JP2009202291A - Pad conditioner and cmp device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress generation of deviation in wear amount of abrasive grains of a pad conditioner. <P>SOLUTION: This pad conditioner is provided with a conditioner body 110 fixed with a plurality of abrasive grains 112 to the surface, and a pad pressing member 120 located on an outer peripheral side of the abrasive grain 112 located on an outermost periphery to suppress repulsive force of a polishing pad 10 from being applied to the abrasive grain 112 located on the outermost periphery. A distance between the pad pressing member 120 and the abrasive grain 112 located on the outermost periphery is within 1.5 mm, for instance. Thus, the abrasive grain 112 located on the outermost periphery can be suppressed from being worn more than other abrasive grains 112. As a result, generation of deviation in wear amount of the abrasive grains 112 can be suppressed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a pad conditioner and a CMP apparatus for a polishing pad.

  Chemical mechanical polishing (hereinafter referred to as CMP) is a process of polishing a surface to be polished using a polishing pad and slurry, and is used for flattening an interlayer insulating film on a surface of a semiconductor wafer and embedding a metal wiring. It is done. A polishing pad used in CMP is kept in a fuzzy state by being rubbed against a pad conditioner having abrasive grains (hereinafter referred to as “sharpening”). When the pad conditioner deteriorates, the polishing pad becomes insufficiently sharpened, and the CMP polishing rate decreases.

  FIG. 7 shows how the polishing pad 200 is sharpened using the pad conditioner 220. A plurality of abrasive grains 222 are fixed to the surface of the pad conditioner 220. The abrasive grains 222 wear out while sharpening, but the abrasive grains 222 located on the outermost periphery have a faster wear rate than the other abrasive grains 222. This is because the other abrasive grains 222 are in contact with the polishing pad 200 only from the tip direction of the abrasive grains 222, but the abrasive grains 222 located on the outermost periphery are polishing pads from both the tip direction and the outer peripheral surface direction of the abrasive grains 222. This is because of contact. Therefore, in the surface of the pad conditioner 220, the wear amount of the abrasive grains 222 is biased. If this deviation can be suppressed, the life of the pad conditioner 220 will be prolonged.

  As a technique for suppressing the occurrence of unevenness in the wear amount of the abrasive grains of the pad conditioner, there is a technique described in Patent Document 1. In this technique, the pad conditioner has a polishing portion raised in a ring shape on the outer peripheral side. Abrasive grains are fixed to the polishing portion. Curved surfaces are provided on the outer peripheral side and inner peripheral side of the polishing portion. Thereby, the load concentration to the abrasive grains in the outer peripheral portion and the inner peripheral portion is reduced.

  Moreover, there exists a technique of patent document 2 and 3 in the prior art regarding a pad conditioner (it is also called a dresser). The dresser described in Patent Document 2 is obtained by fixing a support member to a concave portion of a dresser body and holding the vertical movement member on the support member. Diamond is fixed to the lower surface of the vertical movement member.

Moreover, the dressing apparatus described in Patent Document 3 includes a dressing plate whose surface is electrodeposited with abrasive grains, and a fixing ring that holds the periphery of the dressing plate.
JP 2006-190899 A JP 2000-753 A JP 2003-136403 A

  However, in the technique described in Patent Document 1 described above, the load concentration on the abrasive grains fixed to the curved surface is reduced, but instead, the load is concentrated on the abrasive particles located near the curved surface. For this reason, it was difficult to suppress the uneven wear amount of the abrasive grains.

According to the present invention, a pad conditioner for sharpening a polishing pad,
A conditioner body having a plurality of abrasive grains fixed on the surface;
A pad pressing member that is located on the outer peripheral side of the abrasive grains located on the outermost periphery and suppresses the repulsive force of the polishing pad from being applied to the abrasive grains located on the outermost periphery;
A pad conditioner is provided.

Moreover, according to the present invention, a pad conditioner for sharpening a polishing pad,
A conditioner body having a plurality of abrasive grains fixed on the surface;
A pad pressing member that protrudes from the surface of the conditioner body, and is positioned on the outer peripheral side of the abrasive grains positioned on the outermost periphery;
With
A pad conditioner is provided in which the distance from the pad pressing member to the abrasive grains located on the outermost periphery is within 1.5 mm.

According to the present invention, any one of the pad conditioners described above,
A polishing pad;
A CMP apparatus comprising:

  According to the present invention, it is possible to suppress the repulsive force of the polishing pad from being applied to the abrasive grains located on the outermost periphery, and thus it is possible to suppress the abrasive grains located on the outermost periphery from being worn away than the other abrasive grains. For this reason, it can suppress that a bias | deviation arises in the abrasion loss of an abrasive grain.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.
(First embodiment)

  FIG. 1 is a diagram illustrating a configuration of a CMP apparatus according to the first embodiment. The CMP apparatus includes a polishing pad 10 that performs CMP of a surface to be polished and a pad conditioner 100 that sharpens the polishing pad 10. The pad conditioner 100 is disk-shaped and rotates while pressing against the polishing pad 10 to sharpen the polishing pad 10. The polishing pad 10 is made of, for example, foamed polyurethane and a cushion layer.

  The pad conditioner 100 includes a conditioner main body 110 and a pad pressing member 120. The conditioner body 110 has a plurality of abrasive grains 112 fixed to its surface. The abrasive grains 112 are, for example, diamond. The pad pressing member 120 suppresses the repulsive force of the polishing pad 10 from being applied to the abrasive grains 112 located on the outermost periphery. For example, the pad pressing member 120 protrudes from the surface of the conditioner body 110 and is positioned on the outer peripheral side with respect to the abrasive grains 112 positioned on the outermost periphery. The distance from the pad pressing member 120 to the abrasive grains 112 located on the outermost periphery is within 1.5 mm, for example.

  As described above, the pad pressing member 120 suppresses the repulsive force of the polishing pad 10 from being applied to the abrasive grains 112 located on the outermost periphery. Therefore, it can suppress that the abrasive grain 112 located in the outermost periphery wears out from the other abrasive grain 112. For this reason, it can suppress that the abrasion amount of the abrasive grain 112 produces unevenness. Hereinafter, the pad conditioner 100 will be described in detail.

  FIG. 2 is a plan view of the pad conditioner 100. The planar shape of the conditioner body 110 is circular, and the planar shape of the pad pressing member 120 is a ring shape. The pad pressing member 120 is attached to the outer peripheral portion of the surface of the conditioner body 110. The pad pressing member 120 is provided on the entire circumference of the conditioner body 110 and surrounds the region of the conditioner body 110 where the abrasive grains 112 are fixed. The side surface on the outer peripheral side of the pad pressing member 120 is substantially flush with the side surface of the conditioner body 110. The pad pressing member 120 is made of, for example, resin or metal. Since the pad pressing member 120 does not contribute to sharpening, it is preferable that the pad pressing member 120 has a small width.

  FIG. 3 is a cross-sectional view of the pad conditioner 100 when the polishing pad 10 is sharpened. The height of the pad pressing member 120 is preferably substantially equal to or slightly lower than the distance from the surface of the conditioner body 110 to the tip of the abrasive grains 112.

  When the pad conditioner 100 presses against the polishing pad 10, the abrasive grains 112 and the pad pressing member 120 of the pad conditioner 100 receive a repulsive force from the polishing pad 10. In this embodiment, the pad pressing member 120 is provided outside the abrasive grains 112 located on the outermost periphery. The distance D from the abrasive grains 112 located on the outermost periphery to the pad pressing member 120 is 1.5 mm or less, preferably 1 mm or less. In this way, the pad pressing member 120 suppresses the polishing pad 10 from being pressed against the side surface of the abrasive grain 112 located on the outermost periphery. As a result, the abrasive grains 112 located on the outermost periphery are pressed against the polishing pad 10 substantially in the same manner as the other abrasive grains 112. Therefore, it can suppress that the abrasive grain 112 located in the outermost periphery wears out from the other abrasive grain 112. As a result, in the surface of the conditioner body 110, it is possible to suppress the occurrence of unevenness in the amount of wear of the abrasive grains 112. This effect can be obtained regardless of the elasticity of the polishing pad 10. For this reason, the pad conditioner 100 according to the present embodiment is highly versatile.

  FIG. 4A is a graph showing the relationship between the degree of wear of the abrasive grains 112 located on the outermost circumference and the distance D, and FIG. 4B shows the definition of the degree of wear in FIG. As shown in FIG. 4B, the degree of wear in FIG. 4A is the length L of the long side of the portion of the abrasive grains 112 that has become flat due to wear.

As shown to Fig.4 (a), when the distance D is 1.5 mm or less, the abrasion degree is low compared with the case where the distance D is 2.0 mm or more. This is because when the distance D is 1.5 mm or less, the pad pressing member 120 suppresses the polishing pad 10 from being pressed against the side surface of the abrasive grains 112 located on the outermost periphery. This effect is particularly remarkable when the distance D is 1.0 mm or less. When the distance D is 2.0 mm or more, the polishing pad 10 enters the space between the abrasive grains 112 located on the outermost periphery and the pad pressing member 120, so that polishing is performed on the side surfaces of the abrasive grains 112 located on the outermost circumference. The repulsive force of the pad is applied, and the degree of wear of the abrasive grains 112 located on the outermost periphery is increased.
(Second Embodiment)

  The CMP apparatus according to the present embodiment is the same as the structure of the CMP apparatus according to the first embodiment except for the shape of the pad pressing member 120 of the pad conditioner 100. Hereinafter, the description is omitted except for the shape of the pad pressing member 120.

  Fig.5 (a) is a top view of the pad conditioner 100 concerning this embodiment, FIG.5 (b) is AA 'sectional drawing of Fig.5 (a). The pad pressing member 120 according to the present embodiment is divided into a plurality of arc-shaped members, and there are gaps 122 between the individual members. The gap 122 connects the inner side and the outer side of the pad pressing member 120. In the example shown in the figure, the gap 122 extends along a straight line passing through the center of the pad pressing member 120.

  By providing the gap 122, it is possible to efficiently introduce the polishing liquid from the outside to the inside of the pad pressing member 120, and it is also possible to efficiently remove the pad scraps generated inside the pad pressing member 120. It can be discharged out of 120.

For this reason, according to the present embodiment, the same effects as those of the first embodiment can be obtained, and the sharpening efficiency of the polishing pad 10 can be increased. In addition, defects are reduced.
(Third embodiment)

  The CMP apparatus according to the present embodiment is the same as the configuration of the CMP apparatus according to the second embodiment except for the shape of the gap 122 of the pad pressing member 120. Hereinafter, the description is omitted except for the shape of the gap of the pad pressing member 120.

  FIG. 6 is a plan view of the pad conditioner 100 according to the present embodiment. In this embodiment, the pad pressing member 120 includes two types of spiral gaps 122a and 122b. The gaps 122a and 122b have spiral directions opposite to each other. In this way, one of the gaps 122 a and 122 b efficiently introduces the abrasive liquid from the outside to the inside of the pad pressing member 120. Further, the other of the gaps 122 a and 122 b efficiently discharges the pad scraps generated inside the pad pressing member 120 to the outside of the pad pressing member 120.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable. For example, in the first embodiment, a groove connecting the inner side and the outer side may be formed on the surface of the pad pressing member 120. The shape of the groove may be the same as the gap 122 in the second embodiment, or may be the same as the gaps 122a and 122b in the second embodiment. Even if it does in this way, the effect similar to 2nd or 3rd embodiment can be acquired.

  In each of the above-described embodiments, the pad pressing member 120 is attached to the surface of the conditioner main body 110. However, the pad pressing member 120 may be provided so as to surround the conditioner main body 110. Even in this case, the repulsive force of the polishing pad 10 is applied to the abrasive grains 112 located on the outermost periphery by setting the distance D between the pad pressing member 120 and the abrasive grains 112 located on the outermost circumference to, for example, 1.5 mm or less. Can be suppressed.

It is a figure which shows the structure of the CMP apparatus concerning 1st Embodiment. 2 is a plan view of the pad conditioner 100. FIG. 2 is a cross-sectional view of the pad conditioner 100 when the polishing pad 10 is sharpened. FIG. (A) is a graph which shows the relationship between the abrasion degree of the abrasive grain 112 located in the outermost periphery, and the distance D, (b) is a figure which shows the definition of the abrasion degree in Fig.4 (a). (A) is a top view of the pad conditioner 100 concerning 2nd Embodiment, (b) is AA 'sectional drawing of (a). It is a top view of pad conditioner 100 concerning a 3rd embodiment. It is a figure which shows a mode that the polishing pad 200 is sharpened using the conventional pad conditioner 220. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Polishing pad 100 Pad conditioner 110 Conditioner main body 112 Abrasive grain 120 Pad pressing member 122 Crevice 122a, 122b Gap

Claims (5)

A pad conditioner for sharpening a polishing pad,
A conditioner body having a plurality of abrasive grains fixed on the surface;
A pad pressing member that is located on the outer peripheral side of the abrasive grains located on the outermost periphery and suppresses the repulsive force of the polishing pad from being applied to the abrasive grains located on the outermost periphery;
Pad conditioner with A pad conditioner for sharpening a polishing pad,
A conditioner body having a plurality of abrasive grains fixed on the surface;
A pad pressing member that protrudes from the surface of the conditioner body, and is positioned on the outer peripheral side of the abrasive grains positioned on the outermost periphery;
With
A pad conditioner in which a distance from the pad pressing member to the abrasive grains located on the outermost periphery is within 1.5 mm. The pad conditioner according to claim 1 or 2,
The pad pressing member is a pad conditioner that surrounds a region of the surface of the conditioner body where the abrasive grains are fixed. The pad conditioner according to claim 1 or 2,
The pad pressing member is a pad conditioner having a groove or a gap connecting the inner side and the outer side of the pad pressing member. A pad conditioner according to any one of claims 1 to 4,
A polishing pad;
A CMP apparatus comprising:

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