Patent Publication Number: US-2019193237-A1

Title: Pad temperature adjustment apparatus for adjusting temperature of polishing pad, and polishing apparatus

Description:
TECHNICAL FIELD 
     The present invention relates to a pad temperature adjustment apparatus for adjusting the temperature of a polishing pad, and to a polishing apparatus. 
     BACKGROUND ART 
     In a polishing apparatus, especially a Chemical Mechanical Polishing (CMP) device, it is known that the level of uniformity of polishing may change depending on the temperature of the polishing surface. JP2011-136406A discloses a substrate polishing apparatus equipped with a pad temperature adjustment apparatus for adjusting the temperature of the polishing surface of a polishing pad. 
     The polishing pad of a polishing apparatus is a consumable article and must be exchanged periodically. Further, when it is not necessary to adjust the temperature of the polishing pad, it is preferable to enable the elimination of thermal contact between the polishing pad and the pad temperature adjustment apparatus. Thus, at least one object of the present invention is to provide a pad temperature adjustment apparatus which contributes to at least one of exchange of a polishing pad and elimination of thermal contact between a polishing pad and a pad temperature adjustment means. 
     SUMMARY OF INVENTION 
     The present application discloses, as one embodiment, a pad temperature adjustment apparatus for adjusting the temperature of a polishing pad, the pad temperature adjustment apparatus including: a heat conduction part for conducting heat to the polishing pad; an arm(s) that extends from the heat conduction part, wherein a distal end of the arm is formed in a tapered shape; an arm mount(s) for installing the arm and that includes an arm guide, the arm guide having a tapered groove shape corresponding to the shape of the arm; and, a falling prevention member for preventing the arm from falling out of the arm guide. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front surface view of a polishing apparatus. 
         FIG. 2  is a front surface cross-section view of a pad temperature adjustment apparatus. 
         FIG. 3  is a front surface cross-section view of the pad temperature adjustment apparatus provided with an electrical heating/cooling member. 
         FIG. 4A  is a top surface view of a pad temperature adjustment apparatus. 
         FIG. 4B  is a front surface cross-section view of the pad temperature adjustment apparatus. 
         FIG. 5  is a right side surface view of a vertical movement apparatus and an arm mount. 
         FIG. 6  is a front surface view of a heat conduction part and an arm. 
         FIG. 7  is a cross-section view of the arm mount at the position of the cross-section line indicated as A-A in  FIG. 5 . 
         FIG. 8A  is a top surface view of a pad temperature adjustment apparatus. 
         FIG. 8B  is a front surface partial cross-section view of the pad temperature adjustment apparatus. 
         FIG. 9  is a right side surface view of a vertical movement apparatus and an arm mount. 
         FIG. 10  is a left side surface view of a heat conduction part and an arm. 
         FIG. 11  is a front surface cross-section view of the arm mount and the vertical movement apparatus. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     First Embodiment 
     In a first embodiment, a configuration in which a pad temperature adjustment apparatus  140  is detachably attached by a fixing tool such as a bolt to a vertical movement apparatus  150  will be explained.  FIG. 1  is a front surface view illustrating a polishing apparatus  100  according to the present embodiment. Herein,  FIG. 1  and the other drawings are schematic views. The size, position, shape, etc. of the parts illustrated in the drawings may differ from the size, position, shape, etc. in the actual device. In the following, the left- right direction in  FIG. 1  will be referred to as the X-direction (with the right side of the paper surface of  FIG. 1  as the positive side), the direction perpendicular to the paper surface in  FIG. 1  will be referred to as the Y-direction (with the front side of the paper surface of  FIG. 1  as the positive side), and the up-down direction in  FIG. 1  will be referred to as the Z-direction (with top side of the paper surface of  FIG. 1  as the positive side). The polishing apparatus  100  in  FIG. 1  is a so-called “rotary-type” CMP device. However, as long as it is a device in which the temperature adjustment of the polishing pad is necessary, the polishing apparatus  100  may be a CMP device of a type other than the rotary type, and may be a polishing apparatus other than a CMP device. The polishing apparatus  100  in  FIG. 1  includes: a polishing table  110 ; a polishing head  120 ; a discharge mechanism  130 ; a pad temperature adjustment apparatus  140 ; and a vertical movement apparatus  150 . The polishing apparatus  100  further includes a control part  160  for controlling each element. 
     The polishing apparatus  100  includes the polishing table  110 . A polishing pad  111  is detachably attached to the top surface of the polishing table  110 . The polishing table  110  is rotatable in at least one direction by a motor or the like (not illustrated). The polishing table  110  in  FIG. 1  is rotatable in the counter clockwise direction when viewed from above. 
     The polishing apparatus  100  further includes the polishing head  120 . The polishing head  120  is provided above the polishing table  110  so as to oppose the polishing table  110 . A substrate  121  is detachably attached to the bottom surface of the polishing head  120 . The polishing head  120  is rotatable in at least one direction by a motor or the like (not illustrated). The polishing head  120  in  FIG. 1  is rotatable in the counter clockwise direction (in the same direction as the rotation direction of the polishing table  110 ) when viewed from above. Further, the polishing head  120  can be moved vertically by a head vertical movement apparatus (not illustrated). 
     The substrate  121  will be polished by pressing the substrate  121  against the polishing pad  111  on the polishing table  110  and rotating at least one, preferably both, of the polishing table  110  and the polishing head  120 . 
     The polishing apparatus  100  further includes the discharge mechanism  130  for discharging a liquid such as polishing liquid, a chemical liquid, and/or a washing water toward the polishing surface. The discharge mechanism  130  in  FIG. 1  includes a discharge pipe  132  that extends from a liquid supply source  131  provided near of the polishing table  110 . The liquid supply source  131  may be a part that constitutes a portion of the polishing apparatus  100 . Additionally or alternatively, a liquid supply source  131  that is separate and independent from the polishing apparatus  100  may be used. The discharge pipe  132  in  FIG. 1  passes over the polishing table  110  and extends up to approximately the center portion of the polishing table  110 . The polishing liquid is preferably discharged from the discharge pipe  132  during polishing of the substrate  121 . The washing water is preferably discharged from the discharge pipe  132  during washing of the polishing pad  111  and/or the substrate  121 . The number of the liquid supply source  131  and the discharge pipe  132  is not limited to one. 
     The polishing apparatus  100  further includes the pad temperature adjustment apparatus  140  for adjusting the temperature of the polishing pad  111 . The pad temperature adjustment apparatus  140  in  FIG. 1  includes: a heat conduction part  141 ; an arm  142 ; and a heating/cooling member  143 . The heat conduction part  141  is provided on or above the polishing table  110 , and is provided for conducting heat (for exchanging heat) between the heat conduction part  141  and the polishing pad  111  (for conducting heat to the polishing pad). The arm  142  extends from the heat conduction part  141  toward the vertical movement apparatus  150 . Further, the arm  142  is detachably fixed to the vertical movement apparatus  150 . The heating/cooling member  143  is a mechanism for heating and/or cooling the heat conduction part  141 . The heating/cooling member  143  in  FIG. 1  includes a heat medium flow passage  145  for a heat medium that is supplied from a heat medium source  144 . The heat medium source  144  may be a part that constitutes a portion of the polishing apparatus  100 . Additionally or alternatively, a heat medium source  144  that is separate and independent from the polishing apparatus  100  may be used. The heat medium that is supplied from the heat medium source  144  may be a heat medium for heating or a heat medium for cooling. As the heat medium, for example, water may be used. The heat medium source  144  may include a heater and/or a cooler (not illustrated) for heating and/or cooling the heat medium. Additionally or alternatively, the heat medium source  144  may be configured so as to retain a heat medium that has already been heated and/or cooled. The heat medium source  144  may include a pump (not illustrated) for flowing the heat medium toward the heat medium flow passage. 
     The heat medium flow passage  145  is provide to the inside of the heat conduction part  141 . Therefore, the heat conduction part  141  is heated and/or cooled by flowing the heat medium from the heat medium source  144  to the heat medium flow passage  145 . The number of the heat medium source  144  and the heat medium flow passage  145  is not limited to one. For example, as the heat medium source  144 , a first heat medium source  144  that supplies hot water and a second heat medium source  144  that supplies cold water may be provided. If a plurality of the heat medium sources  144  are provided, one heat medium flow passage  145  may be connected to each heat medium source  144 . The plurality of heat medium sources  144  may also share a single heat medium flow passage  145 . Further, a plurality of heat medium flow passages  145  may be connected to one heat medium source  144 . 
     In the case that a “raising mechanism (refer to PTL1)” for retracting the pad temperature adjustment apparatus  140  is added to the configuration of  FIG. 1 , the pad temperature adjustment apparatus  140  and the discharge mechanism  130  may collide during retraction of the pad temperature adjustment apparatus  140 . Therefore, in the configuration of  FIG. 1 , it is difficult to exchange the polishing pad  111  and/or to eliminate thermal contact between the polishing pad  111  and the pad temperature adjustment apparatus  140  by using a “raising mechanism”. Note that, depending on the configuration of the polishing apparatus  100 , a part other than the discharge mechanism  130  may collide with or interfere with the pad temperature adjustment apparatus  140 . 
     Thus, the polishing apparatus  100  in  FIG. 1  includes the vertical movement apparatus  150  for vertically moving at least a portion of the pad temperature adjustment apparatus  140 . More specifically, the vertical movement apparatus  150  is configured so as to vertically move at least the arm  142  and the heat conduction part  141 . The vertical movement apparatus  150  is detachably fixed to the arm  142 . In the example of  FIG. 1 , the arm  142  is fixed to the vertical movement apparatus  150  by a fixing tool  151 . For the convenience of illustration,  FIG. 1  illustrates the fixing tool  151  in a removed state. As an example of the fixing tool  151 , mention may be made of a bolt. The vertical movement apparatus  150  may be configured to vertically move the heat medium source  144 . Additionally or alternatively, the heat medium flow passage  145  may be formed from a flexible member (for example, bellows, or a tube that is at least partially made of an elastic body or flexible member (a tube made of rubber or resin, etc.)), and the vertical movement apparatus  150  may be configured so as not to vertically move the heat medium source  144 . 
     When it is necessary to adjust the temperature of the polishing pad  111 , the control part  160  controls the vertical movement apparatus  150  such that the heat conduction part  141  and the polishing pad  111  thermally contact each other. In other words, the vertical movement apparatus  150  lowers the heat conduction part  141  until the heat conduction part  141  contacts the polishing pad  111 . In the state in which the heat conduction part  141  and the polishing pad  111  are in contact, the control part  160  controls the flow rate and/or temperature of the heat medium, and thereby the temperature of the polishing pad  111  is adjusted. 
     When it is not necessary to adjust the temperature of the polishing pad  111 , the control part  160  controls the vertical movement apparatus  150  so that the heat conduction part  141  and the polishing pad  111  no longer thermally contact each other. In other words, the vertical movement apparatus  150  raises the heat conduction part  141  until the heat conduction part  141  no longer contacts the polishing pad  111 . Additionally or alternatively, when it is not necessary to adjust the temperature of the polishing pad  111 , control of the heat medium by the control part  160  may be stopped. 
     When it is necessary to exchange the polishing pad  111 , the control part  160  controls the vertical movement apparatus  150  so that a sufficient gap is formed between the heat conduction part  141  and the polishing pad  111 . In other words, the vertical movement apparatus  150  raises the heat conduction part  141  until a sufficient gap is formed between the heat conduction part  141  and the polishing pad  111 . When it is necessary to exchange the polishing pad  111 , a user may release the fixation by the fixing tool  151  and remove the pad temperature adjustment apparatus  140 . The pad temperature adjustment apparatus  140  which has been removed may be stored outside of the polishing apparatus  100 . Within the polishing apparatus  100 , a mechanism for storing the pad temperature adjustment apparatus  140  which has been removed may be provided. By raising the heat conduction part  141  or removing the heat conduction part  141 , the space necessary for exchanging the polishing pad  111  can be secured. In order to facilitate the peeling of the polishing pad  111  from the polishing table  110 , the top surface of the polishing table  110  is preferably coated with a material having a low coefficient of friction (for example, Teflon). 
     Configuring the pad temperature adjustment apparatus  140  to be detachable is advantageous in that it becomes easy to clean the pad temperature adjustment apparatus  140 , especially the heat conduction part  141 . The polishing liquid may adhere or become fixed to the pad temperature adjustment apparatus  140 , especially to the heat conduction part  141 , and thus the ease of cleaning is important. 
     The pad temperature adjustment apparatus  140  will now be explained in detail using  FIG. 2 .  FIG. 2  is a front surface cross-section view of the pad temperature adjustment apparatus  140 .  FIG. 2  also illustrates the vertical movement apparatus  150  that is connected to the pad temperature adjustment apparatus  140 . 
     The heat medium flow passage  145  in  FIG. 2  is configured to supply the heat medium from the heat medium source  144 , and to collect the heat medium that was supplied. By configuring the heat medium flow passage  145  as shown in  FIG. 2  so as to circulate the heat medium within the heat conduction part  141 , the heat conduction part  141  can be stably heated and/or cooled. The heat medium collected by the heat medium flow passage  145  may heated and/or cooled for reuse, or may be discarded. The heat medium flow passage  145  preferably occupies at least 30% of the volume of the heat conduction part  141 , more preferably at least 40% of the volume, and most preferably at least 50% of the volume. 
     An uneven structure  200  is preferably formed on the bottom surface of the heat conduction part  141 , i.e. on the portion of the heat conduction part  141  that contacts the polishing pad  111 . If the bottom surface of the heat conduction part  141  is completely flat, the heat conduction part  141  may become adhered to the polishing pad  111  due to the surface tension of the liquid (the polishing liquid or the washing water, etc.) between the heat conduction part  141  and the polishing pad  111 . On the other hand, if the bottom surface of the heat conduction part  141  is completely flat, the heat can be efficiently conducted. Further, if the bottom surface of the heat conduction part  141  is completely flat, there are no recesses, and thus byproducts generated by the polishing do not accumulate in such recesses. In addition, if a heat conduction part  141  having no recesses is used, the flow of the polishing liquid does not become disturbed due to the polishing liquid passing through the recesses. 
     Instead of configuring the bottom surface of the heat conduction part  141  to be flat, providing the uneven structure  200  to the bottom surface of the heat conduction part  141  can prevent adhesion of the heat conduction part  141  to the polishing pad  111 . Further, by providing the uneven structure  200 , chattering between the heat conduction part  141  and the polishing pad  111  can be prevented. It is preferable to determine whether to configure the bottom surface of the heat conduction part  141  to be flat or to provide the uneven structure  200  to the bottom surface of the heat conduction part  141  upon taking into account the degree of adhesion of the heat conduction part  141 , the heat conduction efficiency from the heat conduction part  141 , and the like. In the case that the uneven structure  200  is provided, the region to which the uneven structure  200  is provided and the specific structure of the uneven structure  200  are appropriately determined based on the necessary heat conduction efficiency and the like. 
     The polishing apparatus  100  preferably includes a sensor  210  for detecting that the arm  142  and the vertical movement apparatus  150  are correctly fixed to each other. The sensor  210  may be controlled by the control part  160  (not illustrated in  FIG. 2 ). In  FIG. 2 , as the sensor  210 , a proximity sensor is provided between the arm  142  and the vertical movement apparatus  150 . As another example, a microswitch, an optical sensor, and a camera, etc. can be used. Due to the sensor  210 , the substrate  121  can be prevented from being polished in a state in which the pad temperature adjustment apparatus  140  has been removed or a state in which the pad temperature adjustment apparatus  140  is not correctly attached. 
     A heating/cooling member  143  of another configuration may also be used.  FIG. 3  is a front surface cross-section view of the pad temperature adjustment apparatus  140  provided with an electrical heating/cooling member  143 . The heating/cooling member  143  in  FIG. 3  includes a heater  300  and a cooler  310 . The heater  300  and the cooler  310  are provided to the inside of the heat conduction part  141 . Further, the heater  300  and the cooler  310  are connected to a power source  320 . The power source  320  may be a part that constitutes a portion of the polishing apparatus  100 . Additionally or alternatively, a power source  320  that is separate and independent from the polishing apparatus  100  may be used. The heating/cooling member  143  may include only the heater  300  or only the cooler  310 . 
     A heating/cooling member  143  in which the configuration of  FIG. 2  and the configuration of  FIG. 3  are combined may also be used. For example, a heating/cooling member  143  including the heat medium flow passage  145 , which is connected to the heat medium source  144  that supplies cold water, and the heater  300  can be used. 
     Second Embodiment 
     In a second embodiment, a configuration in which the heat conduction part  141  can be easily attached/detached will be explained. This embodiment will be explained referring to  FIGS. 4, 5, and 6 .  FIG. 4  illustrates a pad temperature adjustment apparatus  140  according to the present embodiment.  FIG. 4A  is a top surface view of the pad temperature adjustment apparatus  140 .  FIG. 4B  is a front surface cross-section view of the pad temperature adjustment apparatus  140 .  FIG. 4B  also illustrates a vertical movement apparatus  150 .  FIG. 5  is a right side surface view of the vertical movement apparatus  150  and an arm mount  400  according to the present embodiment.  FIG. 6  is a front surface view of a heat conduction part  141  and an arm  142  according to the present embodiment. The arrangement pattern of the heating/cooling member  143  on the inside of the heat conduction part  141  shown in  FIG. 4  is one example, and any other arrangement pattern may be used. 
     The pad temperature adjustment apparatus  140  according to the present embodiment includes the heat conduction part  141  and two arms  142 , as well as the arm mount  400 . The arm mount  400  is fixed to the vertical movement apparatus  150 . The arm mount  400  is provided for installing (mounting) the arms  142 . The arm mount  400  is provided with arm guides  410  in a number (two in this embodiment) corresponding to the number of arms  142 . The user can insert the arms  142  into the arm mount  400  along the arm guides  410 , and can pull out the arms  142  from the arm mount  400 . The arm guides  410  according to the present embodiment have a groove-shaped structure. The number of arms  142  is not limited to two, and one arm or three or more arms may be used. The number of arm guides  410  is preferably the same as the number of arms  142 . However, the number of arm guides  410  may be different than the number of arms  142 . 
     Each arm  142  is installed in the arm mount  400  by a plunger  420 . When the arm  142  has been inserted into the arm mount  400 , a pin of the plunger  420  is engaged with a plunger hole  430  provided to the arm  142 . The number, size, position, etc. of the plunger  420  and the plunger hole  430  may be designed as appropriate. Each arm  142  is preferably provided with a plunger guide  440  for guiding the pin of the plunger  420  to the plunger hole  430 . The plunger guide  440  in the present embodiment is a groove that becomes shallower approaching the plunger hole  430 . 
     The user inserts the arms  142  along the arm guides  410  until the pins of the plungers  420  engage with the plunger holes  430 , and thereby the heat conduction part  141  is attached to the vertical movement apparatus  150 . The arms  142  may be inserted automatically by some kind of conveyance mechanism. In the present embodiment, the heat conduction part  141  can be easily attached to the vertical movement apparatus  150  without requiring the labor of screwing or the like. 
     The plungers  420  may be configured such that the engagement between the pin of the plunger  420  and the plunger hole  430  can be released by, for example, pulling the head part of the plunger  420 . The heat conduction part  141  is removed from the vertical movement apparatus  150  by pulling out the arms  142  from the arm mount  400  in a state in which the engagement between the pins of the plungers  420  and the plunger holes  430  has been released. In order to maintain the state in which the engagement between the pins of the plungers  420  and the plunger holes  430  has been released, the plungers  420  preferably include a lock mechanism. In the present embodiment, the heat conduction part  141  can be easily removed from the vertical movement apparatus  150  without requiring the labor of unscrewing or the like. 
     Each arm  142  is preferably provided with a handle  450  for facilitating the insertion and pulling out of the arm  142 . The handle  450  may be provided to the heat conduction part  141  as long as it does not obstruct the polishing of the substrate  121  and the temperature adjustment of the polishing pad  111 . The arm mount  400  is preferably provided with a spring  460  for assisting in the pulling out of the arms  142 . The spring  460  may be provided to each arm  142 . The spring  460  is provided so as to push the arms  142  in the direction in which the arms  142  are pulled out (toward the positive side in the X-direction in  FIG. 4 ). The user can easily pull out the arms  142  due to the pushing force generated by the spring  460 . For the convenience of illustration, the spring  460  is illustrated in a contracted state. 
     A coupling element (in this case two coupling elements)  470  is provided to the arm mount  400 . In the illustrated example, the heat medium source  144  and the heat medium flow passage  145  are detachably connected by the coupling elements  470  for fluid. When attaching the heat conduction part  141 , the distal ends of the heat medium flow passage  145  are inserted into the coupling elements  470 . In the case that the heat medium is a fluid, the heat medium flow passage  145  and the coupling elements  470  are preferably sealed by a one- touch joint, an O-ring, a metal seal, etc. In the case that the heat medium is a fluid, a check valve (not illustrated) may be provided to each coupling element  470 . Additionally or alternatively, the check valve may be provided to a part other than the coupling elements  470 , such as the distal ends of the heat medium flow passage  145 . By providing a check valve, fluid remaining within the parts can be prevented from flowing to the outside when the heat medium source  144  and the heat medium flow passage  145  have been disconnected. When an electrical part(s) is used as the heating/cooling member  143 , i.e. when the heating/cooling member  143  includes the heater  300  and/or the cooler  310 , coupling element(s)  470  for electric wiring may be used. The coupling element(s)  470  facilitate the separation of the heat medium source  144  and the heat medium flow passage  145 , and thus the heat conduction part  141  can be easily removed. Additionally or alternatively, the heat medium source  144  and the heat medium flow passage  145  can be connected by a piping or wiring that is expandable and/or flexible. 
     Depending on the shape of the arm guides  410 , the arms  142  may be inserted into the arm guides  410  in a tilted state and/or a state in which the arms  142  are shifted in the up- down/left-right direction in  FIG. 5  (Y-direction and/or Z-direction). Therefore, the heat medium flow passage  145  may be inserted into the coupling elements  470  in a tilted state and/or a state in which the heat medium flow passage  145  is shifted in the up-down/left-right direction. If the amount of tilting and/or the amount of shifting is large, the heat medium source  144  and the heat medium flow passage  145  may not be able to be appropriately connected. 
     Thus, in the present embodiment, a gap is provided between each coupling element  470  and the arm mount  400 .  FIG. 7  is a cross-section view of the arm mount  400  at the position of the cross-section line indicated as A-A in  FIG. 5 . The coupling element  470  shown in  FIG. 7  shall be explained as a fluid coupling element. The coupling element  470  has a T-shaped cross-section shape, and a first through hole  700  for passing a fluid is provided to the center of the coupling element  470 . The arm mount  400  is provided with a second through hole  710  for inserting the small-diameter part (the portion corresponding to the vertical bar of the T) of the coupling element  470 . Once the small-diameter part of the coupling element  470  has been inserted into the second through hole  710 , a stopper  720  (a retaining ring or a clamp, etc.) is attached to the small-diameter part of the coupling element  470 . The diameter of the second through hole  710  is determined such that a gap exists between the second through hole  710  and the small-diameter part of the coupling element  470 . Specifically, the diameter of the second through hole  710  (indicated as “D hole ” in  FIG. 7 ) can be set to be greater by at least 0.1 mm, at least 1 mm, at least 5 mm, at least 10 mm, or at least 20 mm than the diameter of the small-diameter part of the coupling element  470  (indicated as “D cpl ” in  FIG. 7 ). The diameter of the second through hole  710  is preferably set to be smaller than the diameter of the large-diameter part of the coupling element  470  so that the coupling element  470  does not fall out from the second through hole  710 . 
     Further, the distance between the portion of the large-diameter part of the coupling element  470  that can contact the arm guide  410  and the stopper  720  (indicated as “1” in  FIG. 7 ) is determined so as to be greater than the thickness of the portion of the arm guide  410  in which the second through hole  710  is provided (indicated as “t” in  FIG. 7 ). Specifically, the distance between the portion of the large-diameter part of the coupling element  470  that can contact the arm guide  410  and the stopper  720  can be set to be longer by at least 0.1 mm, at least 1 mm, at least 5 mm, at least 10 mm, or at least 20 mm than the thickness of the portion of the arm guide  410  in which the second through hole  710  is provided. 
     According to the configuration shown in  FIG. 7 , the gap provided between the coupling elements  470  and the arm mount  400  absorbs tilting and/or up-down/left-right shifting of the heat medium flow passage  145 . Therefore, even if the heat medium flow passage  145  is inserted into the coupling elements  470  in a tilted state and/or a state in which the heat medium flow passage  145  is shifted in the up-down/left-right direction, the heat medium source  144  and the heat medium flow passage  145  can be appropriately connected. Further, the gap provided between the coupling elements  470  and the arm mount  400  also serves as a clearance (a play) for thermal expansion of the coupling elements  470  and/or the arm mount  400 . 
     In particular, in the case that the heat medium is a fluid and the connection between the coupling elements  470  and the heat medium flow passage  145  is inappropriate, leakage of the fluid may occur. Further, in the case that each coupling element  470  is provided with a check valve and the connection between the coupling elements  470  and the heat medium flow passage  145  is inappropriate, the check valve may inhibit the flow of the heat medium. A sensor (not illustrated) may be provided near the coupling elements  470  in order to confirm that the coupling elements  470  and the heat medium flow passage  145  are appropriately connected. 
     In the configuration of the second embodiment, the vertical movement apparatus  150  does not necessarily have to be provided. However, the vertical movement apparatus  150  is preferably provided in order to facilitate the removal of the heat conduction part  141 , to facilitate the exchange of the polishing pad  111 , and to separate the heat conduction part  141  from the polishing pad  111  when temperature adjustment is unnecessary. 
     In the configuration of the second embodiment as well, the polishing pad  111  can be exchanged and/or thermal contact between the heat conduction part  141  and the polishing pad  111  can be eliminated without using a “raising mechanism (refer to PTL1)”. 
     Third Embodiment 
     In the configuration explained in the second embodiment, it is necessary to provide a clearance between the arms  142  and the arm guides  410  in order to insert the arms  142  into the arm guides  410 . Further, it is also necessary to provide a clearance between the pins of the plungers  420  and the plunger holes  430 . The clearances between these parts causes rattling of the arms  142 . Rattling of the arms  142  may lead to a shift in the position at which the heat conduction part  141  contacts the polishing pad  111 , and may make it difficult to accurately adjust the temperature of the polishing pad  111 . In particular, if the heat conduction part  141  shifts in the radial direction (X-direction) of the polishing table  110 , the area of the polishing pad  111  which is intended to contact the heat conduction part  141  may no longer contact the heat conduction part  141 . 
     In addition, abrasion powder may be produced if the arms  142  and the arm guides  410  rub against each other during the insertion and pulling out of the arms  142 . Such abrasion powder can ride the flow of a gas and/or liquid in the polishing apparatus  100 , eventually reaching the polishing pad  111 . Abrasion powder on the polishing pad  111  may cause abnormal polishing of the substrate  121 . Further, abrasion powder which has adhered to the substrate  121  may cause abnormalities in the process(es) after the substrate polishing. Moreover, abrasion of the arms  142  and/or the arm guides  410  may cause a deterioration in the slidability between the arms  142  and the arm guides  410 , and this can lead to difficulties in the insertion and pulling out of the arms  142 . 
     If the clearance between the parts is decreased in order to reduce rattling of the arms  142 , it is conceivable that arms  142  and the arm guides  410  will strongly rub against each other. Conversely, if the clearance between the parts is increased in order to reduce the abrasion between the arms  142  and the arm guides  410 , it is believed that rattling of the arms  142  will increase. 
     Thus, in the third embodiment, a configuration for reducing the rattling of the arms  142  and/or the abrasion between the arms  142  and the arm guides  410  will be explained referring to  FIGS. 8, 9, and 10 .  FIG. 8  illustrates a pad temperature adjustment apparatus  140  according to the present embodiment.  FIG. 8A  is a top surface view of the pad temperature adjustment apparatus  140 .  FIG. 8B  is a front surface partial cross-section view of the pad temperature adjustment apparatus  140  (the heat medium source  144 , the vertical movement apparatus  150 , and the arm mount  400  are illustrated in cross-section, and the heat conduction part  141  and the arms  142  are illustrated in non-cross-section).  FIG. 8B  also illustrates the vertical movement apparatus  150 .  FIG. 9  is a right side surface view of the vertical movement apparatus  150  and the arm mount  400  according to the present embodiment.  FIG. 10  is a left side surface view of the heat conduction part  141  and arms  142  according to the present embodiment. 
     The third embodiment shares common features with the second embodiment in that the arms  142  are configured such that they can be inserted into the arm guides  410 . Meanwhile, the shapes of the arms  142  and the arm guides  410  in the third embodiment differs from the shapes thereof in the second embodiment. 
     As is best illustrated in  FIG. 8B , the distal end of at least one of the arms  142  (in this illustrated example, both of the two arms) according to the present embodiment is formed in a tapered shape. More specifically, the top part of the distal end, which is the end that is spaced apart from the heat conduction part  141 , of each arm  142  is formed in a tapered shape. Herein, “the distal end of the arm  142 ” can be rephrased as “the portion of the arm  142  that is inserted into the arm guide  410 ”. Additionally or alternatively, the bottom part of the arm  142  may be formed in a tapered shape. However, the bottom part of the arm  142  preferably has a non-tapered shape in order to prevent the arm  142  from accidentally falling out. The shape of the arm guide  410  corresponds to the shape of the arm  142 . In other words, the arm guide  410  is formed in a tapered groove shape. The taper angle of the arm  142  and the arm guide  410  may be any angle, and can be set to, for example, an angle from 10 degrees to 45 degrees. The taper angle may be an angle less than 10 degrees, and may be an angle greater than 45 degrees. The taper angle is preferably determined such that length of the tapered portion of the arm  142  is longer than the length of the portion of the arm  142  that is inserted into the arm guide  410 . 
     In the present embodiment, a falling prevention member  810  is provided in order to install the arms  142  in the arm guides  410  of the arm mount  400 , i.e. in order to prevent the arms  142  from falling out from the arm guides  410 . Specifically, as the falling prevention member  810 , a hook  811  is provided to the arm  142 , and a fastener  812  is provided to the arm mount  400 . In the illustrated example, one set of the hook  811  and the fastener  812  is provided, but two or more sets of the hook  811  and the fastener  812  can be used. When the hook  811  and the fastener  812  are engaged with each other, the arms  142  are pressed to the arm mount  400 , and thus the arms  142  are prevented from falling out. Additionally or alternatively, the fastener  812  may be provided to the arm  142  and the hook  811  may be provided to the arm mount  400 . As a further additional or alternative example, instead of the hook  811  and the fastener  812 , other elements such as a spring, a plunger, a pin, a bolt, a nut, a wire, and/or a string, etc. can be used. The falling prevention member  810  may be a member that prevents the arms  142  from falling out using an electromagnetic force generated by a permanent magnet or an electromagnet, etc. Further, the falling prevention member  810  may be provided at an arbitrary location, for example, the fastener  812  may be provided to the vertical movement apparatus  150 . 
     According to the configuration of the third embodiment, if the arms  142  are not completely inserted into the arm guides  410 , the arms  142  and the arm guides  410  will not rub against each other much. Therefore, according to the configuration of the third embodiment, the generation of abrasion powder can be reduced. Further, a deterioration in the slidability can be prevented by reducing the abrasion. In addition, since the arms  142  and the arm guides  410  are configured in a tapered shape, the arms  142  can be easily inserted and pulled out. 
     When the arms  142  are completely inserted into the arm guides  410 , the tapered surface of the arms  142  and the tapered surface of the arm guides  410  contact each other. In other words, when the arms  142  are completely inserted into the arm guides  410 , the clearance in the X-direction between the arms  142  and the arm guides  410  is substantially zero (excluding clearance that is generated by the effects of manufacturing errors, assembly errors, warping of the parts, deterioration over time, and differences in the coefficient of thermal expansion, etc.). Thus, rattling in the X-direction of the arms  142  is reduced. Therefore, according to the configuration of the third embodiment, the heat conduction part  141  can be positioned with high accuracy. 
     More preferably, at least one of the arms  142  is formed in a dovetail tenon shape as is best illustrated in  FIG. 10 . The term “dovetail tenon shape” as used herein includes a “half-dovetail tenon shape”. Further, as is best illustrated in  FIG. 9 , the arm guide  410  for the dovetail tenon-shaped arm is preferably formed in a dovetail groove shape. The term “dovetail groove shape” as used herein includes a “half-dovetail groove shape”. Rattling in the Y-direction of the arms  142  is reduced by the dovetail tenon structure and the dovetail groove structure. Unlike the illustrated example, a plurality of the arms  142  and the arm guides  410  may be configured in a dovetail tenon shape or a dovetail groove shape. The angle of the dovetail tenon and the dovetail groove may be any angle, and can be set to, for example, 45 degrees or 60 degrees. 
     An alternative example of the present embodiment is shown in  FIG. 11 .  FIG. 11  is a front surface cross-section view of the arm mount  400  and the vertical movement apparatus  150 . However, for the convenience of illustration, the coupling elements  470  are not illustrated. In the example of  FIG. 11 , the arm guide  410  is configured in an overall tapered groove shape by a groove  1100 , which is rectangular when viewed from the front surface, and a block  1110 , which has a trapezoidal shape when viewed from the front surface. The block  1110  is at least partially positioned on the inside of the rectangular groove  1100 . In the example of  FIG. 11 , the block  1110  is entirely positioned on the inside of the rectangular groove  1100 . The block  1110  is fixed by a fixing tool  1120  such as a bolt. Further, at least one of the fixation position and the fixation angle of the block  1110  is adjustable. By moving the fixation position of the block  1110  in the X-direction, the insertion length of the arm  142  can be adjusted, and thus the position of the heat conduction part  141  can be adjusted. By changing the fixation angle of the block  1110 , the taper angle of the arm guide  410  can be adjusted according to the angle of the tapered portion of the heat conduction part  141 . An arm guide  410  that has a tapered groove shape and a dovetail groove shape can be configured by the rectangular groove  1100  and the block  1110 . 
     Several embodiments of the present invention have been explained above, but these embodiments of the invention are for the purpose of facilitating the understanding of the present invention, and are not intended to limit the present invention. Further, the matters explained in a certain embodiment can be applied to another embodiment as long as they do not contradict each other. For example, the uneven structure  200  and/or the sensor  210 , etc. explained in the first embodiment can be applied to the second embodiment or the third embodiment. Similarly, the plunger  420  and/or the spring  460 , etc. explained in the second embodiment can be applied to the third embodiment. 
     The present invention may be modified or improved without departing from the gist of the invention, and the present invention obviously includes equivalents thereof. Further, the constituent elements described in the scope of the claims and the specification may be arbitrarily combined or eliminated within a scope in which the above-described problems can be at least partially solved or a scope in which the effects can be at least partially achieved. 
     The present application discloses, as one embodiment, a pad temperature adjustment apparatus for adjusting the temperature of a polishing pad, the pad temperature adjustment apparatus including: a heat conduction part for conducting heat to the polishing pad; an arm(s) that extends from the heat conduction part, wherein a distal end of the arm is formed in a tapered shape; an arm mount(s) for installing the arm and that includes an arm guide, the arm guide having a tapered groove shape corresponding to the shape of the arm; and a falling prevention member for preventing the arm from falling out of the arm guide. 
     This pad temperature adjustment apparatus may achieve, as one example, an effect in which rattling of the arm and/or abrasion between the arm and the arm guide can be reduced. Further, this pad temperature adjustment apparatus may achieve, as one example, an effect in which rattling of the arm in the X-direction can be reduced. 
     The present application further discloses, as one embodiment, a pad temperature adjustment apparatus, wherein the arm includes a plurality of arms, wherein at least one of the plurality of arms is formed in a dovetail tenon shape, and the arm guide for the dovetail tenon-shaped arm is formed in a dovetail groove shape. 
     This pad temperature adjustment apparatus may achieve, as one example, an effect in which rattling of the arm in the Y-direction can be reduced. 
     The present application further discloses, as one embodiment, a pad temperature adjustment apparatus further including a heating/cooling member being provided to the inside of the heat conduction part. The present application further discloses, as one embodiment, a pad temperature adjustment apparatus wherein the heating/cooling member includes a heat medium flow passage for flowing a heat medium, and the arm mount is provided with a coupling element that is connected to the heat medium flow passage when the arm is installed in the arm mount. 
     The pad temperature adjustment apparatus and the heating/cooling member are explained in detail in the content disclosed above. 
     The present application further discloses, as one embodiment, a pad temperature adjustment apparatus wherein the coupling element is provided so that a gap is formed between the coupling element and the arm mount. 
     This pad temperature adjustment apparatus may achieve, as one example, an effect in which it becomes easier to appropriately connect the heat medium source and the heat medium flow passage. 
     The present application further discloses, as one embodiment, a pad temperature adjustment apparatus wherein the heating/cooling member includes a heater and/or a cooler. 
     Another example of the heating/cooling member is explained in the content disclosed above. 
     The present application further discloses, as one embodiment, a pad temperature adjustment apparatus wherein the arm guide having a tapered groove shape is formed by a rectangular groove and a block that is at least partially positioned on the inside of the rectangular groove, wherein a fixation position and/or a fixation angle of the block is adjustable. 
     This pad temperature adjustment apparatus may achieve, as one example, an effect in which the insertion length of the arm and/or the taper angle of the arm guide can be adjusted. 
     The present application further discloses, as one embodiment, a polishing apparatus including: a polishing table for holding a polishing pad; a polishing head that is provided above the polishing table so as to oppose the polishing table; and the pad temperature adjustment apparatus disclosed in the present specification. The present application further discloses, as one embodiment, a polishing apparatus that further includes a vertical movement apparatus for vertically moving the pad temperature adjustment apparatus. 
     A polishing apparatus including the pad temperature adjustment apparatus disclosed in the present specification is explained in detail in the content disclosed above. 
     The present application further discloses, as one embodiment, a polishing apparatus wherein a surface of the polishing table to which the polishing pad is attached is coated with a material having a low coefficient of friction. 
     This polishing apparatus may achieve, as one example, an effect in which it becomes easier to peel the polishing pad away from the polishing table.