WO2022210264A1

WO2022210264A1 - Polishing pad and method for manufacturing polished workpiece

Info

Publication number: WO2022210264A1
Application number: PCT/JP2022/014016
Authority: WO
Inventors: 哲平立野; 光紀糸山; 仁志関谷; 堅一小池; 浩栗原; さつき山口; 大和 ▲高▼見沢
Original assignee: 富士紡ホールディングス株式会社
Priority date: 2021-03-30
Filing date: 2022-03-24
Publication date: 2022-10-06
Also published as: TW202307050A; KR20230162661A

Abstract

This polishing pad includes: a polyurethane sheet serving as a polishing layer; and an end point detection window provided in an opening in the polyurethane sheet. In a dynamic viscoelasticity measurement of the end point detection window performed under the conditions of a tensile mode, a frequency of 1.0 Hz, and 10 to 100°C, the storage elastic modulus E'_W90 at 90°C is 1.0×10⁷ Pa or more, the D hardness (D_W80) of the end point detection window at 80°C is 40 or more, and the D hardness (D_W20) of the end point detection window at 20°C is from 40 to 90.

Description

Method for manufacturing polishing pad and polishing workpiece

The present invention relates to a polishing pad and a method for manufacturing a polished product using the same.

In the semiconductor manufacturing process, chemical mechanical polishing (CMP) is used in the process of flattening after insulating film deposition and forming metal wiring. One of the important techniques required for chemical mechanical polishing is polishing endpoint detection for detecting whether the polishing process has been completed. For example, over-polishing or under-polishing to the target polishing end point directly leads to product defects. Therefore, in chemical mechanical polishing, it is necessary to strictly control the polishing amount by detecting the polishing end point.

Chemical mechanical polishing is a complicated process, and the polishing speed (polishing rate) varies depending on the operating conditions of the polishing equipment, the quality of consumables (slurry, polishing pads, dressers, etc.), and variations in conditions over time during the polishing process. Change. Furthermore, in recent years, the precision and in-plane uniformity of the residual film thickness required in the semiconductor manufacturing process have become more and more severe. Under these circumstances, it is becoming more difficult to detect the polishing end point with sufficient accuracy.

Known major polishing end point detection methods include the optical end point detection method, the torque end point detection method, and the eddy current end point detection method. The end point is detected by irradiating the wafer with light through the member and monitoring the reflected light.

As a polishing pad using such an optical end point detection system, for example, Patent Document 1 discloses a polishing pad that can suppress slurry from accumulating in grooves of a window member and increase the accuracy of polishing rate detection. A polishing pad having a pad body and a transparent window member formed integrally with a part of the pad body, wherein the surface of the window member is recessed from the surface of the pad body. It is disclosed to

JP-A-2002-001647

By the way, as one method for producing a polishing pad having a window as described above, a resin composition is filled and cured in a state where a window member is fixed in a mold, and then the obtained cured product is sliced. and then perform a dressing process. Here, since the window member and the cured product of the resin composition are made of different materials, their physical properties are not a little different. . Also, when performing the dressing process, the window may be recessed due to the difference in the amount of wear between the window and the polishing layer.

When such dents occur, slurry and polishing waste tend to accumulate there, causing scratches and the like, possibly degrading the surface quality of the object to be polished. Further, when the amount of wear of the window portion is smaller than that of the polishing layer, the window portion is more likely to remain than the polishing layer as the polishing progresses, and as a result, the window portion may become convex. Such convex windows may also cause scratches and the like, degrading the surface quality of the object to be polished.

The present invention has been made in view of the above problems, and in the first and third embodiments, a polishing pad having excellent flatness during slicing and dressing processes and a polishing workpiece using the same are provided. One of the objects is to provide a manufacturing method.

In addition, if the polishing layer and the endpoint detection window have different characteristics as in Patent Document 1, for example, the endpoint detection window portion is polished faster than the polishing layer and becomes a dent, and slurry and polishing dust tend to accumulate there. Defects (surface defects) may occur. Furthermore, if the end-point detection window is polished later than the polishing layer, the end-point detection window becomes a convex portion as polishing progresses, causing defects and possibly degrading the surface quality of the object to be polished. .

The present invention has been made in view of the above-mentioned problems, and in the second and fourth embodiments, it is possible to obtain an object to be polished which has an endpoint detection window and is less susceptible to defects and has excellent surface quality. It is an object of the present invention to provide a polishing pad capable of polishing and a method of manufacturing a polishing workpiece using the same.

[First Embodiment]
The present inventors have made extensive studies to solve the above problems. As a result, the inventors have found that the above problems can be solved by providing the endpoint detection window with predetermined viscoelasticity and hardness, and have completed the present invention.

That is, the first embodiment of the present invention is as follows.
[1]
having a polishing layer and an endpoint detection window provided in an opening of the polishing layer;
In the dynamic viscoelasticity measurement of the endpoint detection window performed under the conditions of tensile mode, frequency of 1.0 Hz, and 10 to 100 ° C., the storage elastic modulus E′ _W90 at 90 ° C. is 1.0 × ¹⁰ Pa or more,
The D hardness (D _W80 ) of the endpoint detection window at 80° C. is 40 or more,
The endpoint detection window has a D hardness (D _W20 ) at 20° C. of 40 to 90.
polishing pad.
[2]
wherein the endpoint detection window comprises a polyurethane resin WI;
The polishing pad according to [1].
[3]
The polyurethane resin WI contains structural units derived from an alicyclic isocyanate and/or an aliphatic isocyanate,
The polishing pad according to [2].
[4]
The polyurethane resin WI contains structural units derived from a compound having 3 or more hydroxyl groups,
The polishing pad according to [2] or [3].
[5]
In the dynamic viscoelasticity measurement of the endpoint detection window, the storage elastic modulus E′ _W30 at 30° C. is 60×107 to 100× ¹⁰⁷ Pa.
[1] The polishing pad according to any one of [4].
[6]
In the dynamic viscoelasticity measurement of the endpoint detection window, the peak temperature of tan δ is 70 to 100 ° C.
[1] The polishing pad according to any one of [5].
[7]
The polishing layer contains a polyurethane resin P and hollow fine particles dispersed in the polyurethane resin P.
[1] The polishing pad according to any one of [6].
[8]
a polishing step of polishing an object to be polished using the polishing pad according to any one of [1] to [7] in the presence of a polishing slurry to obtain a polished object;
an endpoint detection step of performing endpoint detection by an optical endpoint detection method during the polishing;
A method for producing an abrasive article.

[Second embodiment]
The present inventors have made extensive studies to solve the above problems. As a result, the inventors have found that the above problems can be solved by establishing a predetermined relationship between the endpoint detection window and the viscoelasticity of the polishing layer, and have completed the present invention.

That is, the second embodiment of the present invention is as follows.
[1]
having a polishing layer and an endpoint detection window provided in an opening of the polishing layer;
In the dynamic viscoelasticity measurement performed under the conditions of tensile mode, frequency 1.0 Hz, 10 to 100 ° C., the storage elastic modulus _E'W30 at 30 ° C. of the end point detection window and the storage elastic modulus E at 30 ° C. of the polishing layer ' _P30 ratio (E' _P30 /E' _W30 ) is 0.60 to 1.50,
polishing pad.
[2]
wherein the endpoint detection window comprises a polyurethane resin WI;
The polishing pad according to [1].
[3]
The polyurethane resin WI contains structural units derived from an alicyclic isocyanate and/or an aliphatic isocyanate,
The polishing pad according to [2].
[4]
The polyurethane resin WI contains structural units derived from a compound having 3 or more hydroxyl groups,
The polishing pad according to [2] or [3].
[5]
In the dynamic viscoelasticity measurement, the ratio of the storage elastic modulus _E'W50 at 50°C of the end point detection window to the storage elastic modulus _E'P50 at 50°C of the polishing layer ( _E'P50 / _E'W50 ) is , between 0.70 and 2.00;
[1] The polishing pad according to any one of [4].
[6]
In the dynamic viscoelasticity measurement of the endpoint detection window, the storage elastic modulus E′ _W30 at 30° C. is 10×10 ⁷ to 60×10 ⁷ Pa.
[1] The polishing pad according to any one of [5].
[7]
The endpoint detection window has a D hardness (D _W20 ) at 20° C. of 40 to 70.
[1] The polishing pad according to any one of [6].
[8]
The polishing layer contains a polyurethane resin P and hollow fine particles dispersed in the polyurethane resin P.
[1] The polishing pad according to any one of [7].
[9]
a polishing step of polishing an object to be polished using the polishing pad according to any one of [1] to [8] in the presence of a polishing slurry;
an endpoint detection step of performing endpoint detection by an optical endpoint detection method during the polishing;
A method for producing an abrasive article.

[Third Embodiment]
The present inventors have made extensive studies to solve the above problems. As a result, the inventors have found that the above problems can be solved by providing a predetermined relationship between the endpoint detection window and the polishing layer in the analysis by pulse NMR, and have completed the present invention.

That is, the third embodiment of the present invention is as follows.
[1]
having a polishing layer and an endpoint detection window provided in an opening of the polishing layer;
The spin-spin relaxation free induction decay curve of 1H obtained by measurement by the Solid Echo method using pulsed NMR is divided into 3 phases derived from the three components of the crystalline phase, intermediate phase, and amorphous phase in order of shortest relaxation time. When the waveform is separated into two curves,
a ratio (Lp20/Lw20) of the abundance ratio Lw20 of the amorphous phase in the endpoint detection window to the abundance ratio Lp20 of the amorphous phase in the polishing layer at 20° C. is 0.5 to 2.0;
The ratio (Sp80/Sw80) of the crystalline phase abundance ratio Sw80 of the endpoint detection window to the crystalline phase abundance ratio Sp80 of the polishing layer at 80° C. is 0.5 to 2.0.
polishing pad.
[2]
The ratio (Mp20/Mw20) of the abundance ratio Mw20 of the intermediate phase in the endpoint detection window to the abundance ratio Mp20 of the intermediate phase in the polishing layer at 20° C. is 0.7 to 1.5.
The polishing pad according to [1].
[3]
The ratio (Mp80/Mw80) of the abundance ratio Mw80 of the intermediate phase in the endpoint detection window to the abundance ratio Mp80 of the intermediate phase in the polishing layer at 80° C. is 0.5 to 1.5.
The polishing pad according to [1] or [2].
[4]
The difference (|Lp20−Lw20|) between the abundance ratio Lw20 and the abundance ratio Lp20 is 10 or less.
[1] The polishing pad according to any one of [3].
[5]
The difference (|Sp80−Sw80|) between the abundance ratio Sw80 and the abundance ratio Sw80 is 15 or less.
[1] The polishing pad according to any one of [4].
[6]
wherein the endpoint detection window comprises a polyurethane resin WI;
The polyurethane resin WI contains a structural unit derived from an aliphatic isocyanate,
[1] The polishing pad according to any one of [5].
[7]
The polishing layer contains a polyurethane resin P,
The polyurethane resin P contains a structural unit derived from an aromatic isocyanate,
[1] The polishing pad according to any one of [6].
[8]
The polishing layer contains hollow fine particles dispersed in the polishing layer,
[1] The polishing pad according to any one of [7].
[9]
a polishing step of polishing an object to be polished using the polishing pad according to any one of [1] to [8] in the presence of a polishing slurry to obtain a polished object;
an endpoint detection step of performing endpoint detection by an optical endpoint detection method during the polishing;
A method for producing an abrasive article.

[Fourth Embodiment]
The present inventors have made extensive studies to solve the above problems. As a result, the inventors have found that the above problems can be solved by establishing a predetermined relationship between the endpoint detection window and the viscoelasticity of the polishing layer, and have completed the present invention.

That is, the fourth embodiment of the present invention is as follows.
[1]
having a polishing layer and an endpoint detection window provided in an opening of the polishing layer;
In the dynamic viscoelasticity measurement performed under the conditions of tensile mode, frequency of 1.6 Hz, 30 to 55°C, and immersion, the storage elastic modulus E′w40 of the endpoint detection window at 40°C and the polishing layer at 40°C The ratio (E'p40/E'w40) to the storage modulus E'p40 is 0.70 to 3.00.
polishing pad.
[2]
In the dynamic viscoelasticity measurement, the ratio (E'p50/E'w50) of the storage elastic modulus E'w50 of the endpoint detection window at 50°C and the storage elastic modulus E'p50 of the polishing layer at 50°C is , from 0.70 to 5.00;
The polishing pad according to [1].
[3]
In the dynamic viscoelasticity measurement, the difference between the loss coefficient tan δw30 of the endpoint detection window at 30° C. and the loss coefficient tan δp30 of the polishing layer at 30° C. (|tan δw30−tan δp30|) is 0.05 to 0.30. is
The polishing pad according to [1] or [2].
[4]
In the dynamic viscoelasticity measurement, the difference between the loss coefficient tan δw40 of the endpoint detection window at 40° C. and the loss coefficient tan δp40 of the polishing layer at 40° C. (|tan δw40−tan δp40|) is 0.05 to 0.40. is
[1] The polishing pad according to any one of [3].
[5]
In the dynamic viscoelasticity measurement, the difference between the loss coefficient tan δw50 of the endpoint detection window at 50° C. and the loss coefficient tan δp50 of the polishing layer at 50° C. (|tan δw50−tan δp50|) is 0.05 to 0.50. is
[1] The polishing pad according to any one of [4].
[6]
wherein the endpoint detection window comprises a polyurethane resin WI;
The polyurethane resin WI contains a structural unit derived from an aliphatic isocyanate,
[1] The polishing pad according to any one of [5].
[7]
The polishing layer contains a polyurethane resin P,
The polyurethane resin P contains a structural unit derived from an aromatic isocyanate,
[1] The polishing pad according to any one of [6].
[8]
The polishing layer contains hollow fine particles dispersed in the polishing layer,
[1] The polishing pad according to any one of [7].
[9]
a polishing step of polishing an object to be polished using the polishing pad according to any one of [1] to [8] in the presence of a polishing slurry to obtain a polished object;
an endpoint detection step of performing endpoint detection by an optical endpoint detection method during the polishing;
A method for producing an abrasive article.

According to the first and third embodiments of the present invention, it is possible to provide a polishing pad with excellent flatness during slicing and dressing, and a method for manufacturing a polished product using the same.

Further, according to the second embodiment and the fourth embodiment of the present invention, there is provided a polishing pad capable of obtaining an object to be polished having excellent surface quality while having an end-point detection window, while being resistant to defects. A method for manufacturing an abrasive article can be provided.

1 is a schematic perspective view of polishing pads of first to fourth embodiments; FIG. FIG. 4 is a schematic cross-sectional view of the end point detection window portion of the polishing pad of the first to fourth embodiments; FIG. 5 is a schematic cross-sectional view of another aspect of the end point detection window portion of the polishing pad of the first to fourth embodiments; 1 is a schematic diagram showing a film thickness control system installed in CMP; FIG. FIG. 10 is a diagram showing the surface state of the end point detection window portion of the polishing pad of Example A1 after slicing and before dressing; FIG. 10 is a diagram showing the surface state of the end point detection window portion of the polishing pad of Comparative Example A1 after slicing and before dressing. FIG. 10 is a diagram showing the surface state of the end point detection window portion of the polishing pad of Comparative Example A2 after slicing and before dressing. FIG. 10 is a diagram showing the surface state of the endpoint detection window portion of the polishing pad of Example A2 after slicing and before dressing; FIG. 10 is a diagram showing the surface state of the end point detection window portion of the polishing pad of Example A1 after dressing. FIG. 10 is a diagram showing the surface state of the end point detection window portion of the polishing pad of Comparative Example A1 after dressing. FIG. 10 is a diagram showing the surface state of the end point detection window portion of the polishing pad of Comparative Example A2 after dressing. FIG. 10 is a diagram showing the surface state of the endpoint detection window portion of the polishing pad of Example A2 after dressing. FIG. 10 is a diagram showing the surface state of the endpoint detection window portion of the polishing pad of Example C1 after slicing and before dressing. FIG. 10 is a diagram showing the surface state of the endpoint detection window portion of the polishing pad of Example C2 after slicing and before dressing; FIG. 10 is a diagram showing the surface state of the end point detection window portion of the polishing pad of Comparative Example C1 after slicing and before dressing. FIG. 10 is a diagram showing the surface state of the end point detection window portion of the polishing pad of Example C1 after dressing. FIG. 10 is a diagram showing the surface state of the endpoint detection window portion of the polishing pad of Example C2 after dressing. FIG. 10 is a diagram showing the surface state of the end point detection window portion of the polishing pad of Comparative Example C1 after dressing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as necessary, but the present invention is not limited to these, and various modifications can be made without departing from the scope of the invention. be. In the drawings, the same elements are denoted by the same reference numerals, and overlapping descriptions are omitted. Moreover, the positional relationship such as up, down, left and right is based on the positional relationship shown in the drawings unless otherwise specified. Furthermore, the dimensional ratios of the drawings are not limited to the illustrated ratios.

1. First Embodiment 1.1. Polishing Pad The polishing pad of the first embodiment has a polishing layer and an end point detection window provided in the opening of the polishing layer, and the end point is performed under the conditions of tensile mode, frequency of 1.0 Hz, and 10 to 100°C. In the dynamic viscoelasticity measurement of the detection window, the storage elastic modulus E′ _W90 at 90° C. is 1.0×10 ⁷ Pa or more, and the D hardness (D _W80 ) of the endpoint detection window at 80° C. is 40 or more. and the D hardness (D _W20 ) at 20° C. of the endpoint detection window is 40-70.

As a result, the flatness can be improved from the viewpoint that convex portions are less likely to occur in the slicing process, and the flatness can be improved from the viewpoint that the end point detection window is less likely to be over-polished than the polishing layer during the dressing process. can be done. In the first embodiment, these two types of flatness are simply referred to as "flatness".

FIG. 1 shows a schematic perspective view of the polishing pad of the first embodiment. As shown in FIG. 1, the polishing pad 10 of the first embodiment has a polishing layer 11 and an end point detection window 12, and optionally a cushion layer 13 on the side opposite to the polishing surface 11a. may have.

2 and 3 show cross-sectional views around the endpoint detection window 12 in FIG. As shown in FIGS. 2 and 3, an adhesive layer 14 may be provided between the polishing layer 11 and the cushion layer 13, and the surface of the cushion layer 13 is attached to the table 22 shown in FIG. An adhesive layer 15 may be provided for the purpose. The polishing surface 11a of the polishing pad of the first embodiment may be flat as shown in FIG. 2, or may be uneven with grooves 16 formed therein as shown in FIG. The grooves 16 may be formed with a plurality of grooves having various shapes such as concentric circles, grids, and radial grooves singly or in combination.

1.1.1. End Point Detection Window The end point detection window is a transparent member provided in the opening of the polishing layer, and serves as a transmission path for light from the film thickness detection sensor in optical end point detection. Although the endpoint detection window is circular in the first embodiment, it may be square, rectangular, polygonal, elliptical, or the like, if necessary.

In the first embodiment, in the process of manufacturing the polishing pad, when slicing, the endpoint detection window becomes recessed from the polishing layer or cracks, and when the dressing process is performed, The storage elastic modulus E' and D hardness of the endpoint detection window are defined from the viewpoint of suppressing the endpoint detection window from becoming recessed or protruding from the polishing layer and improving flatness.

1.1.1.1. Dynamic Viscoelasticity The storage elastic modulus E′ of the endpoint detection window in the first embodiment can be obtained by dynamic viscoelasticity measurement performed under the conditions of tensile mode, frequency of 1.0 Hz, and 10 to 100°C. As will be described later, slicing is performed while the object is heated, so the storage elastic modulus E′ _W90 at 90° C. is defined as the storage elastic modulus E′ of the endpoint detection window in the first embodiment. In the first embodiment, the peak of the loss tangent tan δ is set so that the loss elastic modulus E″ (viscous component) is more dominant than the storage elastic modulus E′ (elastic component) during slicing. The temperature position may be further adjusted, and the storage elastic modulus _E′W30 at 30° C. may be specified from the viewpoint of expressing the characteristics of the endpoint detection window during dressing.

The storage elastic modulus E′ _W90 of the endpoint detection window at 90° C. is 1.0×10 ⁷ Pa or more, preferably 1.25×10 ⁷ to 20×10 ⁷ Pa, more preferably 1.5×10 7 Pa or more. It is 10 ⁷ to 10×10 ⁷ Pa. The storage elastic modulus E′ _W90 of 1.0×10 ⁷ Pa or more prevents the end-point detection window from becoming recessed or protruding from the polishing layer, or from cracking when slicing. can be suppressed, and flatness can be further improved.

In addition, in the dynamic viscoelasticity measurement in the endpoint detection window, the peak temperature of tan δ is preferably 70-100°C, more preferably 70-95, still more preferably 75-90. When the peak temperature of tan δ is within the above range, when slicing, it is possible to suppress the end-point detection window from becoming recessed or protruding from the polishing layer, or from being cracked, thereby improving flatness. can be improved.

Furthermore, the storage elastic modulus E′ _W30 at 30° C. is preferably 10×10 ⁷ to 80×10 ⁷ Pa, more preferably 20×10 ⁷ to 70×10 ⁷ Pa, still more preferably 30×10 ⁷ to 70×10 ⁷ Pa. When the storage elastic modulus _E′W30 is within the above range, it is possible to suppress the end-point detection window from being recessed from the polishing layer when performing the dressing process, and to improve the flatness. can be improved.

Although the measurement conditions for dynamic viscoelasticity measurement are not particularly limited, the measurement can be performed under the conditions described in Examples.

1.1.1.2. D Hardness The D hardness (D _W80 ) of the endpoint detection window at 80° C. is 40 or more, preferably 40-60, more preferably 40-50. When the D hardness (D _W80 ) is 40 or more, when slicing, it is possible to suppress the end point detection window from being recessed or protruding from the polishing layer, or from being cracked, thereby improving flatness. can be improved.

The D hardness (D _W20 ) of the endpoint detection window at 20° C. is 40-90, preferably 50-85, more preferably 55-80. When the D hardness (D _W20 ) is within the above range, it is possible to suppress the end-point detection window from becoming recessed or protruding from the polishing layer when the dressing process is performed. Flatness can be further improved.

The conditions for measuring the D hardness are not particularly limited, but can be measured according to the conditions described in the examples.

1.1.1.3. Constituent Material The material constituting the endpoint detection window is not particularly limited as long as it is a transparent member that can function as a window. Examples include polyurethane resin WI, polyvinyl chloride resin, polyvinylidene fluoride resin, polyethersulfone resin, polystyrene resin, polyethylene resin, polytetrafluoroethylene resin, and the like. Among these, polyurethane resin WI is preferable. By using such a resin, the dynamic viscoelastic properties, D hardness, and transparency can be more easily adjusted, and the flatness can be further improved.

The polyurethane resin WI can be synthesized from polyisocyanate and polyol, and contains structural units derived from polyisocyanate and structural units derived from polyol.

1.1.1.3.1. Structural Units Derived from Polyisocyanates Structural units derived from polyisocyanates are not particularly limited, but for example, structural units derived from alicyclic isocyanates, structural units derived from aliphatic isocyanates, and structures derived from aromatic isocyanates units. Among these, the polyurethane resin WI preferably contains structural units derived from an alicyclic isocyanate and/or an aliphatic isocyanate. This makes it easier to adjust the dynamic viscoelastic properties, D hardness (D _W20 ), and D hardness (D _W80 ) within the above ranges, further improving the transparency and further improving the yellowing resistance of the window. It is in. Moreover, the flatness can be further improved.

The alicyclic isocyanate is not particularly limited, but examples include 4,4′-methylene-bis(cyclohexyl isocyanate) (hydrogenated MDI), cyclohexylene-1,2-diisocyanate, cyclohexylene-1,4-diisocyanate, and isophorone diisocyanate.

Examples of aliphatic isocyanates include, but are not limited to, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), tetramethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, and trimethylene diisocyanate. , trimethylhexamethylene diisocyanate, and the like.

Examples of aromatic isocyanates include, but are not limited to, phenylene diisocyanate, 2,6-tolylene diisocyanate (2,6-TDI), 2,4-tolylene diisocyanate (2,4-TDI), xylylene diisocyanate, naphthalene diisocyanate and diphenylmethane-4,4'-diisocyanate (MDI).

1.1.1.3.2. Structural Units Derived from Polyols Structural units derived from polyols are not particularly limited.

Examples of low-molecular-weight polyols include, but are not limited to, ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,2-butylene glycol, 1,3-butylene glycol, 2,3-butylene glycol, 1,4- butylene glycol, 1,5-pentanediol, neopentyl glycol, 1,6-hexane glycol, 2,5-hexanediol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, tricyclode low-molecular-weight polyols having two hydroxyl groups such as candimethanol and 1,4-cyclohexanedimethanol; and low-molecular-weight polyols having three or more hydroxyl groups such as glycerin, hexanetriol, trimethylolpropane, isocyanuric acid and erythritol. Low-molecular-weight polyols may be used singly or in combination of two or more.

Among these, low-molecular-weight polyols having 3 or more hydroxyl groups are preferred, and glycerin is more preferred. By using such a low-molecular-weight polyol, the dynamic viscoelastic properties and D hardness can be easily adjusted within the above range, the wear amount can be adjusted, the flatness can be further improved, and the transparency can be further improved. In addition, the yellowing resistance of windows tends to be further improved.

The content of the structural unit derived from the low-molecular-weight polyol having 3 or more hydroxyl groups is preferably 8.0 to 30 parts, more preferably 10 to 25 parts, per 100 parts of the structural unit derived from the polyisocyanate. and more preferably 12.5 to 20 parts. When the content of the structural unit derived from the low-molecular-weight polyol having three or more hydroxyl groups is within the above range, the dynamic viscoelastic properties and D hardness can be easily adjusted within the above range, and the flatness can be further improved. , the transparency tends to be further improved, and the yellowing resistance of the window tends to be further improved.

In addition, the polymer polyol is not particularly limited, but for example, polyether polyol, polyester polyol, polycarbonate polyol, polyether polycarbonate polyol, polyurethane polyol, epoxy polyol, vegetable oil polyol, polyolefin polyol, acrylic polyol, and vinyl monomer-modified polyols. Polymer polyols may be used singly or in combination of two or more.

The number average molecular weight of the polymer polyol is preferably 300-1200, more preferably 400-950, still more preferably 500-800. By using such a polymer polyol, it tends to be easy to adjust the dynamic viscoelastic properties and the D hardness within the above ranges.

Among these, polyether polyol is preferred, and polytetramethylene ether glycol is more preferred. By using such a polymer polyol, the dynamic viscoelastic properties and D hardness can be easily adjusted within the above ranges, the hardness at low temperatures can be easily adjusted, and the decrease in hardness due to temperature rise can be suppressed. . Further, the flatness can be further improved, the transparency is further improved, and the yellowing resistance of the window tends to be further improved.

The content of structural units derived from polyether polyol is preferably 40 to 100 parts, preferably 50 to 90 parts, more preferably 60 to 84 parts, per 100 parts of structural units derived from polyisocyanate. Department. When the content of the structural unit derived from the polyether polyol is within the above range, the dynamic viscoelastic properties and D hardness can be easily adjusted within the above range, the flatness can be further improved, and the transparency can be improved. In addition to further improvement, there is a tendency for the yellowing resistance of the window to be further improved.

In addition, as the polyol, it is preferable to use a low-molecular-weight polyol and a high-molecular-weight polyol together, and it is more preferable to use a low-molecular-weight polyol having three or more hydroxyl groups and a polyether polyol together. As a result, the dynamic viscoelastic properties and D hardness can be easily adjusted within the above ranges, the hardness at low temperatures can be easily adjusted, and a decrease in hardness due to temperature rise can be suppressed. Further, the flatness can be further improved, the transparency is further improved, and the yellowing resistance of the window tends to be further improved.

From the above viewpoint, the content of the polyether polyol is preferably 1.0 to 9.0 parts, more preferably 2.0 to 8.0 parts, per 1 part of the low-molecular-weight polyol having 3 or more hydroxyl groups. parts, more preferably 3.0 to 7.0 parts.

1.1.2. Polishing Layer The polishing layer of the first embodiment has an opening in which the endpoint detection window is embedded. Although the position of the opening is not particularly limited, it is preferably provided at a position in the radial direction corresponding to the film thickness detection sensor 23 installed on the table 22 . Although the number of openings is not particularly limited, the openings are arranged at similar radial positions so that the windows pass over the film thickness detection sensor 23 multiple times when the polishing pad 10 attached to the table 22 rotates once. It is preferable to have a plurality of them.

The form of the abrasive layer is not particularly limited, but examples include resin foam molded articles, non-foam molded articles, and resin-impregnated substrates obtained by impregnating fiber substrates with resin.

Here, the resin foam molding refers to a foam that does not have a fiber base material and is composed of a predetermined resin. The foam shape is not particularly limited, but examples thereof include spherical cells, substantially spherical cells, tear-shaped cells, and open cells in which each cell is partially connected.

In addition, a non-foamed resin molded body refers to a non-foamed body that does not have a fiber base material and is composed of a predetermined resin. A non-foamed body refers to a body that does not have air bubbles as described above. In the first embodiment, non-foamed molded articles of resin include those obtained by applying a curable composition to a base material such as a film and then curing the same. More specifically, the resin cured product formed by a labia coater method, a small diameter gravure coater method, a reverse roll coater method, a transfer roll coater method, a kiss coater method, a die coater method, a screen printing method, a spray coating method, etc. Included in non-foamed molded products.

Furthermore, a resin-impregnated base material refers to a material obtained by impregnating a fiber base material with a resin. Here, the fiber 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 depends on the polishing rate and the surface quality of the object to be polished, and in the polishing pad obtained by slicing or dressing, the end point detection window becomes more recessed than the polishing layer or cracks. From the viewpoint of suppressing this, it is preferable to have predetermined dynamic viscoelastic properties.

Specifically, in the dynamic viscoelasticity measurement performed under the conditions of tension mode, frequency of 1.0 Hz, and temperature of 10 to 100°C, the storage elastic modulus E' _P90 of the polishing layer at 90°C is preferably 1.0 × 10 ⁷ . Pa or more, preferably 2.0×10 ⁷ Pa to 20×10 ⁷ Pa, more preferably 3.0×10 ⁷ Pa to 15×10 ⁷ Pa. When the storage elastic modulus E′ _P90 is 1.0×10 ⁷ Pa or more, in addition to improving the polishing rate and the surface quality of the object to be polished, the polishing pad obtained by slicing or dressing has an endpoint detection window. It tends to be more inhibited from becoming recessed or protruding from the polishing layer, or from being cracked, thereby further improving the flatness.

From the same point of view, the difference (E' _P90 -E' _W90 ) between the storage elastic modulus E' _W90 and the storage elastic modulus E' _P90 is 9.5×10 ⁷ Pa or less, preferably 1.0. ×10 ⁷ Pa to 9.0×10 ⁷ Pa, more preferably 2.0×10 ⁷ Pa to 9.0×10 ⁷ Pa. When the difference (E' _P90 -E' _W90 ) is 9.5×10 ⁷ Pa or less, the difference in physical properties between the polishing layer and the endpoint detection window is reduced under the slicing conditions, so that the polishing layer and the endpoint detection window are uniform. , and the shape of the window tends to be flat. Therefore, in the polishing pad obtained by slicing or dressing, the end-point detection window is further suppressed from becoming recessed or protruding from the polishing layer, or from being cracked, thereby further improving flatness. tend to be able.

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 the polyurethane sheet, and any resin sheet can be used.

The polyurethane resin P constituting the polyurethane sheet is not particularly limited, but examples thereof include polyester-based polyurethane resins, polyether-based polyurethane resins, and polycarbonate-based polyurethane resins. You may use these individually by 1 type or in combination of 2 or more types.

Such a polyurethane resin P can be synthesized from a polyisocyanate and a polyol, and a reaction product of a urethane prepolymer and a curing agent is particularly preferred. Here, the urethane prepolymer can be synthesized from polyisocyanate and polyol. The polyisocyanate, polyol, and curing agent that constitute the polyurethane resin P are described below.

1.1.2.2.1. Structural Units Derived from Polyisocyanates Structural units derived from polyisocyanates are not particularly limited, but for example, structural units derived from alicyclic isocyanates, structural units derived from aliphatic isocyanates, and structures derived from aromatic isocyanates units. Among these, aromatic isocyanates are preferred, and 2,4-tolylene diisocyanate (2,4-TDI) is more preferred.

As the alicyclic isocyanate, aliphatic isocyanate, and aromatic isocyanate, the same ones as those exemplified in the endpoint detection window can be exemplified.

1.1.2.2.2. Structural Units Derived from Polyols Structural units derived from polyols are not particularly limited. Among these, it is preferable to use at least a low-molecular-weight polyol, and it is preferable to use a combination of a low-molecular-weight polyol and a high-molecular-weight polyol.

Examples of low-molecular-weight polyols and high-molecular-weight polyols are the same as those exemplified in the endpoint detection window. Among these, as the low-molecular-weight polyol, a low-molecular-weight polyol having two hydroxyl groups is preferable, and diethylene glycol is more preferable. Moreover, as a 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, but examples thereof include polyamines and polyols. Curing agents may be used singly or in combination of two or more.

Examples of polyamines include, but are not limited to, aliphatic polyamines such as ethylenediamine, propylenediamine and hexamethylenediamine; alicyclic polyamines such as isophoronediamine and dicyclohexylmethane-4,4'-diamine; Dichloro-4,4'-diaminodiphenylmethane (MOCA), 4-methyl-2,6-bis(methylthio)-1,3-benzenediamine, 2-methyl-4,6-bis(methylthio)-1,3- aromatic polyamines such as benzenediamine and 2,2-bis(3-amino-4-hydroxyphenyl)propane;

Among these, aromatic polyamines are preferred, and 3'-dichloro-4,4'-diaminodiphenylmethane (MOCA) is more preferred.

As the polyol, the same polyols as those exemplified in the endpoint detection window can be exemplified. Among these, polymer polyols are preferred, polyether polyols are more preferred, and polypropylene glycol is even more preferred.

1.1.2.2.4. Hollow Fine Particles 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 a polyurethane sheet has closed cells derived from hollow fine particles, and tends to easily adjust the dynamic viscoelasticity and D hardness within the above ranges.

Commercially available hollow microparticles may be used, or those obtained by synthesizing by a conventional method may be used. The shell material of the hollow fine particles is not particularly limited, but examples include polyvinyl alcohol, polyvinylpyrrolidone, poly(meth)acrylic acid, polyacrylamide, polyethylene glycol, polyhydroxyether acrylate, maleic acid copolymer, and 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 spherical or substantially spherical, for example. Further, when the hollow fine particles are expandable balloons, they may be used in an unexpanded state or in an expanded state.

The average particle size of the hollow fine particles contained in the polyurethane sheet is preferably 5-200 μm, more preferably 5-80 μm, still more preferably 5-50 μm, and particularly preferably 5-35 μm. When the average particle size is within the above range, it tends to be easy to adjust the dynamic viscoelastic properties and D hardness within the above range. The average particle diameter can be measured by a laser diffraction particle size distribution analyzer (eg, Mastersizer-2000 manufactured by Spectris Co., Ltd.) or the like.

1.1.3. Others The polishing pad of the first embodiment may have a cushion layer on the side opposite to the polishing surface of the polishing layer. The surface to be attached to the polishing machine) may have an adhesive layer. In this case, the cushion layer and the adhesive layer have openings at locations similar to where the endpoint detection windows of the polishing layer are located.

2. Second Embodiment 2.1. Polishing Pad The polishing pad of the second embodiment has a polishing layer and an end point detection window provided in the opening of the polishing layer, and is operated under the conditions of tensile mode, frequency of 1.0 Hz, and 10 to 100°C. In the physical viscoelasticity measurement, the ratio of the storage elastic modulus _E'W30 at 30°C of the endpoint detection window to the storage elastic modulus _E'P30 of the polishing layer at 30°C ( _E'P30 / _E'W30 ) is 0. 0.60 to 1.50.

As a result, during polishing, the dynamic viscoelastic properties of the polishing layer and the endpoint detection window are more similar, so even when the endpoint detection window, which is a different member, is embedded in the polishing layer, the The occurrence of defects (surface defects) is further suppressed. Therefore, an object to be polished having excellent surface quality can be obtained.

FIG. 1 shows a schematic perspective view of the polishing pad of the second embodiment. As shown in FIG. 1, the polishing pad 10 of the second embodiment has a polishing layer 11 and an end point detection window 12, and optionally a cushion layer 13 on the side opposite to the polishing surface 11a. may have.

2 and 3 show cross-sectional views around the endpoint detection window 12 in FIG. As shown in FIGS. 2 and 3, an adhesive layer 14 may be provided between the polishing layer 11 and the cushion layer 13, and the surface of the cushion layer 13 is attached to the table 22 shown in FIG. An adhesive layer 15 may be provided for the purpose. The polishing surface 11a of the polishing pad of the second embodiment may be flat as shown in FIG. 2, or may be uneven with grooves 16 formed therein as shown in FIG. The grooves 16 may be formed with a plurality of grooves having various shapes such as concentric circles, grids, and radial grooves singly or in combination.

2.1.1. End Point Detection Window The end point detection window is a transparent member provided in the opening of the polishing layer, and serves as a transmission path for light from the film thickness detection sensor in optical end point detection. Although the endpoint detection window is circular in the second embodiment, it may be square, rectangular, polygonal, elliptical, or the like, if desired.

In the second embodiment, the degree of abrasion of the endpoint detection window and the polishing layer during polishing is adjusted, and either the endpoint detection window or the polishing layer is excessively polished, thereby causing defects (surface defects) on the non-polished object. From the viewpoint of suppressing the occurrence of , the ratio of the storage elastic modulus E′ between the end point detection window and the polishing layer is defined.

2.1.1.1. Dynamic Viscoelasticity The end-point detection window and the storage elastic modulus E′ of the polishing layer in the second embodiment can be determined by dynamic viscoelasticity measurement performed under the conditions of tensile mode, frequency of 1.0 Hz, and 10 to 100°C. In the second embodiment, the ratio of the storage elastic modulus E' at 30° C. is specified from the viewpoint of representing the properties of the endpoint detection window and the polishing layer during polishing.

The ratio of the storage elastic modulus _E'W30 at 30°C of the endpoint detection window to the storage elastic modulus _E'P30 of the polishing layer at 30°C ( _E'P30 / _E'W30 ) is 0.60 to 1.50. , preferably 0.60 to 1.35, more preferably 0.60 to 1.20. When the ratio (E' _P30 /E' _W30 ) is within the above range, the properties of the endpoint detection window and the polishing layer are similar during polishing, so that the surface quality of the resulting polished object is further improved.

From the same point of view, in the dynamic viscoelasticity measurement, the ratio of the storage elastic modulus _E'W50 at 50°C of the endpoint detection window to the storage elastic modulus _E'P50 of the polishing layer at 50°C ( _E'P50 /E ' _W50 ) is preferably 0.70 to 2.00, more preferably 0.70 to 1.85, and still more preferably 0.70 to 1.70. When the ratio (E' _P50 /E' _W50 ) is within the above range, the properties of the end point detection window and the polishing layer during polishing are similar, so the surface quality of the resulting polished object tends to be further improved. .

In the dynamic viscoelasticity measurement in the endpoint detection window, the storage modulus _E′W30 at 30° C. is preferably 10×10 ⁷ to 60×10 ⁷ Pa, more preferably 15×10 ⁷ to 55×10 ⁷ Pa. and more preferably 20×10 ⁷ to 50×10 ⁷ Pa. When the storage elastic modulus _E'W30 is within the above range, the surface quality of the object to be polished tends to be further improved.

2.1.1.2. D Hardness The D hardness (D _W20 ) of the endpoint detection window at 20° C. is 40-70, preferably 45-70, more preferably 50-65. When the D hardness (D _W20 ) is within the above range, the occurrence of defects (surface defects) tends to be more suppressed.

2.1.1.3. Constituent Material The material constituting the endpoint detection window is not particularly limited as long as it is a transparent member that can function as a window. Examples include polyurethane resin WI, polyvinyl chloride resin, polyvinylidene fluoride resin, polyethersulfone resin, polystyrene resin, polyethylene resin, polytetrafluoroethylene resin, and the like. Among these, polyurethane resin WI is preferable. By using such a resin, it is easier to adjust the dynamic viscoelastic properties, D hardness, and transparency.

2.1.1.3.1. Structural Units Derived from Polyisocyanates Structural units derived from polyisocyanates are not particularly limited, but for example, structural units derived from alicyclic isocyanates, structural units derived from aliphatic isocyanates, and structures derived from aromatic isocyanates units. Among these, the polyurethane resin WI preferably contains structural units derived from an alicyclic isocyanate and/or an aliphatic isocyanate. As a result, the dynamic viscoelastic properties and the D hardness can be easily adjusted within the above range, the transparency is further improved, and the yellowing resistance of the window tends to be further improved.

The alicyclic isocyanate, aliphatic isocyanate, and aromatic isocyanate are not particularly limited, but include, for example, the compounds exemplified in the first embodiment.

2.1.1.3.2. Structural Units Derived from Polyols Structural units derived from polyols are not particularly limited.

The low-molecular-weight polyol is not particularly limited, but includes, for example, the compounds exemplified in the first embodiment.

Among these, low-molecular-weight polyols having 3 or more hydroxyl groups are preferred, and glycerin is more preferred. By using such a low-molecular-weight polyol, the dynamic viscoelastic properties and D hardness can be easily adjusted within the above range, the amount of wear can be adjusted, the transparency is further improved, and the yellowing resistance of the window is further improved. tend to

The content of the structural unit derived from the low-molecular-weight polyol having 3 or more hydroxyl groups is preferably 7.5 to 30 parts, more preferably 10 to 25 parts, per 100 parts of the structural unit derived from the polyisocyanate. and more preferably 12.5 to 20 parts. When the content of the structural unit derived from the low-molecular-weight polyol having three or more hydroxyl groups is within the above range, the dynamic viscoelastic properties and D hardness are easily adjusted within the above range, and the transparency is further improved. , the yellowing resistance of windows tends to be more improved.

In addition, the polymer polyol is not particularly limited, but includes, for example, the compounds exemplified in the first embodiment.

The number average molecular weight of the polymer polyol is preferably 300-3000, more preferably 500-2500, still more preferably 850-2000. By using such a polymer polyol, it tends to be easy to adjust the dynamic viscoelastic properties and the D hardness within the above ranges.

Among these, polyether polyol is preferred, and poly(oxytetramethylene) glycol is more preferred. By using such a polymer polyol, the dynamic viscoelastic properties and D hardness can be easily adjusted within the above ranges, the hardness at low temperatures can be easily adjusted, and the decrease in hardness due to temperature rise can be suppressed. . In addition, the transparency tends to be further improved, and the yellowing resistance of windows tends to be further improved.

The content of structural units derived from polyether polyol is preferably 80 to 200 parts, more preferably 85 to 160 parts, and still more preferably 90 to 100 parts based on 100 parts of structural units derived from polyisocyanate. 140 copies. When the content of the structural unit derived from the polyether polyol is within the above range, the dynamic viscoelastic properties and D hardness are easily adjusted within the above range, the transparency is further improved, and the yellowing resistance of the window is improved. tend to improve.

In addition, as the polyol, it is preferable to use a low-molecular-weight polyol and a high-molecular-weight polyol together, and it is more preferable to use a low-molecular-weight polyol having three or more hydroxyl groups and a polyether polyol together. As a result, the dynamic viscoelastic properties and the D hardness can be easily adjusted within the above range, the transparency is further improved, and the yellowing resistance of the window tends to be further improved.

From the above viewpoint, the content of the polyether polyol is preferably 2.0 to 15.0 parts, more preferably 3.0 to 12.5 parts, relative to 1 part of the low-molecular-weight polyol having 3 or more hydroxyl groups. parts, more preferably 4.0 to 9.0 parts.

2.1.2. Polishing Layer The polishing layer of the second embodiment has an opening in which the endpoint detection window is embedded. Although the position of the opening is not particularly limited, it is preferably provided at a position in the radial direction corresponding to the film thickness detection sensor 23 installed on the table 22 . Although the number of openings is not particularly limited, the openings are arranged at similar radial positions so that the windows pass over the film thickness detection sensor 23 multiple times when the polishing pad 10 attached to the table 22 rotates once. It is preferable to have a plurality of them.

Here, descriptions of the foamed resin article, the non-foamed molded article, the resin-impregnated base material, and the fiber base material are omitted because they are the same as those described in the first embodiment.

2.1.2.1. Dynamic Viscoelasticity In the dynamic viscoelasticity measurement of the polishing layer, the storage elastic modulus E′ _P30 at 30° C. is preferably 15×10 ⁷ to 65×10 ⁷ Pa, more preferably 20×10 ⁷ to 60×. 10 ⁷ Pa, more preferably 25×10 ⁷ to 55×10 ⁷ Pa. When the storage elastic modulus _E'P30 is 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′ _P50 at 50° C. is preferably 10×10 ⁷ to 40×10 ⁷ Pa, more preferably 15×10 ⁷ to 35×10 ⁷ Pa. and more preferably 20×10 ⁷ to 30×10 ⁷ Pa. When the storage elastic modulus E′ _P50 is 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 description of the polyurethane sheet is omitted because it includes the aspects described in the first embodiment.

2.1.3. Others The polishing pad of the second embodiment may have a cushion layer on the side opposite to the polishing surface of the polishing layer, between the polishing layer and the cushion layer, or on the surface of the cushion layer that is not on the polishing layer side ( The surface to be attached to the polishing machine) may have an adhesive layer. In this case, the cushion layer and the adhesive layer have openings at locations similar to where the endpoint detection windows of the polishing layer are located.

3. Third Embodiment 3.1. Polishing Pad The polishing pad of the third embodiment has a polishing layer and an end-point detection window provided in the opening of the polishing layer, and has a 1H value obtained by measurement by a Solid Echo method using pulse NMR. When the spin-spin relaxation free induction decay curve is separated into three curves derived from the three components of the crystalline phase, the intermediate phase, and the amorphous phase in order of shorter relaxation time, the endpoint detection window at 20 ° C. A ratio (Lp20/Lw20) of the abundance ratio Lw20 of the amorphous phase to the abundance ratio Lp20 of the amorphous phase in the polishing layer is 0.5 to 2.0, and the crystalline phase of the endpoint detection window at 80°C and the abundance ratio Sp80 of the crystalline phase of the polishing layer (Sp80/Sw80) is 0.5 to 2.0.

As a result, the flatness can be improved from the viewpoint that convex portions are less likely to occur in the slicing process, and the flatness can be improved from the viewpoint that the end point detection window is less likely to be over-polished than the polishing layer during the dressing process. can be done. In the third embodiment, these two types of flatness are simply referred to as "flatness".

FIG. 1 shows a schematic perspective view of the polishing pad of the third embodiment. As shown in FIG. 1, the polishing pad 10 of the third embodiment has a polishing layer 11 and an end point detection window 12, and optionally a cushion layer 13 on the side opposite to the polishing surface 11a. may have.

2 and 3 show cross-sectional views around the endpoint detection window 12 in FIG. As shown in FIGS. 2 and 3, an adhesive layer 14 may be provided between the polishing layer 11 and the cushion layer 13, and the surface of the cushion layer 13 is attached to the table 22 shown in FIG. An adhesive layer 15 may be provided for the purpose. The polishing surface 11a of the polishing pad of the third embodiment may be flat as shown in FIG. 2, or may be uneven with grooves 16 formed therein as shown in FIG. The grooves 16 may be formed with a plurality of grooves having various shapes such as concentric circles, grids, and radial grooves singly or in combination.

3.1.1. End Point Detection Window The end point detection window is a transparent member provided in the opening of the polishing layer, and serves as a transmission path for light from the film thickness detection sensor in optical end point detection. Although the endpoint detection window is circular in the third embodiment, it may be square, rectangular, polygonal, elliptical, or the like, if necessary.

In the third embodiment, in the process of manufacturing the polishing pad, when slicing, the end point detection window becomes recessed or cracked from the polishing layer, and when the dressing process is performed, From the viewpoint of improving flatness by suppressing the end-point detection window from becoming recessed or protruding from the polishing layer, parameters relating to the end-point detection window and the polishing layer are defined.

3.1.1.1. Pulsed NMR
Pulse NMR is one type of solid-state NMR, and is a method of detecting a response signal to a pulse to determine the ¹ H nuclear magnetic relaxation time (an index representing molecular mobility) of a sample. A free induction decay (FID signal) is obtained in response to the pulse.

Pulse NMR is an analytical method for evaluating the mobility of the polymer molecular chain as a whole system, and the mobility can be evaluated by measuring the relaxation time of the resin composition and the signal intensity at that time. In general, the lower the mobility of the polymer chain, the shorter the relaxation time, so the signal intensity decays faster, and the relative signal intensity decreases in a short time when the initial signal intensity is taken as 100%. In addition, the higher the mobility of the polymer chain, the longer the relaxation time, so the attenuation of the signal intensity becomes slower, and the relative signal intensity when the initial signal intensity is 100% gradually decreases over a long period of time.

For example, when measuring a resin, the obtained FID is the sum of the FIDs of multiple components with different relaxation times, and by separating this using the least squares method, the relaxation time of each component can be detected. Three-component approximation of the free induction decay curve at a given temperature obtained by measurement by the solid echo method of pulse NMR shows that the signal obtained by the measurement is the component with the lowest mobility (crystalline phase) in the sample, the intermediate It is possible to classify which of the motile component (intermediate phase) and the component with the highest motility (amorphous phase) is derived from, and to determine the abundance ratio of those components.

Specifically, the three components of the crystalline phase, the intermediate phase and the amorphous phase are approximated by fitting the free induction attenuation curve measured by the solid echo method of pulse NMR using the following formula (1). can be obtained, and each composition fraction can be obtained by approximation to the three components.
M(t)=αexp(-(1/2)(t/Tα) ² ) _sinbt /bt+βexp(-(1/Wa)(t/ _Tβ ) ^Wa )+ _γexp (-t/Tγ)... (Formula 1)
α: Composition fraction of crystal phase T _α : Relaxation time of crystal phase (unit: msec)
β: Composition fraction of intermediate phase T _β : Relaxation time of intermediate phase (unit: msec)
γ: Composition fraction of amorphous phase T _γ : Relaxation time of amorphous phase (unit: msec)
t: observation time (unit: msec)
Wa: shape factor b: shape factor

According to such pulse NMR measurement results, the motility of the polishing layer and endpoint detection window can be evaluated. In the third embodiment, at a temperature of 20° C. corresponding to dressing and a temperature of 80° C. corresponding to slicing, pulse NMR is used to evaluate that the polishing layer and endpoint detection window have similar motility.

Specifically, the ratio (Lp20/Lw20) of the abundance ratio Lw20 of the amorphous phase in the endpoint detection window to the abundance ratio Lp20 of the amorphous phase in the polishing layer at 20° C. is 0.5 to 2.0. , preferably 0.6 to 1.7, more preferably 0.7 to 1.5, still more preferably 0.8 to 1.2. When the ratio (Lp20/Lw20) is within the above range, the motility of the polishing layer and the material forming the endpoint detection window are close to each other during dressing. Therefore, the polishing layer and the endpoint detection window can be uniformly treated in the dressing process, and the flatness after the dressing process is further improved.

In addition, the ratio (Sp80/Sw80) of the abundance ratio Sw80 of the crystalline phase in the endpoint detection window to the abundance ratio Sp80 of the crystalline phase in the polishing layer at 80° C. is 0.5 to 2.0, preferably 0.5. It is 6 to 1.7, more preferably 0.9 to 1.5, still more preferably 1.0 to 1.3. When the ratio (Sp80/Sw80) is within the above range, the motility of the polishing layer and the material forming the endpoint detection window are close to each other in the slice. Therefore, in the slicing process, the polishing layer and the endpoint detection window can be uniformly processed, and the flatness after the slicing process is further improved.

The ratio (Mp20/Mw20) of the abundance ratio Mw20 of the intermediate phase in the endpoint detection window to the abundance ratio Mp20 of the intermediate phase in the polishing layer at 20° C. is preferably 0.7 to 1.5, more preferably 0. .7 to 1.3, more preferably 0.7 to 1.1. When the ratio (Mp20/Mw20) is within the above range, the polishing layer and the endpoint detection window can be uniformly treated in the dressing process, and the flatness after the dressing process tends to be further improved.

The ratio (Mp80/Mw80) of the abundance ratio Mw80 of the intermediate phase in the endpoint detection window to the abundance ratio Mp80 of the intermediate phase in the polishing layer at 80° C. is preferably 0.5 to 1.5, more preferably 0. .7 to 1.4, more preferably 0.8 to 1.3. When the ratio (Mp80/Mw80) is within the above range, the polishing layer and the end point detection window can be uniformly treated in the slicing process, and the flatness after the slicing process tends to be further improved.

The difference (|Lp20-Lw20|) between the abundance ratio Lw20 and the abundance ratio Lp20 is preferably 10 or less, more preferably 0 to 8.0, still more preferably 0 to 5.0. When the difference (|Lp20−Lw20|) is 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 (|Sp80-Sw80|) between the abundance ratio Sw80 and the abundance ratio Sw80 is preferably 15 or less, more preferably 0 to 12, and still more preferably 0 to 8.0. When the difference (|Sp80−Sw80|) is within the above range, the polishing layer and the endpoint detection window can be uniformly processed in the slicing process, and the flatness after the slicing process tends to be further improved.

The existence ratio Sw20 of the crystalline phase in the endpoint detection window at 20°C is preferably 30 to 65%, more preferably 35 to 60%, still more preferably 40 to 55%.

The abundance ratio Mw20 of the intermediate phase in the endpoint detection window at 20°C is preferably 15 to 45%, more preferably 20 to 40%, still more preferably 25 to 35%.

The abundance ratio Lw20 of the amorphous phase in the endpoint detection window at 20°C is preferably 10 to 40%, more preferably 15 to 35%, still more preferably 20 to 30%.

When the abundance ratio Sw20, the abundance ratio Mw20, and the abundance ratio Lw20 of the endpoint detection window at 20° C. are each within the above ranges, the polishing layer and the endpoint detection window can be treated homogeneously in the dressing process. Flatness after processing tends to be further improved. The sum of abundance ratio Sw20, abundance ratio Mw20, and abundance ratio Lw20 is 100%.

The existence ratio Sw80 of the crystalline phase in the endpoint detection window at 80°C is preferably 15 to 50%, more preferably 20 to 45%, still more preferably 25 to 40%.

The existence ratio Mw80 of the intermediate phase in the endpoint detection window at 80°C is preferably 10 to 35%, more preferably 15 to 30%, still more preferably 20 to 25%.

The abundance ratio Lw80 of the amorphous phase in the endpoint detection window at 80°C is preferably 30-60%, more preferably 35-55%, and still more preferably 40-50%.

When the abundance ratio Sw80, the abundance ratio Mw80, and the abundance ratio Lw80 of the endpoint detection window at 80° C. are each within the above ranges, the polishing layer and the endpoint detection window can be uniformly treated in the slicing process, and the slicing is performed. Flatness after processing tends to be further improved. The sum of abundance ratio Sw80, abundance ratio Mw80, and abundance ratio Lw80 is 100%.

The measurement conditions for pulse NMR measurement are not particularly limited, but measurements can be made under the conditions described in Examples.

3.1.1.3. Constituent Material The material constituting the endpoint detection window is not particularly limited as long as it is a transparent member that can function as a window. Examples include polyurethane resin WI, polyvinyl chloride resin, polyvinylidene fluoride resin, polyethersulfone resin, polystyrene resin, polyethylene resin, polytetrafluoroethylene resin, and the like. Among these, 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.

3.1.1.3.1. Structural Units Derived from Polyisocyanates Structural units derived from polyisocyanates are not particularly limited, but for example, structural units derived from alicyclic isocyanates, structural units derived from aliphatic isocyanates, and structures derived from aromatic isocyanates units. Among these, the polyurethane 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. This makes it easy to adjust each value related to pulse NMR within the above range, further improves transparency, and further improves flatness during dressing and slicing.

3.1.1.3.2. Structural Units Derived from Polyols Structural units derived from polyols are not particularly limited.

Among these, low-molecular-weight polyols having 3 or more hydroxyl groups are preferred, and glycerin is more preferred. By using such a low-molecular-weight polyol, the pulse NMR characteristics can be easily adjusted within the above range, the wear amount can be adjusted, the flatness can be further improved, the transparency can be further improved, and the durability of the window can be improved. Yellowing tends to be more improved.

The content of the structural unit derived from the low-molecular-weight polyol having 3 or more hydroxyl groups is preferably 8.0 to 30 parts by mass, more preferably 10 to 100 parts by mass, based on 100 parts by mass of the structural unit derived from the polyisocyanate. 25 parts by mass, more preferably 12.5 to 20 parts by mass. When the content of the structural unit derived from a low-molecular-weight polyol having three or more hydroxyl groups is within the above range, the pulse NMR characteristics can be easily adjusted within the above range, flatness can be further improved, and transparency can be improved. is further improved, and the yellowing resistance of the window tends to be further improved.

The number average molecular weight of the polymer polyol is preferably 300-3000, more preferably 500-2500. By using such a polymer polyol, the pulse NMR characteristics tend to be easily adjusted within the above range.

Among these, polyether polyol is preferred, and poly(oxytetramethylene) glycol is more preferred. By using such a polymer polyol, it is easy to adjust the pulse NMR characteristics within the above range. Further, the flatness can be further improved, the transparency is further improved, and the yellowing resistance of the window tends to be further improved.

The content of structural units derived from polyether polyol is preferably 60 to 130 parts by mass, preferably 65 to 120 parts by mass, more preferably 100 parts by mass of structural units derived from polyisocyanate. 70 to 110 parts by mass. When the content of the structural unit derived from the polyether polyol is within the above range, the pulse NMR characteristics can be easily adjusted within the above range, the flatness can be further improved, and the transparency can be further improved. It tends to improve the yellowing resistance of windows.

In addition, as the polyol, it is preferable to use a low-molecular-weight polyol and a high-molecular-weight polyol together, and it is more preferable to use a low-molecular-weight polyol having three or more hydroxyl groups and a polyether polyol together. This makes it easy to adjust the pulse NMR characteristics within the above range. Further, the flatness can be further improved, the transparency is further improved, and the yellowing resistance of the window tends to be further improved.

From the above viewpoint, the content of the polyether polyol is preferably 2.0 to 15.0 parts, more preferably 3.0 to 12.5 parts, relative to 1 part of the low-molecular-weight polyol having 3 or more hydroxyl groups. part, more preferably 4.0 to 9.0 parts.

3.1.2. Polishing Layer The polishing layer of the third embodiment has an opening in which the endpoint detection window is embedded. Although the position of the opening is not particularly limited, it is preferably provided at a position in the radial direction corresponding to the film thickness detection sensor 23 installed on the table 22 . Although the number of openings is not particularly limited, the openings are arranged at similar radial positions so that the windows pass over the film thickness detection sensor 23 multiple times when the polishing pad 10 attached to the table 22 rotates once. It is preferable to have a plurality of them.

3.1.2.1. Pulsed NMR
The existence ratio Sp20 of the crystal phase in the polishing layer is preferably 40 to 65%, preferably 45 to 60%, and preferably 50 to 55%.

The existence ratio Mp20 of the intermediate phase in the polishing layer is preferably 10-40%, preferably 15-35%, and preferably 20-30%.

The existence ratio Lp20 of the amorphous phase in the polishing layer is preferably 10 to 35%, preferably 15 to 30%, and preferably 20 to 25%.

When the abundance ratio Sp20, the abundance ratio Mp20, and the abundance ratio Lp20 of the endpoint detection window at 20° C. are each within the above ranges, the polishing layer and the endpoint detection window can be treated homogeneously in the dressing process. Flatness after processing tends to be further improved. The sum of abundance ratio Sp20, abundance ratio Mp20, and abundance ratio Lp20 is 100%.

The existence ratio Sp80 of the crystalline phase of the polishing layer is preferably 25 to 50%, preferably 30 to 45%, and preferably 35 to 40%.

The abundance ratio Mp80 of the intermediate phase in the polishing layer is preferably 10-40%, preferably 15-35%, and preferably 20-30%.

The abundance ratio Lp80 of the amorphous phase in the polishing layer is preferably 25-50%, preferably 30-45%, and preferably 35-40%.

When the abundance ratio Sp80, the abundance ratio Mp80, and the abundance ratio Lp80 of the endpoint detection window at 80° C. are each within the above ranges, the polishing layer and the endpoint detection window can be uniformly treated in the slicing process. Flatness after processing tends to be further improved. The sum of the abundance ratio Sp80, the abundance ratio Mp80, and the abundance ratio Lp80 is 100%.

3.1.2.2. Polyurethane Sheet Hereinafter, a polyurethane sheet is exemplified as an example of the polishing layer. The description of the polyurethane sheet is omitted because it includes the aspects described in the first embodiment.

3.1.3. Others The polishing pad of the third embodiment may have a cushion layer on the side opposite to the polishing surface of the polishing layer. The surface to be attached to the polishing machine) may have an adhesive layer. In this case, the cushion layer and the adhesive layer have openings at locations similar to where the endpoint detection windows of the polishing layer are located.

4. Fourth Embodiment 4.1. Polishing Pad The polishing pad of the fourth embodiment has a polishing layer and an end point detection window provided in the opening of the polishing layer, and has a tensile mode, a frequency of 1.6 Hz, 30 to 55 ° C., and a water immersion state. In the dynamic viscoelasticity measurement performed under the conditions, the ratio of the storage elastic modulus E′w40 of the endpoint detection window at 40° C. to the storage elastic modulus E′p40 of the polishing layer at 40° C. (E′p40/E′w40 ) is between 0.70 and 3.00.

FIG. 1 shows a schematic perspective view of the polishing pad of the fourth embodiment. As shown in FIG. 1, the polishing pad 10 of the fourth embodiment has a polishing layer 11 and an end point detection window 12, and optionally a cushion layer 13 on the side opposite to the polishing surface 11a. may have.

2 and 3 show cross-sectional views around the endpoint detection window 12 in FIG. As shown in FIGS. 2 and 3, an adhesive layer 14 may be provided between the polishing layer 11 and the cushion layer 13, and the surface of the cushion layer 13 is attached to the table 22 shown in FIG. An adhesive layer 15 may be provided for the purpose. The polishing surface 11a of the polishing pad of the fourth embodiment may be flat as shown in FIG. 2, or may be uneven with grooves 16 formed therein as shown in FIG. The grooves 16 may be formed with a plurality of grooves having various shapes such as concentric circles, grids, and radial grooves singly or in combination.

4.1.1. End Point Detection Window The end point detection window is a transparent member provided in the opening of the polishing layer, and serves as a transmission path for light from the film thickness detection sensor in optical end point detection. Although the endpoint detection window is circular in the fourth embodiment, it may be square, rectangular, polygonal, elliptical, or the like, if necessary.

In the fourth embodiment, the degree of abrasion of the endpoint detection window and the polishing layer during polishing is adjusted, and either the endpoint detection window or the polishing layer is excessively polished, thereby causing defects (surface defects) on the non-polished object. From the viewpoint of suppressing the occurrence of , the ratio of the storage elastic modulus E′ between the end point detection window and the polishing layer is defined.

4.1.1.1. Dynamic Viscoelasticity The endpoint detection window and the storage elastic modulus E′ of the polishing layer in the fourth embodiment are determined by dynamic viscoelasticity measurement performed under the conditions of tensile mode, frequency of 1.6 Hz, 30 to 55° C., and water immersion. be able to. In this embodiment, unless otherwise specified, it is assumed that the dynamic viscoelasticity measurement is performed in a submerged state.

　In the polishing process where the slurry and the polishing pad come into contact, the polishing surface is submerged. For this reason, in the fourth embodiment, the ratio of the dynamic viscoelasticity of the endpoint detection window and the polishing layer in the submerged state is defined at 40° C., which corresponds to the temperature during polishing. More specifically, in the dynamic viscoelasticity measurement performed under the conditions of tensile mode, frequency 1.6 Hz, 30 to 55 ° C., and immersion, the storage elastic modulus E'w40 of the endpoint detection window at 40 ° C. and 40 ° C. defines the ratio (E'p40/E'w40) to the storage elastic modulus E'p40 of the polishing layer at .

The ratio (E'p40/E'w40) is 0.70-3.00, preferably 0.80-2.50, more preferably 0.90-2.00. When the ratio (E'p40/E'w40) is within the above range, the properties of the end-point detection window and the polishing layer are similar during polishing, and the surface quality of the resulting polished object is further improved. As a result, the state of contact with the object to be polished (workpiece) during polishing is improved, and persistent pressing of polishing dust is suppressed, thereby suppressing the occurrence of scratches.

In the dynamic viscoelasticity measurement in the water-immersed state, the ratio of the storage elastic modulus E′w50 of the endpoint detection window at 50° C. to the storage elastic modulus E′p50 of the polishing layer at 50° C. (E′p50/E′w50) is preferably 0.70 to 5.00, more preferably 0.80 to 4.00, still more preferably 0.90 to 3.00. When the ratio (E'p50/E'w50) is within the above range, the characteristics of the end point detection window and the polishing layer are similar during polishing, so the surface quality of the resulting polished object tends to be further improved. .

In the dynamic viscoelasticity measurement in the water-immersed state, the difference between the loss coefficient tan δw30 of the endpoint detection window at 30° C. and the loss coefficient tan δp30 of the polishing layer at 30° C. (|tan δw30−tan δp30|) is preferably 0 to 0.0. 30, more preferably 0.05 to 0.30, still more preferably 0.05 to 0.20.

In the dynamic viscoelasticity measurement in the water-immersed state, the difference between the loss coefficient tan δw40 of the endpoint detection window at 40° C. and the loss coefficient tan δp40 of the polishing layer at 40° C. (|tan δw40−tan δp40|) is preferably 0 to 0.5. 40, more preferably 0.05 to 0.40, still more preferably 0.05 to 0.30.

In the dynamic viscoelasticity measurement in the water-immersed state, the difference between the loss coefficient tan δw50 of the endpoint detection window at 50° C. and the loss coefficient tan δp50 of the polishing layer at 50° C. (|tan δw50−tan δp50|) is preferably 0 to 0.5. 50, more preferably 0.05 to 0.50, more preferably 0.05 to 0.40,

Difference (|tan δw30-tan δp30|), difference (|tan δw40-tan δp40|), and difference (|tan δw50-tan δp50|) are each within the above range, so that the properties of the end point detection window and the polishing layer during polishing are similar. Therefore, the surface quality of the resulting polished object tends to be further improved.

The storage elastic modulus E′w40 at 40° C. of the endpoint detection window in the submerged state is preferably 6.0 to 50×10 ⁷ Pa, more preferably 8.0 to 40×10 ⁷ Pa, still more preferably It is 10 to 30×10 ⁷ Pa.

The storage elastic modulus E′w50 at 50° C. of the endpoint detection window in the submerged state is preferably 2.0 to 40×10 ⁷ Pa, more preferably 3.0 to 30×10 ⁷ Pa, still more preferably 4.0 to 20×10 ⁷ Pa.

The tan δw40 at 40° C. of the endpoint detection window in the submerged state is preferably 0.1 to 0.7, more preferably 0.1 to 0.6, still more preferably 0.1 to 0.5. .

The tan δw50 at 50° C. of the endpoint detection window in the submerged state is preferably 0.1 to 0.6, more preferably 0.1 to 0.5, still more preferably 0.1 to 0.4. .

When E′w40, E′w50, tan δw40, and tan δw50 are each within the above ranges, the properties of the end point detection window and the polishing layer during polishing are similar, so that the surface quality of the object to be polished is improved. tend to improve.

4.1.1.3. Constituent Material The material constituting the endpoint detection window is not particularly limited as long as it is a transparent member that can function as a window. Examples include polyurethane resin WI, polyvinyl chloride resin, polyvinylidene fluoride resin, polyethersulfone resin, polystyrene resin, polyethylene resin, polytetrafluoroethylene resin, and the like. Among these, 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.

4.1.1.3.1. Structural Units Derived from Polyisocyanates Structural units derived from polyisocyanates are not particularly limited, but for example, structural units derived from alicyclic isocyanates, structural units derived from aliphatic isocyanates, and structures derived from aromatic isocyanates units. Among these, the polyurethane 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. As a result, the dynamic viscoelastic properties are easily adjusted within the above range, the transparency is further improved, and the surface quality tends to be further improved.

4.1.1.3.2. Structural Units Derived from Polyols Structural units derived from polyols are not particularly limited.

Among these, low-molecular-weight polyols having 3 or more hydroxyl groups are preferred, and glycerin is more preferred. By using such a low-molecular-weight polyol, the dynamic viscoelastic properties can be easily adjusted within the above range, the wear amount can be adjusted, 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-weight polyol having 3 or more hydroxyl groups is preferably 7.5 to 30 parts by mass, more preferably 10 to 100 parts by mass, relative to 100 parts by mass of the structural unit derived from the polyisocyanate. 25 parts by mass, more preferably 12.5 to 20 parts by mass. When the content of the structural unit derived from a low-molecular-weight polyol having three or more hydroxyl groups is within the above range, the dynamic viscoelastic properties are easily adjusted within the above range, the transparency is further improved, and the surface quality is improved. tend to improve.

The number average molecular weight of the polymer polyol is preferably 300-3000, more preferably 500-2500. By using such a polymer polyol, the dynamic viscoelastic properties tend to be easily adjusted within the above range.

Among these, polyether polyol is preferred, and poly(oxytetramethylene) glycol is more preferred. By using such a polymer polyol, it is easy to adjust the dynamic viscoelastic properties within the above range. In addition, the transparency tends to be further improved, and the yellowing resistance of windows tends to be further improved.

The content of structural units derived from polyether polyol is preferably 60 to 130 parts by mass, preferably 65 to 120 parts by mass, more preferably 70 parts by mass, based on 100 parts by mass of structural units derived from polyisocyanate. ~110 parts by mass. When the content of the structural unit derived from the polyether polyol is within the above range, the dynamic viscoelastic properties are easily adjusted within the above range, the transparency is further improved, and the yellowing resistance of the window is further improved. tend to

In addition, as the polyol, it is preferable to use a low-molecular-weight polyol and a high-molecular-weight polyol together, and it is more preferable to use a low-molecular-weight polyol having three or more hydroxyl groups and a polyether polyol together. As a result, the dynamic viscoelastic property can be easily adjusted within the above range, the transparency is further improved, and the yellowing resistance of the window tends to be further improved.

4.1.2. Polishing Layer The polishing layer of the fourth embodiment has an opening in which the endpoint detection window is embedded. Although the position of the opening is not particularly limited, it is preferably provided at a position in the radial direction corresponding to the film thickness detection sensor 23 installed on the table 22 . Although the number of openings is not particularly limited, the openings are arranged at similar radial positions so that the windows pass over the film thickness detection sensor 23 multiple times when the polishing pad 10 attached to the table 22 rotates once. It is preferable to have a plurality of them.

4.1.2.1. Dynamic Viscoelasticity The storage elastic modulus E′p40 at 40° C. of the polishing layer in a water-immersed state is preferably 10 to 40×10 ⁷ Pa, more preferably 15 to 35×10 ⁷ Pa, still more preferably 20. ˜30×10 ⁷ Pa.

The storage elastic modulus E′p50 at 50° C. of the polishing layer in the submerged state is preferably 50 to 35×10 ⁷ Pa, more preferably 10 to 30×10 ⁷ Pa, still more preferably 15 to 25×10. ⁷ Pa.

The tan δp40 at 40°C of the polishing layer in the submerged state is preferably 0.01 to 0.25, more preferably 0.03 to 0.20, still more preferably 0.05 to 0.15.

The tan δp50 at 50°C of the polishing layer in the submerged state is preferably 0.01 to 0.25, more preferably 0.03 to 0.20, still more preferably 0.05 to 0.15.

When E' _p40 , E' _p50 , tanδ _p40 , and tanδ _p50 are each within the above ranges, the end point detection window during polishing and the characteristics of the polishing layer are similar, and the surface quality of the resulting polished object is improved. tend to improve.

4.1.2.2. Polyurethane Sheet Hereinafter, a polyurethane sheet is exemplified as an example of the polishing layer. The description of the polyurethane sheet is omitted because it includes the aspects described in the first embodiment.

4.1.3. Others The polishing pad of the fourth embodiment may have a cushion layer on the side opposite to the polishing surface of the polishing layer. The surface to be attached to the polishing machine) may have an adhesive layer. In this case, the cushion layer and the adhesive layer have openings at locations similar to where the endpoint detection windows of the polishing layer are located.

5. Method for Manufacturing Polishing Pad The method for manufacturing the polishing pad of the first to fourth embodiments is not particularly limited, but for example, a polishing layer is formed in a mold in which a window member serving as an endpoint detection window is fixed. A step of filling and curing a resin composition to obtain a resin block in which a window member is embedded, and a step of slicing the obtained resin block to obtain a polyurethane sheet having an endpoint detection window in the opening. If necessary, the polished surface of the resulting polyurethane sheet may be dressed.

The temperature for slicing is preferably 70°C to 100°C. Also, the temperature in the dressing treatment is preferably 20°C to 30°C. This tends to further improve flatness.

6. Method for producing a polished object The method for producing a polished object according to the first to fourth embodiments includes a polishing step of polishing an object to be polished using the polishing pad 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.

6.1. Polishing process The polishing process may be primary lapping polishing (rough lapping), secondary lapping (finish lapping), primary polishing (rough polishing), or secondary polishing (finish polishing). ), or may also serve as polishing. Here, "lapping" refers to polishing at a relatively high rate using coarse abrasive grains, and "polishing" refers to increasing the surface quality at a relatively low rate using fine abrasive grains. Say to polish for.

Among these, the polishing pads of the first to fourth embodiments are preferably used for chemical mechanical polishing (CMP). The methods for manufacturing the polished objects of the first to fourth embodiments will be described below using chemical mechanical polishing as an example, but the methods for manufacturing the polished objects of the first to fourth embodiments are not limited to the following.

The object to be polished is not particularly limited, but for example, materials such as semiconductor devices and electronic components, particularly Si substrates (silicon wafers), SiC (silicon carbide) substrates, GaAs (gallium arsenide) substrates, glass, hard disks and LCDs. Thin substrates (objects to be polished) such as substrates for (liquid crystal displays) can be mentioned. In particular, semiconductor devices having metal wiring such as W (tungsten) and Cu (copper) are mentioned.

A conventionally known method can be used as the polishing method, and is not particularly limited. For example, first, an object to be polished held on a holding surface plate arranged to face the polishing pad is pressed against the polishing surface, and the polishing pad and/or the holding surface plate are rotated while slurry is supplied from the outside. Let The polishing pad and the holding platen may rotate in the same direction or in opposite directions at different rotational speeds. Further, the object to be polished may be polished while moving (rotating) inside the frame during the polishing process.

Depending on the object to be polished, polishing conditions, etc., the slurry may contain chemical components such as water and an oxidizing agent represented by hydrogen peroxide, additives, abrasive grains (abrasive particles; for example, SiC, SiO ₂ , Al ₂ O ₃ , CeO ₂ ) and the like.

6.2. End Point Detection Step The method of manufacturing a polished workpiece according to the first to fourth embodiments has an end point detection step of detecting the end point by an optical end point detection method in the polishing step. Specifically, a conventionally known method can be used as the end point detection method by the optical end point detection method.

FIG. 4 shows a schematic diagram of the endpoint detection method of the optical endpoint detection method. This schematic diagram shows a chemical mechanical polishing process in which a wafer W held by a top ring 21 is pressed onto a polishing pad 10 attached on a table 22 while flowing a slurry 24 thereon, and the uneven film on the surface of the wafer W is scraped and flattened. . The polishing apparatus 20 mounts a film thickness detection sensor 23 for monitoring the film thickness on the table 22 in order to detect the end point of the predetermined film thickness at the same time as flattening and terminate the process with high accuracy. The film thickness detection sensor 23 can detect the polishing end point by, for example, irradiating the polishing surface of the wafer W with light and measuring and analyzing the spectral intensity characteristics of the reflected light.

More specifically, the film thickness detection sensor 23 causes light to enter the surface of the wafer W through the end point detection window 12, and the light reflected by the film on the wafer W (wafer surface) and the film on the wafer W are detected. A film thickness change can be detected by detecting the strength of the reflection intensity caused by the phase difference with respect to the light reflected at the interface between the wafer and the substrate.

Hereinafter, the present invention will be described more specifically using examples and comparative examples. The present invention is by no means limited by the following examples. In addition, "part" shall mean a mass part.

[Example A]
[Manufacturing Example A1: End Point 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 are reacted to detect the end point. A transparent member to be the window A1 was obtained.

[Manufacturing example A2: end point detection window A2]
100 parts of 4,4' methylene bis(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 allowed to react to obtain a transparent member serving as the endpoint detection window A2.

[Manufacturing example A3: end point 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 that will serve as the endpoint detection window A3.

[Manufacturing Example A4: End Point 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 are reacted to detect the end point. A transparent member to be the window A4 was obtained.

[Example A1]
2,4-tolylene diisocyanate (2,4-TDI), poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 650, poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and diethylene glycol (DEG ) is reacted with 100 parts of a urethane prepolymer having an NCO equivalent of 455, and 2.7 parts of unexpanded hollow fine particles (average particle diameter: 8.5 μm) having a shell portion made of an acrylonitrile-vinylidene chloride copolymer are added. By mixing, a urethane prepolymer mixture was obtained. The obtained urethane prepolymer mixed liquid was charged into the first liquid tank and kept at 60°C. Separately from the first liquid tank, put 25.8 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylenebis-o-chloroaniline) (MOCA) as a curing agent into the second liquid tank, The mixture was heated and melted at 120° C., mixed, and degassed under reduced pressure to obtain a curing agent melt.

Next, the liquids in the first liquid tank and the second liquid tank were injected from respective inlets of a mixer provided with two inlets, and stirred and mixed to obtain a mixed liquid.

Then, the obtained mixed liquid was cast into a mold in which the endpoint detection window A1 obtained as described above was installed in advance, and was primarily cured at 80°C for 30 minutes. The formed block-shaped molding was extracted from the mold and subjected to secondary curing in an oven at 120° C. for 4 hours to obtain a urethane resin block. The resulting urethane resin block was allowed to cool to 25°C.

After that, it was heated again in an oven at 120°C for 5 hours, then subjected to slicing, and the sliced surface was subjected to grinding (buffing) as necessary to obtain a foamed polyurethane sheet. A double-faced tape was attached to the rear surface of the obtained polyurethane sheet, a cushion layer was attached thereto, and a double-sided tape was attached to the surface of the cushion layer to obtain a polishing pad.

When evaluating the cross section around the end point detection window after the dressing process, the polishing pad obtained as described above was subjected to the dressing process under the following conditions.
(dress condition)
Polishing machine used: Speedfam, trade name “FAM-12BS”
Surface plate rotation speed (polishing pad rotation speed): 50 rpm
Flow rate: 100 ml/min (Pure water at 20° C. was dropped from the rotation center of the polishing pad.)
Dresser: 3M diamond dresser, model number "A188"
Dresser rotation speed: 100 rpm
Dressing pressure: 0.115 kg/cm2
Direction of dresser rotation: 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 endpoint 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 endpoint 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 endpoint detection window A4 of Production Example A4 was used.

[Dynamic viscoelasticity measurement]
Based on the following conditions, a dry polyurethane sheet was held for 40 hours in a constant temperature and humidity chamber at a temperature of 23 ° C (± 2 ° C) and a relative humidity of 50% (± 5%). A dynamic viscoelasticity measurement was performed in an atmosphere (dry state). The sample size of the endpoint detection window was 5 cm long×0.5 cm wide×0.125 cm thick, and the sample size of the polishing layer was 5 cm long×0.5 cm wide×0.13 cm thick.
(Measurement condition)
Measuring device: RSA III (manufactured by TA Instruments)
Test length: 1cm
Test mode: Tensile Frequency: 1.0Hz
Temperature range: 10-100°C
Heating rate: 3.0°C/min
Strain range: 0.10%
Initial load: 300g
Measurement interval: 1.5 points/°C

[D hardness]
The D hardness was measured according to JIS K6253. At the time of measurement, a D hardness tester manufactured by Teclock Co., Ltd. was used, and the sample was a stack of four endpoint detection windows (thickness of about 0.125 cm (1.25 mm)) described in Comparative Example A and Example A, and at least the total thickness It was set to be 0.45 cm (4.5 mm) or more. In addition, the sample used was one which was allowed to stand for 30 minutes in a constant temperature and humidity chamber at 20°C or 80°C.

[Cross-section evaluation]
For each pad obtained as described above, the end point detection window periphery (area surrounded by the dashed line S in FIG. 2) after slicing and before dressing (evaluation A1), and the end point detection after dressing A cross section (evaluation A2) around the window (the portion surrounded by the dashed line S in FIG. 2) is measured with a laser microscope (VK-X1000, manufactured by KEYENCE) with a diameter of about 14 mm × 1 mm with respect to the surface of the diameter portion of the endpoint detection window. The range was magnified 200 times and observed in the coupled mode, and profile measurement of height information was performed based on the obtained laser image.

The results are shown in Figures 5A-D and 6A-D. 5A to 5D and 6A to 6D show the cross-sectional measurement results of two endpoint detection windows, and the cross-sectional measurement results of each endpoint detection window in the slicing direction and the direction perpendicular to the slicing direction. is shown.

In the evaluation A1, if the end point detection window was within ±50 μm from the polished surface, it was evaluated as ◯, and otherwise as x. In the evaluation A2, if the cross-sectional image is flat (the height is the same from the edge to the center), it is rated as ◯, and if it is convex (the height is increased from the edge to the center), it is rated as x. .

[Example B]
[Manufacturing Example B1: End Point 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 are reacted to detect the end point. A transparent member to be the window B1 was obtained.

[Manufacturing Example B2: End Point 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 are reacted to detect the end point. A transparent member to be the window B2 was obtained.

[Manufacturing Example B3: End Point 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 are reacted to detect the end point. A transparent member to be the window B3 was obtained.

[Manufacturing Example B4: End Point 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 are reacted to detect the end point. A transparent member to be the window B4 was obtained.

[Manufacturing Example B5: End Point 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 are reacted to detect the end point. A transparent member to be the window B5 was obtained.

[Manufacturing Example B6: End Point 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 , to obtain a transparent member that will serve as the endpoint detection window B6.

[Example B1]
2,4-tolylene diisocyanate (2,4-TDI), poly(oxytetramethylene) glycol (PTMG) with an average molecular weight of 650, poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and diethylene glycol (DEG) 2.7 parts of unexpanded hollow fine particles (average particle size: 8.5 μm) whose shell is made of acrylonitrile-vinylidene chloride copolymer are added and mixed to 100 parts of a urethane prepolymer having an NCO equivalent of 455 obtained by reacting to obtain a urethane prepolymer mixture. The obtained urethane prepolymer mixed liquid was charged into the first liquid tank and kept at 60°C. Separately from the first liquid tank, put 25.8 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylenebis-o-chloroaniline) (MOCA) as a curing agent into the second liquid tank, The mixture was heated and melted at 120° C., mixed, and degassed under reduced pressure to obtain a curing agent melt.

Then, the obtained mixed liquid was poured into a mold in which the endpoint detection window B1 obtained as described above was installed in advance, and was primarily cured at 80°C for 30 minutes. The formed block-shaped molding was extracted from the mold and subjected to secondary curing in an oven at 120° C. for 4 hours to obtain a urethane resin block. The resulting urethane resin block was allowed to cool to 25°C.

After that, it was heated again in an oven at 120°C for 5 hours, sliced, and the sliced surface was ground (buffed) to obtain a foamed polyurethane sheet. A double-faced tape was attached to the rear surface of the obtained polyurethane sheet, a cushion layer was attached thereto, and a double-sided tape was attached to the surface of the cushion layer to obtain a polishing pad.

[Example B2]
2,4-tolylene diisocyanate (2,4-TDI), poly(oxytetramethylene) glycol (PTMG) with an average molecular weight of 650, poly(oxytetramethylene) glycol (PTMG) with 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) whose shell part is made of acrylonitrile-vinylidene chloride copolymer are added and mixed. to obtain a urethane prepolymer mixture. The obtained urethane prepolymer mixed liquid was charged into the first liquid tank and kept at 60°C. Separately from the first liquid tank, put 28.0 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylenebis-o-chloroaniline) (MOCA) as a curing agent into the second liquid tank, A polishing pad was obtained in the same manner as in Example B1, except that the curing agent melt obtained by heating and melting at 120° C., and then degassing under reduced pressure, and the endpoint detection window B2 were used.

[Example B3]
2,4-tolylene diisocyanate (2,4-TDI), poly(oxytetramethylene)glycol (PTMG) with an average molecular weight of 650 and diethylene glycol (DEG) are reacted to 100 parts of a urethane prepolymer having an NCO equivalent of 460, 2.8 parts of expanded hollow fine particles (average particle size: 20 μm) having a shell portion made of an acrylonitrile-vinylidene chloride copolymer were added and mixed to obtain a urethane prepolymer mixture. The obtained urethane prepolymer mixed liquid was charged into the first liquid tank and kept at 60°C. Separately from the first liquid tank, 25.5 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylenebis-o-chloroaniline) (MOCA) and 8.5 parts of polypropylene glycol were added as curing agents. In the same manner as in Example B1, except that the curing agent melt obtained by putting it in the second liquid tank, heating and melting at 120 ° C. and mixing, and further degassing under reduced pressure and using the end point detection window B3, A polishing pad was obtained.

[Example B4]
A polishing pad was obtained in the same manner as in Example B1, except that the endpoint detection window B2 was used.

[Example B5]
A polishing pad was obtained in the same manner as in Example B1, except that the endpoint detection window B3 was used.

[Example B6]
A polishing pad was obtained in the same manner as in Example B1, except that the endpoint detection window B4 was used.

[Example B7]
A polishing pad was obtained in the same manner as in Example B2, except that the endpoint detection window B4 was used.

[Comparative Example B1]
A polishing pad was obtained in the same manner as in Example B1, except that the endpoint detection window B5 was used.

[Comparative Example B2]
A polishing pad was obtained in the same manner as in Example B1, except that the endpoint detection window B6 was used.

[Dynamic viscoelasticity measurement]
Based on the following conditions, the polishing layer and endpoint detection window in a dry state were held for 40 hours in a constant temperature and humidity chamber at a temperature of 23°C (±2°C) and a relative humidity of 50% (±5%). was used as a sample, and dynamic viscoelasticity was measured under normal air atmosphere (dry state). The sample size of the endpoint detection window was 5 cm long×0.5 cm wide×0.125 cm thick, and the sample size of the polishing layer was 5 cm long×0.5 cm wide×0.13 cm thick.
(Measurement condition)
Measuring device: RSA III (manufactured by TA Instruments)
Test length: 1cm
Test mode: Tensile Frequency: 1.0Hz
Temperature range: 10-100°C
Heating rate: 3.0°C/min
Strain range: 0.10%
Initial load: 300g
Measurement interval: 1.5 points/°C

[D hardness]
The D hardness was measured according to JIS K6253. For the measurement, a D hardness tester manufactured by Teclock Co., Ltd. was used. The thickness was set to 0.45 cm (4.5 mm) or more. In addition, the sample used was one that had been allowed to stand for 30 minutes in a constant temperature and humidity chamber at 20°C.

[Evaluation B: Surface Quality Confirmation Test]
A polishing pad was set at a predetermined position of a polishing apparatus via a double-sided tape having an acrylic adhesive, and the Cu film substrate was subjected to polishing under the following conditions.
(polishing conditions)
Polishing machine: F-REX300X (manufactured by Ebara Corporation)
Disk: A188 (manufactured by 3M)
Rotation speed: (Surface plate) 85 rpm, (Top ring) 86 rpm
Polishing pressure: 3.5 psi
Abrasive temperature: 20°C
Abrasive discharge rate: 200ml/min
Abrasive: CSL-9044C (manufactured by Fujimi Corporation) (CSL-9044C undiluted solution: pure water = 1:9 weight ratio mixed solution is used)
Object to be polished: Cu film substrate Polishing time: 60 seconds Pad break: 35N 10 minutes Conditioning: Ex-situ, 35N, 4 scans

Defects with a size of 155 nm or more (surface defects ) were detected and evaluated. The surface quality was evaluated based on the confirmation results of defects (surface defects).

[Example C]
[Manufacturing Example C1: End Point 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 are reacted to form an endpoint detection window. A transparent member of C1 was obtained.

[Manufacturing Example C2: End Point 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 are reacted to form an endpoint detection window. A transparent member of C2 was obtained.

[Manufacturing Example C3: End Point Detection Window C3]
100 parts of 4,4′ methylene bis(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; was reacted to obtain a transparent member that will serve as the endpoint detection window C3.

[Example C1]
2,4-tolylene diisocyanate (2,4-TDI), poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 650, poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and diethylene glycol (DEG ) is reacted with 100 parts of a urethane prepolymer having an NCO equivalent of 420, and 2.9 parts of unexpanded hollow fine particles (average particle diameter: 8.5 μm) having a shell made of an acrylonitrile-vinylidene chloride copolymer are added. By mixing, a urethane prepolymer mixture was obtained. The obtained urethane prepolymer mixed liquid was charged into the first liquid tank and kept at 60°C. Separately from the first liquid tank, put 28.0 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylenebis-o-chloroaniline) (MOCA) as a curing agent into the second liquid tank, The mixture was heated and melted at 120° C., mixed, and degassed under reduced pressure to obtain a curing agent melt.

Then, the obtained mixed liquid was cast into a mold in which the endpoint detection window C1 obtained as described above was installed in advance, and was primarily cured at 80°C for 30 minutes. The formed block-shaped molding was extracted from the mold and subjected to secondary curing in an oven at 120° C. for 4 hours to obtain a urethane resin block. The resulting urethane resin block was allowed to cool to 25°C.

[Example C2]
A polishing pad was obtained in the same manner as in Example C1, except that the endpoint 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 endpoint detection window C3 of Production Example C3 was used.

[Pulse NMR]
Apparatus: Minispec MQ20 (manufactured by Bruker Biospin Co., Ltd.)
^Nuclide : 1H
Measurement: _T2
Measurement method: Solid echo method Accumulation times: 256 times Repeat time: 1.0 sec
Measurement temperature: 20°C, 80°C (measurement was started 60 minutes after the device temperature reached the measurement temperature and the sample was set)
Using the apparatus and conditions described above, 10 sample pellets of about 50 mg each having a diameter of 8 mm were prepared, filled in a sample tube, and subjected to pulse NMR measurement to obtain an attenuation curve.

The obtained attenuation curve was fitted and analyzed using equation (1) to obtain the relaxation times of the crystalline phase, the intermediate phase and the amorphous phase in the polyurethane resin. For fitting and analysis, the software attached to the measuring device was used.
M(t)=αexp(-(1/2)(t/Tα) ² ) _sinbt /bt+βexp(-(1/Wa)(t/ _Tβ ) ^Wa )+ _γexp (-t/Tγ)... formula (1)
α: Composition fraction of crystal phase T _α : Relaxation time of crystal phase (unit: msec)
β: Composition fraction of intermediate phase T _β : Relaxation time of intermediate phase (unit: msec)
γ: Composition fraction of amorphous phase T _γ : Relaxation time of amorphous phase (unit: msec)
t: observation time (unit: msec)
Wa: shape factor b: shape factor

[Cross-section evaluation]
For each pad obtained as described above, the end point detection window periphery (the portion surrounded by the dashed line S in FIG. 2) after slicing and before dressing (evaluation C1), and the end point detection after dressing A cross section (evaluation C2) around the window (the portion surrounded by the dashed line S in FIG. 2) is measured with a laser microscope (VK-X1000, manufactured by KEYENCE) at a size of about 14 mm × 1 mm with respect to the surface of the diameter portion of the endpoint detection window. The range was magnified 200 times and observed in the coupled mode, and profile measurement of height information was performed based on the obtained laser image.

The results are shown in Figures 7A-C and Figures 8A-C. 7A to C and FIGS. 8A to C show the cross-sectional measurement results of two end-point detection windows, which are the results of cross-sectional measurement in the slicing direction and a direction orthogonal to the slicing direction for each end-point detection window. is shown.

In evaluation C1, if the end point detection window was within ±50 μm from the polished surface, it was evaluated as ◯, and otherwise as x. In the evaluation C2, if the cross-sectional image was flat (the height was the same from the edge to the center), it was rated as ◯, and if it was convex (the height increased from the edge to the center), it was rated as x. .

[Example D]
[Manufacturing Example D1: End Point 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 are reacted to form an endpoint detection window. A transparent member of D1 was obtained.

[Manufacturing Example D2: End Point 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 are reacted to form an endpoint detection window. A transparent member of D2 was obtained.

[Manufacturing Example D3: End Point Detection Window D3]
100 parts of 4,4′ methylene bis(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; was reacted to obtain a transparent member that will serve as the endpoint detection window D3.

[Example D1]
2,4-tolylene diisocyanate (2,4-TDI), poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 650, poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and diethylene glycol (DEG ) is reacted with 100 parts of a urethane prepolymer having an NCO equivalent of 420, and 2.9 parts of unexpanded hollow fine particles (average particle diameter: 8.5 μm) having a shell made of an acrylonitrile-vinylidene chloride copolymer are added. By mixing, a urethane prepolymer mixture was obtained. The obtained urethane prepolymer mixed liquid was charged into the first liquid tank and kept at 60°C. Separately from the first liquid tank, put 28.0 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylenebis-o-chloroaniline) (MOCA) as a curing agent into the second liquid tank, The mixture was heated and melted at 120° C., mixed, and degassed under reduced pressure to obtain a curing agent melt.

Then, the obtained mixed liquid was cast into a mold in which the end point detection window D1 obtained as described above was installed in advance, and was primarily cured at 80°C for 30 minutes. The formed block-shaped molding was extracted from the mold and subjected to secondary curing in an oven at 120° C. for 4 hours to obtain a urethane resin block. The resulting urethane resin block was allowed to cool to 25°C.

[Dynamic viscoelasticity measurement]
Dynamic viscoelasticity was measured under the following conditions. First, the sample was immersed in water at a temperature of 23°C for 3 days. Using the obtained sample, dynamic viscoelasticity measurement was performed in water (immersion state). The sample size of the endpoint detection window was 5 cm long×0.5 cm wide×0.13 cm thick, and the sample size of the polishing layer was 5 cm long×0.5 cm wide×0.13 cm thick.
(Measurement condition)
Measuring device: RSA G2 (manufactured by TA Instruments)
Test length: 1cm
Sample pretreatment: Hold in water at 23°C for 3 days Test mode: Tensile Frequency: 1.6Hz
Temperature range: 30-55°C
Heating rate: 0.3°C/min
Strain range: 0.10%
Initial load: 300g
Measurement interval: 200 points/°C

[Surface Quality Confirmation Test]
A polishing pad was set at a predetermined position of a polishing apparatus via a double-sided tape having an acrylic adhesive, and the Cu film substrate was subjected to polishing under the following conditions.
(polishing conditions)
Polishing machine: F-REX300X (manufactured by Ebara Corporation)
Disk: A188 (manufactured by 3M)
Rotation speed: (Surface plate) 85 rpm, (Top ring) 86 rpm
Polishing pressure: 3.5 psi
Abrasive temperature: 20°C
Abrasive discharge rate: 200ml/min
Abrasive: CSL-9044C (manufactured by Fujimi Corporation) (CSL-9044C undiluted solution: pure water = 1:9 weight ratio mixed solution is used)
Object to be polished: Cu film substrate Polishing time: 60 seconds Pad break: 35N 10 minutes Conditioning: Ex-situ, 35N, 4 scans

The "ratio p/w" in Table 4 is the ratio of the storage elastic modulus E'w of the endpoint detection window and the storage elastic modulus E'p of the polishing layer at the same temperature, or tan δw of the endpoint detection window and The ratio to tan δp of the polishing layer is shown. For example, according to Table 1, the ratio (E'p40/E'w40) of Example D1 is 0.95, the ratio (E'p40/E'w40) of Example D2 is 1.62, The ratio (E'p40/E'w40) of Comparative Example D1 is 4.90.

"Difference |pw|" in Table 4 is the difference between the storage elastic modulus E'w of the endpoint detection window and the storage elastic modulus E'p of the polishing layer at the same temperature, or The difference between tan δw and tan δp of the polishing layer is shown. For example, according to Table 1, the difference in Example D1 (|tan δw30-tan δp30|) is 0.07, the difference in Example D2 (|tan δw30-tan δp30|) is 0.12, and the difference in Comparative Example D1 is The difference (|tan δw30-tan δp30|) is 0.34.

The polishing pad of the present invention has industrial applicability as a pad suitable for polishing semiconductor wafers and the like.

DESCRIPTION OF SYMBOLS 10... Polishing pad, 11... Polishing layer, 11a... Polishing surface, 12... End point detection window, 13... Cushion layer, 14, 15... Adhesive layer, 16... Groove, 20... Polishing device, 21... Top ring, 22... Table , 23... Film thickness detection sensor, 24... Slurry, W... Wafer

Claims

having a polishing layer and an endpoint detection window provided in an opening of the polishing layer;
In the dynamic viscoelasticity measurement of the endpoint detection window performed under the conditions of tensile mode, frequency of 1.0 Hz, and 10 to 100 ° C., the storage elastic modulus E′ W90 at 90 ° C. is 1.0 × 10 Pa or more,
The D hardness (D W80 ) of the endpoint detection window at 80° C. is 40 or more,
The endpoint detection window has a D hardness (D W20 ) at 20° C. of 40 to 90.
polishing pad.
wherein the endpoint detection window comprises a polyurethane resin WI;
The polishing pad according to claim 1.
The polyurethane resin WI contains structural units derived from an alicyclic isocyanate and/or an aliphatic isocyanate,
The polishing pad according to claim 2.
The polyurethane resin WI contains structural units derived from a compound having 3 or more hydroxyl groups,
The polishing pad according to claim 2 or 3.
In the dynamic viscoelasticity measurement of the endpoint detection window, the storage elastic modulus E′ W30 at 30° C. is 60×10 7 to 100×10 7 Pa.
The polishing pad according to any one of claims 1-4.
In the dynamic viscoelasticity measurement of the endpoint detection window, the peak temperature of tan δ is 70 to 100 ° C.
The polishing pad according to any one of claims 1-5.
The polishing layer contains a polyurethane resin P and hollow fine particles dispersed in the polyurethane resin P.
The polishing pad according to any one of claims 1-6.
having a polishing layer and an endpoint detection window provided in an opening of the polishing layer;
In the dynamic viscoelasticity measurement performed under the conditions of tensile mode, frequency 1.0 Hz, 10 to 100 ° C., the storage elastic modulus E'W30 at 30 ° C. of the end point detection window and the storage elastic modulus E at 30 ° C. of the polishing layer ' P30 ratio (E' P30 /E' W30 ) is 0.60 to 1.50,
polishing pad.
wherein the endpoint detection window comprises a polyurethane resin WI;
The polishing pad according to claim 8.
The polyurethane resin WI contains structural units derived from an alicyclic isocyanate and/or an aliphatic isocyanate,
The polishing pad according to claim 8.
The polyurethane resin WI contains structural units derived from a compound having 3 or more hydroxyl groups,
The polishing pad according to claim 9 or 10.
In the dynamic viscoelasticity measurement, the ratio of the storage elastic modulus E'W50 at 50°C of the end point detection window to the storage elastic modulus E'P50 at 50°C of the polishing layer ( E'P50 / E'W50 ) is , between 0.70 and 2.00;
The polishing pad according to any one of claims 8-11.
In the dynamic viscoelasticity measurement of the endpoint detection window, the storage elastic modulus E′ W30 at 30° C. is 10×10 7 to 60×10 7 Pa.
The polishing pad according to any one of claims 8-12.
The endpoint detection window has a D hardness (D W20 ) at 20° C. of 40 to 70.
The polishing pad according to any one of claims 8-13.
The polishing layer contains a polyurethane resin P and hollow fine particles dispersed in the polyurethane resin P.
The polishing pad according to any one of claims 8-14.
having a polishing layer and an endpoint detection window provided in an opening of the polishing layer;
The spin-spin relaxation free induction decay curve of 1H obtained by measurement by the Solid Echo method using pulsed NMR is divided into 3 phases derived from the three components of the crystalline phase, intermediate phase, and amorphous phase in order of shortest relaxation time. When the waveform is separated into two curves,
a ratio (Lp20/Lw20) of the abundance ratio Lw20 of the amorphous phase in the endpoint detection window to the abundance ratio Lp20 of the amorphous phase in the polishing layer at 20° C. is 0.5 to 2.0;
The ratio (Sp80/Sw80) of the crystalline phase abundance ratio Sw80 of the endpoint detection window to the crystalline phase abundance ratio Sp80 of the polishing layer at 80° C. is 0.5 to 2.0.
polishing pad.
The ratio (Mp20/Mw20) of the abundance ratio Mw20 of the intermediate phase in the endpoint detection window to the abundance ratio Mp20 of the intermediate phase in the polishing layer at 20° C. is 0.7 to 1.5.
17. The polishing pad of claim 16.
The ratio (Mp80/Mw80) of the abundance ratio Mw80 of the intermediate phase in the endpoint detection window to the abundance ratio Mp80 of the intermediate phase in the polishing layer at 80° C. is 0.5 to 1.5.
18. The polishing pad according to claim 16 or 17.
The difference (|Lp20−Lw20|) between the abundance ratio Lw20 and the abundance ratio Lp20 is 10 or less.
The polishing pad according to any one of claims 16-18.
The difference (|Sp80−Sw80|) between the abundance ratio Sw80 and the abundance ratio Sw80 is 15 or less.
The polishing pad according to any one of claims 16-19.
wherein the endpoint detection window comprises a polyurethane resin WI;
The polyurethane resin WI contains a structural unit derived from an aliphatic isocyanate,
The polishing pad according to any one of claims 16-20.
The polishing layer contains a polyurethane resin P,
The polyurethane resin P contains a structural unit derived from an aromatic isocyanate,
The polishing pad according to any one of claims 16-21.
The polishing layer contains hollow fine particles dispersed in the polishing layer,
The polishing pad according to any one of claims 16-22.
having a polishing layer and an endpoint detection window provided in an opening of the polishing layer;
In the dynamic viscoelasticity measurement performed under the conditions of tensile mode, frequency of 1.6 Hz, 30 to 55°C, and immersion, the storage elastic modulus E′w40 of the endpoint detection window at 40°C and the polishing layer at 40°C The ratio (E'p40/E'w40) to the storage modulus E'p40 is 0.70 to 3.00.
polishing pad.
In the dynamic viscoelasticity measurement, the ratio (E'p50/E'w50) of the storage elastic modulus E'w50 of the endpoint detection window at 50°C and the storage elastic modulus E'p50 of the polishing layer at 50°C is , from 0.70 to 5.00;
25. The polishing pad of claim 24.
In the dynamic viscoelasticity measurement, the difference between the loss coefficient tan δw30 of the endpoint detection window at 30° C. and the loss coefficient tan δp30 of the polishing layer at 30° C. (|tan δw30−tan δp30|) is 0.05 to 0.30. is
26. The polishing pad according to claim 24 or 25.
In the dynamic viscoelasticity measurement, the difference between the loss coefficient tan δw40 of the endpoint detection window at 40° C. and the loss coefficient tan δp40 of the polishing layer at 40° C. (|tan δw40−tan δp40|) is 0.05 to 0.40. is
The polishing pad according to any one of claims 24-26.
In the dynamic viscoelasticity measurement, the difference between the loss coefficient tan δw50 of the endpoint detection window at 50° C. and the loss coefficient tan δp50 of the polishing layer at 50° C. (|tan δw50−tan δp50|) is 0.05 to 0.50. is
The polishing pad according to any one of claims 24-27.
wherein the endpoint detection window comprises a polyurethane resin WI;
The polyurethane resin WI contains a structural unit derived from an aliphatic isocyanate,
The polishing pad according to any one of claims 24-28.
The polishing layer contains a polyurethane resin P,
The polyurethane resin P contains a structural unit derived from an aromatic isocyanate,
The polishing pad according to any one of claims 24-29.
The polishing layer contains hollow fine particles dispersed in the polishing layer,
The polishing pad according to any one of claims 24-30.
a polishing step of polishing an object to be polished using the polishing pad according to any one of claims 1 to 31 in the presence of a polishing slurry to obtain a polished object;
an endpoint detection step of performing endpoint detection by an optical endpoint detection method during the polishing;
A method for producing an abrasive article.