JP2023049625A - Polishing pad, method for manufacturing polishing pad, and method for polishing surface of optical material or semiconductor material - Google Patents

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

The present invention relates to a polishing pad, a method for manufacturing a polishing pad, and a method for polishing the surface of optical or semiconductor materials. The polishing pad of the present invention is used for polishing optical materials, semiconductor wafers, semiconductor devices, substrates for hard disks, etc., and is particularly suitable for polishing devices in which an oxide layer, a metal layer, etc. are formed on a semiconductor wafer. used for

Optical materials, semiconductor wafers, hard disk substrates, liquid crystal glass substrates, and semiconductor devices require extremely precise flatness. A hard polishing pad is commonly used to polish the surfaces of such various materials, particularly the surfaces of semiconductor devices, to a flat surface.
Currently, the polishing layer in many hard polishing pads contains isocyanate-terminated polyols, which are the reaction products of isocyanate components such as tolylene diisocyanate (TDI) and polyol components, including high molecular weight polyols such as polytetramethylene ether glycol (PTMG). It is common to use a rigid polyurethane material obtained by curing a urethane prepolymer with a curing agent such as 3,3'-dichloro-4,4'-diaminodiphenylmethane. High-molecular-weight polyols that form isocyanate-terminated urethane prepolymers form the soft segments of polyurethane, and PTMG has been commonly used as the high-molecular-weight polyol from the viewpoint of ease of handling and appropriate rubber elasticity.

In the polishing of semiconductor devices, along with the miniaturization and high density of integrated circuits in recent years, there is a stricter level for improving the ability to eliminate unevenness on the surface of the object to be polished and suppressing defects such as scratches. is now required. Insufficient level difference elimination performance on the surface of the object to be polished causes a phenomenon called dishing, in which the cross section of the wiring is depressed in a dish-like shape, mainly in wide wiring patterns, and the local flatness of the surface to be polished deteriorates. .

Conventional polishing pads using PTMG as a high-molecular-weight polyol are sometimes insufficient in terms of step elimination performance and defect suppression, and the use of polyols other than PTMG as a high-molecular-weight polyol is being studied.

Patent Document 1 discloses that a polishing pad formed using polypropylene glycol (PPG) as a high-molecular-weight polyol of an isocyanate-terminated urethane prepolymer has excellent step elimination performance and less defects.

JP 2020-157415 A

However, when 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 is poor, and the life of the polishing pad may be shortened. In addition, as in the polishing pad described in Patent Document 1, when the total amount of high-molecular-weight polyol is PPG, the resulting isocyanate-terminated urethane prepolymer tends to soften. In producing the polymer, it is necessary to newly adjust the equivalents of the polyol component and the polyisocyanate component.

As described above, there is a demand for a polishing pad that is excellent in level difference elimination performance, can suppress dishing, and can suppress defects.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a polishing pad that has excellent step elimination performance, suppresses dishing, and suppresses defects.

As a result of intensive research to solve the above problems, the present inventors have found that a polyol having a carbonate group in the molecule is used as a high-molecular-weight polyol component for forming an isocyanate-terminated urethane prepolymer, and the weight of the isocyanate-terminated urethane prepolymer is By setting the average molecular weight to 2,000 or less, the inventors have found that the above problems can be solved, and have completed the present invention. Specific aspects of the present invention are as follows.

（上記式（Ｉ）中、
Ｒ^１は炭素数２～１０の二価の炭化水素基であり、複数のＲ^１は同一であってもよく、又は異なるものであってもよく、
ｎは２～３０であり、
ｍは０．１～２０である。）。
[８] 前記式（Ｉ）におけるＲ^１が、エチレン、イソプロピレン、及びｎ－ブチレンからなる群から選択される少なくとも１種である、[７]に記載の研磨パッド。
[９] 前記高分子量ポリオールがポリエーテルポリオールをさらに含む、[１]～[８]のいずれか１つに記載の研磨パッド。
[１０] 前記ポリイソシアネート成分がトリレンジイソシアネートを含む、[１]～[９]のいずれか１つに記載の研磨パッド。
[１１] 前記硬化剤が３，３’－ジクロロ－４，４’－ジアミノジフェニルメタンを含む、[１]～[１０]のいずれか１つに記載の研磨パッド。
[１２] 前記硬化性樹脂組成物が微小中空球体をさらに含む、[１]～[１１]のいずれか１つに記載の研磨パッド。
[１３] [１]～[１２]のいずれか１つに記載の研磨パッドの製造方法であって、前記研磨層を成形する工程を含む、前記方法。
[１４] 光学材料又は半導体材料の表面を研磨する方法であって、[１]～[１２]のいずれか１つに記載の研磨パッドを使用して光学材料又は半導体材料の表面を研磨する工程を含む、前記方法。 [1] A polishing pad having a polishing layer containing a polyurethane resin,
The polyurethane resin is a cured product of a curable resin composition containing 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 comprises a high molecular weight polyol,
The high molecular weight polyol contains a polyol having a carbonate group in the molecule and a number average molecular weight of Mna,
The polishing pad, wherein the isocyanate-terminated urethane prepolymer has a number average molecular weight of Mna or less.
[2] The peak top of the peak present in the molecular weight region of 700 to 10,000 in the molecular weight distribution in terms of polyethylene glycol/polyethylene oxide (PEG/PEO) measured by gel permeation chromatography (GPC) of the isocyanate-terminated urethane prepolymer. has a molecular weight of Mna+1000 or less, the polishing pad according to [1].
[3] The polishing pad according to [1] or [2], wherein the polyol having carbonate groups in the molecule has a number average molecular weight Mna of 500 to 2,500.
[4] The polishing pad according to any one of [1] to [3], wherein the isocyanate-terminated urethane prepolymer has a number average molecular weight of 3,500 or less.
[5] The polishing pad of [4], wherein the isocyanate-terminated urethane prepolymer has a number average molecular weight of 2,000 or less.
[6] The polishing pad according to any one of [1] to [5], wherein the polyol having a carbonate group in its molecule contains a structural unit derived from polytetramethylene ether glycol.
[7] The polishing pad according to any one of [1] to [6], wherein the polyol having a carbonate group in the molecule comprises a polyether polycarbonate diol represented by the following formula (I):

(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 0.1-20. ).
[8] The polishing pad of [7], wherein R ¹ in 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 hollow microspheres.
[13] A method for manufacturing a polishing pad according to any one of [1] to [12], comprising the step of molding the polishing layer.
[14] A method of polishing the surface of an optical material or a semiconductor material, the step of polishing the surface of the optical material or the semiconductor material using the polishing pad according to any one of [1] to [12]. The above method, comprising

(definition)
In the present application, when a numerical range is expressed using "X to Y", the range includes X and Y which are numerical values at both ends.

The polishing pad of the present invention is excellent in eliminating unevenness, can suppress dishing, and can suppress defects.

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

(Action)
The present inventors have conducted intensive research on the relationship between the type of polyol component forming the isocyanate-terminated urethane prepolymer and the molecular weight distribution of the isocyanate-terminated urethane prepolymer, the step elimination performance, and defects. By using a polyol having a carbonate group in the molecule and a number average molecular weight of Mna as the high molecular weight polyol component forming the urethane prepolymer, and setting the number average molecular weight of the isocyanate-terminated urethane prepolymer to Mna or less, The present inventors have found that a polishing pad can be obtained which is excellent in level difference eliminating performance, can suppress dishing, and can suppress defects. Although the details of the reason why such characteristics are obtained are not clear, it is speculated as follows.

A polyol having a carbonate group in its molecule is considered to have lower crystallinity than PTMG because it has a carbonate group. likely to be lower. It is thought that when the crystallinity of the isocyanate-terminated urethane prepolymer forming the polishing layer becomes low, it becomes difficult for dusts and the like of the polishing layer generated during polishing to aggregate and form large lumps. In addition, when the number average molecular weight of the prepolymer is Mna or less, the content of the ultrahigh molecular weight component described later is small, and the prepolymer is excellent in uniformity, so it is considered that the characteristics of the carbonate group can be exhibited more remarkably. As a result, it is presumed that, in the object to be polished, the ability to eliminate unevenness is improved, dishing can be suppressed, and defects can be suppressed.

(Bump elimination performance)
There is a damascene process as a method of manufacturing metal (Cu) wiring in a semiconductor manufacturing process. In this damascene process, grooves are formed in an insulating film provided on a silicon wafer, metal is embedded in the grooves by sputtering or the like, and excess metal is removed by chemical mechanical polishing (CMP) to form metal wiring. In order to eliminate the physical or chemical stress generated between the insulating film and the metal, the insulating film is usually covered with a barrier metal before the metal is embedded.

Schematic diagrams of experiments for evaluating step elimination performance are shown in (a) to (c) of FIG. FIG. 1(a) shows the state before the start of polishing. As shown in FIG. 1A, when a metal film (Cu film) 20 is embedded in a groove of an insulating film (oxide film) 10, a groove exists according to the width of the groove existing under the metal film 20. A step (difference in thickness between a portion without a groove and a portion with a groove) 40 corresponding to the width and depth of the groove is generated between the portion where the groove exists and the portion where the groove does not exist. In FIG. 1(a), the thickness 30 of the metal film 20 where no groove exists is 8000 Å, and the step 40 is 3500 Å. FIG. 1(b) shows a state where the polishing amount is 2000 Å, and the step 41 is 2000 Å. FIG. 1(c) shows a state where the polishing amount is 6000 Å, and the step 42 is almost zero.

In the present application, the term "level difference elimination performance" refers to the performance of reducing the level difference of a pattern wafer having the above-described level difference (unevenness) when polishing is performed.
In FIG. 2, a polishing pad A (dotted line) having high level difference elimination performance and a polishing pad B (solid line) having relatively low level difference elimination performance were used for the object to be polished in the state of (a) of FIG. 4 shows a graph showing the relationship between the polishing amount (Å) and the step (Å) in each case. 2 correspond to the states of (a) to (c) in FIG. 1, respectively. In FIG. 2, although there is no step difference between the dotted line and the solid line before the start of polishing (location (a)), polishing progresses and when the amount of polishing is 2000 Å, the polishing pad A (dotted line) becomes: It is indicated that the step is smaller than that of the polishing pad B (solid line) (location (b)). As can be seen from FIG. 2, the polishing pad A (dotted line) eliminates the unevenness faster than the polishing pad B (solid line) (part (c)). From the results of FIG. 2, it can be said that the polishing pad A indicated by the dotted line has a relatively higher step elimination performance than the polishing pad B indicated by the solid line.

(defect)
In the present application, the term "defect" includes "particles" indicating residual fine particles adhering to the surface of the object to be polished, "pad dust" indicating scraps of the polishing layer adhering to the surface of the object to be polished, and It is a general term for defects including "scratches" indicating flaws on the surface of the polished product, and "defect performance" refers to the ability to reduce these "defects".

The polishing pad of the present application, the method for manufacturing the polishing pad, and the method for polishing the surface of an optical material or a semiconductor material will be described below.

1. Polishing Pad, Method of Making Polishing Pad In some embodiments of the present application, the polishing pad has a polishing layer comprising a polyurethane resin, the polyurethane resin comprising 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 contains a high molecular weight polyol, the high molecular weight polyol contains a polyol having a carbonate group in the molecule and a number average molecular weight of Mna,
The isocyanate-terminated urethane prepolymer has a number average molecular weight of Mna or less.

(polishing pad)
The polishing pad of the present application has a polishing layer containing polyurethane resin. The polishing layer is placed 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, for example, a highly elastic material such as rubber. Depending on the rigidity of the polishing pad, the polishing layer can be a polishing pad.

Except for being able to suppress dishing and defects in the object to be polished, the polishing pad of the present application has no major difference in shape from a general polishing pad, and can be used in the same manner as a general polishing pad. The polishing layer can be pressed against the material to be polished while rotating the pad, or the material to be polished can be pressed against the polishing layer while rotating.

The polishing pad of the present application can be produced by generally known manufacturing methods such as molding and slab molding. First, a polyurethane block is formed by these manufacturing methods, the block is sliced into a sheet, a polishing layer formed from a polyurethane resin is formed, and the polishing layer is adhered to a support or the like. Alternatively, the abrasive layer can be molded directly onto the support.

More specifically, the polishing layer is formed by attaching a double-sided tape to the surface opposite to the polishing surface of the polishing layer and cutting it into a predetermined shape to form a polishing pad. The double-sided tape is not particularly limited, and can be used by arbitrarily selecting from double-sided tapes known in the art. Further, the polishing pad may have a single-layer structure consisting of only the polishing layer, or may consist of multiple layers in which other layers (lower layer, support layer) are laminated on the side opposite to the polishing surface of the polishing layer. may

The polishing layer is formed by preparing a curable resin composition containing an isocyanate-terminated urethane prepolymer and a curing agent and curing the curable resin composition.
The polishing layer can be composed of foamed polyurethane resin, and the foaming can be performed by dispersing a foaming agent containing micro hollow spheres in the polyurethane resin. In this case, molding can be performed by preparing a curable resin composition containing an isocyanate-terminated urethane prepolymer, a curing agent, and a foaming agent, and foaming and curing the curable resin composition.
The curable resin composition may be, for example, a two-pack composition prepared by mixing a liquid A containing an isocyanate-terminated urethane prepolymer and a liquid B containing a curing agent component. Other components may be added to either liquid A or liquid B, but if a problem occurs, the composition may be further divided into a plurality of liquids and mixed with three or more liquids. be able to.

(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, said polyol component comprising a high molecular weight polyol, said high molecular weight polyol being a contains a polyol having a carbonate group in its molecule.

The number average molecular weight of the isocyanate-terminated urethane prepolymer is Mna or less, where Mna is the number average molecular weight of the above polyol having a carbonate group in the molecule. below is preferable, and 900 or less is most preferable. The high-molecular-weight polyol contains a polyol with a number average molecular weight of Mna having a carbonate group in the molecule, and the isocyanate-terminated urethane prepolymer has a number average molecular weight of Mna or less. A polishing pad capable of suppressing defects is obtained.

The means for making the number average molecular weight of the isocyanate-terminated urethane prepolymer equal to or less than the above Mna is not particularly limited, but for example, two or more high-molecular-weight polyol molecules included in the peak present in the molecular weight region of 700 to 10,000 described later. Polyisocyanate component By reducing the content ratio of the ultra-high molecular weight component formed by addition of 3 or more molecules, and by increasing the content ratio of the component contained in the peak existing in the molecular weight region of 400 to 700, which will be described later. , can be achieved. Means for reducing the content ratio of the above-mentioned ultra-high molecular weight component with respect to the entire isocyanate-terminated urethane prepolymer are not particularly limited. For example, by setting the reaction conditions of (1) to mild conditions, it is possible to suppress chain-like generation of ultra-high-molecular-weight components. Means for increasing the content ratio of the component contained in the peak present in the molecular weight region of 400 to 700 with respect to the entire isocyanate-terminated urethane prepolymer is not particularly limited, but the reaction conditions are adjusted to obtain one molecule of low molecular weight polyol. A means for increasing the content of a component formed by adding two molecules of a polyisocyanate component to both ends can be mentioned.

The isocyanate-terminated urethane prepolymer may also have a number average molecular weight of 500-2500. The upper limit of the number average molecular weight of the isocyanate-terminated urethane prepolymer may be 3500 or less, 2500 or less, 2000 or less, 1500 or less, or 1000 or less, and the lower limit may be 500 or more, 600 or more, 700 or more, or It can be 800 or more. These upper and lower limits can be combined arbitrarily.

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

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

In some embodiments, the content of the component contained in the peak present in the molecular weight region of 400 to 700 is preferably 5 to 40%, more preferably 10 to 35%, relative to the entire isocyanate-terminated urethane prepolymer. is more preferred, and 15 to 30% is most preferred. Further, the peak present in the molecular weight region of 400 to 700 is preferably derived from a component formed by adding two molecules of the polyisocyanate component to both ends of one molecule of the low molecular weight polyol.

In some embodiments, the upper limit of the content ratio of the components contained in the peak present in the molecular weight region of 700 to 10000 with respect to the entire isocyanate-terminated urethane prepolymer is preferably 80% or less, and 78% or less. is more preferable, and 76% or less is most preferable. The lower limit of the content ratio 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 combined arbitrarily. In addition, the peak present in the molecular weight region of 700 to 10000 is a component formed by adding two polyisocyanate component molecules to both ends of one high molecular weight polyol molecule, and polyisocyanate component 3 to two or more high molecular weight polyol molecules. It is preferably derived from an ultra-high molecular weight component formed by addition of more than one molecule.

The peak present in the molecular weight region of 700 to 10,000 includes an ultra-high molecular weight component (high molecular weight polyol with a number average molecular weight Mna of 1,000) formed by addition of 2 or more molecules of high molecular weight polyol and 3 or more molecules of polyisocyanate component. In that case, the molecular weight of the ultra-high molecular weight component is 2000 or more). In the present application, it is preferable that the content of the ultrahigh molecular weight component is small. Since the peak existing in the molecular weight region of 700 to 10,000 is broad, it is relatively difficult to specify the content of the ultrahigh molecular weight component. However, the content of the ultra-high molecular weight component can be estimated from the number average molecular weight of the entire isocyanate-terminated prepolymer or the peak top molecular weight of the peak present in the molecular weight region of 700 to 10,000. It can be estimated that the smaller the number average molecular weight of the entire isocyanate-terminated prepolymer and/or the peak top molecular weight of the peak present in the molecular weight region of 700 to 10,000, the lower the content of the ultrahigh molecular weight component. In some embodiments, the peak top molecular weight of the peak present in the molecular weight region of 700 to 10000 is Mna + 1000 or less (Mna is the number average molecular weight of the polyol having a carbonate group in the molecule). When Mna is 1,000, the peak top molecular weight is preferably 2,000 or less, more preferably 1,850 or less, and most preferably 1,700 or less. When Mna is 2,000, the peak top molecular weight is preferably 3,000 or less, more preferably 2,850 or less, and most preferably 2,700 or less. In addition, the peak top molecular weight of the peak present in the molecular weight region of 700 to 10000 can have a lower limit of 1000 or more, 1300 or more, or 1500 or more, and the upper limit can be 3000 or less, 2850 or less, It can also be 2700 or less, 2000 or less, 1850 or less, or 1700 or less. These lower and upper limits can be combined arbitrarily. Since the prepolymer has excellent uniformity due to the low content of the ultrahigh molecular weight component, it is believed that the properties of the carbonate group can be exhibited more remarkably. As a result, it is presumed that, in the object to be polished, the ability to eliminate unevenness is improved, dishing can be suppressed, and defects can be suppressed.

The number average molecular weight and weight average molecular weight of the above-described isocyanate-terminated urethane prepolymer, the content of the components contained in each peak, and the number average molecular weight, weight average molecular weight, and peak top molecular weight of each peak are described in [Examples ] (Gel permeation chromatography (GPC) measurement of isocyanate-terminated urethane prepolymer) (Sample preparation method), (Measurement method), and (Measurement conditions) based on the procedures described in Prepare and measure the sample. can be calculated by performing

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

(polyol component)
The above-mentioned polyols having carbonate groups in the molecule are one kind of high molecular weight polyols.

A polyol having a carbonate group in the molecule preferably contains a structural unit derived from polytetramethylene ether glycol. The number average molecular weight of the structural unit derived from the polytetramethylene ether glycol is preferably 100-1500, more preferably 150-1000, and most preferably 200-850.

The polyol having a carbonate group in the molecule preferably contains a polyether polycarbonate diol represented by the following formula (I), and more preferably consists of a polyether polycarbonate diol represented by the following formula (I). .

（上記式（Ｉ）中、
Ｒ^１は炭素数２～１０の二価の炭化水素基であり、複数のＲ^１は同一であってもよく、又は異なるものであってもよく、
ｎは２～３０のであり、
ｍは１～２０のである。）。

(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 from 2 to 30;
m is from 1 to 20; ).

In the above formula (I) representing the above polyether polycarbonate diol, R ¹ is a divalent hydrocarbon group having 2 to 10 carbon atoms, and examples of R ¹ are ethylene, n-propylene, isopropylene, n -butylene, isobutylene, 1,1-dimethylethylene, n-pentylene, 2,2-dimethylpropylene, 2-methylbutylene, or combinations of two or more thereof, particularly ethylene, isopropylene, and n-butylene. In formula (I) above, a plurality of R ¹ may be the same or different, but are preferably the same. If R ¹ has 6 or more carbon atoms such as n-hexene, the crystallinity of the polyether polycarbonate diol increases, and the resulting polishing pad has poor flexibility, elongation, and flexibility at low temperatures. I don't like it. From this point of view, R ¹ is preferably a divalent hydrocarbon group having 2 to 5 carbon atoms.

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

When the polyol having a carbonate group in the molecule contains structural units derived from polytetramethylene ether glycol and contains the polyether polycarbonate diol represented by the above formula (I), it is derived from the polytetramethylene ether glycol. The structural unit is preferably the portion represented by —(R ¹ —O) _n — in formula (I) above.

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

The number-average molecular weight of the structural unit derived from the polytetramethylene ether glycol and the number-average molecular weight of the polyol having a carbonate group in the molecule are obtained by gel permeation chromatography of the isocyanate-terminated urethane prepolymer in [Example] below. It can be calculated by measuring in the same manner as described in (Measuring method) and (Measuring conditions) of Graphography (GPC) measurement).

The content of the polyol having a carbonate group in the molecule is preferably 15 to 75% by weight, more preferably 20 to 65% by weight, and most preferably 20 to 60% by weight, based on the entire isocyanate-terminated urethane prepolymer. When the content of the polyol having a carbonate group in the molecule is within the above numerical range, it is possible to obtain a polishing pad that is excellent in level difference elimination performance, can suppress dishing, and can suppress defects.

The polyol component other than the polyol having a carbonate group in the molecule contained in the isocyanate-terminated urethane prepolymer includes a low molecular weight polyol, a high molecular weight polyol other than the polyol having a carbonate group in the molecule, or a combination thereof. be done. In some embodiments, a low molecular weight polyol is a polyol with a number average molecular weight of 30-300 and a high molecular weight polyol is a polyol with a number average molecular weight of greater than 300. The number-average molecular weight of the low-molecular-weight polyol and the high-molecular-weight polyol other than the polyol having a carbonate group in the molecule is measured by gel permeation chromatography (GPC) measurement of isocyanate-terminated urethane prepolymer in [Example] described later. It can be calculated by measuring in the same manner as described in (Measurement method) and (Measurement conditions).

Examples of the low molecular weight polyol include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, and pentanediol. , 3-methyl-1,5-pentanediol, 1,6-hexanediol, or a combination of two or more thereof, among which diethylene glycol is preferred.

The low molecular weight polyol content can be 0 to 20 wt%, 2 to 15 wt%, or 3 to 10 wt% based on the total isocyanate-terminated urethane prepolymer. Alternatively, the content of the low-molecular-weight polyol can be 0% by weight (no low-molecular-weight polyol is included). In the present application, "does not contain" means that a certain component is not intentionally added, and does not exclude that it is contained as an impurity.

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 and reaction products of butylene glycol and adipic acid;
polycarbonate polyols;
polycaprolactone polyol;
or a combination of two or more of these;
In some embodiments it is preferred that the high molecular weight polyol further comprises a polyether polyol.

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

The content of the high-molecular-weight polyol other than the polyol having a carbonate group in the molecule is preferably 15 to 75% by weight, more preferably 20 to 65% by weight, more preferably 25 to 60% by weight, based on the entire isocyanate-terminated urethane prepolymer. Most preferred.
The high-molecular-weight polyol can also be composed of a polyol having a carbonate group in the molecule, or a polyol and a polyether polyol having a carbonate group in the molecule.

(Polyisocyanate component)
As the polyisocyanate component contained in the isocyanate-terminated urethane prepolymer,
m-phenylene diisocyanate,
p-phenylene diisocyanate,
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'-diphenylpropane diisocyanate,
trimethylene diisocyanate,
hexamethylene diisocyanate,
propylene-1,2-diisocyanate,
butylene-1,2-diisocyanate,
cyclohexylene-1,2-diisocyanate,
cyclohexylene-1,4-diisocyanate,
p-phenylene diisothiocyanate,
xylylene-1,4-diisothiocyanate,
ethylidine diisothiocyanate,
Alternatively, a combination of two or more of these may be mentioned.
Among these, 2,6-tolylene diisocyanate (2,6-TDI), 2,4-tolylene diisocyanate (2,4-TDI) and the like are considered from the viewpoint of the polishing properties and mechanical strength of the resulting polishing pad. Preference is given to using tolylene diisocyanate.

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

(curing agent)
Examples of the curing agent contained in the curable resin composition include amine-based curing agents described below.
Examples of polyamines constituting amine-based curing agents include diamines, including alkylenediamines such as ethylenediamine, propylenediamine and hexamethylenediamine; fatty acids such as isophoronediamine and dicyclohexylmethane-4,4′-diamine; diamines having an aromatic ring; diamines having an aromatic ring such as 3,3′-dichloro-4,4′-diaminodiphenylmethane (also known as methylenebis-o-chloroaniline) (hereinafter abbreviated as MOCA); Diamines having a hydroxyl group such as hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, especially hydroxyl alkylalkylene diamines; or combinations of two or more of these. Tri-functional triamine compounds and tetra- or higher-functional polyamine compounds can also be used.

A particularly preferred curing agent is MOCA as described above, and the curing agent can also consist of MOCA. The chemical structure of this MOCA is as follows.

The total amount of the curing agent is such that the ratio of the number of moles of _NH2 in the curing agent to the number of 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.

(micro hollow sphere)
In some embodiments, the curable resin composition can further include hollow microspheres.
A foam can be formed by mixing hollow microspheres into a polyurethane resin. The hollow microspheres are unfoamed heat-expandable microspheres composed of an outer shell (polymer shell) made of a thermoplastic resin and a low boiling point hydrocarbon contained in the outer shell, and unfoamed heat-expandable microspheres. It refers to a spherical body that has been expanded by heating. Thermoplastic resins such as acrylonitrile-vinylidene chloride copolymer, acrylonitrile-methyl methacrylate copolymer, and vinyl chloride-ethylene copolymer can be used as the polymer shell. Similarly, low-boiling hydrocarbons encapsulated in the polymer shell can be, for example, isobutane, pentane, isopentane, petroleum ether, or a combination of two or more thereof.

(other ingredients)
In addition, a catalyst generally used in the industry may be added to the curable resin composition.
Further, the above-described polyisocyanate component can be additionally added to the curable resin composition afterward, and the weight ratio of the additional polyisocyanate component to the total weight of the isocyanate-terminated urethane prepolymer and the additional polyisocyanate component is 0.1 to 10% by weight is preferred, 0.5 to 8% by weight is more preferred, and 1 to 5% by weight is particularly preferred.
As the polyisocyanate component to be additionally added to the curable polyurethane resin composition, the above-described polyisocyanate component can be used without particular limitation. is preferred.

2. Method of Polishing Surface of Optical or Semiconductor Material In the present application, a method of polishing a surface of an optical or semiconductor material includes polishing the surface of the optical or semiconductor material using the polishing pad described above.
In some embodiments, the method of polishing a surface of an optical or semiconductor material can further include applying a slurry to the surface of the polishing pad, the surface of the optical or semiconductor material, or both.

(slurry)
The liquid component contained in the slurry is not particularly limited, but includes water (pure water), acid, alkali, organic solvent, or a combination thereof, and is selected depending on the material of the object to be polished and desired polishing conditions. . The slurry preferably contains water (pure water) as a main component, and preferably contains 80% by weight or more of water with respect to the entire slurry. Abrasive components included in the slurry include, but are not limited to, silica, zirconium silicate, cerium oxide, aluminum oxide, manganese oxide, or combinations thereof. The slurry may contain other components such as an organic substance soluble in the liquid component and a pH adjuster.

The present invention will be experimentally illustrated by the following examples, but the following descriptions are not intended to be construed as limiting the scope of the present invention to the following examples.

(material)
Materials used in Examples 1 to 3 and Comparative Examples 1 and 2, which will be described later, are listed below.

・Polyol with a carbonate group in the molecule (used as raw material for isocyanate-terminated urethane prepolymer)
PEPCD (1): a polyether polycarbonate diol containing a structural unit derived from polytetramethylene ether glycol having a number average molecular weight of 250 and having a number average molecular weight of 1000 (in the above formula (I), a plurality of R ¹ Both are n-butylene and correspond to polyether polycarbonate diols in which n is 3.2 and m is 2.8.)
PEPCD (2): a polyether polycarbonate diol containing a structural unit derived from polytetramethylene ether glycol having a number average molecular weight of 650 and having a number average molecular weight of 2000 (in the above formula (I), a plurality of R ¹ Both are n-butylene and correspond to polyether polycarbonate diols with n=8.8 and m=2.0.)

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

Adiprene L325: Trade name of urethane prepolymer manufactured by Uniroyal Chemical Co. (including 2,4-tolylene diisocyanate and 4,4′-methylenebis(cyclohexyl isocyanate) (hydrogenated MDI) as polyisocyanate components, high molecular weight A urethane prepolymer having an NCO equivalent of 460 containing polytetramethylene ether glycol as a polyol component and diethylene glycol as a low-molecular-weight polyol component)

DC6912: trade name of urethane prepolymer manufactured by Tosoh Corporation (including 2,4-tolylene diisocyanate as a polyisocyanate component, polytetramethylene ether glycol as a high-molecular-weight polyol component, and Urethane prepolymer with NCO equivalent weight of 540 containing diethylene glycol)

・Curing agent:
MOCA 3,3′-dichloro-4,4′-diaminodiphenylmethane (also known as methylenebis-o-chloroaniline) (MOCA) (NH ₂ equivalent = 133.5)

・Micro hollow spheres:
Expancel461DU20 (manufactured by Nippon Philite Co., Ltd.)

(Example 1)
1000 g of prepolymer (1) was prepared as component A, 286 g of MOCA as a curing agent as component B, and 30 g of hollow microspheres (Expancel 461DU20) as component C, respectively. In order to show the ratio of each component, it is described in terms of grams, but the necessary weight (parts) may be prepared according to the size of the block. In the following description, g (parts) is used in the same manner.
The A component and the C component were mixed, and the resulting mixture of the A component and the C component was defoamed under reduced pressure. In addition, the B component was also degassed under reduced pressure. A mixture of defoamed A component and C component and defoamed B component were supplied to a mixer to obtain a mixed liquid of A component, B component and C component. In the resulting mixture of components 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 (number of moles of _NH2 / number of moles of NCO) is 0.9.
The obtained mixture of A component, B component, and C component was poured into a mold (850 mm×850 mm square shape) heated to 80° C. and primary cured at 80° C. for 30 minutes. The formed resin foam was extracted from the mold and was subjected to secondary curing in an oven at 120° C. for 4 hours. After allowing the resulting resin foam to cool to 25° C., it was heated again in an oven at 120° C. for 5 hours. A urethane sheet was prepared by slicing the obtained resin foam into a thickness of 1.3 mm in the thickness direction, and a double-faced tape was attached to the back surface of the urethane sheet to obtain a polishing pad.

(Example 2)
Instead of 1000 g of prepolymer (1) of component A in Example 1, 1000 g of prepolymer (2) was used as component A, and the content of MOCA of component B was changed from 286 g to 261 g. A urethane sheet was prepared in the same manner as in 1 to obtain a polishing pad.
In the mixture of components 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 number) is 0.9.

(Example 3)
A urethane sheet was prepared and a polishing pad was obtained in the same manner as in Example 1, except that 1000 g of prepolymer (3) was used as component A in place of 1000 g of prepolymer (1) of component A in Example 1. rice field.
In the mixture of components 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 number) is 0.9.

(Comparative example 1)
Same as Example 1, except that 1000 g of Adiprene L325 was used as component A in place of 1000 g of prepolymer (1) as component A in Example 1, and the content of MOCA in component B was changed from 286 g to 261 g. Then, a urethane sheet was produced to obtain a polishing pad.
In the mixture of components 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 number) is 0.9.

(Comparative example 2)
Example 1 was repeated except that 1000 g of DC6912 was used as component A in place of 1000 g of prepolymer (1) as component A in Example 1, and the content of MOCA in component B was changed from 286 g to 223 g. A urethane sheet was prepared to obtain a polishing pad.
In the mixture of components 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 number) is 0.9.

(Gel permeation chromatography (GPC) measurement of isocyanate-terminated urethane prepolymer)
(Method for preparing sample)
5 g each of the isocyanate-terminated urethane prepolymers (prepolymers (1) and (2), adiprene L325, or DC6912) used in Examples 1 and 2 and Comparative Examples 1 and 2 were collected in a container, and the container contained methanol. 5 ml of N,N-dimethylformamide (DMF) solution (concentration of methanol: 33% by weight) was added to obtain a mixture of prepolymer, methanol and DMF. The mixture in the container was stirred while being heated at a temperature of 60° C. for 1 hour to allow the methanol and the isocyanate groups of the prepolymer to react and sufficiently block (deactivate) the isocyanate groups. After deactivating the isocyanate groups, the container containing the mixed solution was allowed to stand overnight at room temperature (about 25°C) and allowed to cool. After allowing to cool, 5 ml of a DMF solution with a lithium bromide concentration of 10 mM (mmol/L) was added to the mixed liquid in the container and stirred. From the container, 0.4 mL of the mixed solution after stirring was collected, transferred to another container, a lithium bromide concentration: 5 mM DMF solution was added to the container, and the solution was added so that the final concentration was about 1% by weight. prepared. 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.
(Measuring method)
For each sample obtained as described above, molecular weight distribution in terms of polyethylene glycol/polyethylene oxide (PEG/PEO) was measured by GPC measurement under the following measurement conditions. The peak present in the molecular weight region of 200 to 400 is peak 1, the peak present in the molecular weight region of 400 to 700 is peak 2, the peak present in the molecular weight region of 700 to 10000 is peak 3, and the number average molecular weight of the entire molecular weight distribution. and weight average molecular weight, and the number average molecular weight, weight average molecular weight, peak top, and abundance ratio of each of peaks 1 to 3 were measured. The measurement results are shown in Table 1 and FIG.
(Measurement condition)
Column: 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

In Table 1 and FIG. 3, the peak (peak 1) present in the molecular weight region of 200 to 400 is derived from unreacted (free) 2,4-tolylene diisocyanate and is present in the molecular weight region of 400 to 700. (Peak 2) originates from a component formed by adding two molecules of 2,4-tolylene diisocyanate to both ends of one molecule of low-molecular-weight polyol (diethylene glycol) in the prepolymer, and is in the molecular weight region of 700 to 10,000. The existing peak (peak 3) is formed by adding 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 an ultra-high molecular weight component formed by adding 3 or more molecules of 2,4-tolylene diisocyanate to 2 or more molecules of high molecular weight polyol (polyether polycarbonate diol or polytetramethylene ether glycol) in the prepolymer. It is considered that each is derived from
From the results in Table 1, for the isocyanate-terminated urethane prepolymers (prepolymers (1) and (2)) used in Examples 1 and 2, the number average molecular weight of the entire molecular weight distribution of the prepolymer was Mna or less, and peak 3 was found to be Mna+1000 or less (Mna is the number average molecular weight of the polyether polycarbonate diol).
Further, when the same GPC measurement was performed on the isocyanate-terminated urethane prepolymer (prepolymer (3)) used in Example 3, as in Examples 1 and 2, the number average molecular weight of the entire molecular weight distribution of the prepolymer was Mna and the peak top molecular weight of peak 3 is considered to be Mna+1000 or less (Mna is the number average molecular weight of the polyether polycarbonate diol).

(Evaluation method)
The polishing pads of Examples 1 and 2 and Comparative Examples 1 and 2 were evaluated for (1) step elimination performance and (2) defects as follows.

(1) Ability to Eliminate Level Differences Each polishing pad was placed at a predetermined position in a polishing apparatus via a double-faced tape having an acrylic adhesive, and subjected to polishing under the conditions shown in <Polishing Conditions> below. Then, after polishing, the step elimination performance was evaluated by measuring with a fine shape measuring device (manufactured by KLA-Tencor, P-16+OF). Evaluation results for each polishing pad are shown in Table 2 and FIGS.
<Measurement procedure/conditions>
In this example and comparative example, a pattern wafer (insulating film: Si(OC ₂ H ₅ ) ₄ film) having a Cu film thickness of about 7000 Å, steps of 3000 to 3300 Å, and different wiring widths was used. Using a polishing pad, polishing was performed by adjusting the polishing rate so that the polishing amount was about 1000 Å at one time. The step measurement was performed for each wiring width portion on the pattern wafer.
The graph of FIG. 4(a) shows the case of polishing a wiring with a Cu wiring width of 120 μm and an insulating film of a width of 120 μm, and the graph of FIG. FIG. 5(c) shows the result of polishing a Cu wiring width of 50 μm and an insulating film width of 50 μm, and FIG. 5(d) shows the result of polishing a Cu wiring width of 10 μm and an insulating film width of 10 μm. show. The smaller the wiring width value, the finer the wiring.

<Polishing conditions>
Grinding machine used: F-REX300X (manufactured by Ebara Corporation)
Disk: A188 (manufactured by 3M)
Abrasive temperature: 20°C
Polishing surface plate rotation speed: 90 rpm
Polishing head rotation speed: 81 rpm
Polishing pressure: 3.5 psi
Polishing slurry: CSL-9044C (CSL-9044C undiluted solution:pure water = using a mixture of 1:9 weight ratio) (manufactured by Fujifilm Planar Solutions)
Polishing slurry flow rate: 200 ml/min
Polishing time: 60 seconds Objects to be polished: (Step elimination performance) each pattern wafer described above, (defective) Cu film substrate Pad break: 32N 10 minutes Conditioning: in-situ 18N 16 scans, Ex-situ 35N 4 scans

(2) Defect Each polishing pad is placed at a predetermined position in the polishing apparatus via double-sided tape having an acrylic adhesive, and the Cu film substrate (12-inch diameter disk) is placed on the Cu film substrate (12-inch diameter disk). Polishing was performed under the conditions shown in <Polishing conditions> in Performance.
The 16th, 26th, and 51st polished Cu film substrates were measured in the high-sensitivity measurement mode of a surface inspection device (Surfscan SP2XP, manufactured by KLA-Tencor), and microscratches (0 The number of fine dent-like scratches of 2 μm or more and 10 μm or less was observed, and the total was obtained. Evaluation results are shown in Table 3 and FIG.
If the number of micro-scratches is 5 or less, it can be said that the defect is small and good.

The polishing pads of Examples 1 and 2 use a polyol of number average molecular weight Mna with carbonate groups in the molecule and relate to isocyanate-terminated urethane prepolymers having a number average molecular weight of Mna or less. On the other hand, the polishing pads of Comparative Examples 1 and 2 relate to isocyanate-terminated urethane prepolymers that do not use polyols having carbonate groups in their molecules. In the polishing pads of Examples 1 and 2, the number average molecular weight of the isocyanate-terminated urethane prepolymer used was Mna or less, and the uniformity was excellent.

From the results in Tables 2 and 3 and FIGS. 4 to 6, the polishing pads of Examples 1 and 2 are superior to the polishing pads of Comparative Examples 1 and 2 in the step elimination performance in any wiring width, and scratch was greatly reduced, and it was found that the occurrence of defects could be suppressed. This tendency is considered to be the same in Example 3 as well.
As described above, a polishing pad formed from an isocyanate-terminated urethane prepolymer having a number average molecular weight of Mna or less using a polyol having a number average molecular weight Mna having a carbonate group in the molecule has excellent uniformity, and more significantly carbonate It was found that the characteristics of the base can be expressed, and as a result, dishing during polishing can be suppressed (excellent step elimination performance), and the occurrence of defects can be suppressed.

Claims (14)

A polishing pad having a polishing layer containing a polyurethane resin,
The polyurethane resin is a cured product of a curable resin composition containing 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 comprises a high molecular weight polyol,
The high molecular weight polyol contains a polyol having a carbonate group in the molecule and a number average molecular weight of Mna,
The polishing pad, wherein the isocyanate-terminated urethane prepolymer has a number average molecular weight of Mna or less. In the polyethylene glycol/polyethylene oxide (PEG/PEO)-equivalent molecular weight distribution of the isocyanate-terminated urethane prepolymer measured by gel permeation chromatography (GPC), the peak top molecular weight of the peak present in the molecular weight region of 700 to 10,000 is The polishing pad according to claim 1, which is Mna+1000 or less. 3. The polishing pad according to claim 1, wherein the polyol having a carbonate group in its molecule has a number average molecular weight Mna of 500 to 2,500. The polishing pad according to any one of claims 1 to 3, wherein the isocyanate-terminated urethane prepolymer has a number average molecular weight of 3,500 or less. 5. The polishing pad of claim 4, wherein the isocyanate-terminated urethane prepolymer has a number average molecular weight of 2000 or less. The polishing pad according to any one of claims 1 to 5, wherein the polyol having a carbonate group in its molecule contains a structural unit derived from polytetramethylene ether glycol. The polishing pad according to any one of claims 1 to 6, wherein the polyol having a carbonate group in the molecule includes a polyether polycarbonate diol represented by the following formula (I):

(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 0.1-20. ). 8. The polishing pad according to claim 7, wherein R ¹ in formula (I) is at least one selected from the group consisting of ethylene, isopropylene, and n-butylene. The polishing pad of any one of claims 1-8, wherein the high molecular weight polyol further comprises a polyether polyol. The polishing pad of any one of claims 1-9, wherein the polyisocyanate component comprises tolylene diisocyanate. The polishing pad of any one of claims 1-10, wherein the curing agent comprises 3,3'-dichloro-4,4'-diaminodiphenylmethane. The polishing pad according to any one of claims 1 to 11, wherein the curable resin composition further comprises hollow microspheres. A method of manufacturing a polishing pad according to any one of claims 1 to 12, comprising shaping the polishing layer. A method of polishing the surface of an optical or semiconductor material, comprising the step of polishing the surface of an optical or semiconductor material using a polishing pad according to any one of claims 1-12. .

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