Polishing pad, method for manufacturing a polishing pad, and method for polishing the surface of an optical material or semiconductor material.

Abstract

To provide a polishing pad which is excellent in step dissolution performance and can suppress dishing and defect, and provide a method for manufacturing the polishing pad, and a method for polishing a surface of an optical material or a semiconductor material using the polishing pad.SOLUTION: A polishing pad has a polishing layer containing a polyurethane resin, wherein the polyurethane resin is a cured product of a curable resin composition containing an isocyanate terminal urethane prepolymer and a curing agent; the isocyanate terminal urethane prepolymer is a reaction product of a polyol component and a polyisocyanate component; the polyol component contains a high molecular weight polyol; the high molecular weight polyol contains polyol having a carbonate group in the molecule and a number average molecular weight of Mna; and a number average molecular weight of the isocyanate terminal urethane prepolymer is Mna or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polishing pad, a method for manufacturing a polishing pad, and a method for polishing the surface of an optical material or a semiconductor material. The polishing pad of the present invention is used for polishing optical materials, semiconductor wafers, semiconductor devices, hard disk substrates, etc., and is particularly suitable for polishing devices on which an oxide layer, a metal layer, etc., is formed on a semiconductor wafer. [Background technology]

[0002] Optical materials, semiconductor wafers, hard disk substrates, LCD glass substrates, and semiconductor devices require extremely precise flatness. Hard polishing pads are commonly used to polish the surfaces of these various materials, especially the surfaces of semiconductor devices, to a flat surface. Currently, the abrasive layer in many hard polishing pads typically uses a hard polyurethane material obtained by curing an isocyanate-terminated urethane prepolymer, which is a reaction product of an isocyanate component such as tolylene diisocyanate (TDI) and a polyol component containing a high molecular weight polyol such as polytetramethylene ether glycol (PTMG), with a curing agent such as 3,3'-dichloro-4,4'-diaminodiphenylmethane. The high molecular weight polyol that forms the isocyanate-terminated urethane prepolymer forms the soft segment of the polyurethane, and PTMG has traditionally been commonly used as the high molecular weight polyol due to its ease of handling and appropriate rubber elasticity.

[0003] In the polishing of semiconductor devices, the miniaturization and increasing density of integrated circuits in recent years have led to a demand for more stringent levels of performance in eliminating steps on the surface of the workpiece and suppressing defects such as scratches. If the performance in eliminating steps on the surface of the workpiece is insufficient, a phenomenon called dishing, in which the cross-section of the wiring becomes concave in a dish-like shape, mainly in wide wiring patterns, is likely to occur, and the local flatness of the workpiece surface deteriorates.

[0004] Conventional polishing pads using PTMG as a high molecular weight polyol are sometimes insufficient in terms of step-leveling performance and defect suppression, and studies are being conducted on using polyols other than PTMG as high molecular weight polyols.

[0005] Patent Document 1 discloses that a polishing pad formed using polypropylene glycol (PPG) as the high molecular weight polyol for the isocyanate-terminated urethane prepolymer exhibits excellent step-leveling performance and low defect occurrence. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-157415 [Overview of the project] [Problems that the invention aims to solve]

[0007] However, if the entire amount of high molecular weight polyol is PPG, as in the polishing pad described in Patent Document 1, the wear resistance of the polishing layer may be poor, resulting in a shorter lifespan for the polishing pad. Furthermore, if the entire amount of high molecular weight polyol is PPG, as in the polishing pad described in Patent Document 1, the resulting isocyanate-terminated urethane prepolymer tends to soften. To prevent this, it becomes necessary to adjust the equivalent amounts of the polyol component and the polyisocyanate component during the production of the isocyanate-terminated urethane prepolymer.

[0008] As described above, there is a need for a polishing pad that excels in eliminating steps, suppresses dishing, and suppresses defects.

[0009] This invention has been made in view of the above-mentioned problems, and aims to provide a polishing pad that has excellent step-leveling performance, can suppress dishing, and can suppress defects. [Means for solving the problem]

[0010] The present inventors, through diligent research to solve the above problems, have found that the above problems can be solved by using a polyol having a carbonate group in its molecule as the high molecular weight polyol component for forming the isocyanate-terminated urethane prepolymer, and by setting the weight-average molecular weight of the isocyanate-terminated urethane prepolymer to 2000 or less, and have completed the present invention. Specific embodiments of the present invention are as follows.

[0011] [1] A polishing pad having a polishing layer containing polyurethane resin, The polyurethane resin is a cured product of a curable resin composition comprising an isocyanate-terminated urethane prepolymer and a curing agent, and the isocyanate-terminated urethane prepolymer is a reaction product of a polyol component and a polyisocyanate component. The polyol component includes a high molecular weight polyol. The aforementioned high molecular weight polyol includes a polyol having a carbonate group in its molecule and a number-average molecular weight of Mna. The polishing pad wherein the number-average molecular weight of the isocyanate-terminated urethane prepolymer is Mna or less. [2] The polishing pad according to [1], wherein, in the molecular weight distribution of the isocyanate-terminated urethane prepolymer measured by gel permeation chromatography (GPC) on a polyethylene glycol / polyethylene oxide (PEG / PEO) basis, the molecular weight of the peak top of the peak located in the molecular weight region of 700 to 10000 is Mna+1000 or less. [3] The polishing pad according to [1] or [2], wherein the polyol having a carbonate group in the molecule has a number average molecular weight Mna of 500 to 2500. [4] The polishing pad according to any one of [1] to [3], wherein the number average molecular weight of the isocyanate-terminated urethane prepolymer is 3500 or less. [5] The polishing pad according to [4], wherein the number average molecular weight of the isocyanate-terminated urethane prepolymer is 2000 or less. [6] The polishing pad according to any one of [1] to [5], wherein the polyol having a carbonate group in the molecule contains a structural unit derived from polytetramethylene ether glycol. [7] The polishing pad according to any one of claims [1] to [6], wherein the polyol having a carbonate group in the molecule contains a polyether polycarbonate diol represented by the following formula (I): [Chemical formula] (In the above formula (I), R 1 is a divalent hydrocarbon group having 2 to 10 carbon atoms, and a plurality of R 1 may be the same or different, n is 2 to 30, m is 0.1 to 20.). [8] The polishing pad according to [7], wherein R 1 in the formula (I) is at least one selected from the group consisting of ethylene, isopropylene, and n-butylene. [9] The polishing pad according to any one of [1] to [8], wherein the high molecular weight polyol further contains a polyether polyol.

[10] The polishing pad according to any one of [1] to [9], wherein the polyisocyanate component contains tolylene diisocyanate.

[11] The polishing pad according to any one of [1] to

[10] , wherein the curing agent contains 3,3'-dichloro-4,4'-diaminodiphenylmethane.

[12] The polishing pad according to any one of [1] to

[11] , wherein the curable resin composition further contains micro hollow spheres.

[13] A method for manufacturing the polishing pad according to any one of [1] to

[12] , the method including a step of forming the polishing layer.

[14] A method for polishing the surface of an optical material or a semiconductor material, the method including a step of polishing the surface of an optical material or a semiconductor material using the polishing pad according to any one of [1] to

[12] .

[0012] (Definition) In this application, when expressing a numerical range using "X to Y", the range shall include the numerical values X and Y at both ends.

Advantages of the Invention

[0013] The polishing pad of the present invention is excellent in step elimination performance, can suppress dishing, and can suppress defects.

Brief Description of the Drawings

[0014] [Figure 1] (a) to (c) of FIG. 1 are schematic diagrams showing the state in which steps are eliminated by polishing. [Figure 2] FIG. 2 is a graph showing the relationship between the polishing amount and the step. [Figure 3] FIG. 3 is a graph showing the results of GPC measurement of the isocyanate-terminated urethane prepolymer used in Examples 1 and 2 and Comparative Examples 1 and 2. [Figure 4] (a) and (b) of FIG. 4 are graphs showing the evaluation results of the step elimination performance of the polishing pads of Examples 1 and 2 and Comparative Examples 1 and 2. [Figure 5] (c) and (d) of FIG. 5 are graphs showing the evaluation results of the step elimination performance of the polishing pads of Examples 1 and 2 and Comparative Examples 1 and 2. [Figure 6] FIG. 6 is a graph showing the evaluation results of the defects of the polishing pads of Examples 1 and 2 and Comparative Examples 1 and 2.

Embodiments for Carrying Out the Invention

[0015] (Function) The inventors diligently studied the relationship between the type of polyol component forming the isocyanate-terminated urethane prepolymer, the molecular weight distribution of the isocyanate-terminated urethane prepolymer, and the step-reducing performance and defect. As a result, they unexpectedly discovered that by using a polyol having a carbonate group in its molecule and a number-average molecular weight of Mna as the high molecular weight polyol component forming the isocyanate-terminated urethane prepolymer, and by setting the number-average molecular weight of the isocyanate-terminated urethane prepolymer to Mna or less, it is possible to obtain a polishing pad that has excellent step-reducing performance, can suppress dishing, and can suppress defect. The detailed reasons for obtaining these properties are not clear, but they are presumed to be as follows.

[0016] Polyols containing carbonate groups within their molecules are thought to have lower crystallinity compared to PTMG due to the presence of carbonate groups, and the isocyanate-terminated urethane prepolymers formed from such polyols are also thought to have lower crystallinity. When the crystallinity of the isocyanate-terminated urethane prepolymer that forms the polishing layer is low, it is thought that the debris generated during polishing will not aggregate easily, making it less likely for large clumps to form. Furthermore, when the number-average molecular weight of the prepolymer is Mna or less, the content of the ultra-high molecular weight components described later is low, and the prepolymer has excellent uniformity, so it is thought that the properties of the carbonate group can be expressed more significantly. As a result, it is presumed that the step-leveling performance of the workpiece will be improved, dishing will be suppressed, and defects will be suppressed.

[0017] (Performance in eliminating uneven surfaces) In semiconductor manufacturing processes, the damascene process is used to produce metal (Cu) wiring. In this process, grooves are cut into an insulating film on a silicon wafer, metal is embedded in these grooves by sputtering or other methods, and excess metal is removed by chemical mechanical polishing (CMP) to form metal wiring. To eliminate the physical or chemical stress that occurs between the insulating film and the metal, the insulating film is usually coated with a barrier metal before the metal is embedded.

[0018] Schematic diagrams of experiments evaluating the step-elimination performance are shown in Figures 1(a) to 1(c). Figure 1(a) shows the state before polishing begins. As shown in Figure 1(a), when a metal film (Cu film) 20 is embedded in the grooves of the insulating film (oxide film) 10, a step (difference in thickness between the part with grooves and the part without grooves) 40 is created between the part with grooves and the part without grooves, depending on the width of the grooves present beneath the metal film 20. In Figure 1(a), the thickness 30 of the metal film 20 in the part without grooves is 8000 Å, and the step 40 is 3500 Å. Figure 1(b) shows the state after polishing amount is 2000 Å, and the step 41 is 2000 Å. Figure 1(c) shows the state after polishing amount is 6000 Å, and the step 42 is almost 0.

[0019] In this application, "step reduction performance" refers to the ability to reduce the steps (unevenness) of a pattern wafer when polished. Figure 2 shows a graph illustrating the relationship between the amount of polishing (Å) and the step height (Å) when using polishing pad A (dotted line), which has high step height reduction performance, and polishing pad B (solid line), which has relatively low step height reduction performance, on a workpiece in the state shown in Figure 1(a). The points (a) to (c) for polishing pad A in Figure 2 correspond to the states (a) to (c) in Figure 1, respectively. In Figure 2, although there is no difference in step height between the dotted line and the solid line before polishing begins (point (a)), as polishing progresses and the amount of polishing reaches 2000 Å, it is shown that polishing pad A (dotted line) has a smaller step height than polishing pad B (solid line) (point (b)). Furthermore, as can be seen from Figure 2, the step height is reduced faster with polishing pad A (dotted line) than with polishing pad B (solid line) (point (c)). From the results in Figure 2, it can be said that polishing pad A, shown by the dotted line, has relatively higher step height reduction performance than polishing pad B, shown by the solid line.

[0020] (Defect) Furthermore, in this application, "defect" refers to a general term for defects including "particles," which are fine particles remaining on the surface of the workpiece; "pad debris," which are remnants of the polishing layer on the surface of the workpiece; and "scratches," which are scratches on the surface of the workpiece. Defect performance refers to the performance of reducing these "defects."

[0021] The following describes the polishing pad of this application, a method for manufacturing the polishing pad, and a method for polishing the surface of an optical material or semiconductor material.

[0022] 1. Polishing pad, method for manufacturing a polishing pad In some embodiments of the present application, the polishing pad has a polishing layer comprising a polyurethane resin, wherein the polyurethane resin is a cured product of a curable resin composition comprising an isocyanate-terminated urethane prepolymer and a curing agent, and the isocyanate-terminated urethane prepolymer is a reaction product of a polyol component and a polyisocyanate component. The polyol component includes a high molecular weight polyol, and the high molecular weight polyol includes a polyol having a carbonate group in its molecule and a number-average molecular weight of Mna. The number-average molecular weight of the isocyanate-terminated urethane prepolymer is Mna or less.

[0023] (Polishing pad) The polishing pad of this application has a polishing layer containing polyurethane resin. The polishing layer is positioned in direct contact with the material to be polished, and the rest of the polishing pad may be made of a material for supporting the polishing pad, such as an elastic material like rubber. Depending on the rigidity of the polishing pad, the polishing layer itself can function as the polishing pad.

[0024] The polishing pad of this invention does not differ significantly in shape from a general polishing pad, except that it can suppress dishing and defects in the workpiece, and can be used in the same way as a general polishing pad. For example, it can be used to polish by pressing the polishing layer against the workpiece while rotating the polishing pad, or by pressing the workpiece against the polishing layer while rotating the workpiece.

[0025] The polishing pad of this invention can be manufactured by generally known manufacturing methods such as mold molding and slab molding. First, a block of polyurethane is formed by these manufacturing methods, the block is made into a sheet by slicing or the like, an polishing layer formed from polyurethane resin is molded, and then it is bonded to a support or the like. Alternatively, the polishing layer can be molded directly onto the support.

[0026] More specifically, the polishing layer is fitted with double-sided tape on the side opposite to the polishing surface, cut to a predetermined shape, and becomes a polishing pad. There are no particular restrictions on the double-sided tape, and any double-sided tape known in the art can be arbitrarily selected and used. Furthermore, the polishing pad may be a single-layer structure consisting only of the polishing layer, or it may be a multi-layer structure in which other layers (underlayer, support layer) are attached to the side opposite to the polishing surface of the polishing layer.

[0027] The polished layer is formed by preparing a curable resin composition containing an isocyanate-terminated urethane prepolymer and a curing agent, and then curing the curable resin composition. The polishing layer can be made from foamed polyurethane resin, and foaming can be achieved by dispersing a foaming agent containing minute hollow spheres in the polyurethane resin. In this case, a curable resin composition containing an isocyanate-terminated urethane prepolymer, a curing agent, and a foaming agent can be prepared, and the polishing layer can be molded by foaming and curing the curable resin composition. The curable resin composition can also be a two-component composition prepared by mixing, for example, liquid A containing an isocyanate-terminated urethane prepolymer and liquid B containing a curing agent component. Other components may be added to either liquid A or liquid B, but if problems occur, the composition can be further divided into multiple liquids and mixed to form three or more liquids.

[0028] (Isocyanate-terminated urethane prepolymer) In some embodiments, the isocyanate-terminated urethane prepolymer is a product obtained by reacting a polyol component with a polyisocyanate component, wherein the polyol component includes a high molecular weight polyol, and the high molecular weight polyol includes a polyol having a carbonate group in its molecule.

[0029] The number-average molecular weight of the isocyanate-terminated urethane prepolymer is less than or equal to Mna, where Mna is the number-average molecular weight of the polyol having a carbonate group in the molecule. For example, if Mna is 1000, the number-average molecular weight is 1000 or less, preferably 950 or less, and most preferably 900 or less. By including a high molecular weight polyol with a number-average molecular weight of Mna and having a carbonate group in the molecule, and having a number-average molecular weight of Mna or less for the isocyanate-terminated urethane prepolymer, a polishing pad can be obtained that has excellent step-eliminating performance, can suppress dishing, and can suppress defects.

[0030] The means for making the number-average molecular weight of the isocyanate-terminated urethane prepolymer less than or equal to Mna are not particularly limited, but can be achieved, for example, by reducing the proportion of ultra-high molecular weight components formed by adding 3 or more polyisocyanate components to 2 or more high molecular weight polyol molecules, which are included in the peak in the molecular weight region of 700 to 10000 described later, or by increasing the proportion of components included in the peak in the molecular weight region of 400 to 700 described later. The means for reducing the proportion of the ultra-high molecular weight components to the entire isocyanate-terminated urethane prepolymer are not particularly limited, but can be said to be by using high molecular weight polyols that are as uniform as possible (with a small molecular weight distribution) or by making the reaction conditions such as temperature and pressure mild to suppress the chain reaction generation of ultra-high molecular weight components. While not particularly limited, a means of increasing the proportion of components contained in the peaks in the molecular weight range of 400 to 700 relative to the entire isocyanate-terminated urethane prepolymer is to adjust the reaction conditions to increase the proportion of components formed by the addition of two polyisocyanate components to both ends of one low molecular weight polyol molecule.

[0031] The number-average molecular weight of the isocyanate-terminated urethane prepolymer can be 500 to 2500. The upper limit of the number-average molecular weight of the isocyanate-terminated urethane prepolymer can be 3500 or less, 2500 or less, 2000 or less, 1500 or less, or 1000 or less, and the lower limit can be 500 or more, 600 or more, 700 or more, or 800 or more. These upper and lower limits can be combined in any way.

[0032] The weight-average molecular weight of the isocyanate-terminated urethane prepolymer is preferably 500 to 2500, preferably 1000 to 2000, and most preferably 1300 to 1600.

[0033] In some embodiments, the content of the component contained in the peak in the molecular weight range of 200 to 400 relative to the entire isocyanate-terminated urethane prepolymer is preferably 10% or less, more preferably 8.5% or less, and most preferably 7% or less. The lower limit of the content of the component contained in the peak can be 1% or more, 3% or more, or 5% or more, and these upper and lower limits can be arbitrarily combined. Furthermore, it is preferable that the peak in the molecular weight range of 200 to 400 is an unreacted polyisocyanate component.

[0034] In some embodiments, the content of the component contained in the peak in the molecular weight range of 400 to 700 relative to the entire isocyanate-terminated urethane prepolymer is preferably 5 to 40%, more preferably 10 to 35%, and most preferably 15 to 30%. Furthermore, it is preferable that the peak in the molecular weight range of 400 to 700 originates from a component formed by the addition of two polyisocyanate components to both ends of one low molecular weight polyol molecule.

[0035] In some embodiments, the upper limit of the content of the component contained in the peak in the molecular weight range of 700 to 10000 relative to the entire isocyanate-terminated urethane prepolymer is preferably 80% or less, more preferably 78% or less, and most preferably 76% or less. The lower limit of the content of the component contained in the peak can be 50% or more, 60% or more, or 65% or more, and these upper and lower limits can be arbitrarily combined. Furthermore, it is preferable that the peak in the molecular weight range of 700 to 10000 originates from a component formed by adding two polyisocyanate components to both ends of one high molecular weight polyol molecule, and from an ultramolecular-weight component formed by adding three or more polyisocyanate components to two or more high molecular weight polyol molecules.

[0036] The peaks in the molecular weight range of 700 to 10000 preferably contain ultra-high molecular weight components formed by the addition of two or more high molecular weight polyol molecules and three or more polyisocyanate components (when the number-average molecular weight Mna of the high molecular weight polyol is 1000, the molecular weight of the ultra-high molecular weight components will be 2000 or more). In this application, a low amount of the above ultra-high molecular weight components is preferred. Since the peaks in the molecular weight range of 700 to 10000 are broad, it is relatively difficult to determine the content ratio of the ultra-high molecular weight components. However, the content ratio of the ultra-high molecular weight components can be estimated from the number-average molecular weight of the entire isocyanate-terminated prepolymer or the peak-top molecular weight of the peaks in the molecular weight range of 700 to 10000. The smaller the number-average molecular weight of the entire isocyanate-terminated prepolymer and / or the peak-top molecular weight of the peaks in the molecular weight range of 700 to 10000, the lower the estimated content ratio of the above ultra-high molecular weight components. In some embodiments, the peak top molecular weight of the peaks in the molecular weight range of 700 to 10000 is preferably Mna + 1000 or less (where Mna is the number-average molecular weight of the polyol having a carbonate group in the molecule). When Mna is 1000, the peak top molecular weight is preferably 2000 or less, more preferably 1850 or less, and most preferably 1700 or less. When Mna is 2000, the peak top molecular weight is preferably 3000 or less, more preferably 2850 or less, and most preferably 2700 or less. Furthermore, the lower limit of the peak top molecular weight of the peaks in the molecular weight range of 700 to 10000 can be 1000 or more, 1300 or more, or 1500 or more, and the upper limit can be 3000 or less, 2850 or less, 2700 or less, 2000 or less, 1850 or less, or 1700 or less. These lower and upper limits can be combined arbitrarily. Due to the low content of the aforementioned ultra-high molecular weight components, the prepolymer exhibits excellent uniformity, which is thought to allow the properties of the carbonate group to be expressed more prominently. As a result, it is presumed that the step-leveling performance of the workpiece will be improved, dishing will be suppressed, and defects will be reduced.

[0037] The number-average molecular weight and weight-average molecular weight of the isocyanate-terminated urethane prepolymer described above, the content of the components contained in each peak, and the number-average molecular weight, weight-average molecular weight, and molecular weight of the peak top of each peak can be calculated by preparing a sample and performing measurements according to the procedures described in (Sample preparation method), (Measurement method), and (Measurement conditions) of (Gel permeation chromatography (GPC) measurement of isocyanate-terminated urethane prepolymer) in the [Examples] section below.

[0038] The NCO equivalent (g / eq) of the isocyanate-terminated urethane prepolymer is preferably less than 600, more preferably between 350 and 550, and most preferably between 400 and 500. By having the NCO equivalent (g / eq) within the above numerical range, a polishing pad with appropriate polishing performance can be obtained.

[0039] (Polyol component) The polyols having carbonate groups within their molecules, as described above, are a type of high molecular weight polyol.

[0040] Polyols having carbonate groups in their molecules preferably contain structural units derived from polytetramethylene ether glycol. The number-average molecular weight of the structural units derived from polytetramethylene ether glycol is preferably 100 to 1500, more preferably 150 to 1000, and most preferably 200 to 850.

[0041] Polyols having a carbonate group in their molecule preferably include a polyether polycarbonate diol represented by the following formula (I), and more preferably consist of a polyether polycarbonate diol represented by the following formula (I).

[0042] [ka] (In the above formula (I), R 1 It is a divalent hydrocarbon group having 2 to 10 carbon atoms, and multiple R 1They may be the same or different. n is from 2 to 30, m is from 1 to 20.).

[0043] In the above formula (I) representing the polyether polycarbonate diol, R 1 is a divalent hydrocarbon group having 2 to 10 carbon atoms, and R 1 Examples include ethylene, n-propylene, isopropylene, n-butylene, isobutylene, 1,1-dimethylethylene, n-pentylene, 2,2-dimethylpropylene, 2-methylbutylene, or a combination of two or more of these. In particular, it is preferably at least one selected from the group consisting of ethylene, isopropylene, and n-butylene. In the above formula (I), a plurality of R 1 may be the same or different, but are preferably the same. When R 1 has 6 or more carbon atoms such as n-hexene, the crystallinity of the polyether polycarbonate diol becomes high, and the flexibility, elongation, and bending properties of the obtained polishing pad at low temperature deteriorate, which may not be preferable. From such a viewpoint, R 1 is preferably a divalent hydrocarbon group having 2 to 5 carbon atoms.

[0044] In the above formula (I), n is from 2 to 30, preferably from 3 to 20, and more preferably from 3 to 15. In the above formula (I), m is from 0.1 to 20, preferably from 0.5 to 10, and more preferably from 1 to 5.

[0045] When the polyol having a carbonate group in the molecule contains a structural unit derived from polytetramethylene ether glycol and includes the polyether polycarbonate diol represented by the above formula (I), the structural unit derived from the polytetramethylene ether glycol is preferably a part represented by -(R 1 -O) n [[ID=3②]]- in the above formula (I).

[0046] The number-average molecular weight (Mna as described above) of polyols having carbonate groups in the molecule is preferably 200 to 5000, more preferably 500 to 3000, and most preferably 800 to 2500.

[0047] The number-average molecular weight of the structural units derived from the polytetramethylene ether glycol and the number-average molecular weight of the polyol having a carbonate group in the molecule can be calculated by performing the measurement in the same manner as described in the (Measurement Method) and (Measurement Conditions) of (Gel Permeation Chromatography (GPC) Measurement of Isocyanate-Terminated Urethane Prepolymer) in the [Examples] section below.

[0048] The content of the polyol having a carbonate group in its molecule relative to the entire isocyanate-terminated urethane prepolymer is preferably 15 to 75% by weight, more preferably 20 to 65% by weight, and most preferably 20 to 60% by weight. By having the content of the polyol having a carbonate group in its molecule within the above numerical range, an abrasive pad can be obtained that has excellent step-eliminating performance, can suppress dishing, and can suppress defects.

[0049] Other polyol components in the isocyanate-terminated urethane prepolymer that do not contain a carbonate group in the molecule include low molecular weight polyols, high molecular weight polyols other than those containing a carbonate group in the molecule, or combinations thereof. In some embodiments, a low molecular weight polyol is a polyol with a number average molecular weight of 30 to 300, and a high molecular weight polyol is a polyol with a number average molecular weight greater than 300. The number average molecular weight of the low molecular weight polyol and the high molecular weight polyol other than those containing a carbonate group in the molecule can be calculated by measuring them in the same manner as described in the (Measurement Method) and (Measurement Conditions) of (Gel Permeation Chromatography (GPC) Measurement of Isocyanate-Terminated Urethane Prepolymer) in the [Examples] section below.

[0050] Examples of the low molecular weight polyols mentioned above include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, or combinations of two or more of these, with diethylene glycol being preferred among them.

[0051] The content of low molecular weight polyols relative to the entire isocyanate-terminated urethane prepolymer can be 0-20% by weight, 2-15% by weight, or 3-10% by weight. Alternatively, the content of low molecular weight polyols can be 0% by weight (no low molecular weight polyols). In this application, "no low molecular weight polyols" means that a certain component is not intentionally added, and does not exclude the presence of impurities.

[0052] Other high molecular weight polyols besides the polyols having carbonate groups in the molecule include polyether polyols such as polytetramethylene ether glycol (PTMG), polyethylene glycol, and polypropylene glycol; Polyester polyols such as reaction products of ethylene glycol and adipic acid, or reaction products of butylene glycol and adipic acid; Polycarbonate polyol; Polycaprolactone polyol; Or a combination of two or more of these; In some embodiments, it is preferable that the high molecular weight polyol further comprises a polyether polyol.

[0053] The content of high molecular weight polyols (including polyols having a carbonate group in the molecule) relative to the entire isocyanate-terminated urethane prepolymer is preferably 25 to 75% by weight, more preferably 35 to 65% by weight, and most preferably 40 to 60% by weight.

[0054] The content of high molecular weight polyols other than polyols having carbonate groups in their molecules, relative to the entire isocyanate-terminated urethane prepolymer, is preferably 15 to 75% by weight, more preferably 20 to 65% by weight, and most preferably 25 to 60% by weight. Furthermore, the above-mentioned high molecular weight polyol may be composed of a polyol having a carbonate group in its molecule, or a polyol having a carbonate group in its molecule and a polyether polyol.

[0055] (Polyisocyanate component) The polyisocyanate components contained in isocyanate-terminated urethane prepolymers include: m-phenylenediisocyanate, p-phenylenediisocyanate, 2,6-Tolylene diisocyanate (2,6-TDI), 2,4-Tolylene 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'-dimethyldiphenylmethane-4,4'-diisocyanate, Xylylene-1,4-diisocyanate, 4,4'-Diphenylpropanediisocyanate, trimethylene diisocyanate, Hexamethylene diisocyanate, Propylene-1,2-diisocyanate, Butylene-1,2-diisocyanate, Cyclohexylene-1,2-diisocyanate, Cyclohexylene-1,4-diisocyanate, p-phenylenediisothiocyanate, Xylylene-1,4-diisothiocyanate, Ethyridine diisothiocyanate, Alternatively, a combination of two or more of these may be given. Among these, it is preferable to use tolylene isocyanates such as 2,6-tolylene diisocyanate (2,6-TDI) and 2,4-tolylene diisocyanate (2,4-TDI) from the viewpoint of the polishing characteristics and mechanical strength of the resulting polishing pad.

[0056] The content of the polyisocyanate component relative to the entire isocyanate-terminated urethane prepolymer is preferably 20 to 50% by weight, more preferably 25 to 35% by weight, and most preferably 30 to 40% by weight.

[0057] (Hardening agent) Examples of curing agents included in curable resin compositions include the amine-based curing agents described below. Examples of polyamines that constitute amine-based curing agents include diamines, which are alkylenediamines such as ethylenediamine, propylenediamine, and hexamethylenediamine; aliphatic ring-containing diamines such as isophoronediamine and dicyclohexylmethane-4,4'-diamine; aromatic ring-containing diamines such as 3,3'-dichloro-4,4'-diaminodiphenylmethane (also known as methylenebis-o-chloroaniline) (hereinafter abbreviated as MOCA); hydroxyl group-containing diamines such as 2-hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, and di-2-hydroxypropylethylenediamine, especially hydroxyalkylalkylenediamines; or combinations of two or more of these. In addition, trifunctional triamine compounds and polyamine compounds with four or more functions can also be used.

[0058] A particularly preferred curing agent is MOCA, as mentioned above, and the curing agent can also consist of MOCA. The chemical structure of MOCA is as follows.

[0059] [ka]

[0060] The total amount of curing agent used is such that the ratio of moles of NH2 in the curing agent to moles of NCO in the isocyanate-terminated urethane prepolymer (moles of NH2 / moles of NCO) is preferably 0.7 to 1.1, more preferably 0.75 to 1.0, and most preferably 0.8 to 0.95.

[0061] (Microscopic hollow spheres) In some embodiments, the curable resin composition may further contain microscopic hollow spheres. A foam can be formed by mixing micro-hollow spheres with a polyurethane resin. Micro-hollow spheres refer to unfoamed, heat-expandable micro-spherical bodies consisting of an outer shell (polymer shell) made of thermoplastic resin and low-boiling point hydrocarbons enclosed within the outer shell, and unfoamed, heat-expandable micro-spherical bodies that have been heated and expanded. As the polymer shell, for example, thermoplastic resins such as acrylonitrile-vinylidene chloride copolymer, acrylonitrile-methyl methacrylate copolymer, and vinyl chloride-ethylene copolymer can be used. Similarly, as the low-boiling point hydrocarbons enclosed within the polymer shell, for example, isobutane, pentane, isopentane, petroleum ether, or a combination of two or more of these can be used.

[0062] (Other ingredients) Other catalysts commonly used in this industry may be added to the curable resin composition. Furthermore, the polyisocyanate component described above can also be added to the curable resin composition later. The weight ratio of the additional polyisocyanate component to the total weight of the isocyanate-terminated urethane prepolymer and the additional polyisocyanate component is preferably 0.1 to 10% by weight, more preferably 0.5 to 8% by weight, and particularly preferably 1 to 5% by weight. As the polyisocyanate component to be added to the polyurethane resin curable composition, any of the above-mentioned polyisocyanate components can be used without particular limitation, but 4,4'-methylene-bis(cyclohexyl isocyanate) (hydrogenated MDI) is preferred.

[0063] 2. A method for polishing the surface of an optical material or semiconductor material. In this application, a method for polishing the surface of an optical material or semiconductor material includes the step of polishing the surface of the optical material or semiconductor material using the polishing pad described above. In some embodiments, a method for polishing the surface of an optical or semiconductor material may further include the step of supplying a slurry to the surface of a polishing pad, the surface of the optical or semiconductor material, or both.

[0064] (slurry) The liquid components in the slurry are not particularly limited, but include water (pure water), acids, alkalis, organic solvents, or combinations thereof, and are selected depending on the material of the object to be polished and the desired polishing conditions. Preferably, the slurry has water (pure water) as its main component, and preferably contains 80% by weight or more of water relative to the total slurry. The abrasive components in the slurry are not particularly limited, but include silica, zirconium silicate, cerium oxide, aluminum oxide, manganese oxide, or combinations thereof. The slurry may also contain other components such as organic substances soluble in the liquid components or pH adjusters. [Examples]

[0065] The present invention will be experimentally explained by the following examples, but the following explanation is not intended to be interpreted as limiting the scope of the present invention to these examples.

[0066] (material) The materials used in Examples 1-3 and Comparative Examples 1 and 2, described below, are listed below.

[0067] • Polyols containing carbonate groups within the molecule (used as raw materials for isocyanate-terminated urethane prepolymers) PEPCD(1)... A polyether polycarbonate diol containing structural units derived from polytetramethylene ether glycol with a number average molecular weight of 250, and having a number average molecular weight of 1000 (in formula (I) above, multiple R 1 Both are n-butylene, corresponding to a polyether polycarbonate diol with n = 3.2 and m = 2.8. PEPCD(2)... A polyether polycarbonate diol containing structural units derived from polytetramethylene ether glycol with a number average molecular weight of 650, and having a number average molecular weight of 2000 (in formula (I) above, multiple R 1 Both are n-butylene, corresponding to a polyether polycarbonate diol with n = 8.8 and m = 2.0.

[0068] • Isocyanate-terminated urethane prepolymer Prepolymer (1)...A urethane prepolymer with an NCO equivalent of 420, containing 414 parts by weight of 2,4-tolylene diisocyanate as a polyisocyanate component, 350 parts by weight of the above-mentioned PEPCD(1) and 175 parts by weight of polytetramethylene ether glycol with a number average molecular weight of 650 as high molecular weight polyol components, and 61 parts by weight of diethylene glycol as a low molecular weight polyol component. Prepolymer (2)...A urethane prepolymer with an NCO equivalent of 460, containing 400 parts by weight of 2,4-tolylene diisocyanate as a polyisocyanate component, 360 parts by weight of the above-mentioned PEPCD(1) and 179 parts by weight of polytetramethylene ether glycol with a number average molecular weight of 650 as high molecular weight polyol components, and 61 parts by weight of diethylene glycol as a low molecular weight polyol component. Prepolymer (3)...A urethane prepolymer with an NCO equivalent of 420, containing 393 parts by weight of 2,4-tolylene diisocyanate as a polyisocyanate component, 362 parts by weight of the above-mentioned PEPCD(2) and 181 parts by weight of polytetramethylene ether glycol with a number average molecular weight of 650 as high molecular weight polyol components, and 64 parts by weight of diethylene glycol as a low molecular weight polyol component.

[0069] Adiprene L325... A urethane prepolymer manufactured by Uniroyal Chemicals. (A urethane prepolymer with an NCO equivalent of 460, containing 2,4-tolylene diisocyanate and 4,4'-methylenebis(cyclohexyl isocyanate) (hydrogenated MDI) as polyisocyanate components, polytetramethylene ether glycol as a high molecular weight polyol component, and diethylene glycol as a low molecular weight polyol component.)

[0070] DC6912... A product name for a urethane prepolymer manufactured by Tosoh Corporation (a urethane prepolymer with an NCO equivalent of 540, containing 2,4-tolylene diisocyanate as a polyisocyanate component, polytetramethylene ether glycol as a high molecular weight polyol component, and diethylene glycol as a low molecular weight polyol component).

[0071] • Hardener: MOCA···3,3'-Dichloro-4,4'-diaminodiphenylmethane (also known as methylenebis-o-chloroaniline) (MOCA) (NH2 equivalent = 133.5)

[0072] • Microscopic hollow spheres: Expancel461DU20 (manufactured by Nippon Filight Co., Ltd.)

[0073] (Example 1) 1000g of prepolymer (1) was prepared as component A, 286g of MOCA (a curing agent) as component B, and 30g of micro hollow spheres (Expancel 461DU20) as component C. The proportions of each component are indicated in grams, but the required weight (parts) should be prepared according to the size of the block. The following calculations will also be in grams (parts). Component A and component C were mixed, and the resulting mixture of A and C was degassed under reduced pressure. Component B was also degassed under reduced pressure. The degassed mixture of A and C and the degassed component B were fed into a mixer to obtain a mixture of A, B, and C. The ratio of the number of moles of NH2 in MOCA of component B to the number of moles of NCO in the prepolymer of component A (moles of NH2 / moles of NCO) in the obtained mixture of A, B, and C is 0.9. The mixture of components A, B, and C was poured into a mold (850mm x 850mm square) heated to 80°C and primary cured at 80°C for 30 minutes. The formed resin foam was removed from the mold and secondary cured in an oven at 120°C for 4 hours. After the resulting resin foam was allowed to cool to 25°C, it was heated again in an oven at 120°C for 5 hours. The resulting resin foam was sliced ​​to a thickness of 1.3mm in the thickness direction to create a urethane sheet, and double-sided tape was attached to the back of this urethane sheet to create a polishing pad.

[0074] (Example 2) A urethane sheet was prepared and an abrasive pad was obtained in the same manner as in Example 1, except that 1000g of prepolymer (2) was used as component A instead of 1000g of prepolymer (1) of component A in Example 1, and the MOCA content of component B was changed from 286g to 261g. Furthermore, in the mixture of components A, B, and C, the ratio of moles of NH2 in MOCA (component B) to moles of NCO (component A) is 0.9.

[0075] (Example 3) A urethane sheet was prepared and an abrasive pad was obtained in the same manner as in Example 1, except that 1000g of prepolymer (3) was used as component A instead of 1000g of prepolymer (1) of component A in Example 1. Furthermore, in the mixture of components A, B, and C, the ratio of moles of NH2 in MOCA (component B) to moles of NCO (component A) is 0.9.

[0076] (Comparative Example 1) A urethane sheet was prepared and an abrasive pad was obtained in the same manner as in Example 1, except that 1000g of adiprene L325 was used as component A instead of 1000g of prepolymer (1) component A in Example 1, and the MOCA content of component B was changed from 286g to 261g. Furthermore, in the mixture of components A, B, and C, the ratio of moles of NH2 in MOCA (component B) to moles of NCO (component A) is 0.9.

[0077] (Comparative Example 2) A urethane sheet was prepared and an abrasive pad was obtained in the same manner as in Example 1, except that 1000g of DC6912 was used as component A instead of 1000g of prepolymer (1) component A in Example 1, and the MOCA content of component B was changed from 286g to 223g. Furthermore, in the mixture of components A, B, and C, the ratio of moles of NH2 in MOCA (component B) to moles of NCO (component A) is 0.9.

[0078] (Gel permeation chromatography (GPC) measurement of isocyanate-terminated urethane prepolymers) (Method for preparing the sample) 5 g each of the isocyanate-terminated urethane prepolymers used in Examples 1 and 2 and Comparative Examples 1 and 2 (prepolymers (1) and (2), adiprene L325, or DC6912) was placed in a container. 5 ml of N,N-dimethylformamide (DMF) solution containing methanol (methanol concentration: 33% by weight) was added to the container to obtain a mixture of prepolymer, methanol, and DMF. The mixture in the container was heated at 60°C for 1 hour while stirring to react the methanol with the isocyanate groups of the prepolymer, thereby sufficiently blocking (inactivating) the isocyanate groups. The container containing the mixture after inactivation of the isocyanate groups was left to stand overnight at room temperature (approximately 25°C) and allowed to cool. After cooling, 5 ml of DMF solution with a lithium bromide concentration of 10 mM (mmol / L) was added to the mixture in the container and stirred. 0.4 mL of the mixed solution after stirring was taken from the container and transferred to another container. A 5 mM lithium bromide DMF solution was added to this container to prepare a solution with a final concentration of approximately 1% by weight. The resulting solution was filtered through a 45 μm mesh filter, and the solid matter obtained on the filter after filtration was used as each sample. (Measurement method) For each sample obtained as described above, the molecular weight distribution in terms of polyethylene glycol / polyethylene oxide (PEG / PEO) was measured by GPC under the following measurement conditions. The peak in the molecular weight range of 200-400 was designated as Peak 1, the peak in the molecular weight range of 400-700 as Peak 2, and the peak in the molecular weight range of 700-10000 as Peak 3. The number-average molecular weight and weight-average molecular weight of the entire molecular weight distribution, as well as the number-average molecular weight, weight-average molecular weight, peak top, and abundance ratio of each of Peaks 1-3 were measured. The measurement results are shown in Table 1 and Figure 3. (Measurement conditions) Columns: Ohpak SB-802.5HQ (exclusion limit 10000) + SB-803HQ (exclusion limit 100000) Mobile phase: 5mM LiBr / DMF Flow rate: 0.3ml / min (26kg / cm 2 ) Oven: 60℃ Detector: RI 40℃ Sample volume: 20 μl

[0079] [Table 1]

[0080] In Table 1 and Figure 3, the peak in the molecular weight range of 200 to 400 (Peak 1) is thought to originate from unreacted (free) 2,4-tolylene diisocyanate, the peak in the molecular weight range of 400 to 700 (Peak 2) is thought to originate from a component formed by the addition of two molecules of 2,4-tolylene diisocyanate to both ends of one molecule of low molecular weight polyol (diethylene glycol) in the prepolymer, and the peak in the molecular weight range of 700 to 10000 (Peak 3) is thought to originate from a component formed by the addition of two molecules of 2,4-tolylene diisocyanate to both ends of one molecule of high molecular weight polyol (polyether polycarbonate diol or polytetramethylene ether glycol) in the prepolymer, and from an ultra-high molecular weight component formed by the addition of three or more molecules of 2,4-tolylene diisocyanate to two or more molecules of high molecular weight polyol (polyether polycarbonate diol or polytetramethylene ether glycol) in the prepolymer. From the results in Table 1, it was found that for the isocyanate-terminated urethane prepolymers used in Examples 1 and 2 (prepolymers (1) and (2)), the number average molecular weight of the entire molecular weight distribution of the prepolymers was less than or equal to Mna, and the peak top molecular weight of peak 3 was less than or equal to Mna + 1000 (where Mna is the number average molecular weight of polyether polycarbonate diol). Furthermore, when the same GPC measurement was performed on the isocyanate-terminated urethane prepolymer (prepolymer (3)) used in Example 3, it was found that, similar to Examples 1 and 2, the number-average molecular weight of the entire molecular weight distribution of the prepolymer was less than or equal to Mna, and the peak-top molecular weight of peak 3 was less than or equal to Mna + 1000 (where Mna is the number-average molecular weight of the polyether polycarbonate diol).

[0081] (Evaluation method) For each of the polishing pads in Examples 1 and 2, and Comparative Examples 1 and 2, the following evaluations were performed: (1) step-elimination performance and (2) defects.

[0082] (1) Performance in eliminating steps Each polishing pad was installed in a designated position on the polishing device using double-sided tape with acrylic adhesive, and polishing was performed under the conditions shown in <Polishing Conditions> below. After polishing, the step-leveling performance was evaluated by measuring with a micro-shape measuring device (KLA Tencor, P-16+OF). The evaluation results for each polishing pad are shown in Table 2 and Figures 4 and 5. <Measurement Procedure and Conditions> In this embodiment and comparative example, pattern wafers (insulating film: Si(OC2H5)4 film) with a Cu film thickness of approximately 7000 Å and step heights of 3000 to 3300 Å, and with different wiring widths, were polished using each polishing pad, adjusting the polishing rate so that the amount of polishing per pass was approximately 1000 Å. Polishing was performed in stages, and the step height of the wafer was measured each time. Step height measurements were performed for each wiring width portion on the pattern wafer. The graph in Figure 4(a) shows the results when polishing a Cu wiring with a width of 120 μm and an insulating film width of 120 μm, Figure 4(b) shows the results when polishing a Cu wiring with a width of 100 μm and an insulating film width of 100 μm, Figure 5(c) shows the results when polishing a Cu wiring with a width of 50 μm and an insulating film width of 50 μm, and Figure 5(d) shows the results when polishing a Cu wiring with a width of 10 μm and an insulating film width of 10 μm. The smaller the wiring width value, the finer the wiring becomes.

[0083] <Polishing conditions> Polishing machine used: F-REX300X (manufactured by Ebara Corporation) Disk: A188 (manufactured by 3M) Abrasive temperature: 20℃ Polishing plate rotation speed: 90 rpm Polishing head rotation speed: 81 rpm Polishing pressure: 3.5 psi Polishing slurry: CSL-9044C (Use a mixture of CSL-9044C concentrate and pure water in a weight ratio of 1:9) (Manufactured by Fujifilm Planar Solutions) Polishing slurry flow rate: 200 ml / min Polishing time: 60 seconds Workpiece to be polished: (Step reduction performance) Each of the pattern wafers mentioned above, (Defect) Cu film substrate Pad Break: 32N 10 minutes Conditioning: in-situ 18N 16 scans, ex-situ 35N 4 scans

[0084] (2) Defect Each polishing pad was placed in a predetermined position on the polishing apparatus using double-sided tape with an acrylic adhesive, and the Cu film substrate (a 12-inch diameter disc) was polished under the conditions described in (1) Polishing Conditions for Step Elimination Performance above. Cu film substrates that had undergone polishing treatment for the 16th, 26th, and 51st time were measured using a surface inspection device (KLA-Tencor, Surfscan SP2XP) in high-sensitivity measurement mode. The number of micro-scratches (fine dent-like scratches between 0.2 μm and 10 μm) on the entire substrate surface was observed and the total was calculated. The evaluation results are shown in Table 3 and Figure 6. A defect rate of 5 or fewer micro-scratches indicates a good performance.

[0085] [Table 2]

[0086] [Table 3]

[0087] The polishing pads of Examples 1 and 2 use a polyol with a number-average molecular weight of Mna that contains a carbonate group in its molecule, and relate to an isocyanate-terminated urethane prepolymer with a number-average molecular weight of Mna or less. On the other hand, the polishing pads of Comparative Examples 1 and 2 relate to an isocyanate-terminated urethane prepolymer that does not use a polyol that contains a carbonate group in its molecule. The polishing pads of Examples 1 and 2 are thought to exhibit the properties of the carbonate group more prominently because the number-average molecular weight of the isocyanate-terminated urethane prepolymer used is Mna or less and has excellent uniformity.

[0088] From the results in Tables 2 and 3 and Figures 4-6, it was found that the polishing pads of Examples 1 and 2 had superior step-elimination performance at all wiring widths compared to the polishing pads of Comparative Examples 1 and 2, and that scratches were significantly reduced, thus suppressing the occurrence of defects. This trend is expected to be similar in Example 3. From the above, it was found that polishing pads made from isocyanate-terminated urethane prepolymers with a number-average molecular weight of Mna or less, using a polyol with a number-average molecular weight of Mna and a carbonate group in the molecule, exhibit excellent uniformity and more pronounced properties of the carbonate group. As a result, dishing during polishing can be suppressed (excellent step-leveling performance) and the occurrence of defects can be suppressed.

Claims

1. A polishing pad having a polyurethane resin polishing layer, The polished layer is a cured product of a curable resin composition containing an isocyanate-terminated urethane prepolymer and a curing agent, wherein the number of moles of NCO in the isocyanate-terminated urethane prepolymer is the number of moles of NH in the curing agent. ２ The ratio of moles (NH ２ The ratio of moles of (NCO) is 0.7 to 1.1, and the isocyanate-terminated urethane prepolymer is a reaction product of a polyol component and a polyisocyanate component. The polyol component includes a high molecular weight polyol, and the content of the high molecular weight polyol relative to the entire isocyanate-terminated urethane prepolymer is 25 to 75% by weight. The high molecular weight polyol includes a polyol having a carbonate group in its molecule and a number-average molecular weight of Mna, and the content of the polyol having a carbonate group in its molecule relative to the entire isocyanate-terminated urethane prepolymer is 15 to 75% by weight. The polishing pad wherein the number-average molecular weight of the isocyanate-terminated urethane prepolymer is less than or equal to Mna.

2. The polishing pad according to claim 1, wherein, in the molecular weight distribution of the isocyanate-terminated urethane prepolymer measured by gel permeation chromatography (GPC) in terms of polyethylene glycol / polyethylene oxide (PEG / PEO), the molecular weight of the peak top of the peak located in the molecular weight region of 700 to 10000 is Mna + 1000 or less.

3. The polishing pad according to claim 1 or 2, wherein the number average molecular weight Mna of the polyol having a carbonate group in the molecule is 500 to 2500.

4. The polishing pad according to any one of claims 1 to 3, wherein the number average molecular weight of the isocyanate-terminated urethane prepolymer is 3500 or less.

5. The polishing pad according to claim 4, wherein the number average molecular weight of the isocyanate-terminated urethane prepolymer is 2000 or less.

6. The polishing pad according to any one of claims 1 to 5, wherein the polyol having a carbonate group in the molecule comprises structural units derived from polytetramethylene ether glycol.

7. The polishing pad according to any one of claims 1 to 6, wherein the polyol having a carbonate group in the molecule comprises a polyether polycarbonate diol represented by the following formula (I): 【Chemistry 1】 (In the above formula (I), R １ is a divalent hydrocarbon group having 2 to 10 carbon atoms, and multiple R １ They may be the same or they may be different. n is between 2 and 30. m is between 0.1 and 20.

8. R in formula (I) １ The polishing pad according to claim 7, wherein the material is at least one selected from the group consisting of ethylene, isopropylene, and n-butylene.

9. The polishing pad according to any one of claims 1 to 8, wherein the high molecular weight polyol further comprises a polyether polyol.

10. The polishing pad according to any one of claims 1 to 9, wherein the polyisocyanate component comprises tolylene diisocyanate.

11. The polishing pad according to any one of claims 1 to 10, wherein the curing agent comprises 3,3'-dichloro-4,4'-diaminodiphenylmethane.

12. The polishing pad according to any one of claims 1 to 11, wherein the curable resin composition further comprises micro hollow spheres.

13. A method for manufacturing an abrasive pad according to any one of claims 1 to 12, comprising the step of forming the abrasive layer.

14. A method for polishing the surface of an optical material or a semiconductor material, comprising the step of polishing the surface of the optical material or a semiconductor material using a polishing pad according to any one of claims 1 to 12.

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