US20150047266A1

US20150047266A1 - Methods for manufacturing polishing pad and polishing apparatus

Info

Publication number: US20150047266A1
Application number: US14/455,074
Authority: US
Inventors: Chung-Chih Feng; I-Peng Yao; Yung-Chang Hung; Wen-Chieh Wu
Original assignee: San Fang Chemical Industry Co Ltd
Current assignee: San Fang Chemical Industry Co Ltd
Priority date: 2013-08-16
Filing date: 2014-08-08
Publication date: 2015-02-19
Also published as: TW201507814A

Abstract

The present invention relates to a method for manufacturing a polishing pad. The method of the invention includes the steps of (a) providing a releasing carrier; (b) providing a foaming resin composition; (c) coating the foaming resin composition of the step (b) on the carrier of the step (a); and (d) curing the foaming resin composition of the step (c). The invention also provides a process for manufacturing a polishing apparatus.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a method for manufacturing a polishing pad and a process for manufacturing a polishing apparatus.
2. Description of the Related Art
Polishing generally refers to a wear control for a preliminary coarse surface in a process of chemical mechanical polishing (CMP), which makes the slurry containing fine particles evenly dispersed on the upper surface of a polishing pad, and at the same time places a substrate against the polishing pad and then rubs the substrate repeatedly with a regular motion. The substrate may be objects such as a semiconductor, a storage medium substrate, an integrated circuit, an LCD flat-panel glass, an optical glass and a photoelectric panel. During the polishing process, a polishing pad must be used for polishing the substrate, and the quality of the polishing pad directly influences the polishing effect of the substrate.
FIG. 1 shows a schematic view of a polishing apparatus with a conventional polishing pad. The polishing apparatus 1 includes a lower base plate 11, a mounting sheet 12, a substrate 13, an upper base plate 14, a polishing pad 15 and slurry 16. The lower base plate 11 is positioned opposite to the upper base plate 14. The mounting sheet 12 is adhered to the lower base plate 11 through an adhesive layer (not shown) and is used for carrying and mounting the substrate 13. The polishing pad 15 is mounted on the upper base plate 14, and faces to the lower base plate 11 for polishing the substrate 13.
The operation mode of the polishing apparatus 1 is as follows. First, the substrate 13 is mounted on the mounting sheet 12, and then both the upper and lower base plates 14 and 11 are rotated and the lower base plate 11 is simultaneously moved downward, such that the polishing pad 15 contacts the surface of the substrate 13, and a polishing operation for the substrate 13 may be performed by continuously supplementing the slurry 16 and using the effect of the polishing pad 15.
A conventional method for manufacturing the polishing pad is as disclosed by U.S. Patent No. 2006/0035573, which comprises foaming a polymer resin solution by infiltrating air, adding a bridging agent, and then filling the solution into an appropriate mold. After forming a columnar elastomer by high temperature or chemical crosslinking curing interaction, and removing the mold, then, the polishing pad is formed by cooling and cutting into slices. In the conventional method for manufacturing the polishing pad, when foaming the polymer resin solution by infiltrating air, the air easily floats due to its low density. As a reason, the air is not easy to uniformly distribute as filling the solution into the mold. The air content of an upper part of the columnar elastomer is too much, and the air content of a lower part of the columnar elastomer is too less, so only a middle part of the columnar elastomer can be used. Furthermore, if an interior region of the columnar elastomer exists a defect such as unevenly foaming; several polishing pads positioned in the interior region are all affected. Moreover, it is difficult to control the process of mold filling, especially when the filling size rises. For example, the prolonged filling time may affect the curing of the resin and thereby affect the post processing. When applying the conventional polishing pad in the chemically mechanical polishing method, the flatness of the substrate is poor due to the poor quality of the polishing pad, and the rise of the uneven degree of the substrate causes polishing particles in the slurry be remained on a surface of the substrate and scrap the surface of the substrate to be polished. For example, in a wafer manufacture, a scraping of a wafer surface affects stability and affects a post manufactures of lithography, development, and etching. After micro integrated circuit multiple overlaid, the stability is also reduced which increases the defective rate, and further increases the cost.

SUMMARY OF THE INVENTION

The invention adopts a coating method for manufacturing a polishing pad, and a polishing pad of uniformly foaming is obtained thereby, and thickness of the polishing pad is controlled easily. A post processing, storage and transportation are improved also and the polishing pad can be applied in a continuously manufacture.
The invention provides a method for manufacturing a polishing pad comprising:

- (a) providing a carrier, wherein the carrier is a releasing material;
- (b) providing a foaming resin composition;
- (c) coating the foaming resin composition of the step (b) on the carrier of the step (a); and
- (d) curing the foaming resin composition of the step (c).

The invention also provides a process for manufacturing a polishing apparatus, wherein the polishing apparatus comprising:

- a base plate;
- a substrate;
- a polishing pad, which is adhered on the base plate for polishing the substrate; and
- a slurry, which is contacting with the substrate for polishing;
- wherein the process comprises the aforementioned method for manufacturing the polishing pad.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a schematic view of a polishing apparatus with a conventional polishing pad;

FIG. 2 shows a schematic view of a polishing apparatus with a polishing pad according to the invention;

FIG. 3 shows a view under the scanning electron microscope of the polishing pad according to the invention; and

FIG. 4 shows a view under the scanning electron microscope of the conventional polishing pad.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides a method for manufacturing a polishing pad comprising:

The term “carrier” as used herein refers to an element which allows the foaming resin composition formed thereon and the foaming resin composition can be easily removed after curing. Preferably, the carrier is a sheet; in another aspect, the carrier is a releasing material. The term “releasing material” as used herein refers to a material which does not react with the foaming resin composition in the polishing pad manufacturing process and the foaming resin composition can be easily removed after the curing. Preferably, the releasing material is “a film with low permeability.” The term “film with low permeability” as used herein refers to a film or thin film that substantially prevents the foaming resin composition on an upper surface of the film with low permeability according to the invention from permeating to a lower surface of the film with low permeability. In one preferred embodiment of the invention, the film with low permeability can be formed on a base material, for example, a paper. Preferably, the carrier comprises a polyethylene glycol terephthalate film, a polypropylene film, a polycarbonate film, a polyethylene film, a polyethylene terephthalate film, a releasing paper or a releasing fabric. Additionally, the preferable polypropylene is oriented polypropylene.
Preferably, the carrier is continuously provided, for example, is a rolling releasing material. The rolling releasing material can be used by roll to roll. Comparing to the conventional manufacture relative to molding or casting a single polishing pad, the method according to the invention improves batch uniformity.
In one embodiment of the invention, the foaming resin composition comprises a resin, a foaming agent, and a bridging agent.
The resin according to the invention is, preferably, an elastomer. As used herein, the term “elastomer,” also known as “elastic polymer,” refers to a type of polymer that exhibits rubber-like qualities. When polishing, the elastomer serves as a good buffer to avoid scraping a surface of the substrate to be polished. As used herein, the term “foaming resin” refers to a material containing a thermoplastic resin and a thermodecomposing foaming agent. Preferably, the resin comprises at least one selected from the group consisting of polyurethane, polyolefin, polycarbonate, polyvinyl alcohol, nylon, elastic rubber, polystyrene, poly aromatic molecules, fluorine-containing polymer, polyimide, crosslinked polyurethane, crosslinked polyolefin, polyether, polyester, polyacrylate, elastic polyethylene, polytetrafluoroethene, poly (ethylene terephthalate), poly aromatic amide, polyarylalkene, polymethyl methacrylate, a copolymer thereof, a block copolymer thereof, a mixture thereof, and a blend thereof.
The term “foaming agent” as used herein refers to a resin foaming agent or method according the invention. A manner of foaming the resin according the invention can be chemically foaming or physically foaming, wherein the chemically foaming manner uses an agent to carry on a chemical reaction to yield gas for being evenly distributed in the resin composition. Besides, the physically foaming manner comprises infiltrating gas into the resin composition for being evenly distributed in the resin composition by stiffing.
The term “crosslinked agent” as used herein refers to an agent that may generate a crosslinked reaction with the resin according to the invention and cure the resin under an appropriate condition. The kind of the crosslinked agent is determined according to the kind of the resin.
In one preferred embodiment of the invention, the foaming resin composition further comprises a polishing particle. The polishing particle can coordinate with the slurry for polishing. The polishing particle is evenly distributed in the foaming resin composition; wherein, it can exist in the resin of the polishing pad, and it can also exist in foaming pores of the polishing pad. Preferably, the polishing particle comprises cerium dioxide, silicon dioxide, aluminum oxide, yttrium oxide, or ferric oxide. Additionally, the particle diameter of the polishing particle is from 0.01 μm to 10 μm.
In one embodiment of the invention, the step (c) comprises blade coating, printing wheel coating, roll extrusion coating or spraying. The manner of coating may be chosen by artisans skilled in this field. Besides, the preferred coating is continuously coating.
The method according the invention, the step (d) is curing the foaming resin composition of the step (c). The manner of curing may be chosen by artisans skilled in this field according to the kind of the curing resin and bridging agent needed. In one preferred embodiment of the invention, the curing step is curing the foaming resin composition which has been dried at a high temperature of 60° C. to 130° C.
In one preferred embodiment of the invention, the method further comprises a surface finishing step, which is finishing a surface of the cured resin composition in the step (d). The embodiment of finishing is polishing or shaving a part of the surface. The manner of polishing or shaving the part of the surface may be chosen by artisans skilled in this field, for example, using sandpaper to polish or a knife to shave; wherein the manners of the polishing or shaving are well known to artisans skilled in this field.
In one preferred embodiment of the invention, the method further comprises a step of groove forming, which is forming at least one groove on the surface of the cured resin composition in the step (d). The manner of processing of forming the groove on the surface of the cured resin composition may be chosen by artisans skilled in this field according to the specification, for example, using laser processing. The groove helps the slurry flow in the polishing, and preferably, the ratio of the groove range and the groove wide is from about 1 to about 0.05.
In one preferred embodiment of the invention, the method according to the invention is to collocate with a continuously provided carrier. The steps of the invention are coordinated as a production line with the using of a roller, and providing, coating, curing, finishing, and groove forming, can be performed continuously and the manufacture is more easily.
In one preferred embodiment of the invention, the method further comprises a step (e) of removing the carrier. Preferably, the step of removing the carrier is removing the polishing pad from manufacturing equipment after the manufacture method is completed. On the other hand, the step of removing the carrier is removing the carrier from the polishing pad when polishing. The specific manner of the removing depends on the carrier, for example, the manner is peeling.
In one embodiment of the invention, the method further comprises a step of applying an adhesive on the surface of the cured resin composition which makes the polishing pad fix on the base plate. The adhesive may be chosen by artisans skilled in this field according to the specification.
In one embodiment of the invention, the method further comprises a step of applying an adhesive on a surface of the carrier which makes the polishing pad fix on the base plate. The adhesive may be chosen by artisans skilled in this field according to the specification.
In one preferred embodiment of the invention, the adhesive is a pressure sensitive adhesion or polyurethane. The term “pressure sensitive adhesion” as used herein refers to a thin carrier film of and an adhesive agent on the upper and lower side of the thin carrier film. Preferably, the thin carrier film is selected from the group consisting of polyethylene terephthalate, polypropylene and polyethylene.
Because the invention adopts a coating method for manufacturing the polishing pad, the step of mold filing is avoided, and a polishing pad of uniformly foaming is obtained. Furthermore, it is easy to control the thickness of coating. It benefits the post processing, storage and transportation. It can be applied in the continuously manufacture and reduce the manufacturing costs because of eliminating the steps of process.
The invention also provides a process for manufacturing a polishing apparatus, wherein the polishing apparatus comprising:

- a base plate;
- a substrate;
- a polishing pad, which is adhered on the base plate for polishing the substrate; and
- a slurry, which is contacting with the substrate for polishing;
- wherein the process comprises the aforementioned method for manufacturing the polishing pad.
- Preferably, the polishing apparatus further comprises:
- a lower base plate positioned opposite to the base plate; and
- a mounting sheet adhered to the lower base plate for mounting and securing the substrate.

FIG. 2 shows a schematic view of a polishing apparatus with a polishing pad according to the invention. The polishing apparatus 2 includes a lower base plate 21, a mounting sheet 22, a substrate 23, an upper base plate 24, a polishing pad 25 and slurry 26. The lower base plate 21 is positioned opposite to the upper base plate 24. The mounting sheet 22 is adhered to the lower base plate 21 through an adhesive layer (not shown) and is used for carrying and mounting the substrate 23. The polishing pad 25 is mounted on the upper base plate 24 and faces to lower base plate 21 for polishing the substrate 23.
The operation mode of the polishing apparatus 2 is as follows. First, the substrate 23 is mounted on the mounting sheet 22, and then both the upper and lower base plates 24 and 21 are rotated and the upper base plate 24 is simultaneously moved downward, such that the polishing pad 25 contacts the surface of the substrate 23, and a polishing operation for the substrate 23 may be performed by continuously supplementing the slurry 26 and using the effect of the polishing pad 25.
The following Examples are given for the purpose of illustration only and are not intended to limit the scope of the present invention.

Example

A resin composition is stirred uniformly and air is infiltrated into the resin composition at a rate of 1000 rpm to 4000 rpm. Then, the resin composition is coated on a releasing paper with a scraper. The resin composition is cured at 110° C. for 1 minute, and then dried at 80° C. for 30 seconds in an oven, and the surface is shaved. FIG. 3 shows a view under the scanning electron microscope, and the figure shows that the foam is evenly distributed.

Comparative Example

A resin composition is stirred uniformly and air is infiltrated into the resin composition at a rate of 1000 rpm to 4000 rpm, then the resin composition is filled into a mold. The resin composition is heated at 60° C. for 3 minutes and removed from the mold. The resin composition is further heated at 110° C. for 16 seconds, and cut into slices. FIG. 4 shows a view under the scanning electron microscope. Because the resin composition is foamed by infiltrating air, the air easily floats due to its low density. The foam is difficult to be uniformly distributed as filling the composition into the mold. The air content of an upper part of the resin composition is too much, and the air content of a lower part of the resin composition is too less, so only a middle part of the resin composition can be used.
The physically evaluation results of the aforementioned polishing pads are as shown in the following Table 1, which shows that the polishing pads obtained in Examples have the lower compression rate and the higher hardness, and the polishing pads obtained in Examples are better than the polishing pads obtained in Comparative Examples. Furthermore, the amount of transformation is also relatively lower.

TABLE 1

			Hard-		Com-
	Coating	Film	ness	Com-	pression	Den-
	interval	thickness	(shore	pression	recover	sity
	(mm)	(mm)	D)	rate	rate	(g/cm³)

Example	0.75	0.50-0.55	16-18	1.58%	89.77%	0.75
Comparative	2.50	2.90-3.10	14-16	5.16%	73.46%	0.63
Example

While embodiments of the present invention have been illustrated and described, various modifications and improvements can be made by persons skilled in the art. The embodiments of the present invention are therefore described in an illustrative but not restrictive sense. It is intended that the present invention is not limited to the particular forms as illustrated, and that all the modifications not departing from the spirit and scope of the present invention are within the scope as defined in the appended claims.

Claims

What is claimed is:

1. A method for manufacturing a polishing pad comprising:

(a) providing a carrier, wherein the carrier is a releasing material;

(b) providing a foaming resin composition;

(c) coating the foaming resin composition of the step (b) on the carrier of the step (a); and

(d) curing the foaming resin composition of the step (c).

2. The method according to claim 1, wherein the carrier comprises a polyethylene glycol terephthalate film, a polypropylene film, a polycarbonate film, a polyethylene film, a polyethylene terephthalate film, a releasing paper or a releasing fabric.

3. The method according to claim 1, wherein the carrier is continuously provided.

4. The method according to claim 1, wherein the foaming resin composition comprises a resin, a foaming agent, and a bridging agent.

5. The method according to claim 4, wherein the resin comprises at least one selected from the group consisting of polyurethane, polyolefin, polycarbonate, polyvinyl alcohol, nylon, elastic rubber, polystyrene, poly aromatic molecules, fluorine-containing polymer, polyimide, crosslinked polyurethane, crosslinked polyolefin, polyether, polyester, polyacrylate, elastic polyethylene, polytetrafluoroethene, poly (ethylene terephthalate), poly aromatic amide, polyarylalkene, polymethyl methacrylate, a copolymer thereof, a block copolymer thereof, a mixture thereof, and a blend thereof.

6. The method according to claim 1, wherein the foaming resin composition further comprises a polishing particle.

7. The method according to claim 1, wherein the step (c) comprises blade coating, printing wheel coating, roll extrusion coating or spraying.

8. The method according to claim 1, further comprising a surface finishing step, which is finishing a surface of the cured resin composition in the step (d).

9. The method according to claim 1, further comprising a groove forming step, which is forming at least one groove on a surface of the cured resin composition in the step (d).

10. The method according to claim 1, further comprising a step (e) of removing the carrier.

11. The method according to claim 1, further comprising a step of applying an adhesive on a surface of the cured resin composition.

12. The method according to claim 1, further comprising a step of applying an adhesive on a surface of the carrier.

13. A process for manufacturing a polishing apparatus, wherein the polishing apparatus comprising:

a base plate;

a substrate;

a polishing pad, which is adhered on the base plate for polishing the substrate; and

a slurry, which is contacting with the substrate for polishing;

wherein the process comprises the method for manufacturing the polishing pad according to claim 1.

14. The process according to claim 13, wherein the carrier comprises a polyethylene glycol terephthalate film, a polypropylene film, a polycarbonate film, a polyethylene film, a polyethylene terephthalate film, a releasing paper or a releasing fabric.

15. The process according to claim 13, wherein the carrier is continuously provided.

16. The process according to claim 13, wherein the foaming resin composition comprises a resin, a foaming agent, and a bridging agent.

17. The process according to claim 16, wherein the resin comprises at least one selected from the group consisting of polyurethane, polyolefin, polycarbonate, polyvinyl alcohol, nylon, elastic rubber, polystyrene, poly aromatic molecules, fluorine-containing polymer, polyimide, crosslinked polyurethane, crosslinked polyolefin, polyether, polyester, polyacrylate, elastic polyethylene, polytetrafluoroethene, poly (ethylene terephthalate), poly aromatic amide, polyarylalkene, polymethyl methacrylate, a copolymer thereof, a block copolymer thereof, a mixture thereof, and a blend thereof.

18. The process according to claim 13, wherein the foaming resin composition further comprises a polishing particle.

19. The process according to claim 13, wherein the step (c) comprises blade coating, printing wheel coating, roll extrusion coating or spraying.

20. The process according to claim 13, further comprising a surface finishing step, which is finishing a surface of the cured resin composition in the step (d).

21. The process according to claim 13, further comprising a groove forming step, which is forming at least one groove on a surface of the cured resin composition in the step (d).

22. The process according to claim 13, further comprising a step (e) of removing the carrier.

23. The process according to claim 13, further comprising a step of applying an adhesive on a surface of the cured resin composition.

24. The process according to claim 13, further comprising a step of applying an adhesive on a surface of the carrier.