JP2002144222A - Polishing head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polishing head capable of excellently polishing a wafer. SOLUTION: This polishing head 11 is provided with a disc-shaped carrier 16 for holding a surface of the wafer W on a lower surface and an annular retainer ring 17 which is concentrically arranged on an outer periphery of the carrier 16 and locks an outer periphery of the wafer W held by the carrier 16 on an inner peripheral surface 17a, abutting on the polishing pad 4 at the time of polishing. A first flow passage 32 leading from an upper surface 16b of the carrier 16 to a substantial center of a lower surface 16c is formed as a flow passage for supplying slurry or washing liquid between the wafer W and the polishing pad 4 through a through hole P formed at a substantial center of the wafer W in the carrier 16. The first flow passage 32 is connected to a slurry/washing liquid supplying mechanism 31 for selectively supplying either one of slurry or washing liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to polishing a surface of a material to be polished having a flat surface, such as a virgin silicon wafer, a semiconductor wafer in a semiconductor manufacturing process, a hard disk substrate, a liquid crystal substrate, or an optical component such as a lens. And a polishing head applied to the apparatus.

[0002]

2. Description of the Related Art In recent years, the miniaturization of patterns accompanying the high integration of semiconductor wafers has been progressing. In particular, since the formation of fine patterns of a multilayer structure can be performed easily and surely, the production of semiconductor wafers during the manufacturing process is difficult. It has become important to make the surface as flat as possible. For example, a pattern is formed using optical lithography, but as the pattern becomes finer, the depth of focus of optical lithography becomes shallower. In order to ensure pattern accuracy and facilitate focus adjustment during exposure, it is necessary that the difference in unevenness on the wafer surface be kept below the depth of focus (flattening). Is done. Also, in the polishing of bare wafers, the demand for flattening has become stricter with the increase in the diameter of the wafers (here, the case of a wafer is described as an example. For example, even when polishing a hard disk substrate, a liquid crystal substrate, or an optical component such as a lens, the surface must be flattened with high precision. In that case, the chemical mechanical polishing method (CMP method) has been spotlighted from the viewpoint that the degree of flattening is high because the surface film is polished, and the film can be embedded in the concave portion.

The CMP method is a chemical / mechanical method using an alkaline slurry using SiO 2, a neutral slurry using CeO 2, an acidic slurry using Al 2 O 3, a slurry using an abrasive, or the like. This is a method of polishing and flattening the wafer surface. As an apparatus for polishing the surface of a wafer by using the CMP method, for example, a polishing apparatus as shown in an enlarged perspective view of a main part in FIG. 5 is known. In the polishing apparatus 1, as schematically shown in FIG. 5, a polishing pad 4 made of, for example, hard urethane is provided on a disk-shaped platen 3 attached to a central shaft 2. In addition, a polishing head 5 that is rotationally driven by a head driving mechanism (not shown) is disposed at a position eccentric from the center axis 2 of the platen 3. Although not shown, the polishing head 5 has a wafer W
And a disc-shaped carrier that holds one surface of the carrier, and an annular retainer ring that is arranged concentrically around the outer periphery of the carrier. The retainer ring is brought into contact with the polishing pad 4 at the time of polishing. The inner peripheral surface of the retainer ring locks the outer periphery of the wafer W held by the carrier, and the lower surface presses the polishing pad 4 to press the wafer W. The deformation of the polishing pad 4 in the vicinity of the outer periphery of the wafer W is suppressed, and the polishing accuracy of the wafer W is ensured.

In the polishing apparatus 1, the wafer W
When the polishing is performed, the slurry S is supplied onto the polishing pad 4.
Flows between the polishing pad 4 and the wafer W held at this time. In this state, the wafer W held by the polishing head 5 rotates on its own axis, and at the same time, the polishing pad 4 rotates around the central axis 2, so that one surface of the wafer W is polished by the polishing pad 4.

[0005]

SUMMARY OF THE INVENTION Such a polishing apparatus 1
Then, the slurry S is supplied to the surface of the polishing pad 4 from the outer peripheral side of the polishing head 5. In this case, most of the supplied slurry S flows outward due to the centrifugal force caused by the rotation of the platen 3, and the slurry reaches the surface of the wafer held on the inner peripheral side of the retainer ring due to the retainer ring acting as a barrier. Since S was difficult to reach, the polishing efficiency of the wafer W was low, and the central portion of the wafer W was difficult to be polished. Then, in order to obtain a sufficient polishing effect, a large amount of the slurry S had to be supplied, and thus a large amount of the expensive slurry S was wasted, and the slurry S could not be used efficiently. In addition, as a polishing head,
Through the gap between the carrier and the retainer ring, the wafer W and the polishing pad 4 are located from the inner peripheral side of the retainer ring.
Some supply a slurry between them. However, even if such a polishing head is used, the slurry flows out to the outer peripheral side due to the centrifugal force generated by the rotation of the polishing head, and the polishing pressure applied to the wafer W is relatively large. , The slurry S may not easily flow around the center of the wafer W depending on the polishing conditions, for example, when the slurry holding groove formed on the surface of the polishing pad 4 becomes shallow.

The present invention has been made in view of such circumstances, and a polishing method capable of satisfactorily polishing a wafer by sufficiently supplying a slurry to the center of a material to be polished regardless of polishing conditions. It is intended to provide a head.

[0007]

In order to solve the above-mentioned problems, a polishing head according to the present invention covers a polishing pad attached to a platen while moving relative to the polishing pad. A polishing head for pressing the polishing material to polish the material to be polished, wherein the polishing head is used for polishing the material to be polished having a through hole formed substantially at the center thereof, and It is characterized by having a slurry supply means for supplying a slurry between the material and the polishing pad. In the polishing head configured as described above, when the polishing target material is polished, the slurry supplied from the slurry supply means is supplied between the polishing target material and the polishing pad through a through hole formed in the polishing target material. Is done. For this reason, even if the retainer ring is provided in the polishing head, the slurry can be directly supplied to the surface to be polished of the material to be polished without being hindered by the retainer ring. Then, the slurry supplied to the central position of the workpiece through the through-hole flows from the central part to the outer peripheral part of the workpiece by centrifugal force caused by the rotation of the polishing head. Supplied. The slurry supplied in this way between the workpiece and the polishing pad is reliably used for polishing the workpiece, so that waste of the slurry is suppressed.

[0008] A support for supporting one surface of a material to be polished is provided on the lower surface of the head body of the polishing head. One end of the support is connected to the slurry supply means, and the other end is connected to the slurry supply means. A flow path that communicates with the approximate center of the lower surface may be provided. In this case, it is possible to supply the slurry to the surface to be polished satisfactorily through the through holes formed in the material to be polished from the flow path provided in the support while reliably supporting the wafer by the support. it can.

[0009] Here, the slurry is liable to be clogged in the gap between the polishing heads due to drying or deterioration thereof gradually, and if such slurry falls on the polishing pad, it causes a scratch on the surface of the material to be polished. . In the polishing head according to the present invention, a cleaning liquid supply means for supplying a cleaning liquid to the flow path of the support is further connected to the flow path of the support. By supplying the cleaning liquid to the flow path, the slurry remaining in the flow path can be washed away by the cleaning liquid. As the cleaning liquid, for example, pure water, a solvent constituting a slurry, or the like may be used.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A polishing head according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view showing a configuration of a polishing head according to the present embodiment, FIG. 2 is a front end view of the polishing head according to the present embodiment, and FIG. 3 schematically shows a main part of the polishing head according to the present embodiment. FIG. The polishing head according to the present embodiment is used instead of the polishing head 5 in, for example, the conventional polishing apparatus shown in FIG. As shown in FIG. 1, a polishing head 11 according to the present embodiment includes a head body 12 including a top plate 13 and a peripheral wall 14 formed in a cylindrical shape, and a diaphragm 15 stretched inside the head body 12. The disc-shaped carrier 1 is fixed to the lower surface of the diaphragm 15 and holds one surface of the wafer W (material to be polished) by the lower surface.
6 (support), and provided concentrically between the inner wall of the peripheral wall portion 14 and the outer peripheral surface 16a of the carrier 16, and held on the carrier 16 by the inner peripheral surface 17a while being in contact with the polishing pad 4 during polishing. An annular retainer ring 17 for locking the outer periphery of the wafer W is provided.

The head main body 12 comprises a disk-shaped top plate 13 and a cylindrical peripheral wall 14 fixed below the outer periphery of the top plate 13. The lower end of the head main body 12 is open and hollow. It has become. The top plate 13 is coaxially fixed to a shaft 19 connected to the main body of the polishing apparatus.
9 has a first flow hole 2 communicating with the pressure adjusting mechanism 30.
5 a and a second flow hole 25 b communicating with the slurry / washing liquid supply mechanism 31 are formed in the vertical direction. Also,
The top plate 13 is provided with a joint 26 for connecting to the slurry / washing liquid supply mechanism 31. From this joint part 26, a head main body conduit 27 communicating with the lower surface side of the top plate part 13 is formed. In addition, the peripheral wall 1
At the lower end of 4, a step 14a is formed over the entire circumference.

A diaphragm 15 made of an elastic material such as fiber reinforced rubber is formed in an annular shape, and its outer peripheral edge is formed by a step 14 a formed on the inner wall of the peripheral wall 14 and a step 1.
It is fixed to the head main body 12 by being sandwiched between the diaphragm fixing ring 21 attached to the head 4a. A fluid chamber 24 is formed above the diaphragm 15, and the fluid chamber 24 is connected to the pressure adjusting mechanism 30 by a first flow hole 25 a formed in the shaft 19. Then, a fluid such as air is supplied into the fluid chamber 24 from the pressure adjusting mechanism 30 through the first circulation hole 25a, so that the pressure inside the fluid chamber 24 is adjusted.

The carrier 16 made of a high-rigidity material such as ceramic is formed in a substantially disc-like shape with a constant thickness, and the diaphragm 15 is sandwiched between a carrier fixing ring 22 provided on the upper surface of the diaphragm 15. It is attached to the diaphragm 15 by being fixed in a state of being bent. As shown in FIGS. 1 to 3, a first flow path 32 is formed in the carrier 16 as a flow path for supplying a slurry or a cleaning liquid to substantially the center of the lower surface 16 c of the carrier 16. The first flow path 32 extends from substantially the center of the upper surface 16 b of the carrier 16 to the carrier 16.
Along the axis of the lower surface 16c.

In the vicinity of the lower end of the first flow path 32, a second flow path 33 is provided along the lower surface 16c of the carrier 16 in a substantially radially outward direction. In the present embodiment, as shown in FIG. 2, a total of four second flow paths 33 are provided.
Are formed at substantially equal angles in the circumferential direction of the carrier 16. As shown in FIG. 1, in the first flow path 32, the opening end on the upper surface 16 b side is connected to the head main body 12 via a first flexible pipe 34 having at least a part of flexibility.
Is connected to a second flow hole 25b formed in the shaft 19. Here, the carrier 16 is moved by the deformation of the first flexible pipe 34.
Is allowed in the axial direction of the head due to the deformation of the head.

Then, as described above, the second flow hole 25
b is connected to a slurry / cleaning liquid supply mechanism 31 for selectively supplying either one of the slurry and the cleaning liquid.
The slurry / cleaning liquid supply mechanism 31 selectively supplies either one of the slurry and the cleaning liquid via the b / first flexible pipe 34. The diameter of the first and second flow paths 32 and 33 is 2 mm.
If it is smaller than 10 mm, the slurry is likely to be clogged.
If it is larger than this, the strength of the carrier 16 is reduced.

Further, on the outer peripheral surface 16a of the carrier 16,
A first groove 35 which is connected to the second flow path 33 and guides the slurry or the cleaning liquid supplied from the second flow path 33 is formed over the entire circumference. The lower inner surface 35 a of the first groove 35 has a shape that is recessed downward as shown in FIG. 3, whereby the slurry supplied from the second flow path 33 to the first groove 35 is formed. Alternatively, the cleaning liquid is temporarily held and flows along the first groove 35. Here, FIG. 3 shows a state of holding the slurry S by the first groove 35 as an example.

The retainer ring 17 is formed in a substantially annular shape as shown in FIG. 1 and has a slight gap between the retainer ring 17 and the inner wall of the peripheral wall portion 14 and the outer peripheral surface 16 a of the carrier 16. And are arranged concentrically. here,
A gap formed between the carrier 16 and the retainer ring 17 is indicated by a symbol K (see FIGS. 2 and 3). The retainer ring 17 is attached to the diaphragm 15 by being fixed to a retainer ring fixing ring 23 provided on the upper surface of the diaphragm 15 with the diaphragm 15 interposed therebetween. Here, an insertion hole H for inserting a second flexible pipe 37 (described later) is formed in the retainer ring fixing ring 23 and the diaphragm 15 at a position facing an opening end of a third flow path 36 described later.
Are formed.

The retainer ring 17 has a plurality of flow paths for supplying slurry or cleaning liquid to a gap K formed between the inner peripheral surface 17a and the outer peripheral surface of the carrier 16 at a plurality of positions in the circumferential direction. Three flow paths 36 are formed.
The third flow path 36 communicates from the upper surface 17b of the retainer ring 17 to the inner peripheral surface 17a. In the present embodiment, as shown in FIG. 2, a total of four third flow paths 36 are formed at substantially equal angles in the circumferential direction of the retainer ring 17. Then, the retainer ring fixing ring 23 and the diaphragm 1
The second flexible pipe 37, which is partially flexible, is inserted through the insertion hole H of No. 5, and the opening end of the third flow path 36 on the upper surface 17b side is connected to the second flexible pipe 37. The head body 12 is connected to a head body conduit 27 formed on the top plate portion 13 of the head body 12 via the same. Here, the retainer ring 17 is allowed to be displaced in the head axis direction due to the deformation of the diaphragm 15 due to the deformation of the second flexible pipe 37.

The second flexible pipe 37 is
The other end is connected to the slurry / washing liquid supply mechanism 31 via a head main body conduit 27 formed on the top plate portion 13 of the head main body 12, whereby the third flow path 36 is connected to the head main body conduit 27. In addition, either the slurry or the cleaning liquid is selectively supplied from the slurry / cleaning liquid supply mechanism 31 via the second flexible pipe 37. When the diameter of the third flow path 36 is smaller than 2 mm, the slurry is likely to be clogged, and when the diameter is larger than 10 mm, the strength of the retainer ring is reduced.

The inner peripheral surface 17a of the retainer ring 17
The second groove 38 is connected to the third flow path 36 and guides the slurry or the cleaning liquid supplied from the third flow path 36.
Are formed over the entire circumference. As shown in FIG.
The lower inner surface 38a of the second groove 38 has a shape that is recessed downward, so that the third flow path 36
The slurry or the cleaning liquid supplied to the second groove 38 is temporarily held and flows along the second groove 38.

As shown in FIG. 1, the slurry / cleaning liquid supply mechanism 31 has a slurry supply source 41 and a cleaning liquid supply source 42, which are respectively provided with second flow holes 25b,
Slurry / washing liquid supply pipe 4 for joint 26
3 are connected. The slurry supplied by the slurry supply source 41 is, for example, an alkaline slurry using SiO2, a neutral slurry using CeO2, or an Al2 slurry.
An acidic slurry using O3, a slurry using an abrasive, or the like is suitable for the polishing conditions of the wafer W. The slurry / cleaning liquid supply pipe 43 serves as a cleaning liquid.
For example, it supplies pure water or a solvent that constitutes the slurry. In the present embodiment, the slurry / cleaning liquid supply pipe 43 is connected to the slurry supply source 41 via a first valve 44, and to the cleaning liquid supply source 42 via a second valve 45. Connected so that one of the first and second valves 44 and 45 is opened and the other is closed so that one of the slurry and the cleaning liquid is selectively supplied. Has become. Here, the mechanism for switching the supply of the slurry or the cleaning liquid to the slurry / cleaning liquid supply pipe 43 is not limited to the mechanism using the first and second valves 44 and 45 as described above. Any of the mechanisms commonly used for can be used.

A polishing apparatus using such a polishing head 11 is for polishing a wafer W having a through hole P formed substantially at the center. This wafer W is provided with an orientation flat and a notch in the same manner as a general wafer W, and is used as a reference for positioning in the circumferential direction at the time of pattern formation. Or the through hole P may be formed in a non-circular shape, for example, an elliptical shape, and the direction of the through hole P may be used as a reference for positioning. In this case, the direction of the wafer W is detected by optically or mechanically detecting the position of the mark with respect to the center of the wafer W or the direction of the through hole P.

Then, the wafer W is
When the polishing is performed, first, the wafer W is attached to a wafer attachment sheet (not shown) provided on the lower surface 16c of the carrier 16, for example. Here, in the wafer adhering sheet, a through hole for passing a slurry or a cleaning liquid is formed at a position facing the first flow path 32 of the carrier 16. The carrier 16 communicates with the first flow path 32 of the
Is held. And the wafer W is the retainer ring 1
7, the surface of which is locked by the platen 3
It is brought into contact with the polishing pad 4 attached to the upper surface. At this time, the lower surface of the retainer ring 17 is also in contact with the polishing pad 4. Here, in the initial state, both the first and second valves 44 and 45 of the slurry / cleaning liquid supply mechanism 31 are closed.

Next, the first flow hole 25a is inserted through the fluid chamber 24.
A fluid such as air flows into the fluid chamber 24.
Adjusting the internal pressure of the carrier 16 and the retainer ring 1
The pressing pressure on the polishing pad 4 is adjusted. Carrier 1
The retainer ring 6 and the retainer ring 17 each have a floating structure supported by the diaphragm 15 and capable of being displaced in the vertical direction, and the pressure applied to the polishing pad 4 can be adjusted by the pressure inside the fluid chamber 24. . Then, while adjusting the pressing pressure of the carrier 16 and the retainer ring 17 against the polishing pad 4, the platen 3 is rotated, and the polishing head 11 is rotated.

At the same time, the first valve 44 of the slurry / washing liquid supply mechanism 31 is opened to supply the slurry from the slurry supply source 41 into the slurry / washing liquid supply pipe 43. Thereafter, during polishing of the wafer W, the first valve 4
4 remains open. Slurry / washing liquid supply pipe 43
Is supplied to the shaft 1 of the head body 12.
9 is supplied to the inside of a second main body channel 27 through a joint 26 provided in the top plate 13 of the head main body 12. Then, the slurry supplied into the second flow hole 25b is supplied into the first flow path 32 of the carrier 16 through the first flexible pipe. The slurry guided to the lower surface 16c of the carrier 16 by the first flow path 32 is supplied directly between the wafer W and the polishing pad 4 through the through hole of the wafer attachment sheet and the through hole P of the wafer W. . The slurry is sent from the center of the wafer W to the outer peripheral side under the centrifugal force generated by the rotation of the polishing head 11 and acts on the entire surface of the wafer W for polishing.

Here, part of the slurry supplied into the first flow path 32 is also sent into the second flow path 33. Then, the slurry guided to the outer peripheral surface 16a of the carrier 16 by the second flow path 33 is guided to the entire periphery of the outer peripheral surface 16a by the first groove 35 formed in the outer peripheral surface 16a, and the entire surface of the outer peripheral surface 16a is Since the slurry flows down from the periphery, the slurry is supplied to the gap K formed between the outer peripheral surface 16a and the inner peripheral surface 17a of the retainer ring 17, that is, the entire periphery of the gap located at the outer periphery of the wafer W.

Further, by supplying the slurry into the first and second flow paths 32 and 33 as described above, the slurry flowing in the first and second flow paths 32 and 33 allows the carrier 16
Is cooled. In the present embodiment, the second flow path 33
Is formed close to the lower surface 16c of the carrier 16 and is formed substantially radially from the center of the carrier 16 toward the outer peripheral side.
Cooling by the slurry is performed over the entire vicinity of c.
Here, in consideration of effective cooling of the carrier 16,
The second flow path 33 is preferably provided as much as possible within a range where the strength of the carrier 16 is not reduced, and is preferably provided close to the lower surface 16c side. Further, since the slurry supplied into the second flow path 33 is sent out toward the outer peripheral surface 16a by the centrifugal force generated by the rotation of the polishing head 11, the slurry is smoothly supplied to the outer peripheral surface 16a. .

On the other hand, the slurry supplied into the head main body conduit 27 is supplied through the second flexible pipe 37 into the third flow path 36 of the retainer ring 17. The slurry guided to the inner peripheral surface 17a by the third flow path 36 is guided to the entire periphery of the inner peripheral surface 17a by the second groove 38 formed in the inner peripheral surface 17a, and the entire periphery of the inner peripheral surface 17a. , The slurry is supplied to the entire periphery in the gap K formed between the inner peripheral surface 17a and the outer peripheral surface 16a of the carrier 16. By supplying the slurry into the gap K in this manner, the slurry is directly supplied between the wafer W and the polishing pad 4 without being hindered by the rotation of the platen 3 and the retainer ring 17.

At an appropriate time such as when the polishing operation is completed, the supply of the slurry from the slurry / washing liquid supply mechanism 31 to the first, second, and third flow paths 32, 33, and 36 is stopped. Instead, the first, second and third channels 32, 33,
The cleaning liquid is supplied into the first, second, and third flow paths 32, 33, and 36, and the entire circumference of the gap K in the circumferential direction. The slurry remaining in the second and third flow paths 32, 33, and 36 and the gap K can be washed away. In the present embodiment,
By closing the first valve 44, the supply of the slurry from the slurry supply source 41 to the slurry / cleaning liquid supply pipe 43 is stopped, and by opening the second valve 45, the slurry / cleaning liquid supply from the cleaning liquid supply source 42 is stopped. The cleaning liquid is supplied to the pipe 43.

According to the polishing head 11 configured as described above, the slurry is brought into contact with the wafer W through the first flow path 32 formed in the carrier 16, the through-hole of the wafer-attached sheet, and the through-hole P of the wafer W. The slurry is directly supplied between the wafer W and the polishing pad 4 without being hindered by the rotation of the platen 3 or the retainer ring 17 because the slurry is directly supplied to the polishing pad 4. The slurry is sent from the center of the wafer W to the outer periphery thereof under the centrifugal force generated by the rotation of the polishing head 11 and acts on the entire surface of the wafer W. As a result, a sufficient amount of slurry can be supplied between the wafer W and the polishing pad 4. In addition, since a sufficient amount of slurry can be supplied to the center side of the wafer W which has conventionally been difficult to supply the slurry, the wafer W can be favorably polished regardless of the polishing conditions.
Since the slurry supplied between the wafer W and the polishing pad 4 in this manner is reliably used for polishing the wafer W, it is used for polishing as compared with the case where a conventional polishing head is used. The amount of the slurry can be dramatically reduced, and the processing cost of the wafer W can be reduced.

Further, in the present embodiment, the slurry is
The wafer W is also supplied between the wafer W and the polishing pad 4 from within the gap K formed between the outer peripheral surface 16a of the carrier 16 and the inner surface 17a of the retainer ring 17, so that the wafer W
The slurry can be supplied also from the outer peripheral side of, and the supply amount of the slurry can be secured. The slurry is supplied to the first groove 35 formed on the outer peripheral surface 16 a of the carrier 16 and the second groove 3 formed on the inner peripheral surface 17 a of the retainer ring 17.
8, the slurry is supplied to the entire circumference within the gap K, so that the slurry is substantially uniformly supplied between the wafer W and the polishing pad 4 from the entire circumference of the wafer W, The polishing amount can be made substantially uniform over the entire surface.
Further, since the slurry supplied between the wafer W and the polishing pad 4 is surrounded by the retainer ring 17, the slurry flows to the outer periphery of the retainer ring 17 even when receiving the centrifugal force due to the rotation of the polishing head 11 and the platen 3. Hard to do. Therefore, polishing can be efficiently performed with a minimum amount of slurry used, and the amount of expensive slurry used can be reduced. The slurry is evenly supplied between the wafer W and the polishing pad 4 by the rotation of the polishing head 11 itself, so that the slurry can efficiently contribute to polishing.

The slurry is supplied to the first and second flow paths 32,
33, the first and second flow paths 32, 3
Since the carrier 16 is cooled by the slurry flowing in the inside 3, the thermal deformation of the carrier 16 can be reduced, and the polishing accuracy of the wafer W can be improved. Since the second flow path 33 is formed substantially radially from the center of the carrier 16 to the outer peripheral side, cooling with the slurry can be performed over the entire vicinity of the lower surface 16 c of the carrier 16 which receives the processing heat. Thermal deformation can be suppressed more effectively. Further, at the time of polishing the wafer W, the slurry can be smoothly supplied to the outer peripheral surface 16a of the carrier 16 by the centrifugal force generated by the rotation of the polishing head 11.

At an appropriate time such as when the polishing operation is completed, the supply of the slurry from the slurry / washing liquid supply mechanism 31 to the first, second, and third flow paths 32, 33, and 36 is stopped. Instead, the first, second and third channels 32, 33,
By supplying the cleaning liquid into the inside 36, the slurry remaining in the first, second and third flow paths 32, 33, 36 and the gap K is washed away by the cleaning liquid before the slurry is dried or deteriorated. be able to.

In the above embodiment, the head body 1
2, the joint 26 provided on the top plate 13
And a third flow path 36 of the retainer ring 17, a head main body conduit 27 communicating with the fluid chamber 24 is formed in the top plate 13, and the head main body conduit 27 is connected to the third flow path 36. The example shown in FIG. 3 is connected by a second flexible pipe 37 disposed in the fluid chamber 24. However, without being limited to this, for example, the polishing head 5 shown in FIG.
1, instead of providing the head main body conduit 27 in the head main body 12, the head main body conduit 5 communicating from the joint portion 26 of the top plate portion 13 to the inner peripheral surface of the step portion 14a of the peripheral wall portion 14 is formed.
In the third flow path 36, the end opened on the upper surface 17 b of the retainer ring 17 is connected to the outer peripheral surface 1.
7c, and the opening end may be connected to the opening end of the head body conduit 52 on the side of the step portion 14a by the second flexible pipe 37.

In the above embodiment, the carrier 16
Although the example in which the second flow path 33 and the first groove 35 are provided on the retainer ring 17 and the third flow path 36 and the second groove 38 are provided in the Even if only the first flow path 32 is formed, the wafer W can be polished favorably. In addition, the support is not limited to the carrier 16 as described above, and may be formed of another member such as a film stretched on the lower surface of the head main body 12.

[0036]

According to the polishing head of the present invention, at the time of polishing a material to be polished, the slurry supplied from the slurry supply means passes through the through-hole formed in the material to be polished and the polishing material and the polishing pad are polished. The slurry can be supplied directly to the surface to be polished of the material to be polished. Then, the slurry supplied to the central position of the workpiece through the through-hole flows from the central part to the outer peripheral part of the workpiece by centrifugal force caused by the rotation of the polishing head. Supplied. In this manner, a sufficient amount of slurry can be supplied between the workpiece and the polishing pad, and a sufficient amount of slurry is also supplied to the center of the workpiece, which has conventionally been difficult to supply the slurry. Since it can be supplied, the material to be polished can be favorably polished regardless of the polishing conditions. Further, since the slurry supplied between the polishing material and the polishing pad is reliably used for polishing the polishing material, the amount of slurry used for polishing is smaller than when a conventional polishing head is used. Can be dramatically reduced, and the processing cost of the material to be polished can be reduced.

A support for supporting one surface of the material to be polished is provided on the lower surface of the head body of the polishing head. One end of the support is connected to the slurry supply means, and the other end is connected to the slurry supply means. By providing a flow path leading to the lower surface, while supporting the wafer securely by the support,
The slurry can be satisfactorily supplied to the surface to be polished through the through holes formed in the material to be polished from the flow path.

Then, a cleaning liquid supply means for supplying a cleaning liquid to the flow path of the support and further to the flow path is connected, and the cleaning liquid is supplied from the cleaning liquid supply means into the flow path at an appropriate time such as when the polishing operation is completed. By doing so, the slurry remaining in the flow path can be washed away with the cleaning liquid before the slurry is dried or deteriorated.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a configuration of a polishing head according to an embodiment of the present invention.

FIG. 2 is a front end view of a polishing head according to an embodiment of the present invention.

FIG. 3 is a partially enlarged view schematically showing a main part of a polishing head according to an embodiment of the present invention.

FIG. 4 is a longitudinal sectional view showing another embodiment of the polishing head of the present invention.

FIG. 5 is a perspective view schematically showing a conventional polishing apparatus.

[Explanation of symbols]

Reference Signs List 1 polishing apparatus 3 platen 4 polishing pad 11 polishing head 16 carrier (support) 31 slurry /
Cleaning liquid supply mechanism 32 First flow path P Through hole W Wafer (material to be polished)

Claims (3)

[Claims] 1. A polishing head for polishing a material to be polished by pressing the material to be polished while moving relatively to the polishing pad on the surface of the polishing pad stuck on a platen. A slurry supply unit that is used for polishing a material to be polished having a through hole formed substantially at the center thereof, and supplies a slurry between the material to be polished and the polishing pad through the through hole of the material to be polished; A polishing head, comprising: 2. A head body is provided with a support for supporting one surface of the material to be polished on the lower surface, the support having one end connected to the slurry supply means and the other end connected to the slurry supply means. The polishing head according to claim 1, wherein a flow path communicating with substantially the center of the lower surface is provided. 3. The polishing head according to claim 2, wherein a cleaning liquid supply unit for supplying a cleaning liquid to the flow path is connected to the flow path of the support.