JP2023049623A - 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 content of the carbonate group to the whole polyol having the carbonate group in the molecule is 1.5-21.0 wt.%.SELECTED DRAWING: Figure 1

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.

The present inventors have made intensive studies to solve the above problems, and found that a polyol having a carbonate group content of 1.5 to 21.0% by weight was used as a high-molecular-weight polyol component for forming an isocyanate-terminated urethane prepolymer. The inventors have found that the above problems can be solved by using it, 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。）。
[４] 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、[３]に記載の研磨パッド。
[５] 前記分子内にカーボネート基を有するポリオールの数平均分子量が２００～５０００である、[１]～[４]のいずれか１つに記載の研磨パッド。
[６] 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]～[５]のいずれか１つに記載の研磨パッド。
[７] 前記研磨層全体に対する、前記分子内にカーボネート基を有するポリオールの前記カーボネート基の含有量が０．５～６．４重量％である、[１]～[６]のいずれか１つに記載の研磨パッド。
[８] 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]～[７]のいずれか１つに記載の研磨パッド。
[９] 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]～[８]のいずれか１つに記載の研磨パッド。
[１０] 前記硬化性樹脂組成物が微小中空球体をさらに含む、[１]～[９]のいずれか１つに記載の研磨パッド。
[１１] [１]～[１０]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。
[１２] 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]～[１０]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 contains a high-molecular-weight polyol, and the high-molecular-weight polyol contains a polyol having a carbonate group in the molecule,
The polishing pad, wherein the content of the carbonate group is 1.5 to 21.0% by weight with respect to the entire polyol having the carbonate group in the molecule.
[2] The polishing pad of [1], wherein the polyol having a carbonate group in its molecule contains a structural unit derived from polytetramethylene ether glycol.
[3] The polishing pad according to [1] or [2], wherein the polyol having a carbonate group in the molecule contains 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. ).
[4] The polishing pad of [3], wherein R ¹ in formula (I) is at least one selected from the group consisting of ethylene, isopropylene, and n-butylene.
[5] The polishing pad according to any one of [1] to [4], wherein the polyol having a carbonate group in its molecule has a number average molecular weight of 200 to 5,000.
[6] The polishing pad according to any one of [1] to [5], wherein the high molecular weight polyol further contains a polyether polyol.
[7] Any one of [1] to [6], wherein the content of the carbonate group in the polyol having a carbonate group in the molecule is 0.5 to 6.4% by weight with respect to the entire polishing layer. The polishing pad described in .
[8] The polishing pad according to any one of [1] to [7], wherein the polyisocyanate component contains tolylene diisocyanate.
[9] The polishing pad of any one of [1] to [8], wherein the curing agent contains 3,3'-dichloro-4,4'-diaminodiphenylmethane.
[10] The polishing pad according to any one of [1] to [9], wherein the curable resin composition further contains hollow microspheres.
[11] A method for manufacturing a polishing pad according to any one of [1] to [10], comprising the step of molding the polishing layer.
[12] 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 [10]. 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. (a) and (b) of FIG. 3 are graphs showing evaluation results of the step elimination performance of the polishing pads of Examples 1 and 10 and Comparative Examples 1 and 8. FIG. (c) and (d) of FIG. 4 are graphs showing evaluation results of the step elimination performance of the polishing pads of Examples 1 and 10 and Comparative Examples 1 and 8. FIG. 5 is a graph showing evaluation results of defects of the polishing pads of Examples 1 and 10 and Comparative Examples 1 and 8. FIG.

(Action)
The present inventors have conducted intensive research on the relationship between the polyol component forming the isocyanate-terminated urethane prepolymer, step elimination performance, and defects. content is 1.5 to 21.0% by weight, and by using a polyol having a carbonate group in the molecule, it is possible to obtain a polishing pad that is excellent in level difference elimination performance, can suppress dishing, and can suppress defects. I found out. 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 the molecule with a carbonate group content of 1.5 to 21.0% by weight has a moderate content of carbonate groups, so it is considered that the crystallinity is lower than that of PTMG. , the crystallinity of isocyanate-terminated urethane prepolymers formed from polyols having carbonate groups in the molecule is also considered to be low. It is thought that when the crystallinity of the isocyanate-terminated urethane prepolymer that forms the polishing layer is low, it becomes difficult for the scraps of the polishing layer generated during polishing to aggregate and form large lumps. It is presumed that the step elimination performance 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, and the high-molecular-weight polyol contains a polyol having a carbonate group in the molecule,
The content of the carbonate group is 1.5 to 21.0% by weight with respect to the entire polyol having a carbonate group in the molecule.

(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 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.
In some embodiments, the content of carbonate groups (-OC(=O)O-) is 1.5 to 21.0% by weight, and 3 to 20 It can also be weight percent, 5-19 weight percent, or 10-18 weight percent. When the carbonate group content relative to the entire polyol having a carbonate group in the molecule is within the above numerical range, a polishing pad having excellent unevenness eliminating performance, dishing and defects can be suppressed.
The content of carbonate groups with respect to the entire polyol having carbonate groups in the molecule is
{(number of carbonate groups) x (molecular weight of carbonate groups)}/(number average molecular weight of polyol having carbonate groups in the molecule) x 100 (molecular weight of carbonate groups: 60)
can be calculated as

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; ).

When the polyol having a carbonate group in the molecule is a polyether polycarbonate diol represented by the above formula (I), the content of the carbonate group with respect to the entire polyol having a carbonate group in the molecule is expressed by the following formula (1). can be calculated based on

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 of the polyol having a carbonate group in the molecule is preferably 200-5000, more preferably 500-3000, and most preferably 800-2500.

The number average molecular weight of the polyol having a structural unit derived from the polytetramethylene ether glycol and a carbonate group in the molecule was determined by gel permeation chromatography (GPC) under the following conditions: polyethylene glycol/polyethylene oxide (PEG /PEO) conversion can be measured.
<Measurement conditions>
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

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 25 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 above-mentioned low-molecular-weight polyol and the above-mentioned high-molecular-weight polyol other than the above-mentioned polyol having a carbonate group in the molecule is indicated by the number-average molecular weight of the structural unit derived from the above-mentioned polytetramethylene ether glycol and the above-mentioned polyether polycarbonate diol. can be measured by the same method as

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 45% 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.

In some embodiments, the carbonate group content of the polyol having a carbonate group in the molecule is 0.5 to 6.4% by weight, 0.75 to 6.0% by weight, based on the entire polishing layer of the polishing pad. %, or 1.5-5.5% by weight.

The carbonate group content of the polyol having a carbonate group in the molecule relative to the entire polishing layer of the polishing pad can be calculated based on the following formula (2).

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 15 and Comparative Examples 1 to 7 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. The content is 17.0% by weight.Details are shown in Table 1 below.)
PEPCD (2) to (11) .

・Isocyanate-terminated urethane prepolymer:
Prepolymers (1) to (22): Details are shown in Table 2 below.
The numerical value of each component shown in Table 2 means the weight part of each component when the whole urethane prepolymer is 1000 weight parts.
For example, prepolymer (1) shown in Table 2 contains 388 parts by weight of 2,4-tolylene diisocyanate as a polyisocyanate component, and 367 parts by weight of the above PEPCD (1) as a high molecular weight polyol component and a number average It is a urethane prepolymer having an NCO equivalent of 500 containing 184 parts by weight of polytetramethylene ether glycol having a molecular weight of 650 and 61 parts by weight of diethylene glycol as a low molecular weight polyol component. The contents of 2,4-tolylene diisocyanate, PEPCD (1), polytetramethylene ether glycol having a number average molecular weight of 650, and diethylene glycol with respect to the entire prepolymer (1) are each 38.8% by weight, 36.7 wt%, 18.4 wt%, and 6.1 wt%.

・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, 240 g of MOCA as a curing agent as component B, and 30 g of hollow microspheres (Expancel 461 DU20) 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. The obtained resin foam was sliced into a thickness of 1.3 mm to prepare a urethane sheet, and a double-faced tape was attached to the back surface of the urethane sheet to obtain a polishing pad.
Based on the formula (2) above, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 4.93% by weight with respect to the entire polishing layer.

(Example 2)
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 (2) 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 4.93% by weight with respect to the entire polishing layer based on the above formula (2).

(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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 4.93% by weight with respect to the entire polishing layer based on the above formula (2).

(Example 4)
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 (4) 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 0.91% by weight with respect to the entire polishing layer based on the above formula (2).

(Example 5)
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 (5) 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 0.91% by weight with respect to the entire polishing layer based on the above formula (2).

(Example 6)
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 (6) 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 0.91% by weight with respect to the entire polishing layer based on the above formula (2).

(Example 7)
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 (7) 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 5.98% by weight with respect to the entire polishing layer based on the above formula (2).

(Example 8)
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 (8) 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 1.83% by weight with respect to the entire polishing layer based on the above formula (2).

(Example 9)
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 (9) 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 0.89% by weight with respect to the entire polishing layer based on the above formula (2).

(Example 10)
Instead of 1000 g of prepolymer (1) of component A in Example 1, 1000 g of prepolymer (10) was used as component A, and the amount of MOCA used as component B was changed from 240 g to 286 g. A urethane sheet was prepared in the same manner as in Example 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 4.53% by weight with respect to the entire polishing layer based on the above formula (2).

(Example 11)
Instead of 1000 g of prepolymer (1) of component A in Example 1, 1000 g of prepolymer (11) was used as component A, and the amount of MOCA used as component B was changed from 240 g to 286 g. A urethane sheet was prepared in the same manner as in Example 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. Further, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 1.68% by weight with respect to the entire polishing layer based on the above formula (2).

(Example 12)
Instead of 1000 g of prepolymer (1) of component A in Example 1, 1000 g of prepolymer (12) was used as component A, and the amount of MOCA used as component B was changed from 240 g to 200 g. A urethane sheet was prepared in the same manner as in Example 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 5.27% by weight with respect to the entire polishing layer based on the above formula (2).

(Example 13)
Instead of 1000 g of prepolymer (1) of component A in Example 1, 1000 g of prepolymer (13) was used as component A, and the amount of MOCA used as component B was changed from 240 g to 200 g. A urethane sheet was prepared in the same manner as in Example 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. Further, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 1.96% by weight with respect to the entire polishing layer based on the above formula (2).

(Example 14)
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 (14) 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 1.40% by weight with respect to the entire polishing layer based on the above formula (2).

(Example 15)
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 (1) as component A in Example 1 was replaced with 1000 g of prepolymer (15) as component A. 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 2.87% by weight with respect to the entire polishing layer based on the above formula (2).

(Comparative example 1)
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 (16) 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 0.22% by weight with respect to the entire polishing layer based on the above formula (2).

(Comparative example 2)
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 (17) 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. Further, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 6.54% by weight with respect to the entire polishing layer based on the above formula (2).

(Comparative 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 (18) 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. Further, when the content of carbonate groups in polyols having carbonate groups in the molecule is calculated with respect to the entire polishing layer based on the above formula (2), it is 0% by weight (the polishing layer does not contain carbonate groups). .

(Comparative Example 4)
Instead of 1000 g of prepolymer (1) of component A in Example 1, 1000 g of prepolymer (19) was used as component A, and the amount of MOCA used as component B was changed from 240 g to 286 g. A urethane sheet was prepared in the same manner as in Example 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. Also, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 0.20% by weight with respect to the entire polishing layer based on the above formula (2).

(Comparative Example 5)
Instead of 1000 g of prepolymer (1) of component A in Example 1, 1000 g of prepolymer (20) was used as component A, and the amount of MOCA used as component B was changed from 240 g to 200 g. A urethane sheet was prepared in the same manner as in Example 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. Further, the carbonate group content of the polyol having a carbonate group in the molecule is calculated to be 0.24% by weight with respect to the entire polishing layer based on the above formula (2).

(Comparative Example 6)
Instead of 1000 g of prepolymer (1) as component A in Example 1, 1000 g of prepolymer (21) was used as component A, and the amount of MOCA used as component B was changed from 240 g to 286 g. A urethane sheet was prepared in the same manner as in Example 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. Further, when the content of carbonate groups in polyols having carbonate groups in the molecule is calculated with respect to the entire polishing layer based on the above formula (2), it is 0% by weight (the polishing layer does not contain carbonate groups). .

(Comparative Example 7)
Instead of 1000 g of prepolymer (1) of component A in Example 1, 1000 g of prepolymer (22) was used as component A, and the amount of MOCA used as component B was changed from 240 g to 200 g. A urethane sheet was prepared in the same manner as in Example 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. Further, when the content of carbonate groups in polyols having carbonate groups in the molecule is calculated with respect to the entire polishing layer based on the above formula (2), it is 0% by weight (the polishing layer does not contain carbonate groups). .

(Comparative Example 8)
As Comparative Example 8, IC1000 (manufactured by Nitta Haas Co., Ltd.), which is a conventionally known polishing pad, was prepared.

(Evaluation method)
The polishing pads of Examples 1 and 10 and Comparative Examples 1 and 8 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 3 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. 3(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. 4(c) shows the result of polishing a Cu wiring width of 50 μm and an insulating film width of 50 μm, and FIG. 4(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 4 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 1-15 relate to urethane prepolymers using polyols having a content of carbonate groups of 1.5-21.0% by weight. On the other hand, the polishing pads of Comparative Examples 1, 2, 4, and 5 relate to urethane prepolymers using polyols having a carbonate group content of less than 1.5% by weight or more than 21.0% by weight, respectively. , Comparative Examples 3, 6 and 7 relate to urethane prepolymers in which a polyol having a carbonate group was not used. Comparative Example 8 is a conventionally known polishing pad.

From the results in Tables 3 and 4 and FIGS. 3 to 5, the polishing pads of Examples 1 and 10 are superior to the polishing pads of Comparative Examples 1 and 8 in step elimination performance in any wiring width, and scratch was greatly reduced, and it was found that the occurrence of defects could be suppressed. Moreover, the polishing pad of Comparative Example 2 was poor in flexibility, elongation, and flexibility at low temperatures, and was unsuitable for polishing.
As described above, a polishing pad formed from a urethane prepolymer using a polyol having a carbonate group in its molecule and having a carbonate group content of 1.5 to 21.0% by weight can suppress dishing during polishing ( It was found to be excellent in level difference elimination performance) and to suppress the occurrence of defects.

Claims (12)

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 contains a high-molecular-weight polyol, and the high-molecular-weight polyol contains a polyol having a carbonate group in the molecule,
The polishing pad, wherein the content of the carbonate group is 1.5 to 21.0% by weight with respect to the entire polyol having the carbonate group in the molecule. 2. The polishing pad according to claim 1, wherein the polyol having a carbonate group in its molecule contains a structural unit derived from polytetramethylene ether glycol. The polishing pad according to claim 1 or 2, 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. ). 4. The polishing pad according to claim 3, wherein R ¹ in formula (I) is at least one selected from the group consisting of ethylene, isopropylene, and n-butylene. The polishing pad according to any one of claims 1 to 4, wherein the polyol having carbonate groups in the molecule has a number average molecular weight of 200 to 5,000. The polishing pad of any one of claims 1-5, wherein the high molecular weight polyol further comprises a polyether polyol. The polishing pad according to any one of claims 1 to 6, wherein the content of the carbonate group of the polyol having a carbonate group in the molecule is 0.5 to 6.4% by weight with respect to the entire polishing layer. . The polishing pad of any one of claims 1-7, wherein the polyisocyanate component comprises tolylene diisocyanate. The polishing pad of any one of claims 1-8, wherein the curing agent comprises 3,3'-dichloro-4,4'-diaminodiphenylmethane. The polishing pad according to any one of claims 1 to 9, wherein the curable resin composition further contains hollow microspheres. A method of manufacturing a polishing pad according to any one of claims 1 to 10, comprising shaping the polishing layer. A method of polishing the surface of an optical or semiconductor material, comprising polishing the surface of an optical or semiconductor material using a polishing pad according to any one of claims 1-10. .

Images