JP4103106B2 - Polishing cloth - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polishing cloth (polishing pad) used for manufacturing semiconductors.
[0002]
[Prior art]
Conventionally, a polishing cloth has been used for performing a planarization process of an object to be polished (wafer or the like) by a chemical mechanical polishing process (CMP process).
In order to make it easier for the slurry newly supplied to the polishing work surface between the polishing object to enter the surface of the polishing cloth, concentric circles (see FIGS. 7 and 8) and lattice shapes (see FIGS. 9 and 9). 10) and a hole 11 (see FIGS. 11 and 12) is provided. In the figure, C indicates the center of the polishing pad. In addition, there is an advantage that during the rotary polishing, the grooves 11 can assist the dispersion of the slurry to prevent excessive adsorption of the object to be polished and improve the polishing efficiency.
[0003]
However, the dispersion of the slurry is not uniform and a high frictional force may be generated locally. In severe cases, the polishing device vibrates during rotary polishing, and the object to be polished pops out due to centrifugal force, causing damage. There was a problem that there was.
[0004]
[Problems to be solved by the invention]
Therefore, the present invention intends to provide an abrasive cloth that can disperse the slurry more uniformly than in the prior art.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the present invention takes the following technical means.
(1) A polishing cloth according to the present invention is a polishing cloth having a plurality of groove portions in which a supplied slurry is dispersed concentrically at a constant interval and a constant depth, and a plurality of grooves having a common groove width. It has a plurality of groove regions composed of groove portions, and the groove width region on the center side of each groove portion region has a narrow groove width, and the groove portion region on the outer peripheral side is smaller than the groove region on the central side. The groove width is set so as to gradually widen for each of a plurality of grooves in each region.
(2) A polishing cloth having a plurality of groove portions in which the supplied slurry is dispersed concentrically at a constant interval and with a predetermined depth, and the groove portion on the center side of each groove portion has a narrow groove width and an outer periphery. The groove portion on the side may be set so that the groove width gradually expands for each groove as compared with the groove portion on the center side.
[0006]
That is, conventionally, the groove portion is almost constant between the center side and the outer peripheral side of the polishing cloth, and therefore, during polishing, the slurry is dispersed in the center side where the transition speed in rotation driving is relatively slow and the outer peripheral side where the transition speed is relatively fast. Although there was variation (the slurry on the outer peripheral side tends to be insufficient compared to the center side), this abrasive cloth is relatively fast compared to the center side where the transition speed in rotation drive is relatively slow. Since the outer peripheral groove region is set large, a large amount of slurry can be supplied to the outer peripheral groove region where the transition speed is relatively fast and the slurry is easily discharged .
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
(Embodiment 1)
The polishing cloth of this embodiment is made of urethane resin, and has a groove portion 1 in which the supplied slurry is dispersed, as shown in FIGS. 1 and 2, and has an outer peripheral side as compared with the groove portion 1 on the center C side. The area of the groove 1 is set large.
[0008]
The groove portion 1 is formed concentrically, and the region of the groove portion 1 on the outer peripheral side is set so that the groove width gradually increases as compared with the groove portion 1 on the center C side. That is, the region of the groove 1 includes three first areas X on the side of the center C having the narrowest width, three second areas Y on the next side, and three third areas on the outermost side on the widest side. It was formed to have three regions of Z.
[0009]
Next, the usage state of the polishing cloth of this embodiment will be described.
[0010]
Conventionally, the width of the groove portion is substantially constant between the center side and the outer peripheral side of the polishing cloth, and therefore, during polishing, the slurry is dispersed in the center side where the transition speed in rotation driving is relatively slow and the outer peripheral side where the transition speed is relatively fast. Although the variation occurred, this polishing cloth has a relatively fast transition speed in the rotational drive, and the relatively fast outer peripheral groove region 1 is set larger than the center C side. A larger amount of slurry can be supplied to the region of the groove 1 on the outer peripheral side where the slurry is easily discharged relatively quickly, and there is an advantage that the slurry can be dispersed more uniformly than in the past.
[0011]
Further, excessive friction between the polishing cloth and the wafer due to non-uniform dispersion of the slurry is reduced, and there is an advantage that unnecessary vibration of the apparatus can be prevented and damage to the wafer can be prevented.
(Embodiment 2)
Next, the second embodiment will be described focusing on the differences from the first embodiment.
[0012]
As shown in FIGS. 3 and 4, the polishing cloth of this embodiment also has a concentric groove portion 1, and the region of the groove portion 1 on the outer peripheral side in comparison with the groove portion 1 on the center C side gradually increases its groove width. Was set to spread. That is, the groove width is formed so as to gradually expand from the groove portion 1 on the center C side to the region of the groove portion 1 on the outer peripheral side, such as 1, 1.1, 1.2, 1.3, 1.4,. did.
(Embodiment 3)
Next, the second embodiment will be described focusing on the differences from the above embodiment.
[0013]
As shown in FIG. 5 and FIG. 6, the polishing cloth of this embodiment has a hole-shaped groove portion 1, and the hole diameter of the groove portion 1 is larger in the region of the outer peripheral groove portion 1 than the groove portion 1 on the center C side. Was set as follows.
[0014]
【The invention's effect】
The present invention is configured as described above and has the following effects.
[0015]
To provide a polishing cloth that can disperse slurry more uniformly than in the prior art because a larger amount of slurry can be supplied to the region of the groove on the outer peripheral side where the transition speed is relatively fast and the slurry is easily discharged. Can do.
[Brief description of the drawings]
FIG. 1 is a plan view for explaining Embodiment 1 of an abrasive cloth of the present invention.
2 is an enlarged cutaway perspective view of a main part of the polishing cloth of FIG. 1. FIG.
FIG. 3 is a plan view for explaining a polishing cloth according to a second embodiment of the present invention.
4 is an enlarged fragmentary perspective view of the polishing cloth of FIG. 3;
FIG. 5 is a plan view for explaining a polishing cloth according to a third embodiment of the present invention.
6 is an enlarged cutaway perspective view of a main part of the polishing cloth of FIG. 5;
FIG. 7 is a plan view illustrating a conventional polishing cloth.
8 is an enlarged cutaway perspective view of a main part of the polishing pad of FIG.
FIG. 9 is a plan view illustrating another example of a conventional polishing cloth.
10 is an enlarged cutaway perspective view of a main part of the polishing pad of FIG. 9;
FIG. 11 is a plan view for explaining still another example of a conventional polishing cloth.
12 is an enlarged cutaway perspective view of a main part of the polishing pad of FIG.
[Explanation of symbols]
1 Center of groove C

Claims (2)

A polishing cloth having a plurality of groove portions in which the supplied slurry is dispersed concentrically with a constant interval and a predetermined depth , and having a plurality of groove regions composed of a plurality of groove portions having a common groove width. Of the groove regions, the groove region on the center side has a narrow groove width, and the groove region on the outer peripheral side has a groove width that is larger than the groove region on the center side for each of the plurality of grooves in each region. A polishing cloth characterized by being set to gradually spread. A polishing cloth having a plurality of groove portions in which the supplied slurry is dispersed concentrically with a constant interval and a constant depth, and the groove portion on the center side of each groove portion has a narrow groove width, and the groove portion on the outer peripheral side. Is a polishing cloth characterized in that the groove width is set so as to expand step by step as compared to the groove on the center side.

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