Patent Publication Number: US-2004053559-A1

Title: Polishing apparatus and method of bonding and removing expendable replacement components thereof

Description:
BACKGROUND OF THE INVENTION  
       [0001] The present invention relates to a polishing apparatus having a top ring for holding a substrate and a polishing table having a polishing surface, wherein the substrate held by the top ring is brought into contact with the polishing surface, and in this state, the polishing table and the substrate are moved relative to each other to thereby polish the substrate. The present invention also relates to a method of bonding and removing expendable replacement components of the polishing apparatus.  
       [0002] Conventionally, a polishing apparatus for polishing substrates, e.g. semiconductor substrates, has a turntable with a polishing cloth bonded to the top surface thereof. A substrate held by a top ring or the like is brought into contact with the upper surface of the polishing cloth on the turntable. In this state, the turntable is rotated, and the top ring is also rotated, thereby polishing a surface to be polished of the substrate by a relative motion between the polishing cloth and the substrate.  
       [0003] To bond the polishing cloth to the top surface of the turntable in the polishing apparatus arranged as stated above, as shown in FIG. 1, an adhesive  12  is applied to either or both of the back of the polishing cloth  11  and the top surface of the turntable  10  (in the illustrated example, the adhesive  12  is applied to the back of the polishing cloth  11 ). As the adhesive  12 , an adhesive exhibiting high peel strength has heretofore been used to prevent the polishing cloth  11  from undesirably separating from the turntable  10  during the substrate polishing process.  
       [0004] For this reason, much human power and a special jig are required to remove the polishing cloth  11  from the turntable  10  at the time of replacement of the polishing cloth  11 . Further, because much human power is needed to remove it, the polishing cloth  11  is damaged to a considerable extent when removed from the turntable  10 . Therefore, if the polishing cloth  11  is removed before the time for replacement, it cannot be reused.  
       [0005] Although an adhesive that is unlikely to remain on the top surface of the turntable  10  after the polishing cloth  11  has been removed therefrom is used as the adhesive  12 , a certain amount of adhesive is unavoidably left on the top surface of the turntable  10 . Therefore, it has been invariably necessary to remove the remaining adhesive by wiping the top surface of the turntable  10  with alcohol every time the polishing cloth  11  is removed. The above-described operation of removing the polishing cloth  11  and the operation of wiping the top surface of the turntable  10  with alcohol to remove the remaining adhesive are time-consuming and difficult.  
       [0006] Similar problems are also experienced with the bonding and removal of a backing film, which is bonded to the substrate holding surface of the top ring of the polishing apparatus, and a pressure ring bonded to the top ring and positioned at the outer peripheral portion of the substrate as held by the top ring.  
       SUMMARY OF THE INVENTION  
       [0007] The present invention was made in view of the above-described circumstances.  
       [0008] Accordingly, an object of the present invention is to provide a polishing apparatus wherein expendable replacement components such as a polishing cloth, a backing film and a pressure ring can be readily bonded to and removed from the polishing table and the top ring, and particularly, the expendable replacement components bonded to the polishing table and the top ring can be removed easily with minimal removal force, and also provide a method of bonding and removing such expendable replacement components of the polishing apparatus.  
       [0009] According to a first aspect thereof, the present invention provides a polishing apparatus having a top ring for holding a substrate and a polishing table having a polishing surface, wherein the substrate held by the top ring is brought into contact with the polishing surface, and in this state, the polishing table and the substrate are moved relative to each other to thereby polish the substrate. In the polishing apparatus, expendable replacement components to be bonded to the top ring and the polishing table are bonded to the top ring and the polishing table in such a manner that pieces of heat-sensitive adhesive (agent) or adhesive tape are interposed between the expendable replacement components on the one hand and the top ring and the polishing table on the other. The heat-sensitive adhesive tape is switchable between a non-adhesive state and a adhesive state according to whether the temperature thereof is higher or lower than a predetermined set temperature.  
       [0010] As stated above, pieces of heat-sensitive adhesive tape are interposed between the expendable replacement components on the one hand and the top ring and the polishing table on the other to bond the expendable replacement components to the top ring and the polishing table. Because the heat-sensitive adhesive tape has the nature of switching between a non-adhesive (non-tacky) state and a adhesive state according to whether the temperature thereof is higher or lower than a predetermined set temperature, the expendable replacement components can be bonded and removed easily by heating or cooling the heat-sensitive adhesive tape above or below the set temperature. Particularly, when the heat-sensitive adhesive tape is made non-adhesive by heating or cooling, the expendable replacement components can be removed easily with minimal removal force. Further, because the removal force is minimized, the expendable replacement components can be removed without being damaged.  
       [0011] According to a second aspect of the present invention, the expendable replacement components of the above-described polishing apparatus are at least one selected from the group consisting of a polishing cloth bonded to the top surface of the polishing table, a backing film bonded to the substrate holding surface of the top ring, and a pressure ring bonded to the top ring and positioned at the outer peripheral portion of the substrate as held by the top ring.  
       [0012] According to a third aspect thereof, the present invention provides an expendable replacement component bonding and removing method for use in a polishing apparatus. The polishing apparatus has a top ring for holding a substrate and a polishing table having a polishing surface. The substrate held by the top ring is brought into contact with the polishing surface, and in this state, the polishing table and the substrate are moved relative to each other to thereby polish the substrate. According to the method of the present invention, expendable replacement components to be bonded to the top ring and the polishing table are placed over the top ring and the polishing table in such a manner that pieces of heat-sensitive adhesive tape are interposed between the expendable replacement components on the one hand and the top ring and the polishing table on the other. The heat-sensitive adhesive tape is switchable between a non-adhesive state and a adhesive state according to whether the temperature thereof is higher or lower than a predetermined set temperature. Then, the heat-sensitive adhesive tape is heated above or cooled below the set temperature, thereby bonding the expendable replacement components to the top ring and the polishing table or removing the expendable replacement components bonded to the top ring and the polishing table.  
       [0013] As stated above, pieces of heat-sensitive adhesive tape are interposed between the expendable replacement components on the one hand and the top ring and/or the polishing table on the other, and the heat-sensitive adhesive tape is switched between a non-adhesive state and a adhesive state by heating or cooling it above or below the set temperature. Therefore, it is easy to bond and remove the expendable replacement components. Particularly, when the heat-sensitive adhesive tape is made non-adhesive, the expendable replacement components can be removed easily with minimal removal force.  
       [0014] According to a fourth aspect of the present invention, the expendable replacement components in the method according to the third aspect of the present invention are bonded to the top ring and the polishing table or removed therefrom by using a jig for heating or cooling the pieces of heat-sensitive adhesive tape interposed between the expendable replacement components on the one hand and the top ring and/or the polishing table on the other.  
       [0015] The heat-sensitive adhesive tape can be readily made non-adhesive by using the jig for heating or cooling the heat-sensitive adhesive tape as stated above.  
       [0016] According to a fifth aspect of the present invention, the expendable replacement components in the method according to the third or fourth aspect of the present invention are at least one selected from the group consisting of a polishing cloth bonded to the top surface of the polishing table, a backing film bonded to the substrate holding surface of the top ring, and a pressure ring bonded to the top ring and positioned at the outer peripheral portion of the substrate as held by the top ring.  
       [0017] According to a sixth aspect of the present invention, the method for polishing a substrate comprises the steps of: bonding a polishing cloth to a polishing table, polishing substrates with said polishing cloth, removing said polishing cloth, bonding another polishing-cloth to said polishing table, and polishing substrates.  
       [0018] According to a seventh aspect of the present invention, the method for polishing a substrate comprises the steps of: bonding a first polishing cloth to a polishing table, polishing substrates with said first polishing cloth, removing said first polishing cloth, bonding a second polishing cloth to said polishing table, polishing substrates with said second polishing cloth, removing said second polishing cloth, and bonding said first polishing cloth to said polishing table.  
       [0019] The above and other objects, features and advantages of the present invention will become more apparent from the following description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0020]FIG. 1 is a diagram schematically showing the arrangement of the turntable part of a conventional polishing apparatus.  
     [0021]FIG. 2 is a diagram schematically showing the arrangement of the turntable part of a polishing apparatus according to the present invention.  
     [0022]FIG. 3 is a diagram showing a structural example of heat-sensitive adhesive tape.  
     [0023]FIG. 4 is a diagram schematically showing the arrangement of the turntable part of a polishing apparatus according to the present invention.  
     [0024]FIG. 5( a ) is an external perspective view showing a structural example of a heating jig.  
     [0025]FIG. 5( b ) is a sectional view of the heating jig shown in FIG. 5( a ).  
     [0026]FIG. 6 is a diagram for describing a polishing cloth removing method according to the present invention.  
     [0027]FIG. 7 is a diagram for describing another polishing cloth removing method according to the present invention.  
     [0028]FIG. 8 is a diagram showing the relationship between the temperature and the peel strength of heat-sensitive adhesive tape.  
     [0029]FIG. 9 is a diagram schematically showing the arrangement of the top ring of a polishing apparatus according to the present invention.  
     [0030]FIG. 10 is a diagram showing a structural example of a jig usable for bonding and removing expendable components of the top ring according to the present invention. 
    
    
     EXPLANATION OF REFERENCE NUMERALS  
     [0031] 10 : turntable  
     [0032] 11 : polishing cloth  
     [0033] 12 : pressure-sensitive adhesive  
     [0034] 13 : heat-sensitive adhesive tape  
     [0035] 14 : motor  
     [0036] 15 : heating/cooling system  
     [0037] 16 : rotary joint  
     [0038] 20 : heating jig  
     [0039] 21 : collar  
     [0040] 22 : heating wire  
     [0041] 30 : cooling jig  
     [0042] 31 : collar  
     [0043] 32 : refrigerant system  
     [0044] 40 : top ring  
     [0045] 41 : substrate holding plate  
     [0046] 42 : bolt  
     [0047] 43 : retainer ring  
     [0048] 44 : recess  
     [0049] 45 : pressure ring  
     [0050] 46 : backing film  
     [0051] 47 : mounting flange  
     [0052] 48 : shaft  
     [0053] 49 : driving shaft flange  
     [0054] 50 : ball bearing  
     [0055] 51 : space  
     [0056] 52 : communicating hole  
     [0057] 60 : plate-shaped heater  
     [0058] 61 : heating wire  
     [0059] 62 : plug socket  
     DETAILED DESCRIPTION OF THE INVENTION  
     [0060] Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 2 is a diagram showing a structural example of the turntable part of a polishing apparatus according to the present invention. As illustrated in the figure, a polishing cloth  11  is bonded to the top surface of a turntable  10  with a piece of heat-sensitive adhesive tape  13  interposed between the polishing cloth  11  and the top surface of the turntable  10 . It should be noted that reference numeral  14  denotes a motor for rotating the turntable  10  in the direction of the arrow A. As shown in FIG. 3, the heat-sensitive adhesive tape  13  comprises a PET (polyethylene terephthalate) film  13 - 1  and a heat-sensitive adhesive  13 - 2  applied to both sides of the PET film  13 - 1 .  
     [0061] The heat-sensitive adhesive  13 - 2  on both sides of the PET film  13 - 1  constituting the heat-sensitive adhesive tape  13  is an adhesive known as “Intelimer” (registered trademark of Landec Corporation, U.S.A.). Intelimer is an adhesive that undergoes a reversible change from a crystalline state to an amorphous state according to changes in temperature of the outside. As shown in FIG. 8, one type of Intelimer functions as an ordinary adhesive (exhibiting high peel strength) below a preset temperature (switching temperature) Ts. However, above the set temperature Ts, the peel strength decreases, so that the Intelimer tape can be peeled off easily. There is another type of Intelimer that acts reversely to the above. That is, this type of Intelimer functions as an ordinary adhesive above a preset temperature Ts. However, below the set temperature Ts, the peel strength decreases, so that the Intelimer tape can be peeled off easily. In this embodiment, Intelimer tape available from Nitta Corporation (Japan) is used as the heat-sensitive adhesive tape  13 .  
     [0062] Thus, the polishing cloth  11  may be bonded to the top surface of the turntable  10  by using a heat-sensitive adhesive tape  13  in which the heat-sensitive adhesive  13 - 2  functions as an ordinary adhesive below the set temperature but decreases in peel strength above the set temperature. To bond the polishing cloth  11  to the top surface of the turntable  10  by using such a heat-sensitive adhesive tape  13 , for example, the top surface of the turntable  10  is heated to a predetermined temperature higher than the set temperature, and the polishing cloth  11  is placed over the top surface of the turntable  10  with the heat-sensitive adhesive tape  13  interposed therebetween. In this case, because the top surface temperature of the turntable  10  is higher than the set temperature, the peel strength of the heat-sensitive adhesive  13 - 2  is low, which facilitates the alignment of the polishing cloth  11  and the heat-sensitive adhesive tape  13  on the top surface of the turntable  10 . In this state, the turntable  10  is cooled down to a predetermined temperature below the set temperature (e.g. to a temperature lower than the set temperature by 10° C. or more), and the upper surface of the polishing cloth  11  is pressed with a rubber roller or the like. Thus, the polishing cloth  11  can be bonded to the top surface of the turntable  10  with the heat-sensitive adhesive tape  13  interposed therebetween.  
     [0063] The heat-sensitive adhesive  13 - 2  can be kept in a state where the peel strength is high by maintaining the temperature of the turntable  10  in use at a level lower than the set temperature by a predetermined temperature. Therefore, there is no possibility of the polishing cloth  11  undesirably separating from the turntable  10 . To remove the polishing cloth  11  from the turntable  10 , the turntable  10  is heated to a predetermined temperature above the set temperature (e.g. to a temperature higher than the set temperature by 10° C. or more). Consequently, the peel strength of the heat-sensitive adhesive  13 - 2  decreases. Therefore, the polishing cloth  11  can be readily removed from the turntable  10 . In a case where the heat-sensitive adhesive  13 - 2  is adhesive above a set temperature but non-adhesive below the set temperature, the temperature of the turntable  10  in use is maintained at a predetermined temperature above the set temperature. To remove the polishing cloth  11 , the turntable  10  is cooled down to a predetermined temperature below the set temperature.  
     [0064]FIG. 4 is a diagram showing a structural example of the turntable part of a polishing apparatus according to the present invention. As illustrated in the figure, a heating/cooling system  15  for heating or cooling is provided in the turntable  10  through a rotary joint  16 . The heating/cooling system  15  is supplied with a heating heat transfer medium Q 1  or a cooling refrigerant Q 2  from a heat transfer medium source or a refrigerant source (not shown). Thus, the heating heat transfer medium Q 1  or the cooling refrigerant Q 2  can be circulated through the heating/cooling system  15 .  
     [0065] In the case of using the heat-sensitive adhesive tape  13  in which the heat-sensitive adhesive  13 - 2  is adhesive above a set temperature but non-adhesive below the set temperature, when the polishing cloth  11  is to be bonded, the cooling refrigerant Q 2  is circulated through the heating/cooling system  15  to cool and maintain the top surface of the turntable  10  at a predetermined temperature below the set temperature. In this state, the polishing cloth  11  is placed over the top surface of the turntable  10  with the heat-sensitive adhesive tape  13  interposed therebetween. In this state, the peel strength of the heat-sensitive adhesive  13 - 2  is low. Therefore, it is easy to perform alignment of the heat-sensitive adhesive tape  13  and the polishing cloth  11 . Upon completion of the alignment, the circulation of the cooling refrigerant Q 2  is stopped to allow the turntable  10  to rise in temperature. Alternatively, the heating heat transfer medium Q 1  is circulated through the heating/cooling system  15  to raise the temperature of the turntable  10  positively. By doing so, the temperature of the turntable  10  is raised to a predetermined level above the set temperature. This allows the heat-sensitive adhesive  13 - 2  to exhibit adhesiveness (tackiness). Therefore, the polishing cloth  11  can be bonded by pressing the upper surface of the polishing cloth  11  with a rubber roller or the like.  
     [0066] By setting the set temperature of the heat-sensitive adhesive  13 - 2  at a predetermined temperature lower than the working temperature of the turntable  10 , the polishing cloth  11  is kept bonded to the top surface of the turntable  10  by the strong adhesiveness of the heat-sensitive adhesive  13 - 2  during the substrate polishing process. Therefore, there is no possibility that the polishing cloth  11  may undesirably separate from the turntable  10 . When the polishing cloth  11  is to be temporarily removed and bonded again or to be replaced with another polishing cloth  11 , the cooling refrigerant Q 2  is circulated through the heating/cooling system  15  to cool the top surface of the turntable  10  to a predetermined temperature below the set temperature. Consequently, the heat-sensitive adhesive  132  loses its adhesiveness. Therefore, it becomes possible to remove the polishing cloth  11  easily.  
     [0067] In the case of using the heat-sensitive adhesive tape  13  in which the heat-sensitive adhesive  13 - 2  is non-adhesive above a set temperature but adhesive below the set temperature, when the polishing cloth  11  is to be bonded, the heating heat transfer medium Q 1  is circulated through the heating/cooling system  15  to heat the top surface of the turntable  10  to a predetermined temperature above the set temperature. In this state, the polishing cloth  11  is placed over the top surface of the turntable  10  with the heat-sensitive adhesive tape  13  interposed therebetween. In this state, the heat-sensitive adhesive  13 - 2  is non-adhesive. Therefore, it is easy to perform alignment of the heat-sensitive adhesive tape  13  and the polishing cloth  11 . Upon completion of the alignment, the circulation of the heating heat transfer medium Q 1  is stopped to allow the turntable  10  to lower in temperature. Alternatively, the cooling refrigerant Q 2  is circulated through the heating/cooling system  15  to lower the temperature of the turntable  10  positively. By doing so, the temperature of the turntable  10  is lowered to a predetermined level below the set temperature. This allows the heat-sensitive adhesive  13 - 2  to exhibit adhesiveness. Therefore, the polishing cloth  11  can be bonded by pressing the upper surface of the polishing cloth  11  with a rubber roller or the like.  
     [0068] By setting the set temperature of the heat-sensitive adhesive  13 - 2  at a predetermined temperature higher than the working temperature of the turntable  10 , the polishing cloth  11  is kept bonded to the top surface of the turntable  10  by the strong adhesiveness of the heat-sensitive adhesive  13 - 2  during the substrate polishing process. Therefore, there is no possibility that the polishing cloth  11  may undesirably separate from the turntable  10 . When the polishing cloth  11  is to be temporarily removed and bonded again or replaced with another polishing cloth  11 , the heating heat transfer medium Q 1  is circulated through the heating/cooling system  15  to heat the top surface of the turntable  10  to a predetermined temperature above the set temperature. Consequently, the peel strength of the heat-sensitive adhesive  13 - 2  decreases. Therefore, it becomes possible to remove the polishing cloth  11  easily.  
     [0069] The heating heat transfer medium Q 1  or the cooling refrigerant Q 2  may be supplied to the heating/cooling system  15  during the operation of the turntable  10  to maintain the top surface of the turntable  10  at a temperature above or below the set temperature of the heat-sensitive adhesive  13 - 2  at which the heat-sensitive adhesive  13 - 2  exhibits strong adhesiveness. During the suspension of the operation, the adhesiveness of the heat-sensitive adhesive  13 - 2  may be reduced.  
     [0070] In the example shown in FIG. 4, the heating/cooling system  15  for heating or cooling is provided in the turntable  10 . It should be noted, however, that the polishing cloth  11  bonded to the turntable  10  can also be removed by using a heating jig  20  as shown in FIGS.  5 ( a ) and  5 ( b ). That is, the heating jig  20  is in the shape of a disk having a geometry capable of covering the turntable  10 . The disk-shaped heating jig  20  has a collar  21  formed around the periphery thereof. The heating jig  20  has a heating wire  22  buried therein. The whole heating jig  20  can be heated by supplying a heating current to the heating wire  22  from an AC or DC power supply. It should be noted that FIG. 5( a ) is a perspective view showing the whole heating jig  20 , and FIG. 5( b ) is a sectional view of the heating jig  20 .  
     [0071] The process of removing the polishing cloth  11  from the top surface of the turntable  10  by using the heating jig  20  shown in FIGS.  5 ( a ) and  5 ( b ) will be described below with reference to FIG. 6. It is assumed that the heat-sensitive adhesive tape  13  used in this example has a heat-sensitive adhesive  13 - 2  that is non-adhesive above a set temperature but adhesive below the set temperature, and that the set temperature is a predetermined temperature above the working temperature of the turntable  10 . First, the polishing cloth  11  is bonded to the top surface of the turntable  10  at the working temperature with the heat-sensitive adhesive tape  13  interposed therebetween, and used for polishing substrates. When the polishing cloth  11  is to be temporarily removed and bonded again or to be replaced with another polishing cloth  11 , the heating jig  20  is put over the polishing cloth  11  on the turntable  10 , and the heating wire  22  is supplied with a heating current. Thus, the heating jig  20  heats up. Consequently, the heat-sensitive adhesive  13 - 2  of the heat-sensitive adhesive tape  13  loses its adhesiveness to become non-adhesive. In this state, the heating jig  20  is taken off, and the polishing cloth  11  is removed from the turntable  10 . Thus, the polishing cloth  11  can be removed from the turntable  10  easily with minimal removal force.  
     [0072] In the case of using the heat-sensitive adhesive tape  13  in which the heat-sensitive adhesive  13 - 2  is non-adhesive at a predetermined set temperature below the working temperature of the turntable  10  but adhesive above the set temperature, the polishing cloth  11  is bonded to the top surface of the turntable  10  at the working temperature with the heat-sensitive adhesive tape  13  interposed therebetween, and used for polishing substrates. When the polishing cloth  11  is to be temporarily removed and bonded again or to be replaced with another polishing cloth  11 , a cooling jig  30  is put over the polishing cloth  11 , as shown in FIG. 7 by way of example. The cooling jig  30  has a refrigerant system  32  buried therein for passing a cooling refrigerant Q 3  [the external geometry of the cooling jig  30  is almost the same as that of the heating jig  20  shown in FIGS.  5 ( a ) and  5 ( b ); the disk-shaped cooling jig  30  has a collar  31  formed around the periphery thereof]. Then, the refrigerant system  32  is supplied with the cooling refrigerant Q 3 . Thus, the heat-sensitive adhesive  13 - 2  of the heat-sensitive adhesive tape  13  is cooled down to a predetermined temperature below the set temperature and hence loses its adhesiveness to become non-adhesive. In this state, the cooling jig  30  is taken off, and the polishing cloth  11  is removed from the turntable  10 . Thus, the polishing cloth  11  can be removed from the turntable  10  easily with minimal removal force.  
     [0073] As has been stated above, the polishing cloth  11  is bonded to the top surface of the turntable  10  with the heat-sensitive adhesive tape  13  interposed therebetween. Therefore, the polishing cloth  11  can be bonded and removed easily by controlling the temperature of the turntable  10 . The use of the heating jig  20  or the cooling jig  30  allows the bonded polishing cloth  11  to be removed from the turntable  10  easily with minimal removal force. Accordingly, the replacement operation for the polishing cloth  11  is improved to a considerable extent. Consequently, it becomes unnecessary to perform the conventional troublesome removing operation using a special jig. In addition, it becomes possible to remove the polishing cloth  11  temporarily before the time for replacement and to reuse it later. For example, when the user wants to perform another polishing process in the course of use of the polishing cloth  11 , it is possible to remove the polishing cloth  11  temporarily, bond another kind of polishing cloth  11 , remove this polishing cloth  11  after the desired polishing process, and bond the first-removed polishing cloth  11  again to perform the previous polishing process.  
     [0074] The heat-sensitive adhesive tape  13  can be switched between the adhesive state and the non-adhesive state by selectively heating and cooling the turntable  10  by the use of the temperature control function of cooling water in the turntable  10 . However, in a case where such a switching operation cannot readily be implemented owing to some problems with the chiller equipment in the plant, the use of the heating jig  20  for heating the polishing cloth  11  allows the heat-sensitive adhesive tape  13  to be readily switched between the adhesive state and the non-adhesive state.  
     [0075] Although in the foregoing embodiment the present invention has been described with regard to the polishing apparatus using the turntable  10 , by way of example, the present invention is not necessarily limited to the polishing apparatus using the turntable  10 . The present invention is widely applicable to any polishing apparatus having a table with a polishing cloth bonded thereto, wherein an object to be polished is brought into contact with the surface of the polishing cloth on the table and polished by a relative motion between the polishing cloth and the object.  
     [0076] In the foregoing embodiment, the polishing cloth  11  is bonded to the top surface of the turntable  10  of the polishing apparatus with the heat-sensitive adhesive tape  13  interposed between the top surface of the turntable  10  and the polishing cloth  11 . However, the present invention is not necessarily limited to the described embodiment. For example, the present invention is also applicable to a backing film and a pressure ring that are bonded to a top ring. FIG. 9 is a sectional view showing a structural example of a top ring according to the present invention.  
     [0077] As shown in FIG. 9, the top ring  40  according to the present invention has a substrate holding plate  41  and a retainer ring  43  detachably secured to the outer peripheral portion of the substrate holding plate  41  with bolts  42 . A recess  44  for accommodating a substrate Wf is formed by the lower surface (substrate holding surface) of the substrate holding plate  41  and the retainer ring  43 . A pressure ring  45  is vertically movably provided around the substrate holding plate  41 . The substrate holding plate  41  has a backing film  46  bonded to the lower surface thereof. Further, the substrate holding plate  41  has a mounting flange  47  secured to the center of the upper surface thereof. The mounting flange  47  has a concave spherical surface  47   a.    
     [0078] A shaft  48  is disposed above the mounting flange  47 . The shaft  48  has a driving shaft flange  49  secured to the lower end thereof. The driving shaft flange  49  has a concave spherical surface  49   a.  A ball bearing  50  is interposed between the concave spherical surface  47   a  and the concave spherical surface  49   a.  A space  51  is formed between the substrate holding plate  41  and the mounting flange  47 . The space  51  can be selectively supplied with a vacuum or a fluid such as pressurized air or water. The substrate holding plate  41  has communicating holes  52  opening on the lower surface thereof. The communicating holes  52  are in communication with the space  51 . The backing film  46  also has through-holes formed at respective positions facing the communicating holes  52 . Thus, the upper surface of the substrate Wf can be held by a vacuum to the lower surface of the substrate holding plate  41  through the backing film  46 . It is also possible to supply a fluid such as a liquid or pressurized air to the upper surface of the substrate Wf.  
     [0079] The pressure ring  45  comprises a first pressure ring member  45   a  located at the lowermost position and made of alumina ceramics, and second and third pressure ring members  45   b  and  45   c  disposed above the first pressure ring member  45   a  and made of a stainless steel. The second and third pressure ring members  45   b  and  45   c  are connected to each other with bolts (not shown). The first pressure ring member  45   a  is bonded to the second pressure ring member  45   b.  The lower end of the first pressure ring member  45   a  forms a pressure surface  45   f  for pressing the polishing cloth  11  (see FIG. 2) bonded to the top surface of the turntable  10 .  
     [0080] In operation, a substrate Wf is held by suction to the lower surface of the backing film  46  bonded to the lower surface of the substrate holding plate  41  of the top ring  40  arranged as stated above. Then, the substrate Wf is pressed against the upper surface of the polishing cloth  11  on the turntable  10  shown in FIG. 2. In this state, the substrate Wf is polished by a relative motion between the substrate Wf and the polishing cloth  11  caused by the rotation of the top ring  40  about the shaft  48  and the rotation of the turntable  10 . The polishing operation causes the first pressure ring member  45   a  of the pressure ring  45  to wear out. Therefore, the first pressure ring member  45   a  needs to be replaced when it has worn out to a predetermined extent. The backing film  46  also wears out in the course of polishing a large number of substrates Wf. Therefore, the backing film  46  also needs to be replaced at a predetermined timing.  
     [0081] In this embodiment, the above-described heat-sensitive adhesive tape (not shown in FIG. 9) is used for the first pressure ring member  45   a  and the backing film  46 . More specifically, a piece of heat-sensitive adhesive tape is interposed between the first pressure ring member  45   a  and the second pressure ring member  45   b  of the pressure ring  45  to bond the first pressure ring member  45   a  to the lower surface of the second pressure ring member  45   b.  Further, a piece of heat-sensitive adhesive tape is interposed between the backing film  46  and the substrate holding plate  41  to bond the backing film  46  to the lower surface of the substrate holding plate  41 .  
     [0082] By using the heat-sensitive adhesive tape to bond the first pressure ring member  45   a  to the second pressure ring member  45   b  and also using the heat-sensitive adhesive tape to bond the backing film  46  to the lower surface of the substrate holding plate  41 , the first pressure ring member  45   a  and the backing film  46  can be bonded and removed extremely easily by the temperature control of the heat-sensitive adhesive tape as in the case of the above.  
     [0083] The bonding and removing operation may be carried out by using a plate-shaped heater  60  having a heating wire  61  as shown in FIG. 10 by way of example. That is, the plate-shaped heater  60  is brought into contact with the backing film  46  or the first pressure ring member  45   a,  and the heating wire  61  is supplied with a heating current through a plug socket  62  to heat the backing film  46  or the first pressure ring member  45   a,  thereby allowing the backing film  46  or the first pressure ring member  45   a  to be bonded or removed easily.  
     [0084] It should be noted that the structural example of the top ring is not necessarily limited to the above. For example, the present invention is similarly applicable to a top ring employing a retainer ring directly retaining the side surface of a substrate.  
     [0085] Although in the foregoing embodiments the present invention has been described with regard to the operation of bonding and removing the backing film  46 , the first pressure ring member  45   a  and the polishing cloth  11 , by way of example, it should be noted that the present invention is not necessarily limited thereto but may be used for bonding and removing various expendable replacement components to be bonded to the top ring or the polishing table of the polishing apparatus.  
     [0086] As has been stated above, the present invention provides various advantageous effects as stated below.  
     [0087] According to the first and second aspects of the present invention, pieces of heat-sensitive adhesive tape are interposed between expendable replacement components such as a backing film, a pressure ring and a polishing cloth on the one hand and the top ring and the polishing table on the other to bond the expendable replacement components to the top ring and the polishing table. The heat-sensitive adhesive tape has the nature of switching between a non-adhesive state and a adhesive state according to whether the temperature thereof is higher or lower than a predetermined set temperature. Therefore, the expendable replacement components can be bonded and removed easily by heating or cooling the heat-sensitive adhesive tape above or below the set temperature. Particularly, when the heat-sensitive adhesive tape is made non-adhesive by heating or cooling, the expendable replacement components can be removed easily with minimal removal force. Further, because the removal force is minimized, the expendable replacement components can be removed without being damaged. Accordingly, it becomes possible to remove the expendable replacement components temporarily before the time for replacement and to reuse them later.  
     [0088] According to the third to fifth aspects of the present invention, pieces of heat-sensitive adhesive tape are interposed between expendable replacement components such as a backing film, a pressure ring and a polishing cloth on the one hand and the top ring and the polishing table on the other, and the heat-sensitive adhesive tape is switched between a non-adhesive state and a adhesive state by heating or cooling it above or below a set temperature. Therefore, it is easy to bond and remove the expendable replacement components. Particularly, when the heat-sensitive adhesive tape is made non-adhesive, the expendable replacement components can be removed easily with minimal removal force. Accordingly, it is possible to obtain advantageous effects similar to those obtained by the arrangement according to the first and second aspects of the present invention.  
     [0089] According to the fourth aspect of the present invention, the heat-sensitive adhesive tape can be made non-adhesive easily by using a jig for heating or cooling the heat-sensitive adhesive tape.  
     [0090] It should be noted that the present invention is not necessarily limited to the foregoing embodiments but can be modified in a variety of ways without departing from the gist of the present invention.