JP2008149458A - Composition for polishing pad and polishing pad using this composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for a polishing pad superior in moldability and abrasion resistance, and the polishing pad using this composition. <P>SOLUTION: This polishing pad is provided by performing cross-linking processing on a kneading material including uncross-linked 1,2-poybutadiene, an uncross-linked ethylene-vinyl acetate copolymer, a β-cyclodextrin particle and organic peroxide in a metal mold. The provided polishing pad is composed of the composition for the polishing pad including a water insoluble matrix including 10 mass% or more of cross-linked 1,2-polybutadiene and a cross-linked ethylene-vinyl acetate copolymer, and water soluble particles dispersed in the water insoluble matrix and composed of β-cyclodextrin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a polishing pad composition and a polishing pad using the same. More specifically, the present invention relates to a polishing pad composition excellent in moldability and wear resistance, and a polishing pad using the same. The present invention is widely used in the manufacture of semiconductor devices. It is particularly suitable for chemical mechanical polishing of the surface of a semiconductor wafer or the like.

  In recent years, chemical mechanical polishing (CMP) has attracted attention as a method for forming a flat surface. In CMP, a slurry, which is an aqueous dispersion in which abrasive grains are dispersed, is supplied to the polishing pad surface while sliding the polishing pad and the surface to be polished, and a hole (hereinafter referred to as “pore”) opened in the polishing pad surface. Polishing is performed by retaining the slurry.

  The present inventors have found that a polishing pad using a polishing pad composition containing a crosslinked polymer can exhibit excellent performance. This technique is disclosed in Japanese Patent Laid-Open No. 2001-334455. In addition, conventionally known techniques related to polishing pads and the like include JP-T-8-500622, JP-A No. 2000-34416, JP-A No. 2000-33552 and JP-A No. 2000-34416. . However, it is necessary to further improve various performances.

  This invention is made | formed in view of the said situation, and it aims at providing the composition for polishing pads excellent in the moldability and abrasion resistance, and a polishing pad using the same.

The present invention provides the following polishing pad composition (1) to ( 6 ) and a polishing pad using the same.
( 1 ) In a polishing pad composition comprising a water-insoluble matrix and water-soluble particles dispersed in the water-insoluble matrix,
It is obtained by crosslinking a composition for an uncrosslinked polishing pad containing an uncrosslinked water-insoluble matrix and water-soluble particles dispersed in the uncrosslinked water-insoluble matrix,
The uncrosslinked water-insoluble matrix contains uncrosslinked 1,2-polybutadiene and an uncrosslinked ethylene-vinyl acetate copolymer,
The uncrosslinked 1,2-polybutadiene is 10% by mass or more when the entire uncrosslinked water-insoluble matrix is 100% by mass,
The uncrosslinked 1,2-polybutadiene is 50% by mass or more when the total of the uncrosslinked 1,2-polybutadiene and the uncrosslinked ethylene-vinyl acetate copolymer is 100% by mass. Composition for polishing pad.
( 2 ) The composition for polishing pad according to ( 1 ), wherein the water-insoluble matrix further contains another crosslinked polymer excluding both the crosslinked 1,2-polybutadiene and the crosslinked ethylene-vinyl acetate copolymer. object.
( 3 ) The other crosslinked polymer is at least one of a crosslinked polyethylene polymer, a crosslinked acrylonitrile-styrene-butadiene copolymer, and a crosslinked styrene-butadiene-styrene copolymer, as described in ( 2 ) above. Polishing pad composition.
(4) The polishing pad composition according to any one of (1) to (3), wherein the water-soluble particles have an average particle size of 0.1 to 500 μm.
(5) The composition for polishing pad according to any one of (1) to (4), wherein the crosslinking treatment uses an organic peroxide.
( 6 ) A polishing pad comprising a polishing portion comprising the polishing pad composition according to any one of (1) to ( 5 ).

According to the polishing pad composition of the present invention, a polishing pad and a multilayer polishing pad having excellent polishing performance can be obtained efficiently and stably. In addition, a polishing pad and a multilayer polishing pad having excellent wear resistance can be obtained.
When the other crosslinked polymer is at least one of a crosslinked polyethylene polymer, a crosslinked acrylonitrile-styrene-butadiene copolymer, and a crosslinked styrene-butadiene-styrene copolymer, particularly excellent moldability and resistance. Abrasion can be obtained.
According to the polishing pad of the present invention, it has excellent wear resistance and can exhibit stable polishing performance over a long period of time.

The present invention will be described in detail below.
[1] Polishing pad composition containing crosslinked PBD and other crosslinked polymer (reference invention)
The “water-insoluble matrix” is a parent phase constituting a polishing portion of a polishing pad, which will be described later, and further the entire polishing pad (hereinafter also referred to as “polishing portion and polishing pad”). This water-insoluble matrix contains dispersed water-soluble particles described later. The water-insoluble matrix contains a crosslinked 1,2-polybutadiene (hereinafter also simply referred to as “crosslinked PBD”) and a crosslinked ethylene-vinyl acetate copolymer (hereinafter also simply referred to as “crosslinked EVA”). And other cross-linked polymers except both cross-linked PBD and cross-linked EVA are included.

  The “crosslinked 1,2-polybutadiene” can impart an elastic recovery force to the water-insoluble matrix, and can suppress displacement due to shear stress applied to the polishing portion and the polishing pad during polishing. For this reason, it can suppress that a water-insoluble matrix is extended too much at the time of grinding | polishing and dressing, and plastic deformation is carried out, and it is suppressed that a fuzz is crushed in a short period of time. That is, a good polishing state can be maintained for a long time, and pores can be formed efficiently during dressing. Moreover, it can also suppress that the surface of a grinding | polishing part and a polishing pad fuzzs excessively by dressing, and polishing flatness is not inhibited.

The content of the crosslinked PBD is 10% by mass or more, preferably 15% by mass or more, more preferably 20% by mass or more, when the entire water-insoluble matrix is 100% by mass, 30 It is particularly preferable that the content is at least mass%. However, it is usually 95% by mass or less. If the content of the crosslinked PBD is less than 10% by mass, the effect of containing the crosslinked PBD may not be sufficiently exhibited.
This crosslinked PBD may be crosslinked by any method. That is, for example, it may be chemically crosslinked using an organic peroxide, sulfur, sulfur compound, etc., may be thermally crosslinked by heating, or radiation crosslinked by electron beam irradiation or the like. It may be a thing, and also what was cross-linked by two or more kinds of these cross-linking methods may be used.

  The “other cross-linked polymer” is a cross-linked polymer excluding cross-linked PBD and cross-linked EVA contained in the water-insoluble matrix. By containing other cross-linked polymers, (1) moldability is improved. This moldability includes ease of molding and handling properties. For example, an uncrosslinked product that becomes a water-insoluble matrix is filled in a mold and crosslinked in a mold using a crosslinking agent or the like, and then the obtained molded body (such as a polishing pad and a polishing layer) is removed. There is a case where a molding process is performed. It is possible to reliably prevent the molded body from cracking or chipping when performing this demolding. Further, (2) excellent wear resistance is imparted. For this reason, a long-life polishing part and polishing pad can be obtained.

The kind of other crosslinked polymer is not particularly limited. Other cross-linked polymers include non-cross-linked polymers such as thermoplastic resins, elastomers, rubbers, and curable resins (thermosetting resins, photocurable resins, etc., resins cured by heat, light, etc.) And a crosslinked polymer formed by crosslinking two or more of these uncrosslinked polymers. These can be used alone or in combination.
As thermoplastic resins, polyolefin resins such as polyethylene (excluding EVA), acrylonitrile-styrene-butadiene copolymers (ABS resins, etc.), polystyrene resins, polyacrylic resins {(meth) acrylate resins, etc.], Examples include vinyl ester resins (except EVA), saturated polyester resins, polyamide resins, fluororesins (polyvinylidene fluoride, etc.), polycarbonate resins, polyacetal resins, and the like.

  Elastomers include polyolefin elastomers (excluding EVA), styrene elastomers (styrene-butadiene-styrene copolymers, hydrogenated block copolymers (SEBS), etc.), thermoplastic polyurethane elastomers, thermoplastic polyester elastomers. , Polyamide elastomer, silicone resin elastomer, fluororesin elastomer and the like.

Rubbers include butadiene rubber (high cis butadiene rubber, low cis butadiene rubber, etc.), isoprene rubber, styrene-butadiene rubber, conjugated diene rubber such as styrene-isoprene rubber, acrylonitrile-butadiene rubber, etc. Nitrile rubber, acrylic rubber, ethylene-propylene rubber, ethylene-α-olefin rubber such as ethylene-propylene-diene rubber, and other rubbers such as butyl rubber, silicone rubber, and fluorine rubber.
Examples of the curable resin include urethane resins, epoxy resins, (meth) acrylic resins, unsaturated polyester resins, polyurethane-urea resins, urea resins, silicon resins, phenol resins, and the like.

  These other cross-linked polymers may be cross-linked by any method similar to the cross-linked PBD. Moreover, these other crosslinked polymers may be co-crosslinked with the crosslinked PBD, or may not be co-crosslinked. Further, these other crosslinked polymers may be polymers modified with an acid anhydride group, a carboxyl group, a hydroxyl group, an epoxy group, an amino group, or the like. By the modification, the affinity with crosslinked PBD, water-soluble particles described later, and slurry can be adjusted.

Among the other cross-linked polymers, polyethylene resin, acrylonitrile-styrene-butadiene copolymer, styrene-butadiene-styrene copolymer, polyacrylic resin, vinyl ester resin, saturated polyester resin, polyamide resin, and polyacetal A crosslinked polymer in which at least one kind of the resin is crosslinked or co-crosslinked is preferable. These crosslinked polymers have a great effect of improving moldability and wear resistance. Moreover, there is little softening by water absorption and it is stable with respect to the acid and alkali contained in a slurry.
The content of these other crosslinked polymers is preferably 5% by mass or more, more preferably 10% by mass or more, and more preferably 20% by mass or more, based on 100% by mass of the entire water-insoluble matrix. It is particularly preferred that However, other crosslinked polymers are 90 mass% or less. When the content of the other crosslinked polymer is less than 5% by mass, the effects (1) and (2) may not be sufficiently exhibited.

  The preferable content of the above-mentioned crosslinked PBD and other crosslinked polymers can be a combination of each. That is, for example, the cross-linked PBD is preferably 10 to 95% by mass and the other cross-linked polymer is preferably 5 to 90% by mass, the cross-linked PBD is 15 to 95% by mass and the other cross-linked polymer is 5%. It is more preferable that it is -85 mass%, it is especially preferable that crosslinked PBD is 20-90 mass% and another crosslinked polymer is 10-80 mass%, and crosslinked PBD is 30-80 mass%. And it is especially preferable that another crosslinked polymer is 20-70 mass%.

  The water-insoluble matrix constituting the polishing pad composition contains 10% by mass or more of the crosslinked PBD with respect to the water-insoluble matrix as described above, and contains other crosslinked polymer, whereby JIS K 6251. When a test piece made of a water-insoluble matrix is fractured at 80 ° C. according to the above, the elongation remaining after fracture (hereinafter simply referred to as “residual elongation at break”) can be 100% or less. That is, the total distance between the marked lines after the fracture is not more than twice the distance between the marked lines before the fracture. The residual elongation at break is more preferably 30% or less (more preferably 10% or less, particularly preferably 5% or less, usually 0% or more). If the residual elongation at break exceeds 100%, it is not preferable because fine pieces scraped or stretched from the surfaces of the polishing part and the polishing pad during polishing and surface renewal tend to block the pores. The “breaking residual elongation” means that a tensile test was performed at a test piece shape dumbbell shape No. 3 with a tensile speed of 500 mm / min and a test temperature of 80 ° C. according to JIS K 6251 “Tensile test method for vulcanized rubber”. When the test piece is ruptured, the elongation is the distance obtained by subtracting the distance between the marked lines before the test from the total distance from the marked line to the broken part of each of the broken and broken test pieces. In actual polishing, since heat is generated by sliding, the test is performed at a temperature of 80 ° C.

  The polishing pad composition may contain an uncrosslinked polymer in addition to the crosslinked PBD and other crosslinked polymers. Examples of uncrosslinked polymers include uncrosslinked 1,2-polybutadiene and uncrosslinked ethylene-vinyl acetate copolymers, as well as thermoplastic resins, elastomers, rubbers, curable resins, and the like mentioned as the other crosslinked polymers. Mention may be made of crosslinked polymers.

  The “water-soluble particles” are those that are detached from the water-insoluble matrix by contact with the slurry that is an aqueous dispersion, and are dispersed in the water-insoluble matrix. As the water-soluble particles are detached, pores are formed in the water-insoluble matrix. The desorption of water-soluble particles may be caused by dissolution by contact with water or the like contained in the slurry, and is caused by swelling and gelation containing this water or the like. Also good. Further, this dissolution or swelling may be caused not only by water but also by contact with an aqueous mixed medium containing an alcohol solvent such as methanol.

  In addition to forming pores, the water-soluble particles have the effect of increasing the indentation hardness of the polishing part and the polishing pad and reducing the amount of indentation of the object to be polished by the pressing. That is, for example, by containing water-soluble particles, the Shore D hardness of the polishing part and the polishing pad can be 35 or more (more preferably 50 to 90, still more preferably 60 to 85, usually 100 or less). When the Shore D hardness is 35 or more, the pressure that can be applied to the object to be polished can be increased, and the polishing rate can be improved accordingly. In addition, high polishing flatness can be obtained. Therefore, the water-soluble particles are particularly preferably solid bodies that can ensure sufficient indentation hardness of the polishing portion and the polishing pad.

  Although the kind of water-soluble compound which comprises water-soluble particle | grains is not specifically limited, For example, an organic type water-soluble compound and an inorganic type water-soluble compound can be mentioned. Organic water-soluble compounds include sugars (polysaccharides such as cyclodextrin, dextrin and starch, lactose, mannitol, etc.), celluloses (hydroxypropylcellulose, methylcellulose, etc.), proteins, polyvinyl alcohol, polyvinylpyrrolidone, polyacrylic acid , Polyacrylate, polyethylene oxide, water-soluble photosensitive resin, sulfonated polyisoprene, sulfonated polyisoprene copolymer, and the like. Furthermore, examples of the inorganic water-soluble compound include potassium acetate, potassium nitrate, potassium carbonate, potassium hydrogen carbonate, potassium chloride, potassium bromide, potassium phosphate, and magnesium nitrate. These water-soluble compounds can be used alone or in combination of two or more. Further, the water-soluble particles may be one kind of water-soluble particles made of a predetermined water-soluble compound, or two or more kinds of water-soluble particles made of different water-soluble compounds.

  The average particle diameter of the water-soluble particles is preferably 0.1 to 500 μm (more preferably 0.5 to 100 μm, still more preferably 1 to 50 μm). That is, the pore size is preferably 0.1 to 500 μm (more preferably 0.5 to 100 μm, still more preferably 1 to 50 μm). If the average particle size of the water-soluble particles is less than 0.1 μm, the size of the pores formed is smaller than the abrasive grains used, and therefore it tends to be difficult to obtain a polishing part and a polishing pad that can hold the slurry sufficiently. . On the other hand, if it exceeds 500 μm, the size of the pores formed becomes excessive, and the mechanical strength and polishing rate of the obtained polishing part and polishing pad tend to decrease.

  The content of the water-soluble particles is 10 to 90% by volume (more preferably 12 to 60% by volume, still more preferably) when the total of the water-insoluble matrix and the water-soluble particles is 100% by volume. Is preferably 15 to 45% by volume. When the content of the water-soluble particles is less than 10% by volume, pores may not be sufficiently formed in the obtained polishing portion and polishing pad, and the polishing rate may be reduced. On the other hand, when it contains water-soluble particles in excess of 90% by volume, it tends to be difficult to sufficiently prevent the water-soluble particles contained in the obtained polishing part and polishing pad from being swollen or dissolved in a chain. Further, it becomes difficult to maintain the hardness and mechanical strength of the polishing portion and the polishing pad at appropriate values.

  Further, it is preferable that the water-soluble particles are water-soluble only when they are exposed on the surface layer in the polishing portion and the polishing pad, absorb moisture inside the polishing portion and the polishing pad, and do not swell. For this reason, water-soluble particle | grains can be equipped with the outer shell which suppresses moisture absorption in at least one part of the outermost part. The outer shell may be physically adsorbed on the water-soluble particles, may be chemically bonded to the water-soluble particles, or may be in contact with the water-soluble particles by both. Examples of the material for forming such an outer shell include epoxy resin, polyimide, polyamide, polysilicate, and the like. Even if the outer shell is formed only on a part of the surface of the water-soluble particles, the above-mentioned effect can be sufficiently obtained.

  The water-insoluble matrix can contain a compatibilizing agent in order to control the affinity with the water-soluble particles and the dispersibility of the water-soluble particles in the water-insoluble matrix. Examples of compatibilizers include polymers modified with acid anhydride groups, carboxyl groups, hydroxyl groups, epoxy groups, oxazoline groups, amino groups, block copolymers, random copolymers, and various nonionic types. Surfactants, coupling agents and the like can be mentioned.

Furthermore, in the water-insoluble matrix and / or water-soluble particles, abrasive grains, oxidizing agents, alkali metal hydroxides, acids, salts that generate acids when used, pH regulators, conventionally contained in the slurry, 1 type (s) or 2 or more types, such as surfactant and an anti-scratch agent, can be contained. As a result, polishing can be performed by supplying only water during polishing.
Examples of the abrasive grains include particles made of silica, alumina, ceria, zirconia, titania and the like. These can use 1 type (s) or 2 or more types.
Examples of the oxidizing agent include hydrogen peroxide, peracetic acid, perbenzoic acid, organic peroxides such as tert-butyl hydroperoxide, permanganic acid compounds such as potassium permanganate, and dichromic acids such as potassium dichromate. Examples thereof include compounds, halogen acid compounds such as potassium iodate, nitric acid compounds such as nitric acid and iron nitrate, perhalogen acid compounds such as perchloric acid, persulfates such as ammonium persulfate, and heteropolyacids. Of these oxidizing agents, persulfates such as ammonium persulfate are particularly preferred in addition to hydrogen peroxide and organic peroxide, which are harmless to decomposition products. These can use 1 type (s) or 2 or more types.

Examples of the alkali metal hydroxide include sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide. These can use 1 type (s) or 2 or more types.
Examples of the acid include organic acids and inorganic acids. Among these, as the organic acid, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, isoprenesulfonic acid, gluconic acid, lactic acid, citric acid, tartaric acid, malic acid, glycolic acid, malonic acid, formic acid, oxalic acid, succinic acid, fumaric acid , Maleic acid and phthalic acid. Moreover, as an inorganic acid, nitric acid, hydrochloric acid, sulfuric acid, etc. are mentioned. These acids can be used alone or in combination of two or more.
Examples of the salt include alkali metal salts such as ammonium salts, sodium salts and potassium salts of the above acids, and alkaline earth metal salts such as calcium salts and magnesium salts. These can use 1 type (s) or 2 or more types.

  Examples of the surfactant include cationic, anionic and nonionic. Among these, examples of the cationic surfactant include aliphatic amine salts and aliphatic ammonium salts. Examples of the anionic surfactant include fatty acid soaps, carboxylates such as alkyl ether carboxylates, sulfonates such as alkylbenzene sulfonates, alkylnaphthalene sulfonates, α-olefin sulfonates, and higher alcohol sulfates. Examples include ester salts, sulfate salts such as alkyl ether sulfates, polyoxyethylene alkylphenyl ether sulfates, and phosphate ester salts such as alkyl phosphate esters. Furthermore, examples of the nonionic surfactant include ether types such as polyoxyethylene alkyl ether, ether ester types such as glycerol ester polyoxyethylene ether, and ester types such as polyethylene glycol fatty acid ester, glycerol ester and sorbitan ester. It is done. These can use 1 type (s) or 2 or more types.

  As said anti-scratch agent, biphenol, bipyridyl, 2-vinylpyridine and 4-vinylpyridine, salicylaldoxime, o-phenylenediamine and m-phenylenediamine, catechol, o-aminophenol, thiourea, N-alkyl group contained (Meth) acrylamide, N-aminoalkyl group-containing (meth) acrylamide, 7-hydroxy-5-methyl-1,3,4-triazaindolizine, 5-methyl-1H-benzotriazole, phthalazine, melamine and 3- Examples include amino-5,6-dimethyl-1,2,4-triazine. These can use 1 type (s) or 2 or more types.

  In addition, the water-insoluble matrix includes, in addition to the above-mentioned compatibilizer and various materials conventionally contained in the slurry, fillers, softeners, antioxidants, ultraviolet absorbers, antistatic agents, lubricants, plasticizers, etc. These various additives can be contained. Among these, as fillers, materials that improve rigidity such as calcium carbonate, magnesium carbonate, talc, clay, etc., and polishing effects such as silica, alumina, ceria, titania, zirconia, manganese dioxide, dimanganese trioxide, barium carbonate, etc. A material or the like may be used.

  The above-described polishing pad composition can be obtained by crosslinking an uncrosslinked polishing pad composition containing an uncrosslinked water-insoluble matrix and water-soluble particles dispersed in the uncrosslinked water-insoluble matrix. . Further, the uncrosslinked water-insoluble matrix contains uncrosslinked 1,2-polybutadiene and other uncrosslinked polymers except both uncrosslinked 1,2-polybutadiene and uncrosslinked ethylene-vinyl acetate copolymers, The uncrosslinked 1,2-polybutadiene is 10% by mass or more when the entire uncrosslinked water-insoluble matrix is 100% by mass, and each of the uncrosslinked 1,2-polybutadiene and other uncrosslinked polymers by the crosslinking treatment is used. It can be at least partially crosslinked.

  The non-crosslinked water-insoluble matrix is crosslinked to become the water-insoluble matrix. Uncrosslinked PBD is at least partially crosslinked during the crosslinking treatment. The cross-linked portion becomes the cross-linked PBD. When the entire uncrosslinked water-insoluble matrix is 100% by mass, the content of uncrosslinked PBD is 10% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or more. 30% by mass or more is particularly preferable. When the content of uncrosslinked PBD is less than 10% by mass, the amount of crosslinked PBD contained in the water-insoluble matrix after crosslinking may be less than 10% by mass, and the effect of containing crosslinked PBD is obtained. It may be difficult to obtain enough.

Other uncrosslinked polymers other than crosslinked PBD and crosslinked EVA are at least partially crosslinked during the crosslinking treatment to become the other crosslinked polymers. Examples of other uncrosslinked polymers include uncrosslinked products such as the aforementioned thermoplastic resins, elastomers, rubbers, and curable resins. Furthermore, other uncrosslinked polymers may be modified in the same manner as described above. These may be one kind or two or more kinds.
Among these uncrosslinked polymers, polyethylene resins, acrylonitrile-styrene-butadiene copolymers, styrene-butadiene-styrene copolymers, polyacrylic resins, vinyl ester resins, saturated polyester resins, polyamide resins and polyacetals. At least one of the uncrosslinked polymers of the resin is preferable. These may be one kind or two or more kinds. The reason why these are preferable is as described above.
The content of other uncrosslinked polymer is preferably 5% by mass or more, more preferably 10% by mass or more, and more preferably 20% by mass when the entire uncrosslinked water-insoluble matrix is 100% by mass. % Or more is particularly preferable. However, other uncrosslinked polymer is 90 mass% or less. In the polishing pad obtained when the content of the other uncrosslinked polymer is less than 5% by mass, the effects (1) and (2) may not be sufficiently exhibited.

  The preferred contents of the uncrosslinked PBD and other uncrosslinked polymers can be combined with each other. That is, for example, the uncrosslinked PBD is preferably 10 to 95% by mass and the other uncrosslinked polymer is preferably 5 to 90% by mass, the uncrosslinked PBD is 15 to 95% by mass and other uncrosslinked The polymer is more preferably 5 to 85% by mass, the uncrosslinked PBD is 20 to 90% by mass, and the other uncrosslinked polymer is particularly preferably 10 to 80% by mass, and the uncrosslinked PBD is It is particularly preferred that it is 30 to 80% by mass and the other uncrosslinked polymer is 20 to 70% by mass.

The crosslinking treatment is a treatment for crosslinking at least a part of the uncrosslinked PBD and other uncrosslinked polymers. In this crosslinking treatment, the uncrosslinked PBD and other uncrosslinked polymer may or may not be co-crosslinked. Further, the crosslinking of the uncrosslinked PBD and the crosslinking of the other uncrosslinked polymer may be performed simultaneously, and either one may be performed first and the other may be performed later. The method for crosslinking is not particularly limited, and can be performed by chemical crosslinking using organic peroxide, sulfur, sulfur compounds, etc., thermal crosslinking by heating, radiation crosslinking by electron beam irradiation, or the like. Among these, since the crosslinking efficiency is good, it is preferable to perform crosslinking using an organic peroxide.
Furthermore, in this crosslinking treatment, the amount of crosslinked PBD in the water-insoluble matrix after crosslinking treatment is preferably 10% by mass or more, and the degree of crosslinking of uncrosslinked PBD is preferably 5% or more. It is more preferably 10% or more, and particularly preferably 15% or more. Furthermore, the degree of crosslinking may be 100%.

  The method for obtaining the composition for an uncrosslinked polishing pad is not particularly limited. For example, a necessary material such as a predetermined organic material can be kneaded with a kneader or the like. A conventionally known kneader can be used. Examples thereof include kneaders such as rolls, kneaders, Banbury mixers, and extruders (single screw and multi screw). However, when kneading, it is kneaded by heating so that it can be easily kneaded, but it is preferable that the water-soluble compound is solid at this temperature. By being a solid, water-soluble particles can be dispersed at the preferred average particle diameter regardless of the compatibility with the uncrosslinked water-insoluble matrix. Therefore, it is preferable to select the type of water-soluble particles depending on the processing temperature of the uncrosslinked water-insoluble matrix used.

[2] Composition for Polishing Pad of the Present Invention The “water-insoluble matrix” is a parent phase constituting the polishing portion of the polishing pad and further the entire polishing pad. The water-insoluble matrix contains water-soluble particles dispersed therein.

  Although the content of the vinyl acetate unit in EVA is not particularly limited, it is usually 3% by mass or more. If it is less than 3% by mass, it may be difficult to sufficiently obtain the effect of reducing the temperature dependence of the longitudinal elastic modulus. The vinyl acetate unit content is preferably 5 to 50% by mass, more preferably 5 to 30% by mass, and particularly preferably 10 to 30% by mass. When the content of the vinyl acetate unit exceeds 50% by mass, overcrosslinking tends to occur, and it may be difficult to maintain sufficient toughness.

The water-insoluble matrix constituting the polishing pad composition of the present invention can have a residual elongation at break of 100% or less as in [1].
Furthermore, the amount of change in the longitudinal elastic modulus between the temperatures of 0 to 80 ° C. can be suppressed to 1000 MPa or less (further 800 MPa or less, particularly 600 MPa or less). Thereby, it is possible to prevent the polishing portion and the polishing pad from being excessively softened due to heat generated by sliding or the like particularly during polishing and dressing.
Further, when the temperature is 20 to 50 ° C., the amount of change in the longitudinal elastic modulus during the temperature difference of 10 ° C. can be suppressed to 500 MPa or less (further 400 MPa or less, particularly 200 MPa or less). As a result, the temperature dependence of the water-insoluble matrix changes more gradually, and it becomes easier to predict the degree of softening due to temperature and to control the polishing state.
This longitudinal elastic modulus is a value when measured with an initial load of 100 g, a maximum strain of 0.01%, and a frequency of 0.2 Hz, using a viscoelasticity measuring device or the like that can measure the longitudinal property ratio in the tensile mode. is there.

  As the “water-soluble particles”, the water-soluble particles in [1] can be applied as they are. Further, the water-insoluble matrix can contain a compatibilizing agent as in the above [1]. Further, in the water-insoluble matrix and / or the water-soluble particles, as in [1] above, abrasives, oxidizing agents, alkali metal hydroxides, acids, and acids that are conventionally contained in the slurry are generated. It can contain 1 type (s) or 2 or more types, such as a salt, a pH adjuster, surfactant, and an anti-scratch agent.

  The polishing pad composition according to [2] is obtained by crosslinking an uncrosslinked polishing pad composition containing an uncrosslinked water-insoluble matrix and water-soluble particles dispersed in the uncrosslinked water-insoluble matrix. Get. Further, the uncrosslinked water-insoluble matrix contains uncrosslinked PBD and uncrosslinked EVA, and the uncrosslinked PBD is 10% by mass or more when the entire uncrosslinked water-insoluble matrix is 100% by mass. PBD is 50% by mass or more when the total of uncrosslinked PBD and uncrosslinked EVA is 100% by mass, and at least a part of each of uncrosslinked 1,2-polybutadiene and uncrosslinked EVA is obtained by the crosslinking treatment. Cross-linked.

  The non-crosslinked water-insoluble matrix is crosslinked to become the water-insoluble matrix. Uncrosslinked PBD is at least partially crosslinked during the crosslinking treatment. The crosslinked part becomes a crosslinked PBD. When the entire uncrosslinked water-insoluble matrix is 100% by mass, the content of uncrosslinked PBD is 10% by mass or more, preferably 15% by mass or more, and more preferably 20% by mass or more. 30% by mass or more is particularly preferable. When the content of uncrosslinked PBD is less than 10% by mass, the amount of crosslinked PBD contained in the water-insoluble matrix after crosslinking may be less than 10% by mass, and the effect of containing crosslinked PBD is obtained. It may be difficult to obtain enough.

Uncrosslinked EVA is at least partially crosslinked during the crosslinking treatment. The cross-linked portion becomes cross-linked EVA. When the entire uncrosslinked water-insoluble matrix is 100% by mass, the content of uncrosslinked EVA is preferably 5% by mass or more, more preferably 10% by mass or more, and 20% by mass or more. Is particularly preferable, and particularly preferably 30% by mass or more. However, uncrosslinked EVA is contained in a range where the uncrosslinked PBD is 50% by mass or more when the total with the uncrosslinked PBD is 100% by mass. If the content of uncrosslinked EVA is less than 5% by mass, the crosslinked EVA contained in the water-insoluble matrix after crosslinking may be less than 5% by mass, and the effect of containing the crosslinked EVA is sufficiently obtained. It may be difficult to get caught.
Further, the content of the vinyl acetate unit in the uncrosslinked EVA is not particularly limited, but is preferably within the above-mentioned range for the same reason as the above-mentioned crosslinked EVA.

In addition, when the total amount of the water-insoluble matrix is 100% by mass, a preferable combination of the content of uncrosslinked PBD (X ₂ ) and the content of uncrosslinked EVA (Y ₂ ) is, for example, X ₂ of 10 It is preferable that Y ₂ exceeds 5% by mass and is 5% by mass or more and {X ₂ / (X ₂ + Y ₂ ) × 100}> 50, X ₂ exceeds 20% by mass and Y ₂ is 10% by mass or more. And more preferably {X ₂ / (X ₂ + Y ₂ ) × 100}> 50, X ₂ exceeds 30 mass%, Y ₂ is 15 mass% or more, and {X ₂ / (X ₂ + Y ₂ ) × 100}> 50, X ₂ is more than 40% by mass, Y ₂ is 20% by mass or more and {X ₂ / (X ₂ + Y ₂ ) × 100}> 50 It is particularly preferred that there is.

  Further, the uncrosslinked water-insoluble matrix can contain other polymers in addition to uncrosslinked PBD and uncrosslinked EVA. Other polymers include uncrosslinked polymers such as the thermoplastic resins, elastomers, rubbers, and curable resins listed in [1] above, and crosslinks obtained by crosslinking one of these uncrosslinked polymers. Examples thereof include a polymer and a crosslinked polymer obtained by co-crosslinking two or more of these uncrosslinked polymers. Among them, polyethylene resins, acrylonitrile-styrene-butadiene copolymers, styrene-butadiene-styrene copolymers, polyacrylic resins, vinyl ester resins, saturated polyester resins, polyamide resins and polyacetal resins At least one of these is preferred.

The crosslinking treatment is a treatment for crosslinking at least a part of uncrosslinked PBD and uncrosslinked EVA. In this crosslinking treatment, the uncrosslinked PBD and the uncrosslinked EVA may be co-crosslinked or may not be co-crosslinked. Further, the crosslinking of the uncrosslinked PBD and the crosslinking of the uncrosslinked EVA may be performed at the same time, either one may be performed first and the other may be performed later. The method for crosslinking is not particularly limited, and can be performed by chemical crosslinking using organic peroxide, sulfur, sulfur compounds, etc., thermal crosslinking by heating, radiation crosslinking by electron beam irradiation, or the like. Among these, since the crosslinking efficiency is good, it is preferable to perform crosslinking using an organic peroxide.
Further, in this crosslinking treatment, the amount of crosslinked PBD in the water-insoluble matrix after crosslinking treatment is 10% by mass or more, and the degree of crosslinking of uncrosslinked PBD and uncrosslinked EVA is 5% or more, respectively. Preferably, it is 10% or more, more preferably 15% or more. Furthermore, the degree of crosslinking of each may be 100%.

  The method for obtaining the composition for an uncrosslinked polishing pad is not particularly limited, and can be obtained in the same manner as in the above [1]. Furthermore, as in the above [1], it is preferable to select the type of water-soluble particles depending on the processing temperature of the uncrosslinked water-insoluble matrix to be used.

[3] Polishing pad The polishing pad of the present invention includes a polishing portion made of the polishing pad composition of the present invention. The “polishing part” is the whole or a part of the polishing pad and constitutes the whole or a part of the surface of the polishing pad used for polishing. This polishing portion is a portion that can exert a polishing effect on the object to be polished by supplying slurry, water, or the like. The size constituted by the polishing portion of the polishing pad is not particularly limited, but is at least 50% or more (more preferably 80% or more, more preferably 90% or more) of the surface of the polishing pad that is used for polishing. Preferably there is. If the portion constituted by the polishing portion is less than 50% of the surface, the effect of providing this polishing portion may not be sufficiently exhibited.

Moreover, the polishing pad of this invention can be provided with the part which has another function other than the grinding | polishing part which consists of a composition for polishing pads of this invention. Examples of the part having other functions include a window part for detecting an end point using an optical end point detection device. As a window part, for example, at a thickness of 2 mm, the transmittance of light of any wavelength between 100 and 300 nm is 0.1% or more (preferably 2% or more), or a wavelength of 100 to 300 nm. A material having an integrated transmittance of 0.1% or more (preferably 2% or more) in any wavelength region between 3000 nm can be used.
Furthermore, the polishing pad of this invention can also be equipped with the grinding | polishing part which consists of a composition for polishing pads other than the grinding | polishing part which consists of a composition for polishing pads of this invention.

Although the shape of this polishing pad is not particularly limited, it can be, for example, a disk shape, a belt shape, a roller shape, etc., and is preferably selected as appropriate according to the polishing apparatus. Further, the size of the polishing pad before use is not particularly limited, but for a disc-shaped polishing pad, for example, the diameter is 0.5 to 500 cm (further 1.0 to 250 cm, particularly 20 to 200 cm), and the thickness is 0.1 to 0.1 cm. It can be set to 100 mm (particularly 1 to 10 mm). Moreover, a groove | channel can be provided in the polishing surface of the polishing pad of this invention as needed. By providing the grooves, it is possible to exert the effect of spreading the slurry to every corner of the polishing surface and temporarily retaining the slurry. Furthermore, it becomes a path | route which discharges | emits wastes, such as grinding | polishing waste generated at the time of grinding | polishing efficiently. The shape of the groove is not particularly limited, and may be an annular shape, a spiral shape, a lattice shape, a dot pattern shape, or the like.
Moreover, the manufacturing method of the polishing pad of this invention is not specifically limited, It can shape | mold using a metal mold | die. Further, after forming into a sheet shape, it can be obtained by punching into a predetermined shape. Furthermore, after shaping into a block shape, it can be obtained by slicing into a predetermined shape.

[4] Multi-layer type polishing pad A multi-layer type polishing pad comprising the polishing pad of the present invention and a support layer disposed on the back side of this polishing pad (the side opposite to the surface used for polishing). Obtainable.
The support layer is a layer that supports the polishing pad on the back surface side. The characteristics of the support layer are not particularly limited, but are preferably softer than the polishing pad. By providing a softer support layer, even when the thickness of the polishing pad is thin (for example, 0.5 mm or less), the polishing pad is lifted during polishing or the surface of the polishing pad is curved. It can prevent and can polish stably. The hardness of the support layer is preferably 90% or less (more preferably 80% or less, particularly 70% or less, usually 10% or more) of the hardness of the polishing pad. Furthermore, the Shore D hardness is preferably 70 or less (more preferably 60 or less, still more preferably 50 or less, usually 1 or more).

  The support layer may be a porous body (foam) or a non-porous body. Furthermore, the planar shape is not particularly limited, and may be the same as or different from the polishing pad. The planar shape of the support layer can be, for example, a circle or a polygon (such as a quadrangle). Moreover, although the thickness is not specifically limited, for example, it can be 0.1-5 mm (more preferably 0.5-2 mm). However, for example, when the polishing pad is provided with a window for detecting the end point using an optical end point detection device, a window portion similar to that of the polishing pad or the like so as not to block light transmitted through the window portion. The same window part can be provided, or it can also be set as the notched shape which does not have a window part but light passes.

The material constituting the support layer is not particularly limited, but it is preferable to use an organic material because it can be easily molded into a predetermined shape and properties and can be provided with appropriate elasticity. As the organic material, various polymers constituting the water-insoluble matrix in the polishing pad can be applied. However, the organic material constituting the support layer may be a crosslinked polymer or an uncrosslinked polymer.
In addition, the support layer may include only one layer or may include two or more layers. Moreover, this support layer and polishing pad may be laminated | stacked in direct contact, and may be laminated | stacked through another layer. Furthermore, the support layer may be bonded to the polishing pad or other layers with an adhesive, an adhesive (such as an adhesive tape) or the like, or may be integrally bonded by being partially melted.

  These polishing pads and multilayer polishing pads of the present invention are provided with an elastic recovery force by containing the crosslinked PBD. In addition, excellent moldability and wear resistance are imparted by containing other cross-linked polymers. Therefore, even in CMP, metal wiring such as STI, Al and Cu, which requires particularly high flatness, via plugs using Al, Cu and W, interlayer insulating films (oxide film, Low-k, BPSG, etc.), It is suitable for polishing a nitride film (TaN, TiN, etc.), polysilicon, bare silicon, etc.

Hereinafter, the present invention will be described specifically by experiment examples.
[1] a polishing pad manufacturing Experiment Example 1 (Example)
70 parts by mass of uncrosslinked 1,2-polybutadiene (manufactured by JSR Corporation, product name “JSR RB830”) and 30 parts by mass of uncrosslinked ethylene-vinyl acetate copolymer (manufactured by Tosoh Corporation, product name “Ultrasen 630”) And 40 parts by mass of water-soluble particles β-cyclodextrin (Yokohama International Bio-Laboratory Co., Ltd., product name “Dexipal β-100”, average particle size 20 μm) are biaxially extruded at 160 ° C. It knead | mixed using the machine. Thereafter, 1.0 part by mass of an organic peroxide (Nippon Yushi Co., Ltd., product name “Park Mill D40”) was added and further kneaded. This kneaded product was held in a mold controlled at 170 ° C. for 18 minutes for crosslinking treatment to obtain a polishing pad having a diameter of 60 cm and a thickness of 3 mm. In the obtained polishing pad, the content of 1,2-polybutadiene in the water-insoluble matrix by pyrolysis gas chromatography (hereinafter simply referred to as “Py-GC”) was 72 mass%. Furthermore, the volume ratio of the water-soluble particles when the entire polishing pad was 100% by volume was about 21% by volume (the same applies when the total of the water-insoluble matrix and the water-soluble particles was 100% by volume).

Experimental Example 2 (Example)
55 parts by mass of uncrosslinked 1,2-polybutadiene (product name “JSR RB830” manufactured by JSR Corporation) and 45 units of uncrosslinked ethylene-vinyl acetate copolymer (product name “Ultrasen 630” manufactured by Tosoh Corporation) A polishing pad with a diameter of 60 cm and a thickness of 3 mm was obtained in the same manner as in Example 1 except that the mass part was changed. In the obtained polishing pad, the content of 1,2-polybutadiene in the water-insoluble matrix by Py-GC was 58% by mass. Furthermore, the volume ratio of the water-soluble particles was about 21% by volume in the same manner as Experiment Example 1.

Experimental Example 3 (Reference Example)
70 parts by mass of uncrosslinked 1,2-polybutadiene (product name “JSR RB830” manufactured by JSR Co., Ltd.) is used instead of an uncrosslinked ethylene-vinyl acetate copolymer. YF30 ") except that the 30 parts by mass were kneaded by experiments the same manner as in example 1, a twin-screw extruder. Thereafter, an organic peroxide (NOF Corporation, product name "Percumyl D40") Similarly diameter 60cm a except for using 1.0 part by weight amount as Experiment Example 1, a polishing pad of thickness 3mm Obtained. In the obtained polishing pad, the content of 1,2-polybutadiene in the water-insoluble matrix by Py-GC was 73% by mass. Furthermore, the volume ratio of the water-soluble particles was about 21% by volume in the same manner as Experiment Example 1.

Comparative Example 1
100 parts by mass of uncrosslinked 1,2-polybutadiene (product name “JSR RB830”, manufactured by JSR Corporation) and β-cyclodextrin (product of Yokohama International Bio-Laboratory Co., Ltd., product name “Dexipearl β-100” manufactured by JSR Corporation) And 40 parts by mass of an average particle diameter of 20 μm) were kneaded using a biaxial extruder adjusted to 160 ° C. Thereafter, 0.3 parts by mass of an organic peroxide (Nippon Yushi Co., Ltd., product name “Park Mill D40”) was added and further kneaded. This kneaded product was held in a mold adjusted to 170 ° C. for 18 minutes for crosslinking treatment to obtain a polishing pad having a diameter of 60 cm and a thickness of 3 mm. In the obtained polishing pad, the content of 1,2-polybutadiene in the water-insoluble matrix by Py-GC was 96% by mass. Furthermore, the volume ratio of the water-soluble particles was about 21% by volume in the same manner as Experiment Example 1.

[2] was produced, respectively 20 pieces of the polishing pad in the same manner as the evaluation of moldability experiments Examples 1-3 and Comparative Example 1. However, two different demolding methods were used when demolding. On the other hand, one end of the molded product was grasped with a jig and transported as it was to the mounting table beside the molding machine. On the other hand, a thin metal plate was inserted under the molded product, and this metal plate was gripped and conveyed as it was to the mounting table beside the molding machine so that the molded product would not bend. Ten polishing pads were manufactured for each mold removal method. As a result, the obtained polishing pad was observed, the polishing pads in which cracks or cracks were visually recognized were counted, and the ratio of cracks or cracks to the total number produced was calculated. The results are shown in Table 1.

[3] Test pieces were cut out from the polishing pad obtained in the abrasion resistance evaluation experiments Examples 1-3 and Comparative Example 1 were measured wear volume with DIN abrasion tester according to JIS K 6264. The results are also shown in Table 1.

[4] Evaluation of the temperature dependence of the longitudinal elastic modulus Using a solid viscoelasticity measuring device (Rheometric Scientific, model “RSAII”), a strip test of 2.5 mm × 1.0 mm Using the piece, the longitudinal elastic modulus was measured in the tensile mode under the conditions of -20 to 100 ° C., initial load 100 g, maximum strain 0.01%, frequency 0.2 Hz. And the variation | change_quantity of the longitudinal elastic modulus between 0-80 degreeC was computed, and it described together in Table 1.

From the results of Table 1, it can be seen that in Comparative Example 1 in which the uncrosslinked water-insoluble matrix is composed only of uncrosslinked PBD, cracks occur with a probability of 30% during demolding, and it is preferable to use an auxiliary plate. Moreover, in the obtained polishing pad, it turns out that the variation | change_quantity and wear volume of a longitudinal elastic modulus are large compared with an Example.
In contrast, in Experiment Examples 1 to 3, not produce any cracking without using the auxiliary plate during demolding, it found to be excellent in moldability compared to the comparative example. Further, the amount of change in the longitudinal elastic modulus is as small as 600 to 800 MPa. In particular experiment example 1 and experiment example contains a crosslinking EVA 2, it can be seen that the variation of the longitudinal elastic modulus becomes 25 to 38% smaller than in Comparative Example 1. Further, the wear volume is 200 to 350 cm ³ , which is 30 to 60% smaller than that of Comparative Example 1. Therefore, it can be seen that the polishing pad containing another crosslinked polymer in addition to the crosslinked PBD is excellent in moldability and wear resistance. It can also be seen that the amount of change in the longitudinal elastic modulus is reduced particularly when the other crosslinked polymer is crosslinked EVA.

Claims (5)

In a polishing pad composition comprising a water-insoluble matrix and water-soluble particles dispersed in the water-insoluble matrix, the water-insoluble matrix comprises crosslinked 1,2-polybutadiene, crosslinked 1,2-polybutadiene and crosslinked ethylene. -Other cross-linked polymer excluding both vinyl acetate copolymer, and the cross-linked 1,2-polybutadiene is 10% by mass or more when the total amount of the water-insoluble matrix is 100% by mass. A polishing pad composition. In a polishing pad composition comprising a water-insoluble matrix and water-soluble particles dispersed in the water-insoluble matrix, the water-insoluble matrix comprises a crosslinked 1,2-polybutadiene and a crosslinked ethylene-vinyl acetate copolymer. The crosslinked 1,2-polybutadiene is 10% by mass or more when the total amount of the water-insoluble matrix is 100% by mass, and the crosslinked 1,2-polybutadiene comprises the crosslinked 1,2-polybutadiene and the crosslinked 1,2-polybutadiene. A polishing pad composition characterized by being 50% by mass or more when the total of the cross-linked ethylene-vinyl acetate copolymer is 100% by mass. The polishing pad composition according to claim 2, wherein the water-insoluble matrix further contains another crosslinked polymer excluding both the crosslinked 1,2-polybutadiene and the crosslinked ethylene-vinyl acetate copolymer. The polishing according to claim 1 or 3, wherein the other crosslinked polymer is at least one of a crosslinked polyethylene polymer, a crosslinked acrylonitrile-styrene-butadiene copolymer, and a crosslinked styrene-butadiene-styrene copolymer. Pad composition. A polishing pad comprising a polishing portion comprising the polishing pad composition according to any one of claims 1 to 4.