Patent Publication Number: US-2021187659-A1

Title: Laser processing apparatus, laser processing method, and method for manufacturing semiconductor device

Description:
TECHNICAL FIELD 
     The present invention relates to a laser processing apparatus, a laser processing method, and a method for manufacturing a semiconductor device. For example, the present invention relates to a laser processing apparatus, a laser processing method, and a method for manufacturing a semiconductor device, in which the semiconductor device is manufactured by irradiating it with laser light. 
     BACKGROUND ART 
     Patent Literature 1 discloses a laser processing apparatus for crystalizing an amorphous film formed over a silicon substrate, a glass substrate, or the like by irradiating it with laser light. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: International Patent Publication No. WO2015/174347 
     SUMMARY OF INVENTION 
     Technical Problem 
     As the size of displays of television sets and the like has been increasing, the size of glass substrates and the like used for the manufacturing of panels has been increasing. Further, there is a trend toward increasing the size of glass substrates and the like in order to increase the number of panels that can be obtained from one glass substrate or the like. As the size of objects to be processed, such as glass substrates, has been increasing, various problems have arisen in laser processing processes for such objects to be processed performed in the panel manufacturing process. 
     Other problems to be solved and novel features will become apparent from descriptions in this specification and accompanying drawings. 
     Solution to Problem 
     A laser processing apparatus according to an embodiment includes a control unit configured to instruct a loading/unloading apparatus about a placement position of an object to be processed, the loading/unloading apparatus being configured to unload the object to be processed. 
     A laser processing method according to an embodiment includes the steps of: instructing a loading/unloading apparatus about a placement position of an object to be processed, the loading/unloading apparatus being configured to unload the object to be processed; and performing laser processing for the object to be processed. 
     A method for manufacturing a semiconductor device according to an embodiment includes the steps of: instructing a loading/unloading apparatus about a placement position of a substrate, the loading/unloading apparatus being configured to unload the substrate; and performing laser processing for the substrate. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a plan view showing an example of a laser processing apparatus according to an embodiment; 
         FIG. 2  is a perspective view showing an example of a laser processing apparatus according to an embodiment; 
         FIG. 3  is a plan view showing an example of pusher pins of a laser processing apparatus according to an embodiment; 
         FIG. 4  is a cross-sectional view showing an example of pusher pins of a laser processing apparatus according to an embodiment; 
         FIG. 5  is a cross-sectional view showing an example of an optical path of laser light of a laser processing apparatus according to an embodiment; 
         FIG. 6  is a block diagram showing an example of a communication system of a laser processing apparatus according to an embodiment; 
         FIG. 7  is a plan view showing an example of an object to be processed in a laser processing apparatus according to an embodiment, and showing a case where a 60-inch panel is formed over a G10 substrate; 
         FIG. 8  is a plan view showing an example of an object to be processed in a laser processing apparatus according to an embodiment, and showing a case where a 70-inch panel is formed over a G10 substrate; 
         FIG. 9  is a plan view showing an example of an object to be processed in a laser processing apparatus according to an embodiment, and showing a case where an 80-inch panel is formed over a G10 substrate; 
         FIG. 10  is a plan view showing an example of an object to be processed in a laser processing apparatus according to an embodiment, and showing a case where a 65-inch panel is formed over a G10.5 substrate; 
         FIG. 11  is a plan view showing an example of an object to be processed in a laser processing apparatus according to an embodiment, and showing a case where a 75-inch panel is formed over a G10.5 substrate; 
         FIG. 12  is a plan view showing an example of an object to be processed in a laser processing apparatus according to an embodiment, and showing a case where an 85-inch panel is formed over a G10.5 substrate; 
         FIG. 13  is a flowchart showing an example of a laser irradiation method using a laser processing apparatus according to an embodiment; 
         FIG. 14  shows an example of an operation performed by a control unit of a laser processing apparatus and a loading/unloading apparatus according to an embodiment; 
         FIG. 15  shows an example of an operation performed by a control unit of a laser processing apparatus and a loading/unloading apparatus according to an embodiment; 
         FIG. 16  is a plan view showing an example of a laser processing apparatus according to a comparative example; 
         FIG. 17  is a plan view showing an example of holding means according to a first modified example of an embodiment; 
         FIG. 18  is a plan view showing an example of a stage according to a second modified example of an embodiment; 
         FIG. 19  is a cross-sectional view showing an example of a stage according to the second modified example of the embodiment; 
         FIG. 20  is a cross-sectional view showing an example a method for manufacturing a semiconductor device; and 
         FIG. 21  is a cross-sectional view for explaining an outline of an organic EL (Electro Luminescence) display, and shows a pixel circuit of the organic EL display in a simplified manner. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiment 
     A laser processing apparatus according to an embodiment will be described. Firstly, a configuration of the laser processing apparatus will be described. Next, a loading/unloading apparatus that loads/unloads an object to be processed onto/from a laser processing apparatus and the object to be processed in the laser processing apparatus will be described. After that, a laser processing method using the laser processing apparatus will be described. 
     &lt;Configuration of Laser Processing Apparatus&gt; 
       FIG. 1  is a plan view showing an example of a laser processing apparatus according to an embodiment.  FIG. 2  is a perspective view showing the example of the laser processing apparatus according to the embodiment. As shown in  FIGS. 1 and 2 , the laser processing apparatus  1  includes a processing chamber  18 , a stage  10 , and a laser irradiation unit  20 . 
     The processing chamber  18  is, for example, a rectangular parallelepiped housing with an internal space formed therein. Laser processing is performed for an object to be processed  40  inside the processing chamber  18 . As described above, the processing chamber  18  is provided to perform the laser processing for the object to be processed  40  therein. The processing chamber  18  includes a loading gate  17   a  through which the object to be processed  40  is carried in and an unloading gate  17   b  through which the object to be processed  40  is carried out. 
     The stage  10  has, for example, a rectangular parallelepiped shape and has a top surface  11  extending in one direction. The stage  10  is disposed inside the processing chamber  18 . The stage  10  is provided for conveying the object to be processed  40 . 
     Note that for the sake of explanation of the laser processing apparatus  1 , an XYZ-orthogonal coordinate system is introduced. One direction in a plane parallel to the top surface  11  is defined as an X-axis direction. In the plane parallel to the top surface  11 , another direction orthogonal to the X-direction is defined as a Y-axis direction. A direction orthogonal to the top surface  11  is defined as a Z-axis direction. Regarding the Z-axis direction, for example, an upward direction is defined as a Z-axis positive direction and a downward direction is defined as a Z-axis negative direction. 
     The stage  10  is used for laser processing in which the object to be processed  40  is irradiated with laser light. In the stage  10 , the object to be processed  40  is moved from a vicinity  12  of one end of the top surface  11  to a vicinity  13  of the other end thereof along the X-axis direction over the top surface  11 . For example, a vicinity of the end of the top surface  11  on the X-axis direction negative side in the X-axis direction is referred to as the vicinity  12  of one end. A vicinity of the end of the top surface  11  on the X-axis direction positive side in the X-axis direction is referred to as the vicinity  13  of the other end. 
     To move the object to be processed  40  from the vicinity  12  of one end of the top surface  11  to the vicinity  13  of the other end thereof is referred to as conveyance. The loading gate  17   a  of the processing chamber  18  is disposed in the vicinity  12  of one end and the unloading gate  17   b  is disposed in the vicinity  13  of the other end. A direction from the loading gate  17   a  toward the unloading gate  17   b  over the stage  10  is referred to as a first direction. For example, the first direction is the X-axis positive direction. The object to be processed  40  is conveyed only in the first direction from the loading gate  17   a  to the unloading gate  17   b  over the stage  10 . Over the stage  10 , the object to be processed  40  may be conveyed while being levitated over the top surface  11 . For example, a plurality of minute holes are formed in the top surface  11 . Further, air is ejected upward from the minute holes of the top surface  11 . The object to be processed  40  disposed over the top surface  11  is conveyed while being levitated over the stage  10  by the air ejected from the holes. 
     The object to be processed  40  is moved in the X-axis positive direction in the X-axis direction over the top surface  11  of the stage  10 . The stage  10  may not include a mechanism for moving the object to be processed  40  in the X-axis negative direction in the X-axis direction and in the Y-axis positive and negative directions in the Y-axis direction. Note that the stage  10  may include an alignment apparatus for finely adjusting the position of the object to be processed  40  disposed over the top surface  11 . 
     A first position  11   a  and a second position  11   b  are set in the vicinity  12  of one end in the X-axis direction over the top surface  11  as placement positions of the object to be processed  40 . The second position  11   b  is displaced from the first position  11   a  by a predetermined length in the Y-axis direction. For example, when the X-axis positive direction is defined as the first direction, the Y-axis direction is referred to as a second direction intersecting the first direction. For example, the first position  11   a  is displaced from the second position  11   b  in the second direction (toward the Y-axis direction positive side). A part of the first position  11   a  overlaps a part of the second position  11   b  over the top surface  11  of the stage  10 . Note that placement positions for the object to be processed  40  other than the first and second positions  11   a  and  11   b  may be set in the vicinity  12  of one end. 
     A third position  11   c  and a fourth position  11   d  are set in the vicinity  13  of the other end in the X-axis direction over the top surface  11 . The fourth position  11   d  is displaced from the third position  11   c  by a predetermined length in the Y-axis direction. For example, the third position  11   c  is displaced from the fourth position  11   d  toward the Y-axis direction positive side. A part of the third position  11   c  overlaps a part of the fourth position  11   d  over the top surface  11  of the stage  10 . Note that placement positions for the object to be processed  40  other than the third and fourth positions  11   c  and  11   d  may be set in the vicinity  13  of the other end. 
     The third position  11   c  is a position to which the object to be processed  40  is moved from the first position  11   a  along the X-axis direction. The fourth position  11   d  is a position to which the object to be processed  40  is moved from the second position  11   b  along the X-axis direction. 
       FIG. 3  is a plan view showing an example of pusher pins of a laser processing apparatus according to an embodiment.  FIG. 4  is a cross-sectional view showing the example of the pusher pins of the laser processing apparatus according to the embodiment.  FIG. 3  shows a block diagram in addition to the plan view. As shown in  FIGS. 3 and 4 , the stage  10  may include pusher pins  14 . Each pusher pin  14  is a pin-like member extending in the Z-axis direction. The tip of the pusher pin  14  rises and falls relative to the top surface  11  of the stage  10 . 
     The plurality of pusher pins  14  protrude from the top surface  11  of the stage  10 . An object to be processed  40  is held by the plurality of pusher pins  14 . The pusher pins  14  function as holding means for the object to be processed  40 . Specifically, the plurality of pusher pins  14  function as a loading holding part which is used when a loading/unloading apparatus  30  loads an object to be processed  40 , and as an unloading holding part which is used when the loading/unloading apparatus  30  unloads the object to be processed  40 . The pusher pins  14  are provided in at least one of the first and second positions  11   a  and  11   b  over the top surface  11  of the stage  10 . For example, the pusher pins  14  protrude from the top surface  11  in the first and second positions  11   a  and  11   b . In this way, the pusher pins  14  lifts the object to be processed  40 . Note that the loading holding part and the unloading holding part provided in the stage  10  are not limited to the pusher pins  14 . That is, they may be bars or a plurality of grooves as described later. 
     When the object to be processed  40  is moved along the X-axis direction, the pusher pins  14  are accommodated below the top surface  11 . The movement of the pusher pins  14  in the first position  11   a  is controlled by a first pusher pin driver  14   a . The movement of the pusher pins  14  in the second position  11   b  is controlled by a second pusher pin driver  14   b . The first and second pusher pin drivers  14   a  and  14   b  are controlled by a motion controller  15 . The plurality of pusher pins  14  located in the first position  11   a  and the plurality of pusher pins  14  located in the second position  11   b  may be simultaneously raised and lowered. Alternatively, only those located in the first position  11   a  or those located in the second position  11   b  may be raised and lowered. 
     As shown in  FIG. 2 , the stage  10  may include a grasping part  16  for grasping the object to be processed  40 . The grasping part  16  is disposed in the top surface  11  of the stage  10 . The grasping part  16  is, for example, a vacuum chuck. The grasping part  16  is moved along a groove extending in the X-axis direction. The grasping part  16  sucks the bottom surface of the object to be processed  40 . Then, the grasping part  16  conveys the object to be processed  40  in the X-axis direction. Note that the means for conveying the object to be processed  40  in the X-axis direction is not limited to the grasping part  16 . 
     After the pusher pins  14  located in the first and second positions  11   a  and  11   b  are accommodated in the stage  10 , the grasping part  16  grasps the object to be processed  40 . In the first and second positions  11   a  and  11   b , the pusher pins  14  may be accommodated in the stage  10  in such a manner that the closer they are located to the grasping part  16 , the earlier they are accommodated in the stage  10 . 
     If the pusher pins  14  are accommodated in the stage  10  in such a manner that the closer they are located to the grasping part  16 , the later they are accommodated in the stage  10 , there is a possibility that a peripheral part of the bottom surface of the object to be processed  40  comes into contact with the top surface  11  of the stage  10  earlier than the central part of the bottom surface does. As a result, some air is trapped between the central part of the bottom surface of the object to be processed  40  and the top surface  11  of the stage  10 , thus forming a gap therebetween. In such a case, there is a possibility that the grasping part  16  cannot grasp the object to be processed  40 . 
     In this embodiment, the pusher pins  14  are accommodated in the stage  10  in such a manner that the closer they are located to the grasping part  16 , the earlier they are accommodated in the stage  10 . Therefore, the formation of a gap between the object to be processed  40  and the top surface  11  is prevented. As a result, the grasping part  16  can grasp the object to be processed  40 . 
     The stage  10  may be disposed inside the processing chamber  18 , which includes the loading gate  17   a  and the unloading gate  17   b . The unloading gate  17   b  is different from the loading gate  17   a.    
       FIG. 5  is a cross-sectional view showing an example of an optical path of laser light in a laser processing apparatus  1  according to an embodiment. As shown in  FIG. 5 , a laser irradiation unit  20  applies laser light L 1  to an object to be processed  40 . For example, the laser irradiation unit  20  applies the laser light L 1  to an object to be processed  40  moving over the top surface  11  of the stage  10 . The laser irradiation unit  20  includes a laser oscillator (not shown) and an optical member(s) for guiding the laser light L 1  emitted from the laser oscillator onto the stage  10 . The laser irradiation unit  20  is disposed in a position where it can receive the laser light L 1  emitted from the laser oscillator. 
     The laser light L 1  travels, for example, in the X-axis negative direction and enters the laser irradiation unit  20 . Note that if necessary, an optical element(s) such as an attenuator for adjusting the energy density of the laser light L 1  may be disposed between the light source and the laser irradiation unit  20  in the optical path of the laser light L 1 . 
     The laser irradiation unit  20  includes an optical system housing  28   a  constituting an exterior thereof, a mirror  28   b , an optical element such as a lens, and an enclosed part  28   c . The laser irradiation unit  20  adjusts the direction in which the laser light L 1  emitted from the light source is applied, the amount of the laser light, and the like. The enclosed part  28   c  is disposed below the optical system housing  28   a . After being adjusted by the laser irradiation unit  20 , the laser light L 1  is made to enter the processing part  18  through the enclosed part  28   c  and a sealing window  28   h.    
     The laser light L 1  is shaped into a line beam shape in the laser irradiation unit  20 . That is, the laser light L 1  is shaped into a long and narrow linear shape extending in one direction. For example, a cross section of the laser light L 1 , which has been reflected on the mirror  28   b , perpendicular to the optical axis thereof has a linear shape extending in the Y-axis direction. The laser light L 1  has, for example, a shape of a line beam  21  extending in the Y-axis direction over the top surface of the object to be processed  40 . The length of the line beam  21  in the Y-axis direction is, for example, about 1,500 [mm] at the maximum. The length of the line beam  21  is adjusted, for example, by using a slit. The processing chamber  18  includes a gas box  28   d  and the stage  10 . 
     A certain gas  28   f , which is, for example, an inert gas such as nitrogen, is supplied to the gas box  28   d  through a gas inlet  28   e . The gas  28   f  supplied to the gas box  28   d  is charged into inside the gas box  28   d  and then discharged from an irradiation window  28   g . In the processing chamber  18 , a laser annealing process in which the object to be processed  40  placed over the stage  10  is irradiated with the laser light L 1  and its amorphous film is thereby crystalized is performed. 
     The laser processing apparatus  1  may include a control unit  50 . As will be described later, the loading/unloading apparatus  30  may also include a loading/unloading control unit  31  that controls loading/unloading of the object to be processed  40 . The control unit  50  instructs the loading/unloading apparatus  30  to place the object to be processed  40  in the first position  11   a  in the vicinity  12  of one end of the top surface  11  of the stage  10  inside the processing chamber  18 , or in the second position  11   b  in the vicinity  12  of the one end thereof. Further, the control unit  50  may select the first position  11   a  or the second position  11   b  as the placement position of the object to be processed  40 . The control unit  50  instructs the loading/unloading apparatus  30  about the selected placement position. As described above, the control unit  50  instructs the loading/unloading unit  30 , which loads/unloads the object to be processed  40  into/from the processing chamber  18 , about the placement position of the object to be processed  40  over the stage  10 . A signal by which the control unit  50  indicates the placement position is referred to as a position control signal. 
     When the object to be processed  40  is placed over the stage  10 , the control unit  50  makes the loading/unloading apparatus  30  carry in the object to be processed  40  through the loading gate  17   a  and place it over the top surface  11 . When the object to be processed  40  is unloaded from the stage  10 , the control part  50  makes the loading/unloading apparatus  30  carry out the object to be processed  40  through the unloading gate  17   b.    
       FIG. 6  is a block diagram showing an example of a communication system of the laser processing apparatus  1  according to the embodiment. As shown in  FIG. 6 , a main control unit  51 , a sub control unit  52 , a laser irradiation unit controller  22 , a loading/unloading apparatus  30 , a door valve  23 , a levitating unit controller  24 , a motion controller  15 , an XYθ-stage  25 , and pusher pins  14  are connected to the communication system of the laser processing apparatus  1 . 
     The main control unit  51  is, for example, a PC (Personal Computer). The sub control unit  52  is, for example, a ladder controller. The main control unit  51  and the sub control unit  52  may be integrally formed. The main control unit  51  and the sub control unit  52  are collectively referred to as a control unit  50 . Further, each of the main control unit  51  and the sub control unit  52  is also referred to as a control unit  50 . 
     The laser irradiation unit controller  22  controls the oscillation, the stop, the output, the wavelength, and the like of the laser light. The control unit  50  controls the oscillation, the stop, the output, the wavelength, and the like of the laser light by controlling the laser irradiation unit controller  22 . 
     The control unit  50  controls the loading/unloading of an object to be processed  40  onto/from the stage  10 . The control unit  50  controls the opening/closing of the loading gate  17   a  and the unloading gate  17   b  by controlling the door valve  23  of the processing chamber  18  with which the stage  10  is enclosed. 
     The levitating unit controller  24  controls the ejection of air from the holes formed in the top surface  11  of the stage  10 . The control unit  50  controls the levitation of the object to be processed  40  over the top surface  11  by controlling the levitating unit controller  24 . 
     The motion controller  15  controls the position and the movement of the object to be processed  40  over the top surface  11  of the stage  10 . The motion controller  15  moves the object to be processed  40  in the X-axis positive direction over the top surface  11  of the stage  10 . For example, the motion controller  15  moves the object to be processed  40  in the X-axis positive direction by controlling the grasping part  16  that grasps the object to be processed  40 . Further, the motion controller  15  finely adjusts the position of the object to be processed  40 , for example, by controlling the XYθ-stage  25 . The motion controller  15  controls the rise and fall of the pusher pins  14  through the pusher pin drivers  14   a  and  14   b.    
     &lt;Loading/Unloading Apparatus&gt; 
     Next, the loading/unloading apparatus  30  that loads/unloads an object to be processed  40  onto/from the laser processing apparatus  1  will be described. 
     The loading/unloading apparatus  30  loads and unloads the object to be processed  40 . The loading/unloading apparatus  30  is, for example, a loading/unloading robot. The loading/unloading robot may be composed of a loading robot and an unloading robot. The loading/unloading apparatus  30  places the object to be processed  40  in the vicinity  12  of one end of the top surface  11  of the stage  10 . Further, the loading/unloading apparatus  30  unloads the object to be processed  40  from the vicinity  13  of the other end of the top surface  11 . Specifically, in response to an instruction from the control unit  50  of the laser processing apparatus  1 , the loading/unloading  30  places the object to be processed  40  in the first position  11   a  or the second position  11   b  in the vicinity  12  of one end of the top surface  11  through the loading gate  17   a . The loading/unloading apparatus  30  places the object to be processed  40  in one of the first and second positions  11   a  and  11   b  selected by the control unit  50  as the placement position of the object to be processed  40 . As described above, the loading/unloading apparatus  30  can place the object to be processed  40  that has been carried in through the loading gate  17   a  at a predetermined position in the second direction intersecting the first direction. The predetermined position is determined according to the position control signal sent from the control unit  50 . 
     The loading/unloading apparatus  30  includes a loading/unloading control unit  31  that controls the loading/unloading of the object to be processed  40 . Further, when the loading/unloading control unit  31  is instructed to place the object to be processed  40  in the first position  11   a  or the second position  11   b  by the control unit  50  of the laser processing apparatus  1 , the loading/unloading control unit  31  may select the first position  11   a  or the second position  11   b  as the placement position of the object to be processed  40 . The loading/unloading control part  31  places the object to be processed  40  in the selected placement position. The control part  50  of the laser processing apparatus  1  controls each of the controllers so that the object to be processed  40  can be placed in the placement position selected by the loading/unloading control unit  31 . 
     When the loading/unloading apparatus  30  unloads the object to be processed  40  from the top surface  11  of the stage  10 , the loading/unloading apparatus  30  unloads the object to be processed  40  from the third position  11   c  in the vicinity  13  of the other end of the top surface  11  or the fourth position  11   d  near the vicinity  13  of the other end thereof. Specifically, the loading/unloading apparatus  30  unloads the object to be processed  40 , which has been placed in the first position  11   a , conveyed in the first direction, and disposed in the third position  11   c . Further, the loading/unloading apparatus  30  unloads the object to be processed  40 , which has been placed in the second position  11   b , conveyed in the first direction, and disposed in the fourth position  11   d . As described above, the position from which the object to be processed  40  is taken out changes according to the position in which the object to be processed  40  is placed by the loading/unloading apparatus  30  when the object to be processed  40  is loaded. That is, the object to be processed  40  placed in the first position  11   a  is unloaded from the third position  11   c , and the object to be processed  40  placed in the second position  11   b  is unloaded from the fourth position  11   c.    
     The loading/unloading apparatus  30  carries in the object to be processed  40  through the loading gate  17   a  and places the object to be processed  40  over the top surface  11 . The loading/unloading apparatus  30  carries out the object to be processed  40  through the unloading gate  17   b . The loading/unloading apparatus  30  may take out an object to be processed  40  that has not been processed yet from a cassette  34 . The loading/unloading apparatus  30  may store an object to be processed  40  that has already been processed into a cassette  34 . 
     &lt;Object to be Processed&gt; 
     Next, the object to be processed  40  which undergoes laser processing performed by the laser processing apparatus  1  will be described. The object to be processed  40  includes, for example, a substrate and a semiconductor film formed over the substrate. The substrate is, for example, a rectangular plate-like member. The object to be processed  40  has a rectangular (or square) planar shape. Specifically, the substrate is a glass substrate and the semiconductor film is an amorphous silicon film. Laser light is applied to the amorphous silicon film, so that the amorphous film is crystalized. In this way, a polycrystalline silicon film is formed. Note that the object to be processed  40  is not limited to the substrate with an amorphous silicon film formed thereover, provided that the laser irradiation process is performed for it. 
       FIGS. 7 to 12  are plan views showing examples of the object to be processed  40  processed by the laser processing apparatus  1  according to an embodiment, and  FIG. 7  shows a case where a 60-inch panel is formed in a G10 substrate.  FIG. 8  shows a case where a 70-inch panel is formed in a G10 substrate.  FIG. 9  shows a case where an 80-inch panel is formed in a G10 substrate.  FIG. 10  shows a case where a 65-inch panel is formed in a G10.5 substrate.  FIG. 11  shows a case where a 75-inch panel is formed in a G10.5 substrate.  FIG. 12  shows a case where an 85-inch panel is formed in a G10.5 substrate. 
     As shown in  FIGS. 7 to 9 , when the object to be processed  40  includes a substrate, the lengths of the sides of the substrate are 3,130 [mm] and 2,880 [mm]. A glass substrate having such side lengths is referred to as a 10th-generation (G10) substrate. As shown in  FIGS. 10 to 12 , the lengths of the sides of the substrate may be 3,370 [mm] and 2,940 [mm]. A glass substrate having such side lengths is referred to as a 10.5th-generation (G10.5) substrate. 
     Further, although not shown in the drawings, the lengths of the sides of the substrate may be 2,500 [mm] and 2,200 [mm]. A glass substrate having such side lengths is referred to as an 8th-generation (G8) substrate. Further, the object to be processed  40  is preferably a glass substrate having an area of 2,160 [mm]×2,460 [mm] or larger. The thickness of the substrate is 0.5 to 0.63 [mm]. 
     As described above, the length of the object to be processed  40 , which is placed over the top surface  11  of the stage  10 , in the Y-axis direction is 2,200 [mm] or longer. Therefore, the length of the object to be processed  40  in the Y-axis direction is longer than the length of the line beam  21  of the laser light. That is, the length of the irradiation area in the Y-axis direction on the object to be processed  40  placed over the top surface  11  of the stage  10  is longer than the length of the line beam  21 . The irradiation area is an area that needs to be irradiated with laser light. 
     When the length of the irradiation area in the Y-axis direction is longer than the length of the line beam  21 , the object to be processed  40  cannot be processed through one conveyance. Therefore, the object to be processed  40  is moved from the vicinity  12  of one end of the top surface  11  of the stage  10  to the vicinity  13  of the other end thereof a plurality of times. 
     As shown in  FIG. 7 , a substrate having a size of 3,130 [mm]×2,880 [mm] placed over the top surface  11  of the stage  10  includes eight (4×2) panels  45  each of which is the so-called 60-inch panel having a size of 764 [mm]×1,341 [mm]. Note that the length or the number in front of “×” indicates the length or the number in the X-axis direction, and the length or the number behind “×” indicates the length or the number in the Y-axis direction. The length of the line beam  21  of the laser light is set to 1,440 [mm]. In this case, the irradiation area on the object to be processed  40  includes a first irradiation part  41  and a second irradiation part  42 . Each of the first and second irradiation parts  41  and  42  is a part that can be irradiated with laser light by one transfer of the object to be processed  40  in the X-axis direction. Each of the irradiation parts extends in the X-axis direction. 
     The first irradiation part  41  is, for example, a part located on the Y-axis direction negative side when the object to be processed  40  is divided into two equal parts in the Y-axis direction. The second irradiation part  42  is a part located on the Y-axis direction positive side when the object to be processed  40  is divided into two equal parts in the Y-axis direction. 
     When the first irradiation part  41  is irradiated with laser light, the object to be processed  40  is placed, for example, in the first position  11   a . Then, the object to be processed  40  is conveyed along the X-axis direction. When the object to be processed  40  is moved over the top surface  11  of the stage  10 , the first irradiation part  41  is irradiated with laser light. In this way, the first irradiation part  41  can be processed by the laser light. 
     Next, when the second irradiation part  42  is irradiated with laser light, the object to be processed  40  is placed in the second position  11   b . Then, the object to be processed  40  is conveyed along the X-axis direction. When the object to be processed  40  is moved over the top surface  11  of the stage  10 , the second irradiation part  42  is irradiated with laser light. In this way, the second irradiation part  42  can be processed by the laser light. 
     As described above, when the object to be processed  40  placed in the first position  11   a  is moved in the X-axis direction, the first irradiation part  41  is irradiated with laser light. When the object to be processed  40  placed in the second position  11   b  is moved in the X-axis direction, the second irradiation part  42  is irradiated with laser light. 
     As shown in  FIG. 8 , a substrate having a size of 3,130 [mm]×2,880 [mm] placed over the top surface  11  includes six (2×3) panels  45  each of which is the so-called 70-inch panel having a size of 1,546 [mm]×888 [mm]. The length of the line beam  21  of the laser light is set to 960 [mm]. In this case, the irradiation area on the object to be processed  40  includes a first irradiation part  41 , a second irradiation part  42 , and a third irradiation part  43 . Each of the first, second and third irradiation parts  41 ,  42  and  43  is a part that can be irradiated with laser light by one transfer of the object to be processed  40  in the X-axis direction. Each of the irradiation parts extends in the X-axis direction. Note that  FIG. 8  shows a state in which the object to be processed  40  is placed in the first position  11   a.    
     The first irradiation part  41  is a part located on the Y-axis direction negative side when the object to be processed  40  is divided into three equal parts in the Y-axis direction. The second irradiation part  42  is a central part when the object to be processed  40  is divided into three equal parts in the Y-axis direction. The third irradiation part  43  is a part located on the Y-axis direction positive side when the object to be processed  40  is divided into three equal parts in the Y-axis direction. Therefore, in the object to be processed  40 , the second irradiation part  42  is located between the first and third irradiation parts  41  and  43 . 
     When the first irradiation part  41  is irradiated with laser light, the object to be processed  40  is placed in the first position  11   a . Then, the object to be processed  40  is conveyed along the X-axis direction. When the object to be processed  40  is moved over the top surface  11  of the stage  10 , the first irradiation part  41  is irradiated with laser light. In this way, the first irradiation part  41  can be processed by the laser light. 
     Next, when the second irradiation part  42  is irradiated with laser light, the object to be processed  40  is placed in the second position  11   b . Then, the object to be processed  40  is conveyed along the X-axis direction. When the object to be processed  40  is moved over the top surface  11  of the stage  10 , the second irradiation part  42  is irradiated with laser light. In this way, the second irradiation part  42  can be processed by the laser light. 
     Next, when the third irradiation part  43  is irradiated with laser light, the object to be processed  40  is first rotated by 180 [° ] in a horizontal plane. For example, the object to be processed  40  is rotated by a rotating apparatus  32  provided outside the stage  10 . Then, the object to be processed  40  is placed in the first position  11   a . After that, the object to be processed  40  is conveyed along the X-axis direction. When the object to be processed  40  is moved over the top surface  11 , the third irradiation part  43  is irradiated with laser light. In this way, the third irradiation part  43  can be irradiated with the laser light. 
     As described above, when the object to be processed  40  placed in the first position  11   a  is moved in the X-axis direction, the first irradiation part  41  or the third irradiation part  43  is irradiated with laser light. When the object to be processed  40  placed in the second position  11   b  is moved in the X-axis direction, the second irradiation part  42  is irradiated with laser light. 
     As shown in  FIG. 9 , a substrate having a size of 2,880 [mm]×3,130 [mm] placed over the top surface  11  includes three (1×3) panels  45  each of which is the so-called 80-inch panel having a size of 1,806 [mm]×1,029 [mm]. The length of the line beam  21  of the laser light is set to 1,043 [mm]. In this case, the irradiation area on the object to be processed  40  includes a first irradiation part  41 , a second irradiation part  42 , and a third irradiation part  43 . Each of the first, second and third irradiation parts  41 ,  42  and  43  is a part that can be irradiated by one transfer of the object to be processed  40  in the X-axis direction. Each of the irradiation parts extends in the X-axis direction. Note that  FIG. 9  shows a state in which the object to be processed  40  is placed in the first position  11   a  over the top surface  11  of the stage  10 . 
     The first irradiation part  41  is a part located on the Y-axis direction negative side when the object to be processed  40  is divided into three equal parts in the Y-axis direction. The second irradiation part  42  is a central part when the object to be processed  40  is divided into three equal parts in the Y-axis direction. The third irradiation part  43  is a part located on the Y-axis direction positive side when the object to be processed  40  is divided into three equal parts in the Y-axis direction. Therefore, in the object to be processed  40 , the second irradiation part  42  is located between the first and third irradiation parts  41  and  43 . 
     Even in the case of  FIG. 9 , when the object to be processed  40  placed in the first position  11   a  is moved in the X-axis direction, the first irradiation part  41  or the third irradiation part  43  is irradiated with laser light. When the object to be processed  40  placed in the second position  11   b  is moved in the X-axis direction, the second irradiation part  42  is irradiated with laser light. 
     As shown in  FIG. 10 , a substrate having a size of 3,370 [mm]×2,940 [mm] placed over the top surface  11  of the stage  10  includes eight (4×2) panels  45  each of which is the so-called 65-inch panel having a size of 820 [mm]×1,445 [mm]. The length of the line beam  21  of the laser light is set to 1,470 [mm]. In this case, the irradiation area on the object to be processed  40  includes a first irradiation part  41  and a second irradiation part  42 . The relation between the first and second irradiation parts  41  and  42 , and the relation between the first and second positions  11   a  and  11   b  are similar to those of the substrate shown in  FIG. 7 . 
     As shown in  FIG. 11 , a substrate having a size of 3,370 [mm]×2,940 [mm] placed over the top surface  11  of the stage  10  includes six (2×3) panels  45  each of which is the so-called 75-inch panel having a size of 1,666 [mm]×944 [mm]. The length of the line beam  21  of the laser light is set to 980 [mm]. In this case, the irradiation area on the object to be processed  40  includes a first irradiation part  41 , a second irradiation part  42 , and a third irradiation part  43 . The relation among the first, second and third irradiation parts  41 ,  42  and  43 , and the relation between the first and second positions  11   a  and  11   b  are similar to those of the substrate shown in  FIG. 8 . 
     As shown in  FIG. 12 , a substrate having a size of 2,940 [mm]×3,370 [mm] placed over the top surface  11  of the stage  10  includes three (1×3) panels  45  each of which is the so-called 85-inch panel having a size of 1,892 [mm]×1,073 [mm]. The length of the line beam  21  of the laser light is set to 1,123 [mm]. In this case, the irradiation area on the object to be processed  40  includes a first irradiation part  41 , a second irradiation part  42 , and a third irradiation part  43 . The relation among the first, second and third irradiation parts  41 ,  42  and  43 , and the relation between the first and second positions  11   a  and  11   b  are similar to those of the substrate shown in  FIG. 9 . 
     Note that cases in which the irradiation area on the object to be processed  40  includes two or three irradiation parts have been described. However, the irradiation area on the object to be processed  40  may include four or more irradiation parts. 
     &lt;Laser Processing Method&gt; 
     Next, a laser irradiation method will be described for explaining operations performed by the laser processing apparatus  1 .  FIG. 13  is a flowchart showing an example of a laser irradiation method using a laser processing apparatus according to an embodiment. As shown in a step S 11  in  FIG. 13 , firstly, an object to be processed  40  is loaded onto the stage  10  and placed in the placement position. The placement position of the object to be processed  40  is selected by the control unit  50  or the loading/unloading control unit  31 . 
       FIG. 14  shows an example of operations performed by the laser processing apparatus  1  and the loading/unloading apparatus  30  according to an embodiment, and shows a case where the control unit  50  of the laser processing apparatus  1  selects the placement position of the object to be processed  40  and instructs the loading/unloading apparatus  30  about the selected placement position. 
     As shown in  FIG. 14 , the control unit  50  requests the loading/unloading apparatus  30  to load the object to be processed  40 . When doing so, the control unit  50  selects the first position  11   a  or the second position  11   b  as the placement position of the object to be processed  40 . For example, the control unit  50  first selects the first position  11   a  as the placement position. Then, the control unit  50  instructs the loading/unloading apparatus  30  to place the object to be processed  40  in the selected first position  11   a . As described above, the control unit  50  transmits a first position control signal for controlling the placement position of the object to be processed  40  over the stage  10  to the loading/unloading apparatus  30  for the object to be processed  40  (step a). 
     The loading/unloading apparatus  30  inquires of the control unit  50  as to whether the object to be processed  40  can be loaded. In response to this inquiry, the motion controller  15  of the laser processing apparatus  1  raises the pusher pins  14  located in the first position  11   a  which has been selected as the placement position. Further, the control unit  50  opens the door valve  23  of the loading gate  17   a . Then, the control unit  50  notifies the loading/unloading apparatus  30  that the object to be processed  40  can be loaded. 
     In response to this notification, the loading/unloading apparatus  30  places the object to be processed  40  in the first position  11   a  over the top surface  11  of the stage  10  through the loading gate  17   a . That is, the object to be processed  40  is placed, by the loading/unloading apparatus  30 , in the first position over the stage  10  determined by the first position control signal (step b). 
     The loading/unloading apparatus  30  notifies the control unit  50  that the loading of the object to be processed  40  has been completed. The control unit  50  closes the door valve  23  of the loading gate  17   a . The motion controller  15  lowers the pusher pins  14  located in the first position  11   a . Then, the process proceeds to the next process, i.e., proceeds to the processing for the object to be processed  40  along the placement position. 
     As described above, firstly, the object to be processed  40  is placed in the first position  11   a  in the vicinity  12  of one end of the stage  10 . In the laser processing method according to this embodiment, the control unit  50  of the laser processing apparatus  1  is used. Then, firstly, the control unit  50  is made to select the first position  11   a  as the placement position of the object to be processed  40 . The control unit  50  is made to instruct the loading/unloading apparatus  30  about the selected placement position. Further, the control unit  50  is made to instruct the loading/unloading apparatus  30  to place the object to be processed  40  in the first position  11   a.    
       FIG. 15  shows an example of operations performed by the laser processing apparatus  1  and the loading/unloading apparatus  30  according to an embodiment, and shows a case where the loading/unloading control unit  31  of the loading/unloading apparatus  30  selects the placement position of the object to be processed  40  and instructs the laser processing apparatus  1  about the selected placement position. 
     As shown in  FIG. 15 , the control unit  50  of the laser processing apparatus  1  requests the loading/unloading apparatus  30  to load the object to be processed  40 . The loading/unloading control unit  31  of the loading/unloading apparatus  30  inquires of the laser processing apparatus  1  as to whether the object to be processed  40  can be loaded. Further, the loading/unloading control unit  31  selects the first position  11   a  or the second position  11   b  as the placement position of the object to be processed  40 . For example, the loading/unloading control unit  31  first selects the first position  11   a  as the placement position. Then, the loading/unloading control unit  31  instructs the laser processing apparatus  1  so that the object to be processed  40  can be placed in the selected first position  11   a . As described above, the loading/unloading control unit  31  of the loading/unloading apparatus  30  may select the placement position and instruct the laser processing apparatus  1  about the selected placement position. 
     In response to this instruction, the motion controller  15  of the laser processing apparatus  1  raises the pusher pins  14  located in the placement position. Further, the motion controller  15  opens the door valve  23  of the loading gate  17   a . Then, the laser processing apparatus  1  notifies the loading/unloading control unit  31  of the loading/unloading apparatus  30  that the object to be processed  40  can be loaded. 
     The loading/unloading apparatus  30  places the object to be processed  40  in the placement position over the top surface  11  through the loading gate  17   a . The loading/unloading apparatus  30  notifies the laser processing apparatus  1  that the loading of the object to be processed  40  has been completed. The laser processing apparatus  1  closes the door valve  23  of the loading gate  17   a . The motion controller  15  lowers the pusher pins  14  located in the placement position. Then, the process proceeds to the next process, i.e., proceeds to the processing for the object to be processed  40  along the placement position. 
     Next, as shown in a step S 12  in  FIG. 13 , the object to be processed  40  is moved in the X-axis direction over the top surface  11  of the stage  10 . Then, the object to be processed  40  is conveyed to the laser light irradiation position over the stage  10  (step c). For example, the object to be processed  40  placed in the first position  11   a  is moved from the vicinity  12  of one end of the top surface  11  to the vicinity  13  of the other end thereof along the X-axis direction. In this process, the object to be processed  40  is moved only in the first direction. The motion controller  15  controls the grasping part  16  and thereby makes the grasping part  16  grasp the object to be processed  40  and move it in the X-axis direction. When doing so, the object to be processed  40  may be levitated from the top surface  11  by the levitating unit controller  24 . 
     Next, as shown in a step S 13  in  FIG. 13 , the object to be processed  40  is irradiated with laser light. Specifically, the control unit  50  applies laser light to the object to be processed  40 , which is moving over the top surface  11  of the stage  10 , by controlling the laser irradiation unit controller  22  (step d). 
     Next, as shown in a step S 14  in  FIG. 13 , the object to be processed  40  is unloaded by the loading/unloading apparatus  30  (step e). Specifically, the control unit  50  unloads the object to be processed  40  from the vicinity  13  of the other end of the top surface  11  of the stage  10  by controlling the loading/unloading apparatus  30 . 
     Next, as shown in a step S 15  in  FIG. 13 , the control unit  50  determines whether or not all the irradiation areas have been irradiated with laser light. Whether all the irradiation areas have been irradiated with laser light means, in the case where the irradiation areas include the first, second and third irradiation parts  41 ,  42  and  43 , whether all of the first to third irradiation parts are irradiated with laser light. When all the irradiation areas have not been irradiated with laser light (in the case of No), for example, when the first irradiation part  41  has already been irradiated with laser light but the second irradiation part  42  has not irradiated with laser light yet, the process returns to the step S 11 , in which the object to be processed  40  is loaded onto the stage  10  and is placed in the second position  11   b . If necessary, the object to be processed  40  is rotated by the rotating apparatus  32  and then placed over the stage  10 . 
     The placement position of the object to be processed  40  is selected, for example, by the control unit  50 . The control unit  50  selects the second position  11   b  as the placement position of the object to be processed  40 . The control unit  50  instructs the loading/unloading apparatus  30  about the selected placement position. That is, the control unit  50  transmits a second position control signal to the loading/unloading apparatus  30  (step f). Further, the control unit  50  instructs the loading/unloading apparatus  30  to place the object to be processed  40  in the second position  11   b . In response to this instruction, the object to be processed  40  is placed in the second position different from the first position over the stage  10 , which is determined by the second position control signal, by the loading/unloading apparatus  30  (step g). 
     Then, a step S 12  (step h), a step S 13  (step i), and a step S 14  (step j) are successively performed. Note that the direction connecting the first position and the second position intersects the direction in which the object to be processed  40  is conveyed in the steps (c) and (h). Note that similarly to the step (c), the object to be processed  40  moves only in the first direction in the step (h). 
     On the other hand, when it is determined that all the irradiation areas have been irradiated in the step S 15  (in the case of Yes), the laser irradiation process is finished. In this way, the laser processing can be performed for the object to be processed  40 . 
     Next, effects of this embodiment will be described. 
     In the laser processing apparatus  1  according to this embodiment, even when the length of the object to be processed  40  is longer than that of the line beam  21  of the laser light, the object to be processed  40  is moved from the vicinity  12  of one end of the top surface  11  of the stage  10  to the vicinity  13  of the other end thereof only in one direction. Therefore, it is possible to prevent the area of the stage  10  from being increased. 
     The loading/unloading apparatus  30  places the object to be processed  40  in the first position  11   a  or the second position  11   b  in the vicinity  12  of one end. Therefore, the laser processing apparatus  1  does not require a moving mechanism for widely moving the object to be processed  40  in the Y-axis direction. As a result, it is possible to simplify the mechanism of the laser processing apparatus  1  and thereby prevent the size of the laser processing apparatus  1  from being increased. However, the laser processing apparatus  1  may be equipped with a mechanism for finely moving the object to be processed  40  in the Y-axis direction without making the mechanism of the laser processing apparatus  1  considerably complicated. 
       FIG. 16  is a plan view showing an example of a laser processing apparatus according to a comparative example. As shown in  FIG. 16 , a laser processing apparatus  100  according to the comparative example moves an object to be processed  40  in the X-axis direction and in the Y-axis direction over a top surface  11  of a stage  10  when the length of the object to be processed  40  is longer than that of a line beam  21  of laser light. Therefore, the area of the stage  10  is increased. 
     Further, the laser processing apparatus  100  according to the comparative example needs to have a moving mechanism for moving the object to be processed  40  in the Y-axis direction and a rotating mechanism for rotating the object to be processed  40  in a horizontal plane. Therefore, the mechanism of the laser processing apparatus  100  becomes complicated and its size is increased. 
     Further, in the laser processing apparatus  100  according to the comparative example, until the laser processing for one object to be processed  40  is completed, the next object to be processed  40  cannot be placed over the stage  10 . Therefore, it is impossible to improve the cycle time and hence impossible to improve the throughput. Further, wasteful shots in which emitted laser light is not used for the actual processing increase and hence the production cost increases. If the emission of the laser light is stopped in order to reduce the wasteful shots, the stability of the laser light deteriorates. 
     In contrast to this, in the laser processing apparatus  1  according to this embodiment, it is possible to successively convey a plurality of objects to be processed  40  in the X-axis direction over the stage  10 . Therefore, it is possible to improve the cycle time and hence to improve the throughput. Further, since a plurality of objects  40  to be processed can be conveyed in the X-axis direction without interruption, wasteful shots can be reduced and hence the production cost can be reduced. Further, since it is possible to keep the laser light emitting state, the stability of the laser light is improved. 
     In the laser processing apparatus  1  according to this embodiment, a part of the first position  11   a  overlaps a part of the second position  11   b  over the top surface  11 . Therefore, it is possible to prevent the area of the stage  10  from being increased. In the case of using a levitating unit for levitating an object to be processed  40 , it is possible to reduce the consumption of gas ejected from the top surface  11  of the stage  10 . Note that an inert gas such as air or nitrogen is used as the gas ejected from the top surface  11 . 
     Since it is possible to increase the length of a substrate placed over the top surface  11  of the stage  10  to 2,880 [mm] or longer, the laser processing apparatus  1  can be used for glass substrates for next-generation panels. Even when a substrate whose length is three times or longer of the length of the line beam  21  of laser light is irradiated with the laser light, it is possible to place, among the first to third irradiation parts, the first and third irradiation parts  41  and  43  in the first position  11   a  and thereby to irradiate them with the laser light. Therefore, it is possible to make the length of the top surface  11  of the stage  10  in the Y-axis direction shorter than twice the length of the object to be processed  40  in the Y-axis direction. 
     Modified Example 1 
     Next, a modified example 1 of the above-described embodiment will be described. In this modified example, bars are provided in place of the pusher pins  14  as the holding means for the object to be processed  40 . 
       FIG. 17  is a plan view showing an example of holding means according to the modified example 1 of the embodiment. As shown in  FIG. 17 , in this modified example, bars  26  are provided in the top surface  11  of the stage  10 . The bars  26  extend in the Y-axis direction. A plurality of bars  26  may be provided separately in each of the first and second positions  11   a  and  11   b . Alternatively, bars  26  may be provided so as to extend from the first position  11   a  to the second position  11   b.    
     The bars  26  are controlled by the motion controller  15  through a driver(s). The bars  26  are raised from the top surface  11  of the stage  10  when an object to be processed  40  is held by them. The bars  26  are accommodated in the stage  10  when the object to be processed  40  is moved in the X-axis direction. The bars  26  may be accommodated in the stage  10  in such a manner that the closer they are located to the grasping part  16 , the earlier they are accommodated in the stage  10 , so that the grasping part  16  can grasp the object to be processed  40 . Specifically, the bars  26  may be curved so that the closer they are located to the grasping part  16 , the earlier they are accommodated in the stage  10 . 
     According to the laser processing apparatus  1  in accordance with the modified example 1, the object to be processed  40  can be held in a stabled manner. Further, the holding mechanism can be simplified. The rests of the configuration and the effects are the same as those in the description of the embodiment. 
     Modified Example 2 
     Next, a modified example 2 of the above-described embodiment will be described. In this modified example, each of the loading holding part and the unloading holding part for the object to be processed  40  is formed by a plurality of grooves. Grooves extending in the Y-axis direction are formed in the vicinity  12  of one end and the vicinity  13  of the other end of the top surface  11  of the stage  10 . 
       FIG. 18  is a plan view showing an example of a stage  10  according to the modified example 2 of the embodiment.  FIG. 19  is a cross-sectional view showing the example of the stage  10  according to the modified example 2 of the embodiment. As shown in  FIGS. 18 and 19 , grooves  27  extending in the Y-axis direction are formed in the top surface of the stage  10 . The grooves  27  are disposed in the vicinity  12  of one end and the vicinity  13  of the other end of the top surface  11  of the stage  10 . The loading/unloading apparatus  30  includes an arm part  33 . The loading/unloading apparatus  30  inserts the arm part  33  into the plurality of grooves  27  and thereby loads/unloads the object to be processed  40 . Specifically, the arm part  33  of the loading/unloading apparatus  30  for holding the object to be processed  40  is inserted into the grooves  27 . The tip of the arm part  33  is divided into, at the maximum, the same number of branches as the number of the grooves  27 . The branched parts of the arm part  33  extend in the Y-axis direction. 
     The loading/unloading apparatus  30  holds the object to be processed  40  over the arm part  33 . Then, when the object to be processed  40  is placed over the top surface  11  of the stage  10 , the branched parts of the arm part  33  are inserted into the grooves  27 . After the object to be processed  40  is placed over the top surface  11 , the loading/unloading apparatus  30  pulls out the arm part  33  from the grooves  27 . Further, when the object to be processed  40  is unloaded from the stage  10 , the branched parts of the arm part  33  are inserted into the grooves  27  below the top surface  11  over which the object to be processed  40  is placed. Then, the object to be processed  40 , which is placed over the stage  10 , is scooped by and put over the arm part  33 . The arm part  33  is pulled out from the grooves  27  while the object to be processed  40  are left placed over the arm part  33 . In this way, the object to be processed  40  is loaded and unloaded. 
     According to the laser processing apparatus  1  in accordance with the modified example 2, it is possible to reduce the control of the holding mechanism performed by the motion controller  15  and thereby further simplify the mechanism of the laser processing apparatus  1 . The rests of the configuration and the effects are the same as those in the descriptions of the embodiment and the modified example 1. 
     &lt;Method for Manufacturing Semiconductor Device&gt; 
     Next, as another embodiment, a method for manufacturing a semiconductor device by using the above-described laser processing apparatus  1  will be described. In this embodiment, a laser annealing apparatus is used as the laser processing apparatus  1 . The method for manufacturing a semiconductor device according to this embodiment includes the steps of: preparing an object to be processed  40  including a substrate and an amorphous film formed over the substrate; and crystallizing the amorphous film by irradiating the amorphous film with laser light. A substrate in which an amorphous semiconductor film is formed is used as the object to be processed  40 . For example, a glass substrate over which amorphous silicon is formed is used. In the step of crystallizing the amorphous film, a laser processing method using the laser processing apparatus  1  is carried out. 
     The semiconductor device is a semiconductor device including TFTs (Thin Film Transistors). In this case, it is possible to form a polysilicon film by applying laser light to an amorphous silicon film and thereby crystalizing the amorphous silicon film. 
       FIG. 20  is a cross-sectional view for explaining an example of a method for manufacturing a semiconductor device. The laser processing apparatus  1  according to the above-described embodiment is suitable for manufacturing a TFT array substrate. A method for manufacturing a semiconductor device including a TFT is described hereinafter. 
     Firstly, as shown in  FIG. 20( a ) , a gate electrode  202  is formed over a glass substrate  201 . For example, a metal thin film containing aluminum or the like can be used for the gate electrode  202 . Next, as shown in  FIG. 20( b ) , a gate insulating film  203  is formed over the gate electrode  202 . The gate insulating film  203  is formed so as to cover the gate electrode  202 . After that, as shown in  FIG. 20( c ) , an amorphous silicon film  204  is formed over the gate insulating film  203 . The amorphous silicon film  204  is disposed so as to be placed over the gate electrode  202  with the gate insulating film  203  interposed therebetween. As described above, firstly, a substrate in which an amorphous semiconductor film is formed is prepared (step A) 
     The gate insulating film  203  is, for example, a silicon nitride film (SiN x ), a silicon oxide film (SiO 2  film), or a laminated film thereof. Specifically, the gate insulating film  203  and the amorphous silicon film  204  are successively formed by a CVD (Chemical Vapor Deposition) method. The glass substrate  201  with the amorphous silicon film  204  deposited thereon is the object  40  to be processed in the laser processing apparatus  1 . 
     Then, as shown in  FIG. 20( d ) , a polysilicon film  205  is formed by applying laser light to the amorphous silicon film  204  by using the above-described laser processing apparatus  1  and thereby crystallizing the amorphous silicon film  204 . For example, as explained for the above-described laser irradiation method, a first position control signal for controlling the placement position of the substrate over the stage  10  is transmitted to the substrate loading/unloading apparatus  30  for the substrate (step B). Then, the substrate is placed in a first position over the stage  10  determined by the position control signal by the loading/unloading apparatus  30  (step C). After that, the substrate is conveyed over the stage  10  (step D), and the substrate is irradiated with laser light, so that the amorphous semiconductor film is converted into a polycrystalline state (step D). After the amorphous semiconductor film is converted into the polycrystalline state, the substrate is unloaded by the loading/unloading apparatus  30  (step F). 
     When not all the irradiation areas have not been irradiated with laser light, a second position control signal is transmitted to the loading/unloading apparatus  30  (step G), so that the substrate is placed in a second position different from the first position over the stage  10  determined by the second position control signal by the loading/unloading apparatus  30  (step H). Then, the substrate is conveyed to the laser light irradiation position over the stage  10  (step I) and the substrate is irradiated with laser light (step J). In this way, a polysilicon film  205  in which silicon is crystallized is formed over the gate insulating film  203 . 
     Note that it is possible to, when laser is applied to the glass substrate  201 , reduce the effect of warping thereof by using the laser processing apparatus  1  according to the above-described embodiment. Therefore, it is possible to prevent the amorphous silicon film  204  from being displaced from the depth of field (DOF) of the laser light applied thereto. Therefore, it is possible to form a uniformly-crystallized polysilicon film  205 . 
     After all the irradiation areas are irradiated with laser light and the semiconductor film is thereby converted into a polycrystalline state, the substrate is unloaded by the loading/unloading apparatus  30  (step K). 
     After that, as shown in  FIG. 20( e ) , an inter-layer insulating film  206 , a source electrode  207   a , and a drain electrode  207   b  are formed over the polysilicon film  205 . The inter-layer insulating film  206 , the source electrode  207   a , and the drain electrode  207   b  can be formed by an ordinary photolithography method or an ordinary film forming method. 
     It is possible to manufacture a semiconductor device including TFTs including a polycrystalline semiconductor film by using the above-described method for manufacturing a semiconductor device. Such a semiconductor device may be used for controlling a display. Note that the subsequent manufacturing process will vary depending on the device that is eventually manufactured, and therefore its description is omitted. 
     &lt;Organic EL Display&gt; 
     Next, as an example of a device using a semiconductor device including TFTs, an organic EL display device is described.  FIG. 21  is a cross section for explaining an outline of an organic EL display device, in which pixel circuits of the organic EL display device are illustrated in a simplified manner. The organic EL display device  300  shown in  FIG. 21  is an active-matrix-type display device in which a TFT is disposed in each pixel Px. 
     The organic EL display device  300  includes a substrate  310 , a TFT layer  311 , an organic layer  312 , a color filter layer  313 , and a sealing substrate  314 .  FIG. 21  shows a top-emission-type organic EL display device, in which the side of the sealing substrate  314  is located on the viewing side. Note that the following description is given to show an example of a configuration of an organic EL display device and this embodiment is not limited to the below-described configuration. For example, a semiconductor device according to this embodiment may be used for a bottom-emission-type organic EL display device. 
     The substrate  310  is a glass substrate or a metal substrate. The TFT layer  311  is provided over the substrate  310 . The TFT layer  311  includes TFTs  311   a  disposed in the respective pixels Px. Further, the TFT layer  311  includes wiring lines connected to the TFTs  311   a , and the like. The TFTs  311   a , the wirings, and the like constitute pixel circuits. Note that the TFT layer  311  corresponds to the TFT described above with reference to  FIG. 20 , and includes gate electrodes  202 , a gate insulating film  203 , a polysilicon film  205 , an inter-layer insulating film  206 , source electrodes  207   a , and drain electrodes  207   b.    
     The organic layer  312  is provided over the TFT layer  311 . The organic layer  312  includes an organic EL light-emitting element  312   a  disposed in each pixel Px. The organic EL light-emitting element  312   a  has, for example, a laminated structure in which an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode are laminated. In the case of the top emission type, the anode is a metal electrode and the cathode is a transparent conductive film made of ITO (Indium Tin Oxide) or the like. Further, in the organic layer  312 , separation walls  312   b  for separating organic EL light-emitting elements  312   a  are provided between pixels Px. 
     The color filter layer  313  is provided over the organic layer  312 . The color filter layer  313  includes color filters  313   a  for performing color displaying. That is, in each pixel PX, a resin layer colored in R (red), G (green), or B (blue) is provided as the color filter  313   a . When white light emitted from the organic layer  312  passes through the color filters  313   a , the white light is converted into light having RGB colors. Note that in the case of a three-color system in which organic EL light-emitting elements capable of emitting each color of RGB are provided in the organic layer  312 , the color filter layer  313  may be unnecessary. 
     The sealing substrate  314  is provided over the color filter layer  313 . The sealing substrate  314  is a transparent substrate such as a glass substrate and is provided to prevent deterioration of the organic EL light-emitting elements of the organic layer  312 . 
     Electric currents flowing through the organic EL light-emitting elements  312   a  of the organic layer  312  are changed by display signals supplied to the pixel circuits. Therefore, it is possible to control an amount of light emitted in each pixel Px by supplying a display signal corresponding to a display image to each pixel Px. As a result, it is possible to display a desired image. 
     Note that although the organic EL display device has been described above as an example of a device using a semiconductor device including TFTs, the semiconductor device including TFTs may be other types of display devices such as a liquid crystal display device. Further, cases where the laser processing apparatus  1  according to this embodiment is applied to a laser annealing apparatus have been described above. However, the laser processing apparatus  1  according to this embodiment can also be applied to apparatuses other than the laser annealing apparatus. 
     The present invention made by the inventors of the present application has been explained above in a concrete manner based on embodiments. However, the present invention is not limited to the above-described embodiments, and needless to say, various modifications can be made without departing from the spirit and scope of the present invention. 
     Further, the below-described matters are also included in the scope of the technical idea according to the embodiment or the modified example. 
     (Supplementary Note 1) 
     A laser processing apparatus comprising: 
     a stage including a top surface over which an object to be processed is moved from a vicinity of one end of the top surface to a vicinity of another end thereof along one direction in a plane parallel to the top surface; 
     a laser irradiation unit configured to apply laser light to the object to be processed moving over the top surface; and 
     a control unit configured to instruct a loading/unloading apparatus to place the object to be processed in a first position in the vicinity of the one end or in a second position in the vicinity of the one end, the loading/unloading apparatus being configured to place the object to be processed in the vicinity of the one end and unload the object to be processed from the vicinity of the other end, the second position being displaced from the first position in another direction orthogonal to the one direction by a predetermined length in a plane parallel to the top surface. 
     (Supplementary Note 2) 
     The laser processing apparatus described in Supplementary note 1, wherein the control unit selects the first position or the second position as a placement position of the object to be processed and instructs the loading/unloading to place the object to be processed in the selected placement position. 
     (Supplementary Note 3) 
     The laser processing apparatus described in Supplementary note 1, wherein when a loading/unloading control unit selects the first position or the second position as the placement position of the object to be processed, the control unit makes it possible to place the object to be processed in the placement position selected by the loading/unloading control unit, the loading/unloading control unit being configured to control loading/unloading of the object to be processed in the loading/unloading apparatus. 
     (Supplementary Note 4) 
     The laser processing apparatus described in any one of Supplementary notes 1 to 3, wherein 
     the stage is disposed inside a processing chamber including a loading gate and an unloading gate different from the loading gate, and 
     the control unit makes the loading/unloading apparatus carries in the object to be processed through the loading gate, places the object to be processed over the top surface, and carries out the object to be processed through the unloading gate. 
     (Supplementary Note 5) 
     The laser processing apparatus described in any one of Supplementary notes 1 to 4, wherein a part of the first position overlaps a part of the second position over the top surface. 
     (Supplementary Note 6) 
     The laser processing apparatus described in any one of Supplementary notes 1 to 5, wherein 
     the laser light has a line beam shape extending in the other direction, and 
     a length of an irradiation area on the object to be processed placed over the top surface in the other direction is longer than a length of the line beam, the irradiation area being an area that needs to be irradiated with the laser light. 
     (Supplementary Note 7) 
     The laser processing apparatus described in Supplementary note 6, wherein 
     the irradiation area includes a first irradiation part, a second irradiation part, and a third irradiation part each of which can be irradiated with the laser light by one transfer of the object to be processed in the one direction, 
     in the object to be processed, the second irradiation part is located between the first and third irradiation parts, 
     when the object to be processed placed in the first position is moved in the one direction, the first or third irradiation part is irradiated with the laser light, and 
     when the object to be processed placed in the second position is moved in the one direction, the second irradiation part is irradiated with the laser light. 
     (Supplementary Note 8) 
     The laser processing apparatus described in Supplementary note 6, wherein 
     the irradiation area includes a first irradiation part and a second irradiation part each of which can be irradiated with the laser light by one transfer of the object to be processed in the one direction, 
     when the object to be processed placed in the first position is moved in the one direction, the first irradiation part is irradiated with the laser light, and 
     when the object to be processed placed in the second position is moved in the one direction, the second irradiation part is irradiated with the laser light. 
     (Supplementary Note 9) 
     The laser processing apparatus described in any one of Supplementary notes 1 to 8, wherein a length of the object to be processed placed over the top surface in the other direction is 2,220 [mm] or longer. 
     (Supplementary Note 10) 
     The laser processing apparatus described in any one of Supplementary notes 1 to 9, wherein holding means is provided in at least one of the first and second positions over the top surface, the holding means being configured to protrude from the top surface and hold the object to be processed. 
     (Supplementary Note 11) 
     The laser processing apparatus described in Supplementary note 10, wherein the holding means is accommodated below the top surface when the object to be processed is moved in the one direction. 
     (Supplementary Note 12) 
     The laser processing apparatus described in Supplementary note 11, wherein 
     the stage comprises a grasping part disposed in the top surface, the grasping part being configured to grasp the object to be processed, and 
     the holding means is accommodated in such a manner that the closer it is located to the grasping part, the earlier it is accommodated. 
     (Supplementary Note 13) 
     The laser processing apparatus described in any one of Supplementary notes 10 to 12, wherein the holding means is a pusher pin. 
     (Supplementary Note 14) 
     The laser processing apparatus described in any one of Supplementary notes 10 to 12, wherein the holding means is a bar. 
     (Supplementary Note 15) 
     The laser processing apparatus described in any one of Supplementary notes 1 to 9, wherein a groove is formed in the vicinity of the one end of the top surface and the vicinity of the other end thereof, the groove being formed so that an arm part of the loading/unloading apparatus is inserted thereinto, the arm part being configured to hold the object to be processed. 
     (Supplementary Note 16) 
     The laser processing apparatus described in any one of Supplementary notes 1 to 15, wherein the object to be processed comprises a substrate and a semiconductor film formed over the substrate. 
     (Supplementary Note 17) 
     A laser processing method comprising the steps of: 
     (a) placing an object to be processed in a first position in a vicinity of one end of a stage, the stage including a top surface over which the object to be processed is moved from the vicinity of the one end of the top surface to vicinity of another end thereof along one direction in a plane parallel to the top surface; 
     (b) moving the object to be processed from the vicinity of the one end of the top surface to the vicinity of the other end thereof along the one direction; 
     (c) applying laser light to the object to be processed moving over the top surface; 
     (d) unloading the object to be processed from the vicinity of the other end of the top surface; 
     (e) placing the object to be processed in a second position in the vicinity of the one end of the top surface, the second position being displaced from the first position in another direction orthogonal to the one direction by a predetermined length in a plane parallel to the top surface, and 
     after the step (e), successively performing the step (b), the step (c), and the step (d). 
     (Supplementary Note 18) 
     The laser processing method described in Supplementary note 17, wherein 
     a control unit configured to instruct a loading/unloading apparatus to place the object to be processed in the vicinity of the one end and unload the object to be processed from the vicinity of the other end is used, 
     in the step (a), the control unit is made to instruct the loading/unloading apparatus to place the object to be processed in the first position, and 
     in the step (e), the control unit is made to instruct the loading/unloading apparatus to place the object to be processed in the second position. 
     (Supplementary Note 19) 
     The laser processing method described in Supplementary note 18, wherein 
     in the step (a), the control unit is made to select the first position as a placement position of the object to be processed and instruct the loading/unloading apparatus about the selected placement position, and 
     in the step (e), the control unit is made to select the second position as the placement position of the object to be processed and instruct the loading/unloading apparatus about the selected placement position. 
     (Supplementary Note 20) 
     A method for manufacturing a semiconductor device, comprising the steps of: 
     (A) preparing an object to be processed including a substrate and an amorphous film formed over the substrate; 
     (B) crystallizing the amorphous film by irradiating the amorphous film with laser light, wherein 
     the step (B) comprises the steps of: 
     (a) placing an object to be processed in a first position in a vicinity of one end of a stage, the stage including a top surface over which the object to be processed is moved from the vicinity of the one end of the top surface to vicinity of another end thereof along one direction in a plane parallel to the top surface; 
     (b) moving the object to be processed from the vicinity of the one end of the top surface to the vicinity of the other end thereof along the one direction; 
     (c) applying laser light to the object to be processed moving over the top surface; 
     (d) unloading the object to be processed from the vicinity of the other end of the top surface; 
     (e) placing the object to be processed in a second position in the vicinity of the one end of the top surface, the second position being displaced from the first position in another direction orthogonal to the one direction by a predetermined length in a plane parallel to the top surface, and 
     after the step (e), successively performing the step (b), the step (c), and the step (d). 
     This application is based upon and claims the benefit of priority from Japanese patent application No. 2018-002460, filed on Jan. 11, 2018, the disclosure of which is incorporated herein in its entirety by reference. 
     REFERENCE SIGNS LIST 
     
         
           1 ,  100  LASER PROCESSING APPARATUS 
           10  STAGE 
           11  TOP SURFACE 
           11   a  FIRST POSITION 
           11   b  SECOND POSITION 
           11   c  THIRD POSITION 
           11   d  FOURTH POSITION 
           12  ONE END-VICINITY 
           13  OTHER END-VICINITY 
           14  PUSHER PIN 
           14   a  FIRST PUSHER PIN DRIVER 
           14   b  SECOND PUSHER PIN DRIVER 
           15  MOTION CONTROLLER 
           16  GRASPING PART 
           17   a  LOADING PORT 
           17   b  UNLOADING PORT 
           18  PROCESSING CHAMBER 
           20  LASER IRRADIATION PART 
           21  LINE BEAM 
           22  LASER IRRADIATION UNIT CONTROLLER 
           23  DOOR VALVE 
           24  LEVITATING UNIT CONTROLLER 
           25  XYθ-STAGE 
           26  BAR 
           27  GROOVE 
           28   a  OPTICAL SYSTEM HOUSING 
           28   b  MIRROR 
           28   c  ENCLOSED PART 
           28   d  GAS BOX 
           28   e  GAS INLET 
           28   f  GAS 
           28   g  IRRADIATION WINDOW 
           28   h  SEALING WINDOW 
           30  LOADING/UNLOADING APPARATUS 
           31  LOADING/UNLOADING CONTROL UNIT 
           32  ROTATING APPARATUS 
           33  ARM PART 
           34  CASSETTE 
           40  OBJECT TO BE TREATED 
           41  FIRST IRRADIATION PART 
           42  SECOND IRRADIATION PART 
           43  THIRD IRRADIATION PART 
           45  PANEL 
           50  CONTROL UNIT 
           51  MAIN CONTROL UNIT 
           52  SUB CONTROL SECTION