Patent Publication Number: US-2015078863-A1

Title: Conveyor

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a Continuation Application of PCT International Application No. PCT/JP2013/063615, filed on May 9, 2013, which claimed the benefit of Japanese Patent Application No. 2012-116851, filed on May 22, 2012, the entire content of each of which is hereby incorporated by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a transfer device configured by combining a plurality of transfer units and having a transfer base movable by a linear motor mechanism. 
     BACKGROUND 
     In a substrate processing system for processing substrates, for example, semiconductor device wafers (hereinafter, simply referred to as “wafers”), wafer processing efficiency can be improved by providing a plurality of process modules, each of which is a substrate processing apparatus that processes substrates one by one. 
     The substrate processing system further includes a load lock module, which is a loading/unloading device for loading and unloading wafers to and from the substrate processing system, and a transfer module that is a transfer device connected to the load lock module. The plurality of process modules are connected to the transfer module. The transfer module has a transfer base for transferring wafers, and the transfer base is moved within the transfer module to transfer the wafers between the load lock module and the respective process modules. 
     In general, in order to efficiently arrange the plurality of process modules, the transfer module consists of a chamber elongated in one direction, and the transfer base is moved within the transfer module in the elongated direction. 
     Conventionally, a ball screw mechanism has been used as a moving mechanism of the transfer base. For example, the ball screw mechanism has a feed screw  101  disposed within a transfer module  100  along an elongated direction of the transfer module  100 , and a feed screw hole  103  provided in a transfer base  102  and screw-coupled with the feed screw  101 , as illustrated in  FIG. 10 . As the feed screw  101  is rotated about its axis, the feed screw hole  103  converts the rotational force of the feed screw  101  to the moving force of the transfer base  102 , so that the transfer base  102  is moved along the feed screw  101 . The Y, X, and Z directions in  FIG. 10  indicate the moving direction of the transfer base  102 , the direction perpendicular to the moving direction of the transfer base  102  in a wafer transfer plane, and the height direction of the transfer module  100 , respectively. 
     Wafers that have an enlarged diameter require enlargement of the process module and further the transfer module. If the transfer module is enlarged, it is necessary to make the feed screw  101  longer in order to increase a moving amount of the transfer base. 
     The feed screw  101  is formed in the shape of a round bar, and thus the feed screw  101  is easily bent. Accordingly, if the feed screw  101  is made longer, there is a problem in that it is difficult for the transfer base  102  to be accurately moved, because the feed screw  101  is bent due to the weight of the transfer base. 
     Therefore, a magnetic driving mechanism has been introduced to move a transfer base. For example, the magnetic driving mechanism has a rail  111  disposed within a transfer module  110  along the elongated direction of the transfer module  110 , an arm  112  movable along the rail  111 , and a driver (not shown) movable outside the transfer module  110  along the rail  111 , as illustrated in  FIG. 11 . In the transfer module  110 , since a magnetic head (not shown) of the arm  112  is magnetically coupled with the driver, the magnetic head and further the arm  112  are moved along with the movement of the driver. The shape of the rail  111  is not specifically limited, because the rail  111  needs only to guide the arm  112 . Even when the rail  111  is made longer, for example, the rail  111  can be suppressed from being bent and the arm  112  can be moved accurately, by increasing the height of the rail  111  to increase the second moment of area of the rail  111 . The Y and X directions in  FIG. 12  indicate the moving direction of the arm  112  and the direction perpendicular to the moving direction of the arm  112  in a wafer transfer plane, respectively. 
     However, the transfer module  110  of  FIG. 11  has a problem in that metal powder or the like is generated due to the contact between the rail  111  and the arm  112 , which contaminates a wafer. In addition, although it is necessary to flexibly control the number of wafers to be processed due to the large fluctuation in demand for semiconductor devices, the transfer module  110  of  FIG. 11  has a problem in that, since the rail  111  is formed in the shape of a single bar, it is difficult to extend the rail  111  and thus it is impossible to flexibly control the number of wafers to be processed by increasing the number of process modules. 
     In order to cope with the aforementioned problems, it has been studied, recently, to use a linear motor mechanism for moving the transfer base. 
       FIG. 12  is a plane view illustrating a schematic configuration of a conventional substrate processing system using a linear motor mechanism. In addition, for illustrative purposes,  FIG. 12  shows a state where lids of transfer units  121  to be described later are removed. The Y and X directions in  FIG. 12  indicate the moving direction of a transfer base  126  described later and the direction perpendicular to the moving direction of the transfer base  126  in a wafer transfer plane, respectively. 
     In  FIG. 12 , a substrate processing system  120  includes a transfer module  122  configured by serially connecting the transfer units  121 , each of the transfer units  121  consisting of a chamber in the shape of a housing, a plurality of process modules  123  connected to the respective transfer units  121 , and two load lock modules  124  connected to one end of the transfer module  122 . 
     In addition, the substrate processing system  120  further includes a pair of coil arrays  125  arranged within the transfer module  122  along the elongated direction of the transfer module  122 , and the rectangular parallelepiped transfer base  126  interposed between the coil arrays  125 . 
     Magnets  127  are disposed at both sides of the transfer base  126  to face the coil arrays  125 , respectively, so that the transfer base  126  is moved along the coil arrays  125  by an electromagnetic force generated when respective coils  128  of the coil arrays  125  are powered on . Since the transfer base  126  is attracted by the electromagnetic force toward the respective coil arrays  125  with the transfer base  126  interposed therebetween, the transfer base  126  is positioned in the center between both the coil arrays  125  and thus is not in contact with any one of the coil arrays  125 . 
     The transfer module  122  may be elongated by installing additional transfer units  121 . In such a case, each of the coil arrays  125  may be easily extended by arranging additional coils  128  in the additional transfer units  121 . 
     In each of the transfer units  121  of  FIG. 12 , since it is necessary to connect power supply wires  132  to the respective coils  128  from the outside, as illustrated in  FIG. 13 , through holes  129  need to be machined and bored through a wall surface of each transfer unit  121 . The inside of the transfer unit  121  is in communication with the inside of the process module  123 , and thus the inside of the transfer unit  121  is depressurized. Thus, it is necessary to block the through holes  129  with the coils  128  and also to seal gaps between the coils  128  and the inner wall surface of the transfer unit  121 . Accordingly, seal grooves  130  for inserting sealing members, such as O-rings, need to be formed in the inner wall surface of the transfer unit  121 . However, the seal grooves  130  cannot be formed for the coil  128  disposed in the vicinity of an end portion  121   a  of the transfer unit  121 , because a ceiling portion  121   b  of the transfer unit  121  interferes with a machining tool  131  so that the machining tool  131  does not reach a desirable machining position. In addition, for the same reason, screw holes  133  for coil installation cannot be formed. As a result, since the coils  128  cannot be disposed in the vicinity of the end portion  121   a  of the transfer unit  121 , the plurality of coils  128  cannot be uniformly disposed in each of the coil arrays  125 , and thus the electromagnetic force cannot be uniformly exerted on the transfer base  126 . Therefore, there is a problem in that the transfer base  126  cannot be smoothly moved. The Y and Z directions in  FIG. 13  indicate the arrangement direction the plurality of coils  128  and the height direction of the transfer units  121 , respectively. 
     SUMMARY 
     The present disclosure provides some embodiments of a transfer device capable of realizing smooth movement of a transfer base by securing a degree of freedom in coil arrangement. 
     According to one embodiment of the present disclosure, there is provided a transfer device configured by connecting a plurality of housing-shaped transfer units in series, the transfer device including: a pair of coil arrays including a plurality of coils arranged in the transfer units along an arrangement direction of the plurality of transfer units; a transfer base disposed between the pair of coil arrays and configured to move in the transfer unit along the arrangement direction to transfer a substrate; and a plurality of fitting parts installed in one to one correspondence with the coils, each of the fitting parts being interposed between a corresponding one of the coils and an inner wall surface of one of the transfer units so that each of the coils is installed on a corresponding one of the fitting parts. An inside of each of the transfer units is depressurized below atmospheric pressure. The transfer base has a plurality of magnets facing each of the pair of coil arrays. A plurality of through holes is formed in one to one correspondence with the coils in each of the transfer units, the through holes penetrating from inside of the transfer units to outside of the transfer units. Each of the fitting parts has a bar-shaped protrusion configured to be inserted into a corresponding one of the through holes. A sealing member is interposed between the protrusion and the corresponding one of the through holes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure. 
         FIG. 1  is a plane view illustrating a schematic configuration of a substrate processing system having a transfer device according to an embodiment of the present disclosure. 
         FIG. 2  is a perspective view illustrating a positional relationship between coil arrays, power supply wires and a slide box inside a transfer unit in  FIG. 1 . 
         FIG. 3  is a sectional view illustrating the positional relationship between the coil arrays, the power supply wires and the slide box inside the transfer unit in  FIG. 1 . 
         FIG. 4  is a perspective view illustrating a schematic configuration of an adaptor for coil installation. 
         FIG. 5  is a sectional view illustrating an installation state of the adaptor to the transfer unit. 
         FIG. 6  is a sectional view illustrating a state of machining a through hole in the transfer unit. 
         FIGS. 7A and 7B  are views illustrating a method for resolving misalignment in rotational directions of the respective coils in the coil array. 
         FIG. 8  is a perspective view illustrating a schematic configuration of a first modification of the adaptor of  FIG. 4 . 
         FIG. 9  is a perspective view illustrating a schematic configuration of a second modification of the adaptor of  FIG. 4 . 
         FIG. 10  is a transparent perspective view illustrating a schematic configuration of a conventional transfer module using a ball screw mechanism. 
         FIG. 11  is a plane view illustrating a schematic configuration of a conventional transfer module using a magnetic driving mechanism. 
         FIG. 12  is a plane view illustrating a schematic configuration of a conventional substrate processing system using a linear motor mechanism. 
         FIG. 13  is a sectional view illustrating a state of machining seal grooves or screw holes for coil installation in an inner wall surface of a transfer unit of  FIG. 12 . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure. However, it will be apparent to one of ordinary skill in the art that the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, systems, and components have not been described in detail so as not to unnecessarily obscure aspects of the various embodiments. 
       FIG. 1  is a plane view illustrating a schematic configuration of a substrate processing system having a transfer device according to an embodiment of the present disclosure. For illustrative purposes,  FIG. 1  illustrates a state where lids of transfer units  11  described later are removed. In  FIGS. 1 to 9 , Y, X and Z directions indicate a moving direction of a slide box  17  described later, a direction perpendicular to the moving direction of the slide box  17  in a wafer transfer plane, and a height direction of a transfer module  12  described later, respectively. 
     In  FIG. 1 , a substrate processing system  10  includes the transfer module (transfer device)  12  configured by serially connecting the transfer units  11 . Each of the transfer units  11  consists of a chamber in the shape of a housing, a plurality of process modules  13  connected to the respective transfer units  11 , and two load lock modules  14  connected to one end of the transfer module  12 . 
     For each of the transfer units  11 , two of the process modules  13  are arranged to face each other with the corresponding transfer unit  11  interposed therebetween. The inside of each process module  13  is depressurized, and a plasma process, for example, a dry etching process or a film forming process, is performed on a wafer W accommodated in the process module  13 . 
     In the transfer module  12 , the inside of the transfer units  11  communicate with each other to define a transfer space S. The transfer space S is depressurized below atmospheric pressure by an exhaust device or pressure valves (both not shown), with which the transfer module  12  is provided. Specifically, a pressure of the transfer space S is set to be almost the same as the internal pressure of each process module  13 . 
     The transfer module  12  has a pair of coil arrays  15  arranged along the arrangement direction of the transfer units  11 , two power supply wires  16  arranged in parallel with the coil arrays  15 , and the rectangular parallelepiped slide box (transfer base)  17  disposed within the transfer space S. 
     The coil arrays  15  consist of a plurality of rectangular coils  18 , which are arranged in two parallel rows on the inside bottom portion of each transfer unit  11 . Each of the coils  18  is supplied with electric power from the outside of the transfer module  12 , and switches magnetic poles according to the supplied electric power to generate an electromagnetic force. Each of the power supply wires  16  is formed in the shape of a pipe arranged on the inside bottom portion of each transfer unit  11 , and is supplied with electric power from the outside of the transfer module  12 . 
       FIG. 2  is a perspective view illustrating a positional relationship between the coil arrays, the power supply wires and the slide box inside the transfer unit in  FIG. 1 , and  FIG. 3  is a sectional view illustrating the positional relationship between the coil arrays, the power supply wires and the slide box inside the transfer unit in  FIG. 1 . For simplification of description, in  FIG. 2 , a transfer arm  21  described later and sidewalls of the transfer unit  11  are omitted, and the slide box  17  is spaced apart from the bottom portion of the transfer unit  11 . 
     In  FIGS. 2 and 3 , the slide box  17  is interposed between the pair of coil arrays  15 , and a plurality of permanent magnets  19  are arranged on both sides of the slide box  17  to face the coil arrays  15 , respectively. The coil arrays  15  and the permanent magnets  19  constitute a linear motor mechanism, and the electromagnetic force generated by the coils  18  electromagnetically drives and moves the slide box  17  along the coil arrays  15 . Since the slide box  17  is interposed between the pair of coil arrays  15 , the slide box  17  is pulled toward the respective coil arrays  15  and positioned in the center between the coil arrays  15  without being in contact with any one of the coil arrays  15 . Accordingly, it is possible to suppress generation of particles such as metal powder caused by the contact, and thus the wafer W transferred by the slide box  17  can be prevented from being contaminated by particles. The slide box  17  may be supported by a guide (not shown) or supported in a floating manner by magnet arrays (not shown) disposed on the inner sidewalls or the like of each transfer unit  11 . 
     The slide box  17  has the rotatable and extendable transfer arm  21  on the top thereof, an electric unit  22  in an inside thereof for driving the transfer arm  21  and also communicating with a control unit (not shown) of the substrate processing system  10 , and a power receiving transformer  20  on the bottom thereof. The power supply wires  16  supply electric power to the electric unit  22  in a non-contact manner through the power receiving transformer  20 , and the electric unit  22  controls the driving of the transfer arm  21  based on a control signal received from the control unit. 
     The transfer module  12  performs loading and unloading of the wafer W to and from the process modules  13  by combining the movement of the slide box  17  and the rotation and extension of the transfer arm  21 . 
     Returning to  FIG. 1 , the load lock modules  14  perform loading and unloading of the wafer W between the transfer module  12  and the outside of the substrate processing system  10 . Each of the load lock modules  14  is configured such that the inside thereof can be depressurized. When the wafer W is loaded into the transfer module  12  from the outside of the substrate processing system  10 , the load lock module  14  receives the wafer W from a container of the wafer W, for example a FOUP, the inside of the load lock module  14  is depressurized to the same pressure as that of the transfer space S, and then the load lock module  14  delivers the wafer W to the transfer arm  21  of the slide box  17 . When the wafer W is unloaded from the transfer module  12  to the outside of the substrate processing system  10 , the load lock module  14  receives the wafer W from the transfer arm  21 , the internal pressure of the load lock module  14  is increased to atmospheric pressure, and then the load lock module  14  delivers the wafer W to the FOUP. 
     In the substrate processing system  10 , the transfer module  12  may be elongated by installing an additional transfer unit  11 . Specifically, the additional transfer unit  11  is connected to an end portion of the transfer module  12  opposite to the end portion where the load lock modules  14  are connected, and the inside of the additional transfer unit  11  communicates with the transfer space S, thereby elongating the transfer module  12 . Like the other transfer units  11 , a plurality of rectangular coils  18  are arranged in two parallel rows and two power supply wires  16  are disposed on the inside bottom portion of the additional transfer unit  11 . Thus, when the additional transfer unit  11  is connected to the transfer module  12 , the plurality of coils  18  of the additional transfer unit  11  elongate the pair of coil arrays  15  of the transfer module  12 , and the power supply wires  16  of the additional transfer unit  11  elongate the respective power supply wires  16  of the transfer module  12 . 
     Therefore, in the substrate processing system  10 , the transfer module  12  can be easily elongated, and accordingly, process modules  13  connected to the transfer unit  11  can be additionally installed. On the contrary, by removing one or more of the transfer units  11  from the transfer module  12 , the transfer module  12  can be easily shortened, and accordingly, the process modules  13  can be reduced in number. That is, the number of wafers W to be processed can be easily increased and decreased in the substrate processing system  10 . 
     In transfer modules using the conventional linear motor mechanism, when the coils are arranged on the inside bottom portion of the transfer unit, it is necessary to form seal grooves for inserting sealing members in the inner wall surface of the transfer unit in order to seal gaps between the coils and the inner wall surface of the transfer unit. 
     In the transfer module  12  as the transfer device according to the present embodiment, in order not to form the seal grooves in the inner wall surfaces of the transfer units  11 , adaptors (fitting parts)  23  are interposed between the coils  18  and the inner wall surfaces of the transfer units  11 . The adaptors  23  are installed in one to one correspondence with the coils  18 , and each of the coils  18  is installed on a corresponding one of the adaptors  23 . 
       FIG. 4  is a perspective view illustrating a schematic configuration of the adaptor for coil installation, and  FIG. 5  is a sectional view illustrating an installation state of the adaptor to the transfer unit. For simplification of description, the coil  18  is spaced apart from the adaptor  23  in  FIG. 4 . 
     In  FIGS. 4 and 5 , the adaptor  23  has a base portion  23   a  in the shape of a rectangular flat plate, a wall-shaped stopper  23   b  protruding upward in the drawings from the base portion  23   a , and a bar-shaped shaft (protrusion)  23   c  protruding downward in the drawings from about the center of the base portion  23   a.    
     The upper surface of the base portion  23   a  forms a contact surface with the coil  18  when the coil  18  is installed on the adaptor  23 . A seal groove  23   d  for inserting a sealing member, for example, an O-ring (not shown), to seal the gap between the coil  18  and the contact surface is formed in the contact surface, and an electric contact  23   f  as a protrusion for supplying electric power to the coil  18  is also installed on the contact surface. The stopper  23   b  is brought into contact with a lateral surface of the coil  18  when the coil  18  is installed on the adaptor  23 , which prevents positional misalignment of the coil  18  with respect to the adaptor  23 . A lateral side of the shaft  23   c  is male-threaded, and an O-ring (sealing member)  23   e  is disposed to surround the shaft  23   c  approximately in the center of the shaft  23   c  in its length direction. Specifically, the O-ring  23   e  is disposed on the shaft  23   c  by inserting the O-ring  23   e  into an O-ring groove formed along the circumferential direction of the shaft  23   c.    
     Through holes  24  for coil installation are formed in one to one correspondence with the coils  18  in the bottom portion of the transfer unit  11 . When the coils  18  are arranged on the inside bottom portion of the transfer unit  11 , the coils  18  are first installed on the corresponding adaptor  23 , and then the shaft  23   c  of the adaptor  23  is inserted into the corresponding through hole  24  from the inside bottom portion of the transfer unit  11 . Then, a nut  25  is screw-coupled to a portion of the shaft  23   c  protruding from the through hole  24  to the outside of the transfer unit  11 , thereby tightly fixing the adaptor  23  to the transfer unit  11 . Here, the O-ring  23   e  of the shaft  23   c  is interposed between the inner surface of the through hole  24  and the lateral surface of the shaft  23   c  and also brought into press contact with the inner surface of the through hole  24 , thereby blocking communication between the inside and outside of the transfer unit  11  through the through hole  24 . That is, the O-ring  23   e  seals the inside of the transfer unit  11  from the outside thereof. Here, the O-ring  23   e  is inserted into the O-ring groove formed on the shaft  23   c.  An O-ring groove may be also formed on the inner surface of the through hole  24 , and when the shaft  23   c  is inserted into the through hole  24 , the O-ring  23   e  of the shaft  23   c  may be insertion-fitted into the O-ring groove formed on the inner surface of the through hole  24 . Alternatively, without forming the O-ring groove on the shaft  23   c,  the O-ring groove may be formed only on the inner surface of through hole  24  and the O-ring  23   e  may be insertion-fitted only into the O-ring groove formed on the inner surface of the through hole  24   
     Since the O-ring  23   e  surrounds the shaft  23   c,  a reaction force received by the O-ring  23   e  from the inner surface of the through hole  24  acts on the shaft  23   c  in all directions. Thus, the shaft  23   c  is set to be positioned at the center of the through hole  24  such that the through hole  24  and the shaft  23   c  are concentric with each other. That is, the position of the adaptor  23  is determined only by inserting the shaft  23   c  into the through hole  24  and screw-coupling the shaft  23   c  with the nut  25 . 
     According to the transfer module  12  as the transfer device of the present embodiment, since the O-ring  23   e  is interposed between the inner surface of each through hole  24  of the transfer unit  11  and the lateral surface of each shaft  23   c,  it is not necessary to seal the gap between the inner wall surface of the transfer unit  11  and the base portion  23   a  of each adaptor  23  and to form the seal groove on the inner wall surface of the transfer unit  11 . In addition, since the adaptor  23  can be installed on the transfer unit  11  only by forming the through hole  24  into which the shaft  23   c  is inserted, it is not necessary to form a plurality of screw holes in the inner wall surface of the transfer unit  11  in order to install the adaptor  23 . As a result, as shown in  FIG. 6 , since an interference between a ceiling portion  11   a  of the transfer unit  11  and a machining tool  28  is not needed, a large degree of freedom in formation position of each through hole  24  and a large degree of freedom in arrangement of the coil  18  attached to each adaptor  23 , which is position-determined by each through hole  24 , can be secured. Therefore, the plurality of coils  18  can be uniformly arranged in each transfer unit  11 , thereby realizing the smooth movement of the slide box  17  disposed between the pair of coil arrays  15 . 
     In the above-described transfer module  12 , since the O-ring  23   e  surrounding the shaft  23   c  seals the inside of the transfer unit  11  from the outside thereof, the circumferential length of the O-ring can be shortened as compared with the case where the O-ring is disposed in the seal groove formed on the inner wall surface of the transfer unit  11 . As a result, the possibility that the O-ring is broken or has a compression defect can be reduced, which improves the sealing capability of the inside of the transfer unit  11  from the outside thereof. 
     Further, in the above-described transfer module  12 , since the shaft  23   c  is male-threaded and the nut  25  is screw-coupled to the portion of the shaft  23   c  protruding from the through hole  24  so that the adaptor  23  is tightly fixed to the transfer unit  11 , it is not necessary to additionally form screw holes or the like for fixing the adaptor  23  in the transfer unit  11 . Thus, the interference between the ceiling portion  11   a  of the transfer unit  11  and the machining tool  28  does not need to be considered securely. 
     In transfer modules using the conventional linear motor mechanism, since the coils are arranged in the transfer space that is under a depressurized environment, the heat generated when the electromagnetic force is generated cannot be removed by convection of air. Thus, in order to suppress the heat generation amount of the coils, the coils only generate an electromagnetic force at just several ten percent of the rated power, which lowers electromagnetic driving efficiency of the slide box  17 . 
     In the above-described transfer module  12 , a cooling mechanism is installed in the adaptor  23  in order to cool the coil  18 . Specifically, a coolant channel  23   g  is formed inside the base portion  23   a  of the adaptor  23 , a hollow portion  23   h  is formed to penetrate through the shaft  23   c  in the axial direction, and a tubular coolant supply path  26  is disposed to pass through the hollow portion  23   h  and reach the coolant channel  23   g.  The coolant supply path  26  circularly supplies the coolant channel  23   g  with a coolant, for example, cold water or cold air, thereby cooling the adaptor  23  and further cooling the coil  18 . 
     Accordingly, since it is not necessary to consider the heat generated when the electromagnetic force is generated by the coils  18 , the coils  18  can generate the electromagnetic forces almost at the rated power, and thus, the electromagnetic driving efficiency of the slide box  17  can be improved. 
     In addition, the adaptor  23  has a power supply line  27 , which passes through the hollow portion  23   h  and the base portion  23   a  to reach the electric contact  23   f  from outside the transfer unit  11 . Accordingly, a through hole for the power supply line  27  does not need to be additionally formed in the transfer unit  11 , thereby more securely removing the need to consider the interference between the ceiling portion  11   a  of the transfer unit  11  and the machining tool  28 . 
     In transfer modules using the conventional linear motor mechanism, since each coil is a part separate from the transfer unit, misalignment easily occurs when each coil  18  is installed on the transfer unit. For example, as shown in  FIG. 7A , when each coil is misaligned by an angle θ in the rotational direction with respect to the arrangement direction of the each transfer unit (as shown by broken lines), with regard to each one of the coils, a distance between the coil and the permanent magnet of the transfer base is varied according to portions in the coil, which makes the electromagnetic driving force acting on the permanent magnets and further the transfer base unstable. In addition, since the misalignment amount L×θ (wherein L is a length of the coil in the arrangement direction) in one coil is accumulated by the number of the coils in the coil array and influences on the movement of the transfer base, it is likely that the transfer base cannot move in a desired direction. 
     However, in the above-described transfer module  12 , since each adaptor  23  is position-determined with respect to the transfer unit  11  only by the single shaft  23   c,  the adaptor  23  can be freely rotated about the shaft  23   c,  and thus the misalignment in the rotational direction can be resolved by easily rotating the adaptor  23  and further the coil  18  with respect to the arrangement direction of each transfer unit  11 . For example, as shown in  FIG. 7B , by bringing a straight lateral surface of a jig  29  into contact with the respective adaptors  23  after the adaptors  23  are installed on the transfer unit  11 , the misalignment in rotational direction can be resolved by rotating the adaptors  23 . As a result, the electromagnetic force acting on the slide box  17  can be stabilized and the slide box  17  can be securely moved in a desired direction. 
     Hereinabove, while the present disclosure has been described with the embodiments, the present disclosure is not limited to the above-described embodiments. 
     As shown in  FIG. 8 , the stopper  23   b  does not need to be necessarily installed on the adaptor  23 . In this case, since a degree of freedom in position-determination of the coil  18  with respect to the adaptor  23  is increased, for example, when the coil  18  is misaligned in the rotational direction with respect to the arrangement direction of the transfer units  11 , the misalignment in rotational direction may be resolved by rotating the coil  18 , instead of rotating the adaptor  23 . The misalignment in the rotational direction may also be resolved by rotating the adaptor  23  and also rotating the coil  18  with respect to the adaptor  23 . 
     In addition, as shown in  FIG. 9 , the adaptor  23  may be provided with another shaft  23   i  in addition to the shaft  23   c.  However, in this case, it is preferred that the other shaft  23   i  does not contribute to position-determination of the adaptor  23  in order to secure a degree of freedom in the rotational direction of the adaptor  23  with respect to the arrangement direction of the transfer units  11 . 
     The installation configuration of the coil  18  using the adaptor  23  of the transfer module  12  according to the present embodiment may be applied to not only the case where the transfer module  12  is configured with a plurality of transfer units  11  but also a case where the transfer module  12  is configured with a single transfer unit  11 , i.e., a case where the transfer module cannot be elongated. In addition, the installation configuration of the coil  18  using the adaptor  23  of the transfer module  12  according to the present embodiment can be applied when the transfer module  12  has a shape other than the rectangular parallelepiped and the plurality of process modules  13  are radially connected to the transfer module  12 . 
     According to the embodiment of the present disclosure, since a sealing member is interposed between each through hole of the transfer unit and a protrusion of each fitting part, it is not necessary to seal the gap between the inner wall surface of the transfer unit and the fitting part and to form a seal groove on the inner wall surface of the transfer unit. In addition, since the fitting part can be installed on the transfer unit only by forming the through hole  24  into which the protrusion is inserted, it is not necessary to form a plurality of screw holes in the inner wall surface of the transfer unit in order to install the fitting part. As a result, since an interference between a ceiling portion of the transfer unit and a machining tool is not needed, a large degree of freedom in formation position of each through hole and a large degree of freedom in arrangement of the coil attached to each fitting part, which is position-determined by each through hole, can be secured. Therefore, the plurality of coils can be uniformly arranged in each transfer unit, thereby realizing the smooth movement of the transfer base disposed between the pair of coil arrays. 
     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.