JP2000000755A - Polishing pad and polishing method - Google Patents

Abstract

(57) [Problem] To provide a polishing pad in which a lattice or concentric groove is provided on a polishing surface, slurry cannot be held in the groove, and a large amount of expensive slurry is wasted. SOLUTION: In a polishing pad 11 having a substantially circular polishing surface 12 for polishing an object to be polished (not shown), grooves 13 are provided discontinuously from the center to the peripheral edge of the polishing surface 12. As a result, the slurry (not shown) guided into the groove 13 overflows from the groove 13 while being discharged to the outside of the polishing surface 12 by centrifugal force, and is again supplied to the polishing surface 12 outside the groove 13. Become like

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing pad and a polishing method using the polishing pad. More specifically, the present invention relates to a polishing apparatus for polishing an interlayer insulating film in a semiconductor device manufacturing process by chemical mechanical polishing. The present invention relates to a polishing method by chemical mechanical polishing using a pad and a polishing pad.

[0002]

2. Description of the Related Art With the recent miniaturization of design rules in semiconductor devices, efforts have been made to increase the resolution of lithography. By increasing the resolution, the depth of focus, so-called DOF (Depth Of Focus), has been reduced. This improvement has to wait for the improvement of the resist performance. However, at present, the demand for miniaturization precedes the improvement of the resist performance. Therefore, a method of compensating for the lack of the depth of focus by minimizing the height difference of the device structure as much as possible and reliably resolving the fine pattern without causing a defocus has been studied.

As a method of flattening a difference in height of a device structure, recently, chemical mechanical polishing using mirror finishing of a silicon wafer has been adopted. A polishing apparatus for performing the chemical mechanical polishing is provided with a rotatable polishing plate on which a polishing pad is mounted. At a position facing the polishing pad, a carrier for holding the body to be polished via an adhesive sheet and a dresser for sharpening the polishing pad are rotatably provided. Further, a nozzle for supplying a slurry onto the polishing pad is disposed substantially at the center of the polishing pad.

[0004] A polishing method using the above polishing apparatus will be described below. First, the polishing plate and the dresser are rotated, and the polishing pad mounted on the polishing plate is dressed by the dresser. Thereafter, the polishing plate and the carrier are rotated, and while the slurry is supplied from the nozzle onto the polishing pad, the polishing object held by the carrier is pressed against the polishing pad to polish the polishing object.

[0005] In the above-mentioned chemical mechanical polishing apparatus, micro-scratch occurs in the object to be polished. In addition, variations in the polishing rate and in-plane variations in the polishing amount are large. The generation of micro scratches is caused by shavings of the polishing pad generated during dressing of the polishing pad, diamond abrasive grains of the dresser, polishing debris of the object to be polished, polished slurry, etc. (hereinafter, these are referred to as impurities). I have.
Therefore, in the chemical mechanical polishing apparatus, during the polishing operation, the slurry is sufficiently supplied to the center of the polishing pad without interruption, and the slurry discharges impurities to the outside of the polishing pad.

[0006] On the other hand, a large variation in polishing rate and in-plane variation in polishing amount can be achieved by forming a shallow dressing layer on the polishing pad surface by making the dresser innumerably scratch the surface of the polishing pad. Has improved. As a result, the slurry is held by the dressing layer, and the slurry can be sufficiently supplied to the surface to be polished of the object to be polished pressed against the polishing pad. In addition, polishing proceeds, so that dressing of the polishing pad surface with a dresser, so-called dressing, is performed so that the depth and density of the dressing layer are sufficient. Furthermore, by ensuring that the polishing slurry is sufficiently distributed on the surface to be polished in conjunction with a sufficient supply of the slurry which is also performed as a measure for preventing the above-mentioned micro-scratch, variations in the polishing rate and in-plane variations in the polishing amount are reduced. We are taking measures to reduce it.

[0007]

However, when the dressing layer is formed by dressing as described above, and the slurry is supplied to perform polishing of the object to be polished, the slurry is subjected to the centrifugal force due to the rotation of the polishing pad and the object to be polished. The polishing body is extruded by pressing the polishing body against the polishing pad, and most is discharged out of the polishing pad without directly contributing to polishing. Thus, a large amount of expensive slurry is wasted.

Conventionally, as shown in FIG. 7, a lattice-shaped groove 141 is formed on a polishing surface 112S of a substantially circular polishing pad 112, and a slurry (not shown) is stored in the groove 141 to form a slurry. It has been practiced to increase the chances of contact between the substrate and the object to be polished (not shown). However, even with such a structure, the slurry is discharged out of the polishing pad 112 through the groove 141, and a large amount of expensive slurry is wasted similarly to the above.

Further, as shown in FIG. 8, there is a polishing pad 112 having a substantially circular polishing pad 112 in which a concentric groove 142 is formed on a polishing surface 112S. However, even with such a structure, the grooves 14 may be formed by centrifugal force generated by the rotation of the polishing pad 112.
The slurry (not shown) accumulated in the polishing pad 11 remains on the outer peripheral side of the polishing pad 112 in the groove 142.
Therefore, the chance of contact between the slurry and the object to be polished (not shown) is not sufficient. Also, as described with reference to FIG. 7, a large amount of expensive slurry wasted.

As described above, the fact that the slurry is discharged out of the polishing pad without being effectively used increases the cost of chemical mechanical polishing, and the slurry is not sufficiently supplied to the surface to be polished. Polishing quality is to be reduced.

[0011]

SUMMARY OF THE INVENTION The present invention provides a polishing pad and a polishing method for solving the above problems.
The invention according to claim 1 is a polishing pad having a substantially circular polishing surface for polishing an object to be polished, wherein the polishing surface is provided with a discontinuous groove from the center to the periphery. It is characterized by:

In the polishing pad according to the first aspect, since the groove provided from the center of the substantially circular polishing surface to the peripheral edge is discontinuous, the slurry introduced into this groove during polishing is In the process of being discharged to the outside of the polishing surface by centrifugal force, it overflows from the groove and is supplied again to the polishing surface outside the groove. Therefore, the chance that the slurry comes into contact with the surface to be polished of the body to be polished is efficiently increased.

According to a fourth aspect of the present invention, there is provided a polishing pad having a substantially circular polishing surface for polishing an object to be polished, wherein the polishing surface is provided with a groove extending from the center to the peripheral edge thereof. Is characterized in that a pleat is formed on the bottom surface of the groove so as to divide the groove in the extending direction.

[0014] In the polishing pad according to the fourth aspect, the groove provided from the center of the substantially circular polishing surface to the peripheral edge is divided in the extending direction by the pleated body erected on the bottom surface of the groove. It is in a state. Therefore, during the polishing, the slurry guided into the groove overflows from the groove at the part cut by the pleats and is again supplied onto the polishing surface outside the groove in the process of being discharged to the outside of the polishing surface by centrifugal force. Is done. Therefore, the chance that the slurry and the surface to be polished come into contact with each other is efficiently increased.

Further, according to a seventh aspect of the present invention, in a belt-like polishing pad having a polishing surface for polishing an object to be polished, the entirety of the polishing surface of the polishing pad includes a moving direction of the polishing surface and a direction substantially similar to the moving direction. It is characterized in that a discontinuous groove is provided in the vertical width direction.

In the polishing pad according to the seventh aspect of the present invention, since the polishing surface is provided with the groove, the slurry which is to be discharged backward by the movement of the polishing surface, and the rotation of the object to be polished on the polishing surface. Thereby, the slurry to be discharged in the width direction of the polishing surface is guided into the groove. Since this groove is discontinuous in the direction of movement of the polishing surface and in the width direction substantially perpendicular thereto, the slurry introduced into the groove overflows from the groove in the process of being discharged in the above-mentioned direction, and again flows into the groove. Supplied on the outer polishing surface. Therefore, the chance that the slurry comes into contact with the surface to be polished of the body to be polished is efficiently increased.

According to a tenth aspect of the present invention, in a belt-like polishing pad having a polishing surface for polishing an object to be polished, a groove is provided on the entire polishing surface of the polishing pad.
A pleated body is provided on the bottom surface of the groove so as to divide the inside of the groove in the extending direction thereof.

In the polishing pad according to the tenth aspect,
Since the grooves are formed in the polishing surface, the slurry is to be discharged to the rear by the movement of the polishing surface, and the slurry is to be discharged in the width direction of the polishing surface by the rotation of the object to be polished on the polishing surface. Is guided into the groove. Since the inside of the groove is divided in the extending direction by the ridges standing on the bottom surface, the slurry guided into the groove is divided by the folds in the process of being discharged in the above direction. The part overflows from the groove and is supplied again to the polishing surface outside the groove. Therefore, the chance that the slurry comes into contact with the surface to be polished of the body to be polished is efficiently increased.

An eleventh aspect of the present invention is a polishing method using a polishing pad in which a groove is provided in a polishing surface for polishing an object to be polished, wherein the polishing is performed by pressing the object to be polished against the polishing surface. In this case, the pressure on the polished surface of the object to be polished is temporarily relaxed.

In the above-mentioned polishing method, when the polishing is performed, the pressure applied to the polished surface of the object to be polished is relaxed, so that the slurry introduced into the grooves on the polished surface is easily discharged out of the grooves. For this reason, the slurry is easily supplied between the polished surface of the polished body and the polished surface, and the chance that the slurry comes into contact with the polished surface of the polished body is efficiently increased.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) An example of a polishing pad to which the invention according to claims 1, 2, and 3 is applied is referred to as a first embodiment, and this first embodiment is shown in FIG. The schematic configuration diagram of the polishing pad of FIG. 2 and the schematic configuration diagram of the polishing apparatus of FIG. 2 will be described. FIG. 1A is a plan view of the polishing pad, and FIG. 1B is an enlarged cross-sectional view taken along line AA.

As shown in FIGS. 1 (1) and 1 (2),
The polishing pad 11 is made of a resin having hardness and elasticity such that a global flatness can be obtained, for example, a urethane resin, and has a substantially circular polishing surface 12. This polished surface 12
Has grooves 13 extending in four directions from the center of the polishing surface 12 to the periphery. These grooves 13 are discontinuous from the center of the polishing surface 12 to the peripheral edge, and a plurality of independent grooves 13 extend from the center of the polishing surface 12 to the peripheral edge.
Are arranged. In addition, these grooves 13
Are formed at the same depth, or the polished surface 1
The closer to the periphery of 2, the shallower. Here, it is assumed that the groove 13 located near the peripheral edge of the polishing surface 12 is formed shallower.

The polishing pad 1 is provided inside each groove 13.
Slurry holder 1 made of a sponge-like urethane resin having a foamed size larger than the urethane resin constituting foam 1 or having a larger foaming amount, or both.
4 may be filled. Here, the slurry holding resistance 14 is provided inside each groove 13.

In the polishing pad 11 having the above structure, the groove 13 is provided from the center of the substantially circular polishing surface 12 to the periphery. For this reason, it is supplied onto the polishing surface 12 at the time of polishing, and the centrifugal force due to the rotation of the polishing surface 12 and the object to be polished (not shown) are pressed against the polishing surface 12 to be discharged to the outside of the polishing surface 12. The slurry (not shown) to be performed is guided into the groove 13. Since the groove 13 is discontinuous from the center of the polishing surface 12 to the peripheral edge, the slurry introduced into the groove 13 is further discharged (in the groove 13) by centrifugal force in the process of being discharged to the outside. And is supplied again onto the polishing surface 12 outside the groove 13. Therefore, the chance that the slurry comes into contact with the surface to be polished of the body to be polished is efficiently increased. As a result, the quality of the polished surface is improved,
The amount of slurry can be reduced by effective use of the slurry.

Moreover, since the grooves 13 located closer to the peripheral edge of the polishing surface 12 are formed shallower, the effect of holding the slurry in the grooves 13 is higher as the position is closer to the center of the polishing surface 12. Therefore, the chance that the slurry comes into contact with the surface to be polished of the object to be polished can be efficiently increased toward the center of the polishing surface 12 where the slurry is difficult to be held, and the supply of the slurry on the polishing surface 12 is made uniform. It becomes possible to do.

In each groove 13, a slurry holder 14 is provided.
Is provided, the slurry guided into the groove 13 is easily captured by the slurry holder 14 and held in the groove 13. Therefore, the chance that the slurry comes into contact with the surface to be polished of the object to be polished can be more efficiently increased.

When a sponge-like urethane material having a large foam size and / or a large foam amount is used for the polishing pad 11, the hardness and elasticity are low, so that the polishing pressure of the object to be polished during polishing is low. The polishing pad 11 is crushed. As a result, the slurry is squeezed out from between the object to be polished and the polishing pad 11, and the slurry cannot be sufficiently held. In addition, the low flatness of the polishing pad 11 deteriorates the global flatness of the polished surface. Therefore, the polishing pad 11 needs to have hardness and elasticity required for polishing. Therefore, grooves 13 are formed in the polishing pad 11 having the required hardness and elasticity,
By filling the groove 13 with, for example, a sponge-like urethane foam having a hardness smaller than that of the polishing pad 11 and easily holding slurry, for example, it is possible to perform slurry holding and polishing while maintaining global flatness. Become.

Next, a method of forming the polishing pad 11 will be described below. First, a groove 13 is formed in the polishing pad 11. Alternatively, the polishing pad 11 having the shape provided with the groove 13 may be formed. Next, the urethane material to which the foaming agent is added is poured into the groove 13 of the polishing pad, and then heated to foam the urethane material in the groove 13. And groove 13
The urethane material overflowing from the polishing pad 11 is removed to expose the polishing surface of the polishing pad 11, and the foamed urethane material, that is, the slurry holding body 14 made of a porous urethane material is left by leaving the foamed urethane material only in the groove 13. Is formed in the groove 13. Thus, the polishing pad 11 is formed.

The polishing pad 11 is mounted on, for example, a polishing apparatus (for example, a chemical mechanical polishing apparatus) 81 as shown in FIG. Hereinafter, the polishing apparatus 81 will be described.

As shown in FIG. 2, the polishing apparatus 81 has a polishing plate 82 rotatably provided. The polishing pad 11 described above is mounted on the polishing plate 82. One end of a rotating shaft 83 is connected to the polishing plate 82, and a rotating drive source (not shown) is connected to the other end of the rotating shaft 83.

Above the polishing pad 11, a carrier 84 is rotatably provided. The body to be polished 71 is held on the surface of the carrier 84 on the side of the polishing plate 82 via an adhesive sheet 85. Further, one end of a rotating shaft 86 is connected to the carrier 84, and a rotating drive source (not shown) is connected to the other end of the rotating shaft 86. A part 87 is provided.

On the substantially central portion of the polishing pad 11,
A slurry supply nozzle 89 connected to the slurry supply device 88 is provided.

Further, a dresser 90 is rotatably provided above the polishing pad 11. On the surface of the dresser 90 on the side of the polishing plate 82, a dressing layer 91 in which, for example, diamond abrasive grains are electrodeposited on a metal plate is formed. One end of a rotating shaft 92 is connected to the dresser 90, and a rotating drive source (not shown) is connected to the other end of the rotating shaft 92, and a pressure adjusting unit that adjusts dressing pressure. (Not shown) is provided.

To polish the object 71 using the polishing apparatus 81, first, the polishing pad 11 is dressed by a dresser 90. Thereafter, the polishing plate 82 and the carrier 84 are rotated, and while the slurry 75 is supplied from the slurry supply nozzle 89 onto the polishing pad 11, the carrier 84 is pressed against the polishing pad 11 by the polishing pressure adjusting unit 87 to be polished. The body 71 is pressed against the polishing pad 11 to polish the body 71 to be polished. At this time, since the slurry 75 is guided into the groove 13 of the polishing pad 11 (see FIG. 1), the chance of contact between the slurry 75 and the body 71 to be polished is increased, and the quality of the surface to be polished as described above is improved. And the effect that the amount of slurry can be reduced by effective use of the slurry 75 can be obtained.

At the time of the above-mentioned polishing, a step of temporarily relaxing the pressure (ie, the polishing pressure) for pressing the carrier 84 against the polishing pad 11 by the polishing pressure adjusting section 87 is provided at least once. This is a polishing method according to claim 11. By performing the polishing in this manner, when the polishing pressure is reduced, the grooves 1 of the polishing pad 11 are removed.
The slurry 75 guided into the inside 3 overflows from the groove 13 and is easily discharged onto the polishing pad 11. That is, the object to be polished 7
1 (the surface to be polished) and the polishing pad 11 (the surface to be polished) are easily supplied, and the chance that the slurry comes into contact with the surface to be polished of the object to be polished is efficiently increased.

(Second Embodiment) Next, another example of a polishing pad to which the invention according to claims 1, 2 and 3 is applied will be referred to as a second embodiment. The polishing pad No. 3 will be described with reference to a schematic configuration diagram. Fig. 3 (1)
Shows a plan view of the polishing pad, and FIG. 3 (2) shows an enlarged cross-sectional view taken along line BB. In FIG. 3, the same components as those described with reference to FIG. 1 are denoted by the same reference numerals.

The difference between the polishing pad of the second embodiment and the polishing pad of the first embodiment is that the polishing surface 1
The arrangement of the groove 13 in FIG. 2 and the slurry holder 14 disposed in the groove 13 are the same, and the other configuration is the same. That is, as shown in FIG.
The grooves 13 provided discontinuously from the center of the polishing surface 12 to the periphery are arranged on a plurality of different axes extending from the center of the polishing surface 12 to the periphery. Polished surface 1
It is assumed that the groove 13 located closer to the peripheral edge in 2 is formed shallower.

Further, as shown in FIG.
The slurry holder 14 provided inside 3 is formed by densely growing a fibrous urethane resin on the bottom surface of the groove 13.

In the polishing pad 11 having the above-described configuration, the discontinuous groove 13 is provided from the center of the substantially circular polishing surface 12 to the peripheral edge, so that the slurry (not shown) is covered with the slurry similarly to the first embodiment. The chance of contact with the surface to be polished of the polishing body (not shown) can be efficiently increased. Moreover, by disposing each groove 13 on a plurality of different axes extending from the center of the polishing surface 12 to the peripheral edge, the slurry overflowing from the groove 13 is guided to the outer groove 13 on the polishing surface 12 again. The journey becomes longer. Therefore, the time during which the slurry is supplied to the surface to be polished of the object to be polished can be lengthened.
Therefore, it is possible to further improve the quality of the surface to be polished, and to reduce the amount of slurry by effectively using the slurry.

Further, since the grooves 13 arranged closer to the periphery of the polishing surface 12 are formed so as to be shallower, and the slurry holder 14 is provided in each groove 13, the same as in the first embodiment, The supply of the slurry is made uniform, and the chance that the slurry comes into contact with the surface to be polished of the object to be polished can be more efficiently increased.

The method for forming the polishing pad 11 will be described below. First, a groove 13 is formed in the polishing pad 11. Alternatively, the polishing pad 11 provided with the groove 13 may be formed. After that, the urethane material processed into a fiber shape is bundled, and the end is bonded to the bottom of the groove 13. For the bonding, an adhesive may be used, or bonding may be performed by thermocompression bonding, or bonding may be performed by using an adhesive and thermocompression bonding. Then, the bundle of fibers that are out of the groove 13 is cut in accordance with the height of the polishing surface 12 of the polishing pad 11, so that the slurry holder 14 made of a fibrous urethane material is cut.
Is formed in the groove 13. Thus, the polishing pad 1
Form one.

In the second embodiment, the urethane material processed into a fibrous shape is bundled, and its end is adhered to the bottom of the groove 13 to allow the fibrous urethane material to grow densely in the groove to form a slurry holder 14. The slurry holder 1 is formed by laminating, for example, a urethane material processed into a fibrous shape in the groove 13.
4 may be formed. Also in this case, the slurry holder 14
Of the polishing pad 11 is almost equal to the polishing surface 12 of the polishing pad 11.

In the second embodiment described above, the same slurry holder as in the first embodiment may be provided in the groove 13. Similarly, the slurry holder 14 used in the second embodiment may be provided in a groove in the polishing pad of the first embodiment.

In the first and second embodiments, the groove 1 is linearly moved from the center of the polishing surface 12 to the peripheral edge.
3 has been described. However, this groove 1
3 may be provided discontinuously from the center to the periphery, and is not limited to the above-described arrangement. For example, grooves arranged in a state where a plurality of mesh-shaped grooves are divided on the entire surface of the polishing surface 12 or grooves having a shape in which the groove width is partially different may be arranged.

(Third Embodiment) Next, an example of a polishing pad to which the invention according to claims 4, 5, and 6 is applied will be referred to as a third embodiment, and this third embodiment will be described with reference to FIG. The polishing pad will be described with reference to a schematic configuration diagram. FIG. 4A shows a plan view of the polishing pad, and FIG. 4B shows an enlarged cross-sectional view taken along the line CC. In FIG. 4, the same components as those described with reference to FIG. 1 are denoted by the same reference numerals.

As shown in FIGS. 4 (1) and 4 (2),
The polishing pad 11 is the same as that of the first embodiment, and has a substantially circular polishing surface 12. This polished surface 12
Is provided with a groove 13 ′ extending from the center of the polishing surface 12 to the periphery thereof in a plurality of directions. Here, as an example, the grooves 1 are arranged in four directions from the center of the polishing surface 12.
The case where 3 ′ is provided is shown. This groove 13 '
Are formed at the same depth or are polished
Are formed shallower nearer the periphery. here,
It is assumed that the depth of the groove 13 ′ is formed shallower toward the periphery of the polishing surface 12.

On the bottom surface of the groove 13 ', a fold 15 is erected so as to divide the groove 13' in the extending direction. The fold 15 is made of, for example, a urethane material, and is provided in a dense state on the bottom surface of the groove 13 ′. The fold can be formed in a flat plate shape, a corrugated plate shape, or the like. is there. And the formation direction of the pleat 15 is
It is sufficient that the groove 13 'is divided in the direction in which the groove 13' extends.
A direction parallel to the rotation direction of the polishing surface 12, a direction in which a surface toward the center of the polishing surface 12 is directed forward in the rotation direction of the polishing surface 12,
Alternatively, the surface facing the center of the polishing surface 12 is set in any direction in the direction toward the rear of the polishing surface 12 in the rotation direction.

In the polishing pad 11 having the above structure, a groove 13 'is provided from the center of the substantially circular polishing surface 12 to the peripheral edge. For this reason, it is supplied onto the polishing surface 12 at the time of polishing, and the centrifugal force due to the rotation of the polishing surface 12 and the object to be polished (not shown) are pressed against the polishing surface 12 to be discharged to the outside of the polishing surface 12. The slurry (not shown) to be performed is guided into the groove 13 '. Since the folds 15 were densely formed on the bottom surface of the groove 13 ′ while dividing the extending direction of the groove 13 ′, the slurry led into the groove 13 ′ ) In the process of being discharged to the outside by centrifugal force, the pleats 15 are blocked by the pleats 15 and overflow from the groove 13 ′, and are again supplied onto the polishing surface 12 outside the groove 13 ′. Moreover, the slurry guided into the groove 13 ′
It is held in the groove 13 ′ while being captured between the folds 15. For this reason, the fold 15 also functions as a slurry holder. Accordingly, the chance that the slurry comes into contact with the surface to be polished of the object to be polished is efficiently increased, and the opportunity of supplying the slurry to the surface of the object to be polished during polishing is increased, and the quality of the surface to be polished is improved. It is possible to reduce the amount of slurry by effectively utilizing the slurry.

When the ridge 15 is formed such that the surface facing the center of the polishing surface 12 is directed forward in the rotation direction of the polishing surface 12, the fold 15 is formed.
The slurry held in between overflows from the groove 13 ′ so as to return to the center direction of the polishing surface, and the slurry 12
The retention time of the slurry above can be increased. On the other hand, when the formation direction of the pleated body 15 is set so that the surface facing the center of the polishing surface 12 is directed backward in the rotational direction of the polished surface 12, the pleated body 15 is formed.
The slurry held therebetween overflows from the groove 13 ′ toward the peripheral edge of the polishing surface 12, so that the rectification of the slurry on the polishing surface 12 can be obtained.

The method of forming the polishing pad 11 will be described below. First, a groove 13 ′ is formed in the polishing pad 11.
Alternatively, the polishing pad 11 provided with the groove 13 'may be formed. Next, the urethane material is applied to the grooves 13 ′ of the polishing pad 11.
After that, a mold for forming a pleated body is inserted into the urethane material, and the urethane material is cured by heating. After that, the above-mentioned mold is extracted to form the pleat 15 made of urethane material in a state of standing upright on the bottom surface of the groove 13 ′. Then, the groove 13 ′ is formed so that the upper end of the fold 15 is aligned with the height of the polishing surface 12 of the polishing pad 11.
The protruding pleats 15 are removed, thereby forming the polishing pad 11.

In the third embodiment, the grooves 13 'linearly extending from the center of the polishing surface 12 to the peripheral edge are shown. However, the grooves 13 ′ arranged on the polishing surface 12
It is not limited to the grooves in the arrangement state as described above,
What is necessary is just to provide from the center to the periphery. For example,
It may be a groove provided in the shape of a mesh on the entire surface of the polishing surface 12, or a groove having a shape partially different in width.

The polishing using the polishing pads of the second embodiment and the third embodiment is the same as that of the first embodiment shown in FIG.
The polishing can be performed in the same manner as described in the first embodiment using the polishing apparatus described with reference to FIG.

(Fourth Embodiment) Next, an example of a polishing pad to which the invention according to claims 7, 8 and 9 is applied will be referred to as a fourth embodiment, and this fourth embodiment will be described with reference to FIG. The polishing pad will be described with reference to a schematic configuration diagram. FIG. 5A shows a configuration diagram of the polishing pad, and FIG. 5B shows an enlarged cross-sectional view taken along line DD.

As shown in FIGS. 5 (1) and 5 (2),
The polishing pad 21 has a belt shape made of the same material as that of the first embodiment, and has an outer peripheral surface serving as a polishing surface 22. The polishing surface 22 is provided with a discontinuous groove 23 extending in a belt-like longitudinal direction. That is, the grooves are provided on the polishing surface 22 discontinuously in the moving direction of the polishing surface 22 and the width direction substantially perpendicular thereto. Each of these grooves 23 is formed shallower toward the rear in the direction of movement of the polishing surface 22 as indicated by a white arrow in the drawing. However, the groove 23 may be formed at the same depth. In addition, each of these grooves 23
Is provided with a slurry holder 24 similar to that described in the first embodiment.

In the polishing pad 21 having the above structure, the polishing surface 2
The slurry (not shown) which is to be discharged to the rear by the movement of the polishing pad 2 and the slurry which is to be discharged in the width direction of the polishing surface 22 by the rotation of the object to be polished on the polishing surface 21 are introduced into the grooves 23. I will Since the grooves 23 are discontinuous in the direction of movement of the polishing surface 22 and the width direction substantially perpendicular thereto, the process of discharging the slurry guided into the grooves 23 (in the grooves 23) in the above-described direction. , Overflows from the groove 23 and is supplied to the polishing surface 22 outside the groove 23 again. For this reason,
The opportunity for the slurry to come into contact with the surface to be polished of the object to be polished (not shown) is efficiently increased. As a result, the quality of the surface to be polished can be improved, and the amount of slurry can be reduced by effectively using the slurry.

Moreover, since the groove 23 is formed shallower toward the rear in the direction of movement of the polishing surface 22, the effect of holding the slurry in the groove 23 becomes higher as the groove 23 moves forward in the direction of movement of the polishing surface 22. . Therefore, the more the slurry is hardly held, the more the chance of the slurry coming into contact with the polished surface of the object to be polished can be efficiently increased in the direction of movement of the polished surface 22, and the supply of the slurry on the polished surface 22 Can be made uniform.

In each groove 23, a slurry holder 24 is provided.
Is provided, the slurry guided into the groove 23 is easily captured by the slurry holder 24 and held in the groove 23. Therefore, the chance that the slurry comes into contact with the surface to be polished of the object to be polished is more efficiently increased.

The method for forming the polishing pad 21 is the same as that described in the first embodiment.

The slurry holder 2 provided in the groove 23
4 may be the same slurry holder as used in the second embodiment. The formation of the polishing pad 21 in this case is performed in the second step.
This is performed in the same manner as described in the embodiment.

In the fourth embodiment, the case where the groove 23 extends linearly in the longitudinal direction of the polishing surface 22 has been described. However, the grooves 23 are not limited to the grooves arranged as described above, and may be provided discontinuously in the moving direction of the polishing surface 22 and the width direction substantially perpendicular thereto. . For this reason, for example, a plurality of grooves provided in a mesh pattern on the entire surface of the polishing surface 22 are divided, or the grooves are discontinuously extended in the width direction of the polishing surface 22 or in an oblique direction with respect to the groove. It may have a shape with a different width.

(Fifth Embodiment) Next, an example of a polishing pad to which the invention according to claim 10 is applied will be referred to as a fifth embodiment, and the fifth embodiment will be described with reference to the schematic configuration diagram of the polishing pad shown in FIG. I do. FIG. 6A shows a configuration diagram of the polishing pad, and FIG. 6B shows an enlarged cross-sectional view taken along line EE.

As shown in FIGS. 6 (1) and 6 (2),
The polishing pad 21 is a belt-like material made of the same material as that of the fourth embodiment, and has an outer peripheral surface serving as a polishing surface 22. The polishing surface 22 is provided with a groove 23 'continuously extending in a belt-like longitudinal direction.

On the bottom surface of the groove 23 ′, a pleated body 25 is erected so as to divide the extending direction of the groove 23 ′. The folds 25 are made of, for example, a urethane material, and are provided in a dense state on the bottom surface of the groove 23 ′. The folds can be formed in a flat plate shape, a corrugated plate shape, or the like. is there. The direction in which the folds 25 are formed is substantially parallel to the direction of movement of the polishing surface.

In the polishing pad 21 having the above structure, the polishing surface 2
Since the groove 23 ′ is provided in the polishing surface 2, the slurry (not shown) which is to be discharged behind the polishing surface 22 by the movement of the polishing surface 22 and the polishing by the rotation of the object to be polished (not shown) on the polishing surface 22 The slurry to be discharged in the width direction of the surface 22 is guided into the groove 23 '. Inside this groove 23 '
Since the extending direction is divided by the pleats 25 erected on the bottom surface, the slurry guided into the groove 23 ′ (in the groove 23 ′) is discharged in the above direction (in the groove 23 ′). ′, And is supplied again onto the polishing surface 22 outside the groove 23 ′. Moreover, the slurry guided into the groove 23 ′ is captured between the folds 25 and held in the groove 23 ′. For this reason, the pleated body 25 also functions as a slurry holder. Therefore, the chance that the slurry comes into contact with the surface to be polished of the body to be polished is efficiently increased. As a result, the quality of the surface to be polished can be improved, and the amount of slurry can be reduced by effectively using the slurry.

The method for forming the polishing pad 21 is the same as that described in the third embodiment.

In the fifth embodiment, the case where the groove 23 ′ extends linearly in the longitudinal direction of the polishing surface 22 has been described. However, the groove 23 ′ is not limited to the groove in the above-described arrangement state, but may be provided over the entire surface of the polishing surface 22. For this reason, for example, grooves provided in a mesh pattern on the entire surface of the polishing surface 22 or the polishing surface 22
May extend in the width direction or a slant direction to this direction, or may have a shape in which the width is partially different.

Further, in order to perform polishing using the polishing pads of the fourth and fifth embodiments, the polishing plate in the polishing apparatus described in the first embodiment with reference to FIG. And a polishing apparatus having a belt-shaped polishing pad 21 mounted on the outer periphery thereof is used. Then, polishing is performed by using this polishing apparatus in the same manner as described in the first embodiment.

Further, in the first to fifth embodiments, urethane is used as the resin for forming the slurry holders 14, 24 and the folds 15, 25, but silicon rubber, hard rubber, fluorine resin It is also possible to use nylon, vinyl chloride or other resins. Alternatively, it may be formed of a plurality of types of resins. Further, the polishing pad described in each of the above embodiments is not limited to urethane resin, and other resins or metals can be used. In each of the above embodiments, the slurry holders 14, 24, the pleated members 15, 25, and the polishing pad 1
Although the heights of the polished surfaces 12 and 22 are substantially equal to each other, the heights need not necessarily be equal. The height of the slurry holders 14, 24 and the folds 15, 25 is
The polishing pads 11 and 21, the slurry holders 14 and 24, the folds 15 and 25, and the hardness, elasticity, etc. of the object to be polished,
It is set appropriately.

The grooves 13, 13 ', 23, 23'
The cross-sectional shape of is not limited to the rectangular shape as shown,
It may be V-shaped or U-shaped.

As described in the first to fifth embodiments, in the polishing using the polishing pad of the present invention, for example, the surface of the object to be polished having a step is pressed against the polishing surface of the polishing pad by chemical mechanical polishing. Polishing is effective in flattening the surface to be polished of the object to be polished.

Further, a groove may be formed in the polishing pad, or a slurry holder or a pleated body may be provided in the groove.
It is possible to use a conventional polishing apparatus as it is. Therefore, it is possible to realize the polishing pad with little change in life and usability without imposing a facility load on the current production system. That is, a so-called user-friendly measure can be taken.

[0072]

As described above, according to the polishing pad of the present invention, the grooves are provided discontinuously on the polishing surface side, or the grooves are divided by pleated members to make the grooves discontinuous. The slurry that is used for or is discharged to the outside of the polishing pad without contributing to polishing is guided into the groove, and the slurry that is discharged to the outside of the polishing pad in the groove overflows from the groove to be on the polishing surface outside the groove. Can be supplied again. This increases the chances of the slurry coming into contact with the surface to be polished of the object to be polished, so that expensive slurry can be effectively used. At the same time, the polishing shape, polishing rate, and polishing uniformity on the surface to be polished can be improved, the polishing quality can be improved, and the process cost can be reduced by reducing the amount of slurry used.

Further, according to the polishing method of the present invention, by temporarily relaxing the polishing pressure of the object to be polished on the polishing surface on which the groove is formed, the slurry introduced into the groove on the polishing surface is removed. Therefore, it is possible to facilitate supply between the polished surface and the polished surface of the polished body. This increases the chances of the slurry coming into contact with the surface to be polished of the object to be polished, so that expensive slurry can be effectively used. At the same time, the polishing shape, polishing rate, and polishing uniformity on the surface to be polished can be improved, the polishing quality can be improved, and the process cost can be reduced by reducing the amount of slurry used.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a polishing pad according to a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a polishing apparatus.

FIG. 3 is a diagram illustrating a polishing pad according to a second embodiment of the present invention.

FIG. 4 is a diagram illustrating a polishing pad according to a third embodiment of the present invention.

FIG. 5 is a diagram illustrating a polishing pad according to a fourth embodiment of the present invention.

FIG. 6 is a diagram illustrating a polishing pad according to a fifth embodiment of the present invention.

FIG. 7 is an explanatory view of a groove shape related to a conventional polishing pad.

FIG. 8 is an explanatory view of a groove shape related to a conventional polishing pad.

[Explanation of symbols]

11, 21 ... polishing pad, 12, 22 ... polishing surface, 13,
13 ', 23, 23' ... groove, 14, 24 ... slurry holder, 15, 25 ... pleated body

Claims (11)

[Claims] 1. A polishing pad having a substantially circular polishing surface for polishing an object to be polished, wherein the polishing surface is provided with a discontinuous groove from the center to the periphery. . 2. The polishing pad according to claim 1, wherein the depth of the groove is smaller as it is closer to the periphery of the polishing surface. 3. The polishing pad according to claim 1, wherein a slurry holder is provided in the groove. 4. A polishing pad having a substantially circular polishing surface for polishing an object to be polished, wherein the polishing surface is provided with a groove extending from the center to a peripheral edge thereof, and a bottom surface of the groove is provided with a groove in the groove. Characterized in that the pleats are erected in such a manner as to divide them in the direction in which they extend. 5. The polishing pad according to claim 4, wherein the depth of the groove is smaller as it is closer to the periphery of the polishing surface. 6. The polishing pad according to claim 4, wherein a surface of the pleated body toward a center of the polishing surface is directed forward in a rotation direction of the polishing surface. 7. A belt-like polishing pad having a polishing surface for polishing an object to be polished, wherein an entire area of the polishing surface of the polishing pad is improper in a moving direction of the polishing surface and a width direction substantially perpendicular thereto. A polishing pad characterized by having continuous grooves. 8. The polishing pad according to claim 7, wherein the groove is formed to be shallower toward the rear in the direction of movement of the polishing surface. 9. The polishing pad according to claim 7, wherein a slurry holder is provided in the groove. 10. A belt-like polishing pad having a polishing surface for polishing an object to be polished, wherein a groove is provided on the entire polishing surface of the polishing pad, and a groove extends on the bottom surface of the groove. A polishing pad, wherein a pleated body is erected in a state of being divided in a direction. 11. A polishing method using a polishing pad in which a groove is provided in a polishing surface for polishing a body to be polished, wherein the polishing is performed by pressing the body to be polished against the polishing surface. A polishing method characterized by temporarily relaxing pressure on a polishing surface of a polishing body.