Patent Publication Number: US-2022230898-A1

Title: Substrate processing apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to Japanese Patent Application Nos. 2021-004768 filed on Jan. 15, 2021 and 2021-163580 filed on Oct. 4, 2021, respectively, the entire contents of which are incorporated herein by reference and priority is claimed to each. 
     TECHNICAL FIELD 
     The present disclosure relates to a substrate processing apparatus. 
     BACKGROUND 
     U.S. Patent Publication No. 2020/0083071 A1 discloses a substrate processing apparatus for processing a substrate. The substrate processing apparatus includes an atmosphere part for processing a substrate in an atmospheric pressure and a depressurization part for processing a substrate in a depressurized atmosphere. The atmosphere part and the depressurization part are integrally connected via two load-lock modules whose inner atmospheres can be switched between an atmospheric pressure and a depressurized atmosphere. 
     SUMMARY 
     The technique of the present disclosure provides a substrate processing apparatus capable of attaching various modules such as a ring stocker and multiple types of processing modules having different internal dimensions, transfer distances, and the like without changing a design of a vacuum transfer module, and accurately transferring a transfer target object in the vacuum transfer module of the substrate processing apparatus. 
     In accordance with an aspect of the present disclosure, there is provided a substrate processing apparatus comprising: a vacuum transfer module having a vacuum transfer space and an opening; a wall unit attached to the opening and including a first gate valve and a second gate valve, a width of the second gate valve being greater than a width of the first gate valve; a substrate processing module attached to the wall unit and having a substrate processing space communicating with the vacuum transfer space via the first gate valve; a ring stocker attached to the wall unit and having a storage space for storing at least one annular member used in a plasma processing module, the storage space communicating with the vacuum transfer space via the second gate valve; and a transfer mechanism disposed in the vacuum transfer space and configured to transfer a substrate between the vacuum transfer space and the substrate processing space through the first gate valve and also configured to transfer at least one annular member between the vacuum transfer space and the storage space via the second gate valve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The objects and features of the present disclosure will become apparent from the following description of embodiments, given in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a plan view showing a schematic configuration of a wafer processing apparatus according to an embodiment; 
         FIG. 2  is a perspective view schematically showing a schematic configuration of a module according to an embodiment; 
         FIG. 3  is a vertical cross-sectional view showing the schematic configuration of the module according to the embodiment; 
         FIG. 4  is a schematic horizontal cross-sectional view showing configurations of an end part, a post-processing module, and a ring stocker; 
         FIG. 5  is a schematic perspective view showing a configuration of an end part according to another embodiment; 
         FIG. 6  is a schematic plan view showing the configuration of the end part according to another embodiment; 
         FIG. 7  is a detailed view of an opening plate for the substrate processing module; 
         FIG. 8  is a detailed view of an opening plate for the ring stocker; and 
         FIG. 9  schematically shows a state in which a substrate processing module and a ring stocker are attached. 
     
    
    
     DETAILED DESCRIPTION 
     In a semiconductor device manufacturing process, various steps for performing predetermined processing on a semiconductor wafer (hereinafter, simply referred to as “wafer”) in a state where a processing module containing the wafer is set to a depressurized state. These steps are executed in a substrate processing apparatus (hereinafter, also referred to as “wafer processing apparatus”) including a plurality of processing modules. 
     The wafer processing apparatus includes, e.g., an atmospheric part including an atmospheric module for performing predetermined processing on a wafer in an atmospheric pressure, and a depressurization part including a depressurization module for performing predetermined processing on a wafer in a depressurized atmosphere. The atmospheric part and the depressurization part are integrally connected through a load-lock module whose inner atmosphere can be switched between an atmospheric pressure and a depressurized atmosphere. 
     In designing a wafer processing apparatus, it is known that a plurality of processing modules or a component storage module (so-called stocker) is attached to a vacuum transfer module constituting one transfer system in a depressurization part as disclosed in U.S. Patent Publication No. 2020/0083071 A1. The modules to be attached may include, in addition to a general main process module, modules of various dimensions or configurations such as a post-processing module for post-processing on a substrate and a ring stocker for storing an edge ring such as a focus ring FR or a cover ring CR. 
     Further, in the vacuum transfer module constituting one transfer system, it may be considered to attach/detach modules and change types or configurations of modules to be attached depending on the content of the processing. 
     As multiple types of modules have different specifications or dimensions depending on the functions thereof, when they are attached to one transfer system, internal dimensions of the modules or required transfer distances may be different in the case of using a transfer mechanism of one transfer system. For example, a transfer target in the post-processing module is a substrate (wafer), whereas a transfer target in the ring stocker is an edge ring having a diameter greater than that of the substrate. Thus, both modules have different internal space dimensions. Accordingly, the transfer distances of the transfer target objects are different in different modules having different dimensions. Hence, in the case of attaching multiple modules to one transfer system, it is required to accurately transfer the transfer target objects into the respective modules. 
     In view of the above, the technique of the present disclosure provides a substrate processing apparatus in which various types of processing modules or a stocker can be attached without changing a design of a vacuum transfer module constituting one transfer system and a transfer target object can be accurately transferred by the transfer system. Hereinafter, a wafer processing apparatus as a substrate processing apparatus according to the embodiment will be described in detail with reference to the accompanying drawings. Like reference numerals will be given to like parts having substantially the same functions throughout this specification and the drawings, and redundant description thereof will be omitted. 
     &lt;Configuration of Wafer Processing Apparatus&gt; 
     First, the wafer processing apparatus according to the embodiment will be described.  FIG. 1  is a plan view showing a schematic configuration of a wafer processing apparatus  1  according to the embodiment. In the present embodiment, a case where the wafer processing apparatus  1  includes a plasma processing module for performing plasma processing such as etching, film formation, diffusion, or the like on a wafer W as a substrate will be described. Further, a case of providing a post-processing module for performing, e.g., ashing as post-processing on a substrate that has been processed in the plasma processing module, or a ring stocker for storing an annular (ring) member (edge ring) disposed to surround the periphery of the wafer W will be described. However, the module configuration of the wafer processing apparatus  1  of the present disclosure is not limited thereto, and may be arbitrarily selected depending on purposes of wafer processing. Further, various units or modules having different device configurations may be provided instead of the post-processing module or the ring stocker. 
     As shown in  FIG. 1 , the wafer processing apparatus  1  has a configuration in which an atmospheric part  10  and a depressurization part  11  are integrally connected through a load-lock module  20 . The atmospheric part  10  includes an atmospheric module for performing desired processing on the wafer W in an atmospheric pressure. The depressurization part  11  includes a decompression module for performing desired processing on the wafer W in a depressurized atmosphere. 
     The load-lock module  20  includes a plurality of (e.g., three in the present embodiment) wafer transfer chambers  21   a ,  21   b , and  21   c  arranged along a width direction (X-axis direction) of a loader module  30  to be described later and a tubular fitting module  60  to be described later. 
     The wafer transfer chambers  21   a ,  21   b , and  21   c  (hereinafter, they may be simply referred to as “wafer transfer chambers  21 ”) as substrate transfer chambers allow the inner space of the loader module  30  to be described later in the atmospheric part  10  and the inner space of the transfer module  50  to be described later in the depressurization part  11  to communicate with each other through wafer transfer ports  22  and  23 . The wafer transfer ports  22  and  23  can be opened and closed by gate valves  24  and  25 , respectively. 
     The wafer transfer chambers  21  are configured to temporarily hold the wafer W. Further, the inner atmospheres of the wafer transfer chambers  21  can be switched between an atmospheric pressure and a depressurized atmosphere (vacuum state). In other words, the load-lock module  20  is configured to appropriately transfer the wafer W between the atmospheric part  10  in the atmospheric pressure and the depressurized part  11  in the depressurized atmosphere. 
     The atmospheric part  10  includes the loader module  30  having a wafer transfer mechanism  40  to be described later, and a load port  32  on which a FOUP  31  capable of storing a plurality of wafers W is placed. An orientation module (not shown) for adjusting a horizontal direction of the wafer W, a storage module (not shown) for storing a plurality of wafers W, and the like may be disposed adjacent to the loader module  30 . 
     The loader module  30  has a rectangular housing maintained in an atmospheric pressure. A plurality of, e.g., five load ports  32  are arranged side by side on one longitudinal side of the loader module  30 , in a negative direction of the Y-axis from the loader module  30 . The wafer transfer chambers  21   a ,  21   b , and  21   c  of the load-lock module  20  are arranged side by side on the other longitudinal side of the loader module  30 , in a positive direction of the Y-axis from the loader module  30 . 
     The wafer transfer mechanism  40  for transferring the wafer W is disposed in the loader module  30 . The wafer transfer mechanism  40  includes a transfer arm  41  for holding and moving the wafer W, a rotatable table  42  for rotatably supporting the transfer arm  41 , and a rotatable table base  43  on which the rotatable table  42  is placed. Further, a guide rail  44  extending in a longitudinal direction (X-axis direction) of the loader module  30  is disposed in the loader module  30 . The rotatable table base  43  is disposed on the guide rail  44 , and the wafer transfer mechanism  40  is configured to be movable along the guide rail  44 . 
     The depressurization part  11  includes the transfer module  50  for transferring the wafer W therein, the tubular fitting module  60  that connects the load-lock module  20  and the transfer module  50 , and processing modules (hereinafter, also referred to as “plasma processing modules”)  70  for performing desired processing on the wafer W transferred from the transfer module  50 . The inner atmospheres of the transfer module  50 , the tubular fitting module  60 , and the plasma processing modules  70  can be maintained in a depressurized atmosphere. In the present embodiment, a plurality of, e.g., six plasma processing modules  70  are connected to one transfer module  50 . The number and the arrangement of the plasma processing modules  70  are not limited to those described in the present embodiment, and may be set in any appropriate manners. 
     In the depressurization part  11 , a post-processing module  100  for performing post-processing (substrate processing) on the wafer W, which is processed in the plasma processing module  70  and transferred from the transfer module  50 , and a ring stocker  105  for storing an edge ring are attached to the wall surface of the terminal end (end on the positive side of the Y-axis) of the transfer module  50 . The post-processing module  100  and the ring stocker  105  are detachable, and the arrangement thereof is not limited to that described in the present embodiment and may be set in any appropriate manners. 
     The transfer module  50  as a vacuum transfer module is connected to the load-lock module  20  through the above-described fitting module  60 . The transfer module  50  transfers the wafer W from the load-lock chamber  21   a  of the load-lock module  20  to one plasma processing module  70 . The wafer W is subjected to desired processing, and then subjected to post-processing in the post-processing module  100 , if necessary. Then, the wafer W is transferred to the atmospheric part  10  through the wafer transfer chamber  21   c  of the load-lock module  20 . In one embodiment, the transfer module  50  has a vacuum transfer space and an opening. The opening communicates with the vacuum transfer space. 
     A wafer transfer mechanism  80  as a transfer mechanism for transferring the wafer W is disposed in the transfer module  50 . In other words, the wafer transfer mechanism  80  is disposed in the vacuum transfer space. The wafer transfer mechanism  80  includes a transfer arm  81  for holding and moving the wafer W, a rotatable table  82  for rotatably supporting the transfer arm  81 , and a rotatable table base  83  on which the rotatable table  82  is placed. The rotatable table base  83  is fixed to a central portion of the transfer module  50 . In one embodiment, the wafer transfer mechanism  80  is configured to transfer the substrate between the vacuum transfer space of the transfer module  50  and the substrate processing space of the post-processing module  100  to be described later through a first gate valve  55   a . Further, the wafer transfer mechanism  80  is configured to transfer at least one annular member (edge ring) between the vacuum transfer space of the transfer module  50  and the storage space of the ring stocker  105  through a second gate valve  56   a . In one embodiment, the wafer transfer mechanism  80  is configured to transfer a plurality of annular members (edge rings) together between the vacuum transfer space and the storage space through the second gate valve  56   a . The plurality of annular members may include a first edge ring and a second edge ring to be described later. 
     The fitting module  60  connects the load-lock module  20  and the transfer module  50  as described above. 
     The plasma processing modules  70  perform plasma processing such as etching, film formation, diffusion, or the like on the wafer W. Any module for performing processing can be selected as the processing modules  70  depending on purposes of wafer processing. Further, the plasma processing modules  70  communicate with the transfer module  50  through wafer transfer ports  51  formed on sidewalls of the transfer module  50 , and the wafer transfer ports  51  can be opened and closed by gate valves  71 . 
     The post-processing module  100  performs post-processing such as ashing or the like on the wafer W processed in the plasma processing module  70 . In one embodiment, the post-processing module  100  is an ashing module. The post-processing module  100  is used, if necessary. When the post-processing module  100  is unnecessary, the wafer W processed in the plasma processing module  70  is transferred to the atmosphere part  10 . In one embodiment, the post-processing module (substrate processing module)  100  is attached to a wall unit  110  to be described later and has a processing space (substrate processing space). The processing space communicates with the vacuum transfer space of the transfer module  50  through the first gate valve  55   a  to be described later. 
     The ring stocker  105  stores a general edge ring used for improving the uniformity of processing during plasma processing performed on the wafer W in a semiconductor manufacturing apparatus. The edge ring is taken out from the ring stocker  105  and appropriately used when it is required such as when the plasma processing is performed in the plasma processing module  70 . In one embodiment, the ring stocker  105  is attached to the wall unit  110  to be described later, and has a storage space for storing at least one edge ring (annular member) used in the plasma processing module  70 . At least one edge ring is disposed to surround the substrate in the plasma processing module  70 . Alternatively, a plurality of edge rings may be used together in the plasma processing module  70 . In one embodiment, the plurality of edge rings includes a first edge ring and a second edge ring, and an outer diameter of the second edge ring is greater than an outer diameter of the first edge ring. In one embodiment, the first edge ring is made of an Si material or an SiC material and the second edge ring is made of quartz. The first edge ring and the second edge ring may be made of the same material. For example, the first edge ring and the second edge ring may be made of quartz. The storage space communicates with the vacuum transfer space of the transfer module  50  through the second gate valve  56   a  to be described later. 
     As shown in  FIG. 1 , the wafer processing apparatus  1  configured as described above includes a controller  90 . The controller  90  is, e.g., a computer having a CPU, a memory, or the like, and includes a program storage (not shown). The program storage stores a program for controlling the transfer or the processing of the wafer W in the wafer processing apparatus  1 . The program may be recorded in a computer-readable storage medium H and may be retrieved from the storage medium H and installed on the controller  90 . 
     &lt;Configuration of Modules&gt; 
     The wafer processing apparatus  1  according to the embodiment is configured as described above. Next, a detailed configuration of modules will be described.  FIGS. 2 and 3  are respectively a perspective view and a vertical cross-sectional view showing schematic configurations of the load-lock module  20 , the transfer module  50 , the fitting module  60 , the post-processing module  100 , and the ring stocker  105 . 
     As shown in  FIGS. 2 and 3 , the load-lock module  20 , the fitting module  60 , the transfer module  50 , and the post-processing module  100  (or the ring stocker  105 ) are connected side by side in that order from the negative side of the Y-axis. 
     As shown in  FIG. 2 , the load-lock module  20  has the three wafer transfer chambers  21   a ,  21   b , and  21   c  arranged side by side along the width direction (X-axis direction) of the tubular fitting module  60 . A wafer transfer port  22  for transferring a wafer W to and from the loader module  30  and a wafer transfer port  23  as a substrate transfer port for transferring a wafer W to and from the transfer module  50  are formed in each of the three wafer transfer chambers  21 . In other words, three wafer transfer ports  22  and three wafer ports  23  are formed on the sidewall of the load-lock module  20  on the negative side of the Y-axis and the sidewall of the load-lock module on the positive side of the Y-axis, respectively. 
     As described above, the wafer transfer chambers  21  of the load-lock module  20  are connected to the loader module  30  and the transfer module  50  through the gate valves  24  and the gate valves  25 , respectively. The gate valves  24  and  25  ensure airtightness between the wafer transfer chambers  21  and the loader module  30  and between the wafer transfer chambers  21  and the transfer module  50  and communication therebetween. 
     As shown in  FIG. 3 , the wafer transfer chamber  21  is provided with a stocker  26  for temporarily holding the wafer W transferred between the loader module  30  and the transfer module  50 . 
     Further, as shown in  FIG. 3 , an air supply port  27  for supplying a gas into the wafer transfer chamber  21  and a venting port  28  for venting a gas are connected to the load-lock module  20 . The load-lock module  20  is configured such that the inner atmospheres of the wafer transfer chambers  21  can be switched between an atmospheric pressure and a depressurized atmosphere by using the air supply port  27  and the venting port  28 . 
     An opening  52  through which the wafer W is transferred to and from the fitting module  60  is formed at one end of the transfer module  50  on the negative side of the Y-axis to which the fitting module  60  is connected. Further, a wafer transfer port  57   a  is formed on a terminal wall surface  57  as the other end of the transfer module  50  on the positive side of the Y-axis. An end part (wall unit)  110  for transferring the wafer W between the post-processing module  100  and the ring stocker  105  is attached to the terminal wall surface  57 . A placement table  101  or  106  for placing the wafer W or the edge ring thereon is disposed in each of the post-processing module  100  and the ring stocker  105 . 
     The end part  110  includes a main body  112  where wafer transfer port  111  ( 111   a  and  111   b ) is formed, and the first gate valve  55   a  and the second gate valve  56   a  to be described later. In one embodiment, the wall unit  110  is attached to the opening of the transfer module  50 . In other words, the wall unit  110  defines a part of the vacuum transfer space. In one embodiment, the wall unit  110  has a first space and a second space. The first space of the wall unit  110  is disposed between the vacuum transfer space of the transfer module  50  and the substrate processing space of the post-processing module  100 . The second space of the wall unit  110  is disposed between the vacuum transfer space of the transfer module  50  and the storage space of the ring stocker  105 . The first gate valve  55   a  is disposed in the first space, and the second gate valve  56   a  is disposed in the second space. In one embodiment, the first gate valve  55   a  is disposed on the surface of the wall unit  110  close to the post-processing module  100 , and the second gate valve  56   a  is disposed on the surface of the wall unit  110  close to the ring stocker  105 . In one embodiment, the inner length of the second space is greater than the inner length of the first space. In this case, the second gate valve  56   a  is distant from the transfer module  50  compared to the first gate valve  55   a . Detailed configurations of the post-processing module  100  and the ring stocker  105  will be described later with reference to  FIG. 4 . 
     As illustrated, no plate or gate valve is disposed between the transfer module  50  and the tubular fitting module  60 . In other words, the inner space of the transfer module and the inner space of the tubular fitting module  60  communicate with each other, thereby defining an integrated transfer space S where the wafer W is transferred by the wafer transfer mechanism  80 . 
     As described above, a plurality of (six to correspond to the number of plasma processing modules  70  in the present embodiment) wafer transfer ports  51  communicating with the plasma processing modules  70  are formed on the longitudinal sides of the transfer module  50  on the negative side and the positive side of the X-axis. The wafer transfer ports  51  can be opened and closed by the gate valves  71  (see  FIG. 1 ). 
     Further, a gas supply  54  for supplying an inert gas (e.g., N 2  gas) to the transfer space S is connected to a ceiling surface of the transfer module  50  that is located above the wafer transfer ports  51 . The gas supply  54  supplies an inert gas to the transfer space S to shut off the wafer transfer ports  51 , i.e., to form an air curtain. Therefore, scattering of particles or the like from the plasma processing modules  70  into the transfer module  50  at the time of opening the gate valves  71  is suppressed. 
     Further, the gas supply  54  supplies an inert gas into the transfer space S to eliminate stagnation of air flow in the transfer space S and appropriately exhaust the transfer space S using an exhaust mechanism  64  (to be described later) connected to the tubular fitting module  60 . 
     &lt;Configurations of Post-Processing Module and Ring Stocker&gt; 
     Next, the detailed configurations of the post-processing module  100  and the ring stocker  105  will be described.  FIG. 4  is a schematic horizontal cross-sectional view showing the configurations of the end part (wall unit)  110 , the post-processing module  100 , and the ring stocker  105  disposed at the terminal wall surface  57  of the transfer module  50  in the wafer processing apparatus  1 , and shows an enlarged view of the vicinity of the post-processing module  100  and the ring stocker  105 . In  FIG. 4 , a state in which the wafer transfer mechanism  80  (transfer arm  81 ) is extended into each module is indicated by dashed lines. 
     As shown in  FIG. 4 , the end part  110  including the first gate valve  55   a  and the second gate valve  56   a  is attached to the terminal wall surface  57  of the transfer module  50 . The end part  110  includes the main body  112  having the wafer transfer port  111  ( 111   a  and  111   b ) that can be opened and closed by the first gate valve  55   a  and the second gate valve  56   a . The end part  110  is configured such that the main body  112  can be attached to the terminal wall surface  57  of the transfer module  50 . The attachment method is not particularly limited, but the main body  112  may be attached to the terminal wall surface  57  using screws, for example. The post-processing module  100  is attached to the end wall surface  57  through the first gate valve  55   a  of the end part  110 , and the ring stocker  105  is attached thereto through the second gate valve  56   a  of the end part  110 . 
     The main body  112  of the end part  110  is formed by connecting a first main body  112   a  and a second main body  112   b . The first main body  112   a  is a hollow housing that connects the terminal wall surface  57  and the post-processing module  100 . The side surface of the first main body  112  facing the terminal wall surface  57  is opened, and the wafer transfer port  111   a  is formed on the side surface of the first main body  112  facing the post-processing module  100 . The first gate valve  55   a  is disposed in the first main body  112   a . The second main body  112   b  is a hollow housing that connects the terminal wall surface  57  and the ring stocker  105 . The side surface of the second main body  112   b  facing the terminal wall surface  57  is opened, and the wafer transfer port  111   b  is formed on the side surface of the second main body  112   b  facing the ring stocker  105 . The second gate valve  55   b  is disposed in the first main body  112   a . The configuration of the main body  112  is arbitrary. For example, in the configuration of the present embodiment, the first gate valve  55   a  and the second gate valve  56   a  have different configurations, so that the thickness (thickness in the Y-axis direction) in the width direction (X-axis direction) varies depending on portions. 
     The configuration of the end part  110  is not limited to the illustrated one. For example, the first gate valve  55   a  and the second gate valve  56   a  may have different dimensions or structures. In other words, the first gate valve  55   a  may be a so-called bonnet type gate valve, and the second gate valve  56   a  may be a so-called insert type gate valve. The bonnet type first gate valve is attached to a convex portion of the first main body  112   a . The insert type gate valve is attached to a concave portion of the second main body  112   b.    
     In the configuration of the present embodiment, as shown in  FIG. 4 , the end part  110  has a configuration in which a thickness L 1  in the Y-axis direction of the portion corresponding to the first gate valve  55   a  and a thickness L 2  in the Y-axis direction of the portion corresponding to the second gate valve  56   a  are different and have a relationship of L 1 &lt;L 2 . In other words, the distance L 1  between the post-processing module  100  and the terminal wall surface  57  of the transfer module  50  is smaller than the distance L 2  between the ring stocker  105  and the terminal wall surface  57  of the transfer module  50 . 
     Various modules such as the post-processing module  100  and the ring stocker  105  have different chamber thicknesses, internal space dimensions, and the like depending on characteristics thereof, so that the distances from the module entrances to the transfer center are different depending on the modules. In the configuration of the present embodiment, as shown in  FIG. 4 , a distance M 1  from the module entrance to the transfer center in the post-processing module  100  and a distance M 2  from the module entrance to the transfer center in the ring stocker  105  have a relationship of M 1 &gt;M 2 . This is because the post-processing module  100  that may perform plasma processing has a thick module wall and the size of the entire housing of the module is larger than that of the ring stocker  105 . 
     Further, as shown in  FIG. 4 , a width (dimension in the X-axis direction) D 1  of the first gate valve  55   a  and a width (dimension in the X-axis direction) D 2  of the second gate valve  56   a  have a relationship of D 1 &lt;D 2 . This is because the transfer target of the post-processing module  100  is the wafer W, whereas the transfer target of the ring stocker  105  is an edge ring having a diameter greater than that of the wafer W. 
     In designing the wafer processing apparatus  1  in the semiconductor device manufacturing process, the design or dimensions of various modules such as the post-processing module  100  and the ring stocker  105  are predetermined depending on the processing content and the like. In other words, the distance M 1  from the module entrance to the transfer center in the post-processing module  100  and the distance M 2  from the module entrance to the transfer center in the ring stocker  105  are predetermined. 
     On the other hand, the end part  110  of the present embodiment is detachably attached to the terminal wall surface  57  of the transfer module  50 . In other words, the design thereof is arbitrary, and multiple types of end parts  110  can be manufactured and prepared. It is also possible to arbitrarily design the widths D 1  and D 2  of the first gate valve  55   a  and the second gate valve  56   a  accommodated in the end part  110 . For example, as in the configuration of the present embodiment, it is possible to use the end part  110  designed to accommodate the first gate valve  55   a  having the width D 1  suitable for the design of the post-processing module  100  and the second gate valve  56   a  having the width D 2  suitable for the design of the ring stocker  105 . 
     In the wafer processing apparatus  1  of the present embodiment, as described above, the end part  110  is detachably attached to the terminal wall surface  57  of the transfer module  50 , and various modules such as the post-processing module  100  and ring stocker  105  are attached through the end part  110 . Accordingly, it is possible to attach various modules such as the post-processing module  100  and the ring stocker  105  through the end part  110  without changing the design of the transfer module  50  as the vacuum transfer module. 
     By properly designing the end part  110 , the transfer target object (the wafer W, the edge ring, or the like) can be accurately transferred to the post-processing module  100  and the ring stocker  105 . Specifically, the transfer distance in each module can be desirably adjusted by manufacturing the end part  110  in which the thickness L 1  in the Y-axis direction of the first gate valve  55   a  and the thickness L 2  in the Y-axis direction of the second gate valve  56   a  are set to desired values. Specifically, the transfer distance in the post-processing module  100  according to the present embodiment is L 1 +M 1 , and the transfer distance in the ring stocker  105  is L 2 +M 2 . By changing the values of L 1  and L 2  depending on the design of the end part  110 , the transfer distance in each module can be designed to a desired distance. 
     The embodiments of the present disclosure are illustrative in all respects and are not restrictive. The above-described embodiments may be omitted, replaced, or changed in various forms without departing from the scope of the appended claims and the gist thereof. 
     In the above-described embodiment, the case where the end part  110  includes the first gate valve  55   a  that is a so-called bonnet type gate valve, and the second gate valve  56   a  that is a so-called insert type gate valve has been illustrated and described, but the present disclosure is not limited to thereto. For example, when two post-processing modules are attached to the terminal wall surface  57  of the transfer module  50 , an end part accommodating two so-called bonnet type gate valves may be manufactured. Further, for example, when two ring stockers are attached to the terminal wall surface  57  of the transfer module  50 , an end part accommodating two so-called insert type gate valves may be manufactured. As described above, since the end part is detachably attached to the transfer module  50 , the end parts may be distinguished depending on types of module to be attached. Therefore, the wafer processing apparatus  1  includes a flexible system attached to the opening of the transfer module  50 . The flexible system selectively includes any one of a first replaceable unit, a second replaceable unit and a third replaceable unit. The first replaceable unit includes a first wall unit (not shown) and two post-processing modules  100 . The first wall unit is attached to the opening of the transfer module  50  and includes two first gate valves  55   a . The two post-processing modules  100  are attached to the first wall unit. Each of the post-processing modules  100  has a substrate processing space communicating with the vacuum transfer space of the transfer module  50  through the first gate valve  55   a . The second replaceable unit includes a second wall unit (not shown) and two ring stockers  105 . The second wall unit is attached to the opening of the transfer module  50  and includes two second gate valves  56   a . The two ring stockers  105  and  105  are attached to the second wall unit. Each of the ring stockers  105  has a storage space for storing one or more edge rings (annular members) used in the plasma processing module  70 . The storage space communicates with the vacuum transfer space of the transfer module  50  through the second gate valve  56   a . The third replaceable unit includes a third wall unit  110 , one post-processing module  100 , and one ring stocker  105 . 
     End parts of various designs and configurations may be considered. For example, when the module is not attached to the end wall  57  of the transfer module  50 , a so-called end plate that covers and blocks the end wall  57  with a plate-shaped member may be attached. In other words, a unit flexible system may selectively include any one of a first replaceable unit, a second replaceable unit, a third replaceable unit, and a fourth replaceable unit. The fourth replaceable unit includes a fourth wall unit (end plate). In addition, the wafer processing apparatus  1  may have a configuration in which an additional vacuum transfer module is connected to one vacuum transfer module. In that case, instead of the end part according to the above-described embodiment, a tubular path module that connects the vacuum transfer modules and transfers the substrate between the vacuum transfer modules may be attached. 
     Further, instead of the configuration of the end part  110  according to the above-described embodiment, the end part  110  may include a common end plate and opening plates corresponding to the replaceable units (e.g., the post-processing module  100  and the ring stocker  105 ).  FIGS. 5 and 6  schematically explain a configuration of an end part  110  according to another embodiment.  FIG. 5  is a schematic perspective view, and  FIG. 6  is a schematic plan view. In describing the present embodiment, like reference numerals will be given to like parts having the same functions as those of the above-described embodiment, and redundant description thereof may be omitted. 
     As shown in  FIGS. 5 and 6 , the end part  110  includes a common end plate  120  accommodating two gate valves, and an opening plate for the substrate processing module for the substrate processing module  124  and an opening plate for the ring stocker  126  that are detachably disposed to correspond to gate valves  130 . In the present embodiment, the configuration of the two gate valves  130  disposed at the end part  110  is arbitrary, and the gate valves  130  may be any one of the above-described so-called bonnet type gate valve and insert type gate valve, for example. 
     In other words, in a state where the common end plate  120  is attached to the terminal wall surface  57  of the transfer module  50 , the opening plate for the substrate processing module  124  and the opening plate for the ring stocker  126  may be detachably provided in any configuration. Any attachment/detachment device may be used, and they may be fixed by screws, for example. For example, as shown in  FIG. 6 , the opening plate for the substrate processing module  124  and the post-processing module  100  may be attached to one of the gate valves  130  in that order from the apparatus main body side. Further, the opening plate for the ring stocker  126  and the ring stocker  105  may be attached to the other gate valve  130  in that order from the apparatus main body side. 
       FIG. 7  is a detailed view of the opening plate for the substrate processing module  124 .  FIG. 8  is a detailed view of the opening plate for the ring stocker  126 .  FIG. 7  shows a state in which the opening plate for the substrate processing module  124  is attached to the post-processing module  100 .  FIG. 8  shows a state in which the opening plate for the ring stocker  126  is attached to the ring stocker  105 . As can be seen from the comparison of  FIGS. 7 and 8 , the thickness of the opening plate for the substrate processing module  124  and the thickness of the opening plate for the ring stocker  126  are considerably different. The opening plate for the ring stocker  126  is thicker than the opening plate for the substrate processing module  124 . Accordingly, as described in the above-described embodiment, the end part  110  may have the configuration in which the thickness L 1  in the Y-axis direction at one gate valve  130  and the thickness L 2  in the Y-axis direction at the other gate valve  130  may be different (L 1 &lt;L 2 ) (see  FIG. 6 ). 
     In the present embodiment, the opening plate for the substrate processing module  124  and the opening plate for the ring stocker  126  are attached and detached, if necessary. Accordingly, the transfer distance L 1 +M 1  in the post-processing module  100  and the transfer distance L 2 +M 2  in the ring stocker  105  can be easily adjusted using the opening plate corresponding to a desired module to be attached. In particular, since both transfer distances can be easily adjusted without replacing the common end plate  120 . 
       FIG. 9  schematically shows a state in which the post-processing module  100  and the ring stocker  105  are attached to the gate valves  130  of the end part  110  according to the present embodiment. As shown in  FIG. 9 , the dimensions of the modules attached to the terminal wall surface  57  of the transfer module  50  through the end part  110  may be considerably different depending on types thereof. By employing the configuration in which the end part  110  includes the common end plate  120  and the opening plates  124  and  126 , various modules can be easily attached and detached even when the dimensions of the modules to be attached are considerably different as shown in  FIG. 9 . 
     In the above-described embodiment, the wafer transfer mechanism  80  basically transfers the wafer W. However, the edge ring ER may be used when plasma processing is performed on the wafer W in the plasma processing module  70  as in the wafer processing apparatus  1  according to the present embodiment. In that case, the edge ring ER can be transferred by a vacuum transfer part. For example, the ring stocker  105  according to the above-described embodiment stores a general edge ring used for performing the plasma processing in the plasma processing module  70 . In such a configuration, the wafer transfer mechanism  80  is preferably configured to transfer the edge ring as well as the wafer W. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the disclosures. Indeed, the embodiments described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the disclosures. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the disclosures.