CN117120213A - Polishing pad and method for producing polished product - Google Patents

Polishing pad and method for producing polished product Download PDF

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Publication number
CN117120213A
CN117120213A CN202280024991.XA CN202280024991A CN117120213A CN 117120213 A CN117120213 A CN 117120213A CN 202280024991 A CN202280024991 A CN 202280024991A CN 117120213 A CN117120213 A CN 117120213A
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China
Prior art keywords
polishing
detection window
end point
point detection
polishing pad
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CN202280024991.XA
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Chinese (zh)
Inventor
立野哲平
系山光纪
关谷仁志
小池坚一
栗原浩
山口早月
高见泽大和
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Fujibo Holdins Inc
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Fujibo Holdins Inc
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Application filed by Fujibo Holdins Inc filed Critical Fujibo Holdins Inc
Priority claimed from PCT/JP2022/014016 external-priority patent/WO2022210264A1/en
Publication of CN117120213A publication Critical patent/CN117120213A/en
Pending legal-status Critical Current

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Abstract

A polishing pad comprising a polyurethane sheet as a polishing layer and an end point detection window provided in an opening of the polyurethane sheet, wherein the end point detection window has a storage modulus E 'at 90 ℃ in dynamic viscoelasticity measurement performed in a stretching mode under conditions of a frequency of 1.0Hz and 10-100℃' W90 Is 1.0X10 7 Pa or more, D hardness (D W80 ) At 20 ℃ D hardness (D W20 ) 40 to 90.

Description

Polishing pad and method for producing polished product
Technical Field
The present invention relates to a polishing pad and a method for producing a polished product using the same.
Background
In the semiconductor manufacturing process, chemical Mechanical Polishing (CMP) is used in planarization after the formation of an insulating film and in the formation of metal wiring. One of important technologies required for chemical mechanical polishing is polishing endpoint detection for detecting whether or not a polishing process is completed. For example, over-grinding or under-grinding relative to the targeted grinding endpoint directly results in poor product. Therefore, in chemical mechanical polishing, it is necessary to strictly control the polishing amount by polishing end point detection.
Chemical mechanical polishing is a complicated process, and changes in polishing rate (polishing rate) occur due to the influence of variations in the operating state of a polishing apparatus, the quality of consumables (slurry, polishing pad, dresser, etc.), and the state of polishing with time. In recent years, the accuracy and in-plane uniformity of the residual film thickness required in the semiconductor manufacturing process have become more and more stringent. In this case, it becomes more difficult to detect the polishing end point with sufficient accuracy.
As a main method of polishing end point detection, an optical end point detection method, a torque end point detection method, an eddy current end point detection method, and the like are known, in which a wafer is irradiated with light through a transparent window member provided on a polishing pad, and reflected light is monitored to perform end point detection.
As a polishing pad using such an optical endpoint detection method, for example, patent document 1 discloses a polishing pad having a pad body and a transparent window member integrally formed with a part of the pad body, in which the surface of the window member is recessed from the surface of the pad body, with the aim of providing a polishing pad capable of suppressing slurry from being retained in a groove of the window member and improving detection accuracy of a polishing rate.
Prior art literature
Patent literature
Patent document 1: JP 2002-001647A
Disclosure of Invention
Problems to be solved by the invention
However, as one of the methods for producing the polishing pad having the window, there is a method in which the resin composition is filled and cured in a state in which the window member is fixed to a mold, and then the obtained cured product is sliced and thereafter subjected to a finishing treatment. Here, since the window member and the cured product of the resin composition are formed of different materials, there are some differences in physical properties, but there is a possibility that the window portion will be dented or broken when dicing is performed, for example. In addition, when the dressing treatment is performed, the window may be recessed due to a difference in the abrasion amount between the window and the polishing layer.
If such dishing occurs, slurry and polishing dust are likely to accumulate therein, and scratches and the like may occur, which may reduce the surface quality of the workpiece. In addition, when the abrasion amount of the window portion is small, the window portion is more likely to remain than the polishing layer as polishing proceeds, and as a result, it is considered that the window portion becomes convex. Such a convex window portion may also cause scratches or the like, which may reduce the surface quality of the workpiece.
The present application has been made in view of the above problems, and one of the objects of embodiments 1 and 3 is to provide a polishing pad having excellent flatness in slicing and dressing processes, and a method for producing a polished product using the polishing pad.
Further, when the characteristics of the polishing layer and the end point detection window are different as in patent document 1, for example, the end point detection window is polished faster than the polishing layer and becomes recessed, and slurry and polishing dust are likely to accumulate therein, and defects (surface defects) may occur. Further, when the polishing of the polishing layer is slower than the portion of the end point detection window, the end point detection window becomes a convex portion as the polishing proceeds, and defects may occur, which may reduce the surface quality of the object to be polished.
The present application has been made in view of the above-described problems, and an object thereof is to provide a polishing pad and a method for producing a polished product using the same, which are less likely to cause defects and have excellent surface quality even when the polishing pad has an end point detection window, in embodiments 2 and 4.
Means for solving the problems
[ embodiment 1 ]
The inventors of the present application have conducted intensive studies in order to solve the above-mentioned problems. As a result, it has been found that the above problems can be solved by providing an end point detection window with a predetermined viscoelasticity and hardness, and the present application has been completed.
That is, embodiment 1 of the present invention is as follows.
〔1〕
A polishing pad having a polishing layer and an end point detection window provided in an opening of the polishing layer,
in the dynamic viscoelasticity measurement of the end point detection window performed in the stretching mode at a frequency of 1.0Hz and at a temperature of 10 to 100 ℃, the storage modulus E 'at 90℃' W90 Is 1.0X10 7 The pressure of the mixture is more than Pa,
d hardness (D W80 ) Is more than or equal to 40 percent,
d hardness (D W20 ) 40 to 90.
〔2〕
The polishing pad of [ 1 ], wherein the end point detection window comprises polyurethane resin WI.
〔3〕
The polishing pad according to [ 2 ], wherein the polyurethane resin WI contains a structural unit derived from an alicyclic isocyanate and/or an aliphatic isocyanate.
〔4〕
The polishing pad according to [ 2 ] or [ 3 ], wherein the polyurethane resin WI contains a structural unit derived from a compound having 3 or more hydroxyl groups.
〔5〕
The polishing pad according to any one of [ 1 ] to [ 4 ], wherein in the dynamic viscoelasticity measurement of the end point detection window, the storage modulus E' at 30 ℃. W30 60X 10 7 ～100×10 7 Pa。
〔6〕
The polishing pad according to any one of [ 1 ] to [ 5 ], wherein in the dynamic viscoelasticity measurement of the end point detection window, the peak temperature of tan δ is 70 to 100 ℃.
〔7〕
The polishing pad according to any one of [ 1 ] to [ 6 ], wherein the polishing layer comprises a polyurethane resin P and hollow fine particles dispersed in the polyurethane resin P.
〔8〕
A method for producing a polished product, comprising:
a polishing step of polishing an object to be polished with the polishing pad of any one of [ 1 ] to [ 7 ] in the presence of a polishing slurry to obtain a polished product; and
an end point detection step of performing end point detection by an optical end point detection method during the polishing.
[ embodiment 2 ]
The inventors of the present application have conducted intensive studies in order to solve the above-mentioned problems. As a result, the inventors have found that the above problems can be solved by making the end point detection window have a predetermined relationship with the viscoelasticity of the polishing layer, and completed the present application.
That is, embodiment 2 of the present application is as follows.
〔1〕
A polishing pad having a polishing layer and an end point detection window provided in an opening of the polishing layer,
in the stretching mode, frequency 1.0In the dynamic viscoelasticity measurement performed under the conditions of Hz and 10-100 ℃, the storage modulus E 'of the end point detection window at 30℃' W30 Storage modulus E 'at 30 ℃ with the polishing layer' P30 Ratio (E ')' P30 /E’ W30 ) 0.60 to 1.50.
〔2〕
The polishing pad of [ 1 ], wherein the end point detection window comprises polyurethane resin WI.
〔3〕
The polishing pad according to [ 2 ], wherein the polyurethane resin WI contains a structural unit derived from an alicyclic isocyanate and/or an aliphatic isocyanate.
〔4〕
The polishing pad according to [ 2 ] or [ 3 ], wherein the polyurethane resin WI contains a structural unit derived from a compound having 3 or more hydroxyl groups.
〔5〕
The polishing pad according to any one of [ 1 ] to [ 4 ], wherein in the dynamic viscoelasticity measurement, the storage modulus E' of the end point detection window at 50 ℃. W50 Storage modulus E 'at 50 ℃ with the polishing layer' P50 Ratio (E ')' P50 /E’ W50 ) 0.70 to 2.00.
〔6〕
The polishing pad according to any one of [ 1 ] to [ 5 ], wherein in the dynamic viscoelasticity measurement of the end point detection window, the storage modulus E' at 30 ℃. W30 Is 10 multiplied by 10 7 ～60×10 7 Pa。
〔7〕
The polishing pad according to any one of [ 1 ] to [ 6 ], wherein the end point detection window has a D hardness (D W20 ) 40 to 70.
〔8〕
The polishing pad according to any one of [ 1 ] to [ 7 ], wherein the polishing layer comprises a polyurethane resin P and hollow fine particles dispersed in the polyurethane resin P.
〔9〕
A method for producing a polished product, comprising:
a polishing step of polishing an object to be polished with the polishing pad according to any one of claims [ 1 ] to [ 8 ] in the presence of a polishing slurry; and
an end point detection step of performing end point detection by an optical end point detection method during the polishing.
[ embodiment 3 ]
The inventors of the present application have conducted intensive studies in order to solve the above-mentioned problems. As a result, it has been found that the above problems can be solved by providing a predetermined relationship between the endpoint detection window and the polishing layer in analysis by pulse NMR, and the present application has been completed.
That is, embodiment 3 of the present application is as follows.
〔1〕
A polishing pad having a polishing layer and an end point detection window provided in an opening of the polishing layer,
when the free induction decay curve of the spin-spin relaxation of 1H obtained by the Solid Echo method (Solid Echo method) measurement using pulse NMR is separated into 3 curves from 3 components of a crystalline phase, an intermediate phase and an amorphous phase in a sequential waveform of relaxation time from short to long,
the ratio of the presence ratio Lw20 of the amorphous phase of the end point detection window to the presence ratio Lp20 of the amorphous phase of the polishing layer (Lp 20/Lw 20) at 20 ℃ is 0.5 to 2.0,
The ratio (Sp 80/Sw 80) of the presence ratio Sw80 of the crystal phase of the end point detection window to the presence ratio Sp80 of the crystal phase of the polishing layer at 80 ℃ is 0.5 to 2.0.
〔2〕
The polishing pad according to [ 1 ], wherein the ratio of the presence ratio Mw20 of the intermediate phase of the end point detection window to the presence ratio MP20 of the intermediate phase of the polishing layer (MP 20/Mw 20) at 20 ℃ is 0.7 to 1.5.
〔3〕
The polishing pad according to [ 1 ] or [ 2 ], wherein the ratio of the presence of the intermediate phase of the end point detection window to the presence of the intermediate phase of the polishing layer (Mp 80/Mw 80) at 80 ℃ is 0.5 to 1.5.
〔4〕
The polishing pad according to any one of [ 1 ] to [ 3 ], wherein a difference (|Lp20-Lw20|) between the presence ratio Lw20 and the presence ratio Lp20 is 10 or less.
〔5〕
The polishing pad according to any one of [ 1 ] to [ 4 ], wherein a difference (|Sp80-Sw80|) between the presence ratio Sw80 and the presence ratio Sw80 is 15 or less.
〔6〕
The polishing pad according to any one of [ 1 ] to [ 5 ], wherein the end point detection window comprises polyurethane resin WI,
the polyurethane resin WI contains structural units derived from aliphatic isocyanates.
〔7〕
The polishing pad according to any one of [ 1 ] to [ 6 ], wherein the polishing layer comprises a polyurethane resin P,
The polyurethane resin P contains structural units derived from an aromatic isocyanate.
〔8〕
The polishing pad according to any one of [ 1 ] to [ 7 ], wherein the polishing layer contains hollow fine particles dispersed in the polishing layer.
〔9〕
A method for producing a polished product, comprising:
a polishing step of polishing an object to be polished with the polishing pad of any one of [ 1 ] to [ 8 ] in the presence of a polishing slurry to obtain a polished product; and
an end point detection step of performing end point detection by an optical end point detection method during the polishing.
[ embodiment 4 ]
The inventors of the present application have conducted intensive studies in order to solve the above-mentioned problems. As a result, the inventors have found that the above problems can be solved by making the end point detection window have a predetermined relationship with the viscoelasticity of the polishing layer, and completed the present application.
That is, embodiment 4 of the present application is as follows.
〔1〕
A polishing pad having a polishing layer and an end point detection window provided in an opening of the polishing layer,
in the dynamic viscoelasticity measurement under conditions of a stretching mode, a frequency of 1.6Hz, 30-55 ℃ and a water-immersed state, the ratio (E 'p40/E' w 40) of the storage modulus E 'w40 of the end point detection window at 40 ℃ to the storage modulus E' p40 of the polishing layer at 40 ℃ is 0.70-3.00.
〔2〕
The polishing pad according to [ 1 ], wherein a ratio (E 'p50/E' w 50) of a storage modulus E 'w50 of the end point detection window at 50 ℃ to a storage modulus E' p50 of the polishing layer at 50 ℃ in the dynamic viscoelasticity measurement is 0.70 to 5.00.
〔3〕
The polishing pad according to [ 1 ] or [ 2 ], wherein a difference (|tan δw30-tan δp30|) between a loss factor tan δw30 of the end point detection window at 30 ℃ and a loss factor tan δp30 of the polishing layer at 30 ℃ in the dynamic viscoelasticity measurement is 0.05 to 0.30.
〔4〕
The polishing pad according to any one of [ 1 ] to [ 3 ], wherein a difference (|tanδw40-tanδp 40) between a loss factor tanδw40 of the end point detection window at 40 ℃ and a loss factor tanδp40 of the polishing layer at 40 ℃ in the dynamic viscoelasticity measurement is 0.05 to 0.40.
〔5〕
The polishing pad according to any one of [ 1 ] to [ 4 ], wherein a difference (|tanδw50-tanδp50|) between a loss factor tan δw50 of the end point detection window at 50 ℃ and a loss factor tan δp50 of the polishing layer at 50 ℃ in the dynamic viscoelasticity measurement is 0.05 to 0.50.
〔6〕
The polishing pad according to any one of [ 1 ] to [ 5 ], wherein the end point detection window comprises polyurethane resin WI,
The polyurethane resin WI contains structural units derived from aliphatic isocyanates.
〔7〕
The polishing pad according to any one of [ 1 ] to [ 6 ], wherein the polishing layer comprises a polyurethane resin P,
the polyurethane resin P contains structural units derived from an aromatic isocyanate.
〔8〕
The polishing pad according to any one of [ 1 ] to [ 7 ], wherein the polishing layer contains hollow fine particles dispersed in the polishing layer.
〔9〕
A method for producing a polished product, comprising:
a polishing step of polishing an object to be polished with the polishing pad of any one of [ 1 ] to [ 8 ] in the presence of a polishing slurry to obtain a polished product; and
an end point detection step of performing end point detection by an optical end point detection method during the polishing.
Effects of the invention
According to embodiment 1 and embodiment 3 of the present invention, a polishing pad excellent in flatness during slicing and dressing and a method for producing a polished product using the polishing pad can be provided.
Further, according to embodiment 2 and embodiment 4 of the present invention, a polishing pad and a method for producing a polished article using the same, which are less likely to cause defects and have excellent surface quality, can be provided even when the end point detection window is provided.
Drawings
FIG. 1 is a schematic perspective view of polishing pads according to embodiment 1 to embodiment 4.
FIG. 2 is a schematic cross-sectional view of the end point detection window portion of the polishing pad according to embodiment 1 to embodiment 4.
Fig. 3 is a schematic cross-sectional view of another embodiment of the end point detection window portion of the polishing pad according to embodiment 1 to embodiment 4.
Fig. 4 is a schematic diagram showing a film thickness control system mounted on CMP.
Fig. 5A is a view showing the surface state of the end point detection window portion of the polishing pad of example A1 before trimming after dicing.
Fig. 5B is a view showing the surface state of the end point detection window portion of the polishing pad of comparative example A1 before trimming after dicing.
Fig. 5C is a view showing the surface state of the end point detection window portion of the polishing pad of comparative example A2 before trimming after dicing.
Fig. 5D is a view showing the surface state of the end point detection window portion of the polishing pad of example A2 before trimming after dicing.
Fig. 6A is a diagram showing a surface state of an end point detection window portion of the polishing pad of example A1 after dressing.
Fig. 6B is a view showing the surface state of the end point detection window portion of the polishing pad of comparative example A1 after dressing.
Fig. 6C is a view showing the surface state of the end point detection window portion of the polishing pad of comparative example A2 after dressing.
Fig. 6D is a diagram showing the surface state of the end point detection window portion of the polishing pad of example A2 after dressing.
Fig. 7A is a view showing the surface state of the end point detection window portion of the polishing pad of example C1 before trimming after dicing.
Fig. 7B is a view showing the surface state of the end point detection window portion of the polishing pad of example C2 before trimming after dicing.
Fig. 7C is a view showing the surface state of the end point detection window portion of the polishing pad of comparative example C1 before trimming after dicing.
Fig. 8A is a diagram showing the surface state of the end point detection window portion of the polishing pad of example C1 after dressing.
Fig. 8B is a diagram showing the surface state of the end point detection window portion of the polishing pad of example C2 after dressing.
Fig. 8C is a view showing the surface state of the end point detection window portion of the polishing pad of comparative example C1 after dressing.
Detailed Description
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, if necessary, but the present invention is not limited thereto, and various modifications may be made without departing from the scope of the present invention. In the drawings, the same elements are denoted by the same reference numerals, and redundant description thereof is omitted. The positional relationship between the upper, lower, left, right, etc. is based on the positional relationship shown in the drawings unless otherwise specified. The dimensional ratios in the drawings are not limited to the ratios shown in the drawings.
1. Embodiment 1
1.1. Polishing pad
The polishing pad of embodiment 1 has a polishing layer and an end point detection window provided in an opening of the polishing layer, and has a storage modulus E 'at 90℃in dynamic viscoelasticity measurement of the end point detection window in a stretching mode at a frequency of 1.0Hz and at a temperature of 10 to 100℃' W90 Is 1.0X10 7 At 80 ℃ of the end point detection window, D hardness (D W80 ) At 20 ℃ for the end point detection window, D hardness (D W20 ) 40 to 70.
In this way, the flatness can be improved from the viewpoint that the protruding portion is less likely to be generated during the dicing process, and from the viewpoint that the polishing layer is less likely to be excessively polished than the end point detection window during the trimming process, the flatness can be improved. In embodiment 1, these 2 types of flatness are collectively referred to simply as "flatness".
Fig. 1 is a schematic perspective view of a polishing pad according to embodiment 1. As shown in fig. 1, the polishing pad 10 of embodiment 1 includes a polishing layer 11 and an end point detection window 12, and may include a buffer layer 13 on the side opposite to the polishing surface 11a, if necessary.
Fig. 2 to 3 show cross-sectional views of the periphery of the end point detection window 12 in fig. 1. As shown in fig. 2 to 3, an adhesive layer 14 may be provided between the polishing layer 11 and the buffer layer 13, and an adhesive layer 15 for bonding to the table 22 of fig. 4 may be provided on the surface of the buffer layer 13. The polishing surface 11a of the polishing pad of embodiment 1 may be uneven as shown in fig. 3, in which grooves 16 are formed, in addition to being flat as shown in fig. 2. The grooves 16 may be formed singly or in combination to form a plurality of grooves having various shapes such as concentric circles, lattices, and radial shapes.
1.1.1. Endpoint detection window
The end point detection window is a transparent member provided in the opening of the polishing layer, and serves as a light transmission path from the film thickness detection sensor in optical end point detection. In embodiment 1, the end point detection window is circular, but may be square, rectangular, polygonal, elliptical, or the like as necessary.
In embodiment 1, in the process of manufacturing the polishing pad, when dicing is performed, the end point detection window is suppressed from being recessed from the polishing layer and from being broken, and the end point detection window is suppressed from being recessed from the polishing layer and from being protruded from the polishing layer during the dressing process, and the flatness is improved, and from this point of view, the storage modulus E' and D hardness of the end point detection window are defined.
1.1.1.1. Dynamic viscoelasticity
The storage modulus E' of the end point detection window in embodiment 1 can be obtained by dynamic viscoelasticity measurement performed under conditions of a stretching mode, a frequency of 1.0Hz, and a temperature of 10 to 100 ℃. Since the object is sliced while being heated as described later, the storage modulus E 'of the end point detection window in embodiment 1 is defined as the storage modulus E' at 90 ℃. W90 . In embodiment 1, the peak temperature position of the loss tangent tan δ may be further adjusted so that the loss modulus E "(viscous component) is superior to the storage modulus E ' (elastic component) at the time of slicing, and the storage modulus E ' at 30 ℃ may be defined from the viewpoint of showing the characteristics of the end point detection window at the time of trimming ' W30 。
Storage modulus E 'at 90℃of the endpoint detection window' W90 Is 1.0X10 7 Pa or more, preferably 1.25X10 7 ～20×10 7 Pa, more preferably 1.5X10 7 ～10×10 7 Pa. By letting the storage modulus E' W90 Is 1.0X10 7 Pa or more, the end point detection window can be suppressed from being recessed from the polishing layer, protruding from the polishing layer, or being capable of being cutCracking can be suppressed, and flatness can be further improved.
In the dynamic viscoelasticity measurement of the end point detection window, the peak temperature of tan δ is preferably 70 to 100 ℃, more preferably 70 to 95, and even more preferably 75 to 90. When the peak temperature of tan δ is within the above range, the end point detection window can be suppressed from being recessed or protruding from the polishing layer during slicing, and cracking can be suppressed, thereby further improving flatness.
Further, storage modulus E 'at 30℃' W30 Preferably 10X 10 7 ～80×10 7 Pa, more preferably 20X 10 7 ～70×10 7 Pa, more preferably 30X 10 7 ～70×10 7 Pa. By letting the storage modulus E' W30 In the above range, the end point detection window can be suppressed from being recessed from the polishing layer during the dressing process, and the flatness can be further improved.
The measurement conditions for the dynamic viscoelasticity measurement are not particularly limited, and the measurement can be performed under the conditions described in examples.
1.1.1.2.D hardness
D hardness at 80℃of the endpoint detection Window (D W80 ) The content is 40 or more, preferably 40 to 60, more preferably 40 to 50. By making D hardness (D W80 ) When the number of the polishing layer is 40 or more, the end point detection window can be suppressed from being recessed or protruding from the polishing layer, cracking can be suppressed, and flatness can be further improved.
In addition, D hardness (D W20 ) From 40 to 90, preferably from 50 to 85, more preferably from 55 to 80. By making D hardness (D W20 ) In the above range, the end point detection window can be suppressed from being recessed or protruding from the polishing layer during the dressing process, and the flatness can be further improved.
The conditions for measuring D hardness are not particularly limited, and measurement can be performed by the conditions described in examples.
1.1.1.3. Constituent material
The material constituting the end point detection window is not particularly limited as long as it is a transparent member capable of functioning as a window, and examples thereof include polyurethane resin WI, polyvinyl chloride resin, polyvinylidene fluoride resin, polyethersulfone resin, polystyrene resin, polyethylene resin, polytetrafluoroethylene resin, and the like. Among them, polyurethane resin WI is preferable. By using such a resin, the dynamic viscoelasticity, D hardness, and transparency can be more easily adjusted, and the flatness can be further improved.
The polyurethane resin WI may be synthesized from a polyisocyanate and a polyol, and contains a structural unit derived from the polyisocyanate and a structural unit derived from the polyol.
1.1.1.3.1. Structural units derived from polyisocyanates
The structural unit derived from the polyisocyanate is not particularly limited, and examples thereof include a structural unit derived from an alicyclic isocyanate, a structural unit derived from an aliphatic isocyanate, and a structural unit derived from an aromatic isocyanate. Among them, the polyurethane resin WI preferably contains structural units derived from an alicyclic isocyanate and/or an aliphatic isocyanate. Thus, the dynamic viscoelasticity characteristics, D hardness (D W20 ) And D hardness (D W80 ) In addition to further improving the transparency, the yellowing resistance of the window tends to be further improved when the content is within the above range. Further, flatness can be further improved.
The alicyclic isocyanate is not particularly limited, and examples thereof include 4,4' -methylene-bis (cyclohexyl isocyanate) (hydrogenated MDI), cyclohexylene-1, 2-diisocyanate, cyclohexylene-1, 4-diisocyanate, isophorone diisocyanate, and the like.
The aliphatic isocyanate is not particularly limited, and examples thereof include Hexamethylene Diisocyanate (HDI), pentamethylene Diisocyanate (PDI), tetramethylene diisocyanate, propylene-1, 2-diisocyanate, butylene-1, 2-diisocyanate, trimethylene diisocyanate, and trimethylhexamethylene diisocyanate.
The aromatic isocyanate is not particularly limited, and examples thereof include benzene diisocyanate, 2, 6-toluene diisocyanate (2, 6-TDI), 2, 4-toluene diisocyanate (2, 4-TDI), xylene diisocyanate, naphthalene diisocyanate, and diphenylmethane-4, 4' -diisocyanate (MDI).
1.1.1.3.2. Structural units derived from polyols
The structural unit derived from a polyol is not particularly limited, and examples thereof include a low molecular polyol having a molecular weight of less than 300 and a high molecular polyol having a molecular weight of 300 or more.
The low molecular weight polyol is not particularly limited, and examples thereof include low molecular weight polyols having 2 hydroxyl groups such as ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1, 2-butanediol, 1, 3-butanediol, 2, 3-butanediol, 1, 4-butanediol, 1, 5-pentanediol, neopentyl glycol, 1, 6-hexanediol, 2, 5-hexanediol, dipropylene glycol, 2, 4-trimethyl-1, 3-pentanediol, tricyclodecanedimethanol, 1, 4-cyclohexanedimethanol and the like; low molecular polyols having 3 or more hydroxyl groups such as glycerin, hexanetriol, trimethylolpropane, isocyanuric acid and erythritol. The low molecular weight polyol may be used alone or in combination of at least 2.
Among them, a low molecular polyol having 3 or more hydroxyl groups is preferable, and glycerin is more preferable. By using such a low-molecular polyol, dynamic viscoelasticity and D hardness can be easily adjusted within the above-mentioned ranges, and the abrasion loss can be adjusted, so that the flatness can be further improved, and the transparency can be further improved, and the yellowing resistance of the window can be further improved.
The content of the structural unit derived from the low-molecular polyol having 3 or more hydroxyl groups is preferably 8.0 to 30 parts, more preferably 10 to 25 parts, and still more preferably 12.5 to 20 parts relative to 100 parts of the structural unit derived from the polyisocyanate. By setting the content of the structural unit derived from the low-molecular polyol having 3 or more hydroxyl groups within the above range, the dynamic viscoelasticity and D hardness can be easily adjusted to the above ranges, and the flatness can be further improved, and the yellowing resistance of the window tends to be further improved in addition to the transparency.
The polymer polyol is not particularly limited, and examples thereof include polyether polyols, polyester polyols, polycarbonate polyols, polyether polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols and vinyl monomer modified polyols. The polymer polyol may be used alone or in combination of at least 2 kinds.
The number average molecular weight of the polymer polyol is preferably 300 to 1200, more preferably 400 to 950, and still more preferably 500 to 800. By using such a polymer polyol, dynamic viscoelasticity and D hardness tend to be easily adjusted to the above-described ranges.
Among them, polyether polyols are preferable, and polytetramethylene ether glycol is more preferable. By using such a polymer polyol, the dynamic viscoelasticity and D hardness can be easily adjusted within the above-described ranges, and the hardness at low temperatures can be easily adjusted, so that the decrease in hardness with an increase in temperature can be suppressed. In addition, the flatness can be further improved, and the transparency can be further improved, and the yellowing resistance of the window tends to be further improved.
The content of the structural unit derived from the polyether polyol is preferably 40 to 100 parts, more preferably 50 to 90 parts, still more preferably 60 to 84 parts, relative to 100 parts of the structural unit derived from the polyisocyanate. By setting the content of the structural unit derived from the polyether polyol to the above range, the dynamic viscoelasticity and D hardness can be easily adjusted to the above range, and the flatness can be further improved, and the yellowing resistance of the window tends to be further improved in addition to the transparency.
Further, as the polyol, a low molecular polyol and a high molecular polyol are preferably used in combination, and a low molecular polyol having 3 or more hydroxyl groups and a polyether polyol are more preferably used in combination. Accordingly, the dynamic viscoelasticity and D hardness can be easily adjusted within the above ranges, and the hardness at low temperatures can be easily adjusted, so that the decrease in hardness with an increase in temperature can be suppressed. In addition, the flatness can be further improved, and the transparency can be further improved, and the yellowing resistance of the window tends to be further improved.
From the above viewpoints, the content of the polyether polyol is preferably 1.0 to 9.0 parts, more preferably 2.0 to 8.0 parts, and even more preferably 3.0 to 7.0 parts, relative to 1 part of the low-molecular polyol having 3 or more hydroxyl groups.
1.1.2. Polishing layer
The polishing layer of embodiment 1 has an opening in which the end point detection window is buried. The position of the opening is not particularly limited, but is preferably set at a position in the radial direction corresponding to the film thickness detection sensor 23 provided on the stage 22. The number of openings is not particularly limited, but preferably has a plurality of openings at the same radial position so that the window passes through the film thickness detection sensor 23 a plurality of times when the polishing pad 10 attached to the table 22 is rotated once.
The polishing layer is not particularly limited, and examples thereof include a resin foam molded body, a non-foam molded body, a resin impregnated base material in which a fiber base material is impregnated with a resin, and the like.
The resin foam molded article herein refers to a foam made of a predetermined resin without a fibrous base material. The foaming shape is not particularly limited, and examples thereof include spherical cells, substantially spherical cells, tear-drop cells, and continuous cells in which the cells are partially connected.
The resin foam-free molded article is a foam-free molded article made of a predetermined resin without a fibrous base material. The foam-free material means a material having no bubbles as described above. In embodiment 1, a substance obtained by adhering and curing a curable composition to a substrate such as a film is also included in a non-foamed molded article of a resin. More specifically, a resin cured product formed by a gravure coating method, a small-diameter gravure coating method, a reverse roll coating method, a transfer roll coating method, a kiss coating method, a die coating method, a screen printing method, a spray coating method, or the like is also included in the foam-free molded body of the resin.
The resin-impregnated substrate means a substrate obtained by impregnating a fibrous substrate with a resin. The fibrous base material is not particularly limited, and examples thereof include woven fabrics, nonwoven fabrics, and knitted fabrics.
1.1.2.1. Dynamic viscoelasticity
The polishing layer preferably has a predetermined dynamic viscoelasticity property from the viewpoint of suppressing the end point detection window from being recessed from the polishing layer and cracking in the polishing pad obtained by slicing and dressing, in addition to the polishing rate and the surface quality of the object to be polished.
Specifically, in the dynamic viscoelasticity measurement performed under the conditions of a stretching mode, a frequency of 1.0Hz, and 10 to 100 ℃, the storage modulus E 'of the polishing layer at 90℃' P90 Preferably 1.0X10 7 Pa or more, preferably 2.0X10 7 ～20×10 7 Pa, more preferably 3.0X10 7 Pa～15×10 7 Pa. By letting the storage modulus E' P90 Is 1.0X10 7 Pa or more, in addition to the polishing rate and the surface quality of the workpiece, in the polishing pad obtained by slicing and dressing, the end point detection window is more suppressed from being in a state of being recessed, protruding, or broken from the polishing layer, and the flatness tends to be further improved.
In addition, from the same point of view, the storage modulus E' W90 With storage modulus E' P90 Difference (E' P90 -E’ W90 ) 9.5X10 7 Pa or less, preferably 1.0X10 7 Pa～9.0×10 7 Pa, more preferably 2.0X10 7 Pa～9.0×10 7 Pa. By making the difference (E' P90 -E’ W90 ) 9.5X10 7 Pa or less, the difference in physical properties between the polishing layer and the end point detection window becomes small under the dicing conditions, so that the polishing layer and the end point detection window are uniformly diced, and the window shape tends to be flat. Therefore, in the polishing pad obtained by slicing and dressing, the end point detection window is more depressed, protruded, or broken than the polishing layer, and the flatness tends to be further improved.
1.1.2.2. Polyurethane sheet
Hereinafter, a polyurethane sheet is exemplified as an example of the polishing layer. The polishing layer is not limited to a polyurethane sheet, and any resin sheet may be used.
The polyurethane resin P constituting the polyurethane sheet is not particularly limited, and examples thereof include polyester polyurethane resins, polyether polyurethane resins, and polycarbonate polyurethane resins. They may be used singly or in combination of 1 or more than 2.
As such polyurethane resin P, a reaction product of a urethane prepolymer and a curing agent is particularly preferable, and can be synthesized from a polyisocyanate and a polyol. The urethane prepolymers can be synthesized here from polyisocyanates and polyols. Hereinafter, the polyisocyanate, polyol and curing agent constituting the polyurethane resin P will be described.
1.1.2.2.1. Structural units derived from polyisocyanates
The structural unit derived from the polyisocyanate is not particularly limited, and examples thereof include a structural unit derived from an alicyclic isocyanate, a structural unit derived from an aliphatic isocyanate, and a structural unit derived from an aromatic isocyanate. Among them, aromatic isocyanates are preferable, and 2, 4-toluene diisocyanate (2, 4-TDI) is more preferable.
Examples of the alicyclic isocyanate, aliphatic isocyanate and aromatic isocyanate include the same materials as those exemplified in the above-mentioned end point detection window.
1.1.2.2.2. Structural units derived from polyols
The structural unit derived from a polyol is not particularly limited, and examples thereof include a low molecular polyol having a molecular weight of less than 300 and a high molecular polyol having a molecular weight of 300 or more. Among them, at least a low molecular polyol is preferably used, and a low molecular polyol and a high molecular polyol are preferably used in combination.
Examples of the low-molecular polyol and the high-molecular polyol include the same substances as those exemplified in the above-mentioned end point detection window. Among them, the low molecular polyol is preferably a low molecular polyol having 2 hydroxyl groups, and more preferably diethylene glycol. Further, as the polymer polyol, polyether polyol is preferable, and polytetramethylene ether glycol is more preferable.
1.1.2.2.3. Curing agent
The curing agent is not particularly limited, and examples thereof include polyamines and polyols. The curing agent may be used alone or in combination of at least 2 kinds.
The polyamine is not particularly limited, and examples thereof include aliphatic polyamines such as ethylenediamine, propylenediamine and hexamethylenediamine; alicyclic polyamines such as isophorone diamine and dicyclohexylmethane-4, 4' -diamine; aromatic polyamines such as 3,3 '-dichloro-4, 4' -diaminodiphenylmethane (MOCA), 4-methyl-2, 6-bis (methylthio) -1, 3-phenylenediamine, 2-methyl-4, 6-bis (methylthio) -1, 3-phenylenediamine, and 2, 2-bis (3-amino-4-hydroxyphenyl) propane.
Among them, aromatic polyamines are preferable, and 3 '-dichloro-4, 4' -diaminodiphenylmethane (MOCA) is more preferable.
As the polyol, the same polyols as those exemplified in the above-mentioned end point detection window can be exemplified. Among them, polymer polyols are preferable, polyether polyols are more preferable, and polypropylene glycol is further preferable.
1.1.2.2.4. Hollow microparticles
The polyurethane sheet is preferably a foamed polyurethane sheet containing a polyurethane resin P and hollow fine particles dispersed in the polyurethane resin P. Such polyurethane sheets have independent bubbles derived from hollow fine particles, and tend to easily adjust the dynamic viscoelastic properties and D hardness to the above-described ranges.
The hollow fine particles may be commercially available hollow fine particles, or hollow fine particles synthesized by a conventional method may be used. The material of the shell of the hollow fine particles is not particularly limited, and examples thereof include polyvinyl alcohol, polyvinylpyrrolidone, poly (meth) acrylic acid, polyacrylamide, polyethylene glycol, polyhydroxy ether acrylate, maleic acid copolymer, polyethylene oxide, polyurethane, acrylonitrile-vinylidene chloride copolymer, acrylonitrile-methyl methacrylate copolymer, vinyl chloride-ethylene copolymer, and the like.
The shape of the hollow fine particles is not particularly limited, and may be, for example, spherical or substantially spherical. When the hollow fine particles are inflatable balloons, the hollow fine particles may be used in an unexpanded state or in an inflated state.
The average particle diameter of the hollow fine particles contained in the polyurethane sheet is preferably 5 to 200. Mu.m, more preferably 5 to 80. Mu.m, still more preferably 5 to 50. Mu.m, particularly preferably 5 to 35. Mu.m. When the average particle diameter is within the above range, the dynamic viscoelasticity and D hardness tend to be easily adjusted to the above range. The average particle diameter can be measured by a laser diffraction particle size distribution measuring apparatus (for example, mastersizer-2000, manufactured by spectra).
1.1.3. Others
The polishing pad of embodiment 1 may have a buffer layer on the side of the polishing layer opposite to the polishing surface, or may have an adhesive layer between the polishing layer and the buffer layer on the surface of the buffer layer on the non-polishing layer side (the surface bonded to the polishing machine). In this case, the buffer layer and the adhesive layer have openings at the same positions as the positions of the polishing layer where the end point detection windows are located.
2. Embodiment 2
2.1. Polishing pad
The polishing pad of embodiment 2 comprises a polishing layer and an end point detection window provided in an opening of the polishing layer, wherein the end point detection window has a storage modulus E 'at 30℃in dynamic viscoelasticity measurement performed in a stretching mode at a frequency of 1.0Hz and at a temperature of 10 to 100℃' W30 Storage modulus E 'at 30 ℃ with the polishing layer' P30 Ratio (E ')' P30 /E’ W30 ) 0.60 to 1.50.
Thus, since the dynamic viscoelasticity characteristics of the polishing layer and the endpoint detection window become closer to each other during polishing, even when the endpoint detection window, which is a heterogeneous member, is embedded in the polishing layer, occurrence of defects (surface defects) on the surface of the object to be polished can be further suppressed. Therefore, an object to be polished having excellent surface quality can be obtained.
Fig. 1 is a schematic perspective view of a polishing pad according to embodiment 2. As shown in fig. 1, the polishing pad 10 of embodiment 2 includes a polishing layer 11 and an end point detection window 12, and may include a buffer layer 13 on the side opposite to the polishing surface 11a, if necessary.
Fig. 2 to 3 show cross-sectional views of the periphery of the end point detection window 12 in fig. 1. As shown in fig. 2 to 3, an adhesive layer 14 may be provided between the polishing layer 11 and the buffer layer 13, and an adhesive layer 15 for bonding to the table 22 of fig. 4 may be provided on the surface of the buffer layer 13. The polishing surface 11a of the polishing pad of embodiment 2 may be uneven as shown in fig. 3, in which grooves 16 are formed, in addition to being flat as shown in fig. 2. The grooves 16 may be formed singly or in combination to form a plurality of grooves having various shapes such as concentric circles, lattices, and radial shapes.
2.1.1. Endpoint detection window
The end point detection window is a transparent member provided in the opening of the polishing layer, and serves as a light transmission path from the film thickness detection sensor in optical end point detection. In embodiment 2, the end point detection window is circular, but may be square, rectangular, polygonal, elliptical, or the like as necessary.
In embodiment 2, the ratio of the storage modulus E' of the end point detection window to the polishing layer is defined in terms of suppressing occurrence of defects (surface defects) in the non-polished material due to excessive polishing of one of the end point detection window and the polishing layer by adjusting the degree of wear or the like of the end point detection window and the polishing layer during polishing.
2.1.1.1. Dynamic viscoelasticity
The storage modulus E' of the polishing layer and the end point detection window in embodiment 2 can be obtained by measuring dynamic viscoelasticity under conditions of a stretching mode and a frequency of 1.0Hz at 10 to 100 ℃. In embodiment 2, the ratio of the storage modulus E' at 30 ℃ is defined from the viewpoint of showing the characteristics of the polishing layer and the end point detection window at the time of polishing.
Storage modulus E 'at 30℃for endpoint detection window' W30 Storage modulus E 'at 30 ℃ with the polishing layer' P30 Ratio (E ')' P30 /E’ W30 ) From 0.60 to 1.50, preferably from 0.60 to 1.35, more preferably from 0.60 to 1.20. By letting the ratio (E' P30 /E’ W30 ) In the above range, the characteristics of the polishing layer and the endpoint detection window during polishing are similar, and thus the surface quality of the resulting polished object is further improved.
In addition, from the same point of view, in dynamic viscoelasticity measurementIn the end point detection window, storage modulus E 'at 50℃' W50 Storage modulus E 'at 50 ℃ with the polishing layer' P50 Ratio (E ')' P50 /E’ W50 ) Preferably 0.70 to 2.00, more preferably 0.70 to 1.85, and still more preferably 0.70 to 1.70. By letting the ratio (E' P50 /E’ W50 ) In the above range, the characteristics of the polishing layer and the endpoint detection window at the time of polishing are similar, and thus the surface quality of the resulting polished object tends to be further improved.
In the dynamic viscoelasticity measurement of the end point detection window, the storage modulus E 'at 30℃' W30 Preferably 10X 10 7 ～60×10 7 Pa, more preferably 15X 10 7 ～55×10 7 Pa, more preferably 20X 10 7 ～50×10 7 Pa. By letting the storage modulus E' W30 Within the above range, the surface quality of the resulting polished object tends to be further improved.
The measurement conditions for the dynamic viscoelasticity measurement are not particularly limited, and the measurement can be performed under the conditions described in examples.
2.1.1.2.D hardness
D hardness at 20℃of the end point detection window (D W20 ) From 40 to 70, preferably from 45 to 70, more preferably from 50 to 65. By making D hardness (D W20 ) Within the above range, the occurrence of defects (surface defects) tends to be further suppressed.
The conditions for measuring D hardness are not particularly limited, and can be measured by the conditions described in examples.
2.1.1.3. Constituent material
The material constituting the end point detection window is not particularly limited as long as it is a transparent member capable of functioning as a window, and examples thereof include polyurethane resin WI, polyvinyl chloride resin, polyvinylidene fluoride resin, polyethersulfone resin, polystyrene resin, polyethylene resin, polytetrafluoroethylene resin, and the like. Among them, polyurethane resin WI is preferable. By using such a resin, the dynamic viscoelasticity, D hardness, and transparency can be more easily adjusted.
The polyurethane resin WI may be synthesized from a polyisocyanate and a polyol, and contains a structural unit derived from the polyisocyanate and a structural unit derived from the polyol.
2.1.1.3.1. Structural units derived from polyisocyanates
The structural unit derived from the polyisocyanate is not particularly limited, and examples thereof include a structural unit derived from an alicyclic isocyanate, a structural unit derived from an aliphatic isocyanate, and a structural unit derived from an aromatic isocyanate. Among them, the polyurethane resin WI preferably contains structural units derived from an alicyclic isocyanate and/or an aliphatic isocyanate. Accordingly, the dynamic viscoelasticity and D hardness can be easily adjusted to the above ranges, and the transparency is further improved, and the yellowing resistance of the window is also further improved.
The alicyclic isocyanate, aliphatic isocyanate, and aromatic isocyanate are not particularly limited, and examples thereof include the compounds exemplified in embodiment 1.
2.1.1.3.2. Structural units derived from polyols
The structural unit derived from a polyol is not particularly limited, and examples thereof include a low molecular polyol having a molecular weight of less than 300 and a high molecular polyol having a molecular weight of 300 or more.
The low-molecular polyol is not particularly limited, and examples thereof include the compounds exemplified in embodiment 1.
Among them, a low molecular polyol having 3 or more hydroxyl groups is preferable, and glycerin is more preferable. By using such a low-molecular polyol, dynamic viscoelasticity and D hardness can be easily adjusted within the above-mentioned ranges, and the abrasion loss can be adjusted, and the transparency is further improved, and the yellowing resistance of the window tends to be further improved.
The content of the structural unit derived from the low-molecular polyol having 3 or more hydroxyl groups is preferably 7.5 to 30 parts, more preferably 10 to 25 parts, and still more preferably 12.5 to 20 parts relative to 100 parts of the structural unit derived from the polyisocyanate. By setting the content of the structural unit derived from the low-molecular polyol having 3 or more hydroxyl groups within the above range, it is easy to adjust the dynamic viscoelasticity and D hardness to the above range, and the yellowing resistance of the window tends to be further improved in addition to further improvement in transparency.
The polymer polyol is not particularly limited, and examples thereof include the compounds exemplified in embodiment 1.
The number average molecular weight of the polymer polyol is preferably 300 to 3000, more preferably 500 to 2500, and even more preferably 850 to 2000. By using such a polymer polyol, dynamic viscoelasticity and D hardness tend to be easily adjusted to the above-described ranges.
Among them, polyether polyols are preferable, and poly (oxytetramethylene) glycol is more preferable. By using such a polymer polyol, the dynamic viscoelasticity and D hardness can be easily adjusted within the above-described ranges, and the hardness at low temperatures can be easily adjusted, so that the decrease in hardness with an increase in temperature can be suppressed. In addition, there is a tendency that the yellowing resistance of the window is further improved in addition to the transparency.
The content of the structural unit derived from the polyether polyol is preferably 80 to 200 parts, more preferably 85 to 160 parts, and even more preferably 90 to 140 parts per 100 parts of the structural unit derived from the polyisocyanate. By setting the content of the structural unit derived from the polyether polyol to the above range, the dynamic viscoelasticity and D hardness can be easily adjusted to the above ranges, and the transparency and yellowing resistance of the window tend to be further improved.
Further, as the polyol, a low molecular polyol and a high molecular polyol are preferably used in combination, and a low molecular polyol having 3 or more hydroxyl groups and a polyether polyol are more preferably used in combination. Accordingly, the dynamic viscoelasticity and D hardness can be easily adjusted to the above ranges, and the transparency is further improved, and the yellowing resistance of the window is also further improved.
From the above viewpoints, the content of the polyether polyol is preferably 2.0 to 15.0 parts, more preferably 3.0 to 12.5 parts, and even more preferably 4.0 to 9.0 parts, relative to 1 part of the low-molecular polyol having 3 or more hydroxyl groups.
2.1.2. Polishing layer
The polishing layer of embodiment 2 has an opening in which the end point detection window is buried. The position of the opening is not particularly limited, but is preferably set at a position in the radial direction corresponding to the film thickness detection sensor 23 provided on the stage 22. The number of openings is not particularly limited, but a plurality of openings are preferably provided at the same radial position so that the window passes through the film thickness detection sensor 23 a plurality of times when the polishing pad 10 attached to the table 22 rotates once.
The polishing layer is not particularly limited, and examples thereof include a resin foam molded body, a non-foam molded body, a resin impregnated base material in which a fiber base material is impregnated with a resin, and the like.
Here, the resin foam, the non-foam, the resin impregnated base material, and the fiber base material are described in embodiment 1, and thus description thereof is omitted.
2.1.2.1. Dynamic viscoelasticity
In the dynamic viscoelasticity measurement of the polishing layer, the storage modulus E 'at 30℃' P30 Preferably 15X 10 7 ～65×10 7 Pa, more preferably 20X 10 7 ～60×10 7 Pa, more preferably 25X 10 7 ～55×10 7 Pa. By letting the storage modulus E' P30 Within the above range, the surface quality of the resulting polished object tends to be further improved.
In the dynamic viscoelasticity measurement of the polishing layer, the storage modulus E 'at 50℃' P50 Preferably 10X 10 7 ～40×10 7 Pa, more preferably 15X 10 7 ～35×10 7 Pa, more preferably 20X 10 7 ～30×10 7 Pa. By letting the storage modulus E' P50 Within the above range, the surface quality of the resulting polished object tends to be further improved.
2.1.2.2. Polyurethane sheet
Hereinafter, a polyurethane sheet is exemplified as an example of the polishing layer. The polyurethane sheet is described in embodiment 1, and thus description thereof is omitted.
2.1.3. Others
The polishing pad of embodiment 2 may have a buffer layer on the side of the polishing layer opposite to the polishing surface, or may have an adhesive layer between the polishing layer and the buffer layer on the surface of the buffer layer on the non-polishing layer side (the surface bonded to the polishing machine). In this case, the buffer layer and the adhesive layer have openings at the same positions as the positions of the polishing layer where the end point detection windows are located.
3. Embodiment 3
3.1. Polishing pad
The polishing pad of embodiment 3 has a polishing layer and an endpoint detection window provided in an opening of the polishing layer, and when a free induction decay curve of spin-spin relaxation of 1H obtained by measurement by the Solid Echo method using pulse NMR is separated into 3 curves of 3 components, i.e., a crystal phase, an intermediate phase, and an amorphous phase, from a short to long sequential waveform according to a relaxation time, a ratio of presence of the amorphous phase in the endpoint detection window Lw20 to presence of the amorphous phase in the polishing layer Lp20 (Lp 20/Lw 20) is 0.5 to 2.0, and a ratio of presence of the crystalline phase in the endpoint detection window Sw80 to presence of the crystalline phase in the polishing layer Sp80 (Sp 80/Sw 80) is 0.5 to 2.0.
In this way, the flatness can be improved from the viewpoint that the protruding portion is less likely to be generated during the dicing process, and from the viewpoint that the polishing layer is less likely to be excessively polished than the end point detection window during the trimming process, the flatness can be improved. In embodiment 3, these 2 types of flatness are collectively referred to simply as "flatness".
Fig. 1 is a schematic perspective view of a polishing pad according to embodiment 3. As shown in fig. 1, polishing pad 10 of embodiment 3 includes polishing layer 11 and end point detection window 12, and may include buffer layer 13 on the side opposite to polishing surface 11a, if necessary.
Fig. 2 to 3 show cross-sectional views of the periphery of the end point detection window 12 in fig. 1. As shown in fig. 2 to 3, an adhesive layer 14 may be provided between the polishing layer 11 and the buffer layer 13, and an adhesive layer 15 for bonding to the table 22 of fig. 4 may be provided on the surface of the buffer layer 13. In addition to the polishing surface 11a of the polishing pad of embodiment 3 being flat as shown in fig. 2, the polishing pad may have uneven shapes in which grooves 16 are formed as shown in fig. 3. The grooves 16 may be formed singly or in combination to form a plurality of grooves having various shapes such as concentric circles, lattices, and radial shapes.
3.1.1. Endpoint detection window
The end point detection window is a transparent member provided in the opening of the polishing layer, and serves as a light transmission path from the film thickness detection sensor in optical end point detection. In embodiment 3, the end point detection window is circular, but may be square, rectangular, polygonal, elliptical, or the like as necessary.
In embodiment 3, in the process of manufacturing the polishing pad, when dicing is performed, the end point detection window is suppressed from being recessed from the polishing layer, and from being broken, and the end point detection window is suppressed from being recessed from the polishing layer and protruding from the polishing layer during the dressing process, and from this point of view, the flatness is improved, and parameters relating to the end point detection window and the pulse NMR of the polishing layer are defined.
3.1.1.1. Pulsed NMR
Pulse NMR is one of solid NMR, which is a method of detecting a response signal to a pulse to determine a sample 1 H nuclear magnetic resonance relaxation time (an indicator of the mobility of a molecule). As a response to the pulse, a free induction decay signal (free induction decay: FID signal) is used.
Pulse NMR is an analytical method for evaluating the mobility of the system as a whole of a polymer molecular chain, and the mobility can be evaluated by measuring the relaxation time of a resin composition and the signal intensity at that time. In general, the lower the mobility of the polymer chain, the shorter the relaxation time, and therefore the faster the decay of the signal intensity, the relative signal intensity decreases in a short time when the initial signal intensity is set to 100%. Further, the higher the mobility of the polymer chain, the longer the relaxation time, and therefore the attenuation of the signal intensity becomes slow, and the relative signal intensity when the initial signal intensity is set to 100% gradually decreases over a long period of time.
For example, when measuring a resin, the obtained FID is the sum of FIDs of a plurality of components having different relaxation times, and the relaxation times of the components can be detected by separating the FIDs by using a least squares method. If the free induction decay curve at a predetermined temperature obtained by measurement by the solid echo method of pulse NMR is approximated by 3 components, it is possible to classify whether a signal obtained by the measurement is from the component having the lowest mobility (crystal phase), the intermediate component having the highest mobility (intermediate phase) and the component having the highest mobility (amorphous phase) in the sample, and the presence ratio of these components can be obtained.
Specifically, by fitting a free induction decay curve measured by a solid echo method of pulse NMR using the following formula (1), 3 components, i.e., a crystal phase, an intermediate phase, and an amorphous phase, can be approximated, and by approximating these 3 components, the respective component ratios can be obtained.
M(t)＝αexp(-(1/2)(t/T α ) 2 )sinbt/bt+βexp(-(1/Wa)(t/T β ) Wa )+γexp(-t/T γ ) (1)
Alpha: composition ratio of crystalline phase
T α : relaxation time of crystalline phase (unit: msec)
Beta: composition fraction of mesophase
T β : relaxation time of mesophase (units: msec)
Gamma: composition ratio of amorphous phase
T γ : relaxation time of amorphous phase (unit: msec)
t: observation time (Unit: msec)
Wa: form factor
b: form factor
From the measurement results of such pulse NMR, the mobility of the polishing layer and the endpoint detection window can be evaluated. In embodiment 3, the polishing layer and the endpoint detection window were evaluated for their approaching mobility by pulse NMR at a temperature of 20 ℃ corresponding to the dressing and at a temperature of 80 ℃ corresponding to the slicing.
Specifically, the ratio of the presence ratio Lw20 of the amorphous phase of the end point detection window to the presence ratio Lp20 of the amorphous phase of the polishing layer (Lp 20/Lw 20) at 20℃is 0.5 to 2.0, preferably 0.6 to 1.7, more preferably 0.7 to 1.5, and even more preferably 0.8 to 1.2. When the ratio (Lp 20/Lw 20) is within the above range, the mobility of each of the materials constituting the polishing layer and the end point detection window becomes close to each other during dressing. Therefore, the polishing layer and the end point detection window can be uniformly processed in the dressing process, and the flatness after the dressing process can be further improved.
The ratio of the presence ratio Sw80 of the crystal phase of the end point detection window to the presence ratio Sp80 of the crystal phase of the polishing layer (Sp 80/Sw 80) at 80℃is 0.5 to 2.0, preferably 0.6 to 1.7, more preferably 0.9 to 1.5, and even more preferably 1.0 to 1.3. When the ratio (Sp 80/Sw 80) is within the above range, the mobility of each of the materials constituting the polishing layer and the end point detection window in the dicing is close to each other. Therefore, the polishing layer and the end point detection window can be uniformly processed in the dicing process, and the flatness after the dicing process can be further improved.
The ratio of the intermediate phase present in the end point detection window at 20 ℃ to the intermediate phase present in the polishing layer (Mp 20/Mw 20) is preferably 0.7 to 1.5, more preferably 0.7 to 1.3, and even more preferably 0.7 to 1.1. When the ratio (Mp 20/Mw 20) is within the above range, the polishing layer and the end point detection window can be uniformly treated in the dressing treatment, and the flatness after the dressing treatment tends to be further improved.
The ratio of the intermediate phase present in the end point detection window to the intermediate phase present in the polishing layer (Mp 80/Mw 80) at 80 ℃ is preferably 0.5 to 1.5, more preferably 0.7 to 1.4, and even more preferably 0.8 to 1.3. When the ratio (Mp 80/Mw 80) is within the above range, the polishing layer and the end point detection window can be uniformly processed in the dicing process, and the flatness after the dicing process tends to be further improved.
The difference between the presence ratio Lw20 and the presence ratio Lp20 (|Lp20-Lw20|) is preferably 10 or less, more preferably 0 to 8.0, and still more preferably 0 to 5.0. By setting the difference (|Lp20-Lw20|) to be within the above range, the polishing layer and the end point detection window can be uniformly processed in the dressing process, and the flatness after the dressing process tends to be further improved.
The difference between the presence ratio Sw80 and the presence ratio Sw80 (|sp 80-Sw 80|) is preferably 15 or less, more preferably 0 to 12, and still more preferably 0 to 8.0. By setting the difference (|sp 80-Sw 80|) to be within the above range, the polishing layer and the end point detection window can be uniformly processed in the dicing process, and the flatness after the dicing process tends to be further improved.
The presence ratio Sw20 of the crystal phase of the end point detection window at 20℃is preferably 30 to 65%, more preferably 35 to 60%, and even more preferably 40 to 55%.
The intermediate phase of the end point detection window at 20℃is preferably present in a ratio Mw20 of 15 to 45%, more preferably 20 to 40%, even more preferably 25 to 35%.
The presence ratio Lw20 of the amorphous phase of the end point detection window at 20℃is preferably 10 to 40%, more preferably 15 to 35%, and even more preferably 20 to 30%.
By setting the presence ratio Sw20, the presence ratio Mw20, and the presence ratio Lw20 of the endpoint detection window at 20 ℃ to be within the above ranges, the polishing layer and the endpoint detection window can be uniformly treated in the dressing treatment, and the flatness after the dressing treatment tends to be further improved. The sum of the presence ratio Sw20, the presence ratio Mw20, and the presence ratio Lw20 is 100%.
The crystal phase presence ratio Sw80 of the end point detection window at 80℃is preferably 15 to 50%, more preferably 20 to 45%, and even more preferably 25 to 40%.
The intermediate phase of the end point detection window at 80℃is preferably present in a ratio Mw80 of 10 to 35%, more preferably 15 to 30%, even more preferably 20 to 25%.
The presence ratio Lw80 of the amorphous phase in the end point detection window at 80℃is preferably 30 to 60%, more preferably 35 to 55%, and even more preferably 40 to 50%.
By setting the presence ratio Sw80, the presence ratio Mw80, and the presence ratio Lw80 of the endpoint detection window at 80 ℃ to be in the above ranges, the polishing layer and the endpoint detection window can be uniformly processed in the dicing process, and the flatness after the dicing process tends to be further improved. The sum of the presence ratio Sw80, the presence ratio Mw80, and the presence ratio Lw80 is 100%.
The measurement conditions for pulse NMR measurement are not particularly limited, and measurement can be performed under the conditions described in examples.
3.1.1.3. Constituent material
The material constituting the end point detection window is not particularly limited as long as it is a transparent member capable of functioning as a window, and examples thereof include polyurethane resin WI, polyvinyl chloride resin, polyvinylidene fluoride resin, polyethersulfone resin, polystyrene resin, polyethylene resin, polytetrafluoroethylene resin, and the like. Among them, polyurethane resin WI is preferable. By using such a resin, the pulse NMR characteristics and transparency can be more easily adjusted, and the flatness can be further improved.
The polyurethane resin WI may be synthesized from a polyisocyanate and a polyol, and contains a structural unit derived from the polyisocyanate and a structural unit derived from the polyol.
3.1.1.3.1. Structural units derived from polyisocyanates
The structural unit derived from the polyisocyanate is not particularly limited, and examples thereof include a structural unit derived from an alicyclic isocyanate, a structural unit derived from an aliphatic isocyanate, and a structural unit derived from an aromatic isocyanate. Among them, the urethane resin WI preferably contains a structural unit derived from an alicyclic isocyanate and/or an aliphatic isocyanate, and more preferably contains a structural unit derived from an aliphatic isocyanate. Accordingly, the values related to pulse NMR can be easily adjusted to the above ranges, and the flatness at trimming and slicing can be further improved in addition to further improvement in transparency.
The alicyclic isocyanate, aliphatic isocyanate, and aromatic isocyanate are not particularly limited, and examples thereof include the compounds exemplified in embodiment 1.
3.1.1.3.2. Structural units derived from polyols
The structural unit derived from a polyol is not particularly limited, and examples thereof include a low molecular polyol having a molecular weight of less than 300 and a high molecular polyol having a molecular weight of 300 or more.
The low-molecular polyol is not particularly limited, and examples thereof include the compounds exemplified in embodiment 1.
Among them, a low molecular polyol having 3 or more hydroxyl groups is preferable, and glycerin is more preferable. By using such a low molecular weight polyol, the pulse NMR characteristic can be easily adjusted within the above range, and the abrasion loss can be adjusted, so that the flatness can be further improved, and the yellowing resistance of the window tends to be further improved in addition to the transparency.
The content of the structural unit derived from the low-molecular polyol having 3 or more hydroxyl groups is preferably 8.0 to 30 parts by mass, more preferably 10 to 25 parts by mass, and still more preferably 12.5 to 20 parts by mass relative to 100 parts by mass of the structural unit derived from the polyisocyanate. By setting the content of the structural unit derived from the low-molecular polyol having 3 or more hydroxyl groups within the above-described range, the pulse NMR characteristics can be easily adjusted to the above-described range, and the flatness can be further improved, and the yellowing resistance of the window tends to be further improved in addition to the transparency.
The polymer polyol is not particularly limited, and examples thereof include the compounds exemplified in embodiment 1.
The number average molecular weight of the polymer polyol is preferably 300 to 3000, more preferably 500 to 2500. By using such a polymer polyol, the pulse NMR properties tend to be easily adjusted to the above range.
Among them, polyether polyols are preferable, and poly (oxytetramethylene) glycol is more preferable. By using such a polymer polyol, the pulse NMR characteristics can be easily adjusted to the above range. In addition, the flatness can be further improved, and the transparency can be further improved, and the yellowing resistance of the window tends to be further improved.
The content of the structural unit derived from the polyether polyol is preferably 60 to 130 parts by mass, more preferably 65 to 120 parts by mass, and still more preferably 70 to 110 parts by mass, relative to 100 parts by mass of the structural unit derived from the polyisocyanate. By setting the content of the structural unit derived from the polyether polyol to the above range, the pulse NMR characteristic can be easily adjusted to the above range, and the flatness can be further improved, and the yellowing resistance of the window tends to be further improved in addition to the transparency.
Further, as the polyol, a low molecular polyol and a high molecular polyol are preferably used in combination, and a low molecular polyol having 3 or more hydroxyl groups and a polyether polyol are more preferably used in combination. Thus, the pulse NMR characteristics can be easily adjusted to the above range. In addition, the flatness can be further improved, and the transparency can be further improved, and the yellowing resistance of the window tends to be further improved.
From the above viewpoints, the content of the polyether polyol is preferably 2.0 to 15.0 parts, more preferably 3.0 to 12.5 parts, and even more preferably 4.0 to 9.0 parts, relative to 1 part of the low-molecular polyol having 3 or more hydroxyl groups.
3.1.2. Polishing layer
The polishing layer of embodiment 3 has an opening in which the end point detection window is buried. The position of the opening is not particularly limited, but is preferably set at a position in the radial direction corresponding to the film thickness detection sensor 23 provided on the stage 22. The number of openings is not particularly limited, but a plurality of openings are preferably provided at the same radial position so that the window passes through the film thickness detection sensor 23 a plurality of times when the polishing pad 10 attached to the table 22 rotates once.
The polishing layer is not particularly limited, and examples thereof include a resin foam molded body, a non-foam molded body, a resin impregnated base material in which a fiber base material is impregnated with a resin, and the like.
Here, the resin foam, the non-foam, the resin impregnated base material, and the fiber base material are described in embodiment 1, and thus description thereof is omitted.
3.1.2.1. Pulsed NMR
The crystal phase presence ratio Sp20 of the polishing layer is preferably 40 to 65%, more preferably 45 to 60%, and most preferably 50 to 55%.
The intermediate phase of the polishing layer is preferably present at a ratio Mp20 of 10 to 40%, preferably 15 to 35%, preferably 20 to 30%.
The amorphous phase of the polishing layer is preferably present at a ratio Lp20 of 10 to 35%, preferably 15 to 30%, preferably 20 to 25%.
By setting the presence ratio Sp20, the presence ratio Mp20, and the presence ratio Lp20 of the endpoint detection window at 20 ℃ to be within the above ranges, the polishing layer and the endpoint detection window can be uniformly treated in the dressing treatment, and the flatness after the dressing treatment tends to be further improved. The sum of the presence ratio Sp20, the presence ratio Mp20, and the presence ratio Lp20 is 100%.
The crystal phase of the polishing layer is preferably present at a ratio Sp80 of 25 to 50%, preferably 30 to 45%, preferably 35 to 40%.
The intermediate phase of the polishing layer is preferably present at a ratio Mp80 of 10 to 40%, preferably 15 to 35%, preferably 20 to 30%.
The amorphous phase of the polishing layer is preferably present at a ratio Lp80 of 25 to 50%, preferably 30 to 45%, and preferably 35 to 40%.
By setting the presence ratio Sp80, the presence ratio Mp80, and the presence ratio Lp80 of the endpoint detection window at 80 ℃ to be within the above ranges, the polishing layer and the endpoint detection window can be uniformly processed in the dicing process, and the flatness after the dicing process tends to be further improved. The sum of the presence ratio Sp80, the presence ratio Mp80, and the presence ratio Lp80 is 100%.
The measurement conditions for pulse NMR measurement are not particularly limited, and measurement can be performed under the conditions described in examples.
3.1.2.2. Polyurethane sheet
Hereinafter, a polyurethane sheet is exemplified as an example of the polishing layer. The polyurethane sheet is described in embodiment 1, and thus description thereof is omitted.
3.1.3. Others
The polishing pad of embodiment 3 may have a buffer layer on the side of the polishing layer opposite to the polishing surface, or may have an adhesive layer between the polishing layer and the buffer layer on the surface of the buffer layer on the non-polishing layer side (the surface bonded to the polishing machine). In this case, the buffer layer and the adhesive layer have openings at the same positions as the positions of the polishing layer where the end point detection windows are located.
4. Embodiment 4
4.1. Polishing pad
The polishing pad of embodiment 4 has a polishing layer and an end point detection window provided in an opening of the polishing layer, and in dynamic viscoelasticity measurement performed in a stretching mode at a frequency of 1.6Hz and under conditions of 30 to 55 ℃ and a immersed state, a ratio (E 'p40/E' w 40) of a storage modulus E 'w40 of the end point detection window at 40 ℃ to a storage modulus E' p40 of the polishing layer at 40 ℃ is 0.70 to 3.00.
Thus, since the dynamic viscoelasticity characteristics of the polishing layer and the endpoint detection window become closer to each other during polishing, even when the endpoint detection window, which is a heterogeneous member, is embedded in the polishing layer, occurrence of defects (surface defects) on the surface of the object to be polished can be further suppressed. Therefore, an object to be polished having excellent surface quality can be obtained.
Fig. 1 is a schematic perspective view of a polishing pad according to embodiment 4. As shown in fig. 1, polishing pad 10 of embodiment 4 includes polishing layer 11 and end point detection window 12, and may include buffer layer 13 on the side opposite to polishing surface 11a, if necessary.
Fig. 2 to 3 show cross-sectional views of the periphery of the end point detection window 12 in fig. 1. As shown in fig. 2 to 3, an adhesive layer 14 may be provided between the polishing layer 11 and the buffer layer 13, and an adhesive layer 15 for bonding to the table 22 of fig. 4 may be provided on the surface of the buffer layer 13. The polishing surface 11a of the polishing pad of embodiment 4 may be uneven as shown in fig. 3, in which grooves 16 are formed, in addition to being flat as shown in fig. 2. The grooves 16 may be formed singly or in combination to form a plurality of grooves having various shapes such as concentric circles, lattices, and radial shapes.
4.1.1. Endpoint detection window
The end point detection window is a transparent member provided in the opening of the polishing layer, and serves as a light transmission path from the film thickness detection sensor in optical end point detection. In embodiment 4, the end point detection window is circular, but may be square, rectangular, polygonal, elliptical, or the like as necessary.
In embodiment 4, the ratio of the storage modulus E' of the end point detection window to the polishing layer is defined from the standpoint of adjusting the degree of abrasion between the end point detection window and the polishing layer at the time of polishing, or the like, and causing one of the end point detection window and the polishing layer to be excessively polished to cause defects (surface defects) in a non-polished object.
4.1.1.1. Dynamic viscoelasticity
The storage modulus E' of the polishing layer and the end point detection window in embodiment 4 can be obtained by dynamic viscoelasticity measurement under conditions of a stretching mode, a frequency of 1.6Hz, 30 to 55 ℃ and a water immersion state. In the present embodiment, unless otherwise specified, it is assumed that the dynamic viscoelasticity measurement is performed in a water-immersed state.
In the polishing step in which the slurry is brought into contact with the polishing pad, the polishing surface is in a submerged state. Thus, in embodiment 4, the ratio of the dynamic viscoelasticity of the polishing layer to the endpoint detection window in the immersed state is defined at 40 ℃. More specifically, in the dynamic viscoelasticity measurement performed in the stretching mode at a frequency of 1.6Hz and in a wet state at 30 to 55 ℃, the ratio (E 'p40/E' w 40) of the storage modulus E 'w40 of the end point detection window at 40 ℃ to the storage modulus E' p40 of the polishing layer at 40 ℃ is defined.
The ratio (E 'p40/E' w 40) is 0.70 to 3.00, preferably 0.80 to 2.50, more preferably 0.90 to 2.00. When the ratio (E 'p40/E' w 40) is within the above range, the characteristics of the polishing layer and the end point detection window during polishing are similar, and thus the surface quality of the resulting polished object is further improved. This makes the contact state with the workpiece (workpiece) during polishing more optimal, and suppresses continuous pressing of the polishing dust and occurrence of scratches.
In the dynamic viscoelasticity measurement in the immersed state, the ratio (E 'p50/E' w 50) of the storage modulus E 'w50 of the end point detection window at 50 ℃ to the storage modulus E' p50 of the polishing layer at 50 ℃ is preferably 0.70 to 5.00, more preferably 0.80 to 4.00, and even more preferably 0.90 to 3.00. When the ratio (E 'p50/E' w 50) is within the above range, the characteristics of the polishing layer and the end point detection window during polishing are similar, and thus the surface quality of the resulting polished object tends to be further improved.
In the dynamic viscoelasticity measurement in the immersed state, the difference between the loss factor tan δw30 of the end point detection window at 30 ℃ and the loss factor tan δp30 of the polishing film at 30 ℃ (|tan δw30-tan δp30|) is preferably 0 to 0.30, more preferably 0.05 to 0.30, and even more preferably 0.05 to 0.20.
In the dynamic viscoelasticity measurement in the immersed state, the difference between the loss factor tan δw40 of the end point detection window at 40 ℃ and the loss factor tan δp40 of the polishing film at 40 ℃ (|tan δw40-tan δp40|) is preferably 0 to 0.40, more preferably 0.05 to 0.40, and even more preferably 0.05 to 0.30.
In the dynamic viscoelasticity measurement in the immersed state, the difference between the loss factor tan δw50 of the end point detection window at 50 ℃ and the loss factor tan δp50 of the end point detection window at 50 ℃ (|tan δw50-tan δp50|) is preferably 0 to 0.50, more preferably 0.05 to 0.50, and even more preferably 0.05 to 0.40.
By setting the difference (|tan δw30-tan δp30|), the difference (|tan δw40-tan δp40|), and the difference (|tan δw50-tan δp50|) within the above ranges, respectively, the characteristics of the end point detection window at the time of polishing are similar to the characteristics of the end point detection window at the time of polishing, and thus the surface quality of the resulting polished object tends to be further improved.
The storage modulus E' w40 at 40℃of the end point detection window in the immersed state is preferably 6.0 to 50X 10 7 Pa, more preferably 8.0 to 40X 10 7 Pa, more preferably 10 to 30X 10 7 Pa。
Storage modulus E 'at 50 ℃ of end point detection window in immersed state' w50 Preferably 2.0 to 40X 10 7 Pa, more preferably 3.0 to 30X 10 7 Pa, more preferably 4.0 to 20X 10 7 Pa。
The tan δw40 at 40℃of the end point detection window in the immersed state is preferably 0.1 to 0.7, more preferably 0.1 to 0.6, and still more preferably 0.1 to 0.5.
The tan δw50 at 50℃of the end point detection window in the immersed state is preferably 0.1 to 0.6, more preferably 0.1 to 0.5, and still more preferably 0.1 to 0.4.
By setting E 'w40, E' w50, tan δw40, and tan δw50 to the above ranges, the characteristics of the endpoint detection window and the polishing layer during polishing are similar, and thus the surface quality of the resulting polished object tends to be further improved.
The measurement conditions for the dynamic viscoelasticity measurement are not particularly limited, and the measurement can be performed by the conditions described in examples.
4.1.1.3. Constituent material
The material constituting the end point detection window is not particularly limited as long as it is a transparent member capable of functioning as a window, and examples thereof include polyurethane resin WI, polyvinyl chloride resin, polyvinylidene fluoride resin, polyethersulfone resin, polystyrene resin, polyethylene resin, polytetrafluoroethylene resin, and the like. Among them, polyurethane resin WI is preferable. By using such a resin, the dynamic viscoelastic properties and transparency can be more easily adjusted, and the surface quality can be further improved.
The polyurethane resin WI may be synthesized from a polyisocyanate and a polyol, and contains a structural unit derived from the polyisocyanate and a structural unit derived from the polyol.
4.1.1.3.1. Structural units derived from polyisocyanates
The structural unit derived from the polyisocyanate is not particularly limited, and examples thereof include a structural unit derived from an alicyclic isocyanate, a structural unit derived from an aliphatic isocyanate, and a structural unit derived from an aromatic isocyanate. Among them, the urethane resin WI preferably contains a structural unit derived from an alicyclic isocyanate and/or an aliphatic isocyanate, and more preferably contains a structural unit derived from an aliphatic isocyanate. Accordingly, the dynamic viscoelasticity characteristics can be easily adjusted to the above range, and the transparency is further improved, and the surface quality is also further improved.
The alicyclic isocyanate, aliphatic isocyanate, and aromatic isocyanate are not particularly limited, and examples thereof include the compounds exemplified in embodiment 1.
4.1.1.3.2. Structural units derived from polyols
The structural unit derived from a polyol is not particularly limited, and examples thereof include a low molecular polyol having a molecular weight of less than 300 and a high molecular polyol having a molecular weight of 300 or more.
The low-molecular polyol is not particularly limited, and examples thereof include the compounds exemplified in embodiment 1.
Among them, a low molecular polyol having 3 or more hydroxyl groups is preferable, and glycerin is more preferable. By using such a low-molecular polyol, dynamic viscoelasticity can be easily adjusted within the above range, and the abrasion amount can be adjusted, and the transparency is further improved, and the surface quality tends to be further improved.
The content of the structural unit derived from the low-molecular polyol having 3 or more hydroxyl groups is preferably 7.5 to 30 parts by mass, more preferably 10 to 25 parts by mass, and still more preferably 12.5 to 20 parts by mass relative to 100 parts by mass of the structural unit derived from the polyisocyanate. By setting the content of the structural unit derived from the low-molecular polyol having 3 or more hydroxyl groups to be within the above range, it is easy to adjust the dynamic viscoelasticity characteristics to be within the above range, and there is a tendency that the transparency is further improved and the surface quality is further improved.
The polymer polyol is not particularly limited, and examples thereof include the compounds exemplified in embodiment 1.
The number average molecular weight of the polymer polyol is preferably 300 to 3000, more preferably 500 to 2500. By using such a polymer polyol, dynamic viscoelasticity tends to be easily adjusted to the above range.
Among them, polyether polyols are preferable, and poly (oxytetramethylene) glycol is more preferable. By using such a polymer polyol, the dynamic viscoelasticity can be easily adjusted to the above range. In addition, there is a tendency that the yellowing resistance of the window is further improved in addition to the transparency.
The content of the structural unit derived from the polyether polyol is preferably 60 to 130 parts by mass, more preferably 65 to 120 parts by mass, and still more preferably 70 to 110 parts by mass, relative to 100 parts by mass of the structural unit derived from the polyisocyanate. By setting the content of the structural unit derived from the polyether polyol to be within the above range, the dynamic viscoelasticity characteristics can be easily adjusted to be within the above range, and the transparency and yellowing resistance of the window can be further improved.
Further, as the polyol, a low molecular polyol and a high molecular polyol are preferably used in combination, and a low molecular polyol having 3 or more hydroxyl groups and a polyether polyol are more preferably used in combination. Thus, the dynamic viscoelasticity characteristics are easily adjusted to the above range, and the transparency is further improved, and the yellowing resistance of the window is also further improved.
From the above viewpoints, the content of the polyether polyol is preferably 2.0 to 15.0 parts, more preferably 3.0 to 12.5 parts, and even more preferably 4.0 to 9.0 parts, relative to 1 part of the low-molecular polyol having 3 or more hydroxyl groups.
4.1.2. Polishing layer
The polishing layer of embodiment 4 has an opening in which the end point detection window is buried. The position of the opening is not particularly limited, but is preferably set at a position in the radial direction corresponding to the film thickness detection sensor 23 provided on the stage 22. The number of openings is not particularly limited, but a plurality of openings are preferably provided at the same radial position so that the window passes through the film thickness detection sensor 23 a plurality of times when the polishing pad 10 attached to the table 22 rotates once.
The polishing layer is not particularly limited, and examples thereof include a resin foam molded body, a non-foam molded body, a resin impregnated base material in which a fiber base material is impregnated with a resin, and the like.
Here, the resin foam, the non-foam, the resin impregnated base material, and the fiber base material are described in embodiment 1, and thus description thereof is omitted.
4.1.2.1. Dynamic viscoelasticity
The storage modulus E' p40 at 40℃of the polishing layer in the immersed state is preferably 10 to 40X 10 7 Pa, more preferably 15 to 35X 10 7 Pa, more preferably 20 to 30X 10 7 Pa。
Storage modulus E 'at 50 ℃ of the polishing layer in the immersed state' p50 Preferably 50 to 35X 10 7 Pa, more preferably 10 to 30X 10 7 Pa, more preferably 15 to 25X 10 7 Pa。
The polishing layer in the immersed state preferably has a tan δp40 of 0.01 to 0.25, more preferably 0.03 to 0.20, and still more preferably 0.05 to 0.15 at 40 ℃.
The polishing layer in the immersed state preferably has a tan δp50 at 50℃of 0.01 to 0.25, more preferably 0.03 to 0.20, and still more preferably 0.05 to 0.15.
By letting E' p40 、E’ p50 、tanδ p40 Tan delta p50 In the above ranges, the characteristics of the polishing layer and the end point detection window at the time of polishing are similar, and thus the surface quality of the resulting polished object tends to be further improved.
4.1.2.2. Polyurethane sheet
Hereinafter, a polyurethane sheet is exemplified as an example of the polishing layer. The polyurethane sheet is described in embodiment 1, and thus description thereof is omitted.
4.1.3. Others
The polishing pad of embodiment 4 may have a buffer layer on the side of the polishing layer opposite to the polishing surface, or may have an adhesive layer between the polishing layer and the buffer layer on the surface of the buffer layer on the non-polishing layer side (the surface bonded to the polishing machine). In this case, the buffer layer and the adhesive layer have openings at the same positions as the positions of the polishing layer where the end point detection windows are located.
5. Method for manufacturing polishing pad
The method for producing the polishing pad according to embodiments 1 to 4 is not particularly limited, and includes, for example, the following steps: filling a mold to which a window member serving as an end point detection window is fixed with a resin composition constituting a polishing layer, and curing the resin composition to obtain a resin block in which the window member is buried; and a step of slicing the obtained resin block to obtain a polyurethane sheet having an end point detection window at the opening, wherein the polished surface of the obtained polyurethane sheet may be subjected to a finishing treatment in the production method, if necessary.
The temperature at the time of slicing is preferably 70℃to 100 ℃. The temperature in the finishing treatment is preferably 20 to 30 ℃. This tends to further improve the flatness.
6. Method for producing polished product
The method for producing a polishing product according to embodiments 1 to 4 includes a polishing step of polishing an object to be polished with the polishing pad in the presence of a polishing slurry to obtain a polishing product; and an end point detection step of performing end point detection by an optical end point detection method during the polishing.
6.1. Grinding process
The polishing step may be a primary polishing (rough polishing), a secondary polishing (finish polishing), or a step combining these polishing steps. Here, "polishing" refers to polishing with coarse abrasive grains at a relatively high rate, and "polishing" refers to polishing with fine abrasive grains at a relatively low rate to improve the surface quality.
Among them, the polishing pads of embodiments 1 to 4 are preferably used for Chemical Mechanical Polishing (CMP). Hereinafter, the method for producing the polished object according to embodiment 1 to 4 will be described by taking chemical mechanical polishing as an example, but the method for producing the polished object according to embodiment 1 to 4 is not limited to the following.
The material to be polished is not particularly limited, and examples thereof include materials such as semiconductor devices and electronic components, and particularly thin substrates (materials to be polished) such as Si substrates (silicon wafers), siC substrates (silicon carbide), gaAs substrates (gallium arsenide) substrates, glass, hard disks, and substrates for LCDs (liquid crystal displays). Specifically, a semiconductor device having a metal wiring such as W (tungsten) or Cu (copper) is given.
The polishing method is not particularly limited, and conventionally known methods can be used. For example, first, an object to be polished held by a holding platen disposed so as to face the polishing pad is pressed against the polishing surface side, and the polishing pad and/or the holding platen are rotated while slurry is supplied from the outside. The polishing pad and the holding table may rotate in the same direction at different rotational speeds, or may rotate in different directions. In addition, the object to be polished may be polished while moving (rotating) inside the frame during the polishing.
The slurry contains chemical components such as water and an oxidizing agent typified by hydrogen peroxide, additives, and abrasive grains (abrasive grains; for example, siC and SiO) depending on the object to be polished, polishing conditions, and the like 2 、Al 2 O 3 、CeO 2 ) Etc.
6.2. Endpoint detection step
The method for producing a polished product according to embodiments 1 to 4 includes an end point detection step of performing end point detection by an optical end point detection method in the polishing step. As an end point detection method using the optical end point detection method, specifically, a conventionally known method can be used.
Fig. 4 is a schematic diagram showing an end point detection method of the optical end point detection method. In this schematic view, a chemical mechanical polishing process is shown in which the slurry 24 is flowed on the polishing pad 10 attached to the platen 22, and the wafer W held by the top ring 21 is pressed to grind and planarize the uneven film on the surface of the wafer W. In the polishing apparatus 20, a film thickness detection sensor 23 for monitoring the film thickness is mounted on the table 22 so as to finish the process with high accuracy in order to perform end point detection of a predetermined film thickness while flattening. The film thickness detection sensor 23 irradiates light onto the polishing surface of the wafer W, for example, and measures and analyzes the spectral intensity characteristics of the reflected light, thereby detecting the polishing end point.
More specifically, the film thickness detection sensor 23 is capable of detecting a film thickness change by detecting the intensity of reflection intensity generated by detecting a phase difference between light reflected by a film on the wafer W (wafer surface) and light reflected by an interface between the film on the wafer W and a substrate of the wafer by making light incident on the wafer W through the end point detection window 12.
Examples
Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. The present invention is not limited in any way by the following examples. The term "parts" refers to parts by mass.
[ example A ]
[ production example A1: endpoint detection window A1 ]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 78.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 650 and 14.8 parts of glycerin were reacted to obtain a transparent member serving as an end point detection window A1.
[ production example A2: endpoint detection window A2 ]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 78.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 650, 7.5 parts of glycerin and 7.5 parts of ethylene glycol were reacted to obtain a transparent member serving as an end point detection window A2.
[ production example 3: endpoint detection window A3 ]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 78.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 650, 4.5 parts of glycerin and 10.5 parts of ethylene glycol were reacted to obtain a transparent member serving as an end point detection window A3.
[ production example 4: endpoint detection window A4 ]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 103.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000 and 15.9 parts of glycerin were reacted to obtain a transparent member serving as an end point detection window A4.
[ example A1 ]
To 100 parts of a urethane prepolymer having an NCO equivalent of 455 obtained by reacting 2, 4-toluene diisocyanate (2, 4-TDI), poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 650, poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000, and diethylene glycol (DEG), 2.7 parts of unexpanded hollow fine particles (average particle diameter: 8.5 μm) having a mixed shell portion formed of an acrylonitrile-vinylidene chloride copolymer were added to obtain a urethane prepolymer mixture. The resulting urethane prepolymer mixture was placed in a1 st tank and incubated at 60 ℃. Separately from the 1 st liquid tank, 25.8 parts of 3,3 '-dichloro-4, 4' -diaminodiphenylmethane (methylenebis (o-chloroaniline) (MOCA) was added to the 2 nd liquid tank as a curing agent, and the mixture was heated and melted at 120 ℃ and mixed, followed by deaeration under reduced pressure to obtain a curing agent melt.
Next, the liquids of the 1 st liquid tank and the 2 nd liquid tank were injected from the respective injection ports of the mixer having 2 injection ports, and stirred and mixed to obtain a mixed liquid.
Then, the obtained mixed solution was cast into a mold provided with the end point detection window A1 obtained as described above in advance, and was once cured at 80 ℃ for 30 minutes. The formed block-shaped article was taken out of the mold, and was subjected to secondary curing at 120℃for 4 hours in an oven to obtain a polyurethane resin block. The obtained polyurethane resin block was naturally cooled to 25 ℃.
Then, the resultant sheet was subjected to slicing treatment after being heated again with an oven at 120℃for 5 hours, and the sliced surface was subjected to grinding (polishing) treatment as needed, to obtain a foamed polyurethane sheet. The polishing pad was obtained by attaching a double-sided tape to the back surface of the obtained polyurethane sheet, attaching a buffer layer, and further attaching a double-sided tape to the surface of the buffer layer.
In the case of evaluating the cross section around the end point detection window in the state after the dressing process, the polishing pad obtained as described above was subjected to the dressing process under the following conditions.
(trimming conditions)
Using a grinder: manufactured by Speedfam corporation under the trade name "FAM-12BS"
Platen rotation speed (rotation speed of polishing pad): 50rpm
Flow rate: 100ml/min (pure water at 20 ℃ C. Was dropped from the center of rotation of the polishing pad.)
Trimming machine: diamond finisher manufactured by 3M company, model "A188"
Finishing machine rotational speed: 100rpm
Trimming pressure: 0.115kg/cm 2
Rotational direction of the finisher: rotates in the same direction as the polishing pad
Test time: 60 minutes
[ comparative example A1 ]
A polishing pad was obtained in the same manner as in example A1, except that the end point detection window A2 of production example A2 was used.
[ comparative example A2 ]
A polishing pad was obtained in the same manner as in example A1, except that the end point detection window A3 of production example A3 was used.
[ example A2 ]
A polishing pad was obtained in the same manner as in example A1, except that the end point detection window A4 of production example A4 was used.
[ dynamic viscoelasticity measurement ]
Dynamic viscoelasticity measurement was performed under a normal air atmosphere (dry state) using a polyurethane sheet in a dry state in which the polyurethane sheet was held in a constant temperature and humidity tank at a temperature of 23 ℃ (±2 ℃) and a relative humidity of 50% (±5%) as a sample based on the following conditions. The end point detection window had sample dimensions of 5cm long by 0.5cm wide by 0.125cm thick, and the polishing layer had sample dimensions of 5cm long by 0.5cm wide by 0.13cm thick.
(measurement conditions)
Measurement device: RSA III (TA Instruments Co., ltd.)
Test length: 1cm
Test mode: stretching
Frequency: 1.0Hz
Temperature range: 10-100 DEG C
Heating rate: 3.0 ℃/min
Strain range: 0.10%
Initial load: 300g
Measurement interval: 1.5 Point/. Degree.C
[ D hardness ]
D hardness was measured according to JIS K6253. In the measurement, a D-durometer manufactured by TECLOCK was used, and the end point detection windows (thickness: about 0.125cm (1.25 mm)) described in comparative example A and example A were stacked by 4 pieces so that the total thickness of the samples was at least 0.45cm (4.5 mm). The sample was allowed to stand in a constant temperature and humidity tank at 20℃or 80℃for 30 minutes.
[ evaluation of section ]
For each pad obtained as described above, the cross section (evaluation A2) of the periphery of the end point detection window (the portion surrounded by the broken line S in fig. 2) in the state after dicing and before trimming and (the portion surrounded by the broken line S in fig. 2) of the periphery of the end point detection window (evaluation A1) in the state after trimming was enlarged 200 times by a laser microscope (VK-X1000, manufactured by KEYENCE corporation) in the range of about 14mm×1mm, and the surface of the diameter portion of the end point detection window was observed in the connected mode, and contour measurement of the height information was performed based on the obtained laser image.
The results are shown in fig. 5A to D and fig. 6A to D. Fig. 5A to D and 6A to D show the results of cross-sectional measurements of the end point detection windows at 2 points, and the results are also obtained by cross-sectional measurements of the end point detection windows in the slicing direction and in the direction perpendicular to the slicing direction.
In the evaluation A1, the end point detection window was evaluated as "o" if it was within ±50 μm from the polished surface, and otherwise, as "x". In the evaluation A2, the cross-sectional image was set to be flat (equal in height in the range from the end to the center) as o, and the cross-sectional image was set to be convex (higher in height in the range from the end to the center) as x.
TABLE 1
Example A1 Comparative example A1 Comparative example A2 Example A2
E’ W90 [×10 7 Pa] 1.54 0.53 0.40 3.40
E’ W30 [×10 7 Pa] 68.4 56.4 47.8 41.3
Peak temperature of tan delta [ DEGC] 79 65 61 86
D W８0 41.5 36.5 32.0 42.0
D W20 68.0 64.0 68.0 62.3
E’ P90 [×10 7 Pa] 10.5 10.5 10.5 10.5
E’ P90 -E’ WW90 [×10 7 Pa] 8.96 9.97 10.1 7.09
Flatness after slicing (evaluation A1) ○ × × ○
Flatness after trimming (evaluation A2) ○ × × ○
Example B
Production example B1: endpoint detection Window B1]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 120.9 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000 and 14.8 parts of glycerin were reacted to obtain a transparent member serving as an end point detection window B1.
Production example B2: endpoint detection Window B2]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 103.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000 and 15.9 parts of glycerin were reacted to obtain a transparent member serving as an end point detection window B2.
Production example B3: endpoint detection Window B3]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 96.7 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000 and 16.3 parts of glycerin were reacted to obtain a transparent member serving as an end point detection window B3.
Production example B4: endpoint detection Window B4]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 90.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000 and 16.7 parts of glycerin were reacted to obtain a transparent member serving as an end point detection window B4.
[ production example B5: endpoint detection window B5 ]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 78.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 650 and 14.8 parts of glycerin were reacted to obtain a transparent member serving as an end point detection window B5.
[ production example B6: endpoint detection window B6 ]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 78.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 650, 10.5 parts of ethylene glycol and 4.5 parts of glycerin were reacted to obtain a transparent member serving as an end point detection window B6.
[ example B1 ]
To 100 parts of a urethane prepolymer having an NCO equivalent of 455 obtained by reacting 2, 4-toluene diisocyanate (2, 4-TDI), poly (oxytetramethylene) glycol (PTMG) having an average molecular weight of 650, poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000, and diethylene glycol (DEG), 2.7 parts of unexpanded hollow fine particles (average particle diameter: 8.5 μm) having a mixed shell portion formed of an acrylonitrile-vinylidene chloride copolymer were added to obtain a urethane prepolymer mixture. The resulting urethane prepolymer mixture was placed in a 1 st tank and incubated at 60 ℃. Separately from the 1 st liquid tank, 25.8 parts of 3,3 '-dichloro-4, 4' -diaminodiphenylmethane (methylenebis (o-chloroaniline) (MOCA) was added to the 2 nd liquid tank as a curing agent, and the mixture was heated, melted and mixed at 120 ℃.
Next, the liquids in the 1 st liquid tank and the 2 nd liquid tank were injected from the respective injection ports of the mixer having 2 injection ports, and stirred and mixed to obtain a mixed liquid.
Then, the obtained mixed solution was cast into a mold provided with the end point detection window B1 obtained as described above in advance, and was once cured at 80 ℃ for 30 minutes. The formed block-shaped article was taken out of the mold, and was subjected to secondary curing at 120℃for 4 hours in an oven to obtain a polyurethane resin block. The obtained polyurethane resin block was naturally cooled to 25 ℃.
Then, the resultant sheet was heated again with an oven at 120℃for 5 hours, and then subjected to slicing treatment, and the sliced surface was subjected to grinding treatment (polishing) to obtain a foamed polyurethane sheet. The polishing pad was obtained by attaching a double-sided tape to the back surface of the obtained polyurethane sheet, attaching a buffer layer, and further attaching a double-sided tape to the surface of the buffer layer.
[ example B2 ]
To 100 parts of a urethane prepolymer having an NCO equivalent of 420 obtained by reacting 2, 4-toluene diisocyanate (2, 4-TDI), poly (oxytetramethylene) glycol (PTMG) having an average molecular weight of 650, poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000, and diethylene glycol (DEG), 2.9 parts of unexpanded hollow fine particles (average particle diameter: 8.5 μm) having a mixed shell portion formed of an acrylonitrile-vinylidene chloride copolymer were added to obtain a polyurethane prepolymer mixture. The resulting urethane prepolymer mixture was placed in a 1 st tank and incubated at 60 ℃. A polishing pad was obtained in the same manner as in example B1 except that 28.0 parts of 3,3 '-dichloro-4, 4' -diaminodiphenylmethane (methylenebis (o-chloroaniline) (MOCA) as a curing agent was added to the 2 nd liquid tank, and the mixture was heated, melted and mixed at 120 ℃ and further defoamed under reduced pressure to obtain a curing agent melt, and the curing agent melt and the end point detection window B2 were used.
[ example B3 ]
To 100 parts of a urethane prepolymer having an NCO equivalent of 460 obtained by reacting 2, 4-toluene diisocyanate (2, 4-TDI), poly (oxytetramethylene) glycol (PTMG) having an average molecular weight of 650 and diethylene glycol (DEG), 2.8 parts of expanded hollow fine particles (average particle diameter: 20 μm) having a mixed shell part formed of an acrylonitrile-vinylidene chloride copolymer were added to obtain a urethane prepolymer mixture. The resulting urethane prepolymer mixture was placed in a 1 st tank and incubated at 60 ℃. A polishing pad was obtained in the same manner as in example B1 except that 25.5 parts of 3,3 '-dichloro-4, 4' -diaminodiphenylmethane (methylenebis (o-chloroaniline)) and 8.5 parts of polypropylene glycol as a curing agent were added to the 2 nd liquid tank separately from the 1 st liquid tank, and the mixture was heated, melted and mixed at 120 ℃.
[ example B4 ]
A polishing pad was obtained in the same manner as in example B1, except that the end point detection window B2 was used.
[ example B5 ]
A polishing pad was obtained in the same manner as in example B1, except that the end point detection window B3 was used.
[ example B6 ]
A polishing pad was obtained in the same manner as in example B1, except that the end point detection window B4 was used.
[ example B7 ]
A polishing pad was obtained in the same manner as in example B2, except that the end point detection window B4 was used.
[ comparative example B1 ]
A polishing pad was obtained in the same manner as in example B1, except that the end point detection window B5 was used.
[ comparative example B2 ]
A polishing pad was obtained in the same manner as in example B1, except that the end point detection window B6 was used.
[ dynamic viscoelasticity measurement ]
Dynamic viscoelasticity was measured under a normal atmospheric atmosphere (dry state) using a polishing layer and an endpoint detection window in a constant temperature and humidity tank having a relative humidity of 50% (±5%) and a temperature of 23 ℃ (±2 ℃) as samples under the following conditions. The end point detection window had sample dimensions of 5cm long by 0.5cm wide by 0.125cm thick, and the polishing layer had sample dimensions of 5cm long by 0.5cm wide by 0.13cm thick.
(measurement conditions)
Measurement device: RSA III (TA Instruments Co., ltd.)
Test length: 1cm
Test mode: stretching
Frequency: 1.0Hz
Temperature range: 10-100 DEG C
Heating rate: 3.0 ℃/min
Strain range: 0.10%
Initial load: 300g
Measurement interval: 1.5 Point/. Degree.C
[ D hardness ]
The D hardness was measured according to JIS K6253. In the measurement, a D-durometer manufactured by TECLOCK was used, and the end point detection windows (thickness: about 0.125cm (1.25 mm)) described in comparative example B and example B were stacked by 4 pieces so that the total thickness of the samples was at least 0.45cm (4.5 mm). The sample was allowed to stand in a constant temperature and humidity tank at 20℃for 30 minutes.
[ evaluation B: surface quality verification test ]
The polishing pad was set at a predetermined position of the polishing apparatus via a double-sided tape having an acrylic adhesive, and the Cu film substrate was polished under the following conditions.
(grinding conditions)
Grinding machine: F-REX300X (manufactured by common Perilla seed production company)
Disk: a188 (manufactured by 3M company)
Rotational speed: (platform) 85rpm, (top ring) 86rpm
Grinding pressure: 3.5psi
Abrasive temperature: 20 DEG C
Abrasive discharge amount: 200ml/min
An abrasive: CSL-9044C (manufactured by FUJIMI CORPORATION Co.) (CSL-9044C uses a stock solution: pure water=a mixed solution of 1:9 by weight)
The object to be polished: cu film substrate
Grinding time: 60 seconds
Pad activation operation: 35N 10 min
And (3) adjusting: ex-situ,35N,4 scans
Defects (surface defects) of 155nm or more in size were detected and evaluated on the 10 th and 50 th sheets of the polished object after the polishing process using a high sensitivity measurement mode of a surface inspection apparatus (Surfscan SP2XP manufactured by KLA-Tencor corporation). The surface quality was evaluated based on the result of the confirmation of the defect (surface defect).
TABLE 2
[ example C ]
[ production example C1: endpoint detection window C1 ]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 90.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000 and 16.7 parts of glycerin were reacted to obtain a transparent member serving as an end point detection window C1.
[ production example C2: endpoint detection window C2 ]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 103.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000 and 15.9 parts of glycerin were reacted to obtain a transparent member serving as an end point detection window C2.
[ production example C3: endpoint detection window C3 ]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 78.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 650, 4.5 parts of glycerin and 10.5 parts of ethylene glycol were reacted to obtain a transparent member serving as an end point detection window C3.
[ example C1 ]
To 100 parts of a urethane prepolymer having NCO equivalent 420 obtained by reacting 2, 4-toluene diisocyanate (2, 4-TDI), poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 650, poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000 and diethylene glycol (DEG), 2.9 parts of unexpanded hollow fine particles (average particle diameter: 8.5 μm) having a mixed shell portion formed of an acrylonitrile-vinylidene chloride copolymer were added to obtain a polyurethane prepolymer mixture. The resulting urethane prepolymer mixture was placed in a 1 st tank and incubated at 60 ℃. Separately from the 1 st liquid tank, 28.0 parts of 3,3 '-dichloro-4, 4' -diaminodiphenylmethane (methylenebis (o-chloroaniline) (MOCA) as a curing agent was added to the 2 nd liquid tank, and the mixture was heated and melted at 120 ℃ and mixed, followed by deaeration under reduced pressure to obtain a curing agent melt.
Next, the liquids in the 1 st liquid tank and the 2 nd liquid tank were injected from the respective injection ports of the mixer having 2 injection ports, and stirred and mixed to obtain a mixed liquid.
Then, the obtained mixed solution was cast into a mold provided with the end point detection window C1 obtained as described above in advance, and was once cured at 80 ℃ for 30 minutes. The formed block-shaped article was taken out of the mold, and was subjected to secondary curing at 120℃for 4 hours in an oven to obtain a polyurethane resin block. The obtained polyurethane resin block was naturally cooled to 25 ℃.
Then, the resultant sheet was subjected to slicing treatment after being heated again with an oven at 120℃for 5 hours, and the sliced surface was subjected to grinding (polishing) treatment as needed, to obtain a foamed polyurethane sheet. The polishing pad was obtained by attaching a double-sided tape to the back surface of the obtained polyurethane sheet, attaching a buffer layer, and further attaching a double-sided tape to the surface of the buffer layer.
In the case of evaluating the cross section around the end point detection window in the state after the dressing process, the polishing pad obtained as described above was subjected to the dressing process under the following conditions.
(trimming conditions)
Using a grinder: manufactured by Speedfam corporation under the trade name "FAM-12BS"
Platen rotation speed (rotation speed of polishing pad): 50rpm
Flow rate: 100ml/min (pure water at 20 ℃ C. Was dropped from the center of rotation of the polishing pad.)
Trimming machine: diamond finisher manufactured by 3M company, model "A188"
Finishing machine rotational speed: 100rpm
Trimming pressure: 0.115kg/cm 2
Rotational direction of the finisher: rotates in the same direction as the polishing pad
Test time: 60 minutes
[ example C2 ]
A polishing pad was obtained in the same manner as in example C1, except that the end point detection window C2 of production example C3 was used.
[ comparative example C1 ]
A polishing pad was obtained in the same manner as in example C1, except that the end point detection window C3 of production example C3 was used.
[ pulse NMR ]
The device comprises: minispec MQ20 (Bruker Biospin, inc.)
Nuclear species: 1 H
and (3) measuring: t (T) 2
Assay: solid echo
Cumulative number of times: 256 times
Repetition time: 1.0 second
Measuring temperature: 20 ℃, 80 ℃ (the temperature of the device reaches the measurement temperature), 60 minutes after the sample is set, the measurement is started
Under the conditions of the device and the conditionsAbout 50mg of 10 pieces of sample particles were prepared and filled in a sample tube, and pulse NMR was measured to obtain an attenuation curve.
The obtained decay curve was fitted and analyzed by using the formula (1), and relaxation times of the crystalline phase, the intermediate phase, and the amorphous phase in the polyurethane resin were obtained. The fitting and analysis were performed using software attached to the measurement device.
M(t)＝αexp(-(1/2)(t/T α ) 2 )sinbt/bt+βexp(-(1/Wa)(t/T β ) Wa )+γexp(-t/T γ ) (1)
Alpha: composition ratio of crystalline phase
T α : relaxation time of crystalline phase (unit: msec)
Beta: composition fraction of mesophase
T β : relaxation time of mesophase (units: msec)
Gamma: composition ratio of amorphous phase
T γ : relaxation time of amorphous phase (unit: msec)
t: observation time (Unit: msec)
Wa: form factor
b: form factor
[ evaluation of section ]
For each pad obtained as described above, the cross section (evaluation C2) of the periphery of the end point detection window (the portion surrounded by the broken line S in fig. 2) in the state after dicing and before trimming and (the portion surrounded by the broken line S in fig. 2) of the periphery of the end point detection window (evaluation C1) in the state after trimming was enlarged 200 times by a laser microscope (VK-X1000, manufactured by KEYENCE corporation) in the range of about 14mm×1mm, and the surface of the diameter portion of the end point detection window was observed in the connected mode, and contour measurement of the height information was performed based on the obtained laser image.
The results are shown in fig. 7A to C and fig. 8A to C. Fig. 7A to C and 8A to C show the results of cross-sectional measurements of the end point detection windows at 2 points, and the results are also obtained by cross-sectional measurements of the end point detection windows in the slicing direction and in the direction perpendicular to the slicing direction.
In the evaluation C1, the end point detection window was evaluated as o if it was within ±50μm from the polished surface, and otherwise, as x. In the evaluation C2, the cross-sectional image was set to be flat (equal in height in the range from the end to the center) as o, and the cross-sectional image was set to be convex (higher in height in the range from the end to the center) as x.
TABLE 3
[ example D ]
[ production example D1: endpoint detection window D1 ]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 90.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000 and 16.7 parts of glycerin were reacted to obtain a transparent member serving as an end point detection window D1.
[ production example D2: endpoint detection window D2 ]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 103.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000 and 15.9 parts of glycerin were reacted to obtain a transparent member serving as an end point detection window D2.
[ production example D3: endpoint detection window D3 ]
100 parts of 4,4' -methylenebis (cyclohexyl isocyanate), 78.6 parts of poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 650, 4.5 parts of glycerin and 10.5 parts of ethylene glycol were reacted to obtain a transparent member serving as an end point detection window D3.
[ example D1 ]
To 100 parts of a urethane prepolymer having NCO equivalent 420 obtained by reacting 2, 4-toluene diisocyanate (2, 4-TDI), poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 650, poly (oxytetramethylene) glycol (PTMG) having a number average molecular weight of 1000 and diethylene glycol (DEG), 2.9 parts of unexpanded hollow fine particles (average particle diameter: 8.5 μm) having a mixed shell portion formed of an acrylonitrile-vinylidene chloride copolymer were added to obtain a polyurethane prepolymer mixture. The resulting urethane prepolymer mixture was placed in a 1 st tank and incubated at 60 ℃. Separately from the 1 st liquid tank, 28.0 parts of 3,3 '-dichloro-4, 4' -diaminodiphenylmethane (methylenebis (o-chloroaniline) (MOCA) as a curing agent was added to the 2 nd liquid tank, and the mixture was heated and melted at 120 ℃ and mixed, followed by deaeration under reduced pressure to obtain a curing agent melt.
Next, the liquids in the 1 st liquid tank and the 2 nd liquid tank were injected from the respective injection ports of the mixer having 2 injection ports, and stirred and mixed to obtain a mixed liquid.
Then, the obtained mixed solution was poured into a mold provided with the end point detection window D1 obtained as described above, and was cured once at 80 ℃ for 30 minutes. The formed block-shaped article was taken out of the mold, and was subjected to secondary curing at 120℃for 4 hours in an oven to obtain a polyurethane resin block. The obtained polyurethane resin block was naturally cooled to 25 ℃.
Then, the resultant sheet was subjected to slicing treatment after being heated again with an oven at 120℃for 5 hours, and the sliced surface was subjected to grinding (polishing) treatment as needed, to obtain a foamed polyurethane sheet. The polishing pad was obtained by attaching a double-sided tape to the back surface of the obtained polyurethane sheet, attaching a buffer layer, and further attaching a double-sided tape to the surface of the buffer layer.
[ dynamic viscoelasticity measurement ]
Dynamic viscoelasticity measurement was performed based on the following conditions. First, the sample was immersed in water at a temperature of 23℃for 3 days. Using the obtained sample, dynamic viscoelasticity measurement was performed in water (immersed state). The end point detection window had sample dimensions of 5cm long by 0.5cm wide by 0.13cm thick, and the polishing layer had sample dimensions of 5cm long by 0.5cm wide by 0.13cm thick.
(measurement conditions)
Measurement device: RSA G2 (TA Instruments Co., ltd.)
Test length: 1cm
Pretreatment of a sample: maintaining in water at 23deg.C for 3 days
Test mode: stretching
Frequency: 1.6Hz
Temperature range: 30-55 DEG C
Heating rate: 0.3 ℃/min
Strain range: 0.10%
Initial load: 300g
Measurement interval: 200 points/. Degree.C
[ surface quality test ]
The polishing pad was set at a predetermined position of the polishing apparatus via a double-sided tape having an acrylic adhesive, and the Cu film substrate was polished under the following conditions.
(grinding conditions)
Grinding machine: F-REX300X (manufactured by common Perilla seed production company)
Disk: a188 (manufactured by 3M company)
Rotational speed: (platform) 85rpm, (top ring) 86rpm
Grinding pressure: 3.5psi
Abrasive temperature: 20 DEG C
Abrasive discharge amount: 200ml/min
An abrasive: CSL-9044C (manufactured by FUJIMI CORPORATION Co.) (CSL-9044C uses a stock solution: pure water=a mixed solution of 1:9 by weight)
The object to be polished: cu film substrate
Grinding time: 60 seconds
Pad activation operation: 35N 10 min
And (3) adjusting: ex-situ,35N,4 scans
Defects (surface defects) of 155nm or more in size were detected and evaluated on the 10 th and 50 th sheets of the polished object after the polishing process using a high sensitivity measurement mode of a surface inspection apparatus (Surfscan SP2XP manufactured by KLA-Tencor corporation). The surface quality was evaluated based on the result of the confirmation of the defect (surface defect).
TABLE 4
In table 4, [ ratio p/w ] represents the ratio of the storage modulus E 'w of the end point detection window to the storage modulus E' p of the polishing layer at the same temperature, or the ratio of tan δw of the end point detection window to tan δp of the polishing layer. For example, according to Table 1, the ratio (E 'p40/E' w 40) of example D1 was 0.95, the ratio (E 'p40/E' w 40) of example D2 was 1.62, and the ratio (E 'p40/E' w 40) of comparative example D1 was 4.90.
In table 4, [ difference |p-w| ] represents the difference between the storage modulus E 'w of the end point detection window and the storage modulus E' p of the polishing sheet at the same temperature, or the difference between tan δw of the end point detection window and tan δp of the polishing sheet. For example, according to table 1, the difference (|tan δw30-tan δp30|) of example D1 was 0.07, the difference (|tan δw30-tan δp30|) of example D2 was 0.12, and the difference (|tan δw30-tan δp30|) of comparative example D1 was 0.34.
Industrial applicability
The polishing pad of the present invention is industrially applicable as a pad suitable for polishing a semiconductor wafer or the like.
Symbol description
10 … polishing pad, 11 … polishing layer, 11a … polishing surface, 12 … endpoint detection window, 13 … buffer layer, 14, 15 … adhesive layer, 16 … groove, 20 … polishing device, 21 … top ring, 22 … workbench, 23 … post mold detection sensor, 24 … slurry, W … wafer.

Claims (32)

1. A polishing pad having a polishing layer and an end point detection window provided in an opening of the polishing layer,
in the dynamic viscoelasticity measurement of the end point detection window performed in the stretching mode at a frequency of 1.0Hz and at a temperature of 10 to 100 ℃, the storage modulus E 'at 90℃' W90 Is 1.0X10 7 The pressure of the mixture is more than Pa,
d hardness (D W80 ) Is more than or equal to 40 percent,
d hardness (D W20 ) 40 to 90.
2. The polishing pad of claim 1, wherein the endpoint detection window comprises polyurethane resin WI.
3. The polishing pad according to claim 2, wherein the polyurethane resin WI contains structural units derived from an alicyclic isocyanate and/or an aliphatic isocyanate.
4. The polishing pad according to claim 2 or 3, wherein the polyurethane resin WI contains a structural unit derived from a compound having 3 or more hydroxyl groups.
5. The polishing pad of any one of claims 1-4, wherein the storage modulus E 'at 30 ℃ in the dynamic viscoelasticity measurement of the endpoint detection window' W30 60X 10 7 ～100×10 7 Pa。
6. The polishing pad according to any one of claims 1 to 5, wherein the peak temperature of tan δ is 70 to 100 ℃ in the dynamic viscoelasticity measurement of the end point detection window.
7. The polishing pad according to any one of claims 1 to 6, wherein the polishing layer comprises a polyurethane resin P and hollow fine particles dispersed in the polyurethane resin P.
8. A polishing pad having a polishing layer and an end point detection window provided in an opening of the polishing layer,
in the dynamic viscoelasticity measurement under the conditions of stretching mode, frequency 1.0Hz and 10-100 ℃, the storage modulus E 'of the end point detection window at 30℃' W30 Storage modulus E 'at 30 ℃ with the polishing layer' P30 Ratio (E ')' P30 /E’ W30 ) 0.60 to 1.50.
9. The polishing pad of claim 8, wherein the endpoint detection window comprises polyurethane resin WI.
10. The polishing pad according to claim 8, wherein the polyurethane resin WI contains structural units derived from an alicyclic isocyanate and/or an aliphatic isocyanate.
11. The polishing pad according to claim 9 or 10, wherein the polyurethane resin WI contains a structural unit derived from a compound having 3 or more hydroxyl groups.
12. The polishing pad of any one of claims 8-11, wherein in the dynamic viscoelasticity measurement, the endpoint detection window has a storage modulus E 'at 50 °c' W50 Storage modulus E 'at 50 ℃ with the polishing layer' P50 Ratio (E ')' P50 /E’ W50 ) 0.70 to 2.00.
13. The polishing pad of any one of claims 8-12, wherein in the dynamic viscoelasticity measurement of the endpoint detection window, the storage modulus E 'at 30 °c' W30 Is 10 multiplied by 10 7 ～60×10 7 Pa。
14. The polishing pad of any one of claims 8 to 13, wherein the endpoint detection window has a D hardness (D W20 ) 40 to 70.
15. The polishing pad according to any one of claims 8 to 14, wherein the polishing layer comprises a polyurethane resin P, and hollow fine particles dispersed in the polyurethane resin P.
16. A polishing pad having a polishing layer and an end point detection window provided in an opening of the polishing layer,
when the free induction decay curve of spin-spin relaxation of 1H obtained by measurement by the Solid Echo method using pulse NMR is separated into 3 curves from 3 components of a crystalline phase, an intermediate phase and an amorphous phase in a sequential waveform from short to long in relaxation time,
the ratio of the presence ratio Lw20 of the amorphous phase of the end point detection window to the presence ratio Lp20 of the amorphous phase of the polishing layer (Lp 20/Lw 20) at 20 ℃ is 0.5 to 2.0,
the ratio (Sp 80/Sw 80) of the presence ratio Sw80 of the crystal phase of the end point detection window to the presence ratio Sp80 of the crystal phase of the polishing layer at 80 ℃ is 0.5 to 2.0.
17. The polishing pad according to claim 16, wherein a ratio of an intermediate phase of the end point detection window to an intermediate phase of the polishing layer at 20 ℃ (Mp 20/Mw 20) is 0.7 to 1.5.
18. The polishing pad according to claim 16 or 17, wherein a ratio of an existence ratio Mw80 of the intermediate phase of the end point detection window to an existence ratio Mp80 of the intermediate phase of the polishing layer (Mp 80/Mw 80) at 80 ℃ is 0.5 to 1.5.
19. The polishing pad according to any one of claims 16 to 18, wherein a difference (|Lp20-Lw20|) between the presence ratio Lw20 and the presence ratio Lp20 is 10 or less.
20. The polishing pad according to any one of claims 16 to 19, wherein a difference (|sp 80-Sw 80|) between the presence ratio Sw80 and the presence ratio Sw80 is 15 or less.
21. The polishing pad of any one of claims 16 to 20, wherein the endpoint detection window comprises polyurethane resin WI,
the polyurethane resin WI contains structural units derived from aliphatic isocyanates.
22. The polishing pad according to claim 16 to 21, wherein the polishing layer comprises a polyurethane resin P,
the polyurethane resin P contains structural units derived from an aromatic isocyanate.
23. The polishing pad of any one of claims 16-22, wherein the polishing layer comprises hollow particles dispersed in the polishing layer.
24. A polishing pad having a polishing layer and an end point detection window provided in an opening of the polishing layer,
in the dynamic viscoelasticity measurement under conditions of a stretching mode, a frequency of 1.6Hz, 30-55 ℃ and a water-immersed state, the ratio (E 'p40/E' w 40) of the storage modulus E 'w40 of the end point detection window at 40 ℃ to the storage modulus E' p40 of the polishing layer at 40 ℃ is 0.70-3.00.
25. The polishing pad according to claim 24, wherein a ratio (E 'p50/E' w 50) of a storage modulus E 'w50 of the end point detection window at 50 ℃ to a storage modulus E' p50 of the polishing layer at 50 ℃ in the dynamic viscoelasticity measurement is 0.70 to 5.00.
26. The polishing pad according to claim 24 or 25, wherein a difference between a loss factor tan δw30 of the end point detection window at 30 ℃ and a loss factor tan δp30 of the polishing layer at 30 ℃ (|tan δw30-tan δp30|) in the dynamic viscoelasticity measurement is 0.05 to 0.30.
27. The polishing pad according to any one of claims 24 to 26, wherein a difference (|tanδw40-tanδp 40) between a loss factor tanδw40 of the endpoint detection window at 40 ℃ and a loss factor tanδp40 of the polishing layer at 40 ℃ in the dynamic viscoelasticity measurement is 0.05 to 0.40.
28. The polishing pad according to any one of claims 24 to 27, wherein a difference (|tanδw50-tanδp50|) between a loss factor tan δw50 of the endpoint detection window at 50 ℃ and a loss factor tan δp50 of the polishing layer at 50 ℃ in the dynamic viscoelasticity measurement is 0.05 to 0.50.
29. The polishing pad of any one of claims 24 to 28, wherein the endpoint detection window comprises polyurethane resin WI,
the polyurethane resin WI contains structural units derived from aliphatic isocyanates.
30. The polishing pad of any one of claim 24 to 29, wherein the polishing layer comprises a polyurethane resin P,
the polyurethane resin P contains structural units derived from an aromatic isocyanate.
31. The polishing pad of any one of claims 24-30, wherein the polishing layer comprises hollow particles dispersed in the polishing layer.
32. A method for producing a polished product, comprising:
a polishing step of polishing an object to be polished with the polishing pad according to any one of claims 1 to 31 in the presence of a polishing slurry to obtain a polished object; and
an end point detection step of performing end point detection by an optical end point detection method during the polishing.
CN202280024991.XA 2021-03-30 2022-03-24 Polishing pad and method for producing polished product Pending CN117120213A (en)

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JP2021-057002 2021-03-30
JP2021-057019 2021-03-30
JP2021057019A JP2022154128A (en) 2021-03-30 2021-03-30 Abrasive pad and polished product manufacturing method
PCT/JP2022/014016 WO2022210264A1 (en) 2021-03-30 2022-03-24 Polishing pad and method for manufacturing polished workpiece

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