JPH11267961A - Abrasive pad, polishing device and polishing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the consumption of an abrasive slurry and improve the polished product by forming a groove having a prescribed width on an abrasive pad, and forming, within the groove, at least one resistor for raising the resistance when a liquid is carried in the extending direction of the groove. SOLUTION: A lattice groove 21 is formed on an abrasive pad base 20. A resistor for raising the resistance when a liquid is carried in the extending direction of the groove is formed in the groove 21. When an abrasive slurry is carried within the groove 21 in the extending direction of the groove, the resistance is raised to prevent the slurry from being carried out at once in discharge, so that the opportunity of the contact with a wafer can be increased. As the resistor in the groove 21, ribs 31 are formed at equal intervals in the groove 21 formed on the abrasive pad. The groove 21 is divided by the ribs 31 into a plurality of recessed parts 32 arranged in the extending direction of the groove. The abrasive slurry is caught in the divided recessed parts 32 without being carried out at ounce in the discharge along the groove 21, whereby the opportunity of the contact with the wafer can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In recent years, the miniaturization and high integration of semiconductor integrated circuits have progressed to the next generation in three years, and the design rules have been reduced by 70% of the previous generation. Has also been realized. In order to process a semiconductor device finely, for example, the gate width of a gate electrode of a transistor or the DR
It is necessary to reduce the area occupied by capacitors in AM, etc., and also to make the wiring part a multi-layer wiring structure. Is becoming important. As devices such as transistors and capacitors have a complicated structure and become three-dimensional, an interlayer insulating film has become thicker.

[0003] The above miniaturization has advanced the fine processing technology in the manufacturing process of semiconductor devices, and in particular, the technology of transferring a circuit pattern to a photosensitive organic film (photoresist) coated on a wafer surface using light. Has been achieved by increasing the resolution in the lithography process. Specifically, the light source used in the lithography process has a shorter wavelength. For example, a g line (436 nm) or i
Line (365 nm) is used, and i-line is mainly used for pattern transfer according to the 0.35 μm rule. In addition, for manufacturing a semiconductor integrated circuit having a rule of 0.25 μm or later, a technique of exposing using a KrF excimer laser (248.8 nm) or an ArF excimer laser (193 nm) has been developed.

[0004] As described above, the improvement of the resolution in the lithography step causes a decrease in the depth of focus (DOF) of the exposure in the lithography step. This improvement has to wait for the improvement of the resist performance, but the improvement of the resist performance is preceded by the demand for miniaturization. Therefore, a method of compensating for the lack of the depth of focus by minimizing the height difference of the device structure when performing the lithography process and reliably resolving a fine pattern without causing defocus has been studied.

Therefore, as a method of flattening the height difference of the device structure, recently, a chemical mechanical polishing method applying mirror finishing of a silicon wafer has been adopted. FIG.
FIG. 1 is a schematic view showing a conventional chemical mechanical polishing apparatus for performing this chemical mechanical polishing. This apparatus is used to sharpen the surface of a polishing pad 2 in which a polishing plate 3 supported on a rotating polishing plate rotating shaft 1 and having a polishing pad 2 adhered to a surface thereof, and a die 102 and the like formed by electrodeposition on a metal plate. A dresser 101, a carrier 5 holding a substrate 4 (hereinafter, referred to as a wafer) on which a layer to be polished such as an interlayer insulating film is formed by a wafer backing film 14, and a polishing slurry 10 are supplied onto the polishing pad 2. And a polishing slurry supply device 7 having a polishing slurry supply nozzle 6.

After dressing (grinding) the polishing pad 2 with a dresser 101, the polishing plate rotating shaft 1 and the carrier rotating shaft 8 are rotated, and the polishing slurry 10 is supplied from the polishing slurry supply nozzle 6 to the center of the polishing pad 2.
While the wafer 4 is being supplied,
Is pressed onto the polishing pad 2 to polish the wafer 4.

In the chemical mechanical polishing method as described above, micro-scratch occurs in a layer to be polished such as an insulating film of a wafer, and a variation in a polishing rate and a variation in a polishing amount within a wafer surface are large. That is the problem.

In order to suppress the occurrence of micro-scratch, shavings of the polishing pad 2 generated during dressing of the polishing pad 2, a diamond of a dresser, an interlayer film, debris of a wafer, a polished polishing slurry, etc. It is necessary to discharge these to the outside of the polishing pad 2.

Therefore, in the conventional chemical mechanical polishing apparatus described above, the polishing slurry is applied to the polishing pad 2 during the polishing operation.
A sufficient measure is taken such that the polishing slurry sufficiently removes or flushes out the polishing pad 2 with the polishing slurry.

In order to reduce the variation in the polishing rate and the variation in the polishing amount within the wafer surface, it is necessary to take the following measures. As a principle of the chemical mechanical polishing, a dresser makes countless scratches on the surface of the polishing pad 2 to form a so-called shallow dressing layer on the surface of the polishing pad 2, and the polishing slurry 10 enters the wafer while being held therein. By polishing the polishing pad 4, a sufficient polishing slurry can be supplied to the polishing surface of the wafer 4 pressed against the polishing pad 2,
Thus, polishing can be performed. In consideration of this, dressing of the polishing pad surface by a dresser, so-called dressing, is sufficiently performed so that the depth and density of the dressing layer are sufficient, and furthermore, sufficient polishing slurry 10 which is also a measure for preventing micro scratches is provided. The polishing slurry 10 is supplied to ensure that the polishing slurry 10 reaches the surface of the wafer 4. As described above, measures are taken to reduce the variation in the polishing rate and the variation in the polishing amount in the wafer surface.

[0011]

However, when a dressing layer is formed on the pad surface by dressing and a polishing slurry is supplied to perform polishing of the wafer, the polishing slurry is subjected to centrifugal force due to rotation of the polishing pad and the wafer. Is pushed out by pressing it against the polishing pad, and most is discharged out of the polishing pad without directly contributing to the polishing, so that an expensive polishing slurry is wasted. For this reason, as shown in FIG. 12, attempts have conventionally been made to cut, for example, a lattice-like groove 21 in the polishing pad base material 20 and store a polishing slurry there to increase the chance of contact with the wafer.

However, in the above-described structure, the problem that the polishing slurry is easily discharged out of the polishing pad and wastes the expensive polishing slurry remains. In order to improve this problem, a polishing pad in which a concentric groove 22 is cut with respect to the center of the polishing pad substrate 20 as shown in FIG. 13 has been considered. However, even in this case, the groove 2 is actually
The polishing slurry accumulated in 2 remains only on the outer peripheral side of the groove due to centrifugal force, and then is discharged out of the polishing pad, and the effect of increasing the chance of contact between the polishing slurry and the wafer is small, The problem of wasting expensive polishing slurries has not been solved.

As described above, the fact that the polishing slurry is discharged from the polishing pad without being effectively utilized increases the cost of chemical mechanical polishing, and the polishing slurry does not sufficiently contribute to polishing. There is a problem that polishing quality is deteriorated, such as generation of micro scratches on the surface and variation in polishing amount.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems. Therefore, the present invention relates to a conventional chemical mechanical polishing for flattening an interlayer insulating film in a semiconductor device manufacturing process. In addition to forming a random dressing layer of the polishing pad by dressing the pad with a dresser, the polishing slurry is prevented from being discharged to the outside of the polishing pad due to centrifugal force accompanying the rotation of the polishing pad, and the polishing slurry is formed on the polishing pad as much as possible. By not stopping, simply increasing the chance of contact between the wafer and the polishing slurry by supplying a large amount of the polishing slurry, but increasing the chance of the contact between the polishing slurry and the wafer efficiently with a smaller amount of the polishing slurry,
A groove whose shape is optimized is formed so that the polishing slurry can be effectively used for polishing, the original purpose,
Reduction of process costs by reducing the amount of polishing slurry used,
A polishing pad for chemical mechanical polishing capable of simultaneously improving the polishing quality such as the polishing shape, polishing rate and polishing uniformity of the wafer surface by increasing the chance of contact of the polishing slurry with the wafer, and It is an object to provide a polishing apparatus and a polishing method using the same.

[0015]

To achieve the above object, a polishing pad of the present invention is a polishing pad used for a polishing process by a chemical mechanical polishing method, wherein the polishing pad has a predetermined width. A groove is formed, and at least one resistor that increases resistance when a liquid flows in a direction in which the groove extends in the groove is formed.

In the polishing pad of the present invention, a groove having a predetermined width is formed, and at least one resistor for increasing resistance when a liquid flows in the groove extending direction is formed in the groove. Therefore, the resistance when the polishing slurry used for chemical mechanical polishing flows in the direction in which the grooves extend is increased. Accordingly, it is possible to suppress the polishing slurry from being discharged to the outside of the polishing pad due to the centrifugal force accompanying the rotation of the polishing pad, and it is possible to positively collect and hold the polishing slurry to be discharged. Also, since the polishing slurry is deteriorated by its use, the polishing is performed while supplying a new polishing slurry at the time of polishing.
The collected polishing slurry can not only be stored in the groove, but also a part of the deteriorated polishing slurry can be discharged. From these facts, it is possible to efficiently increase the chance of contact between the polishing slurry and the wafer with a smaller polishing slurry amount, thereby reducing the process cost, polishing the wafer surface, polishing speed, polishing uniformity, etc. It is possible to simultaneously improve quality.

The above polishing pad of the present invention is preferably
As the resistor, a partition that partitions the groove so as to form a plurality of recesses arranged in the direction in which the groove extends is formed, and more preferably, a cut is formed in the partition, or The partition has a portion at the same height as the surface of the polishing pad and a portion lower than the surface of the polishing pad. Also preferably, as the resistor,
A portion narrower than the predetermined width is formed in the groove. Preferably, a partition wall is formed substantially parallel to a side wall surface of the groove as the resistor. Also, preferably,
As the resistor, a protrusion is formed in the groove,
More preferably, the protrusion is formed on a bottom surface of the groove, the protrusion is formed on a side wall surface of the groove, or a plurality of the protrusions are formed, and between the protrusions The interval is 1 μm to 50 μm. Preferably, the resistor is formed in an inverted tapered shape in which the groove narrows toward the surface of the polishing pad. With the above-described resistor, it is possible to effectively suppress the discharge of the polishing slurry to the outside of the polishing pad due to the centrifugal force accompanying the rotation of the polishing pad.

The above polishing pad of the present invention is preferably
The grooves are formed in a lattice shape or a radial shape. Even in a polishing pad with a conventional groove, it is possible to effectively suppress the discharge of the polishing slurry to the outside of the polishing pad due to the centrifugal force caused by the rotation of the polishing pad by forming the resistor in the groove. Becomes

The above polishing pad of the present invention is preferably
The resistor is made of a material selected from urethane foam, silicone rubber, hard rubber, and a mixture thereof. In addition to forming a polishing pad having appropriate hardness and elasticity for polishing, it is possible to form a resistor having the above shape.

The above polishing pad of the present invention is preferably
With a predetermined radius of the polishing pad as a center, the polishing pad includes a first region on the rotation or traveling direction side of the polishing pad and a second region on the opposite side thereof, in a direction opposite to the rotation or traveling direction of the polishing pad. A groove having a convex portion is provided only on the second region side. Accordingly, when the polishing slurry is supplied to the center of the polishing pad while the polishing pad is rotated, the polishing slurry is discharged out of the polishing pad due to centrifugal force or the like due to the rotation of the polishing pad, The polishing slurry once received by the groove, and the polishing slurry once received can be selectively supplied to the front in the traveling direction of the wafer. Therefore,
The polishing slurry itself can be positively collected and held in the groove, and the polishing slurry can be selectively supplied to the wafer from the groove, so that the polishing slurry can be more effectively used during chemical mechanical polishing. Thus, it is possible to further reduce the process cost and to improve the polishing quality such as the polishing shape, the polishing speed and the polishing uniformity.

The above polishing pad of the present invention is preferably
The grooves formed in the polishing pad are constituted by a plurality of linear grooves. Preferably, the grooves formed in the polishing pad are arc-shaped grooves. The plurality of linear grooves or arc-shaped grooves can have a shape that is convex in the direction opposite to the rotation or traveling direction of the polishing pad.

The above polishing pad of the present invention is preferably
The groove formed in the polishing pad is constituted by a linear or arcuate groove, and has a plurality of convex portions in a direction opposite to the rotation or traveling direction of the polishing pad. The recovered polishing slurry can be selectively supplied to the wafer from the plurality of protrusions, so that the polishing slurry can more uniformly contact the wafer.

The above-mentioned polishing pad of the present invention is preferably
The groove formed in the polishing pad is constituted by a linear or arcuate groove, and has a protruding portion at the convex portion which protrudes in a direction opposite to the rotation or traveling direction of the polishing pad. It becomes easy to selectively supply the recovered polishing slurry to the wafer from the above-mentioned stretched portion, so that the polishing slurry can more uniformly contact the wafer.

The above polishing pad of the present invention is preferably
The groove formed in the polishing pad extends from the outer peripheral end of the polishing pad toward the center in a direction opposite to the rotation direction of the polishing pad, and is formed by a linear or arcuate groove. At least one extended portion protruding in the direction opposite to the rotation or traveling direction per groove
Or more. Since the grooves formed in the polishing pad extend from the outer peripheral end of the polishing pad toward the center in the direction opposite to the rotation direction of the polishing pad, the collected polishing slurry is discharged out of the polishing pad by centrifugal force. This makes it possible to reduce the amount of polishing slurry, the ability to hold the polishing slurry by the grooves is increased, the amount of polishing slurry used is reduced, and the chance of contact of the polishing slurry with the wafer can be increased. Further, it becomes easy to selectively supply the recovered polishing slurry to the wafer from the above-mentioned extended portion.

The above polishing pad of the present invention is preferably
Grooves formed in the polishing pad extend in a direction opposite to a rotation direction of the polishing pad toward a center from an outer peripheral end of the polishing pad, and a plurality of protrusions are formed in a direction opposite to a rotation or traveling direction of the polishing pad. Part. Since the grooves formed in the polishing pad extend from the outer peripheral end of the polishing pad toward the center in the direction opposite to the rotation direction of the polishing pad, the collected polishing slurry is discharged out of the polishing pad by centrifugal force. This makes it possible to reduce the amount of polishing slurry, the ability to hold the polishing slurry by the grooves is increased, the amount of polishing slurry used is reduced, and the chance of contact of the polishing slurry with the wafer can be increased. Further, the recovered polishing slurry can be selectively supplied to the wafer from the plurality of protrusions.

The above object can be achieved by the polishing apparatus and the polishing method using the polishing pad of the present invention.

[0027]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic view showing a chemical mechanical polishing apparatus according to the present invention. This apparatus is used to sharpen the surface of a polishing pad 2 in which a polishing plate 3 supported on a rotating polishing plate rotating shaft 1 and having a polishing pad 2 adhered to a surface thereof, and a die 102 and the like formed by electrodeposition on a metal plate. Dresser 1
01, a carrier 5 for holding a substrate 4 (hereinafter, referred to as a wafer) on which a layer to be polished such as an interlayer insulating film is formed by a wafer backing film 14, and polishing for supplying a polishing slurry 10 onto the polishing pad 2. And a polishing slurry supply device 7 having a slurry supply nozzle 6.

After dressing (grinding) the polishing pad 2 with the dresser 101, the polishing plate rotating shaft 1 and the carrier rotating shaft 8 are rotated, and the polishing slurry 10 is supplied from the polishing slurry supply nozzle 6 to the center of the polishing pad 2.
While the wafer 4 is being supplied,
Is pressed onto the polishing pad 2 to polish the wafer 4.

The polishing pad 2 has such a thickness that deformation during chemical mechanical polishing is sufficiently negligible, and has a hardness and elasticity suitable for polishing. As shown in FIG. 2A, a structure in which lattice-shaped grooves 21 are formed can be used. Here, a resistor that increases resistance when the liquid flows in the groove extending direction is formed in the groove 21. Thereby, the groove 21
When the polishing slurry 10 flows in the direction in which the grooves extend, the resistance increases, and when the polishing slurry 10 is discharged, the polishing slurry 10 does not flow out at once, and the chance of contact with the wafer 4 can be increased.

As the resistor in the groove 21, for example, as shown in FIG. 2 (b) as an enlarged schematic perspective view of the groove, partition walls 31 are formed at regular intervals in the groove 21 formed in the polishing pad. It can be formed and used. This partition 31
As a result, the groove 21 has a plurality of recesses 32 arranged in the extending direction of the groove.
Is divided into When the polishing slurry 10 is discharged along the groove 21, it does not flow out at once, but is captured by the divided concave portions 32, so that the chance of contact with the wafer 4 can be increased. Groove 21 of polishing pad
It has been found that the polishing slurry 10 accumulated in the surface remains only in the vicinity of the side wall due to the centrifugal force and flows out thereafter. FIG.
As shown in (b), by increasing the side wall as much as possible, the polishing slurry remaining on the side wall can be increased,
The effect of increasing the total amount of polishing slurry held on the polishing pad 2 as much as possible can be obtained.

The resistors in the groove 21 include:
As shown in FIG. 3 (a), the partition 21 divides the groove 21 into a plurality of recesses 32 arranged in the extending direction of the groove.
A so-called gate structure in which the partition walls 33 touch each other can be used. Thus, when the polishing slurry is newly supplied or receives a centrifugal force, the polishing slurry is not subjected to the second operation.
The so-called gate formed by the contact of the partition walls 33 is pushed open to discharge the used polishing slurry, and otherwise, the gate is closed to supply the polishing slurry for polishing with the wafer. Thereby, there is an effect that the polishing slurry is held in the plurality of concave portions 32 arranged in the extending direction of the groove.

The resistors in the groove 21 are as follows.
As shown in FIG. 3 (b), a partition wall 35 in which a notch 36 is partially formed in the center upper portion can be used as a partition wall that divides the groove 21 into a plurality of concave portions 32 arranged in the extending direction of the groove.
Thus, when the polishing slurry is newly supplied or subjected to centrifugal force, the polishing slurry supplies a new polishing slurry from the partially cut-out portion 36 at the upper center of the partition wall 35 and at the same time overflows the used polishing slurry. It functions to discharge and discharge and replace the polishing slurry.

As the polishing pad having the structure shown in FIGS. 2 (b), 3 (a) and 3 (b), female dies having the above-mentioned respective patterns are pressed against a polishing pad material heated to a melting temperature or higher. It can be formed by a method in which a polishing pad material melted into a liquid state is poured into a female mold having the above-mentioned respective patterns and solidified to form the polishing pad material. The polishing pad can be formed from a material selected from, for example, foamed polyurethane, non-foamed polyurethane, silicone resin, Teflon, vinyl chloride, hard rubber, and a mixture thereof. Can be formed by using a material selected from urethane foam, silicone rubber, hard rubber, and a mixture thereof.

The resistors in the groove 21 include:
As shown in FIG. 4A, a groove 37 having a predetermined width formed in the polishing pad has a portion 37 smaller than the predetermined width.
Are formed at equal intervals. This has the effect of increasing the resistance of the polishing slurry flowing through the grooves of the polishing pad and retaining the polishing slurry.

The resistors in the groove 21 include:
As shown in FIG. 4B, by forming a new partition wall 38 vertically in the center of the groove 21, the groove 21 can be substantially divided into a plurality of grooves 39. This has the effect of increasing the total length of the side wall on which the polishing slurry is stored and increasing the holding amount of the polishing slurry.

The resistors in the groove 21 include:
As shown in FIG. 5A, a structure in which the protrusion 40 is provided on the bottom surface of the groove 21 can be adopted. The projections 40 have the effect of increasing the resistance of the polishing slurry when flowing through the groove 21 and at the same time increasing the side wall area, thereby increasing the holding amount of the polishing slurry.

As the resistor in the groove 21,
As shown in FIG. 5B, a structure in which the protrusions 41 are provided on one or both side wall surfaces of the groove 21 can be adopted. Similarly to the above, the resistance of the polishing slurry when flowing through the groove 21 is increased, and at the same time, the side wall area is increased, which has the effect of increasing the holding amount of the polishing slurry. Further, since a large foreign substance in the polishing slurry is trapped here so that the foreign substance does not appear on the polishing pad surface, scratches and the like in polishing can be prevented, and the polishing quality can be improved.

As shown in FIGS. 5 (a) and 5 (b), in the case where the projections are formed in the grooves 21, the interval between the projections is preferably 1 μm to 50 μm. . If the spacing between the projections is too small, the resistance when the polishing slurry flows will be too high, and the deteriorated polishing slurry may not be discharged promptly.If the spacing between the projections is too wide, the projection slurry may be provided. The effect of increasing the resistance when flowing is reduced.

The resistors in the groove 21 are as follows.
As shown in FIG. 6, a structure in which the groove 21 is formed in an inverted tapered shape narrowing toward the surface side of the polishing pad can be employed. The drawing has a structure having a partition wall 31 for further dividing the groove 21 into a plurality of concave portions 32 arranged in the extending direction of the groove. By forming the groove in the inversely tapered shape, the holding amount of the polishing slurry can be increased.

4 (a), 4 (b), 5 (a),
(B) and the polishing pad having the structure shown in FIG.
Using a method and material similar to the above, a method of forming by pressing a female mold having the above-described pattern on a polishing pad material heated to a melting temperature or higher, and polishing the molten polishing pad material to a liquid state in each of the above. A method of casting and solidifying by pouring into a female mold with a pattern, or
It can be formed by a method of pouring into a female mold and solidifying, and then dissolving and forming the female mold.

In the present embodiment, the shape of the grooves formed in the polishing pad substrate 20 as the polishing pad 2 is not particularly limited. In addition to the lattice-shaped grooves shown in FIG. It is possible to have grooves of the shape shown. The polishing pad shown in FIG. 7 has a concentric groove 22 formed with respect to the center of the polishing pad substrate 20. Here, similarly to the above, by adopting a structure in which a resistor that increases resistance when a liquid flows in the groove extending direction is formed in the groove, polishing is also performed on a groove having a conventional shape in the same manner as described above. The resistance of the polishing slurry flowing through the groove of the pad is increased, and the discharge of the polishing slurry to the outside of the polishing pad due to the centrifugal force accompanying the rotation of the polishing pad can be effectively suppressed. .

Also, as described below, FIGS.
As shown in the figure, with a predetermined radius of the polishing pad as the center,
A first region on the rotation or traveling direction side of the polishing pad and a second region on the opposite side thereof, wherein a groove having a convex portion in a direction opposite to the rotation or traveling direction of the polishing pad is formed on the second region side. A polishing pad having only the polishing pad is also preferably used. Accordingly, when the polishing slurry is supplied to the center of the polishing pad while the polishing pad is rotated, the polishing slurry is discharged out of the polishing pad due to centrifugal force or the like due to the rotation of the polishing pad, The polishing slurry once received by the groove, and the polishing slurry once received can be selectively supplied to the front in the traveling direction of the wafer. Therefore, the polishing slurry itself can be positively collected and held in the groove, and the polishing slurry can be selectively supplied to the wafer from the groove, so that the polishing slurry can be more effectively used during chemical mechanical polishing. As a result, it is possible to further reduce the process cost and to improve the polishing quality such as the polishing shape, polishing speed and polishing uniformity.

In the polishing pad shown in FIG. 8, the shape of the groove 23 formed in the polishing pad substrate 20 is set so that the groove 23 is formed in the polishing pad advancing direction toward the outer peripheral end of the polishing pad with respect to the rotation direction 30 of the polishing pad. The groove formed in the polishing pad at the portion of the line 301 through which the center of the wafer to be polished passes is most convex 203
The groove of the polishing pad is formed such that

When the polishing pad is rotated while supplying the polishing slurry to the central portion 210 of the polishing pad, the polishing slurry spreads by centrifugal force toward the outer periphery of the polishing pad. However, the polishing pad of this embodiment is used. Then, the polishing slurry which tends to flow out of the polishing pad by centrifugal force is positively collected in the groove 23, and the collected polishing slurry is re-emitted from only the most convex groove 203 to the rear in the polishing pad rotation direction. And selectively supplied to the wafer to be polished passing therethrough. Thus, the polishing slurry is sufficiently supplied in polishing the wafer to be polished, so that the polishing slurry can be effectively used and the polishing quality can be improved.

In the polishing pad shown in FIG. 9, the shape of the groove 24 formed in the polishing pad substrate 20 is changed so that the groove formed in the polishing pad at the line 301 through which the center of the wafer to be polished passes is in the opposite direction of the polishing pad. In the same manner as described above, the polishing slurry is sufficiently supplied in the polishing of the wafer to be polished, thereby effectively utilizing the polishing slurry and improving the quality of the polishing. Becomes possible.

In the polishing pad shown in FIG. 10, the shape of the groove 25 formed in the polishing pad base 20 is set so that the groove 25 is formed in the direction of travel of the polishing pad toward the outer periphery of the polishing pad with respect to the rotation direction 30 of the polishing pad. The grooves formed in the polishing pad at the portions of the plurality of lines 302 through which the wafer to be polished pass are most convex 20 in the direction in which the polishing pad moves in the reverse direction.
5, the polishing slurry is supplied to the wafer to be polished from a plurality of positions, and the polishing quality such as polishing speed and in-plane uniformity is further improved. Effective utilization is further promoted.

In the polishing pad shown in FIG. 11, the shape of the groove 26 formed in the polishing pad substrate 20 is such that the groove formed in the polishing pad at the line 302 where the wafer to be polished passes has a plurality of grooves in the direction in which the polishing pad moves in the reverse direction. It is formed of straight lines so as to form the convex corners 206, and the polishing slurry can be supplied to the wafer to be polished from a plurality of locations, similarly to the polishing pad shown in FIG.

In the polishing pad shown in FIG. 12, a groove extending portion 220 serving as a port for re-discharging the polishing slurry is formed on the convex portion 204 of the groove pattern of the polishing pad shown in FIG. In two opposite directions. The polishing slurry supplied to the central portion 210 of the polishing pad and spread toward the outer periphery of the polishing pad by centrifugal force due to the rotation of the polishing pad and discharged is positively collected in the groove 24, and the accumulated polishing slurry is most convex. The polishing slurry can be reliably ejected to a plurality of locations from the extending portion 220 of the groove which becomes a polishing slurry discharge port newly provided in the groove portion 204 which has been newly formed. In the groove pattern of the polishing pad, even if only one projection is formed, it is possible to obtain 2
It is possible to supply to more than one place, and it is possible to improve the polishing quality of the wafer to be polished and to effectively use the polishing slurry.

In the polishing pad shown in FIG. 13, the shape of the groove 27 formed in the polishing pad base 20 is a scroll (spiral) type. This makes it possible to capture the polishing slurry more reliably when discharging the polishing slurry. Further, a groove extending portion 230 serving as a port for discharging the polishing slurry is provided, and the polishing slurry captured from the groove is released again. In the same manner as described above, in the scroll-shaped groove 27, a groove extending portion 230 serving as a polishing slurry discharge port is provided at the intersection of the scroll-shaped groove 27 and the region 302 through which the wafer to be polished passes. The polishing slurry is re-emitted toward the wafer to be polished, and the polishing slurry is supplied to the wafer to be polished from a plurality of locations, so that the polishing quality can be further improved and the polishing slurry can be effectively used.

Any of the polishing pads having the above-described shapes can be used by being incorporated into the polishing apparatus shown in FIG. 1, and the substrate to be processed is chemically and mechanically polished using this polishing apparatus. Processing can be performed.

[0052]

As described above, according to the polishing pad of the present invention, in chemical mechanical polishing for flattening an interlayer insulating film in a semiconductor device manufacturing process, centrifugal force accompanying rotation of the polishing pad is used. Suppresses the discharge of the polishing slurry to the outside of the polishing pad, increases the chance of efficient contact between the polishing slurry and the wafer with a smaller amount of polishing slurry, reduces the processing cost by reducing the amount of polishing slurry used, and reduces the polishing slurry wafer It is possible to simultaneously improve the polishing quality such as the polishing shape, polishing rate, and polishing uniformity of the wafer surface by increasing the chance of contact with the wafer.

Further, the polishing pad of the present invention can be used by being incorporated in a polishing apparatus, and it is possible to perform chemical mechanical polishing of a substrate to be processed by using this polishing apparatus. It is possible to simultaneously reduce the process cost by reducing the amount and improve the polishing quality such as the polishing shape and polishing uniformity of the wafer surface by increasing the chance of the polishing slurry coming into contact with the wafer.

[Brief description of the drawings]

FIG. 1 is a schematic view of a chemical mechanical polishing apparatus according to the present invention and a conventional example.

FIG. 2A is a schematic view showing a groove pattern of a polishing pad according to an embodiment of the present invention, and FIG. 2B is a schematic perspective view in which the groove is enlarged.

FIGS. 3A and 3B are schematic perspective views in which grooves of a polishing pad according to an embodiment of the present invention are enlarged.

FIGS. 4A and 4B are schematic perspective views in which grooves of a polishing pad according to an embodiment of the present invention are enlarged.

FIGS. 5A and 5B are schematic perspective views in which grooves of the polishing pad according to the embodiment of the present invention are enlarged.

FIG. 6 is an enlarged schematic perspective view of a groove portion of the polishing pad according to the embodiment of the present invention.

FIG. 7 is a schematic view showing a groove pattern of the polishing pad according to the embodiment of the present invention.

FIG. 8 is a schematic diagram showing a groove pattern of the polishing pad according to the embodiment of the present invention.

FIG. 9 is a schematic view showing a groove pattern of the polishing pad according to the embodiment of the present invention.

FIG. 10 is a schematic diagram showing a groove pattern of a polishing pad according to an embodiment of the present invention.

FIG. 11 is a schematic view showing a groove pattern of the polishing pad according to the embodiment of the present invention.

FIG. 12 is a schematic view showing a groove pattern of the polishing pad according to the embodiment of the present invention.

FIG. 13 is a schematic diagram showing a groove pattern of the polishing pad according to the embodiment of the present invention.

FIG. 14 is a schematic view showing a groove pattern of a polishing pad according to a conventional example.

FIG. 15 is a schematic view showing a groove pattern of a polishing pad according to a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Polishing plate rotating shaft, 2 ... Polishing pad, 3 ... Polishing plate, 4 ... Substrate to be processed (wafer), 5 ... Carrier,
6: polishing slurry supply nozzle, 7: polishing slurry supply device,
8 Carrier rotating shaft 9 Polishing pressure adjustment mechanism 10 Polishing slurry 11 Dresser applied pressure 14 Wafer backing film 20 Polishing pad base 21
2, 23, 24, 25, 26, 27, 39 ... groove, 30 ...
Polishing pad rotation direction, 31, 33, 35, 38 ... partition wall,
32 ... recess, 34 ... notch, 36 ... notch, 37 ...
.., Protrusions, 101,.
Dresser, 102: Dresser diamond, 103: Dressing layer of polishing pad by dress, 203, 204, 2
05,206 ... convex part, 210 ... polishing pad center, 22
0, 230: extending portion of groove, 301: locus of center of wafer to be polished, 302: passage area excluding edge of wafer to be polished.

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[Procedure amendment]

[Submission date] December 25, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Change

[Correction contents]

As the polishing pad having the structure shown in FIGS. 2 (b), 3 (a) and 3 (b), female dies having the above-mentioned respective patterns are pressed against a polishing pad material heated to a melting temperature or higher. It can be formed by a method in which a polishing pad material melted into a liquid state is poured into a female mold having the above-mentioned respective patterns and solidified to form the polishing pad material. Further, the polishing pad can be formed, for example, from a material selected from foamed polyurethane, non-foamed polyurethane, silicone resin, polyfluoroethylene-based resin , vinyl chloride, hard rubber, and a mixture thereof. The resistor in the groove 21 can be formed using a material selected from urethane foam, silicon rubber, hard rubber, and a mixture thereof.

Claims (46)

[Claims] 1. A polishing pad used in a polishing process by a chemical mechanical polishing method, wherein a groove having a predetermined width is formed in the polishing pad, and a liquid flows in the groove in a direction in which the groove extends. A polishing pad on which at least one resistor for increasing the resistance is formed. 2. The polishing pad according to claim 1, wherein a partition partitioning said groove so as to form a plurality of concave portions arranged in a direction in which said groove extends is formed as said resistor. 3. The polishing pad according to claim 2, wherein a cut is formed in said partition. 4. The polishing pad according to claim 2, wherein the partition has a portion having the same height as the surface of the polishing pad and a portion lower than the surface of the polishing pad. 5. The polishing pad according to claim 1, wherein a portion narrower than said predetermined width is formed in said groove as said resistor. 6. The polishing pad according to claim 1, wherein a partition wall is formed substantially parallel to a side wall surface of the groove as the resistor. 7. The polishing pad according to claim 1, wherein a projection is formed in said groove as said resistor. 8. The polishing pad according to claim 7, wherein said projection is formed on a bottom surface of said groove. 9. The polishing pad according to claim 7, wherein said projection is formed on a side wall surface of said groove. 10. The polishing pad according to claim 7, wherein a plurality of said projections are formed, and an interval between said projections is 1 μm to 50 μm. 11. The polishing pad according to claim 1, wherein the groove is formed as an inversely tapered shape in which the groove narrows toward the surface of the polishing pad. 12. The polishing pad according to claim 1, wherein said grooves are formed in a grid or radial pattern. 13. The polishing pad according to claim 1, wherein said resistor is made of a material selected from urethane foam, silicon rubber, hard rubber, and a mixture thereof. 14. A polishing pad according to claim 1, further comprising: a first region on the polishing pad rotation or traveling direction side and a second region on the opposite side of the polishing pad centering on a predetermined radius of the polishing pad. 2. The polishing pad according to claim 1, wherein a groove having a convex portion in a direction opposite to the direction is provided only on the second region side. 15. The polishing pad according to claim 14, wherein the groove formed in the polishing pad is constituted by a plurality of linear grooves. 16. A polishing pad according to claim 14, wherein the groove formed in said polishing pad is constituted by an arc-shaped groove. 17. The polishing pad according to claim 17, wherein the groove formed in the polishing pad is a linear or arcuate groove, and has a plurality of projections in a direction opposite to the rotation or traveling direction of the polishing pad. Item 15. The polishing pad according to Item 14. 18. A groove formed in the polishing pad is constituted by a linear or arcuate groove, and has an extended portion protruding in a direction opposite to the rotation or traveling direction of the polishing pad at the projection. The polishing pad according to claim 14, wherein 19. A groove formed in the polishing pad,
An extension extending from the outer peripheral end of the polishing pad toward the center in a direction opposite to the rotation direction of the polishing pad, and configured by a linear or arcuate groove, and protruding in a direction opposite to the rotation or traveling direction of the polishing pad. 15. The polishing pad according to claim 14, wherein the polishing pad has at least one portion per one groove. 20. A groove formed in the polishing pad,
15. The polishing pad according to claim 14, wherein the polishing pad extends in a direction opposite to a rotation direction of the polishing pad from an outer peripheral end toward a center, and has a plurality of protrusions in a direction opposite to a rotation or traveling direction of the polishing pad. Polishing pad. 21. A polishing apparatus having a polishing pad for performing a polishing process by a chemical mechanical polishing method, wherein a groove having a predetermined width is formed in the polishing pad, and the groove is formed in the groove. A polishing apparatus having at least one resistor for increasing resistance when a liquid flows in a stretching direction. 22. The polishing apparatus according to claim 21, wherein a partition partitioning the groove so as to form a plurality of concave portions arranged in a direction in which the groove extends is formed as the resistor. 23. The polishing apparatus according to claim 22, wherein a notch is formed in said partition. 24. The polishing apparatus according to claim 22, wherein the partition has a portion having the same height as the surface of the polishing pad and a portion lower than the surface of the polishing pad. 25. The polishing apparatus according to claim 21, wherein a portion smaller than said predetermined width is formed in said groove as said resistor. 26. The polishing apparatus according to claim 21, wherein a partition wall is formed substantially parallel to a side wall surface of said groove as said resistor. 27. The polishing apparatus according to claim 21, wherein a projection is formed in said groove as said resistor. 28. The polishing apparatus according to claim 27, wherein said projection is formed on a bottom surface of said groove. 29. The polishing apparatus according to claim 27, wherein said projection is formed on a side wall surface of said groove. 30. A plurality of protrusions are formed, and an interval between the protrusions is 1 μm to 50 μm.
The polishing apparatus according to the above. 31. The polishing apparatus according to claim 21, wherein, as the resistor, the groove is formed in an inversely tapered shape such that the groove becomes narrower toward the surface of the polishing pad. 32. The polishing apparatus according to claim 21, wherein said grooves are formed in a grid or radial pattern. 33. A polishing apparatus according to claim 21, wherein said resistor is made of a material selected from urethane foam, silicone rubber, hard rubber and a mixture thereof. 34. A polishing method for performing a polishing process by a chemical mechanical polishing method using a polishing pad, wherein a groove having a predetermined width is formed in the polishing pad as the polishing pad. A polishing method using a polishing pad on which at least one resistor for increasing resistance when a liquid flows in the direction in which the groove extends is formed. 35. The polishing method according to claim 34, wherein a polishing pad having a partition partitioning said groove so as to form a plurality of concave portions arranged in a direction in which said groove extends is used as said resistor. 36. The polishing method according to claim 35, wherein a polishing pad in which a cut is formed in said partition is used. 37. The polishing method according to claim 35, wherein the partition wall uses a polishing pad having a portion having the same height as the surface of the polishing pad and a portion lower than the surface of the polishing pad. 38. The polishing method according to claim 34, wherein a polishing pad in which a portion smaller than the predetermined width is formed in the groove is used as the resistor. 39. The polishing method according to claim 34, wherein a polishing pad having a partition wall substantially parallel to a side wall surface of said groove is used as said resistor. 40. The polishing method according to claim 34, wherein a polishing pad having a projection formed in said groove is used as said resistor. 41. The polishing method according to claim 40, wherein a polishing pad is used in which said projection is formed on a bottom surface of said groove. 42. The polishing method according to claim 40, wherein a polishing pad is used in which said projection is formed on a side wall surface of said groove. 43. The polishing method according to claim 40, wherein a plurality of said projections are formed, and a polishing pad having an interval between said projections of 1 μm to 50 μm is used. 44. The polishing method according to claim 34, wherein a polishing pad in which said groove is formed in an inversely tapered shape in which said groove narrows toward the surface side of said polishing pad is used as said resistor. 45. The polishing method according to claim 34, wherein said grooves use a polishing pad formed in a grid or radial pattern. 46. The polishing method according to claim 34, wherein said resistor uses a polishing pad formed of a material selected from urethane foam, silicone rubber, hard rubber and a mixture thereof.