JP2015126001A - Wafer polishing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce running cost by eliminating the need for a consumable article such as a retainer ring and to uniformly polish a wafer surface.SOLUTION: A wafer polishing device comprises: a rotary body 12; a rotation shaft 13 arranged so as to be coaxial with the rotary body, rotated integrally with the rotary body, and provided so as to be movable relative to the rotary body in the direction of the rotation axis thereof; a pressing member 24 that presses the rotation shaft toward its one end relative to the rotary body; a work chuck 15 supported at the one end of the rotation shaft so as to swing via a spherical bearing mechanism 30 and also holding a wafer W; an air bag 31 interposed between the rotary body and work chuck. The spherical bearing mechanism is set such that the swing center is located within the thickness of the work chuck. When air is introduced into the air bag, the work chuck relatively move away from the rotary body against the pressing force of the pressing member, and presses the wafer, held by the work chuck, against a polishing pad 6.

Description

  The present invention relates to a wafer polishing apparatus, and more particularly to a wafer polishing apparatus for polishing a semiconductor wafer by chemical mechanical polishing (CMP).

In recent years, IC microfabrication has progressed, and IC patterns are formed over multiple layers. In such an IC structure, it is inevitable that a certain degree of unevenness occurs on the surface of the layer on which the pattern is formed.
During such pattern formation, a wafer polishing apparatus (CMP apparatus) using a CMP method is used to polish the wafer in order to flatten the irregularities generated on the surface of the layer on which the pattern is formed.

  As a wafer polishing apparatus, a disk-shaped polishing surface plate having a polishing pad (polishing cloth) attached to the surface, a plurality of polishing heads that hold the back surface of the wafer to be polished and bring the wafer surface into contact with the polishing pad, and these A head drive mechanism that rotates the polishing head relative to the polishing surface plate, and has a structure that polishes the wafer by supplying slurry, which is an abrasive, between the polishing pad and the wafer is generally widely known. It has been.

  As an example of this type of wafer polishing apparatus, when the wafer surface held by the polishing head is pressed against the polishing pad, an air layer is formed between the polishing head and the wafer, and air is supplied to this air layer. Therefore, a structure in which the wafer is pressed against the polishing pad with a predetermined pressing force using air pressure has been proposed. And in this wafer polisher, the retainer ring is arrange | positioned on the radial direction outer side of a wafer so that the air leakage from an air chamber may become an appropriate quantity (for example, refer patent document 1).

JP 2010-42459 A

  In the above-described wafer polishing apparatus, it is inevitable that the retainer ring contacts the polishing pad, and not only the wafer but also this retainer ring is polished by the polishing pad. For this reason, it is necessary to replace the retainer ring at regular intervals. However, since the retainer ring is made of a special material so as to be flexible as appropriate, it is relatively expensive, so changing such a retainer ring at regular intervals increases the lining strike. It was one of the factors.

In addition, in this type of wafer polishing apparatus, when the wafer surface is pressed against the polishing pad, the wafer is held so that the entire surface of the wafer can be pressed against the polishing pad with a uniform pressing force as much as possible. There is a type of supporting a work chuck to be swingable with respect to a chuck support.
However, in the conventional wafer polishing apparatus of this system, since the swing center of the work chuck is set at a position far away from the processing surface of the wafer, if the tilt angle of the work chuck increases. The rotation center position of the wafer is decentered with respect to the polishing surface plate, which causes an unnecessary moment when the wafer is pressed against the polishing pad and polished, resulting in polishing the wafer surface. There was a problem of unevenness.

  The present invention has been made under such a background. By eliminating consumables such as retainer rings, the running cost can be reduced, and the wafer surface can be uniformly polished. It is an object to provide a wafer polishing apparatus.

  In order to solve the above-described problems, a wafer polishing apparatus according to the present invention includes a rotator, and is disposed coaxially with the rotator and rotates integrally with the rotator, and the rotation axis of the rotator is A rotating shaft provided so as to be relatively movable in the direction, a biasing member that biases the rotating shaft toward one end with respect to the rotating body, and swings on the other end side of the rotating shaft via a spherical bearing mechanism A work chuck that can be supported and holds a wafer to be polished, and an air bag interposed between the rotating body and the work chuck. The spherical bearing mechanism has a swing center. The work chuck is set to be positioned within the thickness of the work chuck including the wafer, and when the air is introduced into the airbag, the work chuck is separated from the rotating body against the urging force of the urging member. To do To move relatively, characterized in that pressing the wafer held on the workpiece chuck to the polishing pad.

  According to the present invention, the wafer is first held by the work chuck, and air is introduced into the airbag in this state. Due to the pressure of the air introduced into the air bag, the air chuck moves relative to the direction away from the rotating body against the urging force of the urging member that urges the rotating shaft, and the held wafer is pressed against the polishing pad. Thereby, the wafer is polished. At this time, the air is only introduced into the air bag which is a closed space, and there is no need to use a retainer ring which is a consumable member for adjusting air leakage. For this reason, management for preparing a retainer ring for replacement in advance and management of the replacement timing of the retainer ring become unnecessary.

  Further, when the wafer held by the work chuck is pressed against the polishing pad, the work chuck is swingably supported by the rotating shaft via the spherical bearing mechanism. Since it is set so as to be positioned within the thickness of the work chuck including the work chuck, even when the inclination angle of the work chuck is increased, the amount of the rotation center position of the wafer being eccentric with respect to the polishing surface plate is very small. As a result, an unnecessary moment is hardly generated when the wafer is pressed against the polishing pad and polished, and as a result, the wafer surface can be polished almost uniformly.

The spherical bearing mechanism includes an inner convex spherical surface formed on the rotating shaft, an outer concave spherical surface formed on the work chuck, and a plurality of spheres interposed between the inner convex spherical surface and the outer concave spherical surface. It is preferable to comprise.
In this case, the inner convex spherical surface and the outer concave spherical surface are in contact with each other via the spherical body, and thus, support for extremely small friction is possible when the work chuck is supported in a swingable manner.

In the spherical bearing mechanism, it is preferable that the center of oscillation is set at a position flush with the work surface of the wafer held by the work chuck.
In this case, even if the tilt angle of the work chuck becomes large, the rotation center position of the wafer is not decentered with respect to the polishing surface plate. As a result, no unnecessary moment is generated when the wafer is pressed against the polishing pad and polished, and as a result, the wafer surface can be polished more uniformly.

It is preferable that the air bag includes a ring-shaped flexible film disposed on a surface of the rotating body facing the work chuck and radially outside the rotating shaft.
In this case, since the work chuck receives a pressing force by the air pressure so as to be separated from the rotating body via the ring-shaped flexible film, the work chuck receives a uniform pressing force over the entire circumferential direction. Accordingly, the wafer held by the work chuck can be uniformly pressed against the polishing pad over the entire circumferential direction.

It is preferable that the ring-shaped flexible film is arranged with the center in the width direction outside the spherical bearing mechanism.
Because it is possible to widen the pressing area when pressing the work chuck toward the polishing pad in the direction away from the rotating body, and from the outside than the spherical bearing mechanism when pressing the work chuck toward the polishing pad, The response time when the workpiece chuck is swung following the unevenness of the surface of the polishing pad can be shortened.

It is preferable that a rotation transmission mechanism for transmitting the rotation of the rotation shaft to the work chuck is provided.
The rotational force of the rotary shaft is transmitted to the work chuck via the rotation transmission mechanism, and the work chuck rotates. Accordingly, the wafer held by the work chuck can be forcibly rotated on the polishing pad.

The work chuck is preferably provided with a cooling mechanism.
As the wafer is polished, frictional heat is generated. This frictional heat can be suitably removed by the cooling mechanism. For this reason, it is possible to avoid the temperature of the wafer and the work chuck from being increased more than necessary due to frictional heat.

  According to the wafer polishing apparatus of the present invention, it is possible to reduce running costs by eliminating consumables such as retainer rings, and to provide a wafer polishing apparatus capable of polishing the wafer surface uniformly. Let it be an issue.

1 is an overall structural diagram of an embodiment of a wafer polishing apparatus according to the present invention. 1 is a longitudinal sectional view of a polishing head of an embodiment of a wafer polishing apparatus according to the present invention. (A), (b) is a figure showing the effect | action of the spherical bearing mechanism of the wafer polisher which concerns on this invention, respectively, Comprising: It is detail drawing of the III circle part of FIG. It is a bottom view of the chuck | zipper main body of embodiment of the wafer grinding | polishing apparatus which concerns on this invention. It is a longitudinal cross-sectional view when the grinding | polishing head of embodiment of the wafer grinding | polishing apparatus which concerns on this invention is cut | disconnected in the location different from FIG.

Hereinafter, embodiments of a wafer polishing apparatus according to the present invention will be described with reference to the drawings. 1 is an overall structural view of an embodiment of a wafer polishing apparatus according to the present invention, FIG. 2 is a longitudinal sectional view of a polishing head of an embodiment of a wafer polishing apparatus according to the present invention, and FIGS. It is a figure showing the effect | action of the spherical bearing mechanism of the wafer polisher based on this invention, Comprising: It is detail drawing of the III circle part of FIG.
As shown in FIG. 1, the wafer polishing apparatus 1 mainly includes a platen 2 and a polishing head 3.

The platen 2 is formed in a disk shape, and a support shaft 4 is connected to the center of the lower surface thereof, and rotates in a predetermined direction by driving a motor 5 connected to the lower end of the support shaft 4. A polishing pad 6 is adhered to the upper surface of the platen 2, and a slurry that is a mixture of an abrasive and a chemical is supplied onto the polishing pad 6 from a nozzle (not shown).
The polishing head 3 is appropriately moved between a platen 2, a wafer standby position where a wafer before polishing is placed, and a wafer storage position where a wafer after polishing is placed by a moving mechanism (not shown). .

  As shown in FIG. 2, the polishing head 3 is mainly disposed on the rotating body 12 supported by the support portion 10 of the apparatus main body, is coaxial with the rotating body 12, and rotates integrally with the rotating body 12. The rotary shaft 13 is provided so as to be movable relative to the rotary body 12 in the direction of the rotational axis l, that is, in the vertical direction, and is supported on the other end side of the rotary shaft 13 through a spherical bearing mechanism 30 so as to be swingable. And a work chuck 15 for holding a wafer to be polished.

  The rotating body 12 is rotatably supported via the bearing 11 on the support portion 10 that is movable in the vertical direction. The rotating body 12 includes a rotating gear portion 17 at an upper portion thereof, and rotation is transmitted from a rotation driving means (not shown) via the rotating gear portion 17. A cylindrical rotating body 18 is provided at the center of the rotating body 12, and the rotating body 18 engages with the bearing 11. A disc-shaped rotating flat plate portion 19 is provided below the rotating body 12, and the rotating flat plate portion 19 presses the work chuck 15 downward via an air bag 31 described later.

  The rotary shaft 13 includes an upper rotary shaft portion 21 that is spline-fitted with a support portion 18 a provided inside the rotary main body portion 18 so as to be vertically movable and integrally rotated, and a lower end of the upper rotary shaft portion 21. And a flat plate portion 23 connected to the lower end of the connection plate portion 22. A spring receiver 21a is provided on the upper portion of the upper rotating shaft portion 21, and the rotating shaft 13 is biased to one end side, that is, upward by a compression spring 24 interposed between the spring receiver 21a and the support portion 18a. The

  The work chuck 15 includes a chuck main body 26 formed in a disk shape and a ring-shaped upper plate portion 27 provided on the upper side of the chuck main body 26. The spherical bearing mechanism 30 is provided between the upper plate portion 27 and the flat plate portion 23.

As shown in FIGS. 3A and 3B, the spherical bearing mechanism 30 includes an outer concave spherical surface 30 a provided on the inner peripheral portion of the upper plate portion 27 and an inner side provided on the outer peripheral portion of the flat plate portion 23. A convex spherical surface 30b, and a plurality of spherical bodies 30c interposed between the outer concave spherical surface 30a and the inner convex spherical surface 30b. The swing center P of the work chuck by the spherical bearing mechanism 30 is set so as to be flush with the work surface of the wafer W held by the work chuck 15. That is, the center of curvature of the outer concave spherical surface 30a and the inner convex spherical surface 30b is the same position as the processing surface of the wafer W held by the work chuck 15, more specifically, the center position of the processing surface of the wafer W. It is set to become.
In addition, you may make it the structure provided with the retainer which hold | maintains the spherical body 30c so that the spherical body 30c may not drop | omit from the clearance gap between the outer side concave spherical surface 30a and the inner side convex spherical surface 30b as needed.

  As shown in FIG. 2, when an air bag 31 is interposed between the rotary plate portion 19 of the rotating body 12 and the upper plate portion 27 of the work chuck 15, and air of a predetermined pressure is introduced into the air bag 31. In addition, the work chuck 15 is relatively moved in the direction away from the rotating body 12, that is, downward in the figure, against the urging force of the compression spring 24. The airbag 31 is formed by forming a ring-shaped groove 31a on the lower surface of the rotating flat plate portion 19 and attaching a ring-shaped flexible film 31b by a fixing ring 32 so as to close the groove 31a from below. Yes.

  The ring-shaped airbag 31 is arranged concentrically with the rotation axis 1 of the rotating body 12. The ring-shaped air bag 31, more specifically, the ring-shaped flexible film 31 b, is arranged so that the center in the width direction is outside the spherical bearing mechanism 30.

  Further, the air bag 31 has an air passage 33 having a vertical hole 33a penetrating the rotary gear portion 17 and the rotary main body portion 18 and a crank-shaped hole 33b formed in the rotary flat plate portion 19 so as to be connected to the vertical hole 33a. , Compressed air of a predetermined pressure is supplied from an air supply source (not shown).

  A rotation transmission mechanism 35 that transmits the rotation of the rotation shaft 13 to the work chuck 15 is interposed between the rotation shaft 13 and the work chuck 15. The rotation transmission mechanism 35 is constituted by an alternator joint constituted by one coupling piece 35 a provided on the lower surface of the connecting plate portion 22 and another coupling piece 35 b provided on the upper surface of the chuck body 26. . Accordingly, even when the axis of the rotary shaft 13 and the work chuck 15 are slightly deviated from each other, the rotation of the rotary shaft 13 is transmitted to the work chuck 15.

4 is a bottom view of the work chuck of the embodiment of the wafer polishing apparatus according to the present invention, and FIG. 5 is a longitudinal section of the polishing head of the embodiment of the wafer polishing apparatus according to the present invention when cut at a location different from FIG. FIG.
As shown in FIG. 4, a cooling mechanism 36 for cooling the work chuck 15 is provided below the chuck body 26. The cooling mechanism 36 includes a cooling water passage 37 including a spiral groove 37a formed over the entire lower surface of the chuck body 26 and a cover 37b that covers the spiral groove 37a from below. In the cooling water passage 37, a cooling water inlet portion 38 is provided at one end of the outer peripheral portion of the chuck body 26. The cooling water introduced from the cooling water inlet portion 38 gradually reaches the center side of the chuck body 26 along the spiral groove 37a along the circumferential direction, is folded back at the center portion, and is again swirled groove 37a. The chuck body 26 gradually reaches the outer peripheral side of the chuck body 26 along the circumferential direction, and finally reaches the cooling water outlet 39 provided at the other end of the outer periphery of the chuck body. In the chuck body 26, the cooling water inlet portion 38 and the cooling water outlet portion 39 are disposed outside the spherical bearing mechanism 30 in order to avoid interference with the spherical bearing mechanism 30.

  As shown in FIG. 5, the cooling water inlet portion 38 has a vertical hole 40 a penetrating the rotary gear portion 17 and the rotary main body portion 18, and a crank-like shape formed in the rotary flat plate portion 19 so as to be connected to the vertical hole 40 a. A cooling water forward path 40 having a hole 40 b is formed, and cooling water is supplied from a cooling water supply source (not shown) to the cooling water inlet portion 38 through the cooling water forward path 40. The supplied cooling water passes through the cooling water passage 37 and then reaches the cooling water outlet 39. The cooling water has a crank-shaped hole 41b formed in the rotating flat plate portion 19 and a cooling water return passage having a vertical hole 41a penetrating the rotating gear portion 17 and the rotating main body portion 18 so as to be connected to the crank-shaped hole 41b. It passes 41 and returns to the cooling water supply source which is not illustrated.

  A recess 26a is formed on the lower surface of the chuck body 26, and a porous plate 43 having air permeability is accommodated in the recess 26a. The porous plate 43 has a wafer suction path 44 having a vertical hole 44a penetrating the rotary gear portion 17 and the rotary main body portion 18 respectively, and a crank-shaped hole 44b formed in the rotary flat plate portion 19 so as to be connected to the vertical hole 44a. Via a vacuum source such as a vacuum pump. When the vacuum source is driven, the porous plate 43 is depressurized, and the wafer W to be polished can be sucked and held on the lower surface of the porous plate 43.

An air passage 33 that supplies compressed air to the airbag 31, a cooling water forward passage 40 that communicates with a cooling mechanism, a cooling water return passage 41, and a wafer suction passage 44 that decompresses the porous plate 43 are shown in FIGS. As seen in the cross-sectional view, it seems that the rotary shaft 13 and the rotary flat plate portion 19 are formed at the same position in the radial direction from the center of rotation (rotation axis 1). For example, at 90 ° intervals, and are arranged so as not to interfere with each other.
Reference numeral 45 denotes a dust cover that is provided on the outer peripheral portions of the rotating flat plate portion 19 and the upper plate portion 27 that face each other and prevents entry of dust and the like into the work chuck 15.

  Next, the operation of the wafer polishing apparatus 1 configured as described above will be described. First, the polishing head 3 is moved to a predetermined position on the wafer W before polishing, which is waiting, by a moving mechanism (not shown). Then, a vacuum source (not shown) attached to the polishing head 3 is operated to depressurize the porous plate 43 through the wafer suction path 44, and the wafer W before polishing is sucked by the suction action of the lower surface of the porous plate 43. Hold. Thereafter, the polishing head 3 is carried to a predetermined height position on the platen 2 by the moving mechanism while the wafer W is sucked and held.

  Next, a compressed air supply source (not shown) is operated to supply compressed air to the airbag 31 via the air passage 33 to inflate the airbag 31. When the air bag 31 is inflated, the work chuck 15 is pressed away from the rotating body 12, that is, downward, and the work chuck 15 is moved downward together with the rotary shaft 13 against the urging force of the compression spring 24. Let Accordingly, the wafer W sucked and held on the lower surface of the work chuck 15 can be pressed against the polishing pad 6.

  In this state, the platen 2 and the polishing head 3 are rotated in advance as shown in FIG. 1, and slurry is supplied from a nozzle (not shown) onto the rotating polishing pad 6 so that a predetermined conductive film on the wafer W is obtained. Etc. are polished.

Here, although the polishing platen on which the polishing pad 6 is placed is inevitably caused by some irregularities and inclinations due to production errors and the like, the rotating shaft 13 is swung so as to follow these irregularities and inclinations. The work chuck 15 supported so as to be movable is in close contact with the upper surface of the polishing pad 6 while swinging as needed.
At this time, since the swing center P of the work chuck 15 is set at a position flush with the surface to be processed of the wafer W held by the work chuck 15, a polishing surface plate as shown in FIG. Even when the inclination angle of the work chuck 15 increases following the unevenness and inclination of the wafer W, the rotation center position of the wafer W does not decenter with respect to the polishing surface plate. As a result, an unnecessary moment does not occur when polishing the wafer W, and as a result, the wafer surface can be polished to a uniform smooth surface.

  Further, when supplying compressed air for pressing the wafer W against the polishing pad 6, the compressed air is only introduced into the air bag 31 that is a closed space through the air passage 33, and is consumed for adjusting air leakage. There is no need to use a retainer ring as a member. For this reason, management for preparing a retainer ring for replacement in advance and management of the replacement timing of the retainer ring are unnecessary, and the running cost can be greatly reduced.

  Further, the airbag 31 when pressing the wafer against the polishing pad 6 has the center in the width direction arranged outside the spherical bearing mechanism 30. Therefore, the pressing area when pressing the work chuck 15 downward is reduced. Since it can be widely used and the work chuck 15 can be pressed from the outer peripheral side of the spherical bearing mechanism 30, the response time when the work chuck is swung following the unevenness and inclination of the surface of the polishing pad 6 is shortened. can do. As a result, the wafer surface can be further polished to a uniform smooth surface.

  When the rotating body 12 rotates, the rotation of the rotating body 12 is transmitted to the rotating shaft 13 that is spline-fitted with the support portion 18a of the rotating main body portion 18, and the rotation transmitting mechanism that is an Oldham coupling from the rotating shaft 13. It is further transmitted to the work chuck 15 via 35. For this reason, although the work chuck 15 is supported by the rotary shaft 13 so as to be able to swing, the work chuck 15 rotates integrally with the rotating body 12. Therefore, the wafer W can be rotated by the forced rotational force transmitted from the rotating body 12 without causing the wafer W to rotate due to friction with the polishing pad 6.

Simultaneously with the supply of compressed air to the air bag 31, the cooling water is supplied from the cooling supply source to the cooling water passage 37 through the cooling water forward path 40.
Friction heat is generated when the wafer W is polished. This friction heat can be removed by the cooling water supplied to the cooling water passage 37. For this reason, it is possible to prevent the temperature of the wafer W and the work chuck 15 from rising more than necessary due to frictional heat.

When the polishing is completed, the supply of compressed air and the supply of cooling water are stopped. The air bag 31 returns to its original size, and accordingly, the work chuck 15 is raised together with the rotary shaft 13 to a predetermined height by the urging force of the compression spring 24.
Thereafter, a moving mechanism (not shown) is operated to carry the polished wafer together with the polishing head 3 to the wafer storage position.

The wafer polishing apparatus of the present invention is not limited to the above-described embodiment, and it is possible to change or improve the components without departing from the gist of the present invention.
In the above embodiment, the swing center P of the spherical bearing mechanism 30 that supports the work chuck 15 is set at the same position as the work surface of the wafer W held by the work chuck 15. The swing center P may be slightly shifted upward without being moved. That is, the swing center P may be set so as to be positioned within the thickness of the work chuck 15 including the wafer W.

  In the embodiment, the compression spring 24 is used as an urging member that urges the rotary shaft 13 upward. However, the urging member is not limited to this, and an elastic member such as a tension spring or rubber is used. Or a structure using compressed air or the like.

  Moreover, in the said embodiment, from the ring-shaped groove | channel 31a formed in the lower surface of the rotation flat plate part 19 as the airbag 31, and the ring-shaped flexible film 31b attached so that this groove | channel 31a might be plugged up from the lower side. However, the airbag 31 is not limited to this, and may be a bag made of a ring-shaped elastic material.

  DESCRIPTION OF SYMBOLS 1 Wafer polisher, 2 Platen, 3 Polishing head, 6 Polishing pad, 11 Bearing, 12 Rotating body, 13 Rotating shaft, 15 Work chuck, 19 Rotating flat plate part, 24 Compression spring (biasing member), 30 Spherical bearing mechanism, 30a outer concave spherical surface, 30b inner convex spherical surface, 30c sphere, 31 air bag, 31a ring-shaped groove, 31b ring-shaped flexible film, 33 air passage, 35 rotation transmission mechanism, 36 cooling mechanism, W wafer, P swing Center, 1 axis of rotation.

Claims (7)

A rotating body,
A rotating shaft that is arranged coaxially with the rotating body and rotates integrally with the rotating body and is relatively movable in the direction of the rotation axis with respect to the rotating body;
An urging member for urging the rotating shaft toward one end with respect to the rotating body;
A work chuck that is supported on the other end of the rotating shaft through a spherical bearing mechanism so as to be swingable and holds a wafer to be polished;
An air bag interposed between the rotating body and the work chuck;
The spherical bearing mechanism is set so that its swing center is located within the thickness of the work chuck including the wafer,
When air is introduced into the air bag, the work chuck moves relative to the rotating body against the urging force of the urging member, and the wafer held by the work chuck is removed from the polishing pad. A wafer polishing apparatus that is pressed against the wafer.   The spherical bearing mechanism includes an inner convex spherical surface formed on the rotating shaft, an outer concave spherical surface formed on the work chuck, and a plurality of spheres interposed between the inner convex spherical surface and the outer concave spherical surface. The wafer polishing apparatus according to claim 1, comprising:   The wafer polishing apparatus according to claim 1, wherein the spherical bearing mechanism has a swing center set at a position flush with a surface to be processed of the wafer held by the work chuck. .   The said airbag is provided with the ring-shaped flexible film | membrane arrange | positioned on the surface facing the said work chuck | zipper of the said rotary body, and the radial direction outer side centering on the said rotating shaft. The wafer polisher as described in any one of -3.   5. The wafer polishing apparatus according to claim 4, wherein the ring-shaped flexible film has a center in the width direction arranged outside the spherical bearing mechanism.   The wafer polishing apparatus according to claim 1, further comprising a rotation transmission mechanism that transmits rotation of the rotation shaft to the work chuck.   The wafer polishing apparatus according to claim 1, wherein the work chuck is provided with a cooling mechanism.

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