated. When the O-ring  32  leaves the inner wall of the chamber  34 , the interior space  10   s  of the substrate processing module PM and the interior space  20   s  of the transfer module TM are spatially connected. 
     The drive  40  is configured to move the valve element  30 . In one example, the drive  40  moves the valve element  30  in the interior space of the chamber  34  in x 1  direction, x 2  direction, z 1  direction, and z 2  direction in  FIG.  2    (hereinafter x 1  direction and x 2  direction may be collectively referred to as “x direction” and z 1  direction and z 2  direction may be collectively referred to as “z direction”). 
     The drive  40  has cylinders  41  and  45 . The drive  40  has a piston  42  inside the cylinder  41 . The piston  42  includes a gasket  43 . The drive  40  also has a shaft  44 . The shaft  44  has one end connected to the piston  42  and the other end connected to the valve element  30 . As the piston  42  moves in z direction inside the cylinder  41 , the valve element  30  moves in z direction inside the chamber  34 . 
     The drive  40  has a piston  46  inside the cylinder  45 . The piston  46  includes a gasket  47 . The drive  40  also has a shaft  48 . The shaft  48  has one end connected to the piston  46  and the other end connected to the shaft  44 . As the piston  46  moves in x direction inside the cylinder  45 , the shaft  44  moves in x direction, so that the valve element  30  moves in x direction inside the chamber  34 . 
     The switching valve  50  has an air supply port and an exhaust port. The gas line  60  is connected to the air supply port of the switching valve  50 . Gas is then supplied from a gas source  70  to the air supply port of the switching valve  50  via a valve  80  and the gas line  60 . The switching valve  50  connects one of the gas lines  62  and  66  to the air supply port to supply gas from the gas source  70  to the connected gas line, and connects the other gas line to the exhaust port to exhaust the gas flowing through the other gas line. In one example, the switching valve  50  may be a solenoid valve. In one example, the gas supplied from the gas source  70  may be compressed air. 
     The switching valve  52  connects one of the gas lines  62  and  64  to the gas line  68 . The gas line  62  is connected to the air supply port or the exhaust port of the switching valve  50 , in accordance with the state of the switching valve  50 . Gas is supplied to the gas line  64  from a gas source  72  via a valve  82 . The valve  82  may be controlled so that gas is constantly supplied from the gas source  72  to the gas line  64  when the switching valve  52  connects the gas line  64  to the gas line  68 . 
     In one example, the switching valve  52  has a pilot port  54 . The switching valve  52  changes its state depending on whether gas is supplied to the pilot port  54  or not. In one example, the switching valve  52  connects the gas line  62  to the gas line  68  when gas is supplied to the pilot port  54 , and connects the gas line  64  to the gas line  68  when gas is not supplied to the pilot port  54 . In one example, the pilot port  54  may be connected to the gas line  66 . That is, the switching valve  52  may connect the gas line  62  to the gas line  68  when gas is supplied from the gas source  70  to the gas line  66 , and may connect the gas line  64  to the gas line  68  when the gas line  66  is connected to the exhaust port of the switching valve  50 . 
     In one example, the gas source  70  may supply gas used in the operation of the transfer module TM. When the gas source  70  supplies gas used in the operation of the transfer module TM, the valve  80  may be closed during maintenance of the transfer module TM. That is, during maintenance of the transfer module TM, the gas is not supplied to the transfer module TM and the pilot port  54 . Thus, the switching valve  52  connects the gas line  64  to the gas line  68 . The drive  40  then receives the gas from the gas source  72 . 
     The gas line  68  is connected to a branch  76  via a valve  88 . The branch  76  branches the gas line  68  to connect it to the cylinders  41  and  45 . When gas is supplied to the gas line  68 , the branch  76  branches the gas supplied to the gas line  68  to supply the gas to the cylinders  41  and  45 . The branch  76  adjusts the pressure and/or flow rate of the gas supplied to the gas line  68  to supply the adjusted gas to the cylinder  41 . The branch  76  also adjusts the pressure and/or flow rate of the gas supplied to the gas line  68  to supply the adjusted gas to the cylinder  45 . 
     The switching valve  56  changes the connection as to whether or not the gas line  66  is connected to the drive  40 . The switching valve  56  has a pilot port  58 . The switching valve  56  connects the gas line  66  to the drive  40  when gas is supplied to the pilot port  58 , and does not connect the gas line  66  to the drive  40  when gas is not supplied to the pilot port  58 . 
     Gas may be supplied to the pilot port  58  from a gas source  74  via a valve  84 . In one example, the gas source  74  may supply gas used in the operation of the substrate processing module PM. When the gas source  74  supplies gas used in the operation of the substrate processing module PM, the valve  84  may be closed during maintenance of the substrate processing module PM. That is, during maintenance of the substrate processing module PM, the gas is not supplied to the substrate processing module PM and the switching valve  56 . Thus, the switching valve  56  is closed, so that the gas line  66  is not connected to the drive  40 . 
     The gas line  66  is connected to the drive  40  via a branch  78 . The branch  78  branches the gas line  66  to connect it to the cylinders  41  and  45 . When gas is supplied to the gas line  66 , the branch  78  branches the gas supplied to the gas line  66  to supply the gas to the cylinders  41  and  45 . The branch  78  adjusts the pressure and/or flow rate of the gas supplied to the gas line  66  to supply the adjusted gas to the cylinder  41 . The branch  78  also adjusts the pressure and/or flow rate of the gas supplied to the gas line  66  to supply the adjusted gas to the cylinder  45 . 
     Referring next to  FIGS.  2  to  5    the following describes one example of the operation of the gate valve GV according to the present embodiment. 
     &lt;Holding Valve Element  30  at Opening Position&gt; 
       FIG.  2    illustrates one example of the state of the gate valve GV when the valve element  30  is at the opening position. As illustrated in  FIG.  2   , when the valve element  30  is held at the opening position, the switching valve  50  connects the gas line  66  to the air supply port of the switching valve  50  and connects the gas line  62  to the exhaust port. With this arrangement, when gas is supplied from the gas source  70  to the gas line  66 , the gas is supplied from the gas line  66  to the pilot port  54  and the switching valve  52  connects the gas line  62  to the gas line  68 . This connects the space in z 2  direction relative to the piston  42  in the interior space of the cylinder  41  and the space in x 2  direction relative to the piston  46  in the interior space of the cylinder  45  to the exhaust port of the switching valve  50 . 
     Gas is then supplied to the space in z 1  direction relative to the piston  42  in the interior space of the cylinder  41  and the space in x 1  direction relative to the piston  46  in the interior space of the cylinder  45  from the gas source  70  via the gas line  66  and the branch  78 . This causes the piston  42  to be pressed in z 2  direction and the piston  46  to be pressed in x 2  direction. Thus, the valve element  30  is held at the opening position illustrated in  FIG.  2   . 
     When the valve element  30  is at the opening position, the position of holding the valve element  30  is not limited to the illustrated position. The valve element  30  may be located so that the interior space  10   s  of the substrate processing module PM and the interior space  20   s  of the transfer module TM are spatially connected. The valve element  30  may be located so that the conveyer  22  can transfer the substrate W to the substrate support  11  through the opening  12 . 
     &lt;Moving Valve Element  30  from Opening Position to Closing Position&gt; 
       FIG.  3    schematically illustrates one example of the state of the gate valve GV when the valve element  30  moves from the opening position to the closing position. When the valve element  30  moves from the opening position to the closing position, the switching valve  50  connects the gas line  66  to the exhaust port of the switching valve  50  and connects the gas line  62  to the air supply port. With this arrangement, gas is not supplied from the gas source  70  to the pilot port  54 . The switching valve  52  then connects the gas line  64  to the gas line  68 . With this arrangement, gas is supplied to the space in z 2  direction relative to the piston  42  in the interior space of the cylinder  41  and the space in x 2  direction relative to the piston  46  in the interior space of the cylinder  45  from the gas source  72 . 
     This connects the space in z 1  direction relative to the piston  42  in the interior space of the cylinder  41  and the space in x 1  direction relative to the piston  46  in the interior space of the cylinder  45  to the exhaust port via the gas line  66 . This causes the piston  42  to be pressed in z 1  direction and the piston  46  to be pressed in x 1  direction. As a result, the valve element  30  moves in z 1  direction and x 1  direction in  FIG.  3   . 
     &lt;Holding Valve Element  30  at Closing Position&gt; 
       FIG.  4    schematically illustrates one example of the state of the gate valve GV when the valve element  30  is at the closing position. After the valve element  30  moves from the opening position in z 1  and x 1  directions to close the opening  12  as illustrated in  FIG.  4   , the switching valves  50  and  52  may continue to assume the same state illustrated in  FIG.  3   . That is, the switching valve  50  may connect the gas line  66  to the exhaust port. The switching valve  52  may connect the gas line  64  to the gas line  68 . This arrangement allows gas to be supplied from the gas source  72  to the cylinders  41  and  45 , even after the valve element  30  moves to the closing position. Thus, after the valve element  30  moves to the closing position, i.e., when the valve element  30  is held at the closing position, the gas supplied from the gas source  72  can give sufficient pressure to the pistons  42  and  46  in z 1  and x 1  directions, respectively, in the cylinders  41  and  45 . This causes the valve element  30  to be pressed against the inner wall of the chamber  34  and spatially isolates the interior space  10   s  of the substrate processing module PM from the interior space  20   s  of the transfer module TM. 
     According to this embodiment, when the valve element  30  is held at the closing position, the gas supplied from the gas source  72  presses the valve element  30  against the inner wall of the chamber  34  while keeping a predetermined pressure. This reduces a gas leakage from the interior space  10   s  to the interior space  20   s  even when the pressure in the interior space  10   s  of the substrate processing module PM is higher than the pressure in the interior space  20   s  of the transfer module TM. 
     &lt;Moving Valve Element  30  from Closing Position to Opening Position&gt; 
       FIG.  5    schematically illustrates one example of the state of the gate valve GV when the valve element  30  moves from the closing position to the opening position. When the valve element  30  moves from the closing position to the opening position, the switching valve  50  connects the gas line  66  to the air supply port of the switching valve  50  and connects the gas line  62  to the exhaust port. With this arrangement, when gas is supplied from the gas source  70  to the gas line  66 , the gas is supplied from the gas line  66  to the pilot port  54 , and the switching valve  52  connects the gas line  62  to the gas line  68 . This connects the space in z 2  direction relative to the piston  42  in the interior space of the cylinder  41  and the space in x 2  direction relative to the piston  46  in the interior space of the cylinder  45  to the exhaust port of the switching valve  50 . 
     Gas is then supplied to the space in z 1  direction relative to the piston  42  in the interior space of the cylinder  41  and the space in x 1  direction relative to the piston  46  in the interior space of the cylinder  45  from the gas source  70  via the gas line  66  and the branch  78 . This causes the piston  42  to be pressed in z 2  direction and the piston  46  to be pressed in x 2  direction. As a result, the valve element  30  moves in z 2  direction and x 2  direction in  FIG.  5   . When the valve element  30  moves from the closing position in z 2  and x 2  directions to reach the opening position, the valve element  30  is held at the opening position as illustrated in  FIG.  2   . 
       FIG.  6    schematically illustrates the configuration of a gate valve GV according to another exemplary embodiment.  FIG.  6    illustrates one example of the state of the gate valve GV when the valve element  30  is at the opening position. The gate valve GV illustrated in  FIG.  6    has switching valves  52 - 1  and  52 - 2  instead of the switching valve  50  in the gate valves GV illustrated in  FIGS.  2  through  5   . 
     The switching valve  52 - 1  changes the connection as to whether or not the gas line  62  is connected to the gas line  68 . The switching valve  52 - 2  changes the connection as to whether or not the gas line  64  is connected to the gas line  68 . The switching valve  52 - 1  has a pilot port  54 - 1 . The switching valve  52 - 2  has a pilot port  54 - 2 . The pilot ports  54 - 1  and  54 - 2  are both connected to the gas line  66 . 
     The switching valve  52 - 1  is a normally closed valve. The switching valve  52 - 2  is a normally open valve. That is, as illustrated in  FIG.  6   , when gas is supplied from the gas source  70  through the gas line  66  to the pilot ports  54 - 1  and  54 - 2 , the switching valve  52 - 1  connects the gas line  62  to the gas line  68 , and the switching valve  52 - 2  does not connect the gas line  64  to the gas line  68 . When gas is not supplied from the gas source  70  through the gas line  66  to the pilot ports  54 - 1  and  54 - 2 , the switching valve  52 - 1  does not connect the gas line  62  to the gas line  68 , and the switching valve  52 - 2  connects the gas line  64  to the gas line  68 . That is, the switching valves  52 - 1  and  52 - 2  are configured to connect one of the gas lines  62  and  64  to the gas line  68 . 
     With this configuration, the gate valve GV described in  FIG.  6    moves the valve element  30  from the opening position to the closing position and can hold the valve element  30  at the closing position, and moves the valve element  30  from the closing position to the opening position and can hold the valve element  30  at the opening position in a similar manner to the gate valve GV described in  FIGS.  2  through  5   . 
     According to the embodiments described above, the gate valve GV can hold the valve element  30  at the closing position using gas (e.g., the gas supplied from the gas source  72 ) that can be controlled independently of the gas used for the operation of the substrate processing module PM and/or the operation of the transfer module TM. This can provide a gate valve that reduces a leakage between the substrate processing module PM and the transfer module TM, even during maintenance of the substrate processing module PM and/or the transfer module TM. 
     One exemplary embodiment of the present disclosure can provide a gate valve and a driving method that can reduce a gas leakage. 
     The above embodiments are just for illustration of the present disclosure, and are not intended to limit the present disclosure. Various modifications may be made to the above embodiments without departing from the scope and spirit of the present disclosure. For instance, some elements in one embodiment can be added in other embodiments. Some elements in one embodiment can be replaced with corresponding elements in other embodiments.