Patent Publication Number: US-2023154776-A1

Title: Substrate processing apparatus and image capturing method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims priority from Japanese Patent Application No. 2021-133061, filed on Aug. 18, 2021, with the Japan Patent Office, the disclosure of which is incorporated herein in its entirety by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to a substrate processing apparatus and an image capturing method. 
     BACKGROUND 
     A vertical-type thermal processing apparatus is known which includes a vertically elongated thermal processing furnace, accommodates a wafer boat in the thermal processing furnace in a state where a plurality of wafers is placed on the wafer boat, and performs a thermal processing for heating the wafers. In the vertical-type thermal processing apparatus, a wafer transfer device having a plurality of forks simultaneously transfers a plurality of wafers stored in a carrier to the wafer boat (see, e.g., Japanese Laid-Open Patent Publication No. 2019-046843). 
     SUMMARY 
     According to an aspect of the present disclosure, a substrate processing apparatus includes: a chamber configured to accommodate a boat; a transfer mechanism provided inside the chamber, and configured to transfer a substrate; a first camera configured to capture an image of a support column of the boat and the substrate; a support member inserted through an opening formed in a wall surface of the chamber, and configured to support the first camera; and a driver configured to drive the support member in order to move the first camera between a standby position and a measurement position. 
     The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an example of a perspective view of a thermal processing apparatus when viewed from a rear side. 
         FIG.  2    is a vertical cross-sectional view schematically illustrating an example of a substrate processing system according to an embodiment. 
         FIG.  3    is a perspective view schematically illustrating an example of a loading area. 
         FIG.  4    is a hardware configuration diagram of an example of a computer. 
         FIG.  5    is a view illustrating an example of a functional configuration of a control device. 
         FIG.  6    is a flowchart of an example of a process for controlling a moving operation of a transfer mechanism according to an embodiment. 
         FIGS.  7 A and  7 B  are views illustrating an example of a position change in a moving operation of a fork when a wafer W is acquired or placed. 
         FIG.  8    is an image view of an example of a boat into which a fork is inserted. 
         FIG.  9    is a flowchart of an example of an automatic teaching process for a fork according to an embodiment. 
         FIG.  10    is an image view of an example of a boat when forks are inserted to reach a position P 5 . 
         FIG.  11    is a flowchart of an example of an automatic teaching process for a boat according to an embodiment. 
         FIG.  12    is an image view of an example of a boat when a fork is inserted to reach positions TCH and P 3 . 
         FIGS.  13 A and  13 B  are views illustrating an example of a camera. 
         FIGS.  14 A and  14 B  are views illustrating another example of the camera. 
         FIG.  15    is a top view illustrating an example of the thermal processing apparatus during a carry-in of the boat. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made without departing from the spirit or scope of the subject matter presented here. 
     Hereinafter, embodiments for implementing the present disclosure will be described with reference to the drawings. In the respective drawings, the same components will be denoted by the same reference numerals, and overlapping descriptions thereof may be omitted. 
       FIG.  1    is an example of a perspective view of a thermal processing apparatus  10  when viewed from rear side.  FIG.  2    is a vertical cross-sectional view schematically illustrating an example of a substrate processing system according to an embodiment.  FIG.  3    is a perspective view schematically illustrating an example of a loading area. As illustrated in  FIG.  2   , the substrate processing system includes a thermal processing apparatus  10  and a control device  100 . The control device  100  may be provided inside the housing of the thermal processing apparatus  10  as a portion of the configuration of the thermal processing apparatus  10 , or may be provided outside the housing of the thermal processing apparatus  10  as a separate portion from the configuration of the thermal processing apparatus  10 . For example, the control device  100  may be implemented by using, for example, a server device connected for a data communication via a network or a cloud service available via a network. 
     As illustrated in  FIG.  2   , the thermal processing apparatus  10  includes a vertical thermal processing furnace  60  to be described later, holds and accommodates a plurality of wafers W on a boat at predetermined intervals along the vertical direction, and may perform various types of thermal processing such as oxidation, diffusion, and decompressed CVD on the wafers W. Hereinafter, descriptions will be made on an example where the present disclosure is applied to the thermal processing apparatus  10  which supplies a processing gas to wafers W provided in a processing container  65  to be described later, thereby oxidizing the surfaces of the wafers W. Each wafer W is an example of a substrate to be processed. The substrate to be processed is not limited to a circular wafer W. 
     The thermal processing apparatus  10  of  FIG.  2    includes a stage (load port)  20 , a housing  30 , and the control device  100 . The stage (load port)  20  is provided on the front portion of the housing  30 . The housing  30  includes a loading area (work area)  40  and the thermal processing furnace  60 . 
     The loading area  40  is provided in the lower portion inside the housing  30 . The thermal processing furnace  60  is provided above the loading area  40  inside the housing  30 . A base plate  31  is provided between the loading area  40  and the thermal processing furnace  60 . 
     The stage (load port)  20  is provided to carry the wafers W into and out from the housing  30 . Storage containers  21  and  22  are placed on the stage (load port)  20 . Each of the storage containers  21  and  22  is a closed storage container (front opening unified pod; FOUP) provided with a removable cover on the front face thereof, and capable of storing a plurality of (e.g., about 25) wafers W at predetermined intervals. 
     An alignment device (aligner)  23  may be provided below the stage  20  to align cutout portions (e.g., notches) formed in the outer peripheries of the wafers W transferred by a transfer mechanism  47  to be described later, in one direction. 
     The loading area (work area)  40  is provided to transfer the wafers W between the storage containers  21  and  22  and a boat  44  to be described later, so that the boat  44  is carried into the processing container  65  (loading), and is carried out from the processing container  65  (unloading). In the loading area  40 , door mechanisms  41 , a shutter mechanism  42 , a lid  43 , the boat  44 , bases  45   a  and  45   b , a lifting mechanism  46 , and the transfer mechanism  47  are provided. 
     The door mechanisms  41  are provided to remove the covers of the storage containers  21  and  22 , and open the storage containers  21  and  22  and the loading area  40  to communicate with each other. The shutter mechanism  42  is provided in the upper portion of the loading area  40 . The shutter mechanism  42  is provided to cover (or block) a furnace opening  68   a  to be described later, in order to suppress or prevent the heat inside the high temperature furnace from being released into the loading area  40  through the furnace opening  68   a , when the lid  43  is opened. 
     The lid  43  includes a heat insulating cylinder  48  and a rotation mechanism  49 . The heat insulating cylinder  48  is provided on the lid  43 . The heat insulating cylinder  48  prevents the boat  44  from being cooled by the heat transfer with the side of the lid  43 , and keeps the boat  44  warm. The rotation mechanism  49  is attached to the lower portion of the lid  43 . The rotation mechanism  49  rotates the boat  44 . A rotary shaft of the rotation mechanism  49  airtightly penetrates the lid  43 , and rotates a rotary table (not illustrated) disposed on the lid  43 . 
     The lifting mechanism  46  moves the lid  43  up and down, when the boat  44  is carried from the loading area  40  into the processing container  65  and carried out from the processing container  65 . When the lid  43  moved up by the lifting mechanism  46  is carried into the processing container  65 , the lid  43  comes into contact with the furnace opening  68   a  to be described later, thereby sealing the furnace opening  68   a . The boat  44  placed on the lid  43  may rotatably hold each wafer W within a horizontal plane inside the processing container  65 . 
     The thermal processing apparatus  10  may include a plurality of boats  44 . In the present embodiment, an example where two boats  44  are provided will be described with reference to  FIG.  3   . 
     Boats  44   a  and  44   b  are provided in the loading area  40 . In the loading area  40 , the bases  45   a  and  45   b  and a boat transfer mechanism  45   c  are provided. The bases  45   a  and  45   b  are stages onto which the boats  44   a  and  44   b  are transferred, respectively, from the lid  43 . The boat transfer mechanism  45   c  transfers the boat  44   a  or  44   b  from the lid  43  onto the base  45   a  or  45   b.    
     The boats  44   a  and  44   b  are made of, for example, quartz, and mount thereon the wafers W each having a large diameter, for example, a diameter of 300 mm, in a horizontal state at predetermined intervals (pitch width) in the vertical direction. The boats  44   a  and  44   b  are formed by, for example, interposing a plurality of (e.g., three) support columns  52  between a top plate and a bottom plate. Each support column  52  is provided with supports such as grooves or claws for supporting (holding) the wafers W. The boats  44   a  and  44   b  may be appropriately provided with auxiliary columns, in addition to the support columns  52 . Each of the boats  44   a  and  44   b  is an example of a container in which the wafers W may be placed. 
     The transfer mechanism  47  transfers the wafers W between the storage container  21  or  22  and the boat  44   a  or  44   b . The transfer mechanism  47  is an example of a transfer device that transfers the wafers W. 
     The transfer mechanism  47  includes a base  57 , a lifting arm  58 , and a plurality of forks  59 . The base  57  is movable up and down and pivotable. The lifting arm  58  is movable vertically (up and down) by, for example, a ball screw. The base  57  is provided on the lifting arm  58  to be pivotable horizontally. The plurality of forks are an example of transfer plates (transfer units) that support the wafers W. 
     In the loading area  40 , cameras  80   a  and  80   b  are provided. Each of the cameras  80   a  and  80   b  is an example of an image capturing device. The camera  80   a  is provided to capture images of the direction from the transfer mechanism  47  toward the storage container  21  or  22  and the direction from the transfer mechanism  47  toward the boat  44   a  or  44   b .  FIGS.  2  and  3    illustrate an example where the camera  80   a  is provided in the movable portion of the transfer mechanism  47 . 
     For example, the camera  80   a  captures images of a moving operation in which the transfer mechanism  47  acquires (gets) the wafers W from the storage container  21  or  22 , and a moving operation in which the transfer mechanism  47  places (puts) the wafers W on the boat  44   a  or  44   b . Further, the camera  80   a  captures images of a moving operation in which the transfer mechanism  47  acquires the wafers W from the boat  44   a  or  44   b , and a moving operation in which the transfer mechanism  47  places the wafers W in the storage container  21  or  22 . 
     In  FIGS.  2  and  3   , the camera  80   b  is provided to capture an image of the rear surface of the boat  44   a  or  44   b  when viewed from the side of the transfer mechanism  47 . The camera  80   b  of  FIGS.  2  and  3    is provided in a back door  400  (see, e.g.,  FIG.  1   ) provided in the rear side wall of the housing  30  as illustrated in  FIGS.  13 A and  13 B  to be described later. 
     For example, the camera  80   b  captures an image of the moving operation in which the transfer mechanism  47  places the wafers W on the boat  44   a  or  44   b . Further, the camera  80   b  captures an image of the moving operation in which the transfer mechanism  47  acquires the wafers W from the boat  44   a  or  44   b.    
     The control device  100  controls the entire thermal processing apparatus  10 . The control device  100  controls the operation of the thermal processing apparatus  10  such that a thermal processing is performed under various processing conditions represented in a recipe. Further, as described later, the control device  100  performs, for example, a full automatic teaching process for automatizing a teaching of a transfer position of the wafers W to the transfer mechanism  47 , an autonomous automatic transfer process for autonomously controlling the transfer of the wafers W by the transfer mechanism  47  (autonomous navigation control), and an abnormality sign detecting process for supporting a preventive maintenance activity for the transfer mechanism  47 . 
     As illustrated in  FIG.  1   , the back door  400  is provided in the rear side wall of the thermal processing apparatus  10 , to transfer a replacement member such as the boat  44  into the loading area  40  (see, e.g.,  FIG.  2   ). Further, the rear surface of the thermal processing apparatus  10  is provided with accommodation portions  901  and  902  that accommodate, for example, a gas supply, an exhaust unit, and a power supply. A maintenance space is provided between the accommodation portions  901  and  902  outside the back door  400 . When the replacement member is transferred into the loading area  40 , an operator opens the back door  400 , and transfers the replacement member into the loading area  40  through the maintenance space and the back door  400 . 
     The control device  100  is implemented by, for example, a computer having the hardware configuration illustrated in  FIG.  4   .  FIG.  4    is a hardware configuration diagram of an example of the computer. 
     A computer  500  of  FIG.  4    includes, for example, an input device  501 , an output device  502 , an external interface (I/F)  503 , a random access memory (RAM)  504 , a read only memory (ROM)  505 , a central processing unit (CPU)  506 , a communication I/F  507 , and a hard disk drive (HDD)  508 , and are connected to each other by a bus B. The input device  501  and the output device  502  may be connected and used when necessary. 
     The input device  501  is, for example, a keyboard, a mouse, or a touch panel, and is used when, for example, the operator inputs each operation signal. The output device  502  is, for example, a display, and displays results of processes performed by the computer  500 . The communication I/F  507  connects the computer  500  to a network. The HDD  508  is an example of a nonvolatile storage device that stores programs or data. 
     The external I/F  503  is an interface with an external device. The computer  500  may perform reading and/or writing of a record medium  503   a  such as a secure digital (SD) memory card via the external I/F  503 . The ROM  505  is an example of a nonvolatile semiconductor memory (storage device) in which programs or data are stored. The RAM  504  is an example of a volatile semiconductor memory (storage device) that temporarily holds programs or data. 
     The CPU  506  is an arithmetic device that implements the entire control or functions of the computer  500  by reading programs or data from the storage device such as the ROM  505  or the HDD  508  onto the RAM  504  and executing processes. 
     The control device  100  may implement various functions to be described later in the manner that the computer  500  having the hardware configuration illustrated in  FIG.  4    executes processes according to programs. 
     &lt;Functional Configuration&gt; 
     An example of the functional configuration of the control device  100  will be described with reference to  FIG.  5   .  FIG.  5    is a view illustrating an example of the functional configuration of the control device. The control device  100  includes an image data acquisition unit  110 , an image processing unit  120 , an autonomous control unit  130 , a camera control unit  140 , a transfer device control unit  150 , a database  160 , a recipe execution unit  170 , and a wafer transfer control unit  180 . 
     The image processing unit  120  includes a wafer acquisition image processing unit  122  and a wafer placement image processing unit  124 . The autonomous control unit  130  includes a transfer teaching unit  132  and a position correction unit  134 . The functional configuration of  FIG.  5    appropriately omits the functional configuration unnecessary for the description of the present embodiment. 
     The image data acquisition unit  110  acquires image data captured by the cameras  80   a  and  80   b  (hereinafter, collectively referred to as the cameras  80  as appropriate). For example, the image data acquisition unit  110  acquires image data of the moving operation in which the transfer mechanism  47  acquires the wafers W from the storage container  21  or  22 , and the moving operation in which the transfer mechanism  47  places the wafers W on the boat  44   a  or  44   b . Further, for example, the image data acquisition unit  110  acquires image data of the moving operation in which the transfer mechanism  47  acquires the wafers W from the boat  44   a  or  44   b , and the moving operation in which the transfer mechanism  47  places the wafers W on the boat  44   a  or  44   b.    
     The image processing unit  120  performs an image processing on the image data acquired by the image data acquisition unit  110 , to analyze (measure) necessary distances (dimensions) from a position of a support such as a groove or claw of the storage container  21  or  22 , a position of a fork  59  of the transfer mechanism  47 , and a position of a wafer W, and digitize a positional relationship. In the following, descriptions will be made assuming that the supports of the storage container  21  or  22  are grooves. 
     Further, the image processing unit  120  performs an image processing on the image data acquired by the image data acquisition unit  110 , to analyze (measure) necessary distances (dimensions) from a position of a support such as a groove or claw of the boat  44   a  or  44   b , a position of a fork  59  of the transfer mechanism  47 , and a position of a wafer W, and digitize a positional relationship. In the following, descriptions will be made assuming that the supports of the boat  44   a  or  44   b  are grooves. 
     The wafer acquisition image processing unit  122  of the image processing unit  120  performs an image processing on the image data of the moving operation of acquiring the wafers W from the storage container  21  or  22 , to analyze necessary distances from a position of a groove of the storage container  21  or  22 , a position of a fork  59  of the transfer mechanism  47 , and a position of a wafer W, and digitize a positional relationship. 
     Further, the wafer acquisition image processing unit  122  of the image processing unit  120  performs an image processing on the image data of the moving operation of acquiring the wafers W from the boat  44   a  or  44   b , to analyze necessary distances from a position of a groove of the boat  44   a  or  44   b , a position of a fork  59  of the transfer mechanism  47 , and a position of a wafer W, and digitize a positional relationship. 
     The wafer placement image processing unit  124  of the image processing unit  120  performs an image processing on the image data of the moving operation of placing the wafers W on the boat  44   a  or  44   b , to analyze necessary distances from a position of a groove of the boat  44   a  or  44   b , a position of a fork  59  of the transfer mechanism  47 , and a position of a wafer W, and digitize a positional relationship. 
     Further, the wafer placement image processing unit  124  of the image processing unit  120  performs an image processing on the image data of the moving operation of placing the wafers W in the storage container  21  or  22 , to analyze necessary distances from a position of a groove of the storage container  21  or  22 , a position of a fork  59  of the transfer mechanism  47 , and a position of a wafer W, and digitize a positional relationship. 
     Based on the digitized positional relationship among the position of the groove of the storage container  21  or  22 , the position of the fork  59  of the transfer mechanism  47 , and the position of the wafer W, the autonomous control unit  130  calculates corrected teaching data for the placement position of the wafers W in the storage container  21  or  22 , and performs a teaching of the transfer position of the wafers W to the transfer mechanism  47 . For example, the corrected teaching data for the placement position of the wafers W in the storage container  21  or  22  is used to correct initial teaching data for the moving operation in which the forks  59  of the transfer mechanism  47  acquire the wafers W from the storage container  21  or  22 , or the moving operation in which the forks  59  of the transfer mechanism  47  place the wafers W in the storage container  21  or  22 . 
     Based on the digitized positional relationship among the position of the groove of the boat  44   a  or  44   b , the position of the fork  59  of the transfer mechanism  47 , and the position of the wafer W, the autonomous control unit  130  calculates corrected teaching data for the placement position of the wafers W on the boat  44   a  or  44   b , and performs a teaching of the transfer position of the wafers W to the transfer mechanism  47 . For example, the corrected teaching data for the placement position of the wafers W on the boat  44   a  or  44   b  is used to correct initial teaching data for the moving operation in which the forks  59  of the transfer mechanism  47  acquire the wafers W from the boat  44   a  or  44   b , or the moving operation in which the forks  59  of the transfer mechanism  47  place the wafers W on the boat  44   a  or  44   b.    
     Further, the autonomous control unit  130  implements an autonomous navigation process, by measuring the transfer position of the wafers W which are transferred between the storage container  21  or  22  and the boat  44   a  or  44   b  according to the corrected teaching data, at predetermined intervals, and performing a position correction to be described later when a position deviation occurs. 
     Based on the positional relationship among the position of the groove of the storage container  21  or  22 , the position of the fork  59  of the transfer mechanism  47 , and the position of the wafer W digitized by performing the image processing on the image data for the moving operation of acquiring the wafers W from the storage container  21  or  22 , the transfer teaching unit  132  of the autonomous control unit  130  calculates corrected teaching data for the placement position of the wafers W in the storage container  21  or  22 . 
     Further, based on the positional relationship among the position of the groove of the boat  44   a  or  44   b , the position of the fork  59  of the transfer mechanism  47 , and the position of the wafer W digitized by performing the image processing on the image data for the moving operation of acquiring the wafers W from the boat  44   a  or  44   b , the transfer teaching unit  132  of the autonomous control unit  130  calculates corrected teaching data for the placement position of the wafers W on the boat  44   a  or  44   b . 
     Further, based on the positional relationship among the position of the groove of the boat  44   a  or  44   b , the position of the fork  59  of the transfer mechanism  47 , and the position of the wafer W digitized by performing the image processing on the image data for the moving operation of placing the wafers W on the boat  44   a  or  44   b , the transfer teaching unit  132  of the autonomous control unit  130  calculates corrected teaching data for the placement position of the wafers W on the boat  44   a  or  44   b.    
     Further, based on the positional relationship among the position of the groove of the storage container  21  or  22 , the position of the fork  59  of the transfer mechanism  47 , and the position of the wafer W digitized by performing the image processing on the image data for the moving operation of placing the wafers W in the storage container  21  or  22 , the transfer teaching unit  132  of the autonomous control unit  130  calculates corrected teaching data for the placement position of the wafers W in the storage container  21  or  22 . 
     The position correction unit  134  of the autonomous control unit  130  implements the autonomous navigation process, by measuring the transfer position of the wafers W which are transferred between the storage container  21  or  22  and the boat  44   a  or  44   b  according to the corrected teaching data, at predetermined intervals, and performing the position correction to be described later when a position deviation occurs. 
     The camera control unit  140  controls a timing for the image capturing performed by the cameras  80   a  and  80   b , according to an instruction from the autonomous control unit  130 . The database  160  stores the initial teaching data and the corrected teaching data for teaching the placement position of the wafers W to the transfer mechanism  47  of the thermal processing apparatus  10 . Further, the database  160  stores correction data and displacement data which are used for the position correction to be described later. 
     For example, the initial teaching data is preset in the thermal processing apparatus  10 , and is set for each apparatus type of the thermal processing apparatus  10 . The corrected teaching data is teaching data obtained by correcting a positional deviation of the placement position of the wafers W caused from a machine difference of the thermal processing apparatus  10  or a variation of adjustment by the operator. The correction data is used for continuing to transfer the wafers W while correcting an occurring positional deviation of the placement position of the wafers W, based on results obtained by periodically measuring the transfer position of the wafers W transferred according to the corrected teaching data. The displacement data is obtained by continuously recording an occurring positional deviation of the placement position of the wafers W, and is used for analyzing various aspects (e.g., a trend, a behavior, a failure, and an abnormality). 
     The transfer device control unit  150  controls the moving operation of the transfer mechanism  47  according to a control from the autonomous control unit  130  or the wafer transfer control unit  180 . The transfer device control unit  150  controls the moving operation of the transfer mechanism  47 , by using the initial teaching data, the corrected teaching data, and the correction data stored in the database  160 . 
     The recipe execution unit  170  controls the operation of the thermal processing apparatus  10  such that a thermal processing is performed under processing conditions represented in a recipe. The wafer transfer control unit  180  instructs the transfer device control unit  150  to transfer the wafers W between the storage container  21  or  22  and the boat  44   a  or  44   b , according to a control from the recipe execution unit  170 . 
     &lt;Process&gt; 
     Hereinafter, descriptions will be made on an example of the full automatic teaching process for automatizing the teaching of the transfer mechanism  47  that transfers the wafers W between the storage container  21  or  22  and the boat  44   a  or  44   b , and the autonomous transfer process for autonomously controlling the transfer of the wafers W by the transfer mechanism  47  (autonomous navigation control). The control device  100  controls the moving operation of the transfer mechanism  47  according to, for example, the procedure of  FIG.  6   .  FIG.  6    is a flowchart of an example of the process of controlling the moving operation of the transfer mechanism according to the present embodiment. 
     In step S 10 , the control device  100  performs a confirmation process prior to a transfer operation. The confirmation process prior to the transfer operation in step S 10  is performed before the transfer operation, and is a process of performing the moving operation of the forks  59  of the transfer mechanism  47  based on the initial teaching data without transferring the wafers W, so as to confirm the transfer position between the storage container  21  or  22  and the boat  44   a  or  44   b.    
     In the present embodiment, for example,  FIGS.  7 A and  7 B  define a position change in the moving operation of the forks  59  when the wafers W are acquired from a placement position or placed at a placement position, and a position where the cameras  80  capture images. 
       FIGS.  7 A and  7 B  are views illustrating an example of the position change in the moving operation of the forks when the wafers W are acquired or placed.  FIG.  7 A  illustrates an example of the position change in the moving operation of the forks  59  when the wafers W are acquired.  FIG.  7 B  illustrates an example of the position change in the moving operation of the forks  59  when the wafers W are placed. 
     For example,  FIG.  7 A  represents an example of the moving operation in which the forks  59  are moved along the positions P 4 →P 3 →P 2 →P 5 →P 1  in this order. The position P 3  in  FIG.  7 A  is an example of a first position, and is, for example, a position immediately before the forks  59  acquire the wafers W from the boat  44   a  or  44   b . The position TCH is, for example, a position where the forks  59  acquire the wafers W from the boat  44   a  or  44   b . The position P 2  is, for example, a position after the forks  59  acquire the wafers W from the boat  44   a  or  44   b.    
     For example,  FIG.  7 B  represents an example of the moving operation in which the forks  59  are moved along the positions P 1 →P 5 →P 3 →P 4  in this order. The position P 5  of  FIG.  7 B  is an example of a second position, and is, for example, a position immediately before the forks  59  place the wafers W on the boat  44   a  or  44   b . The position TCH is, for example, a position where the forks  59  place the wafers W on the boat  44   a  or  44   b . The position P 3  is, for example, a position after the forks  59  place the wafers W on the boat  44   a  or  44   b.    
     The confirmation process prior to the transfer operation for the boat is performed according to, for example, the following procedure. The autonomous control unit  130  of the control device  100  reads the initial teaching data from the database  160 . Based on the initial teaching data, the autonomous control unit  130  controls the transfer device control unit  150  to insert the forks  59  to reach the position P 3  of the boat  44   a.    
     The autonomous control unit  130  performs a control such that the cameras  80  capture images at the positions P 3  and P 5  of the boat  44   a . The image data acquisition unit  110  acquires image data captured by the cameras  80  at the positions P 3  and P 5  of the boat  44   a . The image processing unit  120  performs an image processing on the image data captured at the positions P 3  and P 5  of the boat  44   a , to measure a distance between the upper portion of a groove of the support columns  52  of the boat  44   a  (hereinafter, referred to as a boat groove) and the wafer mounting surface of a fork  59 . The image processing unit  120  measures a distance between the edge of the boat groove and the edge of the fork  59 . 
     The autonomous control unit  130  determines whether the measured distance between the upper portion of the boat groove and the wafer mounting surface of the fork  59  and the measured distance between the edge of the boat groove and the edge of the fork  59 , at the positions P 3  and P 5  of the boat  44   a , satisfy design reference values. When it is determined that the design reference values are not satisfied, the autonomous control unit  130  performs a correction operation for the errors, so as to perform the position correction such that the moving operation of the forks  59  satisfies the design reference values. The autonomous control unit  130  performs a feedback by storing the corrected teaching data in the database  160  according to the result of the position correction of the moving operation of the forks  59  performed to satisfy the design reference values. 
     After the confirmation process prior to the transfer operation for the boat, the control device  100  performs a confirmation process prior to a transfer operation for the storage container. Since the size of a groove of the storage container  21  (hereinafter, referred to as a storage container groove) is sufficiently larger than that of the boat groove, the confirmation operation prior to the transfer operation for the storage container may be omitted. 
     The autonomous control unit  130  of the control device  100  reads the initial teaching data from the database  160 . Based on the initial teaching data, the autonomous control unit  130  controls the transfer device control unit  150  to insert the forks  59  to reach the position P 3  of the storage container  21 . 
     The autonomous control unit  130  performs a control such that the camera  80   a  captures images at the positions P 3  and P 5  of the storage container  21 . The image data acquisition unit  110  acquires image data captured by the camera  80   a  at the positions P 3  and P 5  of the storage container  21 . The image processing unit  120  performs an image processing on the image data captured at the positions P 3  and P 5  of the storage container  21 , to measure a distance between the upper portion of the storage container groove and the wafer mounting surface of the fork  59 . The image processing unit  120  measures a distance between the edge of the storage container groove and the edge of the fork  59 . 
     The autonomous control unit  130  determines whether the measured distance between the upper portion of the storage container groove and the wafer mounting surface of the fork  59 , and the measured distance between the edge of the storage container groove and the edge of the fork  59 , at the positions P 3  and P 5  of the storage container  21 , satisfy design reference values. When it is determined that the design reference values are not satisfied, the autonomous control unit  130  performs a correction operation for the errors, so as to perform the position correction such that the moving operation of the forks  59  satisfy the design reference values. The autonomous control unit  130  performs a feedback by storing the corrected teaching data in the database  160  according to the result of the position correction of the moving operation of the forks  59  performed to satisfy the design reference values. 
     In step S 12 , the control device  100  performs the automatic teaching process. In the automatic teaching process of step S 12 , the moving operation of the forks  59  of the transfer mechanism  47  is performed based on the corrected teaching data obtained by correcting the initial teaching data by the confirmation process prior to the transfer operation in step S 10 . 
     The control device  100  acquires image data obtained by capturing images of the moving operation in which the forks  59  of the transfer mechanism  47  acquire the wafers W from the storage container  21  or  22 , and digitizes the positional relationship among the groove of the storage container  21  or  22 , the fork  59 , and the wafer W through an image processing. Based on the digitized positional relationship among the groove of the storage container  21  or  22 , the fork  59 , and the wafer W, the control device  100  outputs the corrected teaching data for correcting the placement position of the wafers W in the storage container  21  or  22  (correcting the moving operation of the forks  59 ). 
     Further, the control device  100  acquires image data obtained by capturing images of the moving operation in which the forks  59  of the transfer mechanism  47  place the wafers W on the boat  44   a  or  44   b , and digitizes the positional relationship among the groove of the boat  44   a  or  44   b , the fork  59 , and the wafer W through an image processing. The positional relationship among the groove of the boat  44   a  or  44   b , the fork  59 , and the wafer W may be called, for example, a fitting dimension of the boat  44   a  or  44   b  and the wafers W. 
     Based on the digitized positional relationship among the groove of the boat  44   a  or  44   b , the fork  59 , and the wafer W, the control device  100  outputs the corrected teaching data for correcting the placement position of the wafers W on the boat  44   a  or  44   b  (correcting the moving operation of the forks  59 ). The details of the automatic teaching process in step S 12  will be described later. 
     In step S 14 , the control device  100  controls the moving operation of the transfer mechanism  47  and performs the transfer process of the wafers W, by using the corrected teaching data stored in the database  160 , thereby operating the thermal processing apparatus  10 . In the present embodiment, step  16  and its subsequent processes are performed at predetermined intervals such as regular intervals under the operation of the thermal processing apparatus  10 . 
     In step S 16 , the autonomous control unit  130  performs a control such that the cameras  80   a  and  80   b  capture images at the position P 3  or P 5  of the boat  44   a . For example, as illustrated in  FIG.  8   , the image data acquisition unit  110  acquires image data captured by the cameras  80   a  and  80   b  at the position P 3  or P 5  of the boat  44   a .  FIG.  8    is an image view of an example of the boat into which a fork is inserted. As illustrated in  FIG.  8   , the cameras  80   a  and  80   b  are provided to capture images of boat grooves at three points of the boat  44   a.    
     In step S 18 , the image processing unit  120  performs an image processing on the image data captured by the cameras  80   a  and  80   b  at the position P 3  or P 5  of the boat  44   a , to digitize a positional relationship between the boat groove and the wafer W. 
     For example, the image processing unit  120  performs an image processing on the image data captured by the cameras  80   a  and  80   b  at the position P 5 , to measure, for example, a distance “a” between the lower surface of the wafer W held by the fork  59  and the upper surface of the boat groove, and a distance “b” between the support column  52  and the edge of the wafer W. The image processing unit  120  performs an image processing on the image data captured by the cameras  80   a  and  80   b  at the position P 3 , to measure, for example, the distance “a” between the lower surface of the wafer W held by the fork  59  and the upper surface of the boat groove, and the distance “b” between the support column  52  and the edge of the wafer W. 
     In step S 20 , the autonomous control unit  130  compares the digitized positional relationship between the boat groove and the wafer W, with a design reference value, for each of the boat grooves of the three points. In step S 22 , the autonomous control unit  130  determines whether the design reference value is satisfied for each of the boat grooves of the three points. 
     For example, the autonomous control unit  130  compares the distance “a” digitized in step S 18  between the lower surface of the wafer W held by the fork  59  and the upper surface of the boat groove, with a distance “a” of the design reference value, and determines whether the design reference value is satisfied at each of the boat grooves of the three points, according to the difference of the distances “a.” When the difference between the digitized distance “a” between the lower surface of the wafer W held by the fork  59  and the upper surface of the boat groove, and the distance “a” of the design reference value falls within a predetermined range (e.g., less than 200 μm), the autonomous control unit  130  determines the distance “a” to be a normal value that satisfies the design reference value. 
     When the difference between the digitized distance “a” between the lower surface of the wafer W held by the fork  59  and the upper surface of the boat groove and the distance “a” of the design reference value falls within a predetermined range (e.g., 200 μm or more and less than 400 μm), the autonomous control unit  130  determines the distance “a” to be an adjustment recommendation value that does not satisfy the design reference value. When the difference between the digitized distance “a” between the lower surface of the wafer W held by the fork  59  and the upper surface of the boat groove and the distance “a” of the design reference value falls within a predetermined range (e.g., 400 μm or more), the autonomous control unit  130  determines the distance “a” to be an abnormal value that does not satisfy the design reference value. 
     For example, the autonomous control unit  130  compares the distance ‘b” digitized in step S 18  between the edge of the wafer W held by the fork  59  and the support column  52  with a distance “b” of the design reference value, and determines whether the design reference value is satisfied at each of the boat grooves of the three points, according to the difference of the distances “b.” When the difference between the digitized distance “b” between the edge of the wafer W held by the fork  59  and the support column  52  and the distance “b” of the design reference value falls within a predetermined range (e.g., less than 200 μm), the autonomous control unit  130  determines the distance “b” to be a normal value that satisfies the design reference value. 
     When the difference between the digitized distance “b” between the edge of the wafer W held by the fork  59  and the support column  52  and the distance “b” of the design reference value falls within a predetermined range (e.g., 200 μm or more and less than 400 μm), the autonomous control unit  130  determines the distance “b” to be an adjustment recommendation value that does not satisfy the design reference value. When the difference between the digitized distance “b” between the edge of the wafer W held by the fork  59  and the support column  52  and the distance “b” of the design reference value falls within a predetermined range (e.g., 400 μm or more), the autonomous control unit  130  determines the distance “b” to be an abnormal value that does not satisfy the design reference value. 
     When the design reference value is satisfied at one or more of the boat grooves, the autonomous control unit  130  performs the process of step S 24 . In step S 24 , the autonomous control unit  130  performs a feedback by storing the correction data for correcting the corrected teaching data in the database  160 , according to the result of the position correction of the moving operation of the forks  59  performed to satisfy the design reference value by performing the correction operation for the difference (positional deviation). Accordingly, the autonomous control unit  130  may continue the operation of the thermal processing apparatus  10  while correcting the position of the moving operation of the forks  59  to satisfy the design reference value. 
     While  FIG.  6    describes, for example, the process in which the operation of the thermal processing apparatus  10  is continued while correcting the position of the moving operation of the forks  59  as long as one or more of the boat grooves of the three points has the normal value that satisfies the design reference, the present disclosure is not limited thereto. For example, when the boat grooves of the three points do not satisfy the design reference, but fall within the range of the adjustment recommendation value, the autonomous control unit  130  may continue the operation of the thermal processing apparatus  10  while correcting the position of the moving operation of the forks  59  until a processing of a batch which is being processed is completed. Further, when one or more of the boat grooves of the three points fall within the range of the abnormal value that does not satisfy the design reference, the autonomous control unit  130  may stop the operation of the thermal processing apparatus  10  before the processing of the batch which is being processed is completed. 
     When the design reference value is not satisfied at the boat grooves of the three points, the autonomous control unit  130  returns to the process of step S 12 , and performs the automatic teaching process illustrated in  FIGS.  9  to  12   . 
       FIG.  9    is a flowchart of an example of the automatic teaching process for the boat according to the present embodiment. In step S 80 , the autonomous control unit  130  of the control device  100  reads the corrected teaching data from the database  160 . 
     In step S 82 , based on the corrected teaching data, the autonomous control unit  130  controls the transfer device control unit  150 , to insert the forks  59  to reach the position P 5  of the boat  44   a . According to the corrected teaching data, the transfer device control unit  150  controls the moving operation of the transfer mechanism  47  to insert the forks  59  to reach the position P 5  of the boat  44   a  as illustrated in, for example,  FIG.  10   .  FIG.  10    is an image view of an example of the boat when the forks are inserted to reach the position P 5 . 
     In step S 84 , the autonomous control unit  130  performs a control such that the camera  80   a  captures images at the position P 5  of the boat  44   a . The image data acquisition unit  110  acquires image data captured by the camera  80   a  at the position P 5  of the boat  44   a.    
     In step S 86 , the image processing unit  120  performs an image processing on the image data captured by the camera  80   a  at the position P 5  of the boat  44   a , to digitize the positional relationship among the boat groove, the fork  59 , and the wafer W. 
     For example, the image processing unit  120  performs an image processing on the image data captured by the camera  80   a  at the position P 5 , to measure, for example, the distance “a” between the lower surface of the wafer W held by the fork  59  and the upper surface of the boat groove, and the distance “b” between the support column  52  and the edge of the wafer W. 
     In step S 88 , the autonomous control unit  130  determines whether the measured distances satisfy design reference values. When the design reference values are not satisfied, the autonomous control unit  130  performs a correction operation for the difference in step S 90 , and repeatedly performs the position correction of the moving operation of the forks  59  until the design reference values are satisfied. 
     When the design reference values are satisfied, the autonomous control unit  130  proceeds to the process of step S 92 . The autonomous control unit  130  performs a control such that the camera  80   b  captures an image at the position P 5  of the boat  44   a . The image data acquisition unit  110  acquires image data captured by the camera  80   b  at the position P 5  of the boat  44   a.    
     In step S 94 , the image processing unit  120  performs an image processing on the image data captured by the camera  80   b  at the position P 5  of the boat  44   a , to digitize the positional relationship among the boat groove, the fork  59 , and the wafer W. 
     For example, the image processing unit  120  performs an image processing on the image data captured by the camera  80   b  at the position P 5 , to measure, for example, the distance “a” between the lower surface of the wafer W held by the fork  59  and the upper surface of the boat groove, and the distance “b” between the support column  52  and the edge of the wafer W. 
     In step S 96 , the autonomous control unit  130  determines whether the measured disclosures satisfy design reference values. When the design reference values are not satisfied, the autonomous control unit  130  performs a correction operation for the difference in step S 98 , and repeatedly performs the position correction of the moving operation of the forks  59  until the design reference values are satisfied. 
     In step S 100 , the autonomous control unit  130  performs a feedback by storing the corrected teaching data in the database  160 , according to the result of the position correction of the moving operation of the forks  59  performed to satisfy the design reference values. 
       FIG.  11    is a flowchart of an example of the automatic teaching process for the boat according to the present embodiment. In step S 110 , the autonomous control unit  130  of the control device  100  reads the corrected teaching data from the database  160 . 
     In step S 112 , based on the corrected teaching data, the autonomous control unit  130  controls the transfer device control unit  150  to move the forks  59  to the position TCH of the boat  44   a . According to the corrected teaching data, the transfer device control unit  150  controls the moving operation of the transfer mechanism  47  to move the forks  59  to the position TCH of the boat  44   a  as illustrated in, for example,  FIG.  12   . 
       FIG.  12    is an image view of an example of the boat when the fork is inserted to reach the positions TCH and P 3 . As illustrated in  FIG.  12   , the cameras  80   a  and  80   b  are provided to capture images of the boat grooves at the three points of the boat  44   a.    
     In step S 114 , the autonomous control unit  130  performs a control such that the cameras  80   a  and  80   b  capture images at the position TCH of the boat  44   a . The image data acquisition unit  110  acquires image data captured by the cameras  80   a  and  80   b  at the position TCH of the boat  44   a.    
     In step S 116 , the image processing unit  120  performs an image processing on the image data captured by the cameras  80   a  and  80   b  at the position TCH of the boat  44   a , to digitize the positional relationship among the boat groove, the fork  59 , and the wafer W for the boat grooves of the three points. 
     For example, the image processing unit  120  performs an image processing on the image data captured by the cameras  80   a  and  80   b  at the position TCH, to measure, for example, the distance between the lower surface of the wafer W held by the fork  59  and the upper surface of the boat groove, and the distance between the support column  52  and the edge of the wafer W. 
     In step S 118 , the autonomous control unit  130  determines whether the measured disclosures satisfy design reference values. When the design reference values are not satisfied, the autonomous control unit  130  performs a correction operation for the difference in step S 120 , and repeatedly performs the position correction of the moving operation of the forks  59  until the design reference values are satisfied. 
     When the design reference values are satisfied, the autonomous control unit  130  proceeds to the process of step S 124 . The autonomous control unit  130  performs a control such that the cameras  80   a  and  80   b  capture images at the position P 3  of the boat  44   a . The image data acquisition unit  110  acquires the image data captured by the cameras  80   a  and  80   b  at the position P 3  of the boat  44   a.    
     In step S 126 , the image processing unit  120  performs an image processing on the image data captured by the cameras  80   a  and  80   b  at the position P 3  of the boat  44   a , to digitize the positional relationship among the boat groove, the fork  59 , and the wafer W for the boat grooves of the three points. 
     For example, the image processing unit  120  performs an image processing on the image data captured by the cameras  80   a  and  80   b  at the position P 3 , to measure, for example, the distance between the lower surface of the wafer W held by the fork  59  and the wafer mounting surface of the fork  59 , and the distance between the support column  52  and the edge of the wafer W. 
     In step S 128 , the autonomous control unit  130  determines whether the measured disclosures satisfy design reference values. When the design reference values are not satisfied, the autonomous control unit  130  performs a correction operation for the difference in step S 130 , and repeatedly performs the position correction of the moving operation of the forks  59  until the design reference values are satisfied. 
     In step S 132 , the autonomous control unit  130  performs a feedback by storing the corrected teaching data in the database  160 , according to the result of the position correction of the moving operation of the forks  59  performed to satisfy the design reference values. 
     The accuracy of the process in the flowcharts illustrated in  FIGS.  9  and  11    may be further improved by dividing the boat  44   a  into two upper and lower areas or three or more areas according to the height, and performing the process for each area. 
     According to the present embodiment, step S 16  and its subsequent processes are performed at predetermined intervals under the operation of the thermal processing apparatus  10 , so that the operation of the thermal processing apparatus  10  may be continued while correcting the position of the moving operation of the forks  59  to satisfy the design reference values. Thus, according to the present embodiment, the mean time between failures (MTBF) may be extended, and the operation rate may be improved so that the added value of the thermal processing apparatus  10  may be improved. Further, according to the present embodiment, the mean time to recovery (MTTR) may be reduced, and the operation rate and the quality may be improved so that the added value of the thermal processing apparatus  10  may be improved. 
     According to the present embodiment, for example, the behaviors of the transfer mechanism  47  and the boat  44  may be grasped by analyzing the displacement data stored in the database  160 . Further, according to the present embodiment, an abnormality detection and a failure detection are facilitated by analyzing the displacement data stored in the database  160 , so that the added value of the thermal processing apparatus  10  may be improved. For example, a thermal variation behavior of the thermal processing apparatus  10  may be logged by analyzing the displacement data stored in the database  160 , so that it is possible to predict whether the variation data exceeds a physical variation amount indicated by a mechanical design before the exceeding, and therefore, an appropriate time for the maintenance may be notified. 
     According to the autonomous transfer process of the present embodiment, the MTBF caused by the transfer of the wafers W may be extended without exceeding a physical limit of the transfer mechanism  47  or a film formation distribution limit of a process. The film formation distribution limit of the process may be detected from, for example, a limit of an adjustment by an eccentric optimizer function. 
     According to the present embodiment, for example, a time for an adjustment work at the time of a start-up (installation of an apparatus) or after a replacement of a quartz jig may be reduced, as compared with an adjustment work by an operator, and further, a transfer margin resulting from a highly accurate adjustment may be increased. According to the present embodiment, it may be expected that the MTBF (mean time between failures) is extended as a result of the increase of the transfer margin, so that the added value of the thermal processing apparatus  10  may be improved. 
     In the present embodiment, an image processing is performed to digitize the positional relationship among the position of a support such as a groove or claw of the storage container  21  or  22 , the position of a support such as a groove or claw of the boat  44   a  or  44   b , the position of the fork  59  of the transfer mechanism  47 , and the position of the wafer W. However, for example, an optical sensor may be used in combination. In the present embodiment, centering of the wafers W on the boat  44   a  or  44   b  may be implemented, and the inclination of the boat  44   a  or  44   b  based on the transfer mechanism  47  may be analyzed through a calculation. In the present embodiment, the positional deviation of the wafer W held by the fork  59  is analyzed from the image data captured by the camera  80   b , and the difference of the positional deviation is corrected, so that the transfer of the wafers W may be continued. 
     In the embodiment described above, a so-called ladder boat is described in which a plurality of support columns is provided between a top plate and a bottom plate which are vertically arranged while facing each other, and a plurality of grooves is formed on the inner side surface of each support column, such that the peripheral edge of a wafer W is inserted into the grooves. However, the present disclosure is not limited to the shape of the ladder boat. 
     For example, the present disclosure may be applied to a so-called ring boat in which a plurality of support columns is provided between a top plate and a bottom plate which are vertically arranged while facing each other, and is provided with ring members each having a flat support surface to support a wafer W on the support surface of each ring member. The present disclosure may also be applied to other boats having a specific shape. 
     Next, the camera  80   b  will be further described with reference to  FIGS.  13 A and  13 B .  FIGS.  13 A and  13 B  are views illustrating an example of the camera  80   b .  FIG.  13 A  illustrates a state where the camera  80   b  is disposed in a standby position, and  FIG.  13 B  illustrates a state where the camera  80   b  is disposed in a measurement position.  FIGS.  13 A and  13 B  are plan views of the camera  80   b , the support columns  52  of the boat  44 , and the wafer W when viewed from above. 
     The back door  400  is provided in the rear side wall of the housing  30  forming the loading area  40 , to transfer the replacement member such as the boat  44  into the loading area  40 . The back door  400  is provided in the side wall (the rear side wall) opposite to the side wall (front side wall) on which the door mechanism  41  (see, e.g.,  FIG.  2   ) is provided, among the side walls of the housing  30 . In other words, the back door  400  is provided opposite to the transfer mechanism  47  with respect to the boat  44 , in the transfer direction of the transfer mechanism  47  when the wafers W are transferred to the boat  44 . In the back door  400 , openings  401 A and  401 B are provided. 
     The camera  80   b  includes camera bodies  801 A and  801 B, a support member  802 , a drive unit  803 , mirrors  804 A and  804 B, translucent members  805 A and  805 B, and bellows  806 A and  806 B. 
     The camera  80   b  includes the camera body  801 A which is a light projecting unit, and the camera body  801 B which is a light receiving unit. In  FIGS.  13 A and  13 B , the dashed line arrows indicate the irradiation direction of light. The camera bodies  801 A and  801 B are arranged apart from each other in the horizontal direction, and are supported by the support member  802 . The camera bodies  801 A and  801 B are disposed in an air atmosphere as described later. 
     The light irradiated from the camera body  801 A passes through the translucent member  805 A, is reflected on the mirror  804 A, is further reflected on the mirror  804 B, passes through the translucent member  805 B, and is incident on the camera body  801 B. As a result, the camera  80   b  may capture an image of an object disposed between the mirrors  804 A and  804 B. The camera body  801 A is disposed in a direction in which light is irradiated in the inserting/removing direction of the opening  401 A. The camera body  801 B is disposed in a direction in which light is received in the inserting/removing direction of the opening  401 B. 
     The support member  802  is divided into two parts, such that one of the parts is inserted into the opening  401 A, and the other part is inserted into the opening  401 B. One of the divided parts of the support member  802  that is inserted into the opening  401 A supports the camera body  801 A, the mirror  804 A, and the translucent member  805 A. The other part of the support member  802  that is inserted into the opening  401 B supports the camera body  801 B, the mirror  804 B, and the translucent member  805 B. 
     The drive unit  803  drives the support member  802  in the inserting/removing direction of the openings  401 A and  401 B of the back door  400 . As a result, the drive unit  806  may move the camera bodies  801 A and  801 B between the standby position where the camera bodies  801 A and  801 B are separated from the boat  44  (see, e.g.,  FIG.  13 A ), and the measurement position where the camera bodies  801 A and  801 B approach the boat  44  (see, e.g.,  FIG.  13 B ). 
     The mirrors  804 A and  804 B are arranged inside loading area  40  having a vacuum atmosphere or an N 2  atmosphere. The mirrors  804 A and  804 B are supported by the support member  802 , and move together with the camera bodies  801 A and  801 B. The mirror  804 A reflects the light irradiated from the camera body  801 A. The mirror  804 B reflects the light reflected by the mirror  804 A to be incident on the camera body  801 B. 
     An expansible and contractable bellows  806 A is provided between the translucent member  805 A and the wall surface of the back door  400  in which the opening  401 A is formed. Further, an expansible and contractable bellows  806 B is provided between the translucent member  805 B and the wall surface of the back door  400  in which the opening  401 B is formed. The camera bodies  801 A and  801 B are arranged inside the bellows  806 A and  806 B. The translucent members  805 A and  805 B are supported by the support member  802 , and move together with the camera bodies  801 A and  801 B. The bellows  806 A and  806 B expand and contract as the camera bodies  801 A and  801 B move. As a result, the inside of the loading area  40  may be made airtight. The inside of the bellows  806 A and  806 B has the air atmosphere. That is, the camera bodies  801 A and  801 B are arranged in the air atmosphere. Meanwhile, the mirrors  804 A and  804 B are disposed in the loading area  40  having the vacuum atmosphere. The translucent members  805 A and  805 B are arranged between the air atmosphere and the vacuum atmosphere (N 2  atmosphere). 
     The configuration of the camera  80   b  is not limited to that illustrated in  FIGS.  13 A and  13 B .  FIGS.  14 A and  14 B  are views illustrating another example of the camera  80   b .  FIG.  14 A  illustrates a state where the camera  80   b  is disposed in the standby position, and  FIG.  14 B  illustrate a state where the camera  80   b  is disposed in the measurement position.  FIGS.  14 A and  14 B  are plan views of the camera  80   b , the support columns  52  of the boat  44 , and the wafer W when viewed from above. 
     An opening  401 C is formed in the back door  400 . 
     The camera  80   b  includes a camera body  801 C, a support member  802 C, a drive unit  803 C, a mirror  804 C, a translucent member  805 C, and a bellows  806 C. 
     The camera  80   b  includes the camera body  801 C which is a light receiving unit. The camera body  801 C is supported by the support member  802 C. The camera body  801 C is disposed in the air atmosphere as described later. Light of the camera body  801 C passes through the translucent member  805 C, and is reflected on the mirror  804 C, so that an image is captured in the direction indicated by the dashed line arrows of  FIGS.  14 A and  14 B . 
     The support member  802 C is inserted into the opening  401 C. The support member  802 C supports the camera body  801 C, the mirror  804 C, and the translucent member  805 C. 
     The drive unit  803 C drives the support member  802 C in the inserting/removing direction of the opening  401 C of the back door  400 . As a result, the drive unit  803 C may move the camera body  801 C between the standby position where the camera body  801 C is separated from the boat  44  (see, e.g.,  FIG.  14 A ), and the measurement position where the camera body  801 C approaches the boat  44  (see, e.g.,  FIG.  14 B ). 
     The mirror  804 C is disposed in the loading area  40  having the vacuum atmosphere or the N 2  atmosphere. 
     A stretchable bellows  806 C is provided between the translucent member  805 C and the wall surface of the back door  400  in which the opening  401 C is formed. As a result, the inside of the loading area  40  may be made airtight. The inside of the bellows  806 C has the air atmosphere. That is, the camera body  801 C is disposed in the air atmosphere. Meanwhile, the mirror  804 C is disposed in the loading area  40  having the vacuum atmosphere. The translucent member  805 C is disposed between the air atmosphere and the vacuum atmosphere (N 2  atmosphere). 
     According to the thermal processing apparatus  10  including the camera  80   b  illustrated in  FIGS.  13 A,  13 B,  14 A, and  14 B , the camera bodies  801 A,  801 B, and  801 C may be moved between the standby position where the camera bodies  801 A,  801 B, and  801 C are separated from the boat  44  (see, e.g.,  FIGS.  13 A and  14 A ) and the measurement position where the camera bodies  801 A,  801 B, and  801 C approach the boat  44  (see, e.g.,  FIGS.  13 B and  14 B ). 
     By moving the camera bodies  801 A,  801 B, and  801 C to the standby position, the camera bodies  801 A,  801 B, and  801 C may be separated from the boat  44 . As a result, the heat from the boat  44  heated inside the thermal processing furnace  60  may be suppressed from being input to the camera bodies  801 A,  801 B, and  801 C, so that the increase of the temperature of the camera bodies  801 A,  801 B, and  801 C may be prevented. 
     A downflow gas flows in the loading area  40  in order to suppress particles. By moving the camera bodies  801 A,  801 B, and  801 C to the standby position, an influence on the flow of the downflow gas may be suppressed. 
     When an image of an image capturing target (the support columns  52  of the boat  44  and the wafer W) is captured using the camera bodies  801 A,  801 B, and  801 C, the camera bodies  801 A,  801 B, and  801 C are moved to the image capturing position. As a result, the image capturing may be performed in the state where the camera bodies  801 A,  801 B, and  801 C approach the image capturing target, so that the image accuracy may be improved. 
     The camera bodies  801 A,  801 B, and  801 C are disposed inside the bellows  806 A,  806 B, and  806 C having the air atmosphere. As a result, heat generated from the camera bodies  801 A,  801 B, and  801 C may be dissipated to the air, so that the increase of the temperature of the camera bodies  801 A,  801 B, and  801 C may be prevented. Further, the camera bodies  801 A,  801 B, and  801 C may be prevented from being affected by, for example, a residual gas of the thermal processing furnace  60 . 
     A lens such as a telecentric lens may be added to the camera bodies  801 A,  801 B, and  801 C. The added lens may be disposed in the air atmosphere inside the bellows  806 A,  806 B, and  806 C. 
     Next, descriptions will be made on a case where the replacement member such as the boat  44  is transferred from the back door  400  into the loading area  40 .  FIG.  15    is an example of a top view of the thermal processing apparatus  10  when the boat  44  is carried into the loading area  40 . 
     In the space between the accommodation units  901  and  902 , the maintenance space is formed adjacent to the back door  400  outside the loading area  40  (the housing  30 ). When the replacement member such as the boat  44  is transferred into the loading area  40  (see the black arrow), the replacement member passes through the maintenance space between the accommodation units  901  and  902 . 
     Here, in the thermal processing apparatus  10 , cameras  80   c ,  80   d , and  80   e  are provided to capture an image of the replacement member (the boat  44 ) inside the maintenance space. For example, the camera  80   c  is provided on the wall surface of the accommodation unit  901 , and captures an image of the inside of the maintenance space. The camera  80   d  is provided on the wall surface of the accommodation unit  902 , and captures an image of the inside of the maintenance space. The camera  80   e  is provided on the wall surface of the housing  30 , and captures an image of the inside of the maintenance space. The white arrows indicate an example of the directions in which the cameras  80   c ,  80   d , and  80   e  capture images. 
     The control device  100  determines the shape of the member based on the images captured by the cameras  80   c ,  80   d , and  80   e , and determines whether the member of the captured images is a correct replacement member. Then, the control device  100  outputs the determination result to, for example, the output device  502 , so as to notify the operator with the determination result. Thus, it may be determined whether the member of the captured images is a correct member, before the operator transfers the replacement member into the loading area  40  and installs the replacement member therein. As a result, the operator&#39;s retry for the replacement work may be prevented so that the work efficiency is improved. 
     At least one of the cameras  80   c ,  80   d , and  80   e  may be made drawable. In this case, the operator draws the camera, and captures identification information such as numbers written on the replacement member with the drawn camera. Based on the identification information captured by the camera, the control device  100  determines whether the member of the captured image is a correct replacement member. Then, the control device  100  may output the determination result to, for example, the output device  502 , so as to notify the operator with the determination result. 
     Since the cameras  80   c ,  80   d , and  80   e  are provided outside the housing  30 , the input of heat from the boat  44  heated inside the thermal processing furnace  60  may be prevented. 
     According to an aspect of the present disclosure, it is possible to provide a substrate processing apparatus and an image capturing method which capture an image of a transfer target. 
     From the foregoing, it will be appreciated that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the following claims.