TW202100598A - Polishing pad and method for producing polished article - Google Patents

Abstract

The purpose of the invention is to provide a polishing pad which is capable of reducing the occurrence of scratches; and a method for producing a polished article. The polishing pad of the invention comprises a polyurethane sheet as a polishing layer, wherein the polyurethane sheet in a dry state has a ratio of a minimum loss elastic modulus (E”min) to a maximum loss elastic modulus (E”max) of 0.60 to 1.00, in the loss elastic modulus (E”) within a range of 40 to 80^o C, as determined by a dynamic viscoelasticity measurement at a frequency of 1.6 Hz at a temperature of 20 to 100^o C.

Description

Manufacturing method of polishing pad and polishing processed object

The present invention relates to a manufacturing method of a polishing pad and a polishing product.

Materials for semiconductor devices, electronic parts, etc., especially Si substrates (silicon wafers), GaAs (gallium arsenide) substrates, glass or LCD (liquid crystal display) substrates, etc. The surface (processed surface) of thin substrates (grinding objects) , The use of polishing slurry for chemical mechanical polishing using polishing pads.

The polishing pads used in these polishing processes are for the purpose of reducing pits, and it is known to use polishing pads having a polishing layer with an E'ratio of about 1 to 3.6 at 30°C to 90°C (Patent Document 1), or based on Flattening performance and low defect performance is the purpose. It is known to use a polishing pad with a porosity of 0.1% by volume and a polymer material as the polishing layer. The polymer is 385~750 l/ at 40°C and 1rad/sec The KEL energy loss coefficient of Pa and the elastic modulus E'of 100~400MPa at 40°C and 1rad/sec (Patent Document 2). [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Special Publication No. 2004-507076 [Patent Document 2] JP 2005-136400 A

[The problem to be solved by the invention]

However, when the polishing pads described in Patent Documents 1 and 2 are used, the surface quality of the object to be polished cannot be said to be high, and it is known that, for example, scratches are caused.

The present invention was completed in view of the above-mentioned problems, and its object is to provide a method for manufacturing a polishing pad and a polishing product that can reduce scratches. [Means to solve the problem]

As a result of active research to solve the above-mentioned problems, the inventors found that the above-mentioned problems can be solved by suppressing the fluctuation of the loss elastic modulus E" in a specific temperature range below a certain level, and completed the present invention.

That is, the present invention is as follows. [1] A polishing pad equipped with a polyurethane sheet as a polishing layer. The polyurethane sheet is subjected to dynamic viscoelasticity measurement at a frequency of 1.6 Hz and a temperature of 20 to 100°C in a dry state. In the loss elastic modulus E" at 40~80℃, the ratio of the smallest loss elastic modulus E"min to the maximum loss elastic modulus E"max is 0.60~1.00. [2] Such as [1] The polishing pad, wherein in the aforementioned dynamic viscoelasticity measurement of the polyurethane sheet, the loss modulus of elasticity E” (80) at 80°C is relative to the loss modulus of elasticity E” (40) at 40°C The ratio is 0.60~1.50. [3] For polishing pads such as [1] or [2], the aforementioned loss modulus E"min is 1.40×10 ⁷ Pa or more. [4] Such as the polishing pad of any one of [1]~[3], where the temperature representing the aforementioned loss of elastic modulus E"max is in the range of 55~75℃. [5] Such as [1]~[4 ] The polishing pad according to any one of ], wherein the polyurethane sheet comprises a polyurethane resin and hollow fine particles dispersed in the polyurethane resin. [6] One of a polishing process The manufacturing method includes: in the presence of a polishing slurry, the polishing pad is used to polish an object to be polished using any one of [1] to [5] to obtain a polishing processed object. [Effects of the Invention]

According to the present invention, it is possible to provide a method for manufacturing a polishing pad and a polishing object that can reduce scratches.

Hereinafter, an embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail, but the present invention is not limited to this, and various changes can be made without departing from the gist.

[Grinding pad] The polishing pad of this embodiment is equipped with a polyurethane sheet as a polishing layer. The polyurethane sheet is in a dry state, and the dynamic viscoelasticity is measured at a frequency of 1.6 Hz and 20 to 100°C. In the loss elastic modulus E" at 40~80℃, the ratio of the smallest loss elastic modulus E"min to the maximum loss elastic modulus E"max is 0.60~1.00.

(Loss modulus of elasticity E") Loss elastic modulus E" is an indicator of the viscosity displayed by the measurement object under the measurement conditions. In this embodiment, by suppressing the dynamic viscosity of the polishing layer in the dynamic process of polishing to a specific range, Makes the contact state with the object to be polished (workpiece) better during polishing, and further suppresses the occurrence of scratches by suppressing the stubborn pressing of polishing debris generated by polishing. More specifically, under polishing conditions, By reducing the fluctuation of the loss elastic modulus E" (viscosity component), the occurrence of scratches can be suppressed.

Under the polishing conditions, the polishing layer is brought into contact with the object to be polished by a specific polishing action at a specific temperature. At this time, due to the frictional heat of the grinding, there is a possibility that the temperature in the grinding surface may increase locally. Therefore, in this embodiment, in the dynamic viscoelasticity measurement of the polishing layer at the frequency of 1.6 Hz and the condition of 20~100°C, the loss elastic modulus E" at 40~80°C is the smallest loss elastic modulus E" The ratio of min to the maximum loss elastic modulus E"max is specified in a specific range.

The ratio of loss elastic modulus E”min to loss elastic modulus E”max, that is, loss elastic modulus E”min/loss elastic modulus E”max is 0.60~1.00, preferably 0.65~1.00, more preferably 0.70 ~1.00, more preferably 0.75~1.00, still more preferably 0.80~1.00, particularly preferably 0.85~1.00. By making the ratio of the loss elastic modulus E”min to the loss elastic modulus E”max within the above-mentioned range, in the temperature range of 40~80℃, the loss elastic modulus E” has little fluctuation, and the loss elastic modulus E" shows certain. Thereby, even if the temperature is increased, the viscosity can be exerted and the occurrence of scratches can be suppressed.

The loss elastic modulus E"min is preferably 1.40×10 ⁷ Pa or more, more preferably 1.50×10 ⁷ Pa or more, still more preferably 1.80×10 ⁷ Pa or more, and particularly preferably 2.00×10 ⁷ Pa or more. The upper limit of the loss elastic modulus E"min is not particularly limited, but it is preferably 3.00×10 ⁷ Pa or less, and more preferably 2.80×10 ⁷ Pa or less. By making the loss elastic modulus E"min fall within the above range, there is a tendency to suppress the occurrence of scratches by exhibiting viscosity.

The temperature showing the loss elastic modulus E”min is preferably 60~80℃, more preferably 70~80℃, and still more preferably 75~80℃. Even if the temperature showing the loss elastic modulus E”min is on the higher temperature side , Also by satisfying the ratio of loss modulus of elasticity E"min to loss modulus of elasticity E"max, there is a tendency to suppress the occurrence of scratches.

In addition, the loss elastic modulus E"max is preferably 1.90×10 ⁷ Pa to 4.00×10 ⁷ Pa, more preferably 2.00×10 ⁷ Pa to 3.50×10 ⁷ Pa, and still more preferably 2.10×10 ⁷ Pa to 2.90 ×10 ⁷ Pa. By making the loss elastic modulus E"min fall within the above range, there is a tendency to suppress the occurrence of scratches by exhibiting viscosity and increase the polishing rate.

As one aspect, the temperature at which the loss elastic modulus E"max is displayed is preferably 40 to 65°C, more preferably 40 to 55°C, and still more preferably 40 to 45°C. By making the display loss elastic modulus E" The temperature of max is on the lower temperature side, and the parts other than the part where the temperature rises locally have a tendency to exhibit viscosity and inhibit the occurrence of scratches.

As another aspect, the temperature of the display loss elastic modulus E"max is preferably 55~75°C, more preferably 55~70°C, and still more preferably 55~65°C. By making the display loss elastic modulus E" When the temperature of max falls within the above range, during polishing, the viscous component will be exerted in the part where the temperature rises locally, and there is a tendency to suppress the occurrence of scratches.

In addition, the polyurethane sheet of the present embodiment preferably has a loss modulus E" that also decreases at high temperatures. More specifically, the loss modulus E" at 80°C under the above-mentioned dynamic viscoelasticity measurement conditions (80) The ratio of the loss elastic modulus E"(40) relative to 40℃, that is, the loss elastic modulus E”(80)/loss elastic modulus E”(40) is preferably 0.60~1.50, more Preferably it is 0.65 ~ 1.50, more preferably 0.70 ~ 1.30, particularly preferably 0.80 ~ 1.10. By making the loss elastic modulus E "(80) at 80 ℃ relative to the loss elastic modulus E "( The ratio of 40) is within the above range. Compared with the low temperature (40°C), the loss elastic modulus E" at high temperature (80°C) has a smaller change, which tends to suppress the occurrence of scratches.

The dynamic viscoelasticity measurement of this embodiment can be carried out according to common methods, but the dynamic viscoelasticity measurement in the dry state is used in a constant temperature and humidity tank with a temperature of 23°C (±2°C) and a relative humidity of 50% (±5%) The polished layer kept for 40 hours is used as a sample, and the sample is usually measured in an atmospheric environment (dry state). As a dynamic viscoelasticity measuring device that can perform these measurements, for example, RSA III of TA Instruments, etc. can be illustrated. Regarding other conditions. It is not particularly limited, but can be measured under the conditions described in the examples.

(Polyurethane sheet) As the polishing pad having the above characteristics, a polyurethane sheet is used. The polyurethane resin constituting the polyurethane sheet is not particularly limited, but examples include polyester-based polyurethane resins, polyether-based polyurethane resins, and poly Carbonate-based polyurethane resin. These can be used individually by 1 type or in combination of 2 or more types.

The polyurethane resin is not particularly limited as long as it is a reaction product of a urethane prepolymer and a hardener, and various conventional ones can be applied. Here, the urethane prepolymer is not particularly limited, but examples are, for example, an adduct of hexamethylene diisocyanate and hexanetriol; a combination of 2,4-toluene diisocyanate and phytocatechol Adducts; adducts of toluene diisocyanate and hexanetriol; adducts of toluene diisocyanate and trimethylolpropane; adducts of xylene diisocyanate and trimethylolpropane; hexamethylene diisocyanate The adduct of isocyanate and trimethylolpropane; and the adduct of isocyanuric acid and hexamethylene diisocyanate. In addition to these, isocyanate group-containing compounds prepared by the reaction of a polyisocyanate compound and a polyol, or a variety of commercially available urethane prepolymers can also be used. A urethane prepolymer may be used individually by 1 type, and may use 2 or more types together.

The polyisocyanate compound used as the isocyanate group-containing compound is not particularly limited if it has two or more isocyanate groups in the molecule. For example, as a diisocyanate compound having two isocyanate groups in the molecule, m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-toluene diisocyanate (2,6-TDI), 2,4 -Toluene diisocyanate (2,4-TDI), naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), 4,4'-methylene-bis(cyclohexyl) Isocyanate) (hydrogenated MDI), 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 3,3'-dimethoxydiphenylmethane-4,4'-diisocyanate, bis Toluene-1,4-diisocyanate, 4,4'-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1 ,2-Diisocyanate, cyclohexylene-1,2-diisocyanate, cyclohexylene-1,4-diisocyanate, p-phenylene diisocyanate, xylene-1,4-diisocyanate, ethylene diisocyanate Isocyanates, etc. The polyisocyanate compound is preferably a diisocyanate, of which 2,4-TDI, 2,6-TDI, and MDI are more preferred, and 2,4-TDI, 2,6-TDI are particularly preferred. These polyisocyanate compounds can be used alone or in combination with a plurality of polyisocyanate compounds.

The polyisocyanate preferably contains 2,4-TDI and/or 2,6-TDI, and more preferably contains 2,4-TDI and 2,6-TDI. It is even better to include only 2,4-TDI and 2,6-TDI. The better quality of 2,6-TDI for 2,4-TDI is 100:0~50:50, more preferably 90:10~60:40, more preferably 90:10~70:30, and even better It's 80:20.

Polyol compounds used as compounds containing isocyanate groups can be exemplified by glycol compounds such as ethylene glycol, diethylene glycol (DEG), butanediol, triol compounds; polypropylene glycol (PPG), poly(oxytetral Polyether polyol compounds such as methylene) glycol (PTMG); polyester polyol compounds such as the reactant of ethylene glycol and adipic acid or the reactant of butanediol and adipic acid; polycarbonate polyol Alcohol compounds, polycaprolactone polyol compounds, etc. Furthermore, trifunctional propylene glycol to which ethylene oxide has been added can also be used. Among them, PTMG is preferred, and PTMG and DEG are preferably used in combination. The number average molecular weight (Mn) of PTMG is preferably 500-2000, more preferably 600-1300, and still more preferably 650-1000. The number average molecular weight can be determined by Gel Permeation Chromatography (GPC). In addition, the measurement of the number average molecular weight of the polyol compound from a polyurethane resin can be estimated by GPC after decomposition by a common method such as amine decomposition. The polyol compound may be used alone or in combination with a plurality of polyol compounds.

The NCO equivalent of the urethane prepolymer is preferably 300-700, more preferably 350-600, and still more preferably 400-500. In addition, the NCO equivalent is based on "(parts by mass of polyisocyanate compound + parts by mass of polyol compound)/[(number of functional groups per molecule of polyisocyanate compound x parts by mass of polyisocyanate compound/molecular weight of polyisocyanate compound)-( The number of functional groups per molecule of polyol compound×mass part of polyol compound/molecular weight of polyol compound)]", which represents the value of the molecular weight of the NCO group per equivalent of the urethane prepolymer.

The curing agent is not particularly limited, but for example, ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, 3 ,3'-Dichloro-4,4'-diaminodiphenylmethane (MOCA), 4-methyl-2,6-bis(methylthio)-1,3-phenylenediamine, 2-methyl Group-4,6-bis(methylthio)-1,3-phenylenediamine, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 2,2-bis[3-(iso Propylamino)-4-hydroxyphenyl]propane, 2,2-bis[3-(1-methylpropylamino)-4-hydroxyphenyl]propane, 2,2-bis[3-(1-methyl Pentylamino)-4-hydroxyphenyl)propane, 2,2-bis(3,5-diamino-4-hydroxyphenyl)propane, 2,6-diamino-4-methylphenol, three Polyamine compounds such as methyl ethylene bis-4-amino benzoate and polybutylene oxide-di-p-amino benzoate; ethylene glycol, propylene glycol, diethylene glycol, three Ethylene glycol, tetraethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-butanediol, 3 -Methyl-1,2-butanediol, 1,2-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 2,3-dimethyltriethylene glycol, tetraethylene glycol Methyl glycol, 3-methyl-4,3-pentanediol, 3-methyl-4,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1 ,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, 2,5-hexanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, glycerol, Polyol compounds such as trimethylolpropane, trimethylolethane, trimethylolmethane, poly(oxytetramethylene)glycerol, polyethylene glycol, and polypropylene glycol. Furthermore, the polyamine compound may have a hydroxyl group. Examples of these amine compounds include 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, and di-2 -Hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, etc.

As the polyamine compound, a diamine compound is preferred, and 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA) is particularly preferred. Examples of MOCA include PANDEX E (manufactured by DIC Corporation), IHARACUAMINE MT (manufactured by KUMIAL Chemical Corporation), and the like. Furthermore, as the polyol compound, among them, polypropylene glycol is preferred, polypropylene glycol having a number average molecular weight of 1000 to 3000 is more preferred, and polypropylene glycol having a number average molecular weight of 1500 to 2500 is more preferred. The curing agent may be used alone or in combination of two or more kinds.

With respect to 100 parts by mass of the urethane prepolymer, the hardener is preferably added in 10-60 parts by mass, more preferably 20-50 parts by mass, and still more preferably 20-40 parts by mass.

By the molecular weight (degree of polymerization) of the urethane prepolymer or the combination of the urethane prepolymer and the hardener, the value of the loss elastic modulus E"max and the loss elastic modulus E"min can be adjusted The value, the temperature of the loss elastic modulus E”max, the temperature of the loss elastic modulus E”min, the loss elastic modulus E” (40) and the loss elastic modulus E” (80). Based on these viewpoints, as an example, it is particularly exemplified to adjust the ratio of the active hydrogen groups (amine groups and hydroxyl groups) present in the hardener with respect to the isocyanate groups present at the end of the isocyanate group-containing compound as the urethane prepolymer. Equivalence ratio method. More specifically, in the formation of the polyurethane sheet, the equivalent ratio (R value) of the active hydrogen group of the curing agent to the isocyanate group of the isocyanate group-containing compound is preferably 0.70 to 1.20, more preferably 0.75~1.10, and more preferably 0.80~1.00. By adjusting the equivalent ratio of the active hydrogen group of the curing agent to the isocyanate group of the isocyanate group-containing compound within the above range, the value of the elastic modulus E"max of the obtained polyurethane sheet can be reduced, The value of the number E”min, the temperature of the loss elastic modulus E”max, the temperature of the loss elastic modulus E”min, the loss elastic modulus E” (40) and the loss elastic modulus E” (80) are adjusted in this implementation The specific range of the form.

In addition, the polyurethane sheet is preferably a foamed polyurethane sheet having bubbles. In addition, the bubbles of the foamed polyurethane sheet are determined according to their state, and are classified into independent bubbles in which multiple bubbles exist independently and continuous bubbles in which multiple bubbles are connected by connecting holes. Among them, the polyurethane sheet of this embodiment preferably has closed cells, and more preferably comprises a polyurethane resin and a polyurethane resin dispersed in hollow fine particles in the polyurethane resin. Ester flakes. By using hollow particles, it is easy to adjust the value of elastic modulus E"max, the value of loss elastic modulus E"min, the temperature of loss elastic modulus E"max, the temperature of loss elastic modulus E"min, and the loss of elasticity. The tendency of modulus E” (40) and loss of elastic modulus E” (80).

The polyurethane sheet with closed cells can be formed by using hollow particles with a shell and a hollow inside. Commercially available hollow microparticles can be used, or those obtained by synthesis by common methods can also be used. The shell material of the hollow fine particles is not particularly limited, but for example, polyvinyl alcohol, polyvinylpyrrolidone, poly(meth)acrylic acid, polyacrylamide, polyethylene glycol, polyhydroxy ether acrylate, horse Acrylic acid copolymer, polyethylene oxide, polyurethane, poly(meth)acrylonitrile, polyvinylidene chloride, polyvinyl chloride, and organosiloxane resins and monomer combinations that constitute these resins 2 More than one kind of copolymer. In addition, the commercially available hollow microparticles are not limited to the following examples, such as Expancel series (trade name manufactured by AkzoNobel), Matsumoto Microsphere (trade name manufactured by Matsumoto Oil Co., Ltd.) and the like.

The shape of the hollow fine particles in the polyurethane sheet is not particularly limited, and the nitrogen may be spherical or slightly spherical, for example. The average particle diameter of the hollow fine particles is not particularly limited, but is preferably 5 to 200 μm, more preferably 5 to 80 μm. By using these hollow particles, it is also possible to adjust the value of elastic modulus E"max, the value of loss elastic modulus E"min, the temperature of loss elastic modulus E"max, the temperature of loss elastic modulus E"min, Loss elastic modulus E” (40) and loss elastic modulus E” (80). In addition, the average particle size can be measured by a laser diffraction particle size distribution measuring device (for example, SPECTRIS Co., Ltd., MasterSizer-2000).

With respect to 100 parts by mass of the urethane prepolymer, the hollow fine particles are preferably added at 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, and still more preferably 1 to 3 parts by mass.

In addition to the above components, within the range that does not impair the effect of the present invention, the foaming agent used in the past may be used in combination with the hollow fine particles, and non-reactive gas may be blown into the components in the following mixing step . Examples of the foaming agent include water or a foaming agent mainly composed of a hydrocarbon having 5 or 6 carbon atoms. Examples of the hydrocarbon include chain hydrocarbons such as n-pentane and n-hexane, or alicyclic hydrocarbons such as cyclopentane and cyclohexane. Furthermore, in addition to the aforementioned components, conventional foaming agents, flame retardants, colorants, plasticizers, etc. may be added.

The manufacturing method of the polyurethane sheet is not particularly limited. For example, for example, the polyurethane prepolymer is reacted with a hardener to form a polyurethane resin block, and the obtained polyurethane A method of cutting out thin pieces from a resin block. Through the mixing step, the urethane prepolymer and the hardening agent are fed into the mixer, stirred and mixed. In addition, in the case of using hollow fine particles, by mixing a urethane prepolymer and a hardener with the hollow fine particles, a polyurethane resin block containing the hollow fine particles can be obtained. The mixing order is not particularly limited, but it is preferable to mix the urethane prepolymer and the hollow fine particles in advance, and then supply the hardener in the mixer. In this way, a mixed liquid for polyurethane resin blocks was prepared. The mixing step is carried out in a state of heating to a temperature that can ensure the fluidity of the above-mentioned components.

For example, in a solution of urethane prepolymer (such as an isocyanate group-containing compound) heated to 30~90°C containing hollow particles, put the hardener into a mixer with a temperature-adjustable jacket Inside, stir at 30~130℃. The mixed liquid can also be matured in a tank with a jacket attached to a mixer as needed. The mixing time is appropriately adjusted according to the number of teeth or rotations of the mixer, the clearance rate, etc., for example, 0.1 to 60 seconds.

First, in the mixing step, the mixing ratio of the urethane prepolymer and the hardener is adjusted so that the above-mentioned R value is preferably 0.70 to 1.20, more preferably 0.75 to 1.10, and even more preferably 0.80 to 1.00.

In the molding step, the polyurethane resin block mixture prepared in the mixing step is poured into a mold frame preheated to 30-100°C, and heated at 100-150°C for about 10 minutes to 5 hours to harden , Thereby forming a polyurethane resin block. At this time, a polyurethane resin is formed by the reaction between the urethane prepolymer and the hardener, and the air bubbles and/or hollow particles are dispersed in the aforementioned polyurethane resin. The mixture hardens. Thereby, a polyurethane resin block containing a large number of substantially spherical bubbles is formed.

The polyurethane resin block obtained by the aforementioned forming step is then sliced into flakes to form polyurethane flakes. By slicing, openings are provided on the surface of the sheet. At this time, in order to form openings on the surface of the polishing layer with excellent wear resistance and not easily clogged, it can also be aged at 30 to 150°C for about 1 to 24 hours.

The thus obtained polishing layer with polyurethane flakes is then attached with a double-sided tape on the side opposite to the polishing surface of the polishing layer, and cut into a specific shape, preferably into a circular plate shape, to complete the implementation The shape of the polishing pad. The double-sided tape is not particularly limited, and it can be arbitrarily selected and used from double-sided tapes known in the art.

In addition, the polishing pad of this embodiment may have a single-layer structure composed of only the polishing layer, or may be a composite obtained by laminating other layers (lower layer, support layer) on the surface of the polishing layer opposite to the polishing surface. Floor. The characteristics of the other layers are not particularly limited. If a layer softer than the polishing layer (lower A hardness or D hardness) is attached to the opposite side of the polishing layer, the polishing flatness will be improved. On the other hand, if a layer harder (higher A hardness or D hardness) than the polishing layer is attached to the surface on the opposite side of the polishing layer, the polishing rate will be further increased.

In the case of a multi-layer structure, double-sided tapes or adhesives are used for the plural layers, and they can be fixed while pressing as needed. The double-sided tapes or adhesives used at this time are not particularly limited, and can be selected and used arbitrarily from double-sided tapes or adhesives known in the art.

Furthermore, the polishing pad of this embodiment may be used on the surface and/or back surface of the polishing layer to perform grinding treatment, groove processing, embossing processing, or hole processing (pressing processing) on the surface as needed. /Or the adhesive layer and the polishing layer are bonded together, and a light transmitting portion may be provided. The method of grinding treatment is not particularly limited, and grinding can be done by conventional methods. Specifically, for example, grinding particles with sandpaper. The shape of the groove processing and the embossing processing is not particularly limited, and examples thereof include a lattice type, a concentric circle type, and a radial type.

[Manufacturing Method of Polished Products] The method of manufacturing a polished product of the present embodiment includes a polishing step of polishing the object to be polished using the above-mentioned polishing pad in the presence of a polishing slurry to obtain a polished product. The grinding step may be one-time grinding (rough grinding), fine grinding, or a combination of both. Among them, the polishing pad of this embodiment is preferably used for chemical mechanical polishing. Hereinafter, chemical mechanical polishing is used as an example to describe the method of manufacturing the polished product of this embodiment, but the method of manufacturing the polished product of this embodiment is not limited to the following.

In this manufacturing method, while supplying the polishing slurry, the holding platen presses the object to be polished against the side of the polishing pad, while the holding platen and the polishing platen are relatively rotated, so that the processed surface of the object is The polishing pad is polished by chemical mechanical polishing (CMP). The holding platen and the grinding platen can rotate in the same direction at different rotation speeds, or in different directions. In addition, during the polishing process, the object to be polished may be polished while moving (rotating) inside the frame.

The polishing slurry may contain chemical components such as water, oxidizing agents represented by hydrogen peroxide, additives, abrasive particles (abrasive particles; such as SiC, SiO ₂ , Al ₂ O ₃ , CeO ₂ ) etc.

In addition, the object to be polished is not particularly limited, but examples include materials such as semiconductor devices and electronic parts, especially Si substrates (silicon wafers), SiC (silicon carbide) substrates, GaAs (gallium arsenide) substrates, Thin substrates (objects to be polished) such as glass or LCD (liquid crystal display) substrates. Among them, the method of manufacturing a polished product of this embodiment can be preferably used as a method of manufacturing a semiconductor device in which an oxide layer, a metal layer such as copper, or the like is formed. [Example]

Hereinafter, the present invention will be explained in more detail using examples and comparative examples. The present invention is not limited at all by the following examples.

[Example 1] In the reaction of 2,4-toluene diisocyanate (TDI), poly(oxytetramethylene) glycol (PTMG) and diethylene glycol (DEG), the NCO equivalent of 420g/Eq urethane precursor To 100 parts of the polymer, add 3.0 parts of expanded hollow fine particles (average particle size 20μm) with the mixed shell part made of acrylonitrile-vinylidene chloride copolymer and isobutane gas in the shell to obtain amino formic acid Ester prepolymer mixture. The obtained urethane prepolymer mixture was fed into the first tank and kept at 80°C. In addition, in addition to the first tank, 3,3'-dichloro-4,4'-diaminodiphenylmethane ( 27.8 parts of methylene bis-o-chloroaniline) (MOCA) and 9.2 parts of polypropylene glycol were heated and melted at 120° C. and mixed to obtain a hardener melt. In addition, the equivalent ratio (R value) of active hydrogen groups to isocyanate groups was 0.90.

Next, each liquid in the first liquid tank and the second liquid tank is injected from each injection port of a mixer equipped with two injection ports, and a mixed solution is obtained by stirring and mixing. In addition, at this time, the mixing ratio was adjusted so that the R value representing the equivalent ratio of the amino group and the hydroxyl group present in the curing agent to the isocyanate group present in the terminal of the urethane prepolymer became 0.90.

The obtained mixed liquid is injection molded into a mold frame preheated at 100°C, and cured at 110°C for 30 minutes. The formed block-shaped molded product was drawn out from the mold frame, and cured in an oven at 130°C for a second time for 2 hours to obtain a urethane resin block. The obtained urethane resin block was allowed to cool to 25°C, and then heated in an oven at 120°C for 5 hours, and then sliced into 1.3 mm thick to obtain a foamed polyurethane sheet. A double-sided tape was attached to the back of the obtained polyurethane sheet and used as a polishing pad.

[Example 2] In the reaction of 2,4-toluene diisocyanate (TDI), poly(oxytetramethylene) glycol (PTMG) and diethylene glycol (DEG), the NCO equivalent of 460g/Eq urethane precursor To 100 parts of the polymer, 3.0 parts of hollow fine particles were added and mixed as in Example 1 to obtain a urethane prepolymer mixture. Furthermore, as the hardening agent, 25.5 parts of MOCA having an active hydrogen equivalent of 134 g/Eq and 8.5 parts of polypropylene glycol were heated and melted to obtain a hardening agent melt. Using the urethane prepolymer mixture and the hardener melt, it was produced in the same manner as in Example 1 to obtain a polishing pad. In addition, the equivalent ratio (R value) of the active hydrogen group equivalent to the isocyanate group equivalent was 0.90.

[Example 3] In the reaction of 2,4-toluene diisocyanate (TDI), poly(oxytetramethylene) glycol (PTMG) and diethylene glycol (DEG), the NCO equivalent of 455g/Eq urethane precursor To 100 parts of the polymer, add 2.7 parts of unexpanded hollow fine particles (average particle size 8.5μm) containing isobutane gas in the mixed shell part made of acrylonitrile-vinylidene chloride copolymer to obtain the amino group Formate prepolymer mixture. The obtained urethane prepolymer mixture was fed into the first tank and kept at 80°C. In addition, in addition to the first tank, 3,3'-dichloro-4,4'-diaminodiphenylmethane ( 25.8 parts of methylene bis-o-chloroaniline) (MOCA) were heated and melted at 120°C and mixed to obtain a hardening agent melt. In addition, the equivalent ratio (R value) of active hydrogen groups to isocyanate groups was 0.90.

[Comparative Example 1] As Comparative Example 1, an IC1000 mat manufactured by NITTA HAAS was prepared.

[Dynamic viscoelasticity measurement] Based on the following conditions, the dynamic viscoelasticity measurement of the polyurethane sheet was performed. First of all, a polyurethane sheet kept in a dry state for 40 hours in a constant temperature and humidity tank with a temperature of 23°C (±2°C) and a relative humidity of 50% (±5%) was used as a sample. The polyurethane flakes obtained under normal atmospheric environment (dry state) were used as samples for dynamic viscoelasticity measurement. As the dynamic viscoelasticity measuring device, RSA III (manufactured by TA Instruments) was used. The dynamic viscoelasticity measurement results of the examples and comparative examples are shown in FIG. 1. (Measurement conditions) Measuring device: RSA III (manufactured by TA Instruments) Sample: Length 4cm×Width 0.5cm×Thickness 0.125cm Test length: 1cm Sample pretreatment: keep for 40 hours under the temperature 23℃/relative humidity 50% Test mode: stretch Frequency: 1.6Hz (10rad/sec) Temperature range: 20~100℃ Heating rate: 5℃/min Deformation range: 0.10% Initial load: 148g Measurement interval: 1 point/℃

[Noodle quality confirmation test] A polishing pad was installed at a specific position of the polishing device via a double-sided adhesive tape with an acrylic adhesive, and the Cu film substrate was polished under the following conditions. (Grinding conditions) Grinding machine: F-REX300X (manufactured by Ebara Manufacturing Co., Ltd.) Disc: A188 (manufactured by 3M) Rotation number: (pressure plate) 70rpm, (top surface) 71rpm Grinding pressure: 3.5psi Abrasive temperature: 20℃ Amount of abrasive spray: 200ml/min Abrasive: PLANERLITE7000 (manufactured by Fuzimi Co., Ltd.) Object to be polished: Cu film substrate Grinding time: 60 seconds Pad brake: 35N for 10 minutes Adjustment: Ex-situ, 35N, 4 scan

Regarding the 10th to 50th pieces of the polished object after the above-mentioned polishing process, visually confirm the polished surface with a Review SEM of eDR5210 (manufactured by KLA Tencor) that is greater than 155nm of linear polishing scratches (scratches) and the polished surface For point-like abrasive scratches (micro-scratches) larger than 155nm, the average value is obtained. Based on the confirmation result of the scratch, the noodle quality was evaluated.

[產業上之可利用性]

[Industrial availability]

The polishing pad of the present invention can be used for polishing optical materials, semiconductor devices, glass substrates for hard disks, etc., and can be particularly used as a device for polishing semiconductor wafers with oxide layers, copper and other metal layers. The polishing pad has industrial applicability.

[Figure 1] is a graph showing the results of dynamic viscoelasticity measurement in Examples 1 to 3 and Comparative Example 1.

Claims (6)

A polishing pad provided with a polyurethane sheet as a polishing layer, In the dynamic viscoelasticity measurement of the polyurethane sheet in a dry state at a frequency of 1.6 Hz and 20~100°C, the loss of elastic modulus E" at 40~80°C is the smallest loss of elasticity The ratio of the modulus E"min to the maximum loss elastic modulus E"max is 0.60~1.00. The polishing pad according to claim 1, wherein in the aforementioned dynamic viscoelasticity measurement of the polyurethane sheet, the loss elastic modulus E" (80) at 80°C is relative to the loss elastic modulus E" at 40°C. The ratio of (40) is 0.60~ 1.50. Such as the polishing pad of claim 1 or 2, wherein the aforementioned loss elastic modulus E"min is 1.40×10 ⁷ Pa or more. Such as the polishing pad of claim 1 or 2, wherein the temperature indicating the aforementioned loss of elastic modulus E"max is in the range of 55~75℃. The polishing pad according to claim 1 or 2, wherein the polyurethane sheet comprises a polyurethane resin and hollow fine particles dispersed in the polyurethane resin. A method for manufacturing a polished product, comprising: in the presence of a polishing slurry, a polishing pad according to any one of claims 1 to 5 is used to polish the polished object to obtain the polished product.

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