US20120302142A1 - Polishing pad and method of producing the same - Google Patents
Polishing pad and method of producing the same Download PDFInfo
- Publication number
- US20120302142A1 US20120302142A1 US13/555,868 US201213555868A US2012302142A1 US 20120302142 A1 US20120302142 A1 US 20120302142A1 US 201213555868 A US201213555868 A US 201213555868A US 2012302142 A1 US2012302142 A1 US 2012302142A1
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- United States
- Prior art keywords
- polishing pad
- polishing
- base material
- bundles
- long fibers
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 238000005498 polishing Methods 0.000 title claims abstract description 80
- 238000000034 method Methods 0.000 title claims abstract description 32
- 239000000835 fiber Substances 0.000 claims abstract description 105
- 239000000463 material Substances 0.000 claims abstract description 47
- 229920001971 elastomer Polymers 0.000 claims abstract description 44
- 239000000806 elastomer Substances 0.000 claims abstract description 44
- 239000000758 substrate Substances 0.000 claims abstract description 31
- 239000002002 slurry Substances 0.000 claims description 15
- 238000007517 polishing process Methods 0.000 claims description 9
- 238000001035 drying Methods 0.000 claims description 8
- 238000005406 washing Methods 0.000 claims description 7
- 239000002131 composite material Substances 0.000 claims description 6
- 239000004952 Polyamide Substances 0.000 claims description 4
- 229920002647 polyamide Polymers 0.000 claims description 4
- -1 polyethylene terephthalate Polymers 0.000 claims description 4
- 239000011347 resin Substances 0.000 claims description 4
- 229920005989 resin Polymers 0.000 claims description 4
- 239000006260 foam Substances 0.000 claims description 3
- 229920003229 poly(methyl methacrylate) Polymers 0.000 claims description 3
- 229920000728 polyester Polymers 0.000 claims description 3
- 229920000139 polyethylene terephthalate Polymers 0.000 claims description 3
- 239000005020 polyethylene terephthalate Substances 0.000 claims description 3
- 239000004926 polymethyl methacrylate Substances 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 2
- 229920002239 polyacrylonitrile Polymers 0.000 claims description 2
- MHSKRLJMQQNJNC-UHFFFAOYSA-N terephthalamide Chemical compound NC(=O)C1=CC=C(C(N)=O)C=C1 MHSKRLJMQQNJNC-UHFFFAOYSA-N 0.000 claims description 2
- 239000004745 nonwoven fabric Substances 0.000 description 23
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 15
- 239000004744 fabric Substances 0.000 description 9
- 230000008569 process Effects 0.000 description 8
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 6
- 230000006835 compression Effects 0.000 description 6
- 238000007906 compression Methods 0.000 description 6
- 235000012431 wafers Nutrition 0.000 description 6
- 238000009826 distribution Methods 0.000 description 5
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- 229910052710 silicon Inorganic materials 0.000 description 5
- 239000010703 silicon Substances 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 238000001125 extrusion Methods 0.000 description 4
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 229920002635 polyurethane Polymers 0.000 description 3
- 239000004814 polyurethane Substances 0.000 description 3
- 238000004220 aggregation Methods 0.000 description 2
- 230000002776 aggregation Effects 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 239000003599 detergent Substances 0.000 description 2
- 239000004750 melt-blown nonwoven Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 238000004080 punching Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 238000009987 spinning Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000002759 woven fabric Substances 0.000 description 2
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 239000004925 Acrylic resin Substances 0.000 description 1
- 239000006173 Good's buffer Substances 0.000 description 1
- 229920002292 Nylon 6 Polymers 0.000 description 1
- 244000137852 Petrea volubilis Species 0.000 description 1
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 238000007605 air drying Methods 0.000 description 1
- 238000003556 assay Methods 0.000 description 1
- 238000003486 chemical etching Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000003292 diminished effect Effects 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000004088 foaming agent Substances 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 229920001568 phenolic resin Polymers 0.000 description 1
- 239000005011 phenolic resin Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000193 polymethacrylate Polymers 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000007790 scraping Methods 0.000 description 1
- 229920005992 thermoplastic resin Polymers 0.000 description 1
- 238000009941 weaving Methods 0.000 description 1
- 238000001238 wet grinding Methods 0.000 description 1
Images
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B37/00—Lapping machines or devices; Accessories
- B24B37/11—Lapping tools
- B24B37/20—Lapping pads for working plane surfaces
- B24B37/24—Lapping pads for working plane surfaces characterised by the composition or properties of the pad materials
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
- B24D11/00—Constructional features of flexible abrasive materials; Special features in the manufacture of such materials
- B24D11/02—Backings, e.g. foils, webs, mesh fabrics
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
- B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
- B24D3/02—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent
- B24D3/20—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents the constituent being used as bonding agent and being essentially organic
- B24D3/22—Rubbers synthetic or natural
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/005—Synthetic yarns or filaments
- D04H3/009—Condensation or reaction polymers
- D04H3/011—Polyesters
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
- D04H3/10—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between yarns or filaments made mechanically
- D04H3/105—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with bonds between yarns or filaments made mechanically by needling
-
- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
- D04H3/00—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length
- D04H3/08—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating
- D04H3/12—Non-woven fabrics formed wholly or mainly of yarns or like filamentary material of substantial length characterised by the method of strengthening or consolidating with filaments or yarns secured together by chemical or thermo-activatable bonding agents, e.g. adhesives, applied or incorporated in liquid or solid form
Definitions
- the present invention relates to a polishing pad for use in a chemical mechanical polishing, and a method of producing the polishing pad.
- CMP Chemical mechanical polishing
- ingots of monocrystalline silicon are sliced first.
- the wafers are usually lapped to make them flat for subsequently chemical etching.
- a polishing process is required after the etching process.
- a polishing pad together with slurry reacts chemically with the silicon atoms on the surface of the wafer to make the reacted surface softer than the underlying silicon.
- the reacted surface is continually wiped away causing fresh silicon to be exposed to the slurry and the polishing pad.
- a conventional polishing pad comprises a base material having a surface for polishing a substrate.
- the surface comprises fabric and an elastomer embedded into the fabric. Fibers of the fabric along with the elastomer have the functions of carrying the slurry and removing the reacted surface from the wafer in the polishing process.
- the nonwoven fabric is commonly used in the base material.
- a conventional nonwoven fabric uses directional or non-directional short fibers (usually having a length of less than 10 cm) for forming fabric without weaving.
- the nonwoven fabric usually comprises composite nonwoven fabric, needle-punched nonwoven fabric, melt-blown nonwoven fabric, spunbonded nonwoven fabric, dry-laid nonwoven fabric, wet-laid nonwoven fabric, stitch bonded nonwoven fabric, and spunlace nonwoven fabric.
- the short fibers should be made through a cording process, and a needle-punching process is also needed when manufacturing needle-punched nonwoven fabric.
- Such processes result in an uneven distribution of the fibers, and aggregations of fibers are easily observed in a nonwoven fabric.
- a breakage of the fibers also occurs due to these processes.
- the uneven distribution of the elastomer due to the uneven distribution of the fibers affects the cell size made of the fibers and the elastomer, hardness, uniformity, density of the elastomer, and thickness, and the slurry cannot flow smoothly and polishing particles in the slurry cannot diffuse evenly. Balling is commonly observed when polishing. Besides, the residues formed during polishing tend to stay on the surface of the polishing pad and their removal is difficult; as a result, the residues scrape and damage the substrate to be polished.
- One object of the present invention is to provide a polishing pad comprising a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of bundles of first long fibers and an elastomer embedded into the bundles.
- the bundles of first long fibers are entangled with each other.
- Another object of the present invention is to provide a polishing system comprising:
- Another object of the present invention is to provide a method of polishing a substrate.
- the method comprises a step of using the polishing pad mentioned above to polish a surface of the substrate.
- Still another object of the present invention is to provide a method of producing the polishing pad described above.
- the method comprises steps of: (a) providing a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of bundles of first long fibers and the bundles of first long fibers are entangled with each other; (b) impregnating the surface of the base material with an elastomer solution; and (c) curing the elastomer impregnated in the surface of the base material.
- FIG. 1 shows a view under a transmission electron microscope of the conventional polishing pad.
- FIG. 2 shows a view under a transmission electron microscope of the polishing pad according to the second embodiment of the invention.
- the present invention provides a polishing pad comprising a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of bundles of first long fibers and an elastomer embedded into the bundles.
- the bundles of first long fibers are entangled with each other.
- the bundles of first long fibers are randomly entangled with each other.
- Such base material usually comprises non-woven fabric.
- non-woven fabric refers to a manufactured sheet, web or mat of directionally or randomly orientated fibers, bonded by friction, and/or cohesion and/or adhesion, excluding paper and products which are woven, knitted, tufted, stitch-bonded incorporating binding yarns or filaments, or felted by wet-milling, whether or not additionally needled.
- the fibers may be of natural or man-made origin. They may be staple or continuous filaments or be formed in situ.
- the non-woven fabric usually comprises composite nonwoven fabric, needle-punched nonwoven fabric, melt-blown nonwoven fabric, spunbonded nonwoven fabric, dry-laid nonwoven fabric, wet-laid nonwoven fabric, stitch bonded nonwoven fabric, and spunlace nonwoven fabric.
- the non-woven fabric has a better material property.
- the bundle of first long fibers according to the invention twist together, entwine into a confusing mass and are snarled.
- the conventional short fibers only distribute randomly without entangling with each other and without twist together.
- the bundles of first long fibers are oriented in a predetermined direction as shown in FIG. 2 .
- a predetermined direction refers to any given orientation of the bundles of first long fibers.
- the predetermined direction is planned in advance.
- Such base material usually comprises woven fabric.
- the bundles of first long fibers are parallel to the surface for polishing a substrate.
- the bundles of first long fibers comprise a first bundle and a second bundle, and the first bundle is surrounded by the second bundle. Moreover, the first bundle is partially or totally surrounded by the second bundle.
- the first bundle comprises a first part, and the first part is parallel to each other; the second bundle comprises a second part placed between the first parts; and the second part is vertical to the first parts.
- the base material is used in a roll-to-roll manner that improves batch uniformity.
- the term “fiber” refers to a single fiber or composite fibers, preferably composite fibers.
- the fiber is selected in accordance with the substrate to be polished.
- the fibers of the surface of the base material provide protrusions for polishing and also provide a scaffold allowing the elastomers deposed in the space defined by the scaffold.
- Artisans skilled in this field can choose suitable kinds of fibers and coordinate the elastomer polymer with the fibers according to the disclosure of the specification.
- the first long fiber is made of at least one material selected from the group consisting of polyamide, terephthalamide, polyester, polymethyl methacrylate, polyethylene terephthalate, polyacrylonitrile, and mixtures thereof.
- long fiber refers to a fiber having a length more than about 10 cm.
- the shape of the long fiber is continuous and the length is unlimited in theory.
- the long fiber is easily twisted for improving the strength and stress.
- the fiber is a sea-island fiber.
- the sea-island fiber is produced by conjugate-spinning or blend-spinning two polymers in a sea-island manner
- the sea-island fiber is treated by weight reducing to reduce the proportion of the sea component.
- the methods of weight reducing the sea component are well known to artisans skilled in this field, such as those methods using sodium hydroxide or toluene.
- the long fiber after reducing the sea component is divided into 0.05 to 0.0001 Deniers.
- the base material comprises a fiber mat.
- the term “fiber mat” refers to a thin and strengthened material designed for improving the strength of the fibers according to the invention.
- the material of the fiber mat is preferably polyamide, polyester, or polyolefin.
- the fiber mat preferably comprises second long fibers.
- the second long fibers can be woven or non-woven to form the fiber mat.
- the fiber mat comprises meshes, and the second long fibers of the fiber mat and the first long fibers are intertwined with each other.
- the fiber mat has a thickness of 0.01 to 1.0 mm.
- the fiber mat has a weight per area unit of 10 to 200 g/m 2 .
- the fiber mat has a mesh of 10 to 150.
- 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 the surface of the substrate to be polished.
- the elastomers are foam resins.
- the term “foam resin” refers to a material containing a thermoplastic resin and a thermodecomposing foaming agent.
- the elastomers are at least one selected from the group consisting of polyurethane, polyamide, polycarbonate, polyaminonitrile, polymethacrylate, epoxyl resin, phenolic resins, polymethyl methacrylate, polyaminoester, vinylbenzene polymer, acrylic resin, and polyurethane.
- the polishing pad according to the invention can avoid the defects of the conventional polishing pad made of short fibers. Because the bundle of first long fibers are able to form the base mateiral without a cording process or a needle-punching process, the uneven distribution of the fibers, aggregations of fibers and a breakage of the fibers due to the processes are then avoided. As a result, the elastomer according to the invention is evenly embedded into the fibers. Furthermore, the cell size made of the fibers and the elastomer, hardness, uniformity, density of the elastomer, thickness, compression ratio, and recover rate after compression are all improved. The slurry can flow smoothly and polishing particles can diffuse evenly as well. The polishing pad according to the invention does not damage the surface of the substrate to be polished and balling is diminished dramatically. Furthermore, the polishing efficiency is satisfied when the polishing pad according to the invention is applied.
- the present invention also provides a polishing system comprising:
- the present invention also provides a method of polishing a substrate.
- the method comprises a step of using the polishing pad as mentioned above to polish a surface of the substrate.
- the present invention further provides a method of producing the polishing pad as mentioned above.
- the method comprises steps of: (a) providing a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of bundles of first long fibers, and the bundles of first long fibers are entangled with each other; (b) impregnating the surface of the base material with an elastomer solution; and (c) curing the elastomer impregnated in the surface of the base material.
- the manner of impregnating the base material with an elastomer solution is the method of dipping the fibers with the elastomer solution.
- the conditions for impregnation are well known to artisans skilled in this field.
- Suitable solvents used in the elastomer solution include dimethylformamide (DMF).
- the elastomer solution optionally comprises additives such as a detergent.
- the elastomer has a concentration ranging from 2 wt % to 60 wt % in the elastomer solution.
- step (b) further comprises impregnating the entire base material with the elastomer solution.
- step (c) of the method the manner of curing the elastomer impregnated in the base material is to cure the elastomer in the base material.
- the base material is put into a curing solution for curing.
- the curing solution comprises 0 to 40 wt % dimethylformamide in water.
- the conditions for curing are well known to artisans skilled in this field.
- the curing is carried out at room temperature and pressure.
- the method of producing a polishing pad further comprises a step (c1) of washing the base material after step (c).
- the purpose of washing is to remove residues from the polishing pad.
- water is used in washing and extrusion wheels are optionally used. The conditions for washing are well known to artisans skilled in this field.
- the base material is washed in water at 50 to 90° C. and then subjected to the extrusion wheels several times.
- the method of producing a polishing pad further comprises a step (c2) of drying the base material after step (c1).
- the purpose of drying is to remove the excess solvent from step (c1).
- the conditions for drying are well known to artisans skilled in this field.
- the drying is air-drying, and the drying temperature is in the range of 100° C. to 160° C.
- the method of producing a polishing pad further comprises a step (c3) of mechanically polishing the surface of the base material and the elastomer.
- the mechanical polishing can be accomplished using a sand blast.
- the conditions for mechanical polishing are well known to artisans skilled in this field. More preferably, the fibers are exposed to the surface of the base material after mechanical polishing.
- steps (b) and (c) are repeated several times.
- the kind of the elastomer used in each time can be different or the same.
- Base Material A polyethylene terephthalate chip was melt spun at 260° C. to 300° C. and quenched at room temperature. The chip was then subjected to a calender machine to obtain a base material with 10 to 150 meshes and having a thickness of 0.7 mm and a weight of 150 g/m 2 .
- Fiber mat A fabric was slivered for to obtain a mat. Several sheets of the net were laid up and then woven with 70 Deniers of Nylon 6 yarn to obtain a 30-mesh sheet having a thickness of 0.15 mm and a weight of 35 g/m 2 . The sheet was then needle punched (700 times/m 2 ) to obtain a fiber mat with a weight of 475 g/m 2 .
- Impregnating The base material was impregnated in an elastomer solution with a viscosity of 700 to 850 Cps.
- the elastomer solution comprises 50 wt % of polyurethane, 49 wt % of dimethylformamide and 1 wt % of detergent.
- Curing The base material, after impregnating, was put into a curing solution comprising 25 wt % dimethylformamide in water to mold the elastomer impregnated in the fibers.
- polishing After drying, the base material was subjected to mechanical polishing with #150 and #400 sand paper at 1200 and 1300 rpm, and a 1.28 mm product with a flat surface was obtained.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Textile Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Finish Polishing, Edge Sharpening, And Grinding By Specific Grinding Devices (AREA)
Abstract
The present invention mainly relates to a polishing pad and method of producing the same. The polishing pad comprises a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of bundles of first long fibers and an elastomer embedded into the bundles. The bundles of first long fibers are entangled with each other.
Description
- This application is a Continuation-in-part of the pending U.S. patent application Ser. No. 12/883,509 filed on Sep. 16, 2010, all of which is hereby incorporated by reference in its entirety.
- Although incorporated by reference in its entirety, no arguments or disclaimers made in the parent application apply to this CIP application. Any disclaimer that may have occurred during the prosecution of the above-referenced application(s) is hereby expressly rescinded. Consequently, the Patent Office is asked to review the new set of claims in view of the entire prior art of record and any search that the Office deems appropriate.
- 1. Field of the Invention
- The present invention relates to a polishing pad for use in a chemical mechanical polishing, and a method of producing the polishing pad.
- 2. Description of the Related Art
- Chemical mechanical polishing (CMP) is a procedure for planarizing the surface of a substrate with a polishing pad. CMP is generally applied to polishing lens, mirrors, substrates of liquid crystal displays, silicon wafers, and oxidation and/or metal layers on silicon wafers.
- Taking silicon wafers as an example, ingots of monocrystalline silicon are sliced first. The wafers are usually lapped to make them flat for subsequently chemical etching. A polishing process is required after the etching process. During the polishing process, a polishing pad together with slurry reacts chemically with the silicon atoms on the surface of the wafer to make the reacted surface softer than the underlying silicon. Furthermore, the reacted surface is continually wiped away causing fresh silicon to be exposed to the slurry and the polishing pad.
- As shown in
FIG. 1 , a conventional polishing pad comprises a base material having a surface for polishing a substrate. The surface comprises fabric and an elastomer embedded into the fabric. Fibers of the fabric along with the elastomer have the functions of carrying the slurry and removing the reacted surface from the wafer in the polishing process. The nonwoven fabric is commonly used in the base material. A conventional nonwoven fabric uses directional or non-directional short fibers (usually having a length of less than 10 cm) for forming fabric without weaving. According to the manner of forming the fabric, the nonwoven fabric usually comprises composite nonwoven fabric, needle-punched nonwoven fabric, melt-blown nonwoven fabric, spunbonded nonwoven fabric, dry-laid nonwoven fabric, wet-laid nonwoven fabric, stitch bonded nonwoven fabric, and spunlace nonwoven fabric. However, the short fibers should be made through a cording process, and a needle-punching process is also needed when manufacturing needle-punched nonwoven fabric. Such processes result in an uneven distribution of the fibers, and aggregations of fibers are easily observed in a nonwoven fabric. In addition, a breakage of the fibers also occurs due to these processes. Furthermore, after embedding the elastomer into the fabric, the uneven distribution of the elastomer due to the uneven distribution of the fibers affects the cell size made of the fibers and the elastomer, hardness, uniformity, density of the elastomer, and thickness, and the slurry cannot flow smoothly and polishing particles in the slurry cannot diffuse evenly. Balling is commonly observed when polishing. Besides, the residues formed during polishing tend to stay on the surface of the polishing pad and their removal is difficult; as a result, the residues scrape and damage the substrate to be polished. - One object of the present invention is to provide a polishing pad comprising a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of bundles of first long fibers and an elastomer embedded into the bundles. The bundles of first long fibers are entangled with each other.
- Another object of the present invention is to provide a polishing system comprising:
-
- a polishing pad as mentioned above;
- a substrate to be polished;
- a slurry, wherein the slurry together with the polishing pad react chemically with the surface of the substrate to be polished;
- wherein the first long fibers and the elastomer have the functions of carrying the slurry and removing the reacted surface of the substrate to be polished in a polishing process.
- Another object of the present invention is to provide a method of polishing a substrate. The method comprises a step of using the polishing pad mentioned above to polish a surface of the substrate.
- Still another object of the present invention is to provide a method of producing the polishing pad described above. The method comprises steps of: (a) providing a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of bundles of first long fibers and the bundles of first long fibers are entangled with each other; (b) impregnating the surface of the base material with an elastomer solution; and (c) curing the elastomer impregnated in the surface of the base material.
-
FIG. 1 shows a view under a transmission electron microscope of the conventional polishing pad. -
FIG. 2 shows a view under a transmission electron microscope of the polishing pad according to the second embodiment of the invention. - The present invention provides a polishing pad comprising a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of bundles of first long fibers and an elastomer embedded into the bundles. The bundles of first long fibers are entangled with each other.
- In the first embodiment of the invention, the bundles of first long fibers are randomly entangled with each other. Such base material usually comprises non-woven fabric. As used herein, “non-woven fabric” refers to a manufactured sheet, web or mat of directionally or randomly orientated fibers, bonded by friction, and/or cohesion and/or adhesion, excluding paper and products which are woven, knitted, tufted, stitch-bonded incorporating binding yarns or filaments, or felted by wet-milling, whether or not additionally needled. The fibers may be of natural or man-made origin. They may be staple or continuous filaments or be formed in situ. According to the method of forming the web, the non-woven fabric usually comprises composite nonwoven fabric, needle-punched nonwoven fabric, melt-blown nonwoven fabric, spunbonded nonwoven fabric, dry-laid nonwoven fabric, wet-laid nonwoven fabric, stitch bonded nonwoven fabric, and spunlace nonwoven fabric. Compared with woven fabric, the non-woven fabric has a better material property.
- In one embodiment of the invention, the bundle of first long fibers according to the invention twist together, entwine into a confusing mass and are snarled. On the contrary, the conventional short fibers only distribute randomly without entangling with each other and without twist together.
- In the second embodiment of the invention, the bundles of first long fibers are oriented in a predetermined direction as shown in
FIG. 2 . As used herein, “a predetermined direction” refers to any given orientation of the bundles of first long fibers. Compared to the random distribution of the bundles of first long fibers as described in the first embodiment, the predetermined direction is planned in advance. Such base material usually comprises woven fabric. - Preferably, the bundles of first long fibers are parallel to the surface for polishing a substrate.
- Preferably, the bundles of first long fibers comprise a first bundle and a second bundle, and the first bundle is surrounded by the second bundle. Moreover, the first bundle is partially or totally surrounded by the second bundle.
- More preferably, the first bundle comprises a first part, and the first part is parallel to each other; the second bundle comprises a second part placed between the first parts; and the second part is vertical to the first parts.
- In one preferred embodiment of the invention, the base material is used in a roll-to-roll manner that improves batch uniformity.
- As used herein, the term “fiber” refers to a single fiber or composite fibers, preferably composite fibers. The fiber is selected in accordance with the substrate to be polished. The fibers of the surface of the base material provide protrusions for polishing and also provide a scaffold allowing the elastomers deposed in the space defined by the scaffold. Artisans skilled in this field can choose suitable kinds of fibers and coordinate the elastomer polymer with the fibers according to the disclosure of the specification. Preferably, the first long fiber is made of at least one material selected from the group consisting of polyamide, terephthalamide, polyester, polymethyl methacrylate, polyethylene terephthalate, polyacrylonitrile, and mixtures thereof.
- As defined in this field, the term “long fiber” refers to a fiber having a length more than about 10 cm. The shape of the long fiber is continuous and the length is unlimited in theory. The long fiber is easily twisted for improving the strength and stress.
- In one preferred embodiment of the invention, the fiber is a sea-island fiber. As used herein, the term “sea-island fiber,” also known as “sea-island type composite fiber,” refers to a fiber comprising a sea component and an island component. For example, the sea-island fiber is produced by conjugate-spinning or blend-spinning two polymers in a sea-island manner In one preferred embodiment of the invention, the sea-island fiber is treated by weight reducing to reduce the proportion of the sea component. The methods of weight reducing the sea component are well known to artisans skilled in this field, such as those methods using sodium hydroxide or toluene. Preferably, the long fiber after reducing the sea component is divided into 0.05 to 0.0001 Deniers.
- In one preferred embodiment of the invention, the base material comprises a fiber mat. As used herein, the term “fiber mat” refers to a thin and strengthened material designed for improving the strength of the fibers according to the invention. The material of the fiber mat is preferably polyamide, polyester, or polyolefin. The fiber mat preferably comprises second long fibers. The second long fibers can be woven or non-woven to form the fiber mat. The fiber mat comprises meshes, and the second long fibers of the fiber mat and the first long fibers are intertwined with each other. Preferably, the fiber mat has a thickness of 0.01 to 1.0 mm. The fiber mat has a weight per area unit of 10 to 200 g/m2. In addition, the fiber mat has a mesh of 10 to 150.
- 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 the surface of the substrate to be polished. In one preferred embodiment of the invention, the elastomers are foam resins. As used herein, the term “foam resin” refers to a material containing a thermoplastic resin and a thermodecomposing foaming agent. Preferably, the elastomers are at least one selected from the group consisting of polyurethane, polyamide, polycarbonate, polyaminonitrile, polymethacrylate, epoxyl resin, phenolic resins, polymethyl methacrylate, polyaminoester, vinylbenzene polymer, acrylic resin, and polyurethane.
- The polishing pad according to the invention can avoid the defects of the conventional polishing pad made of short fibers. Because the bundle of first long fibers are able to form the base mateiral without a cording process or a needle-punching process, the uneven distribution of the fibers, aggregations of fibers and a breakage of the fibers due to the processes are then avoided. As a result, the elastomer according to the invention is evenly embedded into the fibers. Furthermore, the cell size made of the fibers and the elastomer, hardness, uniformity, density of the elastomer, thickness, compression ratio, and recover rate after compression are all improved. The slurry can flow smoothly and polishing particles can diffuse evenly as well. The polishing pad according to the invention does not damage the surface of the substrate to be polished and balling is diminished dramatically. Furthermore, the polishing efficiency is satisfied when the polishing pad according to the invention is applied.
- The present invention also provides a polishing system comprising:
-
- a polishing pad as mentioned above;
- a substrate to be polished;
- a slurry, wherein the slurry together with the polishing pad react chemically with the surface of the substrate to be polished;
- wherein the first long fibers and the elastomer have the functions of carrying the slurry and removing the reacted surface of the substrate to be polished in a polishing process.
- The present invention also provides a method of polishing a substrate. The method comprises a step of using the polishing pad as mentioned above to polish a surface of the substrate.
- The present invention further provides a method of producing the polishing pad as mentioned above. The method comprises steps of: (a) providing a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of bundles of first long fibers, and the bundles of first long fibers are entangled with each other; (b) impregnating the surface of the base material with an elastomer solution; and (c) curing the elastomer impregnated in the surface of the base material.
- In step (b) of the method, the manner of impregnating the base material with an elastomer solution is the method of dipping the fibers with the elastomer solution. The conditions for impregnation are well known to artisans skilled in this field. Suitable solvents used in the elastomer solution include dimethylformamide (DMF). The elastomer solution optionally comprises additives such as a detergent. Preferably, the elastomer has a concentration ranging from 2 wt % to 60 wt % in the elastomer solution.
- Preferably, step (b) further comprises impregnating the entire base material with the elastomer solution.
- In step (c) of the method, the manner of curing the elastomer impregnated in the base material is to cure the elastomer in the base material. In one embodiment of the invention, the base material is put into a curing solution for curing. Preferably, the curing solution comprises 0 to 40 wt % dimethylformamide in water. The conditions for curing are well known to artisans skilled in this field. Preferably, the curing is carried out at room temperature and pressure.
- In one preferred embodiment of the invention, the method of producing a polishing pad further comprises a step (c1) of washing the base material after step (c). The purpose of washing is to remove residues from the polishing pad. In one embodiment of the invention, water is used in washing and extrusion wheels are optionally used. The conditions for washing are well known to artisans skilled in this field. Preferably, the base material is washed in water at 50 to 90° C. and then subjected to the extrusion wheels several times.
- In one more preferred embodiment of the invention, the method of producing a polishing pad further comprises a step (c2) of drying the base material after step (c1). The purpose of drying is to remove the excess solvent from step (c1). The conditions for drying are well known to artisans skilled in this field. In one embodiment of the invention, the drying is air-drying, and the drying temperature is in the range of 100° C. to 160° C.
- Preferably, the method of producing a polishing pad further comprises a step (c3) of mechanically polishing the surface of the base material and the elastomer. For example, the mechanical polishing can be accomplished using a sand blast. The conditions for mechanical polishing are well known to artisans skilled in this field. More preferably, the fibers are exposed to the surface of the base material after mechanical polishing.
- In one preferred embodiment of the invention, steps (b) and (c) are repeated several times. The kind of the elastomer used in each time can be different or the same.
- The following Examples are given for the purpose of illustration only and are not intended to limit the scope of the present invention.
- Base Material: A polyethylene terephthalate chip was melt spun at 260° C. to 300° C. and quenched at room temperature. The chip was then subjected to a calender machine to obtain a base material with 10 to 150 meshes and having a thickness of 0.7 mm and a weight of 150 g/m2.
- Fiber mat: A fabric was slivered for to obtain a mat. Several sheets of the net were laid up and then woven with 70 Deniers of Nylon 6 yarn to obtain a 30-mesh sheet having a thickness of 0.15 mm and a weight of 35 g/m2. The sheet was then needle punched (700 times/m2) to obtain a fiber mat with a weight of 475 g/m2.
- Impregnating: The base material was impregnated in an elastomer solution with a viscosity of 700 to 850 Cps. The elastomer solution comprises 50 wt % of polyurethane, 49 wt % of dimethylformamide and 1 wt % of detergent.
- Curing: The base material, after impregnating, was put into a curing solution comprising 25 wt % dimethylformamide in water to mold the elastomer impregnated in the fibers.
- Washing: The residues and the excess curing solution were removed by extrusion wheels. The base material was then washed in water at 80° C. and then subjected to the extrusion wheels several times.
- Drying: The base material, after washing, was then dried at 140° C.
- Polishing: After drying, the base material was subjected to mechanical polishing with #150 and #400 sand paper at 1200 and 1300 rpm, and a 1.28 mm product with a flat surface was obtained.
- Assay: The polishing pad with a long fiber according to the invention (long fiber) and a conventional polishing pad with a short fiber (short fiber) was assayed and the results are shown in Table 1. The compression ratio and recover rate after compression of the polishing pad according to the invention are both improved compared with the conventional polishing pad.
-
TABLE 1 Recover rate after Thickness (mm) Compression ratio (%) compression (%) Long fiber 1.40 19.63 92.34 Short fiber 1.35 15.99 89.67 - 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 (18)
1. A polishing pad comprising a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of bundles of first long fibers and an elastomer embedded into the bundles, and the bundles of first long fibers are entangled with each other.
2. The polishing pad according to claim 1 , wherein the bundles of first long fibers are randomly entangled with each other.
3. The polishing pad according to claim 1 , wherein the bundles of first long fibers are oriented in a predetermined direction.
4. The polishing pad according to claim 1 , wherein the bundles of first long fibers are parallel to the surface for polishing a substrate.
5. The polishing pad according to claim 1 , wherein the bundles of first long fibers comprise a first bundle and a second bundle, and the first bundle is surrounded by the second bundle.
6. The polishing pad according to claim 5 , wherein the first bundle comprises a first part, and the first part is parallel to each other; the second bundle comprises a second part placed between the first parts; and the second part is vertical to the first parts.
7. The polishing pad according to claim 1 , wherein the first long fiber is selected from the group consisting of a single fiber and composite fibers.
8. The polishing pad according to claim 1 , wherein the first long fiber is made of at least one material selected from the group consisting of polyamide, terephthalamide, polyester, polymethyl methacrylate, polyethylene terephthalate, polyacrylonitrile, and mixtures thereof.
9. The polishing pad according to claim 1 , wherein the length of the first long fiber is more than about 10 cm.
10. The polishing pad according to claim 1 , wherein the first long fiber is a sea-island fiber.
11. The polishing pad according to claim 1 , wherein the base material further comprises a fiber mat comprising meshes, and the fiber mat comprises second long fibers, and the second long fibers and the first long fibers are intertwined with each other.
12. The polishing pad according to claim 1 , wherein the elastomer is a foam resin.
13. A polishing system comprising:
a polishing pad according to claim 1 ;
a substrate to be polished;
a slurry, wherein the slurry together with the polishing pad react chemically with the surface of the substrate to be polished;
wherein the first long fibers and the elastomer have the functions of carrying the slurry and removing the reacted surface of the substrate to be polished in a polishing process.
14. A method of polishing a substrate, the method comprising a step of using the polishing pad according to claim 1 to polish a surface of the substrate.
15. A method of producing the polishing pad according to claim 1 , comprising steps of:
(a) providing a base material having a surface for polishing a substrate, wherein the surface comprises a plurality of bundles of first long fibers, and the bundles of first long fibers are entangled with each other;
(b) impregnating the surface of the base material with an elastomer solution; and
(c) curing the elastomer impregnated in the surface of the base material.
16. The method according to claim 15 , further comprising a step (c1) of washing the surface of the base material after the step (c).
17. The method according to claim 16 , further comprising a step (c2) of drying the surface of the base material after the step (c1).
18. The method according to claim 15 , further comprising a step (c3) of mechanically polishing the surface of the base material and the elastomer after the step (c).
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US13/555,868 US20120302142A1 (en) | 2010-09-16 | 2012-07-23 | Polishing pad and method of producing the same |
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US12/883,509 US20110003536A1 (en) | 2007-01-12 | 2010-09-16 | Polishing Pad and Method of Producing the Same |
US13/555,868 US20120302142A1 (en) | 2010-09-16 | 2012-07-23 | Polishing pad and method of producing the same |
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US12/883,509 Continuation-In-Part US20110003536A1 (en) | 2007-01-12 | 2010-09-16 | Polishing Pad and Method of Producing the Same |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20170050288A1 (en) * | 2015-08-17 | 2017-02-23 | Nan Ya Plastics Corporation | Composite polishing pad having layers with different hardness and process for producing the same |
US20180009079A1 (en) * | 2015-01-30 | 2018-01-11 | Applied Materials, Inc. | Multi-layered nano-fibrous cmp pads |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4728552A (en) * | 1984-07-06 | 1988-03-01 | Rodel, Inc. | Substrate containing fibers of predetermined orientation and process of making the same |
US6635211B2 (en) * | 2001-06-25 | 2003-10-21 | Taiwan Semiconductor Manufacturing Co. Ltd | Reinforced polishing pad for linear chemical mechanical polishing and method for forming |
US20040162013A1 (en) * | 2000-06-23 | 2004-08-19 | International Business Machines Corporation | Polishing pads with polymer filled fibrous web, and methods for fabricating and using same |
US20080299879A1 (en) * | 2007-05-29 | 2008-12-04 | San Fang Chemical Industry Co., Ltd. | Polishing pad, the use thereof and the method for manufacturing the same |
US20090098814A1 (en) * | 2007-10-05 | 2009-04-16 | Chien-Min Sung | Polymeric Fiber CMP Pad and Associated Methods |
US20110171890A1 (en) * | 2008-08-08 | 2011-07-14 | Kuraray Co., Ltd. | Polishing pad and method for manufacturing the polishing pad |
-
2012
- 2012-07-23 US US13/555,868 patent/US20120302142A1/en not_active Abandoned
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4728552A (en) * | 1984-07-06 | 1988-03-01 | Rodel, Inc. | Substrate containing fibers of predetermined orientation and process of making the same |
US20040162013A1 (en) * | 2000-06-23 | 2004-08-19 | International Business Machines Corporation | Polishing pads with polymer filled fibrous web, and methods for fabricating and using same |
US6635211B2 (en) * | 2001-06-25 | 2003-10-21 | Taiwan Semiconductor Manufacturing Co. Ltd | Reinforced polishing pad for linear chemical mechanical polishing and method for forming |
US20080299879A1 (en) * | 2007-05-29 | 2008-12-04 | San Fang Chemical Industry Co., Ltd. | Polishing pad, the use thereof and the method for manufacturing the same |
US20090098814A1 (en) * | 2007-10-05 | 2009-04-16 | Chien-Min Sung | Polymeric Fiber CMP Pad and Associated Methods |
US20110171890A1 (en) * | 2008-08-08 | 2011-07-14 | Kuraray Co., Ltd. | Polishing pad and method for manufacturing the polishing pad |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20180009079A1 (en) * | 2015-01-30 | 2018-01-11 | Applied Materials, Inc. | Multi-layered nano-fibrous cmp pads |
US10800000B2 (en) * | 2015-01-30 | 2020-10-13 | Applied Materials, Inc. | Multi-layered nano-fibrous CMP pads |
US20170050288A1 (en) * | 2015-08-17 | 2017-02-23 | Nan Ya Plastics Corporation | Composite polishing pad having layers with different hardness and process for producing the same |
US9975214B2 (en) * | 2015-08-17 | 2018-05-22 | Nan Ya Plastics Corporation | Composite polishing pad having layers with different hardness and process for producing the same |
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