JP7072429B2 - Polishing pads, methods of manufacturing polishing pads, and methods of polishing the surface of optical or semiconductor materials. - Google Patents

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. Further, in the polishing of semiconductor devices, with the recent miniaturization and densification of integrated circuits, a stricter level of suppression of defects such as scratches and organic residues is required. It's coming. In order to polish the surface of such various materials flat, a hard polishing pad is generally used.

In polishing using a hard polishing pad, a considerable amount of polishing debris is generated at the end of one polishing operation from the start of polishing to the replacement of the polishing pad and the abrasive liquid (slurry). Due to the accumulation of polishing debris, the opening of the polishing pad is clogged, the retention of the slurry of the polishing pad deteriorates, and frictional heat is generated. Therefore, during one polishing operation, the temperature of the surface of the object to be polished rises from the initial stage to the final stage and changes in a wide temperature range including 30 ° C. to 90 ° C. Further, since the slurry used for chemical mechanical polishing has a strong chemical action (corrosion of the surface of the object to be polished) as the temperature rises, a larger scratch tends to occur at the end of one polishing operation. In such a situation where scratches are likely to occur, if the rigidity of the surface of the polishing pad is maintained high, scratches are more likely to occur on the surface of the object to be polished.

Currently, many rigid polishing pads are made by mixing a polyurethane prepolymer, which is a reaction product of a polyol component and an isocyanate component, with polyamines or polyols as a curing agent, and a foaming agent / catalyst as an additive to form a polyurethane composition. It is manufactured by a so-called prepolymer method in which the polyurethane composition is manufactured and 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 has excellent dynamic performance of the obtained polyurethane composition. Most often used.

However, since the above MOCA is suspected to be a carcinogen and is a chlorine compound, it may induce the generation of dioxin, which is extremely 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 2010-538461 Publication No.

Further, as a result of the examination by the present inventors, it was found that the polishing pad using MOCA as a curing agent has a high hardness (rigidity) and is easily scratched on the object to be polished, as shown in the comparative example described later. ..

Furthermore, the present inventors have studied the use of a polyol, which is a diol, as a curing agent in combination with MOCA for the purpose of substituting a part of MOCA. Since the reaction rate was lower than that of diamines, it was found that the diols did not react and were contained as an unreacted residue in the cured resin composition. If such an unreacted residue is present, it is considered that it adheres to the object to be polished as an organic residue during polishing and becomes a defect.

As described above, there is a demand for a polishing pad that has a lower hardness than the conventional polishing pad, generates less organic residue, and as a result can suppress the generation of defects such as scratches and organic residues.

INDUSTRIAL APPLICABILITY The present invention has a lower hardness than a conventional polishing pad, less generation of organic residue, and as a result, a polishing pad capable of suppressing the generation of defects such as scratches and organic residues, a method for manufacturing the polishing pad, and an optical material or It is an object of the present invention to provide a method for polishing the surface of a semiconductor material.

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. rice field. 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、ｎは、前記アミン系硬化剤の数平均分子量が４００～１３００となる１以上の自然数である。）
[２] 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]に記載の研磨パッド。
[３] 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、[２]に記載の研磨パッド。
[４] 前記ポリオール成分がポリオキシテトラメチレングリコールを含む、[２]又は[３]に記載の研磨パッド。
[５] 前記硬化性樹脂組成物が微小中空球体をさらに含む、[１]～[４]のいずれか１つに記載の研磨パッド。
[６] [１]～[５]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。
[７] 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]～[５]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 is an amine-based material having a number average molecular weight of 400 to 1300 represented by the following formula (I). The polishing pad containing a curing agent.

(In the above formula (I), n is a natural number of 1 or more in which the number average molecular weight of the amine-based curing agent is 400 to 1300.)
[2] The polishing pad according to [1], wherein the isocyanate-terminated urethane prepolymer is a reaction product of a polyol component and a polyisocyanate component.
[3] The polishing pad according to [2], wherein the polyisocyanate component contains tolylene diisocyanate.
[4] The polishing pad according to [2] or [3], wherein the polyol component contains polyoxytetramethylene glycol.
[5] The polishing pad according to any one of [1] to [4], wherein the curable resin composition further contains microhollow spheres.
[6] The method for manufacturing a polishing pad according to any one of [1] to [5].
The method comprising molding the polishing layer.
[7] 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 [5] is used.

The polishing pad of the present invention has a lower hardness than the conventional polishing pad and generates less organic residue, and as a result, it is possible to suppress the generation of defects such as scratches and organic residues.

(Action)
In the present invention, as the curing agent, an amine-based curing agent having a number average molecular weight of 400 to 1300 represented by the above formula (I) is used instead of the conventionally used MOCA.

Unexpectedly, by using an amine-based curing agent having a number average molecular weight of 400 to 1300 represented by the above formula (I), the present inventors have a lower hardness than the conventional polishing pad using MOCA. Further, it has been found that a polishing pad capable of suppressing the generation of defects such as scratches and organic residues can be obtained as a result of the generation of less organic residue. The details of the reason why these characteristics are obtained are not clear, but it is inferred as follows.

Since the amine-based curing agent has a polyoxytetramethylene chain which is a soft segment, the cured product using the amine-based curing agent has a lower hardness (rigidity) of the polishing pad than the cured product using MOCA. It is thought that it will be.

Further, the amine-based curing agent represented by the above formula (I) and having a number average molecular weight of 400 to 1300 has amino groups at both ends as in MOCA, and its reactivity with the isocyanate-terminated urethane prepolymer is MOCA. Since it is about the same level, it is considered that it is unlikely to remain as an unreacted substance in the cured resin composition.

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.

The polishing pad of the present invention has 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 is described above. It contains an amine-based curing agent represented by the formula (I) and having a number average molecular weight of 400 to 1300.

The polishing pad of the present invention has a polishing layer containing a polyurethane resin. The polishing layer is arranged in direct contact with the material to be polished, and the other part 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 it can suppress the generation of defects such as scratches and organic residues, and can 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 may be a plurality of layers 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 minute hollow spheres in the polyurethane resin. In this case, a curable resin composition containing an isocyanate-terminated urethane prepolymer, a curing agent, and a foaming agent can be prepared and molded by foaming and curing the curable resin composition.
The curable resin composition may be, for example, a two-component composition prepared by mixing a liquid A containing an isocyanate-terminated urethane prepolymer and a liquid 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.

The number average molecular weight of the amine-based curing agent represented by the formula (I), which is a curing agent contained in the curable resin composition, is 400 to 1300, preferably 425 to 1280, and most preferably 450 to 1250. When the molecular weight of the amine-based curing agent is within the above numerical range, a polishing pad capable of suppressing the generation of defects such as scratches and organic residues can be obtained. As the number average molecular weight of the amine-based curing agent in the present invention, a polystyrene-equivalent value measured by the GPC method can be used.

In the above formula (I), n is a natural number of 1 or more in which the number average molecular weight of the amine-based curing agent represented by the formula (I) is 400 to 1300, preferably 2 to 15 and more preferably 3 to 14. preferable.

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 capable of suppressing the generation of defects such as scratches and organic residues can be obtained.

The total amount of the curing agent is such that the ratio of the number of moles of NH ₂ of the curing agent (the number of moles of NH ₂ / the number of moles of NCO) to the number of moles of NCO of the isocyanate-terminated urethane prepolymer is 0.6 to 1.2. An amount of 0.7 to 1.0 is preferably used.

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 described below.
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. Further, trifunctional triamine compounds and tetrafunctional or higher functional polyamine compounds can also be used.

The curing agent may or may not contain the above-mentioned MOCA.
When the curing agent contains MOCA, its content in 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 capable of suppressing the generation of defects such as scratches and organic residues can be obtained.

The curing agent preferably does not contain a polyol-based curing agent. Here, "does not contain a polyol-based curing agent" means that it is not contained as an intentional additive, and even if it is contained as an impurity, it is 0.1% by mass or less with respect to the entire curing agent. It is preferably 0.05% by mass or less, more preferably 0.01% by mass or less, and most preferably 0.01% by mass or less. When the polyol-based curing agent is within the above numerical range, a polishing pad capable of suppressing the generation of defects such as scratches and organic residues can be obtained. Examples of such a polyol curing agent include compounds described later as a polyol component of an 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 500, more preferably 350 to 495, and most preferably 400 to 490. 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.

Examples of the polyol component other than the alkylene glycol having a molecular weight of 50 to 300 contained in the isocyanate-terminated urethane prepolymer include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, and 1,3-. Diols such as butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol; polyoxytetramethylene glycol (PTMG), polyethylene glycol, Polyether polyols such as polypropylene glycol; polyester polyols such as reactants of ethylene glycol and adipic acid and reactants of butylene glycol and adipic acid; polycarbonate polyols; polycaprolactone polyols and the like can be mentioned.
Among these, it is preferable to use polyoxytetramethylene 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.

Examples of the polyisocyanate component contained in the isocyanate-terminated urethane prepolymer include m-phenylenedi isocyanate, p-phenylenedi isocyanate, 2,6-toluene diisocyanate (2,6-TDI), and 2,4-toluene diisocyanate (2). , 4-TDI), Naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), 4,4'-methylene-bis (cyclohexylisocyanate) (hydrogenated MDI), 3,3'-dimethoxy -4,4'-biphenyldiisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, xylylene-1,4-diisocyanate, 4,4'-diphenylpropanediisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene -1,2-diisocyanate, butylene-1,2-diisocyanate, cyclohexylene-1,2-diisocyanate, cyclohexylene-1,4-diisocyanate, p-phenylenediisothiocianate, xylylene-1,4-diisocyanate, Examples thereof include ethylidine diisocyanate.
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.

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 micro hollow sphere is an unexpanded heat-expandable micro sphere made 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.

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. It is preferably 0.1 to 10% by weight, more preferably 0.5 to 8% by weight, and particularly preferably 1 to 5% by weight.
As the polyisocyanate component to be 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.

The hardness of the polishing layer of the present invention is represented by A hardness or D hardness. If it is A hardness, it is preferably 80 to 99, more preferably 90 to 95, and if it is D hardness, it is preferably 25 to 55, 30 ~ 40 is more preferable. When the hardness is at least the above lower limit, the sinking of the polishing layer is suppressed during the polishing process, and the work can be flattened to a higher degree. When the hardness is at least the above upper limit, the work can be flattened. The occurrence of scratches can be further suppressed.

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): Erasmer (registered trademark) 250P (manufactured by Kumiai Chemical Industry Co., Ltd.), an amine-based curing agent represented by the above formula (I) and having a number average molecular weight of 488. Amine-based curing agent (2) ) ... Erasmer (registered trademark) 650P (manufactured by Kumiai Chemical Industry Co., Ltd.), an amine-based curing agent having a number average molecular weight of 888 represented by the above formula (I) Amine-based curing agent (3) ... Erasmer (3) Registered trademark) 1000P (manufactured by Kumiai Chemical Industry Co., Ltd.), an amine-based curing agent having a number average molecular weight of 1238 represented by the above formula (I) MOCA ... 3,3'-dichloro-4,4'-diaminodiphenylmethane (Also known as: methylenebis-o-chloroaniline) (NH ₂ equivalent = 133.5)
Polyol-based curing agent: Polytetramethylene ether glycol with a number average molecular weight of 1000, microhollow spheres:
EXPANCEL 551DE40d42 (manufactured by Philite Japan)

(Example 1)
100 g of the prepolymer (1) was prepared as the A component, 48 g of the amine-based curing agent (1) as the curing agent was prepared as the B component, and 2 g of the micro hollow sphere (EXPANCEL 551DE40d42) was prepared as the C component. The ratio of the number of moles of NH ₂ of the amine-based curing agent of component B (the number of moles of NH ₂ / the number of moles of NCO) to the number of moles of NCO of the prepolymer of component A 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.
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 withdrawn 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)
88 g of the amine-based curing agent (2) was prepared in place of 48 g of the amine-based curing agent (1) of the B component of Example 1. The ratio of the number of moles of NH ₂ of the amine-based curing agent of component B (the number of moles of NH ₂ / the number of moles of NCO) to the number of moles of NCO of the prepolymer of component A is 0.9.
After that, a urethane sheet was prepared in the same manner as in Example 1 to obtain a polishing pad.

(Example 3)
Instead of 48 g of the amine-based curing agent (1) of the B component of Example 1, 123 g of the amine-based curing agent (3) was prepared. The ratio of the number of moles of NH ₂ of the amine-based curing agent of component B (the number of moles of NH ₂ / the number of moles of NCO) to the number of moles of NCO of the prepolymer of component A is 0.9.
After that, a urethane sheet was prepared in the same manner as in Example 1 to obtain a polishing pad.

(Comparative Example 1)
27 g of MOCA was prepared in place of 48 g of the amine-based curing agent (1) of the B component of Example 1. The ratio of the number of moles of NH ₂ of the amine-based curing agent of component B (the number of moles of NH ₂ / the number of moles of NCO) to the number of moles of NCO of the prepolymer of component A is 0.9.
After that, a urethane sheet was prepared in the same manner as in Example 1 to obtain a polishing pad.

(Comparative Example 2)
Instead of 48 g of the amine-based curing agent (1) of the B component of Example 1, 13 g of MOCA and 49 g of a polyol curing agent were prepared. The ratio of the total number of moles of NH ₂ of the amine-based curing agent of component B and the number of moles of OH of the polyol curing agent to the number of moles of NCO of the prepolymer of component A (number of moles of NH ₂ + number of moles of OH). / The number of 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.

(Comparative Example 3)
99 g of a polyol curing agent was prepared in place of 48 g of the amine-based curing agent (1) of the B component of Example 1. The ratio of the number of moles of OH of the polyol curing agent of component B (the number of moles of OH / the number of moles of NCO) to the number of moles of NCO of the prepolymer of component A is 0.9.
After that, a urethane sheet was prepared in the same manner as in Example 1 to obtain a polishing pad.

(Evaluation methods)
The following A hardness and D hardness were measured for each of the polishing pads of Examples 1 to 3 and Comparative Examples 1 to 3, and the defects were evaluated.

(A hardness)
The A hardness of the polishing pad was measured using a shore A durometer in accordance with Japanese Industrial Standards (JIS-K-7311). Here, the sample was obtained by stacking a plurality of urethane sheets as needed so that the total thickness was at least 4.5 mm or more.

(D hardness)
The D hardness of the polishing pad was measured using a D-type hardness tester in accordance with Japanese Industrial Standards (JIS-K-6253). Here, the sample was obtained by stacking a plurality of urethane sheets as needed so that the total thickness was at least 4.5 mm or more.

(Defect)
Defect evaluation is performed by polishing 25 substrates based on the following polishing test conditions, and for the 5th 21st to 25th substrates after polishing, a wafer surface inspection device (Surfscan SP2xpDLS manufactured by KLA Tencor). The number of scratches (scratches) caused by the hardness of the polishing pad and the number of organic residues adhering to the surface of the substrate were each evaluated. In the evaluation of defects, less than 200 defects (scratches or organic residues) of 0.16 μm or more on a 12-inch (300 mm <b) wafer were evaluated as ◯, and 200 or more were evaluated as x.

(Conditions for polishing test)
-Grinding machine used: F-REX300 manufactured by Ebara Corporation
・ Disc: 3MA188 (# 100)
-Rotation speed: (Surface plate) 70 rpm, (Top ring) 71 rpm
・ Polishing pressure: 3.5psi
-Abrasive: manufactured by Cabot Corporation, product number: SS25 (SS25 undiluted solution: pure = 1: 1 weight ratio mixed solution is used)
・ Abrasive temperature: 20 ° C
・ Abrasive discharge amount: 200 ml / min
Work (workpiece 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. The initial temperature for polishing is from 20 ° C to the pad surface temperature during polishing. Increases to 40-50 ° C.

The results are shown in Tables 1 and 2 below.

From the results of Tables 1 and 2, the polishing pads of Examples 1 to 3 using the amine-based curing agents (1) to (3) as the curing agent have lower hardness than the polishing pads using only MOCA as the curing agent. As a result, the number of scratches generated on the object to be polished has decreased.
On the other hand, the polishing pad of Comparative Example 1 using only MOCA as a curing agent generated many scratches.
Further, the polishing pad of Comparative Example 2 in which MOCA mixed with a polyol-based curing agent was used as the curing agent and the polishing pad of Comparative Example 3 in which only the polyol-based curing agent was used as the curing agent had low hardness and scratches were generated. However, many defects were observed due to the organic residue, which was considered to be caused by the unreacted component of the polyol-based curing agent. Further, in Comparative Example 3, the reaction curing time at the time of manufacturing the polishing pad was long, it was difficult to slice the obtained foam, and there was a problem in manufacturing.

From the above results, the polishing pad using an amine-based curing agent having a number average molecular weight of 400 to 1300 represented by the above formula (I) as a curing agent has a lower hardness than the conventional polishing pad, and is an organic residue. As a result, it was confirmed that the occurrence of defects such as scratches and organic residues can be suppressed.

Claims (4)

A polishing pad having a polishing layer containing a polyurethane resin.
The polyurethane resin is a cured product of a curable resin composition composed of an isocyanate-terminated urethane prepolymer , a curing agent , and microhollow spheres .
The isocyanate-terminated urethane prepolymer is a reaction product of a polyol component and a polyisocyanate component, and the polyisocyanate component is composed of tolylene diisocyanate.
The polishing pad contains an amine-based curing agent having a number average molecular weight of 400 to 1300 represented by the following formula (I).

(In the above formula (I), n is a natural number of 1 or more in which the number average molecular weight of the amine-based curing agent is 400 to 1300.) The polishing pad according to claim 1 , wherein the polyol component contains polyoxytetramethylene glycol. The method for manufacturing a polishing pad according to claim 1 or 2 .
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 claim 1 or 2 is used.