JP2020157414A - Polishing pad, method for producing polishing pad and method for polishing surface of optical material or semiconductor material - Google Patents

Abstract

To provide a polishing pad where a non-MOCA-based curing agent is used and a time from the supply start of a slurry to stabilization in a high polishing rate level is short.SOLUTION: In a polishing pad having a polishing layer containing a polyurethane resin, the polyurethane resin is the cured product of a curable resin composition containing an isocyanate terminal urethane prepolymer and a curing agent; the curing agent contains an amine-based curing agent expressed as formula (I). (In formula (I), A is a direct coupling or divalent group; R1 and R2 are each independently hydrogen atom and alkyl, aralkyl, aryl, heteroaryl, cycloalkyl and heterocycloalkyl which each may be substituted; and n is an integer of 0 or more.)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 an optical material or a semiconductor material. 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, glass substrates for liquid crystals, and semiconductor devices are required to have extremely precise flatness. A hard polishing pad is generally used to polish the surface of such various materials flatly.

In polishing using a hard polishing pad, a slurry (abrasive liquid) is supplied on the polishing pad, and polishing is performed in a state where the slurry exists between the object to be polished and the polishing pad. The slurry is obtained by dispersing abrasive grains in pure water and adding a chemical solution according to the application. If the polishing pad and the slurry are well-adapted and the polishing pad can hold the slurry quickly, the polishing start-up time (the time from the start of the supply of the slurry to the stabilization at a high polishing rate) becomes short. More efficient polishing becomes possible. However, in the conventional polishing pad, the polishing pad and the slurry are not well-matched, and the polishing start-up time may become long.

Further, at present, many hard polishing pads have a polyurethane composition in which polyamines or polyols as a curing agent and a foaming agent / catalyst as an additive are mixed with a urethane prepolymer which is a reaction product of a polyol component and an isocyanate component. It is manufactured by a so-called prepolymer method in which a product is manufactured and the polyurethane composition is cured. As the curing agent, 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), which is an aromatic diamine, is used because it is easy to handle and the resulting polyurethane composition has excellent dynamic performance. Most commonly used.

However, since the above MOCA is suspected to be a carcinogenic substance and is a chlorine compound, it may induce the generation of dioxin, which is highly toxic at the time of incineration, and may generate acid gas. Therefore, MOCA has been pointed out as a substance harmful to the human body and the environment. Under these circumstances, it is desired to use a curing agent as an alternative to MOCA.

Patent Document 1 discloses a polishing pad manufactured by using bis- (alkylthio) aromatic diamine or the like in combination with an aliphatic triol as a non-MOCA-based curing agent.

Special Table 2010-538461A

As described above, a polishing pad manufactured by using a non-MOCA-based curing agent and having a shorter polishing rise time than a conventional polishing pad is desired.

The present invention is manufactured using a non-MOCA-based curing agent, and has a shorter polishing rise time (time from the start of supply of the slurry to stabilization at a high polishing rate) than the conventional polishing pad. It is an object of the present invention to provide a pad, a method for manufacturing the polishing pad, and a method for polishing the surface of an optical material or a semiconductor material using the polishing pad.

As a result of diligent research to solve the above problems, the present inventors have found that the above problems can be solved by using a specific amine-based curing agent instead of MOCA as the curing agent, and have completed the present invention. It was. Specific embodiments of the present invention are as follows.
In addition, in this specification, when the numerical value range is expressed by using "~", the range shall include the numerical value at both ends.

（上記式（Ｉ）中、
Ａは、直接結合又は２価の基であり、
Ｒ_１及びＲ_２は、それぞれ独立して、水素原子、置換されていてもよいアルキル、置換されていてもよいアラルキル、置換されていてもよいアリール、置換されていてもよいヘテロアリール、置換されていてもよいシクロアルキル、又は置換されていてもよいヘテロシクロアルキルであり、
ｎは０以上の整数である。）
[２] Ａが直接結合、置換されていてもよいアルキレン、置換されていてもよいオキシアルキレン、置換されていてもよいアリーレン、スルホニル、スルフィニル、カルボニル、オキシカルボニル、酸素原子、又は硫黄原子である、[１]に記載の研磨パッド。
[３] Ａが直接結合、ジメチルメチレン、又はスルホニルであり、
Ｒ_１が水素原子又はメチル基であり、Ｒ_２が水素原子であり、
ｎが０又は１である、
[１]又は[２]に記載の研磨パッド。
[４] 前記式（Ｉ）で表されるアミン系硬化剤が、３，３’−ジヒドロキシ−４，４’−ジアミノビフェニル、２，２−ビス（３−アミノ−４−ヒドロキシフェニル）プロパン、３，３’−ジアミノ−４，４’−ジヒドロキシジフェニルスルホン、２，６−ジアミノ−４−メチルフェノール、及びこれらの組み合わせからなる群から選択される、[１]〜[３]のいずれか１つに記載の研磨パッド。
[５] 前記イソシアネート末端ウレタンプレポリマーのＮＣＯのモル数に対する、前記硬化剤のＮＨ_２のモル数の比率（ＮＨ_２のモル数／ＮＣＯのモル数）が０．６〜１．２である、[１]〜[４]のいずれか１つに記載の研磨パッド。
[６] 前記イソシアネート末端ウレタンプレポリマーが、ポリオール成分とポリイソシアネート成分との反応生成物である、[１]〜[５]のいずれか１つに記載の研磨パッド。
[７] 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、[６]に記載の研磨パッド。
[８] 前記ポリオール成分がポリテトラメチレンエーテルグリコールを含む、[６]又は[７]に記載の研磨パッド。
[９] 前記硬化性樹脂組成物が微小中空球体をさらに含む、[１]〜[８]のいずれか１つに記載の研磨パッド。
[１０] [１]〜[９]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。
[１１] 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]〜[９]のいずれか１つに記載の研磨パッドを使用する、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 curing agent contains an amine-based curing agent represented by the following formula (I). ..

(In the above formula (I),
A is a direct bond or a divalent group,
R ₁ and R ₂ are independently hydrogen atom, optionally substituted alkyl, optionally substituted aralkyl, optionally substituted aryl, optionally substituted heteroaryl, substituted, respectively. Cycloalkyl which may be, or heterocycloalkyl which may be substituted,
n is an integer greater than or equal to 0. )
[2] A is a direct bond, optionally substituted alkylene, optionally substituted oxyalkylene, optionally substituted arylene, sulfonyl, sulfinyl, carbonyl, oxycarbonyl, oxygen atom, or sulfur atom. , [1].
[3] A is a direct bond, dimethylmethylene, or sulfonyl,
R ₁ is a hydrogen atom or a methyl group, R ₂ is a hydrogen atom,
n is 0 or 1,
The polishing pad according to [1] or [2].
[4] The amine-based curing agent represented by the formula (I) is 3,3'-dihydroxy-4,4'-diaminobiphenyl, 2,2-bis (3-amino-4-hydroxyphenyl) propane, and the like. Any one of [1] to [3] selected from the group consisting of 3,3'-diamino-4,4'-dihydroxydiphenylsulfone, 2,6-diamino-4-methylphenol, and combinations thereof. The polishing pad described in 1.
[5] to the number of moles of NCO of the isocyanate-terminated urethane prepolymer, the ratio of moles of NH ₂ of said curing agent (number of moles / NCO of NH ₂₎ is 0.6 to 1.2, The polishing pad according to any one of [1] to [4].
[6] The polishing pad according to any one of [1] to [5], wherein the isocyanate-terminated urethane prepolymer is a reaction product of a polyol component and a polyisocyanate component.
[7] The polishing pad according to [6], wherein the polyisocyanate component contains tolylene diisocyanate.
[8] The polishing pad according to [6] or [7], wherein the polyol component contains polytetramethylene ether glycol.
[9] The polishing pad according to any one of [1] to [8], wherein the curable resin composition further contains microhollow spheres.
[10] The method for manufacturing a polishing pad according to any one of [1] to [9].
The method comprising molding the polishing layer.
[11] The method for polishing the surface of an optical material or a semiconductor material, wherein the polishing pad according to any one of [1] to [9] is used.

Since the polishing pad of the present invention is manufactured by using a non-MOCA-based curing agent, it has less influence on the human body and the environment, and the polishing start-up time is shorter than that of the conventional polishing pad.

(Action)
In the present invention, as the curing agent, an amine-based curing agent represented by the above formula (I) is used instead of the conventionally used MOCA.

Unexpectedly, by using the amine-based curing agent represented by the above formula (I), the present inventors can obtain a polishing pad having a shorter polishing rise time than the conventional polishing pad using MOCA. I found that. The details of the reason why such characteristics are obtained are not clear, but it is presumed as follows.

The amine-based curing agent has two or more amino groups and one or more hydroxyl groups in the molecule. In general, the amino group is much more reactive than the hydroxyl group with respect to the reaction with the isocyanate group of the isocyanate-terminated urethane prepolymer. Therefore, even in the reaction between the amine-based curing agent and the isocyanate group of the isocyanate-terminated urethane prepolymer, the amino group reacts preferentially, and the hydroxyl group remains unreacted in the cured layer. Conceivable.

On the other hand, since the main component of the slurry is pure water, it is considered that the slurry tends to be attracted to and easily adapted to the hydrophilic material. Since the above-mentioned hydroxyl group has high hydrophilicity, the polishing pad (polishing layer) having an unreacted hydroxyl group produced by using the amine-based curing agent is a conventional polishing pad having no unreacted hydroxyl group (polishing layer). It is thought that the compatibility with the slurry will be better than that of the polishing layer), and as a result, the rising time of polishing will be shortened.

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

(Abrasion pad, manufacturing method of polishing pad)
The polishing pad of the present invention is a polishing pad having a polishing layer containing a polyurethane resin, wherein the polyurethane resin is a cured product of a curable resin composition containing an isocyanate-terminated urethane prepolymer and a curing agent, and the curing agent. Includes an amine-based curing agent represented by the above formula (I).

The polishing pad of the present invention has a polishing layer containing a polyurethane resin. The polishing layer is arranged at a position in direct contact with the material to be polished, and the other portion of the polishing pad may be composed 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 used as the polishing pad.

The polishing pad of the present invention has no significant difference in shape from a general polishing pad, except that the polishing rise time is short due to its good compatibility with the slurry, and it should be used in the same manner as a general polishing pad. For example, the polishing layer can be pressed against the material to be polished while rotating the polishing pad for polishing, or the material to be polished can be pressed against the polishing layer for polishing while rotating.

The polishing pad of the present invention can be produced by a generally known manufacturing method such as molding or slab molding. First, a polyurethane block is formed by these manufacturing methods, the block is made into a sheet by slicing or the like, a polishing layer formed of a polyurethane resin is formed, and the block is bonded to a support or the like. Alternatively, the polishing layer can be formed directly on the support.

More specifically, the polishing layer has a double-sided tape attached to the surface side of the polishing layer opposite to the polishing surface, and is cut into a predetermined shape to obtain the polishing pad of the present invention. The double-sided tape is not particularly limited, and can be arbitrarily selected and used from the double-sided tapes known in the art. Further, the polishing pad of the present invention may have a single-layer structure consisting of only a polishing layer, and is a multi-layer in which another layer (lower layer, support layer) is bonded to the surface side of the polishing layer opposite to the polishing surface. It may consist of.

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 made of a foamed polyurethane resin, but foaming can be performed by dispersing a foaming agent containing microhollow spheres in the polyurethane resin. In this case, a curable resin composition containing an isocyanate-terminated urethane prepolymer, a curing agent, and a foaming agent can be prepared, and the curable resin composition can be formed by foaming and curing.
The curable resin composition may be, for example, a two-component composition prepared by mixing solution A containing an isocyanate-terminated urethane prepolymer and solution B containing a curing agent component. The other components may be contained in solution A or solution B, but if a problem occurs, the composition is further divided into a plurality of solutions and mixed with three or more solutions to obtain a composition. be able to.

(Hardener)
A in the amine-based curing agent represented by the formula (I) is a direct bond or a divalent group, and when A is a divalent group, preferably an optionally substituted alkylene, substituted. It may be an oxyalkylene, optionally an arylene, a sulfonyl, a sulfinyl, a carbonyl, an oxycarbonyl, an oxygen atom, or a sulfur atom. When A is an optionally substituted alkylene, it is preferably an optionally substituted C _{1 to} C ₁₀ alkylene, more preferably C substituted by two or more C _{1 to} C ₃ alkyl. is an alkylene of _{1 ~C 8.} Of these, those in which A is a direct bond, dimethyl methylene, or sulfonyl are most preferable.

R ₁ and R ₂ in the formula (I) are independently hydrogen atom, optionally substituted alkyl, optionally substituted aralkyl, optionally substituted aryl, and optionally substituted, respectively. A good heteroaryl, a optionally substituted cycloalkyl, or a optionally substituted heterocycloalkyl. In the case of an alkyl in which A may be substituted, it is preferably an alkyl of (unsubstituted) C _{1 to} C ₅ , and more preferably an alkyl of (unsubstituted) C _{1 to} C ₃ . Of these, those in which R ₁ is a hydrogen atom or a methyl group and R ₂ is a hydrogen atom are most preferable.

N in the formula (I) is an integer of 0 or more, preferably an integer of 0 to 5, more preferably an integer of 0 to 3, and most preferably 0 or 1.

The specific compound represented by the amine-based curing agent represented by the formula (I) is not particularly limited, but is represented by 3,3'-dihydroxy-4,4'-diaminobiphenyl (represented by the following formula (II)). Compound), 2,2-bis (3-amino-4-hydroxyphenyl) propane (compound represented by the following formula (III)), 3,3'-diamino-4,4'-dihydroxydiphenylsulfone (below) It is preferable to select from the group consisting of (a compound represented by the formula (IV)), 2,6-diamino-4-methylphenol (a compound represented by the following formula (V)), and a combination thereof. ..

The curing agent may be composed of only the amine-based curing agent represented by the formula (I).
The content of the amine-based curing agent represented by the formula (I) in the entire curing agent is preferably 50 to 100% by weight, more preferably 70 to 100% by weight, and most preferably 80 to 100% by weight. When the content of the amine-based curing agent is within the above numerical range, a polishing pad having a short polishing rise time can be obtained.

To the number of moles of NCO isocyanate-terminated urethane prepolymer, the ratio of moles of NH ₂ curing agent (number of moles / NCO of NH ₂₎ is preferably from 0.6 to 1.2, 0.7 1.0 is more preferable, and 0.80 to 0.95 is most preferable. When the value of the number of moles of NH ₂ / the number of moles of NCO is within the above range, some or all of the hydroxyl groups in the curing agent are likely to remain as unreacted groups in the polishing layer of the polishing pad. As a result, the hydrophilicity of the polishing layer is increased, the compatibility with the slurry is improved, and the rising time of polishing is shortened.

The curing agent may further contain a curing agent other than the amine-based curing agent represented by the formula (I), and examples of such a curing agent include amine-based curing agents and polyol-based curing agents. ..
Examples of the polyamine constituting the amine-based curing agent include diamines, which include alkylenediamines such as ethylenediamine, propylenediamine and hexamethylenediamine; and fats such as isophoronediamine and dicyclohexylmethane-4,4'-diamine. Diamine having a group ring; Diamine having an aromatic ring such as 3,3'-dichloro-4,4'-diaminodiphenylmethane (also known as methylenebis-o-chloroaniline) (hereinafter abbreviated as MOCA); 2- Diamines having hydroxyl groups such as hydroxyethylethylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2-hydroxypropylethylenediamine, especially hydroxy Alkylalkylenediamine; and the like. In addition, trifunctional triamine compounds and tetrafunctional or higher functional polyamine compounds can also be used.
Examples of the polyol curing agent include compounds described later as the polyol component of the isocyanate-terminated urethane prepolymer.

The curing agent may or may not contain the above-mentioned MOCA.
When the curing agent contains MOCA, its content with respect to the entire curing agent is preferably more than 0% by weight and less than 50% by weight, more preferably more than 0% by weight and less than 30% by weight, and more than 0% by weight and 20% by weight. Less than is most preferred. Further, here, "not containing 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA)" means that it is not contained as an intentional additive, and is a case where it is contained as an impurity. Also, 0.1% by mass or less is preferable, 0.05% by mass or less is more preferable, and 0.01% by mass or less is most preferable with respect to the whole curing agent. When the content of MOCA is within the above numerical range, a polishing pad having less influence on the human body and the environment can be obtained.

(Isocyanate-terminated urethane prepolymer)
The isocyanate-terminated urethane prepolymer is preferably a product obtained by reacting a polyol component with a polyisocyanate component.

The NCO equivalent (g / eq) of the isocyanate-terminated urethane prepolymer is preferably less than 600, more preferably 350 to 550, and most preferably 400 to 500. When the NCO equivalent (g / eq) is within the above numerical range, a polishing pad having appropriate polishing performance can be obtained, and when the NCO equivalent (g / eq) is less than 350, the hardness of the obtained polishing pad becomes large and is defective. It is not preferable because the performance is deteriorated. Further, when the NCO equivalent (g / eq) exceeds 500, the hardness of the obtained polishing pad becomes small and the flattening performance tends to deteriorate, which is not preferable. The NCO equivalent is "(mass part of polyisocyanate compound + mass part of polyol compound) / [(number of functional groups per molecule of polyisocyanate compound x mass part of polyisocyanate compound / molecular weight of polyisocyanate compound)-(polyxylate compound). The number of functional groups per molecule of the compound x the mass part of the polyol compound / the molecular weight of the polyol compound)] ”is a numerical value indicating the molecular weight of PP (prepolymer) per NCO group.

(Polyol component)
As a polyol component contained in the isocyanate-terminated urethane prepolymer,
For example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentandiol, 3-methyl- Diols such as 1,5-pentanediol and 1,6-hexanediol;
Polyether polyols such as polytetramethylene ether glycol (PTMG), polyethylene glycol, polypropylene glycol;
Polyester polyols such as a reaction product of ethylene glycol and adipic acid and a reaction product of butylene glycol and adipic acid;
Polycarbonate polyol;
Polycaprolactone polyol; etc.
Among these, it is preferable to use polytetramethylene ether glycol from the viewpoint of the handleability of the prepolymer and the mechanical strength of the obtained polishing pad. The number average molecular weight of polyoxytetramethylene glycol is preferably 500 to 2000, more preferably 600 to 1000, and most preferably 650 to 850.

(Polyisocyanate component)
As a polyisocyanate component contained in the isocyanate-terminated urethane prepolymer,
For example, m-phenylenediocyanate,
p-phenylene diisocyanate,
2,6-Toluene diisocyanate (2,6-TDI),
2,4-Toluene diisocyanate (2,4-TDI),
Naphthalene-1,4-diisocyanate,
Diphenylmethane-4,4'-diisocyanate (MDI),
4,4'-Methylene-bis (cyclohexyl isocyanate) (hydrogenated MDI),
3,3'-dimethoxy-4,4'-biphenyldiisocyanate,
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-Phenylisothiocyanate,
Xylylene-1,4-diisothiocyanate,
Ethilidine diisothiocyanate and the like can be mentioned.
Among these, 2,6-toluene diisocyanate (2,6-TDI), 2,4-toluene diisocyanate (2,4-TDI) and the like are used from the viewpoint of the polishing characteristics and mechanical strength of the obtained polishing pad. It is preferable to use tolylene diisocyanate.

(Micro hollow sphere)
In the present invention, the curable resin composition can further contain microhollow spheres.
A foam can be formed by mixing the fine hollow spheres with the polyurethane resin. The microhollow sphere refers to an unexpanded heat-expandable microsphere composed of an outer shell (polymer shell) made of a thermoplastic resin and a low boiling point hydrocarbon contained in the outer shell, which is heated and expanded. .. As the polymer shell, for example, a thermoplastic resin such as an acrylonitrile-vinylidene chloride copolymer, an acrylonitrile-methylmethacrylate copolymer, or a vinyl chloride-ethylene copolymer can be used. Similarly, as the low boiling point hydrocarbon contained in the polymer shell, for example, isobutane, pentane, isopentane, petroleum ether and the like can be used.

(Other ingredients)
In addition, a catalyst generally used in the art may be added to the curable resin composition.
Further, the above-mentioned polyisocyanate component can be additionally added to the curable resin composition later, and the weight ratio of the additional polyisocyanate component to the total weight of the isocyanate-terminated urethane prepolymer and the additional polyisocyanate component can be determined. 0.1 to 10% by weight is preferable, 0.5 to 8% by weight is more preferable, and 1 to 5% by weight is particularly preferable.
As the polyisocyanate component to be additionally added to the polyurethane resin curable composition, the above-mentioned polyisocyanate component can be used without particular limitation, but 4,4'-methylene-bis (cyclohexylisocyanate) (hydrogenated MDI) Is preferable.

(Method of polishing the surface of optical material or semiconductor material)
In the present invention, the surface of the optical material or the semiconductor material is polished by using the above-mentioned polishing pad.
The method of polishing the surface of an optical material or a semiconductor material of the present invention can further include a step of supplying a slurry to the surface of a polishing pad, the surface of the optical material or the semiconductor material, or both of them.

(slurry)
The liquid component contained in the slurry is not particularly limited, and examples thereof include water (pure water), acid, alkali, and an organic solvent, which are selected depending on the material of the object to be polished, desired polishing conditions, and the like. 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. The abrasive grain component contained in the slurry is not particularly limited, and examples thereof include silica, zirconium silicate, cerium oxide, aluminum oxide, and manganese oxide. The slurry may contain other components such as an organic substance soluble in a liquid component and a pH adjuster.

The present invention will be described experimentally with the following examples, but the following description is not intended to be construed as limiting the scope of the invention to the following examples.

(material)
The materials used in the following examples are listed.

・ Isocyanate-terminated urethane prepolymer:
Prepolymer (1): A urethane prepolymer having an NCO equivalent of 454 containing tolylene diisocyanate as a polyisocyanate component, polytetramethylene ether glycol having a number average molecular weight of 650 and diethylene glycol as a polyol component.

・ Hardener:
Amine-based curing agent (1) ... 3,3'-dihydroxy-4,4'-diaminobiphenyl (compound represented by the above formula ((II)) (NH ₂ equivalent = 108.1))
Amine-based curing agent (2) ... 2,2-bis (3-amino-4-hydroxyphenyl) propane (compound represented by the above formula ((III))) (NH ₂ equivalent = 129.2)
Amine-based curing agent (3) ... 3,3'-diamino-4,4'-dihydroxydiphenylsulfone (compound represented by the above formula ((IV)) (NH ₂ equivalent = 140.2)
Amine-based curing agent (4) ... 2,6-diamino-4-methylphenol (compound represented by the above formula ((V))) (NH ₂ equivalent = 69.1)
MOCA: 3,3'-dichloro-4,4'-diaminodiphenylmethane (also known as methylenebis-o-chloroaniline) (NH ₂ equivalent = 133.5)

・ Micro hollow sphere:
EXPANCEL 551DE40d42 (manufactured by Nippon Phillight Co., Ltd.)

(Example 1)
100 g of the prepolymer (1) was prepared as the A component, 21.4 g of the amine-based curing agent (1) as the curing agent as the B component, and 2 g of the micro hollow sphere (EXPANCEL 551DE40d42) as the C component. Incidentally, to the number of moles of NCO of the prepolymer of component A, the ratio of moles of NH ₂ amine curing agent component B (the NH ₂ moles / moles of NCO) is 0.9. In addition, it is described as g display to indicate the ratio, and the required weight (part) is prepared according to the size of the block. Hereinafter, it is described in g (part) notation in the same manner.
It is considered that almost all NH ₂ of the amine-based curing agent (1) reacts with the NCO of the prepolymer, while OH of the amine-based curing agent (1) partially reacts with the NCO of the prepolymer. It is considered that it exists unreacted. Amine-based curing agent (1) Since there are two OHs per molecule, the unreacted OH is considered to be about 0.099 × 2 × Avogadro constant (pieces).
After mixing the A component and the C component and defoaming the mixture of the A component and the C component under reduced pressure, the mixture of the A component and the C component and the B component were supplied to the mixer.
The obtained mixed solution was cast into a mold heated to 80 ° C., heated for 1 hour to cure, and then the formed resin foam was extracted from the mold and then cured at 120 ° C. for 5 hours. This foam was sliced to a thickness of 1.3 mm to prepare a urethane sheet, and a polishing pad was obtained.

(Example 2)
25.6 g of an amine-based curing agent (2) was prepared in place of 21.4 g of the amine-based curing agent (1) of the B component of Example 1. Incidentally, to the number of moles of NCO of the prepolymer of component A, the ratio of moles of NH ₂ amine curing agent component B (the NH ₂ moles / moles of NCO) is 0.9. Similar to Example 1, it is considered that the OH of the amine-based curing agent (2) remains almost unreacted. The unreacted OH of the amine-based curing agent (2) is considered to be about 0.099 × 2 × Avogadro constant (pieces) because there are two OHs per molecule of the amine-based curing agent (2).
After that, a urethane sheet was prepared in the same manner as in Example 1 to obtain a polishing pad.

(Example 3)
Instead of 21.4 g of the amine-based curing agent (1) of the B component of Example 1, 27.8 g of the amine-based curing agent (3) was prepared. Incidentally, to the number of moles of NCO of the prepolymer of component A, the ratio of moles of NH ₂ amine curing agent component B (the NH ₂ moles / moles of NCO) is 0.9. Similar to Example 1, it is considered that the OH of the amine-based curing agent (3) remains almost unreacted. The unreacted OH of the amine-based curing agent (3) is considered to be about 0.099 × 2 × Avogadro constant (pieces) because there are two OHs per molecule of the amine-based curing agent (3).
After that, a urethane sheet was prepared in the same manner as in Example 1 to obtain a polishing pad.

(Example 4)
In place of 21.4 g of the amine-based curing agent (1) of the B component of Example 1, 13.7 g of the amine-based curing agent (4) was prepared. Incidentally, to the number of moles of NCO of the prepolymer of component A, the ratio of moles of NH ₂ amine curing agent component B (the NH ₂ moles / moles of NCO) is 0.9. Similar to Example 1, it is considered that the OH of the amine-based curing agent (4) remains almost unreacted. The unreacted OH of the amine-based curing agent (4) is considered to be about 0.099 × Avogadro constant (pieces) because there is one OH per molecule of the amine-based curing agent (4).
After that, a urethane sheet was prepared in the same manner as in Example 1 to obtain a polishing pad.

(Comparative Example 1)
26.5 g of MOCA was prepared in place of 21.4 g of the amine-based curing agent (1) of the B component of Example 1. Incidentally, to the number of moles of NCO of the prepolymer of component A, the ratio of moles of NH ₂ amine curing agent component B (the NH ₂ moles / moles of NCO) is 0.9.
After that, a urethane sheet was prepared in the same manner as in Example 1 to obtain a polishing pad. Since MOCA has no OH, unlike Examples 1 to 4, the number of unreacted OH is 0.

(Evaluation method)
The following polishing start-up performance was evaluated for each of the polishing pads of Examples 1 to 4 and Comparative Example 1.

(Evaluation of polishing start-up performance)
The evaluation of the polishing start-up performance is performed by polishing 50 substrates and determining the rate of change in the polishing rate of the 10th, 25th, and 50th substrates based on the following polishing test conditions. The rise performance was evaluated.
Specifically, first, the polishing rates (unit: Å) of the _10th , _25th, and _50th substrates (referred to as R ₁₀ , R _25, and R ₅₀ , respectively) were measured. Then, the values (%) of R ₁₀ / R ₅₀ and R ₂₅ / R ₅₀ were calculated from the obtained polishing rates, and the rising performance was evaluated based on the criteria shown in Table 1 below.

<Conditions for polishing test>
-Grinding machine used: F-REX300X manufactured by Ebara Corporation
・ Disk: 3MA188 (# 100)
-Rotation speed: (Surface plate) 70 rpm, (Top ring) 71 rpm
・ Polishing pressure: 3.5psi
-Abrasive: Made by Cabot Corporation, Part number: SS25 (SS25 stock solution: pure = 1: 1 weight ratio mixed solution is used)
・ Abrasive temperature: 20 ℃
・ Abrasive discharge rate: 200 ml / min
-Work (object to be polished): A substrate formed by PE-CVD with tetraethoxysilane on a 12-inch silicon wafer so that the thickness of the insulating film is 1 μm.-Pad break: 35N 10 minutes-Conditioning: Ex-situ, 35N, 4 scans

The results are shown in Table 2 below.

From the results in Table 2, all of Examples 1 to 4 having an unreacted hydroxyl group were superior in rising performance as compared with Comparative Example 1, and had sufficient rising performance. From the results of Examples 1 to 4, it is considered that the number of unreacted hydroxyl groups and the molecular structure that easily aggregates are related to the rising performance, and Examples of the structure that has many unreacted hydroxyl groups and is more likely to aggregate. It was found that 3 has the best rising performance.

From the above results, it was confirmed that the rising time of polishing was shorter than that of the conventional polishing pad while using a non-MOCA-based material as a curing agent.

Claims (11)

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 curing agent contains an amine-based curing agent represented by the following formula (I). ..

(In the above formula (I),
A is a direct bond or a divalent group,
R ₁ and R ₂ are independently hydrogen atom, optionally substituted alkyl, optionally substituted aralkyl, optionally substituted aryl, optionally substituted heteroaryl, substituted, respectively. Cycloalkyl which may be, or heterocycloalkyl which may be substituted,
n is an integer greater than or equal to 0. ) Claim that A is a direct bond, optionally substituted alkylene, optionally substituted oxyalkylene, optionally substituted arylene, sulfonyl, sulfinyl, carbonyl, oxycarbonyl, oxygen atom, or sulfur atom. The polishing pad according to 1. A is a direct bond, dimethylmethylene, or sulfonyl,
R ₁ is a hydrogen atom or a methyl group, R ₂ is a hydrogen atom,
n is 0 or 1,
The polishing pad according to claim 1 or 2. The amine-based curing agent represented by the formula (I) is 3,3'-dihydroxy-4,4'-diaminobiphenyl, 2,2-bis (3-amino-4-hydroxyphenyl) propane, 3,3. The polishing according to any one of claims 1 to 3, selected from the group consisting of'-diamino-4,4'-dihydroxydiphenylsulfone, 2,6-diamino-4-methylphenol, and combinations thereof. pad. To the number of moles of NCO of the isocyanate-terminated urethane prepolymer, the ratio number of moles of NH ₂ of the curing agent (moles / moles of NCO of NH ₂₎ is 0.6 to 1.2, according to claim 1 The polishing pad according to any one of 4 to 4. The polishing pad according to any one of claims 1 to 5, wherein the isocyanate-terminated urethane prepolymer is a reaction product of a polyol component and a polyisocyanate component. The polishing pad according to claim 6, wherein the polyisocyanate component contains tolylene diisocyanate. The polishing pad according to claim 6 or 7, wherein the polyol component contains polytetramethylene ether glycol. The polishing pad according to any one of claims 1 to 8, wherein the curable resin composition further contains microhollow spheres. The method for manufacturing a polishing pad according to any one of claims 1 to 9.
The method comprising molding the polishing layer. The method for polishing the surface of an optical material or a semiconductor material, wherein the polishing pad according to any one of claims 1 to 9 is used.