KR20070037683A - Abrasive pad and abrasive apparatus - Google Patents

Abstract

An object of the present invention is to provide a polishing pad and a polishing apparatus capable of prolonging the life of the polishing pad and improving the in-plane uniformity and at the same time preventing the polishing object from adhering to the polishing pad.

The pad-shaped pad main body 21 having one surface as the polishing surface 22 and the other surface as the supporting surface 23 and the pad body 21 penetrating from the polishing surface 22 to the supporting surface 23 A plurality of hole portions 30 formed by combining a plurality of elongated holes 31 provided along a plurality of different directions in the plane direction of the polishing surface 22 are provided.

Polishing apparatus, pad body, semiconductor wafer, polishing pad, surface plate

Description

Polishing Pads & Polishing Devices {ABRASIVE PAD AND ABRASIVE APPARATUS}

1 is a side view showing a polishing apparatus in which a polishing pad according to a first embodiment of the present invention is assembled.

FIG. 2 is a plan view showing a polishing pad assembled to the polishing apparatus of FIG.

3 is a plan view showing a first modification of the polishing pad of FIG.

4 is a plan view showing a second modification of the polishing pad of FIG.

FIG. 5 is a plan view showing a third modification of the polishing pad of FIG. 1; FIG.

FIG. 6 is a plan view showing a fourth modification of the polishing pad of FIG. 1; FIG.

7 is a plan view showing a fifth modification of the polishing pad of FIG.

8 is a plan view showing a sixth modification of the polishing pad of FIG.

9 is a plan view showing a seventh modification of the polishing pad of FIG.

10 is a plan view showing an eighth modification of the polishing pad of FIG.

11 is a plan view showing a ninth modification of the polishing pad of FIG.

12 is a plan view showing a tenth modification of the polishing pad of FIG.

FIG. 13 is a plan view showing an eleventh modification of the polishing pad of FIG.

14 is a plan view showing a twelfth modification of the polishing pad of FIG.

15 is an explanatory diagram showing an operating range of the polishing apparatus of FIG.

Fig. 16 is a plan view showing a polishing pad and a semiconductor wafer provided with through holes.

Fig. 17 is a sectional view showing a main part of the polishing pad of Fig. 1;

18 is a plan view showing a polishing pad and a semiconductor wafer provided with polishing grooves.

Fig. 19 is a sectional view showing a main part of the polishing pad of Fig. 1;

<Explanation of symbols for the main parts of the drawings>

10: polishing device

12: surface plate

13: holding mechanism

20, 20A to 20M: Polishing Pad

21: pad body

22: polishing surface

23: support surface

30: hole

31: long hole

W: semiconductor wafer

[Document 1] Japanese Patent Publication No. 62-34509

[Document 2] Japanese Unexamined Patent Publication No. 2000-33553

[Document 3] Japanese Unexamined Patent Publication No. 2003-300149

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polishing pad and a polishing apparatus for a semiconductor wafer used in chemical mechanical polishing performed in a semiconductor device manufacturing process, and more particularly, to a long life of a polishing pad and high precision flattening.

The polishing pad is subjected to chemical mechanical polishing when the surface of the insulating film of the wafer is planarized in the semiconductor device manufacturing process. The polishing surface of the polishing pad used in this chemical mechanical polishing is planar, and the polishing surface of the wafer and the polishing surface of the polishing pad are arranged in parallel to perform polishing by contacting while rotating with each other, and various polishing apparatuses are used.

For example, in the polishing pad 100 as shown in Figs. 16 and 17, a plurality of through holes 102 penetrating the polishing pad are arranged on the surface of the polishing pad 101 made of foamed urethane or the like. The polishing pad 110 as shown in FIG. 18 and FIG. 19 has a lattice polishing groove 112 formed on the surface of the polishing pad 111 to impart the effect of supplying and discharging the polishing liquid or ejecting the polishing chip (Example For example, see patent documents 1-3). In these figures, W represents a wafer. Moreover, the grinding | polishing groove | channel is also known as a concentric circular shape. There is also a polishing pad in which a polishing groove and a through hole are combined. Since the polishing pad in which the polishing groove is formed has a high supply and discharge capacity of the polishing liquid, there is an effect that the variation in the amount of polishing between the center of the wafer and the end of the wafer is small. In addition, when peeling the wafer from the polishing pad, air enters the center of the wafer along the groove, so that the wafer is easily peeled off.

[Patent Document 1] Japanese Patent Publication No. 62-34509

[Patent Document 2] Japanese Patent Application Laid-Open No. 2000-33553

[Patent Document 3] Japanese Unexamined Patent Publication No. 2003-300149

The polishing pad described above has the following problems. That is, in the case of the polishing groove, if the polishing groove disappears due to the shaping of the urethane foam, the effect of supplying or discharging the polishing liquid and ejecting the polishing chip is not expected and the life of the polishing pad is reached. Since the depth of the polishing groove is generally about half the thickness of the polishing pad, there is a problem that the life is short. In addition, when the depth of the polishing groove reaches the back side of the polishing pad, the polishing pad is separated and cannot be used.

On the other hand, the polishing pad provided with the through hole can be used until just before the polishing pad disappears, and thus has a long life. However, since the supply discharge capability of the polishing liquid is low, there is a problem that the variation in the polishing amount between the wafer center and the wafer end is large. In addition, when peeling the wafer from the polishing pad, air cannot be supplied to the center of the wafer, which causes a problem of being difficult to peel. In addition, there was a problem that the wafer adhered to the polishing pad during polishing, and the wafer was easily protruded from the wafer carrier.

Accordingly, an object of the present invention is to provide a polishing pad and a polishing apparatus capable of prolonging the life of the polishing pad and improving the in-plane uniformity and preventing the polishing object from adhering to the polishing pad.

In order to solve the above problems and achieve the object, the polishing pad and the polishing apparatus of the present invention are configured as follows.

A polishing pad for polishing a workpiece, comprising: a plate-shaped pad body whose one surface is a polishing surface and the other surface as a supporting surface, and the pad body penetrates from the polishing surface to the supporting surface, and the surface of the polishing surface It is characterized by including a plurality of hole portions formed by combining a plurality of long holes extending along a plurality of different directions in a direction.

Further, the polishing pad provided on the surface plate, a holding member disposed opposite to the polishing pad to hold the polishing object, and a polishing object held by the polishing pad and the holding member are subjected to relative frictional movement. And a drive mechanism for polishing the surface to be polished, wherein the polishing pad includes a plate-shaped pad body having one surface polished and the other surface supported by the surface plate; It is characterized by including a plurality of holes formed by combining a plurality of elongated holes penetrating up to the support surface and extending along a plurality of different directions in the plane direction of the polishing surface.

1 is a side view showing the polishing apparatus 10 according to the first embodiment of the present invention, and FIG. 2 is a plan view of the polishing pad 20 assembled to the polishing apparatus 10.

The polishing apparatus 10 includes a rotation drive mechanism 11, a surface plate 12 provided on the rotation drive mechanism 11, a holding mechanism 13 disposed opposite to the surface plate 12, and the holding device. It is provided with the movement mechanism 14 which moves the sphere 13 on the surface 12, and moves the upper surface of the surface plate 12 along the upper surface of the surface plate 12, and the nozzle 15 which supplies polishing liquid on the surface plate 12. Doing.

A detachable polishing pad 20 is provided on the upper surface of the surface plate 12, and the holding mechanism 13 is provided with a semiconductor wafer W as an abrasive.

The polishing pad 20 includes, for example, a pad body 21 made of a resin such as foamed polyurethane or urethane, and one surface of the pad body 21 faces upward as the polishing surface 22, and the other The side surface is provided on the surface plate 12 as the support surface 23.

The hole part 30 penetrates from the grinding | polishing surface 22 to the support surface 23 side, ie, the thickness direction of the pad main body 21. The hole part 30 is formed using a punching process etc., for example. As shown in Fig. 2, the hole portion 30 is formed by ten crosses in which four long holes 31 are radially combined as viewed from the polishing surface 22 side. That is, the hole 30 is formed by combining a plurality of long holes 31 provided along the plurality of different directions in the plane direction (direction along the surface) of the polishing surface 22.

In addition, the external shape of the hole part 30 is 5 mm or more and 300 mm or less, for example. In addition, the width | variety of the long hole 31 is 1 mm or more and 8 mm or less, for example. In addition, the distance between adjacent hole parts 30 is 2 times or less of the external shape of the hole part 30. FIG.

According to the polishing pad 20 configured as described above, since the hole portion 30 is provided in a combination of a plurality of long holes, the sealing property between the polished surface of the semiconductor wafer W and the surface of the polishing pad 1 is lowered. Since a reduced pressure becomes difficult to occur, it becomes easy to remove the to-be-polished material from the surface of the polishing pad 1 after completion of polishing.

In addition, since the hole portion 30 is formed to penetrate the pad body 21 in the thickness direction, the pad life is extended by taking a long period until the pad body 21 wears and the hole portion 30 disappears. The frequency of replacement of the polishing pad 20 can be reduced. In addition, since the outlet of the polishing liquid to the hole 30 is increased, polishing is stabilized and surface uniformity is improved.

In addition, as in the case where the polishing groove is formed, the hole portion 30 does not flow out of the polishing pad through the groove and stops the polishing liquid therein, thereby reducing the amount of polishing liquid to be used.

Moreover, since the hole part 30 is a through hole, it can form by punching process and manufacturing cost becomes cheaper than the polishing pad which has the groove | channel formed by cutting process.

As described above, according to the polishing apparatus 10 using the polishing pad 20 according to the present embodiment, it is possible to improve the in-plane uniformity and to prevent the adhesion of the wafer to the polishing pad while improving the life of the polishing pad 20. have.

In addition, the polishing pad 20 may use the pad body of the single layer of foamed urethane as mentioned above, but may use the laminated structure by which the soft nonwoven fabric adhered below the layer of foamed urethane (the surface 12 side). good. In the case of the laminated structure, the hole 30 is formed only in the urethane foam layer.

3 is a plan view showing a polishing pad 20A according to a first modification of the polishing pad 20 described above. In this modification, the hole 40 is provided instead of the hole 30. Three long holes 41 are provided in the hole part 40. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

4 is a plan view showing a polishing pad 20B according to a second modification of the polishing pad 20 described above. In this modification, the hole 50 is provided instead of the hole 30. The five long holes 51 are provided in the hole part 50. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

FIG. 5 is a plan view showing a polishing pad 20C according to a third modification of the polishing pad 20 described above. In this modification, the hole 60 is provided instead of the hole 30. The six long holes 61 are provided in the hole part 60. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

FIG. 6 is a plan view showing a polishing pad 20D according to a fourth modification of the polishing pad 20 described above. In the present modification, the hole 30 is formed in a different arrangement from the polishing pad 20. That is, the hole part 30 is arrange | positioned in engagement with the adjacent hole part 30 in the range which the pad main body 21 does not separate. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

FIG. 7 is a plan view showing a polishing pad 20E according to a fifth modification of the polishing pad 20 described above. In this modification, the communication hole 32 is provided in the hole part 30. Since the communication hole 32 is provided, the polishing liquid can move freely between the hole portions 30, and evenly spreads evenly over the entire polishing pad 20E. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

8 is a plan view showing a polishing pad 20F according to a sixth modification of the polishing pad 20 described above. In the present modification, the hole 30 is formed in a different arrangement from the polishing pad 20. That is, the long holes 31 of the nearest hole parts 30 are arrange | positioned so that they may not be located on the same straight line. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

9 is a plan view showing a polishing pad 20G according to a seventh modification of the polishing pad 20 described above. In the present modification, the hole 30 is formed in a different arrangement from the polishing pad 20. That is, the hole part 30 is arrange | positioned concentrically from the center of the pad main body 21. FIG. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

FIG. 10 is a plan view showing a polishing pad 20H according to an eighth modification of the polishing pad 20 described above. In the present modification, the hole 30 is formed in a different arrangement from the polishing pad 20. That is, the hole part 30 is arrange | positioned at random. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

11 is a plan view showing a polishing pad 20I according to a ninth modification of the polishing pad 20 described above. In this modified example, the hole part 30 and the hole part 33 similar to the hole part 30 and small in size are provided. The hole part 33 is provided with four long holes 34 shorter than the long hole 31. The hole part 30 and the hole part 33 are alternately arrange | positioned. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

12 is a plan view showing a polishing pad 20J according to a tenth modification of the polishing pad 20 described above. In this modification, the hole part 30 and the hole part 70 of the shape different from the hole part 30 are provided. The hole 70 is provided with four arc-shaped long holes 71. The hole part 30 and the hole part 70 are alternately arrange | positioned. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

FIG. 13 is a plan view showing a polishing pad 20K according to an eleventh modification of the polishing pad 20 described above. In this modification, the hole 80 is provided instead of the hole 30. The hole 80 is provided with two long holes 81 but is radial but inequality. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

14 is a plan view showing a polishing pad 20L according to a twelfth modification of the polishing pad 20 described above. In this modification, the hole 90 is provided instead of the hole 30. The hole 90 is provided with four arc-shaped long holes 91. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

15 is an explanatory diagram showing an operation range in the polishing pad 20M and the polishing apparatus 10 according to the twelfth modification of the polishing pad 20 described above. In this modification, the hole 30 is provided similarly to the polishing pad 20. Moreover, even if it is arrange | positioned in the outer peripheral part of the pad main body 21 among the hole parts 30, and the defect part 35 arises in a part, the same effect can be acquired.

In this case, the movement range of the wafer W is regulated as indicated by the dashed-dotted line Q. As shown in FIG. That is, when the wafer W reaches the outer side of the dashed line Q, there is a possibility that the defective portion 50 may be caught and scratches may occur. Also in this modification, the same effect as the above-mentioned polishing pad 20 can be acquired.

In addition, this invention is not limited to the said embodiment as it is, In an implementation step, a component can be modified and actualized in the range which does not deviate from the summary. Moreover, various inventions can be formed by appropriate combination of the some component disclosed by the said embodiment. For example, some components may be deleted from all the components disclosed in the embodiment. Moreover, you may combine suitably the component over other embodiment.

According to the present invention, it is possible to extend the life of the polishing pad and to improve the in-plane uniformity, and to prevent the adhesion of the polishing pad to the polishing pad.

Claims (5)

A polishing pad for polishing a workpiece, The plate-shaped pad body which polished one side and the other side as the support surface, The pad body penetrates from the polishing surface to the support surface, and includes a plurality of hole portions formed by combining a plurality of long holes provided along a plurality of different directions in the surface direction of the polishing surface. pad. The polishing pad according to claim 1, wherein the hole has a long hole disposed radially about a predetermined position. The polishing pad according to claim 1, wherein a communication hole in which the holes adjacent to each other communicate with each other is provided on the support surface side of the pad body. A polishing pad provided on the surface plate, A holding member which is disposed opposite to the polishing pad and holds the polishing object; And a drive mechanism for polishing the to-be-polished surface of the to-be-polished object by performing relative frictional movement of the to-be-polished object held by the said polishing pad and the said holding member, The polishing pad includes a plate-shaped pad body having one surface polished and the other surface supported by the surface plate. The pad body penetrates from the polishing surface to the support surface, and includes a plurality of hole portions formed by combining a plurality of long holes provided along a plurality of different directions in the surface direction of the polishing surface. Device. The said drive mechanism is a relative frictional movement of Claim 4 which the said to-be-grinded object and the said holding member are the periphery of the said grinding | polishing surface, and one part of the said hole part is located in the periphery part, and is spaced apart from the part where the said hole part is exposed. Polishing apparatus, characterized in that.

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