Patent Publication Number: US-2022234160-A1

Title: Substrate processing apparatus and substrate processing method

Description:
TECHNICAL FIELD 
     The various aspects and embodiments described herein pertain generally to a substrate processing apparatus and a substrate processing method. 
     BACKGROUND 
     Patent Document 1 discloses a technique of grinding an outer periphery of a semiconductor wafer into an L-shape. The semiconductor wafer is formed by bonding two silicon wafers together, and a bevel of one of the silicon wafers is removed by the grinding. The purpose of removing the bevel is to suppress chipping or the like. 
     PRIOR ART DOCUMENT 
     
         
         Patent Document 1: Japanese Patent Laid-open Publication No. H09-216152 
       
    
     DISCLOSURE OF THE INVENTION 
     Problems to be Solved by the Invention 
     Exemplary embodiments provide a technique enabling to appropriately collect a processing residue generated when a processing tool is pressed onto an outer periphery of a substrate, to thereby maintain a clean state. 
     Means for Solving the Problems 
     In an exemplary embodiment, a substrate processing apparatus includes a chuck configured to hold a substrate horizontally; a processing unit configured to press a processing tool against an outer periphery of the substrate held by the chuck to process the substrate; and a lower cup configured to collect a processing residue falling from the substrate over an entire circumference of the substrate. The lower cup is provided with a discharge opening through which the processing residue is discharged. 
     Effect of the Invention 
     According to the exemplary embodiments, it is possible to appropriately collect the processing residue generated when the processing tool is pressed onto the outer periphery of the substrate, to thereby maintain a clean state. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view illustrating a thinning system according to an exemplary embodiment. 
         FIG. 2  is a cross sectional view illustrating a processing target substrate, a device layer and a support substrate according to the exemplary embodiment. 
         FIG. 3  is a flowchart illustrating a thinning method according to the exemplary embodiment. 
         FIG. 4A  is a cross sectional view illustrating an example of a laser processing shown in  FIG. 3 . 
         FIG. 4B  is a plan view illustrating positions of a first division surface and a second division surface shown in  FIG. 4A . 
         FIG. 5  is a cross sectional view illustrating an example of bevel removing shown in  FIG. 3 . 
         FIG. 6  is a cross sectional view illustrating an example of thinning shown in  FIG. 3 . 
         FIG. 7  is a plan view illustrating a bevel removing apparatus according to the exemplary embodiment. 
         FIG. 8  is a diagram showing the bevel removing apparatus of  FIG. 7  seen from the positive Y-axis side. 
         FIG. 9A  is a cross sectional view taken along a line IX-IX of  FIG. 7 , showing an opening position of an upper cover. 
         FIG. 9B  is a cross sectional view taken along the line IX-IX of  FIG. 7 , showing a closing position of the upper cover. 
         FIG. 10  is a side view illustrating a lower cup and a discharge pipe. 
         FIG. 11  is a cross sectional view illustrating an example of a gas flow formed around an outer periphery of a combined substrate when a processing is performed. 
         FIG. 12  is a functional block diagram illustrating constituent components of a controller according to the exemplary embodiment. 
         FIG. 13  is an enlarged view of a processing unit shown in  FIG. 9B . 
         FIG. 14A  is a plan view illustrating a pressing device according to the exemplary embodiment. 
         FIG. 14B  is a cross sectional view taken along a line XIVB-XIVB of  FIG. 14A . 
         FIG. 15  is a plan view illustrating an example of a range of the outer periphery of the combined substrate that comes into contact with a blade. 
         FIG. 16  is a cross sectional view showing a state in which a degree of horizontality is measured by a measuring device according to the exemplary embodiment. 
         FIG. 17  is a cross sectional view showing a state in which a height is measured by a measuring device according to the exemplary embodiment. 
         FIG. 18  is a cross sectional view illustrating a modification example of the bevel removing and the thinning shown in  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings. In the various drawings, same or corresponding parts will be assigned same or corresponding reference numerals, and redundant description will be omitted. In the present specification, the X-axis direction, the Y-axis direction and the Z-axis direction are orthogonal to each other. The X-axis direction and the Y-axis direction are horizontal directions, whereas the Z-axis direction is a vertical direction. 
       FIG. 1  is a plan view illustrating a thinning system according to an exemplary embodiment. The thinning system  1  is configured to thin a processing target substrate  100 . Further, the thinning system  1  is also configured to remove a bevel  104  of the processing target substrate  100  before thinning the processing target substrate  100 . The bevel  104  refers to a chamfered portion. Although the bevel  104  is a R-chamfered portion in  FIG. 2 , it may be a C-chamfered portion. 
       FIG. 2  is a cross sectional view illustrating a processing target substrate, a device layer and a support substrate according to the exemplary embodiment. The processing target substrate  100  is a semiconductor substrate such as, but not limited to, a silicon wafer or a compound semiconductor wafer. A device layer  110  is previously formed on one side of the processing target substrate  100 . The device layer  110  is, for example, an electronic circuit. Hereinafter, a main surface of the processing target substrate  100  on which the device layer  110  is formed will be referred to as a first main surface  101 . Further, a main surface opposite to the first main surface  101  will be referred to as a second main surface  102 . The second main surface  102  is brought closer to the first main surface  101  by the thinning of the processing target substrate  100 . 
     An oxide layer  120  is formed on a surface of the device layer  110  on the opposite side to the processing target substrate  100 . The oxide layer  120  is formed to be smaller than the processing target substrate  100  in diameter in order to smoothly remove the bevel  104  of the processing target substrate  100 . The oxide layer  120  is, for example, a silicon oxide layer. The silicon oxide layer is formed of, for example, tetraethyl orthosilicate (TEOS). 
     Like the processing target substrate  100 , a support substrate  130  is a semiconductor substrate such as a silicon wafer or a compound semiconductor wafer. The support substrate  130  is bonded to the processing target substrate  100  with the device layer  110  therebetween. An oxide layer  140  is formed on a surface of the support substrate  130  facing the device layer  110 . The oxide layer  140  is formed in the same manner as the oxide layer  120 . In addition, a non-illustrated device layer may be formed between the oxide layer  140  and the support substrate  130 . 
     A combined substrate  150  includes the processing target substrate  100 , the device layer  110 , the two oxide layers  120  and  140 , and the support substrate  130 . The two oxide layers  120  and  140  are bonded to each other by a heat treatment. In addition, the combined substrate  150  may have only one of the two oxide layers  120  and  140 . 
     As depicted in  FIG. 1 , the thinning system  1  includes a carry-in/out station  2 , a first processing station  3 , a second processing station  6 , and a control device  9 . The carry-in/out station  2 , the first processing station  3 , and the second processing station  6  are arranged in this order from the negative X-axis side toward the positive X-axis side. 
     The carry-in/out station  2  is equipped with a plurality of placing members  21 . These placing members  21  are arranged side by side in the Y-axis direction. A cassette CS is placed on each of the placing members  21 . The cassette CS accommodates therein a plurality of combined substrates  150  at an interval therebetween in a vertical direction. Here, the number of the placing members  21  is not particularly limited. Likewise, the number of the cassettes CS is not particularly limited, either. 
     Moreover, the carry-in/out station  2  is equipped with a transfer section  23 . The transfer section  23  is disposed next to the placing members  21 , for example, on the positive X-axis side of the placing members  21 . Also, the transfer section  23  is positioned next to a delivery section  26 , for example, on the negative X-axis side of the delivery section  26 . The transfer section  23  is equipped with a transfer device  24  inside. 
     The transfer device  24  is equipped with a holder configured to hold the combined substrate  150 . The holder is configured to be movable in horizontal directions (both in the X-axis direction and the Y-axis direction) and a vertical direction and pivotable around a vertical axis. 
     The transfer device  24  is configured to transfer the combined substrates  150  between the plurality of cassettes CS placed on the plurality of placing members  21  and the delivery section  26 . 
     Further, the carry-in/out station  2  is equipped with the delivery section  26 . The delivery section  26  is disposed next to the transfer section  23 , for example, on the positive X-axis side of the transfer section  23 . Also, the delivery section  26  is positioned next to the first processing station  3 , for example, on the negative X-axis side of the first processing station  3 . The delivery section  26  has a transition device  27 . The transition device  27  temporarily accommodates therein the combined substrate  150 . A plurality of transition devices  27  may be stacked in the vertical direction. The layout and the number of the transition devices  27  are not particularly limited. 
     The first processing station  3  is equipped with a processing block  4 . The processing block  4  includes a laser processing apparatus  41 , a cleaning apparatus  42 , and an etching apparatus  43 . As shown in  FIG. 4A , the laser processing apparatus  41  is configured to form condensing points P of a laser beam LB in the processing target substrate  100 , and form a first modification layer M 1 , a second modification layer M 2 , and a third modification layer M 3  at the condensing points P. The cleaning apparatus  42  is configured to clean the second main surface  102  of the thinned processing target substrate  100 . The etching apparatus  43  is configured to etch the second main surface  102  of the thinned processing target substrate  100 . Here, the layout and the number of the various apparatuses constituting the processing block  4  are not limited to the layout and the number shown in  FIG. 1 . 
     The first processing station  3  is equipped with a transfer section  5 . The transfer section  5  is provided next to the transition device  27  of the carry-in/out station  2 , for example, on the positive X-axis side of the transition device  27 . Further, the transfer section  5  is positioned next to the processing block  4 , for example, on the positive Y-axis side of the processing block  4 . Also, the transfer section  5  is disposed next to the second processing station  6 , for example, on the negative X-axis side of the second processing station  6 . The transfer section  5  is equipped with a first transfer device  51  inside. 
     The first transfer device  51  is equipped with a holder configured to hold the combined substrate  150 . The holder is configured to be movable in the horizontal directions (both in the X-axis direction and the Y-axis direction) and a vertical direction and pivotable around a vertical axis. The first transfer device  51  transfers the combined substrate  150  to/from the transition device  27  of the carry-in/out station  2 , the processing block  4  of the first processing station  3 , and a bevel removing apparatus  61  of the second processing station  6 . 
     The second processing station  6  has the bevel removing apparatus  61  and a thinning apparatus  62 . As illustrated in  FIG. 5 , the bevel removing apparatus  61  is configured to remove the bevel  104  of the processing target substrate  100  by applying an external force to the processing target substrate  100  to extend a first crack C 1  formed starting from the first modification layer M 1  and a second crack C 2  formed starting from the second modification layer M 2 . As shown in  FIG. 6 , the thinning apparatus  62  is configured to thin the processing target substrate  100  by applying an external force to the processing target substrate  100  to extend a third crack C 3  formed starting from the third modification layer M 3 . The thinning apparatus  62  is equipped with, for example, a second transfer device  63  and a grinding apparatus  64 . The second transfer device  63  is configured to transfer the combined substrate  150  from the bevel removing apparatus  61  to the grinding apparatus  64 . The grinding apparatus  64  is configured to grind the second main surface  102  of the thinned processing target substrate  100 , and thus further is configured to thin the processing target substrate  100 . The thinned processing target substrate  100  is transferred into the cleaning apparatus  42  by the second transfer device  63 . Here, the layout and the number of the various apparatuses in the second processing station  6  are not limited to the layout and the number shown in  FIG. 1 . For example, the thinning apparatus  62  may be provided separately from the second transfer device  63 . 
     The control device  9  is, for example, a computer, and includes a CPU (Central Processing Unit)  91  and a recording medium  92  such as a memory, as shown in  FIG. 1 . The recording medium  92  stores therein a program for controlling various kinds of processings performed in the thinning system  1 . The control device  9  controls an operation of the thinning system  1  by allowing the CPU  91  to execute the program stored in the recording medium  92 . Further, the control device  9  includes an input interface  93  and an output interface  94 . The control device  9  receives a signal from the outside through the input interface  93 , and transmits a signal to the outside through the output interface  94 . 
     The program is stored in, for example, a computer-readable recording medium, and installed from this recording medium to the recording medium  92  of the control device  9 . The computer-readable recording medium may be, by way of non-limiting example, a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), a memory card, or the like. Further, the program may be downloaded from a server through the Internet and installed to the recording medium  92  of the control device  9 . 
       FIG. 3  is a flowchart illustrating a thinning method according to the exemplary embodiment. The thinning method includes, for example, processes S 101  to S 107  shown in  FIG. 3 . These processes S 101  to S 107  are performed under the control of the control device  9 . 
     First, the transfer device  24  takes out the combined substrate  150  from the cassette CS placed on the placing member  21 , and transfers it into the transition device  27 . Then, the first transfer device  51  receives the combined substrate  150  from the transition device  27  and transfers it into the laser processing apparatus  41 . 
     Thereafter, the laser processing apparatus  41  laser-processes the processing target substrate  100  (S 101  of  FIG. 3 ). As shown in  FIG. 4A , the laser processing apparatus  41  forms the condensing points P of the laser beam LB inside the processing target substrate  100  from the opposite side (e.g., the upper side) to the device layer  110  with the processing target substrate  100  therebetween, and forms the modification layers at the condensing points P. The laser beam LB is pulse-oscillated, and the modification layers are formed at an interval therebetween. 
     When the processing target substrate  100  is single crystal silicon, an infrared ray is used as the laser beam LB. The Infrared ray has high transmittivity for the single crystal silicon, and an amorphous silicon layer is formed at a condensing point P of the infrared ray as a modification layer. The modification layer serves as a starting point for dividing the processing target substrate  100 . The division of the processing target substrate  100  is carried out by applying a stress. 
       FIG. 4A  is a cross sectional view showing an example of the laser processing shown in  FIG. 3 .  FIG. 4B  is a plan view illustrating positions of a first division surface and a second division surface shown in  FIG. 4A . 
     In the laser processing apparatus  41 , the first modification layer M 1  is formed on a first division surface D 1  that divides the processing target substrate  100  in a diametrical direction thereof. The first division surface D 1  is a circumferential surface concentric with an outer periphery  103  of the processing target substrate  100  as shown in  FIG. 4B . As shown in  FIG. 4A , the first modification layer M 1  is plural in number, and these multiple first modification layers M 1  are formed at intervals therebetween in the circumferential direction and the thickness direction of the processing target substrate  100 . When the first modification layers M 1  are formed, the first crack C 1  connecting the first modification layers M 1  is formed. The first crack C 1  may be formed so as to reach the first main surface  101  and not to reach the second main surface  102 . 
     The first division surface D 1  is positioned at an inner side than the bevel  104  of the processing target substrate  100  in the diametrical direction. The bevel  104  can be removed by removing a portion  105  at an outer side than the first division surface D 1  in the diametrical direction. The processing target substrate  100  may be thinned after the bevel  104  is removed, so that generation of a so-called knife edge  106  can be suppressed. 
     Further, as shown in  FIG. 4B , the laser processing apparatus  41  forms the second modification layer M 2  on a plurality of second division surfaces D 2  extending radially from the first division surface D 1  to the outer periphery  103  of the processing target substrate  100 . The second modification layer M 2  is plural in number, and these multiple second modification layers M 2  are formed at intervals therebetween in the diametrical direction and the thickness direction of the processing target substrate  100 , as illustrated in  FIG. 4A . When the second modification layers M 2  are formed, the second crack C 2  connecting the second modification layers M 2  is formed. Although the number of the second division surfaces D 2  is four in  FIG. 4B , it is not particularly limited as long as more than one second division surface D 2  is provided. If the number of the second division surfaces D 2  is more than one, the ring-shaped peripheral portion  105  can be removed by being divided into multiple arc-shaped fragments  107 . 
     Moreover, the laser processing apparatus  41  forms the third modification layer M 3  on a third division surface D 3  that divides the processing target substrate  100  in the thickness direction thereof, as shown in  FIG. 4A . The third division surface D 3  is a flat surface parallel to the first main surface  101  and the second main surface  102  of the processing target substrate  100 . The third modification layers M 3  is plural in number, and these multiple third modification layers M 3  are formed at intervals therebetween in the circumferential direction and the diametrical direction of the processing target substrate  100 , and are arranged concentrically. Alternatively, the third modification layers M 3  may be arranged in a spiral shape. When the third modification layers M 3  are formed, the third crack C 3  connecting the third modification layers M 3  is formed. 
     The order of the formation of the first modification layers M 1 , the second modification layers M 2 , and the third modification layers M 3  is not particularly limited. After the formation of the first modification layers M 1 , the second modification layers M 2  and the third modification layers M 3 , the first transfer device  51  receives the combined substrate  150  from the laser processing apparatus  41 , and transfers it to the bevel removing apparatus  61 . 
       FIG. 5  is a cross sectional view illustrating an example of bevel removing shown in  FIG. 3 . As shown in  FIG. 5 , the bevel removing apparatus  61  applies an external force to the processing target substrate  100  with a blade  160  used as a processing tool. The blade  160  is inserted between the processing target substrate  100  and the support substrate  130 , and it does not cut the processing target substrate  100 . By inserting the blade  160 , the first crack C 1  starting from the first modification layer M 1  and the second crack C 2  starting from the second modification layer M 2  are extended to thereby remove the bevel  104  of the processing target substrate  100  (S 102  of  FIG. 3 ). As the bevel  104  is removed, the processing target substrate  100  is reduced in size in the diametrical direction. The outer periphery  103  of the processing target substrate  100  reduced in size in the diametrical direction coincides with the first division surface D 1 . Here, although the blade  160  is used as the processing tool in the present exemplary embodiment, a roller may be used instead of the blade. In the present exemplary embodiment, the processing tool is pressed against the outer periphery of the processing target substrate  100  from a lateral side of the processing target substrate  100 . However, the processing tool may be pressed against the outer periphery of the processing target substrate  100  from above the processing target substrate  100 . 
     Subsequently, the bevel removing apparatus  61  images the outer periphery  103  of the processing target substrate  100  (S 103  of  FIG. 3 ), and image-processes the captured image (S 104  of  FIG. 3 ). Through this image processing, the removal of the bevel  104  can be confirmed. Also, by this image processing, it can be confirmed whether the third crack C 3  has reached the outer periphery  103  of the processing target substrate  100 , that is, the first division surface D 1 . Then, the second transfer device  63  receives the combined substrate  150  from the bevel removing apparatus  61 , and transfers it to the grinding apparatus  64 . 
     The grinding apparatus  64  includes, for example, a rotary table  641 , two chucks  642 , and a processing unit  643 , as depicted in  FIG. 1 . The number and the layout of the chucks  642  are not particularly limited. Further, the number and the layout of the processing unit  643  are not particularly limited, either. 
     The rotary table  641  is rotated about a vertical rotation center line Z 1 . The two chucks  642  are disposed with the rotation center line Z 1  of the rotary table  641  therebetween. The two chucks  642  are rotated along with the rotary table  641  and moved to a carry-in/out position AO and a grinding position A 1  alternately. 
     The carry-in/out position AO serves as a carry-in position where the combined substrate  150  is carried in by the second transfer device  63  and a carry-out position where the combined substrate  150  is carried out by the second transfer device  63 . Meanwhile, the grinding position A 1  is a position where grinding of the processing target substrate  100  is performed by the processing unit  643 . 
       FIG. 6  is a cross sectional view illustrating an example of thinning shown in  FIG. 3 . At the carry-in/out position AO, the grinding apparatus  64  and the second transfer device  63  divide the processing target substrate  100  along the third division surface D 3 , as shown in  FIG. 6 , so that the processing target substrate  100  is thinned (S 105  of  FIG. 3 ). The thinning apparatus  62  includes the second transfer device  63  and the grinding apparatus  64  as stated above. 
     In the state that the processing target substrate  100  is held by the second transfer device  63  from above and held by the grinding apparatus  64  from below, a holder  631  of the second transfer device  63  is raised with respect to the chuck  642  of the grinding apparatus  64 . As a result, the third crack C 3  expands in a planar shape, and adjacent third cracks C 3  are connected to each other, so that the processing target substrate  100  is divided along the third division surface D 3 . 
     The holder  631  of the second transfer device  63  may be raised while being rotated around a vertical rotation axis in order to cut the processing target substrate  100  along the third division surface D 3 . Instead of the holder  631  of the second transfer device  63 , the chuck  642  of the grinding apparatus  64  may be rotated. In addition, both the holder  631  of the second transfer device  63  and the chuck  642  of the grinding apparatus  64  may be rotated in opposite directions. 
     The device layer  110  is formed on the first main surface  101  of the processing target substrate  100  divided along the third division surface D 3 . Further, irregularities generated when the first cracks C 1  are connected are formed on the second main surface  102  of the processing target substrate  100  divided along the third division surface D 3 . 
     Next, the grinding apparatus  64  grinds the second main surface  102  of the processing target substrate  100 . The grinding is a part of the thinning. The second main surface  102  of the processing target substrate  100  is planarized by the grinding. A plate thickness of the processing target substrate  100  after being ground is set to a required value in consideration of the usage of the processing target substrate  100  or the like. A variation amount in the plate thickness of the processing target substrate  100  before and after the grinding, that is, a grinding allowance is set so that the third modification layers M 3  are removed by the grinding. Then, the second transfer device  63  receives the combined substrate  150  from the grinding apparatus  64 , and transfers it to the cleaning apparatus  42 . 
     Subsequently, the cleaning apparatus  42  cleans the second main surface  102  of the thinned processing target substrate  100  (S 106  of  FIG. 3 ). The cleaning may be, for example, scrub-cleaning. By cleaning the second main surface  102 , it is possible to remove particles or the like generated in the thinning. Thereafter, the first transfer device  51  receives the combined substrate  150  from the cleaning apparatus  42 , and transfers it to the etching apparatus  43 . 
     Next, the etching apparatus  43  etches the second main surface  102  of the thinned processing target substrate  100  (S 107  of  FIG. 3 ). The etching is, for example, wet etching. By etching the second main surface  102 , a damage layer caused by the thinning can be removed. 
     Thereafter, the first transfer device  51  receives the combined substrate  150  from the etching apparatus  43 , and transfers it to the transition device  27 . Then, the transfer device  24  receives the combined substrate  150  from the transition device  27 , and transfers it to the cassette CS disposed on the placing member  21 . Then, the current processing is ended. 
     Here, the order of the above-stated processes S 101  to S 107  is not limited to the example shown in  FIG. 3 . By way of example, the formation of the first modification layer M 1  and the second modification layer M 2 , the division along the first division surface D 1  and the second division surface D 2 , the formation of the third modification layer M 3 , and the division along the third division surface D 3  may be performed in this sequence. In addition, the grinding may be performed without performing the formation of the third modification layer M 3  and the division along the third division surface D 3 . That is, the thinning may be carried out only by the grinding. Furthermore, the thinning may include only the division along the third division surface D 3  without including the grinding. 
       FIG. 7  is a plan view showing the bevel removing apparatus according to the exemplary embodiment. In  FIG. 7 , white arrows indicate a carrying-in direction and a carrying-out direction of the combined substrate  150 . The carrying-in direction and the carrying-out direction are, for example, directions perpendicular to each other.  FIG. 8  illustrates the bevel removing apparatus of  FIG. 7  seen from the positive Y-axis side. In  FIG. 8 , in order to show a first storage table  250  and a second storage table  260 , only a part of an internal transfer mechanism  270  shown in  FIG. 7  is illustrated.  FIG. 9A  is a cross sectional view taken along a line IX-IX of  FIG. 7 , showing an opening position of an upper cover, and  FIG. 9B  is a cross sectional view taken along the line IX-IX of  FIG. 7 , showing a closing position of the upper cover. 
     The bevel removing apparatus  61 , which is a substrate processing apparatus, removes the bevel  104  of the processing target substrate  100  by pressing the horizontal blade  160  against an outer periphery of the combined substrate  150 , as illustrated in  FIG. 5 . The blade  160  is inserted between the processing target substrate  100  and the support substrate  130 . Hereinafter, the processing by the blade  160  will be simply referred to as “processing.” The bevel removing apparatus  61  includes a base  210 , a chuck  220 , a rotating mechanism  230 , a protective cup  240 , the first storage table  250 , the second storage table  260 , and the internal transfer mechanism  270 , as illustrated in  FIG. 7 ,  FIG. 8 ,  FIG. 9A  and  FIG. 9B . 
     As shown in  FIG. 9A  and  FIG. 9B , the base  210  is, for example, a horizontal board, and it supports the protective cup  240  with at least one supporting column  211  therebetween. The protective cup  240  has a cylindrical member  241  having a vertical cylindrical shape; and a lid  242  that closes an opening at a lower end of the cylindrical member  241 . The protective cup  240  accommodates a rotating mechanism  230  inside the cylindrical member  241 , protecting the rotating mechanism  230  from processing residues. The rotating mechanism  230  rotates the chuck  220  about a vertical rotation shaft  231 . 
     The chuck  220  holds the processing target substrate  100  horizontally from below with the second main surface  102  of the processing target substrate  100  facing upwards, as shown in  FIG. 11 . The chuck  220  holds the processing target substrate  100  with the support substrate  130  therebetween. The chuck  220  is, for example, a vacuum chuck, but it may be an electrostatic chuck, a mechanical chuck, or the like. The processing target substrate  100  is processed while being held by the chuck  220 . 
     As shown in  FIG. 8 , the first storage table  250  receives and stores the combined substrate  150  before being processed carried from the outside by the first transfer device  51 . The first storage table  250  includes a plurality of first supporting columns  251  fixed to the base  210 ; and a first horizontal plate  252  supported horizontally by the plurality of first supporting columns  251 . A difference in height between a position where the combined substrate  150  is stored on the first storage table  250  and a position where the combined substrate  150  is held on the chuck  220  can be reduced by the first supporting columns  251 . As a result, when transferring the combined substrate  150  with the internal transfer mechanism  270 , an elevating operation can be reduced. 
     The first storage table  250  has three or more first guide pins  253  for performing a center alignment of the combined substrate  150 . The three or more first guide pins  253  are spaced apart from each other in the circumferential direction of the combined substrate  150 , and each has a tapered surface that narrows whet it goes upwards. The center alignment of the combined substrate  150  is performed by these tapered surfaces. 
     The first storage table  250  has three or more first supporting pins  254  for supporting the combined substrate  150 . The three or more first supporting pins  254  support the combined substrate  150  whose center alignment is performed by the three or more first guide pins  253  such that the combined substrate  150  is lifted from the first horizontal plate  252  so as not to be in contact with the first horizontal plate  252 . A gap is formed between the first horizontal plate  252  and the combined substrate  150 . Further, the first storage table  250  may have one first support member for supporting a central portion of the combined substrate  150  instead of the three or more first supporting pins  254 . 
     The first transfer device  51  has a holder  52  configured to hold the combined substrate  150 . The holder  52  is formed to have, for example, a bifurcated fork shape, and holds the combined substrate  150  horizontally from below with the second main surface  102  of the processing target substrate  100  facing upwards. After placing the combined substrate  150  on the first storage table  250 , the holder  52  releases attraction of the combined substrate  150 . Then, the holder  52  is lowered slightly and taken out from the gap formed between the combined substrate  150  and the first horizontal plate  252 . 
     In addition, although the first supporting pins  254  do not attract the combined substrate  150  in the present exemplary embodiment, they may be configured to attract the combined substrate  150 . That is, the first supporting pins  254  may serve as an attracting unit configured to attract the combined substrate  150 . Since the first supporting pins  254  can start attracting the combined substrate  150  before the first transfer device  51  releases the attraction of the combined substrate  150 , position deviation of the combined substrate  150  can be suppressed when the combined substrate  150  is transferred. Thus, as compared to the case where the first guide pins  253  are used, accuracy of the center alignment of the combined substrate  150  can be improved. The first support member, instead of the first supporting pins  254 , may be configured as the attracting unit. 
     The second storage table  260  stores the combined substrate  150  after being processed until the processed combined substrate  150  is taken out to the outside by the second transfer device  63 . As shown in  FIG. 8 , the second storage table  260  includes a plurality of second supporting columns  261  fixed to the first horizontal plate  252  of the first storage table  250 ; and a second horizontal plate  262  supported horizontally by the second supporting columns  261 . Since the first storage table  250  and the second storage table  260  are stacked in the vertical direction, the bevel removing apparatus  61  can be downsized when viewed in the vertical direction. Further, the arrangement of the first storage table  250  and the second storage table  260  may be reversed, so the first storage table  250  may be disposed on top of the second storage table  260 . 
     The second storage table  260  has three or more second guide pins  263  for performing center alignment of the combined substrate  150 . The three or more second guide pins  263  are spaced apart from each other in the circumferential direction of the combined substrate  150 , and each has a tapered surface that narrows when it goes upwards. The center alignment of the combined substrate  150  is performed by these tapered surfaces. 
     The second storage table  260  has three or more second supporting pins  264  for supporting the combined substrate  150 . The three or more second supporting pins  264  support the combined substrate  150  whose center alignment is performed by the three or more second guide pins  263  such that the combined substrate  150  is lifted from the second horizontal plate  262  so as not to be in contact with the second horizontal plate  262 . A gap is formed between the second horizontal plate  262  and the combined substrate  150 . Here, the second storage table  260  may have one second support member for supporting the central portion of the combined substrate  150  instead of the three or more second supporting pins  264 . 
     As shown in  FIG. 6 , the second transfer device  63  includes the holder  631  configured to hold the combined substrate  150  horizontally. The holder  631  is formed in, for example, a disk shape, and attracts the entire top surface of the combined substrate  150  from above. The holder  631  receives the combined substrate  150  from the second storage table  260 , rises with the combined substrate  150  attracted thereto, and moves to the outside of the bevel removing apparatus  61 . 
     In addition, as mentioned above, when the thinning apparatus  62  is provided separately from the second transfer device  63 , the holder  631  of the second transfer device  63  may be formed to have a bifurcated fork shape, like the holder  52  of the first transfer device  51 , and may be configured to hold the combined substrate  150  horizontally from below with the second main surface  102  of the processing target substrate  100  facing upwards. In this case, after being inserted into the gap formed between the combined substrate  150  and the second horizontal plate  262 , the holder  631  rises and receives the combined substrate  150  from the second storage table  260 . 
     Additionally, although the second supporting pins  264  do not attract the combined substrate  150  in the present exemplary embodiment, they may be configured to attract the combined substrate  150 . That is, the second supporting pins  264  may serve as an attracting unit configured to attract the combined substrate  150 . Since the second supporting pins  264  can start the attraction of the combined substrate  150  before the second transfer device  63  releases the attraction of the combined substrate  150 , the position deviation of the combined substrate  150  can be suppressed when the combined substrate  150  is transferred. Thus, as compared to the case where the second guide pins  263  are used, the accuracy of the center alignment of the combined substrate  150  can be improved. Here, the second support member, instead of the second supporting pins  264 , may be configured as the attracting unit. 
     The internal transfer mechanism  270  serves to transfer the combined substrate  150  before being processed from the first storage table  250  to the chuck  220 , and also serves to transfer the combined substrate  150  after being processed from the chuck  220  to the second storage table  260 . Since the internal transfer mechanism  270  carries the combined substrate  150  to/from the chuck  220 , there is no such restriction that the chuck  220  needs to be installed in a range accessible by the first transfer device  51  and the second transfer device  63 . Therefore, the degree of freedom in selecting the installation position of the chuck  220  is high. 
     As shown in  FIG. 7 , the internal transfer mechanism  270  includes, for example, a revolving arm  271  configured to be revolved about a revolving axis Z 2 ; and a holder  272  mounted to a leading end of the revolving arm  271 . The revolving arm  271  and the holder  272  are can be revolved and, also, movable up and down. 
     The holder  272  is configured to hold the combined substrate  150  horizontally from above with the second main surface  102  of the processing target substrate  100  facing upwards. Since the holder  272  and the chuck  220  hold the combined substrate  150  from the opposite sides, one can attract the combined substrate  150  while the other already attracts the combined substrate  150 . Thus, it is possible to reduce the position deviation of the combined substrate  150  when the combined substrate  150  is transferred. 
     In order to scale down the holder  272  such that the holder  272  does not touch the second supporting columns  261  of the second storage table  260  or the like when it is revolved, the holder  272  may be configured not to attract the entire top surface of the combined substrate  150  but to attract, for example, the center of the combined substrate  150 . The holder  272  is formed to have, for example, a disk shape, and has a diameter smaller than the diameter of the combined substrate  150 , for example. Moreover, the first supporting columns  251  and the second supporting columns  261  are arranged at positions where they do not interfere with the revolving of the revolving arm  271  and the holder  272 . 
     According to the present exemplary embodiment, since the first storage table  250  and the second storage table  260  are separately provided, multiple combined substrates  150  can be accommodated in the bevel removing apparatus  61 . Thus, a combined substrate  150  before being processed can be carried in before a combined substrate  150  after being processed is completely carried out. That is, since the combined substrate  150  before being processed can always be prepared in the bevel removing apparatus  61 , the number of the combined substrates processed per unit time can be increased. 
     Also, according to the present exemplary embodiment, since the first storage table  250  and the second storage table  260  are provided separately, carrying the combined substrate  150  before being processed onto the first storage table  250  from the outside and carrying the combined substrate  150  after being processed from the second storage table  260  to the outside can be performed at the same time. At this time, the first storage table  250  receives the combined substrate  150  before being processed from the first transfer device  51 , and the second storage table  260  hands the combined substrate  150  after being processed over to the second transfer device  63 . Since the plurality of processes can be performed simultaneously, the number of the combined substrates processed per unit time can be improved. 
     Furthermore, according to the present exemplary embodiment, since the chuck  220 , the first storage table  250 , and the second storage table  260  are separately provided, the following processes (1) and (2) can be also performed. (1) Carrying the combined substrate  150  before being processed from the outside onto the first storage table  250  and transferring the combined substrate  150  after being processed from the chuck  220  onto the second storage table  260  are performed simultaneously. (2) Transferring the combined substrate  150  before being processed from the first storage table  250  onto the chuck  220  and carrying the combined substrate  150  after being processed from the second storage table  260  to the outside are performed simultaneously. 
     As depicted in  FIG. 9A  and  FIG. 9B , the bevel removing apparatus  61  includes a lower cup  280 , and the lower cup  280  collects the processing residues falling from the combined substrate  150  over the entire circumference of the combined substrate  150 . The processing residues are generated due to the processing using the blade  160 , and includes, for example, at least one of the fragments  107  and dust. Since the combined substrate  150  is rotated along with the chuck  220  during the processing, the processing residues may fall at various rotation angles. Since the lower cup  280  collects the processing residues falling from the combined substrate  150  over the entire circumference of the combined substrate  150  as mentioned above, the processing residues can be collected reliably, so that the bevel removing apparatus  61  and the combined substrate  150  can be maintained clean. 
     The lower cup  280  has a lower cylindrical member  281  which is larger than the combined substrate  150  when viewed from above. The lower cylindrical member  281  is formed in a cylindrical shape so as to surround the combined substrate  150  held by the chuck  220 , when viewed from above. The lower cylindrical member  281  may have a groove  282  to avoid interference between the lower cylindrical member  281  and a processing unit  330 . As the lower cylindrical member  281  can be given a small diameter, the lower cup  280  can be downsized. The lower cylindrical member  281  may be disposed below the combined substrate  150  in order to avoid interference with the revolving arm  271  and the holder  272 . 
     The lower cup  280  has a lower lid  283  that closes an opening at a lower end of the lower cylindrical member  281 . The lower lid  283  is provided with a discharge opening  284  for discharging the processing residues. Since the discharge opening  284  is formed, deposition of the processing residues inside the lower cup  280  can be suppressed. The lower lid  283  has the discharge opening  284  in the center thereof, and has, over the entire circumference of the lower cylindrical member  281 , an inclined surface  285  that slopes downwards as it goes from the lower cylindrical member  281  toward the discharge opening  284 . The inclined surface  285  is formed in, for example, a conical shape. As compared to a case where the discharge opening  284  is provided at one end of the lower lid  283 , it is possible to form the inclined surface  285  with the same height difference and a steep inclination, thus allowing the processing residues to fall down easily. Alternatively, as compared to the case where the discharge opening  284  is provided at one end of the lower lid  283 , it is possible to form the inclined surface  285  having the same inclination and a small height difference, so that a size of the lower lid  283  in the vertical direction can be reduced. 
       FIG. 10  is a side view illustrating an example of the lower cup and a discharge pipe. The lower cup  280  is formed of a conductive material such as a metal, formed of an insulating material and coated with an anti-static agent, or formed of a mixture of an insulating material and an anti-static agent. The anti-static agent is a chemical agent which suppresses accumulation of static electricity by an action of a surfactant, for example, and it adsorbs moisture in the air into a surface of the insulating material to reduce electrical resistance. Since the lower cup  280  can be suppressed from being electrically charged, adhesion of the processing residues to the lower cup  280  that might be caused by the static electricity can be suppressed, and, thus, deposition of the processing residues in the lower cup  280  can be suppressed. In order to suppress electrically charging of the lower cup  280  securely, the lower cup  280  may be grounded, as shown in  FIG. 10 , for example. 
     The bevel removing apparatus  61  includes a discharge pipe  290 , and the discharge pipe  290  guides the processing residues falling from the discharge opening  284  of the lower cup  280  downwards. Using the discharge pipe  290 , it is possible to guide the processing residues to a required position. The discharge pipe  290 , like the lower cup  280 , is formed of a conductive material, formed of an insulating material and coated with an anti-static agent, or formed of a mixture of an insulating material and an anti-static agent. Since the discharge pipe  290  can be suppressed from being electrically charged, adhesion of the processing residues to the discharge pipe  290  due to static electricity can be suppressed, and, therefore, it is possible to suppress accumulation of the processing residues inside the discharge pipe  290 . In order to suppress electrically charging of the discharge pipe  290  securely, the discharge pipe  290  may be grounded, as shown in  FIG. 10 , for example. 
     The bevel removing apparatus  61  includes a suction device  291 , and the suction device  291  sucks a gas inside the discharge pipe  290 . The suction device  291  is, for example, a vacuum pump. Instead of the vacuum pump, an ejector may be used. Since the suction device  291  sucks the gas inside the discharge pipe  290 , it is possible to drop the processing residues by a flow of the gas. As a result, the accumulation of the processing residues can be suppressed. The bevel removing apparatus  61  does not need to be equipped with the suction device  291  as long as the suction device  291  is connected to the bevel removing apparatus  61 . 
     The bevel removing apparatus  61  includes a suction box  292 , and the suction box  292  is provided at a portion of a suction path of the gas flowing from the discharge pipe  290  toward the suction device  291 . The suction device  291  sucks the inside of the suction box  292  from above. The inside of the suction box  292  is hermetically sealed, an exhaust line  293  is mounted to a ceiling of the suction box  292 , and the suction device  291  sucks the gas inside the discharge pipe  290  via the exhaust line  293  and the suction box  292 . Within the suction box  292 , the gas is light and is thus sucked upwards against gravity, whereas the processing residues are heavy and fall down due to the gravity. Since the gas and the processing residues can be separated, breakdown of the suction device  291  can be suppressed. 
     The bevel removing apparatus  61  includes a recovery box  294 , and the recovery box  294  collects the processing residues falling from the discharge pipe  290 . The recovery box  294  is disposed under the suction box  292 , for example. An extension pipe  295  guides the processing residues falling from the discharge pipe  290  into the recovery box  294 . The processing residues accumulated inside the recovery box  294  are regularly discarded. 
     The bevel removing apparatus  61  is equipped with a detector  296  configured to detect a failure in the fall of the processing residues. The detector  296  includes, for example, a weight sensor  297 , and the weight sensor  297  detects, for example, a change in the weight of the recovery box  294 . If the processing residues are accumulated during the fall, a weight increment of the recovery box  294  becomes small as compared to a processing amount. Here, an installation position of the weight sensor  297  is not particularly limited. By way of example, the weight sensor  297  may detect a change in the weight of the lower cup  280 . In this case, as the processing residues are deposited in the lower cup  280 , the weight of the lower cup  280  becomes heavy. 
     As the detector  296 , a non-illustrated imaging sensor may be used. The imaging sensor is provided inside at least one of the lower cup  280 , the discharge pipe  290 , the suction box  292 , the recovery box  294 , and the extension pipe  295  to image the inside thereof. If the processing residues are accumulated during the fall, these processing residues will be captured on an image by the imaging sensor. 
     Since the detector  296  sends the detection result to a controller of the bevel removing apparatus  61  and the controller detects the failure in the fall of the processing residues, a user may be urged to perform maintenance of the bevel removing apparatus  61 . For example, when the controller detects the failure in the fall of the processing residues, it sets off an alarm. The notification of the alarm is performed by an image or a sound. Further, the detection result of the weight sensor  297  may also be used to urge the user to dispose of the processing residues accumulated in the recovery box  294 . 
     As shown in  FIG. 8 , the bevel removing apparatus  61  includes an upper cover  300  and an upper cover moving mechanism  310 . The upper cover  300  is moved up and down between a closing position where it closes at least a part of an opening at an upper end of the lower cup  280  (see  FIG. 9B ) and an opening position where it opens the opening at the upper end of the lower cup  280  (see  FIG. 9A ). The upper cover moving mechanism  310  is, for example, a cylinder, and is configured to move the upper cover  300  up and down between the closing position and the opening position. Since the upper cover  300  is moved up and down between the closing position and the opening position, the carrying-in/carrying-out of the combined substrate  150  to/from the chuck  220  and the prevention of scattering of the processing residues from the combined substrate  150  can be both achieved. In addition, the upper cover moving mechanism  310  may be configured to move the upper cover  300  in the horizontal direction as well as in the vertical direction. 
     When the internal transfer mechanism  270  transfers the combined substrate  150  before being processed from the first storage table  250  onto the chuck  220 , the upper cover  300  stands by at the opening position. The internal transfer mechanism  270  passes through a gap between the upper cover  300  and the lower cup  280 , and hands the combined substrate  150  over to the chuck  220 , as shown in  FIG. 8 . Then, after the internal transfer mechanism  270  is retreated from the gap between the upper cover  300  and the lower cup  280 , the upper cover  300  is lowered from the opening position to the closing position. Then, while the processing unit  330  is processing the combined substrate  150  with the blade  160 , the upper cover  300  suppresses the scattering of the processing residues at the closing position. Upon the completion of the processing of the combined substrate  150 , the upper cover  300  is raised from the closing position to the opening position. Thereafter, the internal transfer mechanism  270  passes through the gap between the upper cover  300  and the lower cup  280 , receives the processed combined substrate  150  from the chuck  220 , and transfers it onto the second storage table  260 . 
     As shown in  FIG. 8 , the position where the combined substrate  150  is stored on the second storage table  260  may be lower than the opening position of the upper cover  300 . As compared to a case where the positional relationship is the reverse, the bevel removing apparatus  61  can be downsized. If the positional relationship is the reverse, the combined substrate  150  passes through the gap between the upper cover  300  and the second storage table  260  and rises higher than the upper cover  300  and the second storage table  260 . To enable this rise of the combined substrate  150 , a distance between the upper cover  300  and the second storage table  260  in the horizontal direction becomes larger than the diameter of the combined substrate  150 . According to the present exemplary embodiment, however, the distance between the upper cover  300  and the second storage table  260  in the horizontal direction can be shortened, and the bevel removing apparatus  61  can be downsized. 
     The upper cover  300  has an upper cylindrical member  301  surrounding the outer periphery of the combined substrate  150  held by the chuck  220 , as illustrated in  FIG. 9B . Even when the lower cylindrical member  281  of the lower cup  280  is disposed below the combined substrate  150 , the upper cylindrical member  301  of the upper cover  300  can suppress the scattering of the processing residues from the combined substrate  150  in a transversal direction. The upper cylindrical member  301  is formed in, for example, a cylindrical shape, and has a diameter larger than that of the combined substrate  150 . The upper cylindrical member  301  may have a groove  302  to avoid interference between the upper cylindrical member  301  and the processing unit  330 . Since the diameter of the upper cylindrical member  301  can be reduced, the upper cover  300  can be downsized. For example, the blade  160  and a blade mounting unit  331  may be disposed in the groove  302 . 
     The upper cover  300  has a ceiling member  303  that covers at least the outer periphery of the combined substrate  150  held by the chuck  220  from above. The ceiling member  303  is formed in, for example, a ring shape. An outer diameter of the ceiling member  303  is larger than the diameter of the combined substrate  150 , and an inner diameter of the ceiling member  303  is smaller than the diameter of the combined substrate  150 . Alternatively, the ceiling member  303  may be formed in a disk shape, and may cover the entire combined substrate  150  from above. Since the ceiling member  303  covers at least the outer periphery of the combined substrate  150  from above, it is possible to suppress the scattering of the processing residues from the combined substrate  150  in an upward direction. 
       FIG. 11  is a cross sectional view illustrating an example of a gas flow formed around the outer periphery of the combined substrate during the processing. Since the suction device  291  sucks the gas inside the discharge pipe  290  as described above, the gas inside the lower cup  280  is also sucked. As a result, since the inside of the lower cup  280  is turned into a negative pressure, the gas flows from an opening of the ring-shaped ceiling member  303  into the lower cup  280 . The gas flows into the lower cup  280  through a gap formed between the ceiling member  303  and the combined substrate  150 . Since the gas forms a diametrically outward flow on a top surface of the combined substrate  150 , the processing residues can be dropped from the combined substrate  150  into the lower cup  280  owing to the gas flow. Thus, the adhesion of the processing residues to the top surface of the combined substrate  150  can be suppressed. 
     Near the combined substrate  150 , a gas flow is also formed due to the rotation of the combined substrate  150 . The gas flows outwards in the diametrical direction by a centrifugal force while being drawn to and rotated along the combined substrate  150 . 
     The ceiling member  303  has a ring-shaped first horizontal member  304  forming a gap with respect to the combined substrate  150 ; and a ring-shaped second horizontal member  305  forming a gap smaller than the gap formed by the first horizontal member  304  at an inner side than the first horizontal member  304 . By narrowing the gas flow by the second horizontal member  305 , it is possible to increase a flow velocity of the gas in the same principle as in a venturi tube, so that the gas flow can be strengthened. 
     The ceiling member  303  may have a ring-shaped first inclined portion  306  which connects the first horizontal member  304  and the second horizontal member  305 . The first inclined portion  306  is inclined upwards as it goes outwards in the diametrical direction. The first horizontal member  304  may be disposed directly above the outer periphery of the combined substrate  150 . Further, the ceiling member  303  may have a ring-shaped second inclined portion  307  which connects the second horizontal member  305  and the upper cylindrical member  301 . The second inclined portion  307  is inclined downwards as it goes outwards in the diametrical direction. 
     The bevel removing apparatus  61  may have an upper nozzle  308 , which is configured to discharge a gas toward the combined substrate  150  from above in order to form a gas flow flowing outwards in the diametrical direction from the outer periphery of the combined substrate  150  held by the chuck  220 . Since the gas forms such a diametrically outward flow on the top surface of the combined substrate  150 , the processing residues can be dropped from the combined substrate  150  into the lower cup  280  due to this gas flow. Thus, the adhesion of the processing residues to the top surface of the combined substrate  150  can be suppressed. The upper nozzle  308  is formed in, for example, a ring shape, and forms the gas flow over the entire outer periphery of the combined substrate  150 . The upper nozzle  308  may be moved together with the upper cover  300  in order to suppress the interference between the upper nozzle  308  and the internal transfer mechanism  270 . 
     The bevel removing apparatus  61  may have a lower nozzle  309 , which is configured to discharge a gas toward the combined substrate  150  from below in order to form a gas flow flowing outwards in the diametrical direction from the outer periphery of the combined substrate  150  held by the chuck  220 . A substrate holding surface  221  of the chuck  220  is smaller than the diameter of the combined substrate  150 , and a bottom surface of the combined substrate  150  projects diametrically outwards from the chuck  220  over the entire circumference thereof. The lower nozzle  309  discharges the gas toward the projecting portion of the combined substrate  150  from diagonally below. Since the gas forms a diametrically outward flow on the bottom surface of the combined substrate  150 , the adhesion of the processing residues to the bottom surface of the combined substrate  150  can be suppressed. The lower nozzle  309  is formed in, for example, a ring shape, and forms the gas flow over the entire outer periphery of the combined substrate  150 . 
     The lower nozzle  309  is provided at, for example, the cylindrical member  241  of the protective cup  240 , and a gas path, which is directed upwards as it goes outwards in the diametrical direction, is formed between the lower nozzle  309  and an inclined surface  222  of the chuck  220 . The gas is supplied from a gas supply  311  into the cylindrical member  241 , and the inside of the cylindrical member  241  is turned into a positive pressure. The gas in the cylindrical member  241  is discharged by the lower nozzle  309 . Thus, the processing residues can be suppressed from entering the cylindrical member  241 , so that breakdown of the rotating mechanism  230  disposed inside the cylindrical member  241  can be suppressed. In addition, the protective cup  240  is disposed inside the lower cup  280 , as shown to  FIG. 9A  and  FIG. 9B . The lower cup  280  and the protective cup  240  may be supported by the same supporting column  211 . 
     As shown in  FIG. 8 , the bevel removing apparatus  61  includes an imaging sensor  320  configured to image the outer periphery of the combined substrate  150  (more specifically, the processing target substrate  100 ) held by the chuck  220 . Further, as shown in  FIG. 7 , the bevel removing apparatus  61  is equipped with an imaging sensor moving mechanism  321  configured to move the imaging sensor  320  between an imaging position and a standby position. The imaging position is a position where the imaging sensor  320  images the outer periphery of the combined substrate  150  between the upper cover  300  and the lower cup  280 . The standby position is a position where the imaging sensor  320  stays out of an elevation range of the upper cover  300 . According to the present exemplary embodiment, the processing of the combined substrate  150  and the imaging of the combined substrate  150  can be performed in the state that the combined substrate  150  is held by the same chuck  220 . As compared to a case where a chuck for the processing and a chuck for the imaging are provided separately, the number of times of the transfer of the combined substrate  150  can be reduced, and the position deviation of the combined substrate  150  that might be caused by the transfer can be suppressed. 
     While the processing unit  330  is processing the combined substrate  150  with the blade  160 , the upper cover  300  suppresses the scattering of the processing residues at the closing position. Since the imaging sensor  320  stands by at the standby position when the combined substrate  150  is processed, the scattering of the processing residues to the imaging sensor  320  can be suppressed, so that breakdown of the imaging sensor  320  can be suppressed. Upon the completion of the processing of the combined substrate  150 , the upper cover  300  is raised from the closing position to the opening position. Thereafter, the imaging sensor moving mechanism  321  moves the imaging sensor  320  from the standby position to the imaging position, and the imaging sensor  320  images the outer periphery  103  of the processing target substrate  100 . In the meantime, the rotating mechanism  230  rotates the processing target substrate  100 , and the imaging sensor  320  images the entire outer periphery  103  of the processing target substrate  100 . When the imaging is finished, the imaging sensor moving mechanism  321  moves the imaging sensor  320  from the imaging position to the standby position. Subsequently, the internal transfer mechanism  270  passes through the gap between the upper cover  300  and the lower cup  280 , receives the processed combined substrate  150  from the chuck  220 , and transfers it onto the second storage table  260 . 
       FIG. 12  is a functional block diagram illustrating constituent components of a controller according to the exemplary embodiment. Individual functional blocks shown in  FIG. 12  are conceptual and may not necessarily be physically configured exactly the same as shown in  FIG. 12 . All or a part of the functional blocks may be functionally or physically dispersed or combined on a unit. All or a part of processing functions performed in the respective functional blocks may be implemented by a program executed by the CPU or implemented by hardware through a wired logic. A controller  500  is implemented by a computer as a part of the bevel removing apparatus  61 , the same as the control device  9 . Further, the control device  9  may have the function of the controller  500 . 
     The controller  500  is equipped with a correction unit  501  configured to calculate a deviation between a rotation center of the chuck  220  and the center of the combined substrate  150  by image-processing the image captured by the imaging sensor  320 , and to correct a path through which the internal transfer mechanism  270  transfers the combined substrate  150  such that the deviation is reduced next time. By way of example, the center of the combined substrate  150  is calculated as a center of a circle passing through three points on the outer periphery  103  of the processing target substrate  100  measured by the image-processing. The path corrected by the correction unit  501  is a path through which the combined substrate  150  is transferred from the first storage table  250  to the chuck  220 . 
     The correction unit  501  corrects at least one of a start point or an end point of the path. The start point of the path is a position where the holder  272  of the internal transfer mechanism  270  receives the combined substrate  150  from the first storage table  250 , that is, a position where the holder  272  holds the combined substrate  150 . The end point of the path is a position where the holder  272  of the internal transfer mechanism  270  hands the combined substrate  150  over to the chuck  220 , that is, a position where the combined substrate  150  is separated from the holder  272 . 
     Since the correction unit  501  corrects at least one of the start point or the end point of the path, the deviation between the rotation center of the chuck  220  and the center of the combined substrate  150  can be reduced. When the chuck  220  is rotated, it is possible to suppress the combined substrate  150  from being shaken to be deviated. If the combined substrate  150  is shaken to be deviated, the insertion depth of the blade  160  varies depending on the position of the combined substrate  150  in the circumferential direction. The insertion depth of the blade  160  is an insertion depth into the gap between the processing target substrate  100  and the support substrate  130 . If the insertion depth of the blade  160  is too large, a load applied to the blade  160  is too large, resulting in a failure such as deformation of the blade  160 . If the insertion depth of the blade  160  is too small, on the other hand, a load applied to the combined substrate  150  is too small, resulting in a failure to remove the bevel  104 . According to the present exemplary embodiment, since the correction unit  501  can suppress the deviation of the combined substrate  150 , these problems can be avoided. 
     Further, the controller  500  may be equipped with an instruction transmitting unit  504  configured to image-process the image captured by the imaging sensor  320 , calculate the deviation between the rotation center of the chuck  220  and the center of the combined substrate  150 , and send an instruction to at least one of the first transfer device  51  or the second transfer devices  63 . The instruction transmitting unit  504  sends the first transfer device  51  an instruction for correcting a position where the first transfer device  51  hands the combined substrate  150  before being processed over to the first storage table  250  such that the deviation is reduced next time. Further, the instruction transmitting unit  504  further calculates a position deviation of the combined substrate  150  on the second storage table  260  from the deviation between the rotation center of the chuck  220  and the center of the combined substrate  150 , and sends the second transfer device  63  an instruction for correcting a position where the second transfer device  63  receives the combined substrate  150  after being processed from the second storage table  260 . The second transfer device  63  can maintain a required position of the combined substrate  150  after being processed. 
     In addition, the controller  500  includes a determination unit  502  configured to image-process the image captured by the imaging sensor  320  and determine whether or not the processing result of the combined substrate  150  is good or bad. The determination unit  502  calculates a position of the outer periphery  103  of the processing target substrate  100  after being processed through the image processing, and determines whether the diameter of the processing target substrate  100  is reduced such that the entire outer periphery  103  of the processing target substrate  100  reaches the first division surface D 1 . If the diameter of the processing target substrate  100  is found to be reduced such that the entire outer periphery  103  of the processing target substrate  100  reaches the first division surface D 1 , a determination that the processing result is good is made. On the other hand, if at least a part of the outer periphery  103  of the processing target substrate  100  does not reach the first division surface D 1 , there is made a determination that the processing result is bad. The combined substrate  150  having the poor processing result may be processed again in the bevel removing apparatus  61  after changing a processing condition (for example, a load of the blade  160  in the processing) before being transferred to the thinning apparatus  62 , or may not be transferred to the thinning apparatus  62  but be returned to the cassette CS on the placing member  21 . 
       FIG. 13  is an enlarged view of the processing unit shown in  FIG. 9B . The bevel removing apparatus  61  is equipped with the processing unit  330  configured to process the combined substrate  150  (more specifically, the processing target substrate  100 ) by pressing the horizontal blade  160  against the outer periphery of the combined substrate  150 . The blade  160  is pressed against the outer periphery of the combined substrate  150  and passively rotated along with the rotation of the combined substrate  150 . The rotational direction of the blade  160  is opposite to the rotational direction of the combined substrate  150 , and since the rotational speed of the outer periphery of the blade  160  and the rotational speed of the outer periphery of the combined substrate  150  are the same, damage to the combined substrate  150  and the blade  160  can be suppressed. Alternatively, the blade  160  may be rotated independently of the combined substrate  150 . 
     The blade  160  includes, as shown in  FIG. 5 , for example, a horizontal lower disk member  161 , a wedge-shaped blade member  162 , and a horizontal upper disk member  163  in this order from the lower side toward the upper side. The blade portion  162  protrudes diametrically outwards from both of the lower disk member  161  and the upper disk member  163 , and includes a horizontal surface  164  and an inclined surface  165  at a leading end thereof. The inclined surface  165  slopes downwards as it goes outwards in the diametrical direction. The horizontal surface  164  of the blade member  162  is in contact with a top surface of the support substrate  130 , and the inclined surface  165  of the blade member  162  pushes a to-be-removed portion (for example, the fragments  107 ) of the processing target substrate  100  upwards. Since the blade  160  is a consumable, it is replaced appropriately. 
     The processing unit  330  has a blade mounting unit  331  to which the blade  160  is mounted, as shown in  FIG. 13 . The blade mounting unit  331  has a horizontal mounting surface  332 , and this mounting surface  332  is provided with a plurality of bolt holes formed at a certain distance therebetween. A bolt  333  is inserted into each of the plurality of bolt holes, and the blade  160  is mounted to the blade mounting unit  331  by the bolts  333  in a replaceable manner. A non-illustrated magnet may be used instead of the bolt  333 . The magnet may be either a permanent magnet or an electromagnet. 
     The blade  160  has a flat surface  166  in contact with the mounting surface  332  of the processing unit  330 . The flat surface  166  is formed in a recess  167  on a bottom surface of the blade  160 , for example. The flat surface  166  and the horizontal surface  164  (see  FIG. 5 ) are parallel to each other, and they have a required height difference, or are disposed on the same plane. Either way, the height of the horizontal surface  164  and the horizontality of the horizontal surface  164  can be maintained before and after the replacement of the blade  160 . 
     The processing unit  330  has a driving unit  340  configured to move the blade mounting unit  331  back and forth in directions in which the blade mounting unit  331  is connected to or disconnected from the chuck  220 . By moving back and forth the blade  160 , which is lighter than the chuck  220 , instead of moving the chuck  220  back and forth, a driving force required for connecting or disconnecting the blade  160  and the combined substrate  150  can be reduced. 
     The driving unit  340  includes, for example, a rotary motor  341  and a ball screw  342  configured to convert a rotary motion of the rotary motor  341  into a linear motion. The ball screw  342  includes a screw shaft  343  and a screw nut  344 . The screw shaft  343  is connected to an output shaft of the rotary motor  341  via a coupling  345 , for example, and is rotated along the output shaft. Meanwhile, the screw nut  344  is made to move back and forth by the rotation of the screw shaft  343 , and, as a result, the blade mounting unit  331  is moved back and forth. 
     The processing unit  330  includes a first slider  351  configured to be moved back and forth by the driving unit  340 , a second slider  352  configured to be moved back and forth along with the first slider  351 , and an elastic body  353  connecting the first slider  351  and the second slider  352 . By way of non-limiting example, a coil spring is used as the elastic body  353 . The screw nut  344  is provided to the first slider  351 , and the blade mounting unit  331  is provided to the second slider  352 . The blade mounting unit  331  is moved back and forth along with the second slider  352 . The second slider  352  is disposed in front of the first slider  351 . 
     If the combined substrate  150  before being processed is held by the chuck  220 , the first slider  351  advances from a standby position to a processing position, and the second slider  352  is moved forwards via the elastic body  353 , pressing the blade  160  against the combined substrate  150 . If the processing position of the first slider  351  is located further forward, a distance between the first slider  351  and the second slider  352  becomes shorter, and an elastic restoring force of the elastic body  353  becomes stronger, so that the load of the blade  160  is increased. During the processing, the first slider  351  is stopped at the processing position. 
     Upon the completion of the processing, the first slider  351  is returned from the processing position to the standby position, and the second slider  352  is retreated via the elastic body  353 , separating the blade  160  from the combined substrate  150 . 
     However, if the rotation center of the chuck  220  and the center of the combined substrate  150  are deviated and eccentricity occurs, the combined substrate  150  is shaken to be deviated when the chuck  220  is rotated. The elastic body  353  elastically deforms in an advancing/retreating direction of the blade  160  in order to move the blade  160  back and forth to absorb the deviation of the combined substrate  150 . According to the present exemplary embodiment, since the elastic body  353  absorbs the deviation of the combined substrate  150 , the above-mentioned problem caused by the deviation can be solved. 
     In addition, in the absence of the elastic body  353 , not only the screw nut  344  but also the blade mounting unit  331  is provided to the first slider  351 . In this case, a processing controller  503  shown in  FIG. 12  may adjust the processing position of the first slider  351  forwards and backwards to move the blade  160  back and forth so as to absorb the deviation of the combined substrate  150  caused by the eccentricity. However, when the elastic body  353  is present, it is possible to absorb the deviation of the combined substrate  150  in the state that the processing position of the first slider  351  fixed. Thus, the control by the processing controller  503  can be eased. 
     The processing unit  330  has a rotation supporting mechanism  360  configured to support the blade mounting unit  331  rotatably. The rotation supporting mechanism  360  has a rotation shaft  361 , a bearing box  362 , and a bearing Br. The blade mounting unit  331  is fixed to the bearing box  362  via the vertical rotation shaft  361 . The bearing box  362  has a cylindrical member  363  which holds an outer ring of the bearing Br; and a lid  364  which closes an opening at an upper end of the cylindrical member  363 . The rotation shaft  361  is fixed to the lid  364 . A height adjustment shaft  371  is vertically disposed on an extension line of the rotation shaft  361 , and the height adjustment shaft  371  holds an inner ring of the bearing Br. The blade mounting unit  331  is rotatably supported by the bearing Br. 
     The processing unit  330  has a height adjusting mechanism  370  configured to adjust the height of the mounting surface  332  of the blade mounting unit  331  with respect to the substrate holding surface  221  of the chuck  220 . The height adjusting mechanism  370  includes, for example, the height adjustment shaft  371  and a height adjustment base  372 . The height adjustment shaft  371  has a screw shaft  373 , and the screw shaft  373  is inserted into a screw hole, which is formed at the height adjustment base  372 . By rotating the height adjustment shaft  371 , the height adjustment shaft  371  can be moved up and down to adjust the height of the mounting surface  332  of the blade mounting unit  331 . The height adjustment base  372  is fixed to the second slider  352 , and the blade mounting unit  331  is provided to the second slider  352  with the height adjusting mechanism  370  and the rotation supporting mechanism  360  therebetween. 
     Here, the configuration of the height adjusting mechanism  370  is not particularly limited. For example, the height adjusting mechanism  370  may have an actuator configured to move the height adjustment shaft  371  up and down. As such an actuator, a piezo element or the like may be used. The height adjustment shaft  371  can be moved up and down automatically by the actuator. The actuator is mounted to the height adjustment base  372 . 
     The processing unit  330  has a rotation restricting mechanism  380  configured to restrict the rotation of the blade mounting unit  331 . The rotation restricting mechanism  380  has a stopper pin  381 ; and a pin hole  382  into which the stopper pin  381  is fitted. The pin hole  382  is formed on an outer peripheral surface of the cylindrical member  363  of the bearing box  362 , and is moved back and forth along with the bearing box  362 . If the driving unit  340  moves the bearing box  362  backwards and the stopper pin  381  is fitted into the pin hole  382 , the rotation of the bearing box  362  is restricted, and, as a result, the rotation of the blade mounting unit  331  is restricted. Since the blade  160  can be replaced in this state, the replacement of the blade  160  can be carried out easily. 
     Since the pin hole  382  is rotated along with the bearing box  362 , it may be deviated from an extension line of the stopper pin  381  when the rotation of the bearing box  362  is stopped. In this state, if the driving unit  340  retreats the bearing box  362 , the bearing box  362  comes into contact with a front end of the stopper pin  381 . The stopper pin  381  can be moved in an advancing/retreating direction of the bearing box  362 , and a force is applied by an elastic body  383  such as a coil spring toward an advanced position. If the stopper pin  381  is pushed backwards by the bearing box  362 , the elastic body  383  elastically deforms to allow the stopper pin  381  to retreat. Thereafter, if the pin hole  382  is placed on the extension line of the stopper pin  381  by rotating the bearing box  362 , the stopper pin  381  is pushed back to the advanced position by an elastic restoring force of the elastic body  383  and fitted into the pin hole  382 . 
     The processing unit  330  is equipped with a parallelism adjusting mechanism  390  configured to adjust the parallelism of the mounting surface  332  of the blade mounting unit  331  with respect to the substrate holding surface  221  of the chuck  220 , as shown in  FIG. 9A  and  FIG. 9B . The parallelism adjusting mechanism  390  includes a plurality of (for example, three) height adjusters  392  configured to adjust the heights of different portions of a base plate  391 , as shown in  FIG. 7 . 
     A guide rail Gd is fixed to the base plate  391 , and the guide rail Gd guides the first slider  351  and the second slider  352 . The blade mounting unit  331  is installed to the base plate  391  with the guide rail Gd, the second slider  352 , and so forth therebetween. 
     The height adjusters  392  are respectively mounted to upper ends of a plurality of (for example, three) supporting columns  212 , and lower ends of the supporting columns  212  are mounted to the base  210 . By adjusting the heights of three points of the base plate  391 , the parallelism of the mounting surface  332  of the blade mounting unit  331  can be adjusted. 
     The height adjuster  392  is a so-called leveling bolt, and has, for example, a screw nut  393 , a screw shaft  394 , and a fastening bolt  395 . The screw nut  393  is fixed to the base plate  391 . The screw shaft  394  is inserted into a screw hole of the screw nut  393  and into a through hole of the base plate  391  to come into contact with an upper end surface of the supporting column  212  rotatably. A screw hole is formed in the upper end surface of the supporting column  212 , and the fastening bolt  395  is inserted into this screw hole. The fastening bolt  395  penetrates the inside of the cylindrical screw shaft  394  and is inserted into the screw hole of supporting column  212 . The screw hole of the supporting column  212  has an outer diameter smaller than an inner diameter of the cylindrical screw shaft  394 , and the screw shaft  394  is in contact with the upper end surface of the supporting column  212  rotatably. 
     When adjusting the height of each point of the base plate  391 , the fastening bolt  395  is first loosened, and, then, the screw shaft  394  is rotated to move the screw nut  393  up and down. Thereafter, if the fastening bolt  395  is tightened, the height can be fixed. 
     Here, the height adjuster  392  may have an actuator instead of the leveling bolt. As the actuator, a piezo element or the like may be used, for example. The height of each point of the base plate  391  can be adjusted automatically by the actuator. 
     Moreover, since the parallelism adjusting mechanism  390  has the height adjusters  392 , they may also be used as the height adjusting mechanism  370 . However, the parallelism adjusting mechanism  390  may be provided separately from the height adjusting mechanism  370 . The height adjusting mechanism  370  adjusts the height of the mounting surface  332  of the blade mounting unit  331  with respect to the substrate holding surface  221  of the chuck  220  while maintaining the parallelism adjusted by the parallelism adjusting mechanism  390 . Thus, if the height adjusting mechanism  370  and the parallelism adjusting mechanism  390  are separately provided, the number of times of the adjustment of the parallelism, which features a high level of difficulty, can be reduced. 
     The processing unit  330  may additionally have a processing cover  354  configured to be moved back and forth along with the second slider  352 , as shown in  FIG. 13 . The processing cover  354  has, for example, a front plate  355 , a top plate  356 , and a pair of left and right side plates  357 . The front plate  355  is vertically disposed and faces the cylindrical member  241  of the protective cup  240 . The top plate  356  has a through hole through which the rotation shaft  361  is inserted. The processing cover  354  has a cylindrical member  358  extending upwards from an edge of the through hole of the top plate  356 . The cylindrical member  358  is disposed inside a skirt member  334  of the blade mounting unit  331 , and a labyrinth structure is formed between the cylindrical member  358  and the skirt member  334 . The processing cover  354  accommodates therein the rotation supporting mechanism  360  and at least a part of the height adjusting mechanism  370 , and serves to suppress scattering of processing residues to the rotation supporting mechanism  360  and the height adjusting mechanism  370 . 
     The processing unit  330  may have a partition  396  extending upwards from a front end of the base plate  391  to partition the inside of the processing cover  354 , as shown in  FIG. 13 . The partition  396  is vertically disposed behind the front plate  355  of the processing cover  354  and in front of the guide rail Gd, and a labyrinth structure is formed between the partition  396  and the front plate  355 . The partition  396  serves to suppress the scattering of processing residues to the rotation supporting mechanism  360 , the height adjusting mechanism  370 , and the guide rail Gd in cooperation with the front plate  355  of the processing cover  354 . 
       FIG. 14A  is a plan view showing a pressing device according to the exemplary embodiment.  FIG. 14B  is a cross-sectional view taken along a line XIVB-XIVB of  FIG. 14A . As illustrated in  FIG. 14A  and  FIG. 14B , the bevel removing apparatus  61  may be equipped with a pressing device  400 . The pressing device  400  presses the fragment  107 , which is to be pushed up from the processing target substrate  100  by the blade  160 , from above while maintaining a certain distance from the blade  160  in the circumferential direction of the processing target substrate  100 . The fragment  107  is of a circular arc shape when viewed from a top surface thereof which is divided along the first division surface D 1  and the second division surface D 2 . The fragment  107  includes the bevel  104 . As illustrated in  FIG. 14B , the pressing device  400  presses a portion of the processing target substrate  100  at the rear of the blade  160  in the rotational direction. The fragment  107  can be pushed up at a sharp angle by the pressing device  400 , and the division along the second division surface D 2  can be accelerated. 
     The pressing device  400  has, for example, a ball  401  pressed onto the fragment  107 , and a support  402  configured to support the ball  401  rotatably. Since the ball  401  is in contact with the fragment  107  on a spherical surface, frictional resistance between the ball  401  and the fragment  107  can be reduced. In addition, since the support  402  rotatably supports the ball  401 , the frictional resistance between the ball  401  and the fragment  107  can be further reduced. 
     The pressing device  400  may be fixed to the upper cover  300 , and may be moved up and down along with the upper cover  300 . When the upper cover  300  descends to the closing position, the pressing device  400  is pressed against the fragment  107 . The pressing device  400  may be fixed to the upper cover  300  with an elastic body such as a coil spring therebetween. The elastic body presses the pressing device  400  against the fragment  107  by its elastic restoring force. 
       FIG. 15  is a plan view showing an example of a range of the outer periphery of the combined substrate in contact with the blade. The controller  500  includes, as shown in  FIG. 12 , the processing controller  503  configured to control the rotating mechanism  230  of the chuck  220  and the processing unit  330 . As shown in  FIG. 15 , the processing controller  503  moves the blade  160  back and forth so that a part (for example, the second division surface D 2 ) of the outer periphery of the combined substrate  150  does not come into contact with the blade  160  while the combined substrate  150  is being rotated along with the chuck  220 . In  FIG. 15 , SP indicates a contact start point at which the blade  160  starts to come into contact with the outer periphery of the combined substrate  150 , and EP refers to a contact end point at which the blade  160  starts to separate from the outer periphery of the combined substrate  150 . The second division surface D 2  is disposed between the contact start point SP and the contact end point EP. 
     If the combined substrate  150  before being processed is held by the chuck  220 , the imaging sensor moving mechanism  321  moves the imaging sensor  320  from the standby position to the imaging position before the first slider  351  advances from the standby position to the processing position, and the imaging sensor  320  images a notch  108  of the processing target substrate  100 . The notch  108  indicates a crystal orientation of the processing target substrate  100  and is formed at the outer periphery  103  of the processing target substrate  100 . Instead of the notch  108 , an orientation flat may be formed at the outer periphery  103  of the processing target substrate  100 . When the imaging of the notch  108  is finished, the imaging sensor moving mechanism  321  moves the imaging sensor  320  from the imaging position to the standby position. 
     The processing controller  503  image-processes the image of the notch  108  captured by the imaging sensor  320 , and measures a position of the notch  108 . A relationship between the position of the notch  108  and a position of the second division surface D 2  is previously stored in a recording medium. The processing controller  503  detects the position of the second division surface D 2  from the measured position of the notch  108  based on the relation previously stored in the recording medium. 
     The processing controller  503  moves the blade  160  back and forth to avoid the position of the second division surface D 2  when the blade  160  is pressed against the outer periphery of the processing target substrate  100  while the processing target substrate  100  is being rotated. For example, if the blade  160  comes into contact with the second division surface D 2 , an impact is generated at that timing because the second modification layer M 2  is formed on the second division surface D 2 . If the impact is large, the following problem may be caused. An unintended crack may be formed, and the fragment  107  may fall down from an unexpected position. Neighboring fragments  107  may fall without being divided along the second division surface D 2 , and pile up together. As a result, the lifetime of the blade  160  may be reduced. According to the present exemplary embodiment, since the processing controller  503  moves the blade  160  back and forth to avoid the position of the second division surface D 2 , this problem can be solved. 
       FIG. 16  is a cross sectional view showing a state in which the horizontality is measured by a measuring device according to the exemplary embodiment.  FIG. 17  is a cross sectional view showing a state in which the height is measured by a measuring device according to the exemplary embodiment. As shown in  FIG. 16  and  FIG. 17 , the processing unit  330  includes a measuring device mounting unit to which a measuring device  410  is mounted. The blade mounting unit  331  is used as the measuring device mounting unit, and the measuring device  410  and the blade  160  are mounted interchangeably to the same mounting surface  332  of the blade mounting unit  331  by using the bolt  333  or the like. Instead of the bolt  333 , a magnet may be used as mentioned above. As compared to a case where the measuring device mounting unit and the blade mounting unit  331  are separately provided, the processing unit  330  can be downsized. 
     The measuring device  410  is configured to measure at least one (both in the present exemplary embodiment) of the parallelism or the height of the mounting surface  332  of the blade  160  with respect to the substrate holding surface  221  of the chuck  220 . As compared to a case of measuring the parallelism or the height with eyes without using the measuring device  410 , the parallelism or the height can be precisely adjusted regardless of a skill level of an operator, so that the blade  160  can be properly and easily mounted. 
     The measuring device  410  includes, for example, a revolving arm  411  mounted on the mounting surface  332  of the blade mounting unit  331 ; and a height sensor  412  mounted to one end of the revolving arm  411 . The height sensor  412  is configured to measure the height of the substrate holding surface  221  of the chuck  220 . Although the height sensor  412  is of a contact type in the present exemplary embodiment, a non-contact type may be used instead. 
     The rotation supporting mechanism  360  rotatably supports the blade mounting unit  331  as described above. If the blade mounting unit  331  is rotated, the revolving arm  411  can be rotated, so that a height distribution of the substrate holding surface  221  of the chuck  220  with respect to the mounting surface  332  of the blade mounting unit  331  can be measured, and the parallelism can be calculated from the measured height distribution. If the mounting surface  332  becomes completely parallel to the substrate holding surface  221 , a measurement value of the height sensor  412  does not change even if a rotation angle of the blade mounting unit  331  is changed. 
     As described above, the driving unit  340  moves the blade mounting unit  331  back and forth in the direction in which the blade mounting unit  331  is connected to or disconnected from the chuck  220 . If the blade mounting unit  331  is moved back and forth, the revolving arm  411  can be moved back and forth, so that the height distribution of the substrate holding surface  221  of the chuck  220  with respect to the mounting surface  332  of the blade mounting unit  331  can be measured, and the parallelism can be calculated from the height distribution. If the mounting surface  332  becomes completely parallel to the substrate holding surface  221 , the measurement value of the height sensor  412  does not change even if the blade mounting unit  331  is moved back and forth. 
     Based on the measurement result of the measuring device  410 , the operator adjusts the parallelism of the blade mounting unit  331  with respect to the substrate holding surface  221  of the chuck  220  by using the parallelism adjusting mechanism  390  so that the parallelism falls within a predetermined tolerance range. The adjustment of the parallelism may be performed in the state that the measuring device  410  is mounted to the blade mounting unit  331 . The adjustment of the parallelism and the measurement of the parallelism may be repeatedly performed until the degree of the parallelism falls within the predetermined tolerance range. 
     After the adjustment of the parallelism, the measurement of the height may be performed. Although the height sensor  412  may be used for the height measurement, a block gauge  413  may be used in the present exemplary embodiment. The block gauge  413  is mounted to the other end of the revolving arm  411 . The block gauge  413  has a step-shaped portion  414 . 
     Since the height sensor  412  and the block gauge  413  are mounted to the one and the same revolving arm  411 , the operator reverses the blade mounting unit  331  from the state shown in  FIG. 16  to the state shown in  FIG. 17  after the parallelism is adjusted, thus allowing the block gauge  413  to be oriented toward the chuck  220 . Based on whether or not the height of the substrate holding surface  221  of the chuck  220  is within the range of the step-shaped portion  414  of the block gauge  413 , it can be confirmed whether or not the height of the mounting surface  332  of the blade mounting unit  331  is within the predetermined tolerance range. This confirmation may be performed with the eyes of the operator. When the height of the substrate holding surface  221  is not within the range of the step-shaped portion  414 , the operator adjusts the height by using the height adjusting mechanism  370  until it comes within the range. The adjustment of the height is performed in the state that the measuring device  410  is mounted to the blade mounting unit  331 . 
     After the adjustment of the height, the rotation restricting mechanism  380  restricts the rotation of the blade mounting unit  331 . Then, the measuring device  410  is separated, and the blade  160  is mounted instead. Since this operation is performed in the state that the rotation of the blade mounting unit  331  is restricted, the exchange between the measuring device  410  and the blade  160  is carried out easily. 
     In addition, the height sensor  412  and the block gauge  413  may be mounted to the blade mounting unit  331  interchangeably. Furthermore, the block gauge  413  may not be mounted to the blade mounting unit  331  but be installed on the substrate holding surface  221  of the chuck  220 , and whether or not the height of the mounting surface  332  of the blade mounting unit  331  is within the range of the step-shaped portion  414  of the block gauge  413  may be observed with the eyes. 
     So far, the exemplary embodiment of the substrate processing apparatus and the substrate processing method according to the present disclosure have been described. However, the present disclosure is not limited to the above-described exemplary embodiment or the like. Various changes, corrections, replacements, addition, deletion and combinations may be made within the scope of the claims, and all of these are included in the scope of the inventive concept of the present disclosure. 
     In the above-described exemplary embodiment, the bevel removing apparatus  61  is used as the substrate processing apparatus. However, the substrate processing apparatus only needs to process the substrate by pressing the horizontal blade  160  on the outer periphery of the substrate, and the use of the substrate processing apparatus is not limited to removing the bevel  104 . 
     By way of example, in the substrate processing apparatus, the blade  160  may be inserted between the processing target substrate  100  and the support substrate  130  before the bevel removing and the thinning shown in  FIG. 18  to extend the first crack C 1  or both the first crack C 1  and the third crack C 3 . Prior to the thinning, it is possible to form a crack that serves as a starting point of the bevel removing or the bevel removing and the thinning. That is, the substrate processing apparatus may be configured to form the crack serving as a starting point before performing the bevel removing and the thinning of the processing target substrate  100  simultaneously. In this case as well, dust generated during the formation of the crack can be reliably collected by the lower cup  280 , so that the bevel removing apparatus  61  and the combined substrate  150  can be maintained clean. 
       FIG. 18  is a cross sectional view illustrating a modification example of the bevel removing and the thinning shown in  FIG. 6 . In this modification example shown in  FIG. 18 , the first crack C 1  and the third crack C 3  are extended by applying an external force to the processing target substrate  100 . The first modification layer M 1  is formed so that the first crack C 1  does reach the first main surface  101  and does not reach the second main surface  102  before the thinning shown by a broken line in  FIG. 18 . The third modification layer M 3  is formed so that the third crack C 3  intersects with the first division surface D 1  and does not reach the outer periphery  103 . The formation of the first modification layer M 1  and the third modification layer M 3  is performed by the laser processing apparatus  41 . However, the second modification layer M 2  is not formed here. Then, in the thinning apparatus  62  as shown in  FIG. 6 , bevel removal and thinning are performed at the same time, as shown in  FIG. 18 . 
     Furthermore, the substrate processing apparatus may form a crack serving as a starting point for peeling the combined substrate  150  into the processing target substrate  100  and the support substrate  130 . In this case, the processing target substrate  100  and the combined substrate  150  may be bonded to each other with an adhesive or the like. 
     The processing target substrate  100  is not limited to the silicon wafer. The processing target substrate  100  may be, for example, a silicon carbide wafer, a gallium nitride wafer, a gallium oxide wafer, or the like. In addition, the processing target substrate  100  may be a glass substrate. It is the same for the support substrate  130 . 
     This application claims priority to Japanese Patent Application No. 2019-104802, field on Jun. 4, 2019, which application is hereby incorporated by reference in their entirety. 
     EXPLANATION OF CODES 
     
         
         
           
               51 : First transfer device 
               61 : Bevel removing apparatus (substrate processing apparatus) 
               63 : Second transfer device 
               100 : Processing target substrate (first substrate) 
               107 : Fragment (processing residue) 
               130 : Support substrate (second substrate) 
               150 : Combined substrate 
               160 : Blade (processing tool) 
               220 : Chuck 
               221 : Substrate holding surface 
               230 : Rotating mechanism 
               250 : First storage table 
               260 : Second storage table 
               270 : Internal transfer mechanism 
               280 : Lower cup 
               281 : Lower cylindrical member 
               282 : Groove 
               283 : Lower lid 
               284 : Discharge opening 
               290 : Discharge pipe 
               291 : Suction device 
               292 : Suction box 
               296 : Detector 
               300 : Upper coved 
               301 : Upper cylindrical member 
               302 : Groove 
               303 : Ceiling member 
               304 : First horizontal member 
               330 : Processing unit 
               331 : Blade mounting unit (processing tool mounting unit, measuring device mounting unit) 
               332 : Mounting surface 
               340 : Driving unit 
               351 : First slider 
               352 : Second slider 
               353 : Elastic body 
               360 : Rotation supporting mechanism 
               370 : Height adjusting mechanism 
               380 : Rotation restricting mechanism 
               390 : Parallelism adjusting mechanism 
               391 : Base plate 
               392 : Height adjuster 
               501 : Correction unit 
               502 : Determination unit 
               503 : Processing controller 
               504 : Instruction transmitting unit 
             Gd: Guide rail