Manufacturing method of polishing pad and polishing workpiece

Abstract

A polishing pad having a polyurethane sheet as a polishing layer and a terminal point detection window provided at an opening of the polyurethane sheet, wherein in dynamic viscoelasticity measurement of the terminal point detection window under a tensile mode, a frequency of 1.0 Hz, and a temperature of 10 to 100°C, a storage elastic modulus E' of the terminal point detection window at 90°C is 1.0 x 104 Pa or more, a D hardness (D W90 ) of the terminal point detection window at 80°C is 40 or more, and a D hardness (D 7 ) of the terminal point detection window at 20°C is 40 to 90. W80 W20 ​​

Description

Technical Field

[0001] This invention relates to abrasive pads and a method for manufacturing abrasive workpieces using the same. Background Technology

[0002] In semiconductor manufacturing processes, chemical mechanical polishing (CMP) is used for planarization after insulating film deposition and for the formation of metal wiring. As a crucial technique in CMP, endpoint detection is essential for determining whether the polishing process is complete. For example, over-polishing or under-polishing relative to the target endpoint directly leads to product defects. Therefore, endpoint detection is necessary to strictly manage the polishing amount in CMP.

[0003] Chemical mechanical polishing (CMP) is a complex process. The polishing speed (polishing rate) varies due to the operating conditions of the polishing equipment, the quality of consumables (slurry, polishing pads, dressing machines, etc.), and deviations in the state over time during the polishing process. Furthermore, in recent years, the requirements for residual film thickness accuracy and in-plane uniformity in semiconductor manufacturing processes have become increasingly stringent. As a result, achieving sufficiently precise polishing endpoint detection has become even more challenging.

[0004] As the main methods for detecting the end point of grinding, there are known optical end point detection methods, torque end point detection methods, eddy current end point detection methods, etc. In the optical end point detection method, light is irradiated onto the wafer through a transparent window component set on the grinding pad, and the end point is detected by monitoring the reflected light.

[0005] As an example of an abrasive pad using such an optical endpoint detection method, Patent Document 1 discloses an abrasive pad for the purpose of providing a detection accuracy that can suppress slurry retention in the groove of a window component and improve the abrasive rate. In an abrasive pad having a pad body and a transparent window component integrally formed with a part of the pad body, the surface of the window component is made to be recessed from the surface of the pad body.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2002-001647 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] However, one method for manufacturing the window-shaped abrasive pad as described above involves filling a resin composition with the window component fixed in a mold, allowing it to cure, slicing the cured product, and then performing a finishing process. Here, since the window component and the cured resin composition are made of different materials, their physical properties differ considerably. For example, during slicing, the window portion may become dented or cracked. Furthermore, during the finishing process, due to differences in the amount of wear between the window portion and the abrasive layer, the window portion may also become dented.

[0011] If such depressions or indentations occur, slurry and grinding debris can easily accumulate there, causing scratches and potentially reducing the surface quality of the workpiece. Furthermore, if the wear on the window area is relatively small, as grinding continues, residue tends to remain on the window area more easily than the grinding layer, resulting in a convex shape. Such a convex window area can also cause scratches and reduce the surface quality of the workpiece.

[0012] The present invention was made in view of the above-mentioned problems. In the first and third embodiments, one of its objectives is to provide a polishing pad with excellent flatness for slicing and trimming processes and a method for manufacturing polished workpieces using the same.

[0013] Furthermore, if the characteristics of the polishing layer and the endpoint detection window are different, as in Patent Document 1, then, for example, the portion of the endpoint detection window may be polished faster than the polishing layer, becoming a depression. Slurry and polishing debris can easily accumulate there, sometimes resulting in defects (surface defects). Moreover, if the portion of the endpoint detection window is polished slower than the polishing layer, as polishing progresses, the endpoint detection window may become a protrusion, creating defects and potentially reducing the surface quality of the polished object.

[0014] The present invention was made in view of the above-mentioned problems. In the second and fourth embodiments, one of the objectives is to provide a method for manufacturing a grinding pad and a grinding workpiece using the same, which can produce a grinding workpiece with excellent surface quality and low defect rate even when an endpoint detection window is provided.

[0015] Methods for solving problems

[0016] [First Embodiment]

[0017] The inventors of this application conducted in-depth research to solve the aforementioned problems. As a result, they discovered that by giving the endpoint detection window a specified viscoelasticity and hardness, the problems could be solved, thus completing this invention.

[0018] That is, the first embodiment of the present invention is as follows.

[0019] [1]

[0020] An abrasive pad having an abrasive layer and an endpoint detection window provided in an opening of the abrasive layer.

[0021] In the dynamic viscoelasticity determination of the endpoint detection window conducted under tensile mode, frequency 1.0 Hz, and temperature range of 10–100 °C, the storage modulus E' at 90 °C was... W90 1.0×10 7 Pa or above

[0022] The D hardness (D) at 80°C of the endpoint detection window W80 (40 or above)

[0023] The D hardness (D) at 20°C of the endpoint detection window W20 The range is 40-90.

[0024] [2]

[0025] The abrasive pad as described in [1], wherein the endpoint detection window comprises polyurethane resin WI.

[0026] [3]

[0027] The abrasive pad as described in [2], wherein the polyurethane resin WI comprises structural units derived from alicyclic isocyanates and / or aliphatic isocyanates.

[0028] [4]

[0029] The abrasive pad as described in [2] or [3], wherein the polyurethane resin WI comprises structural units derived from compounds having three or more hydroxyl groups.

[0030] [5]

[0031] The abrasive pad as described in any one of [1] to [4], wherein, in the dynamic viscoelasticity measurement of the endpoint detection window, the storage modulus E' at 30°C is... W30 60×10 7 ~100×10 7 Pa.

[0032] [6]

[0033] The abrasive pad as described in any one of [1] to [5], wherein the peak temperature of tanδ in the dynamic viscoelasticity measurement of the endpoint detection window is 70 to 100 °C.

[0034] [7]

[0035] The abrasive pad as described in any one of [1] to [6], wherein the abrasive layer comprises polyurethane resin P and hollow microparticles dispersed in the polyurethane resin P.

[0036] [8]

[0037] A method for manufacturing a ground workpiece, comprising:

[0038] A grinding process in which a grinding pad, as described in any one of [1] to [7], is used to grind a workpiece in the presence of a grinding slurry to obtain a ground workpiece; and

[0039] The endpoint detection process in this grinding process uses an optical endpoint detection method to perform endpoint detection.

[0040] [Second Implementation]

[0041] The inventors of this application conducted in-depth research to solve the aforementioned problems. As a result, they discovered that by establishing a predetermined relationship between the viscoelasticity of the endpoint detection window and the abrasive layer, the aforementioned problems can be solved, thus completing this invention.

[0042] That is, the second embodiment of the present invention is as follows.

[0043] [1]

[0044] An abrasive pad having an abrasive layer and an endpoint detection window provided in an opening of the abrasive layer.

[0045] In the dynamic viscoelasticity determination conducted under tensile conditions, a frequency of 1.0 Hz, and a temperature range of 10–100°C, the storage modulus E' at 30°C within the endpoint detection window was determined. W30 The energy storage modulus E' of the polishing layer at 30°C P30 The ratio (E') P30 / E' W30 The value ranges from 0.60 to 1.50.

[0046] [2]

[0047] The abrasive pad as described in [1], wherein the endpoint detection window comprises polyurethane resin WI.

[0048] [3]

[0049] The abrasive pad as described in [2], wherein the polyurethane resin WI comprises structural units derived from alicyclic isocyanates and / or aliphatic isocyanates.

[0050] [4]

[0051] The abrasive pad as described in [2] or [3], wherein the polyurethane resin WI comprises structural units derived from compounds having three or more hydroxyl groups.

[0052] [5]

[0053] The abrasive pad as described in any one of [1] to [4], wherein, in the dynamic viscoelasticity measurement, the storage modulus E' at 50°C of the endpoint detection window is... W50 The energy storage modulus E' of the polishing layer at 50°C P50 The ratio (E') P50 / E' W50 The range is 0.70 to 2.00.

[0054] [6]

[0055] The abrasive pad as described in any one of [1] to [5], wherein, in the dynamic viscoelasticity measurement of the endpoint detection window, the storage modulus E' at 30°C is... W30 10×10 7 ~60×10 7 Pa.

[0056] [7]

[0057] The abrasive pad as described in any one of [1] to [6], wherein the D hardness (D) of the endpoint detection window at 20°C is... W20 The range is 40-70.

[0058] [8]

[0059] The abrasive pad as described in any one of [1] to [7], wherein the abrasive layer comprises polyurethane resin P and hollow microparticles dispersed in the polyurethane resin P.

[0060] [9]

[0061] A method for manufacturing a ground workpiece, comprising:

[0062] A grinding process in which an object is ground using the grinding pad according to any one of claims [1] to [8] in the presence of a grinding slurry; and

[0063] The endpoint detection process in this grinding process uses an optical endpoint detection method to perform endpoint detection.

[0064] [Third Implementation]

[0065] The inventors of this application conducted in-depth research to solve the aforementioned problems. As a result, they discovered that by establishing a predetermined relationship between the endpoint detection window and the polished layer in pulsed NMR analysis, the aforementioned problems can be solved, thus completing this invention.

[0066] That is, the third embodiment of the present invention is as follows.

[0067] [1]

[0068] An abrasive pad having an abrasive layer and an endpoint detection window provided in an opening of the abrasive layer.

[0069] When the free induction decay curves of 1H spin-spin relaxation obtained by pulsed NMR using the Solid Echo method are separated into three curves representing the three components—crystalline phase, mesophase, and amorphous phase—according to the order of relaxation time from shortest to longest,

[0070] At 20°C, the ratio of the amorphous phase presence ratio Lw20 in the endpoint detection window to the amorphous phase presence ratio Lp20 in the polishing layer (Lp20 / Lw20) is 0.5 to 2.0.

[0071] At 80°C, the ratio of the presence ratio of the crystalline phase Sw80 in the endpoint detection window to the presence ratio of the crystalline phase Sp80 in the polishing layer (Sp80 / Sw80) is 0.5 to 2.0.

[0072] [2]

[0073] The polishing pad as described in [1], wherein the ratio of the presence ratio of the intermediate phase Mw20 of the endpoint detection window to the presence ratio of the intermediate phase Mp20 of the polishing layer at 20°C (Mp20 / Mw20) is 0.7 to 1.5.

[0074] [3]

[0075] The polishing pad as described in [1] or [2], wherein the ratio of the presence ratio of the intermediate phase Mw80 of the endpoint detection window at 80°C to the presence ratio of the intermediate phase Mp80 of the polishing layer (Mp80 / Mw80) is 0.5 to 1.5.

[0076] [4]

[0077] The abrasive pad as described in any one of [1] to [3], wherein the difference between the presence ratio Lw20 and the presence ratio Lp20 (|Lp20-Lw20|) is 10 or less.

[0078] [5]

[0079] The abrasive pad as described in any one of [1] to [4], wherein the difference between the presence ratio Sw80 and the presence ratio Sp80 (|Sp80-Sw80|) is 15 or less.

[0080] [6]

[0081] The abrasive pad as described in any one of [1] to [5], wherein the endpoint detection window comprises polyurethane resin WI,

[0082] The polyurethane resin WI contains structural units derived from aliphatic isocyanates.

[0083] [7]

[0084] The abrasive pad as described in any one of [1] to [6], wherein the abrasive layer comprises polyurethane resin P,

[0085] The polyurethane resin P contains structural units derived from aromatic isocyanates.

[0086] [8]

[0087] The abrasive pad as described in any one of [1] to [7], wherein the abrasive layer comprises hollow microparticles dispersed in the abrasive layer.

[0088] [9]

[0089] A method for manufacturing a ground workpiece, comprising:

[0090] A grinding process in which a grinding pad, as described in any one of [1] to [8], is used to grind a workpiece in the presence of a grinding slurry to obtain a ground workpiece; and

[0091] The endpoint detection process in this grinding process uses an optical endpoint detection method to perform endpoint detection.

[0092] [Fourth Implementation]

[0093] The inventors of this application conducted in-depth research to solve the aforementioned problems. As a result, they discovered that by establishing a predetermined relationship between the viscoelasticity of the endpoint detection window and the abrasive layer, the aforementioned problems can be solved, thus completing this invention.

[0094] That is, the fourth embodiment of the present invention is as follows.

[0095] [1]

[0096] An abrasive pad having an abrasive layer and an endpoint detection window provided in an opening of the abrasive layer.

[0097] In the dynamic viscoelasticity test conducted under the conditions of tensile mode, frequency 1.6 Hz, 30–55 °C and immersion, the ratio of the storage modulus E'w40 of the endpoint detection window at 40 °C to the storage modulus E'p40 of the abrasive layer at 40 °C (E'p40 / E'w40) was 0.70–3.00.

[0098] [2]

[0099] The abrasive pad as described in [1], wherein, in the dynamic viscoelasticity test, the ratio (E'p50 / E'w50) of the storage modulus E'w50 of the endpoint detection window at 50°C to the storage modulus E'p50 of the abrasive layer at 50°C is 0.70 to 5.00.

[0100] [3]

[0101] The abrasive pad as described in [1] or [2], wherein, in the dynamic viscoelasticity measurement, the difference between the loss factor tanδw30 of the endpoint detection window at 30°C and the loss factor tanδp30 of the abrasive layer at 30°C (|tanδw30-tanδp30|) is 0.05 to 0.30.

[0102] [4]

[0103] The abrasive pad as described in any one of [1] to [3], wherein, in the dynamic viscoelasticity measurement, the difference between the loss factor tanδw40 of the endpoint detection window at 40°C and the loss factor tanδp40 of the abrasive layer at 40°C (|tanδw40-tanδp40) is 0.05 to 0.40.

[0104] [5]

[0105] The abrasive pad as described in any one of [1] to [4], wherein, in the dynamic viscoelasticity measurement, the difference (|tanδw50-tanδp50|) between the loss factor tanδw50 of the endpoint detection window at 50°C and the loss factor tanδp50 of the abrasive layer at 50°C is 0.05 to 0.50.

[0106] [6]

[0107] The abrasive pad as described in any one of [1] to [5], wherein the endpoint detection window comprises polyurethane resin WI,

[0108] The polyurethane resin WI contains structural units derived from aliphatic isocyanates.

[0109] [7]

[0110] The abrasive pad as described in any one of [1] to [6], wherein the abrasive layer comprises polyurethane resin P,

[0111] The polyurethane resin P contains structural units derived from aromatic isocyanates.

[0112] [8]

[0113] The abrasive pad as described in any one of [1] to [7], wherein the abrasive layer comprises hollow microparticles dispersed in the abrasive layer.

[0114] [9]

[0115] A method for manufacturing a ground workpiece, comprising:

[0116] A grinding process in which a grinding pad, as described in any one of [1] to [8], is used to grind a workpiece in the presence of a grinding slurry to obtain a ground workpiece; and

[0117] The endpoint detection process in this grinding process uses an optical endpoint detection method to perform endpoint detection.

[0118] Invention Effects

[0119] According to the first and third embodiments of the present invention, an abrasive pad with excellent flatness during slicing and trimming processes and a method for manufacturing abrasive workpieces using the same can be provided.

[0120] Furthermore, according to the second and fourth embodiments of the present invention, a method for manufacturing a grinding pad and a grinding workpiece using the same can be provided, which can produce a grinding workpiece that is not prone to defects and has excellent surface quality even when an endpoint detection window is present. Attached Figure Description

[0121] [ Figure 1 [This is a schematic perspective view of the abrasive pad according to the first to fourth embodiments.]

[0122] [ Figure 2 [This is a schematic cross-sectional view of the endpoint detection window portion of the abrasive pad in the first to fourth embodiments.]

[0123] [ Figure 3 [This is a schematic cross-sectional view of the endpoint detection window portion of the abrasive pad in embodiments 1 to 4, in another manner.]

[0124] [ Figure 4 [Illustration] is a schematic diagram showing the film thickness control system mounted on a CMP.

[0125] [ Figure 5A [Image] is a diagram showing the surface condition of the end detection window portion of the abrasive pad in Example A1 before trimming after slicing.

[0126] [ Figure 5B [Image] is a diagram showing the surface condition of the end detection window portion of the abrasive pad of Comparative Example A1 before trimming after slicing.

[0127] [ Figure 5C [Image] is a graph showing the surface condition of the end detection window portion of the abrasive pad of Comparative Example A2 before trimming after slicing.

[0128] [ Figure 5D [Image] is a diagram showing the surface condition of the end detection window portion of the abrasive pad in Example A2 before trimming after slicing.

[0129] [ Figure 6A [Illustration] is a diagram showing the surface condition of the end detection window portion of the polishing pad of Example A1 after modification.

[0130] [ Figure 6B[Image] is a diagram showing the surface condition of the end detection window portion of the polishing pad of Comparative Example A1 after the polishing process.

[0131] [ Figure 6C [Image 1] is a diagram showing the surface condition of the end detection window portion of the polishing pad of Comparative Example A2 after it has been repaired.

[0132] [ Figure 6D [Image] is a diagram showing the surface condition of the endpoint detection window portion of the polishing pad of Example A2 after modification.

[0133] [ Figure 7A [Image] is a diagram showing the surface condition of the end detection window portion of the abrasive pad of Example C1 before trimming after slicing.

[0134] [ Figure 7B [Image] is a diagram showing the surface condition of the end detection window portion of the abrasive pad of Example C2 before trimming after slicing.

[0135] [ Figure 7C [Image] is a graph showing the surface condition of the end detection window portion of the abrasive pad of Comparative Example C1 before trimming after slicing.

[0136] [ Figure 8A [Illustration] is a diagram showing the surface condition of the end detection window portion of the polishing pad of embodiment C1 after modification.

[0137] [ Figure 8B [Illustration] is a diagram showing the surface condition of the endpoint detection window portion of the polishing pad of the modified embodiment C2.

[0138] [ Figure 8C [Image 1] is a diagram showing the surface condition of the end detection window portion of the polishing pad of Comparative Example C1 after the polishing process. Detailed Implementation

[0139] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited thereto, and various modifications can be made without departing from its spirit. Furthermore, in the drawings, the same symbols are used to denote the same elements, and repeated descriptions are omitted. In addition, unless otherwise specified, positional relationships such as up, down, left, and right are based on the positional relationships shown in the drawings. Moreover, the scale of the drawings is not limited to the scale shown in the illustrations.

[0140] 1. First Implementation Method

[0141] 1.1. Grinding pad

[0142] The abrasive pad of the first embodiment has an abrasive layer and an endpoint detection window provided in the opening of the abrasive layer. In the dynamic viscoelasticity measurement of the endpoint detection window under tensile mode, frequency 1.0 Hz, and temperature 10–100°C, the storage modulus E' at 90°C is...W90 1.0×10 7 Pa or higher, the D hardness at 80°C of the endpoint test window (D W80 The hardness (D) of the endpoint test window at 20°C is above 40. W20 The range is 40-70.

[0143] Therefore, from the viewpoint that protrusions are less likely to be generated during slicing, flatness can be improved; and from the viewpoint that the polishing layer is less likely to be over-polished compared to the endpoint detection window during finishing, flatness can be improved. It should be noted that, in the first embodiment, these two types of flatness are collectively referred to as "flatness".

[0144] Figure 1 A schematic perspective view of the abrasive pad according to the first embodiment is shown. Figure 1 As shown, the abrasive pad 10 of the first embodiment has an abrasive layer 11 and an endpoint detection window 12. If necessary, a buffer layer 13 may also be provided on the side opposite to the abrasive surface 11a.

[0145] Figures 2-3 Show Figure 1 A cross-sectional view of the periphery of the endpoint detection window 12. (See also...) Figures 2-3 As shown, an adhesive layer 14 can also be provided between the grinding layer 11 and the buffer layer 13. Alternatively, an adhesive layer 14 can be provided on the surface of the buffer layer 13 for bonding with the ground layer 11. Figure 4 The adhesive layer 15 is attached to the workbench 22. The abrasive surface 11a of the abrasive pad in the first embodiment, in addition to... Figure 2 Besides the flat scenario shown, it can also be as follows: Figure 3 The diagram shows a concave-convex shape with grooves 16. Grooves 16 can also be formed individually or in combination to form multiple grooves of various shapes such as concentric circles, grids, and radial patterns.

[0146] 1.1.1. Endpoint Detection Window

[0147] The endpoint detection window is a transparent component with an opening in the polished layer, which serves as a light transmission path from the film thickness sensor in optical endpoint detection. In the first embodiment, the endpoint detection window is circular, but it can also be square, rectangular, polygonal, elliptical, or other shapes as needed.

[0148] In the first embodiment, during the manufacturing of the polishing pad, when slicing is performed, the endpoint detection window is prevented from becoming concave or cracked compared to the polishing layer, and the endpoint detection window is prevented from becoming concave or protruding compared to the polishing layer during the finishing process, thereby improving flatness. From this point of view, the storage modulus E' and hardness D of the endpoint detection window are specified.

[0149] 1.1.1.1. Dynamic viscoelasticity

[0150] The storage modulus E' of the endpoint detection window in the first embodiment can be determined by dynamic viscoelasticity measurement performed under tensile conditions, a frequency of 1.0 Hz, and a temperature range of 10–100°C. As will be described later, the object is sliced ​​while heated; therefore, the storage modulus E' of the endpoint detection window in the first embodiment is defined as the storage modulus E' at 90°C. W90 Furthermore, in the first embodiment, the peak temperature position of the loss tangent tanδ can be further adjusted so that the loss modulus E'' (viscous component) is dominant relative to the storage modulus E' (elastic component) during slicing. From the viewpoint of showing the characteristics of the end-point detection window during trimming, the storage modulus E' at 30°C can also be specified. W30 .

[0151] Storage modulus E' at 90°C of the endpoint detection window W90 1.0×10 7 Pa or higher, preferably 1.25 × 10 Pa. 7 ~20×10 7 Pa, more preferably 1.5 × 10 Pa 7 ~10×10 7 Pa. By making the energy storage modulus E' W90 1.0×10 7 With a strength of Pa or higher, when slicing is performed, it can suppress the endpoint detection window from becoming concave or protruding compared to the polished layer, suppress cracking, and further improve flatness.

[0152] Furthermore, in the dynamic viscoelasticity measurement of the endpoint detection window, the peak temperature of tanδ is preferably 70–100°C, more preferably 70–95°C, and even more preferably 75–90°C. By keeping the peak temperature of tanδ within the above range, during slicing, it is possible to suppress the endpoint detection window from becoming concave or protruding compared to the polishing layer, thereby suppressing cracking and further improving flatness.

[0153] Furthermore, the energy storage modulus E' at 30°C W30 Preferably 10×10 7 ~80×10 7 Pa, more preferably 20 × 10 Pa 7 ~70×10 7 Pa, more preferably 30 × 10 Pa 7 ~70×10 7 Pa. By making the energy storage modulus E' W30 Within the aforementioned range, during the finishing process, it is possible to prevent the endpoint detection window from becoming recessed compared to the polished layer, thereby further improving flatness.

[0154] There are no particular restrictions on the testing conditions for dynamic viscoelasticity; the testing can be performed using the conditions described in the examples.

[0155] 1.1.1.2. D Hardness

[0156] The D hardness (D) at 80°C at the endpoint test window W80 The hardness of D is 40 or higher, preferably 40 to 60, and more preferably 40 to 50. This is achieved by making the D hardness (D...)... W80 With a value of 40 or higher, when slicing is performed, it can suppress the endpoint detection window from becoming a concave or protruding state compared to the polished layer, suppress cracking, and further improve flatness.

[0157] Additionally, the D hardness (D) at 20°C of the endpoint detection window. W20 The hardness of D is 40-90, preferably 50-85, and more preferably 55-80. This is achieved by making the D hardness (D...)... W20 Within the above range, during the finishing process, it is possible to prevent the endpoint detection window from becoming more concave or protruding than the polished layer, thereby further improving flatness.

[0158] There are no particular restrictions on the conditions for measuring D hardness; it can be measured using the conditions described in the examples.

[0159] 1.1.1.3. Constituent Materials

[0160] The material constituting the endpoint detection window can be any transparent component capable of functioning as a window, without particular limitations. Examples include polyurethane resin WI, polyvinyl chloride resin, polyvinylidene fluoride resin, polyethersulfone resin, polystyrene resin, polyethylene resin, and polytetrafluoroethylene resin. Among these, polyurethane resin WI is preferred. By using such a resin, it is easier to adjust the aforementioned dynamic viscoelastic properties, D-hardness, and transparency, and flatness can be further improved.

[0161] Polyurethane resin WI can be synthesized from polyisocyanates and polyols, containing structural units from polyisocyanates and structural units from polyols.

[0162] 1.1.1.3.1. Structural units derived from polyisocyanates

[0163] The structural units derived from polyisocyanates are not particularly limited; examples include structural units derived from alicyclic isocyanates, aliphatic isocyanates, and aromatic isocyanates. The polyurethane resin WI preferably contains structural units derived from alicyclic and / or aliphatic isocyanates. This facilitates the understanding of dynamic viscoelastic properties and D-hardness (D...). W20 ) and D hardness (D W80Adjusting the window to the aforementioned range not only further improves transparency but also tends to further enhance its resistance to yellowing. Additionally, it can further improve flatness.

[0164] As an alicyclic isocyanate, there are no particular limitations; examples include 4,4'-methylene-bis(cyclohexyl isocyanate) (hydrogenated MDI), cyclohexyl-1,2-diisocyanate, cyclohexyl-1,4-diisocyanate, isophorone diisocyanate, etc.

[0165] As an aliphatic isocyanate, there are no particular limitations. Examples include hexamethylene diisocyanate (HDI), pentamethylene diisocyanate (PDI), tetramethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, trimethylene diisocyanate, and trimethylhexamethylene diisocyanate.

[0166] As an aromatic isocyanate, there is no particular limitation, for example, phenyl diisocyanate, 2,6-toluene diisocyanate (2,6-TDI), 2,4-toluene diisocyanate (2,4-TDI), xylene diisocyanate, naphthalene diisocyanate, and diphenylmethane-4,4'-diisocyanate (MDI).

[0167] 1.1.1.3.2. Structural units derived from polyols

[0168] As a structural unit derived from polyols, there are no particular limitations; for example, low molecular weight polyols with a molecular weight of less than 300 and high molecular weight polyols with a molecular weight of more than 300 can be cited.

[0169] As low molecular weight polyols, there are no particular limitations. Examples include ethylene glycol, propylene glycol, diethylene glycol, triethylene glycol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,5-pentanediol, neopentanediol, 1,6-hexanediol, 2,5-hexanediol, dipropylene glycol, 2,2,4-trimethyl-1,3-pentanediol, tricyclodecanediethanol, and 1,4-cyclohexanediethanol, which are low molecular weight polyols with two hydroxyl groups; and glycerol, glycerol, trimethylolpropane, isocyanuric acid, and erythritol, which are low molecular weight polyols with three or more hydroxyl groups. Low molecular weight polyols can be used alone or in combination of two or more.

[0170] Among them, low-molecular-weight polyols with three or more hydroxyl groups are preferred, and glycerol is more preferred. By using such low-molecular-weight polyols, the dynamic viscoelastic properties and D-hardness can be easily adjusted to the above-mentioned range, the amount of wear can be adjusted, and the flatness can be further improved. In addition to further improving transparency, there is also a trend of further improving the window's resistance to yellowing.

[0171] The content of structural units from low-molecular-weight polyols having three or more hydroxyl groups is preferably 8.0 to 30 parts, more preferably 10 to 25 parts, and even more preferably 12.5 to 20 parts, relative to 100 parts of structural units from polyisocyanates. By keeping the content of structural units from low-molecular-weight polyols having three or more hydroxyl groups within the above range, the dynamic viscoelastic properties and D-hardness can be easily adjusted to the above range, and the flatness can be further improved. In addition to further improving transparency, there is also a tendency for further improvement in the window's resistance to yellowing.

[0172] Furthermore, there are no particular limitations on the term "high molecular weight polyol," and examples include polyether polyols, polyester polyols, polycarbonate polyols, polyether polycarbonate polyols, polyurethane polyols, epoxy polyols, vegetable oil polyols, polyolefin polyols, acrylic polyols, and vinyl monomer-modified polyols. A single high molecular weight polyol can be used, or two or more can be used in combination.

[0173] Furthermore, the number average molecular weight of the polymeric polyol is preferably 300–1200, more preferably 400–950, and even more preferably 500–800. By using such a polymeric polyol, it is easier to adjust the dynamic viscoelastic properties and D-hardness to the above-mentioned ranges.

[0174] Among them, polyether polyols are preferred, and polytetramethylene ether glycol is more preferred. By using such high-molecular-weight polyols, the dynamic viscoelastic properties and D-hardness can be easily adjusted to the above-mentioned ranges, the hardness at low temperatures can be easily adjusted, and the decrease in hardness with increasing temperature can be suppressed. In addition, besides further improving flatness and transparency, there is also a tendency to further improve the window's resistance to yellowing.

[0175] The content of structural units from polyether polyol is preferably 40 to 100 parts, more preferably 50 to 90 parts, and more preferably 60 to 84 parts, relative to 100 parts of structural units from polyisocyanate. By keeping the content of structural units from polyether polyol within the above range, the dynamic viscoelastic properties and D-hardness can be easily adjusted to the above range, and the flatness can be further improved. In addition to further improving transparency, there is also a trend of further improving the window's resistance to yellowing.

[0176] Furthermore, as the polyol, it is preferable to use a combination of low-molecular-weight polyols and high-molecular-weight polyols, and more preferably, a combination of low-molecular-weight polyols having three or more hydroxyl groups and polyether polyols. This makes it easier to adjust the dynamic viscoelastic properties and D-hardness to the aforementioned ranges, easier to adjust the hardness at low temperatures, and able to suppress the decrease in hardness with increasing temperature. In addition to further improving flatness and transparency, it also tends to further improve the window's resistance to yellowing.

[0177] Based on the above viewpoint, the content of polyether polyol is preferably 1.0 to 9.0 parts, more preferably 2.0 to 8.0 parts, and even more preferably 3.0 to 7.0 parts, relative to 1 part of low molecular weight polyol having 3 or more hydroxyl groups.

[0178] 1.1.2. Abrasive Layer

[0179] The polishing layer of the first embodiment has an opening for embedding an end-point detection window. The location of the opening is not particularly limited, but it is preferably located in a radial direction corresponding to the film thickness detection sensor 23 provided on the worktable 22. Furthermore, the number of openings is not particularly limited, but it is preferable to have multiple openings at the same radial direction, so that the window passes over the film thickness detection sensor 23 multiple times as the polishing pad 10 adhered to the worktable 22 rotates one revolution.

[0180] There are no particular limitations on the type of abrasive layer, for example, a resin-foamed molded body, a non-foamed molded body, or a resin-impregnated substrate containing resin in a fiber substrate.

[0181] Here, a resin-foamed molded body refers to a foamed body made of a specified resin without a fibrous substrate. There are no particular limitations on the shape of the foam; examples include spherical bubbles, roughly spherical bubbles, teardrop-shaped bubbles, or continuous bubbles formed by partial connections between individual bubbles.

[0182] Furthermore, a non-foamed resin molded article refers to a non-foamed body composed of a specified resin without a fibrous substrate. A non-foamed body refers to a substance that does not have the air bubbles described above. In the first embodiment, substances formed by attaching a curable composition to a substrate such as a film and then curing it are also included in the non-foamed resin molded article. More specifically, resin cured products formed by gravure coating, small-diameter gravure coating, reverse roller coating, transfer roller coating, kiss-type coating, die coating, screen printing, spraying, etc., are also included in the non-foamed resin molded article.

[0183] Furthermore, resin-impregnated substrate refers to a substrate obtained by impregnating a fiber substrate with resin. Here, there are no particular limitations on the fiber substrate; examples include woven fabrics, nonwoven fabrics, and knitted fabrics.

[0184] 1.1.2.1. Dynamic viscoelasticity

[0185] For the polishing layer, in addition to the polishing rate and the surface quality of the workpiece, from the viewpoint of preventing the endpoint detection window in the polishing pad obtained by slicing and trimming from becoming a state of depression or cracking compared to the polishing layer, it is preferable to have specified dynamic viscoelastic properties.

[0186] Specifically, in the dynamic viscoelasticity measurement conducted under tensile conditions, a frequency of 1.0 Hz, and a temperature range of 10–100°C, the storage modulus E' of the polished layer at 90°C was determined. P90 Preferably 1.0×10 7 Pa or higher, preferably 2.0 × 10 Pa. 7 ~20×10 7 Pa, more preferably 3.0 × 10 Pa 7 Pa ~ 15 × 10 7 Pa. By making the energy storage modulus E' P90 1.0×10 7 In addition to improvements in grinding rate and surface quality of the workpiece, the end-point detection window of the grinding pad obtained by slicing and trimming further suppresses the presence of depressions, protrusions, and cracks in the grinding layer, and tends to further improve flatness.

[0187] Furthermore, from the same perspective, the energy storage modulus E' W90 With energy storage modulus E' P90 The difference (E') P90 -E' W90 The value is 9.5 × 10 7 Pa below, preferably 1.0 × 10 Pa 7 Pa ~ 9.0 × 10 7 Pa, more preferably 2.0 × 10 Pa 7 Pa ~ 9.0 × 10 7 Pa. By making the difference (E') P90 -E' W90 The value is 9.5 × 10 7 Below Pa, under slicing conditions, the difference in physical properties between the grinding layer and the endpoint detection window becomes smaller, thus the grinding layer and the endpoint detection window are sliced ​​uniformly, and the shape of the window easily becomes flat. Therefore, in the grinding pad obtained by slicing and trimming, the endpoint detection window becomes more suppressed than the state of the grinding layer being concave, protruding, or broken, and there is a tendency to further improve the flatness.

[0188] 1.1.2.2. Polyurethane Sheets

[0189] The following example illustrates a polyurethane sheet as an example of a polishing layer. However, the polishing layer is not limited to polyurethane sheets; any resin sheet can be used.

[0190] There are no particular limitations on the polyurethane resin P used to constitute the polyurethane sheet; examples include polyester-based polyurethane resins, polyether-based polyurethane resins, and polycarbonate-based polyurethane resins. One type may be used alone, or in combination of two or more types.

[0191] Polyurethane resin P can be synthesized from polyisocyanates and polyols, with a reaction mixture of urethane prepolymer and curing agent being particularly preferred. Here, the urethane prepolymer can be synthesized from polyisocyanates and polyols. The polyisocyanates, polyols, and curing agents constituting polyurethane resin P are described below.

[0192] 1.1.2.2.1. Structural units derived from polyisocyanates

[0193] The structural unit derived from the polyisocyanate is not particularly limited; for example, structural units derived from alicyclic isocyanates, aliphatic isocyanates, and aromatic isocyanates can be cited. Among these, aromatic isocyanates are preferred, and 2,4-toluene diisocyanate (2,4-TDI) is more preferred.

[0194] As alicyclic isocyanates, aliphatic isocyanates, and aromatic isocyanates, the same substances as those exemplified in the above endpoint detection window can be shown.

[0195] 1.1.2.2.2. Structural units derived from polyols

[0196] The structural unit derived from polyols is not particularly limited; examples include low-molecular-weight polyols with a molecular weight less than 300 and high-molecular-weight polyols with a molecular weight of 300 or more. Preferably, at least a low-molecular-weight polyol is used, and more preferably, both low-molecular-weight and high-molecular-weight polyols are used.

[0197] Examples of low-molecular-weight and high-molecular-weight polyols can be the same substances as those illustrated in the endpoint detection window described above. Among these, low-molecular-weight polyols with two hydroxyl groups are preferred, and diethylene glycol is more preferred. Furthermore, high-molecular-weight polyols are preferred, and polyether polyols are more preferred.

[0198] 1.1.2.2.3. Curing agent

[0199] There are no particular limitations on the type of curing agent; examples include polyamines and polyols. A single curing agent can be used, or two or more can be used in combination.

[0200] There are no particular limitations on the term "polyamine". Examples include aliphatic polyamines such as ethylenediamine, propylenediamine, and hexamethylenediamine; alicyclic polyamines such as isophorone diamine and dicyclohexylmethane-4,4'-diamine; and aromatic polyamines such as 3,3'-dichloro-4,4'-diaminodiphenylmethane (MOCA), 4-methyl-2,6-bis(methylthio)-1,3-phenylenediamine, 2-methyl-4,6-bis(methylthio)-1,3-phenylenediamine, and 2,2-bis(3-amino-4-hydroxyphenyl)propane.

[0201] Among them, aromatic polyamines are preferred, and 3'-dichloro-4,4'-diaminodiphenylmethane (MOCA) is more preferred.

[0202] As a polyol, the same polyol as that exemplified in the above-described endpoint detection window may be used. Among these, high molecular weight polyols are preferred, polyether polyols are more preferred, and polypropylene glycol is even more preferred.

[0203] 1.1.2.2.4. Hollow microparticles

[0204] The aforementioned polyurethane sheet is preferably a foamed polyurethane sheet comprising polyurethane resin P and hollow microparticles dispersed in the polyurethane resin P. Such a polyurethane sheet has independent air bubbles from the hollow microparticles and tends to easily adjust the aforementioned dynamic viscoelastic properties and D-hardness to the aforementioned range.

[0205] Hollow microparticles can be commercially available or synthesized using conventional methods. There are no particular restrictions on the material used as the outer shell of the hollow microparticles; examples include polyvinyl alcohol, polyvinylpyrrolidone, poly(meth)acrylic acid, polyacrylamide, polyethylene glycol, polyhydroxy ether acrylate, maleic acid copolymer, polyethylene oxide, polyurethane, acrylonitrile-vinylidene chloride copolymer, acrylonitrile-methyl methacrylate copolymer, and vinyl chloride-ethylene copolymer.

[0206] The shape of the hollow microparticles is not particularly limited; for example, they can be spherical or roughly spherical. Furthermore, when the hollow microparticles are inflatable balloons, they can be used in an uninflated state or in an inflated state.

[0207] The average particle size of the hollow microparticles contained in the polyurethane sheet is preferably 5 to 200 μm, more preferably 5 to 80 μm, even more preferably 5 to 50 μm, and particularly preferably 5 to 35 μm. By keeping the average particle size within the above range, it is easier to adjust the dynamic viscoelastic properties and D-hardness to within the above range. In addition, the average particle size can be measured by a laser diffraction particle size distribution measuring device (e.g., Spectris (Co., Ltd.), Mastersizer-2000).

[0208] 1.1.3. Other

[0209] The polishing pad of the first embodiment may have a buffer layer on the side of the polishing layer opposite to the polishing surface, or it may have an adhesive layer between the polishing layer and the buffer layer, on the non-polishing side of the buffer layer (the side that fits against the polishing machine). In this case, the buffer layer and the adhesive layer have openings at the same location as the end-point detection window of the polishing layer.

[0210] 2. Second Implementation Method

[0211] 2.1. Grinding pad

[0212] The abrasive pad of the second embodiment has an abrasive layer and an endpoint detection window provided in the opening of the abrasive layer. In a dynamic viscoelasticity measurement performed under tensile conditions, a frequency of 1.0 Hz, and a temperature range of 10–100°C, the storage modulus E' of the endpoint detection window at 30°C is... W30 The energy storage modulus E' of the polishing layer at 30°C P30 The ratio (E') P30 / E' W30 The value ranges from 0.60 to 1.50.

[0213] Therefore, during grinding, the dynamic viscoelastic properties of the grinding layer and the endpoint detection window become closer, thus further suppressing the generation of defects (surface defects) on the surface of the workpiece even when the endpoint detection window, which is a dissimilar component, is embedded in the grinding layer. As a result, a workpiece with excellent surface quality can be obtained.

[0214] Figure 1 A schematic perspective view of the abrasive pad according to the second embodiment is shown. Figure 1 As shown, the abrasive pad 10 of the second embodiment has an abrasive layer 11 and an endpoint detection window 12. If necessary, a buffer layer 13 may also be provided on the side opposite to the abrasive surface 11a.

[0215] Figures 2-3 Show Figure 1 A cross-sectional view of the periphery of the endpoint detection window 12. (See also...) Figures 2-3 As shown, an adhesive layer 14 can also be provided between the grinding layer 11 and the buffer layer 13. Alternatively, an adhesive layer 14 can be provided on the surface of the buffer layer 13 for bonding with the ground layer 11. Figure 4 The adhesive layer 15 is attached to the workbench 22. The abrasive surface 11a of the abrasive pad in the second embodiment, in addition to... Figure 2 Besides the flat scenario shown, it can also be as follows: Figure 3 The diagram shows a concave-convex shape with grooves 16. Grooves 16 can also be formed individually or in combination to form multiple grooves of various shapes such as concentric circles, grids, and radial patterns.

[0216] 2.1.1. Endpoint Detection Window

[0217] The endpoint detection window is a transparent component located at the opening of the polished layer, serving as a light transmission path from the film thickness sensor in optical endpoint detection. In the second embodiment, the endpoint detection window is circular, but it can also be square, rectangular, polygonal, elliptical, or other shapes as needed.

[0218] In the second embodiment, the ratio of the energy storage modulus E' of the endpoint detection window and the wear degree of the grinding layer during grinding is specified from the viewpoint of preventing either the endpoint detection window or the grinding layer from being over-ground and causing defects (surface defects) on the non-grinding material.

[0219] 2.1.1.1. Dynamic viscoelasticity

[0220] In the second embodiment, the storage modulus E' of the endpoint detection window and the polishing layer can be determined by dynamic viscoelasticity measurement performed under tensile conditions, a frequency of 1.0 Hz, and a temperature range of 10–100°C. In the second embodiment, from the viewpoint of showing the characteristics of the endpoint detection window and the polishing layer during polishing, the ratio of the storage modulus E' at 30°C is specified.

[0221] Storage modulus E' at 30°C at the endpoint detection window W30 Storage modulus E' of the polished layer at 30°C P30 The ratio (E') P30 / E' W30 The ratio (E') is 0.60 to 1.50, preferably 0.60 to 1.35, and more preferably 0.60 to 1.20. This is achieved by making the ratio (E')... P30 / E' W30 Within the above range, the characteristics of the endpoint detection window and the grinding layer are similar, thus further improving the surface quality of the workpiece.

[0222] Furthermore, from the same perspective, in dynamic viscoelasticity measurements, the storage modulus E' at 50°C of the endpoint detection window is... W50 Storage modulus E' of the polished layer at 50°C P50 The ratio (E') P50 / E' W50 The ratio (E') is preferably 0.70 to 2.00, more preferably 0.70 to 1.85, and even more preferably 0.70 to 1.70. This is achieved by adjusting the ratio (E') P50 / E' W50 Within the aforementioned range, the characteristics of the endpoint detection window and the grinding layer are similar, thus there is a tendency to further improve the surface quality of the workpiece being ground.

[0223] In the dynamic viscoelasticity determination at the endpoint detection window, the storage modulus E' at 30℃ W30 Preferably 10×10 7 ~60×10 7 Pa, more preferably 15 × 10 Pa 7 ~55×10 7 Pa, more preferably 20 × 10 7 ~50×10 7 Pa. By making the energy storage modulus E'W30 Within the aforementioned range, there is a trend towards further improvement in the surface quality of the workpiece being ground.

[0224] There are no particular restrictions on the testing conditions for dynamic viscoelasticity; the testing can be performed using the conditions described in the examples.

[0225] 2.1.1.2.D Hardness

[0226] D hardness (D) at 20°C at the endpoint test window W20 The hardness of D is 40-70, preferably 45-70, and more preferably 50-65. This is achieved by making the D hardness (D...)... W20 Within the aforementioned range, there is a tendency to further suppress the generation of defects (surface defects).

[0227] There are no particular restrictions on the conditions for measuring D hardness; it can be measured using the conditions described in the examples.

[0228] 2.1.1.3. Constituent Materials

[0229] The material constituting the endpoint detection window can be any transparent component capable of functioning as a window; there are no particular limitations. Examples include polyurethane resin WI, polyvinyl chloride resin, polyvinylidene fluoride resin, polyethersulfone resin, polystyrene resin, polyethylene resin, and polytetrafluoroethylene resin. Among these, polyurethane resin WI is preferred. By using such a resin, it is easier to adjust the aforementioned dynamic viscoelastic properties, D-hardness, and transparency.

[0230] Polyurethane resin WI can be synthesized from polyisocyanates and polyols, containing structural units from polyisocyanates and structural units from polyols.

[0231] 2.1.1.3.1. Structural units derived from polyisocyanates

[0232] The structural units derived from polyisocyanates are not particularly limited; for example, structural units derived from alicyclic isocyanates, aliphatic isocyanates, and aromatic isocyanates can be cited. The polyurethane resin WI preferably contains structural units derived from alicyclic and / or aliphatic isocyanates. This makes it easier to adjust the dynamic viscoelastic properties and D-hardness to the aforementioned ranges, resulting in further improvements in transparency and resistance to yellowing of the window.

[0233] There are no particular limitations on whether the isocyanate is alicyclic, aliphatic, or aromatic; for example, the compounds exemplified in the first embodiment can be cited.

[0234] 2.1.1.3.2. Structural units derived from polyols

[0235] As a structural unit derived from polyols, there are no particular limitations; for example, low molecular weight polyols with a molecular weight of less than 300 and high molecular weight polyols with a molecular weight of more than 300 can be cited.

[0236] There are no particular limitations on the low molecular weight polyols; for example, the compounds exemplified in the first embodiment can be cited.

[0237] Among them, low-molecular-weight polyols with three or more hydroxyl groups are preferred, and glycerol is more preferred. By using such low-molecular-weight polyols, the dynamic viscoelastic properties and D-hardness can be easily adjusted to the above-mentioned range, the amount of wear can be adjusted, and in addition to further improving transparency, there is also a trend of further improving the window's resistance to yellowing.

[0238] The content of structural units from low-molecular-weight polyols having three or more hydroxyl groups is preferably 7.5 to 30 parts, more preferably 10 to 25 parts, and even more preferably 12.5 to 20 parts, relative to 100 parts of structural units from polyisocyanates. By keeping the content of structural units from low-molecular-weight polyols having three or more hydroxyl groups within the above range, the dynamic viscoelastic properties and D-hardness can be easily adjusted to the above range, and in addition to further improving transparency, there is a tendency to further improve the window's resistance to yellowing.

[0239] Furthermore, there are no particular limitations on the high molecular weight polyol; for example, the compound exemplified in the first embodiment can be cited.

[0240] It should be noted that the number average molecular weight of the polymeric polyol is preferably 300–3000, more preferably 500–2500, and even more preferably 850–2000. By using such a polymeric polyol, it is easier to adjust the dynamic viscoelastic properties and D-hardness to the above range.

[0241] Among them, polyether polyols are preferred, and poly(oxytetramethylene) glycol is more preferred. By using such high-molecular-weight polyols, the dynamic viscoelastic properties and D-hardness can be easily adjusted to the above-mentioned range, the hardness at low temperatures can be easily adjusted, and the decrease in hardness with increasing temperature can be suppressed. In addition, besides further improvement in transparency, there is also a trend of further improvement in the window's resistance to yellowing.

[0242] The content of structural units from polyether polyols is preferably 80 to 200 parts, more preferably 85 to 160 parts, and even more preferably 90 to 140 parts, relative to 100 parts of structural units from polyisocyanate. By keeping the content of structural units from polyether polyols within the above range, the dynamic viscoelastic properties and D-hardness can be easily adjusted to the above range, and in addition to further improving transparency, there is also a tendency to further improve the window's resistance to yellowing.

[0243] Furthermore, as the polyol, it is preferable to use a combination of low-molecular-weight polyols and high-molecular-weight polyols, and more preferably, a combination of low-molecular-weight polyols having three or more hydroxyl groups and polyether polyols. This makes it easier to adjust the dynamic viscoelastic properties and D-hardness to the aforementioned ranges, resulting in further improvements in transparency and resistance to yellowing of the window.

[0244] Based on the above viewpoint, the content of polyether polyol is preferably 2.0 to 15.0 parts, more preferably 3.0 to 12.5 parts, and even more preferably 4.0 to 9.0 parts, relative to 1 part of low molecular weight polyol having 3 or more hydroxyl groups.

[0245] 2.1.2. Abrasive Layer

[0246] The polishing layer of the second embodiment has an opening for embedding an end-point detection window. The location of the opening is not particularly limited, but it is preferably located in a radial direction corresponding to the film thickness detection sensor 23 provided on the worktable 22. Furthermore, the number of openings is not particularly limited, but it is preferable to have multiple openings at the same radial direction so that the window passes over the film thickness detection sensor 23 multiple times as the polishing pad 10 adhered to the worktable 22 rotates one revolution.

[0247] There are no particular limitations on the type of abrasive layer, for example, a resin-foamed molded body, a non-foamed molded body, or a resin-impregnated substrate containing resin in a fiber substrate.

[0248] Here, regarding the foamed molded body, the non-foamed molded body, the resin impregnated substrate, and the fiber substrate, the methods described in the first embodiment can be cited, and therefore the description is omitted.

[0249] 2.1.2.1. Dynamic viscoelasticity

[0250] In the dynamic viscoelasticity determination of the polished layer, the storage modulus E' at 30℃ was measured. P30 Preferably 15×10 7 ~65×10 7 Pa, more preferably 20 × 10 Pa 7 ~60×10 7 Pa, more preferably 25 × 10 7 ~55×10 7 Pa. By making the energy storage modulus E' P30 Within the aforementioned range, there is a trend towards further improvement in the surface quality of the workpiece being ground.

[0251] In the dynamic viscoelasticity determination of the polished layer, the storage modulus E' at 50℃ was measured. P50 Preferably 10×10 7 ~40×10 7 Pa, more preferably 15 × 10 Pa7 ~35×10 7 Pa, more preferably 20 × 10 7 ~30×10 7 Pa. By making the energy storage modulus E' P50 Within the aforementioned range, there is a trend towards further improvement in the surface quality of the workpiece being ground.

[0252] 2.1.2.2. Polyurethane Sheets

[0253] The following example, as a polishing layer, illustrates a polyurethane sheet. Regarding the polyurethane sheet, the method described in the first embodiment can be cited, therefore, the description is omitted.

[0254] 2.1.3. Other

[0255] The polishing pad of the second embodiment may have a buffer layer on the side of the polishing layer opposite to the polishing surface, or it may have an adhesive layer between the polishing layer and the buffer layer, on the non-polishing side of the buffer layer (the side that fits against the polishing machine). In this case, the buffer layer and the adhesive layer have openings at the same location as the end-point detection window of the polishing layer.

[0256] 3. Third Implementation Method

[0257] 3.1. Grinding pad

[0258] The polishing pad of the third embodiment has a polishing layer and an endpoint detection window provided in the opening of the polishing layer. When the free induction decay curve of 1H spin-spin relaxation obtained by pulse NMR using the Solid Echo method is separated into three curves from three components—crystalline phase, mesophase, and amorphous phase—in order of relaxation time from shortest to longest, at 20°C, the ratio of the amorphous phase presence ratio Lw20 of the endpoint detection window to the amorphous phase presence ratio Lp20 of the polishing layer (Lp20 / Lw20) is 0.5 to 2.0, and at 80°C, the ratio of the crystalline phase presence ratio Sw80 of the endpoint detection window to the crystalline phase presence ratio Sp80 of the polishing layer (Sp80 / Sw80) is 0.5 to 2.0.

[0259] Therefore, from the viewpoint that protrusions are less likely to be generated during slicing, flatness can be improved; and from the viewpoint that the polishing layer is less likely to be over-polished compared to the endpoint inspection window during finishing, flatness can be improved. It should be noted that, in the third embodiment, these two types of flatness are collectively referred to as "flatness".

[0260] Figure 1 A schematic perspective view of the abrasive pad according to the third embodiment is shown. Figure 1As shown, the abrasive pad 10 of the third embodiment has an abrasive layer 11 and an endpoint detection window 12. If necessary, a buffer layer 13 may also be provided on the side opposite to the abrasive surface 11a.

[0261] Figures 2-3 Show Figure 1 A cross-sectional view of the periphery of the endpoint detection window 12. (See also...) Figures 2-3 As shown, an adhesive layer 14 can also be provided between the grinding layer 11 and the buffer layer 13. Alternatively, an adhesive layer 14 can be provided on the surface of the buffer layer 13 for bonding with the ground layer 11. Figure 4 The adhesive layer 15 is attached to the workbench 22. The abrasive surface 11a of the abrasive pad in the third embodiment, in addition to... Figure 2 Besides the flat scenario shown, it can also be as follows: Figure 3 The diagram shows a concave-convex shape with grooves 16. Grooves 16 can also be formed individually or in combination to form multiple grooves of various shapes such as concentric circles, grids, and radial patterns.

[0262] 3.1.1. Endpoint Detection Window

[0263] The endpoint detection window is a transparent component located at the opening of the polished layer, serving as a light transmission path from the film thickness sensor in optical endpoint detection. In the third embodiment, the endpoint detection window is circular, but it can also be square, rectangular, polygonal, elliptical, or other shapes as needed.

[0264] In the third embodiment, during the manufacturing of the polishing pad, when slicing is performed, the endpoint detection window is prevented from becoming concave or ruptured compared to the polishing layer, and the endpoint detection window is prevented from becoming concave or convex compared to the polishing layer during the finishing process, thereby improving flatness. From this point of view, parameters related to the pulse NMR of the endpoint detection window and the polishing layer are specified.

[0265] 3.1.1.1. Pulsed NMR

[0266] Pulsed NMR is a type of solid-state NMR that detects the response signal to a pulse to determine the sample's properties. 1 The method of H nuclear magnetic resonance relaxation time (an indicator of molecular mobility) is used. As a response to a pulse, the free induction decay (FID) signal is used.

[0267] Pulse NMR is an analytical method for evaluating the overall mobility of a polymer molecular chain system. Mobility is assessed by measuring the relaxation time and signal intensity of the resin composition at that time. Generally, the lower the mobility of the polymer chains, the shorter the relaxation time, and therefore the faster the signal intensity decays; the relative signal intensity at an initial signal intensity of 100% decreases rapidly. Conversely, the higher the mobility of the polymer chains, the longer the relaxation time, and therefore the slower the signal intensity decays; the relative signal intensity at an initial signal intensity of 100% decreases slowly over a longer period.

[0268] For example, when measuring resin, the obtained FID is the sum of the FIDs of multiple components with different relaxation times. By separating them using the least squares method, the relaxation time of each component can be detected. If the free induction decay curve at a specified temperature obtained by pulsed NMR solid-state echo method is approximated with three components, it is possible to classify which component in the sample the signal obtained by this measurement comes from (the component with the lowest mobility (crystalline phase), the intermediate component with intermediate mobility (intermediate phase), and the component with the highest mobility (amorphous phase). In addition, the presence ratio of these components can be determined.

[0269] Specifically, by fitting the free induction decay curve determined by the solid-state echo method of pulsed NMR using the following formula (1), it can be approximated as three components: crystalline phase, intermediate phase and amorphous phase. By approximating these three components, the composition of each component can be obtained.

[0270] M(t)=αexp(-(1 / 2)(t / T α ) 2 )sinbt / bt+βexp(-(1 / Wa)(t / T β ) Wa ) + γexp(-t / T γ (Equation 1)

[0271] α: Composition fraction of the crystalline phase

[0272] T α Relaxation time of the crystalline phase (unit: msec (milliseconds))

[0273] β: Composition fraction of the intermediate phase

[0274] T β Relaxation time of the intermediate phase (unit: msec)

[0275] γ: Composition fraction of the amorphous phase

[0276] T γ Relaxation time of amorphous phase (unit: msec)

[0277] t: Observation time (unit: msec)

[0278] Wa: Shape factor

[0279] b: Shape factor

[0280] Based on the results of such pulsed NMR measurements, the mobility of the polished layer and the endpoint detection window can be evaluated. In the third embodiment, the mobility of the polished layer and the endpoint detection window is evaluated using pulsed NMR at temperatures equivalent to 20°C during trimming and 80°C during slicing, assuming similarities.

[0281] Specifically, at 20°C, the ratio of the amorphous phase presence ratio Lw20 of the endpoint detection window to the amorphous phase presence ratio Lp20 of the polishing layer (Lp20 / Lw20) is 0.5 to 2.0, preferably 0.6 to 1.7, more preferably 0.7 to 1.5, and even more preferably 0.8 to 1.2. By keeping the ratio (Lp20 / Lw20) within the above range, the mobility of the materials constituting the polishing layer and the endpoint detection window becomes similar during finishing. Therefore, the polishing layer and the endpoint detection window can be uniformly processed during finishing, and the flatness after finishing is further improved.

[0282] Furthermore, the ratio of the presence ratio of the crystalline phase Sw80 in the endpoint detection window to the presence ratio of the crystalline phase Sp80 in the polishing layer (Sp80 / Sw80) at 80°C is 0.5 to 2.0, preferably 0.6 to 1.7, more preferably 0.9 to 1.5, and even more preferably 1.0 to 1.3. By keeping the ratio (Sp80 / Sw80) within the above range, the mobility of the materials constituting the polishing layer and the endpoint detection window is similar in the slicing process. Therefore, the polishing layer and the endpoint detection window can be uniformly processed in the slicing process, and the flatness of the sliced ​​surface is further improved.

[0283] The ratio of the presence ratio of the intermediate phase in the endpoint detection window (Mw20) to the presence ratio of the intermediate phase in the polished layer (Mp20) at 20°C (Mp20 / Mw20) is preferably 0.7 to 1.5, more preferably 0.7 to 1.3, and even more preferably 0.7 to 1.1. With the ratio (Mp20 / Mw20) within the above range, the polished layer and the endpoint detection window can be uniformly processed during the finishing process, and there is a tendency to further improve the flatness after finishing.

[0284] The ratio of the presence ratio of the intermediate phase in the endpoint detection window (Mw80) to the presence ratio of the intermediate phase in the polishing layer (Mp80) at 80°C (Mp80 / Mw80) is preferably 0.5 to 1.5, more preferably 0.7 to 1.4, and even more preferably 0.8 to 1.3. By keeping the ratio (Mp80 / Mw80) within the above range, the polishing layer and the endpoint detection window can be uniformly processed during the slicing process, and there is a tendency to further improve the flatness of the sliced ​​surface.

[0285] The difference between the presence ratio Lw20 and the presence ratio Lp20 (|Lp20-Lw20|) is preferably 10 or less, more preferably 0 to 8.0, and even more preferably 0 to 5.0. By making the difference (|Lp20-Lw20|) within the above range, the polishing layer and the endpoint detection window can be uniformly processed in the finishing process, and there is a tendency to further improve the flatness after finishing.

[0286] The difference between the presence ratio Sw80 and the presence ratio Sp80 (|Sp80-Sw80|) is preferably 15 or less, more preferably 0 to 12, and even more preferably 0 to 8.0. By making the difference (|Sp80-Sw80|) within the above range, the grinding layer and the endpoint detection window can be uniformly processed in the slicing process, and the flatness of the sliced ​​surface tends to be further improved.

[0287] The presence of the crystalline phase at 20°C in the endpoint detection window is preferably 30-65% of Sw20, more preferably 35-60%, and even more preferably 40-55%.

[0288] The presence ratio of the intermediate phase in the endpoint detection window at 20°C is preferably 15-45%, more preferably 20-40%, and even more preferably 25-35%.

[0289] The presence ratio of the amorphous phase in the endpoint detection window at 20°C is preferably 10-40%, more preferably 15-35%, and even more preferably 20-30%.

[0290] By setting the presence ratios Sw20, Mw20, and Lw20 of the endpoint detection window at 20°C to the ranges mentioned above, the polished layer and the endpoint detection window can be uniformly processed during the finishing process, resulting in a trend of further improved flatness after finishing. It should be noted that the sum of the presence ratios Sw20, Mw20, and Lw20 is 100%.

[0291] The presence of crystalline phase in the endpoint detection window at 80°C is preferably 15-50% of Sw80, more preferably 20-45%, and even more preferably 25-40%.

[0292] The presence of the intermediate phase in the endpoint detection window at 80°C is preferably 10-35% of Mw80, more preferably 15-30%, and even more preferably 20-25%.

[0293] The presence of the amorphous phase in the endpoint detection window at 80°C is preferably 30-60% of Lw80, more preferably 35-55%, and even more preferably 40-50%.

[0294] By ensuring that the presence ratios Sw80, Mw80, and Lw80 of the endpoint detection window at 80°C are within the aforementioned ranges, the polishing layer and the endpoint detection window can be uniformly processed during slicing, resulting in a trend of further improved flatness after slicing. It should be noted that the sum of the presence ratios Sw80, Mw80, and Lw80 is 100%.

[0295] There are no particular restrictions on the measurement conditions for pulse NMR; the measurements can be performed using the conditions described in the examples.

[0296] 3.1.1.3. Constituent Materials

[0297] The material constituting the endpoint detection window can be any transparent component capable of functioning as a window, without particular limitations. Examples include polyurethane resin WI, polyvinyl chloride resin, polyvinylidene fluoride resin, polyethersulfone resin, polystyrene resin, polyethylene resin, and polytetrafluoroethylene resin. Among these, polyurethane resin WI is preferred. By using such a resin, it is easier to adjust the aforementioned pulse NMR characteristics and transparency, and flatness can be further improved.

[0298] Polyurethane resin WI can be synthesized from polyisocyanates and polyols, containing structural units from polyisocyanates and structural units from polyols.

[0299] 3.1.1.3.1. Structural units derived from polyisocyanates

[0300] The structural units derived from polyisocyanates are not particularly limited; examples include structural units derived from alicyclic isocyanates, aliphatic isocyanates, and aromatic isocyanates. The polyurethane resin WI preferably contains structural units derived from alicyclic and / or aliphatic isocyanates, and more preferably from aliphatic isocyanates. This makes it easier to adjust the values ​​related to pulsed NMR to the aforementioned ranges, further improving transparency and flatness during trimming and sectioning.

[0301] There are no particular limitations on whether the isocyanate is alicyclic, aliphatic, or aromatic; for example, the compounds exemplified in the first embodiment can be cited.

[0302] 3.1.1.3.2. Structural units derived from polyols

[0303] As a structural unit derived from polyols, there are no particular limitations; for example, low molecular weight polyols with a molecular weight of less than 300 and high molecular weight polyols with a molecular weight of more than 300 can be cited.

[0304] There are no particular limitations on the low molecular weight polyols; for example, the compounds exemplified in the first embodiment can be cited.

[0305] Among them, low-molecular-weight polyols with three or more hydroxyl groups are preferred, and glycerol is more preferred. By using such low-molecular-weight polyols, the pulse NMR characteristics can be easily adjusted to the above-mentioned range, the wear amount can be adjusted, the flatness can be further improved, and in addition to further improving the transparency, there is also a trend of further improving the window's resistance to yellowing.

[0306] The content of structural units from low-molecular-weight polyols having three or more hydroxyl groups is preferably 8.0 to 30 parts by mass relative to 100 parts by mass of structural units from polyisocyanates, more preferably 10 to 25 parts by mass, and even more preferably 12.5 to 20 parts by mass. By keeping the content of structural units from low-molecular-weight polyols having three or more hydroxyl groups within the above range, it is easier to adjust the pulse NMR characteristics to the above range, further improving flatness, transparency, and the window's resistance to yellowing.

[0307] Furthermore, there are no particular limitations on the high molecular weight polyol; for example, the compound exemplified in the first embodiment can be cited.

[0308] Furthermore, the number average molecular weight of the high molecular weight polyol is preferably 300 to 3000, more preferably 500 to 2500. By using such a high molecular weight polyol, it is easier to adjust the pulse NMR characteristics to the above range.

[0309] Among them, polyether polyols are preferred, and poly(oxytetramethylene) glycols are more preferred. By using such high-molecular-weight polyols, the pulsed NMR characteristics can be easily adjusted to the aforementioned range. In addition, besides further improving flatness and transparency, there is also a tendency to further improve the window's resistance to yellowing.

[0310] The content of structural units from polyether polyols is preferably 60 to 130 parts by mass, more preferably 65 to 120 parts by mass, and more preferably 70 to 110 parts by mass, relative to 100 parts by mass of structural units from polyisocyanates. By keeping the content of structural units from polyether polyols within the above range, the pulsed NMR characteristics can be easily adjusted to the above range, and the flatness can be further improved. In addition to further improving transparency, there is also a tendency to further improve the window's resistance to yellowing.

[0311] Furthermore, as the polyol, it is preferable to use a combination of low-molecular-weight polyols and high-molecular-weight polyols, and more preferably, a combination of low-molecular-weight polyols having three or more hydroxyl groups and polyether polyols. This makes it easier to adjust the pulsed NMR characteristics to the aforementioned range. In addition to further improving flatness and transparency, it also tends to further improve the window's resistance to yellowing.

[0312] Based on the above viewpoint, the content of polyether polyol is preferably 2.0 to 15.0 parts, more preferably 3.0 to 12.5 parts, and even more preferably 4.0 to 9.0 parts, relative to 1 part of low molecular weight polyol having 3 or more hydroxyl groups.

[0313] 3.1.2. Abrasive Layer

[0314] The polishing layer of the third embodiment has an opening for embedding an end-point detection window. The location of the opening is not particularly limited, but it is preferably located in a radial direction corresponding to the film thickness detection sensor 23 provided on the worktable 22. Furthermore, the number of openings is not particularly limited, but it is preferable to have multiple openings at the same radial direction so that the window passes over the film thickness detection sensor 23 multiple times as the polishing pad 10 adhered to the worktable 22 rotates one revolution.

[0315] There are no particular limitations on the type of abrasive layer, for example, a resin-foamed molded body, a non-foamed molded body, or a resin-impregnated substrate containing resin in a fiber substrate.

[0316] Here, regarding the foamed molded body, the non-foamed molded body, the resin impregnated substrate, and the fiber substrate, the methods described in the first embodiment can be cited, and therefore the description is omitted.

[0317] 3.1.2.1. Pulsed NMR

[0318] The crystalline phase content of the polishing layer is preferably 40-65%, more preferably 45-60%, and more preferably 50-55% of Sp20.

[0319] The presence of the intermediate phase in the polishing layer is preferably 10-40%, more preferably 15-35%, and more preferably 20-30% of Mp20.

[0320] The presence of the amorphous phase in the polishing layer is preferably 10-35% of Lp20, more preferably 15-30%, and more preferably 20-25%.

[0321] By ensuring that the presence ratios Sp20, Mp20, and Lp20 of the endpoint detection window at 20°C fall within the aforementioned ranges, the polished layer and the endpoint detection window can be uniformly processed during the finishing process, resulting in a further improvement in the flatness after finishing. It should be noted that the sum of the presence ratios Sp20, Mp20, and Lp20 is 100%.

[0322] The presence of crystalline phase in the polishing layer is preferably 25-50%, more preferably 30-45%, and even more preferably 35-40% of Sp80.

[0323] The presence of the intermediate phase in the polishing layer is preferably 10-40%, more preferably 15-35%, and more preferably 20-30% of Mp80.

[0324] The presence of the amorphous phase in the polishing layer is preferably 25-50%, more preferably 30-45%, and even more preferably 35-40% of Lp80.

[0325] By ensuring that the presence ratios Sp80, Mp80, and Lp80 of the endpoint detection window at 80°C are within the aforementioned ranges, the polishing layer and the endpoint detection window can be uniformly processed during slicing, further improving the flatness of the slices. It should be noted that the sum of the presence ratios Sp80, Mp80, and Lp80 is 100%.

[0326] There are no particular restrictions on the measurement conditions for pulse NMR; the measurements can be performed using the conditions described in the examples.

[0327] 3.1.2.2. Polyurethane Sheets

[0328] The following example, using a polyurethane sheet, is an example of a polishing layer. The method described in the first embodiment can be used as an example of a polyurethane sheet, therefore, the description is omitted.

[0329] 3.1.3. Other

[0330] The polishing pad of the third embodiment may have a buffer layer on the side of the polishing layer opposite to the polishing surface, or it may have an adhesive layer between the polishing layer and the buffer layer, on the non-polishing side of the buffer layer (the side that fits against the polishing machine). In this case, the buffer layer and the adhesive layer have openings at the same location as the end-point detection window of the polishing layer.

[0331] 4. Fourth Implementation Method

[0332] 4.1. Grinding pad

[0333] The abrasive pad of the fourth embodiment has an abrasive layer and an endpoint detection window provided in the opening of the abrasive layer. In the dynamic viscoelasticity test conducted under the conditions of tensile mode, frequency 1.6 Hz, 30 to 55°C and immersion state, the ratio of the storage modulus E'w40 of the endpoint detection window at 40°C to the storage modulus E'p40 of the abrasive layer at 40°C (E'p40 / E'w40) is 0.70 to 3.00.

[0334] Therefore, during grinding, the dynamic viscoelastic properties of the grinding layer and the endpoint detection window become closer, thus further suppressing the generation of defects (surface defects) on the surface of the workpiece even when the endpoint detection window, which is a dissimilar component, is embedded in the grinding layer. As a result, a workpiece with excellent surface quality can be obtained.

[0335] Figure 1 A schematic perspective view of the abrasive pad according to the fourth embodiment is shown. Figure 1 As shown, the abrasive pad 10 of the fourth embodiment has an abrasive layer 11 and an endpoint detection window 12. If necessary, a buffer layer 13 may also be provided on the side opposite to the abrasive surface 11a.

[0336] Figures 2-3 Show Figure 1 A cross-sectional view of the periphery of the endpoint detection window 12 in the image. (See image for details.) Figures 2-3 As shown, an adhesive layer 14 can also be provided between the grinding layer 11 and the buffer layer 13. Alternatively, an adhesive layer 14 can be provided on the surface of the buffer layer 13 for bonding with the ground layer 11. Figure 4 The adhesive layer 15 is attached to the workbench 22. The abrasive surface 11a of the abrasive pad in the fourth embodiment, in addition to... Figure 2 Besides the flat scenario shown, it can also be as follows: Figure 3 The diagram shows a concave-convex shape with grooves 16. Grooves 16 can also be formed individually or in combination to form multiple grooves of various shapes such as concentric circles, grids, and radial patterns.

[0337] 4.1.1. Endpoint Detection Window

[0338] The endpoint detection window is a transparent component located at the opening of the polished layer, serving as a light transmission path from the film thickness sensor in optical endpoint detection. In the fourth embodiment, the endpoint detection window is circular, but it can also be square, rectangular, polygonal, elliptical, or other shapes as needed.

[0339] In the fourth embodiment, from the viewpoint of adjusting the wear degree of the endpoint detection window and the grinding layer during grinding, so that either the endpoint detection window or the grinding layer is over-ground and a defect (surface defect) is generated on the non-grinding material, the ratio of the storage modulus E' of the endpoint detection window to the grinding layer is specified.

[0340] 4.1.1.1. Dynamic viscoelasticity

[0341] In the fourth embodiment, the storage modulus E' of the endpoint detection window and the abrasive layer can be determined by dynamic viscoelasticity measurement performed under tensile conditions, a frequency of 1.6 Hz, a temperature of 30–55°C, and an immersion state. Furthermore, unless otherwise specified in this embodiment, the dynamic viscoelasticity measurement is assumed to be performed under immersion conditions.

[0342] In the grinding process where the slurry contacts the grinding pad, the grinding surface is immersed in water. Therefore, in the fourth embodiment, at 40°C, which is equivalent to the temperature during grinding, the ratio of the endpoint detection window and the dynamic viscoelasticity of the grinding layer in the immersed state is specified. More specifically, in the dynamic viscoelasticity measurement performed under tensile mode, frequency 1.6 Hz, temperature 30–55°C, and immersed state conditions, the ratio (E'p40 / E'w40) of the storage modulus E'w40 of the endpoint detection window at 40°C to the storage modulus E'p40 of the grinding layer at 40°C is specified.

[0343] The ratio (E'p40 / E'w40) is 0.70 to 3.00, preferably 0.80 to 2.50, and more preferably 0.90 to 2.00. By keeping the ratio (E'p40 / E'w40) within the above range, the characteristics of the endpoint detection window and the grinding layer are similar during grinding, thus further improving the surface quality of the workpiece. This optimizes the contact state between the workpiece and the grinding material during grinding, and also suppresses the continuous pressing of grinding debris and the formation of scratches.

[0344] In the above-mentioned dynamic viscoelasticity measurement under immersion conditions, the ratio (E'p50 / E'w50) of the storage modulus E'w50 of the endpoint detection window at 50°C to the storage modulus E'p50 of the abrasive layer at 50°C is preferably 0.70 to 5.00, more preferably 0.80 to 4.00, and even more preferably 0.90 to 3.00. By keeping the ratio (E'p50 / E'w50) within the above range, the characteristics of the endpoint detection window and the abrasive layer during abrasion are similar, thus tending to further improve the surface quality of the abraded object.

[0345] In the above dynamic viscoelasticity measurement under immersion conditions, the difference between the loss factor tanδw30 of the endpoint detection window at 30°C and the loss factor tanδp30 of the abrasive film at 30°C (|tanδw30-tanδp30|) is preferably 0 to 0.30, more preferably 0.05 to 0.30, and even more preferably 0.05 to 0.20.

[0346] In the above-mentioned dynamic viscoelasticity measurement under immersion conditions, the difference between the loss factor tanδw40 of the endpoint detection window at 40°C and the loss factor tanδp40 of the abrasive film at 40°C (|tanδw40-tanδp40|) is preferably 0 to 0.40, more preferably 0.05 to 0.40, and even more preferably 0.05 to 0.30.

[0347] In the above-mentioned dynamic viscoelasticity measurement under immersion conditions, the difference between the loss factor tanδw50 of the endpoint detection window at 50°C and the loss factor tanδp50 of the endpoint detection window at 50°C (|tanδw50-tanδp50|) is preferably 0 to 0.50, more preferably 0.05 to 0.50, and even more preferably 0.05 to 0.40.

[0348] By making the differences (|tanδw30-tanδp30|), (|tanδw40-tanδp40|), and (|tanδw50-tanδp50|) within the above ranges, the characteristics of the endpoint detection window during grinding are similar to those of the endpoint detection window during grinding, thus there is a tendency to further improve the surface quality of the obtained workpiece.

[0349] The storage modulus E'w40 of the endpoint detection window at 40°C under immersion conditions is preferably 6.0~50×10. 7 Pa, more preferably 8.0 to 40 × 10 Pa. 7 Pa, more preferably 10 to 30 × 10 7 Pa.

[0350] Storage modulus E' at 50°C of the endpoint detection window under immersion conditions w50 Preferably 2.0~40×10 7 Pa, more preferably 3.0 to 30 × 10 Pa. 7 Pa, more preferably 4.0 to 20 × 10 Pa. 7 Pa.

[0351] The tanδw40 of the endpoint detection window at 40°C under immersion conditions is preferably 0.1 to 0.7, more preferably 0.1 to 0.6, and even more preferably 0.1 to 0.5.

[0352] The tanδw50 of the endpoint detection window at 50°C under immersion conditions is preferably 0.1 to 0.6, more preferably 0.1 to 0.5, and even more preferably 0.1 to 0.4.

[0353] By keeping E'w40, E'w50, tanδw40, and tanδw50 within the aforementioned ranges, the characteristics of the endpoint detection window and the grinding layer during grinding are similar, thus there is a tendency to further improve the surface quality of the resulting workpiece.

[0354] There are no particular restrictions on the testing conditions for dynamic viscoelasticity; the testing can be performed using the conditions described in the examples.

[0355] 4.1.1.3. Constituent Materials

[0356] The material constituting the endpoint detection window can be any transparent component capable of functioning as a window; there are no particular limitations. Examples include polyurethane resin WI, polyvinyl chloride resin, polyvinylidene fluoride resin, polyethersulfone resin, polystyrene resin, polyethylene resin, and polytetrafluoroethylene resin. Among these, polyurethane resin WI is preferred. By using such a resin, it is easier to adjust the aforementioned dynamic viscoelastic properties and transparency, thereby further improving surface quality.

[0357] Polyurethane resin WI can be synthesized from polyisocyanates and polyols, containing structural units from polyisocyanates and structural units from polyols.

[0358] 4.1.1.3.1. Structural units derived from polyisocyanates

[0359] The structural units derived from polyisocyanates are not particularly limited; examples include structural units derived from alicyclic isocyanates, aliphatic isocyanates, and aromatic isocyanates. The polyurethane resin WI preferably contains structural units derived from alicyclic and / or aliphatic isocyanates, and more preferably from aliphatic isocyanates. This makes it easier to adjust the dynamic viscoelastic properties to the aforementioned range, resulting in further improvements in transparency and surface quality.

[0360] There are no particular limitations on whether the isocyanate is alicyclic, aliphatic, or aromatic; for example, the compounds exemplified in the first embodiment can be cited.

[0361] 4.1.1.3.2. Structural units derived from polyols

[0362] As a structural unit derived from polyols, there are no particular limitations; for example, low molecular weight polyols with a molecular weight of less than 300 and high molecular weight polyols with a molecular weight of more than 300 can be cited.

[0363] There are no particular limitations on the low molecular weight polyols; for example, the compounds exemplified in the first embodiment can be cited.

[0364] Among them, low-molecular-weight polyols with three or more hydroxyl groups are preferred, and glycerol is more preferred. By using such low-molecular-weight polyols, the dynamic viscoelastic properties can be easily adjusted to the above-mentioned range, the amount of wear can be adjusted, and in addition to further improving transparency, there is also a trend of further improving surface quality.

[0365] The content of structural units from low-molecular-weight polyols having three or more hydroxyl groups is preferably 7.5 to 30 parts by mass relative to 100 parts by mass of structural units from polyisocyanates, more preferably 10 to 25 parts by mass, and even more preferably 12.5 to 20 parts by mass. By keeping the content of structural units from low-molecular-weight polyols having three or more hydroxyl groups within the above range, the dynamic viscoelastic properties can be easily adjusted to the above range, and in addition to further improving transparency, there is a tendency to further improve surface quality.

[0366] Furthermore, there are no particular limitations on the high molecular weight polyol; for example, the compound exemplified in the first embodiment can be cited.

[0367] Furthermore, the number average molecular weight of the polymeric polyol is preferably 300 to 3000, more preferably 500 to 2500. By using such a polymeric polyol, it is easier to adjust the dynamic viscoelastic properties to the above range.

[0368] Among them, polyether polyols are preferred, and poly(oxytetramethylene) glycol is more preferred. By using such high-molecular-weight polyols, the dynamic viscoelastic properties can be easily adjusted to the aforementioned range. In addition, besides further improving transparency, there is also a trend towards further improving the window's resistance to yellowing.

[0369] The content of structural units from polyether polyols is preferably 60 to 130 parts by weight, more preferably 65 to 120 parts by weight, and more preferably 70 to 110 parts by weight, relative to 100 parts by weight of structural units from polyisocyanates. By keeping the content of structural units from polyether polyols within the above range, the dynamic viscoelastic properties can be easily adjusted to the above range, and in addition to further improving transparency, there is a tendency to further improve the window's resistance to yellowing.

[0370] Furthermore, as the polyol, it is preferable to use a combination of low-molecular-weight polyols and high-molecular-weight polyols, and more preferably, a combination of low-molecular-weight polyols having three or more hydroxyl groups and polyether polyols. This makes it easier to adjust the dynamic viscoelastic properties to the aforementioned range, resulting in further improvements not only in transparency but also in the window's resistance to yellowing.

[0371] Based on the above viewpoint, the content of polyether polyol is preferably 2.0 to 15.0 parts, more preferably 3.0 to 12.5 parts, and even more preferably 4.0 to 9.0 parts, relative to 1 part of low molecular weight polyol having 3 or more hydroxyl groups.

[0372] 4.1.2. Abrasive Layer

[0373] The polishing layer of the fourth embodiment has an opening for embedding an end-point detection window. The location of the opening is not particularly limited, but it is preferably located in a radial direction corresponding to the film thickness detection sensor 23 provided on the worktable 22. Furthermore, the number of openings is not particularly limited, but it is preferable to have multiple openings in the same radial direction so that the window passes over the film thickness detection sensor 23 multiple times as the polishing pad 10 adhered to the worktable 22 rotates one revolution.

[0374] There are no particular limitations on the type of abrasive layer, for example, a resin-foamed molded body, a non-foamed molded body, or a resin-impregnated substrate containing resin in a fiber substrate.

[0375] Here, regarding the foamed molded body, the non-foamed molded body, the resin impregnated substrate, and the fiber substrate, the methods described in the first embodiment can be cited, and therefore the description is omitted.

[0376] 4.1.2.1. Dynamic viscoelasticity

[0377] The storage modulus E'p40 of the polishing layer at 40°C under immersion conditions is preferably 10 to 40 × 10⁻⁶. 7 Pa, more preferably 15 to 35 × 10 Pa 7 Pa, more preferably 20–30 × 10⁻⁶ 7 Pa.

[0378] Storage modulus E' of the polishing layer at 50°C under immersion in water p50 Preferably 50~35×10 7 Pa, more preferably 10 to 30 × 10 Pa 7 Pa, more preferably 15–25 × 10⁻⁶ 7 Pa.

[0379] The tanδp40 of the polishing layer at 40°C under immersion conditions is preferably 0.01 to 0.25, more preferably 0.03 to 0.20, and even more preferably 0.05 to 0.15.

[0380] The tanδp50 of the polishing layer at 50°C under immersion conditions is preferably 0.01 to 0.25, more preferably 0.03 to 0.20, and even more preferably 0.05 to 0.15.

[0381] By making E' p40 、E' p50 , tanδ p40 and tanδ p50 Within the aforementioned ranges, the characteristics of the endpoint detection window and the grinding layer are similar, thus there is a trend towards further improvement in the surface quality of the resulting workpiece.

[0382] 4.1.2.2. Polyurethane Sheets

[0383] The following example, as a polishing layer, illustrates a polyurethane sheet. Regarding the polyurethane sheet, the method described in the first embodiment can be cited, therefore, the description is omitted.

[0384] 4.1.3. Other

[0385] The polishing pad of the fourth embodiment may have a buffer layer on the side of the polishing layer opposite to the polishing surface, or it may have an adhesive layer between the polishing layer and the buffer layer, on the non-polishing side of the buffer layer (the side that fits against the polishing machine). In this case, the buffer layer and the adhesive layer have openings at the same location as the end-point detection window of the polishing layer.

[0386] 5. Manufacturing method of grinding pad

[0387] The manufacturing method of the abrasive pad according to the first to fourth embodiments is not particularly limited. For example, it includes the following steps: filling a resin composition constituting the abrasive layer into a mold in which a window component that serves as an endpoint detection window is fixed and curing it to obtain a resin block without a window component; and slicing the obtained resin block to obtain a polyurethane sheet with an endpoint detection window at the opening. If necessary, the abrasive surface of the obtained polyurethane sheet may also be trimmed in the manufacturing method.

[0388] It should be noted that the preferred temperature for slicing is 70℃~100℃. Furthermore, the preferred temperature for trimming is 20℃~30℃. This results in a further improvement in flatness.

[0389] 6. Manufacturing method of ground workpiece

[0390] The manufacturing method of the abrasive workpiece according to the first to fourth embodiments includes a grinding step in which the workpiece is ground using the above-mentioned grinding pad in the presence of a grinding slurry to obtain the abrasive workpiece; and an endpoint detection step in which the endpoint is detected by an optical endpoint detection method during the grinding process.

[0391] 6.1 Grinding process

[0392] The grinding process can be a single wiping (rough wiping) or a double wiping (fine wiping), or a single polishing (rough polishing) or a double polishing (fine polishing), or a combination of these grinding processes. It should be noted that, here, "lapping" refers to grinding with coarse abrasive grains at a relatively high rate, while "polishing" refers to grinding with fine abrasive grains at a relatively low rate to improve surface quality.

[0393] The abrasive pads of the first to fourth embodiments are preferably used for chemical mechanical polishing (CMP). Hereinafter, the manufacturing method of the abrasive material of the first to fourth embodiments will be described using chemical mechanical polishing as an example, but the manufacturing method of the abrasive material of the first to fourth embodiments is not limited to the following.

[0394] The material to be polished is not particularly limited, and examples include materials such as semiconductor devices and electronic components, especially thin substrates such as Si substrates (silicon wafers), SiC (silicon carbide) substrates, GaAs (gallium arsenide) substrates, glass, hard disks, and LCD (liquid crystal display) substrates. In particular, semiconductor devices with metal wiring such as W (tungsten) and Cu (copper) can be cited.

[0395] As a grinding method, conventionally known methods can be used without particular limitation. For example, firstly, the workpiece to be ground, held by a holding platform positioned opposite the grinding pad, is pressed towards the grinding surface, and while slurry is supplied from the outside, the grinding pad and / or the holding platform are rotated. The grinding pad and the holding platform can rotate in the same direction at different rotational speeds, or they can rotate in different directions. Alternatively, the workpiece to be ground can be ground while moving (rotating) inside the frame during the grinding process.

[0396] The slurry contains chemical components such as water and oxidants (represented by hydrogen peroxide), additives, and abrasive particles (grinding particles; for example, SiC, SiO2, Al2O3, CeO2), depending on the material being ground and the grinding conditions.

[0397] 6.2. Endpoint testing procedure

[0398] The manufacturing method for the polished workpiece according to the first to fourth embodiments includes an endpoint detection step in the above-described polishing process, which performs endpoint detection using an optical endpoint detection method. Specifically, conventionally known methods can be used as the endpoint detection method utilizing the optical endpoint detection method.

[0399] Figure 4 This diagram illustrates an optical endpoint detection method. The diagram shows a chemical mechanical polishing (CMP) process in which slurry 24 flows onto a polishing pad 10 attached to a worktable 22 while a wafer W held by a top ring 21 is pressed, thereby planarizing the uneven film on the surface of the wafer W. In the polishing apparatus 20, a film thickness sensor 23 is mounted on the worktable 22 to accurately end the process while simultaneously planarizing the film and detecting the specified film thickness. The film thickness sensor 23, for example, illuminates the polishing surface of the wafer W with light, and by measuring and analyzing the spectroscopic intensity characteristics of the reflected light, the polishing endpoint can be detected.

[0400] More specifically, the film thickness sensor 23 incident light onto the surface of the wafer W through the endpoint detection window 12, and detects the change in film thickness by detecting the intensity of reflection caused by the phase difference between the light reflected by the film (wafer surface) on the wafer W and the light reflected by the interface between the film on the wafer W and the substrate of the wafer.

[0401] Example

[0402] The present invention will now be described in more detail using examples and comparative examples. The present invention is not limited to the following examples. It should be noted that "parts" refers to parts by weight.

[0403] [Example A]

[0404] [Manufacturing Example A1: Endpoint Inspection Window A1]

[0405] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 78.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 650 and 14.8 parts of glycerol were reacted to obtain a transparent component that serves as the endpoint detection window A1.

[0406] [Manufacturing Example A2: Endpoint Inspection Window A2]

[0407] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 78.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 650, 7.5 parts of glycerol, and 7.5 parts of ethylene glycol were reacted to obtain a transparent component that serves as the endpoint detection window A2.

[0408] [Manufacturing Example 3: Endpoint Inspection Window A3]

[0409] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 78.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 650, 4.5 parts of glycerol, and 10.5 parts of ethylene glycol were reacted to obtain a transparent component that serves as the endpoint detection window A3.

[0410] [Manufacturing Example 4: Endpoint Inspection Window A4]

[0411] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 103.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and 15.9 parts of glycerol were reacted to obtain a transparent component that serves as the endpoint detection window A4.

[0412] [Example A1]

[0413] To 100 parts of a urethane prepolymer with an NCO equivalent of 455 obtained by reacting 2,4-toluene 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), 2.7 parts of unexpanded hollow microparticles (average particle size: 8.5 μm) formed from acrylonitrile-vinylidene chloride copolymer were added to obtain a urethane prepolymer mixture. The obtained urethane prepolymer mixture was placed in a first liquid tank and kept at 60°C. Separately from the first liquid tank, 25.8 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylene bis(o-chloroaniline)) (MOCA) were added to a second liquid tank as a curing agent, heated to 120°C to melt and mix, and further subjected to degassing under reduced pressure to obtain a curing agent melt.

[0414] Next, the liquids from the first and second liquid tanks are injected into the respective inlets of a mixer equipped with two injection ports, and stirred to obtain a mixture.

[0415] The resulting mixture was then poured into a mold pre-set with the endpoint detection window A1 as described above, and cured once at 80°C for 30 minutes. The resulting block was removed from the mold and cured a second time in an oven at 120°C for 4 hours to obtain a polyurethane resin block. The obtained polyurethane resin block was then allowed to cool naturally to 25°C.

[0416] Then, after heating in an oven at 120°C for 5 hours, the material is sliced. The sliced ​​surfaces are then ground (polished) as needed to obtain a polyurethane foam sheet. Double-sided tape is then applied to the back of the polyurethane sheet to attach a buffer layer, and then double-sided tape is applied to the surface of the buffer layer to obtain a grinding pad.

[0417] It should be noted that when evaluating the cross-section around the endpoint detection window after the finishing process, the grinding pad obtained as described above is finished under the following conditions.

[0418] (Revision conditions)

[0419] Grinding machine used: Speedfam, product name "FAM-12BS"

[0420] Platform speed (grinding pad speed): 50 rpm

[0421] Flow rate: 100 ml / min (drip 20°C pure water from the center of the rotating grinding pad).

[0422] Dressing machine: A diamond dressing machine manufactured by 3M, model "A188".

[0423] Dressing machine speed: 100 rpm

[0424] Dressing pressure: 0.115 kg / cm 2

[0425] The dressing machine rotates in the same direction as the grinding pad.

[0426] Test duration: 60 minutes

[0427] [Comparative Example A1]

[0428] Except for using the endpoint detection window A2 of manufacturing example A2, the grinding pad is obtained in the same manner as in example A1.

[0429] [Comparative Example A2]

[0430] Except for using the endpoint detection window A3 of manufacturing example A3, the grinding pad is obtained in the same manner as in example A1.

[0431] [Example A2]

[0432] Except for using the endpoint detection window A4 of manufacturing example A4, the abrasive pad is obtained in the same manner as in example A1.

[0433] [Dynamic Viscoelasticity Measurement]

[0434] Based on the following conditions, polyurethane sheets that had been kept dry for 40 hours in a constant temperature and humidity bath at 23℃ (±2℃) and 50% (±5%) relative humidity were used as samples for dynamic viscoelasticity determination under normal atmospheric conditions (dry state). It should be noted that the sample dimensions for the endpoint detection window were 5cm (length) × 0.5cm (width) × 0.125cm (thickness), and the sample dimensions for the abrasive layer were 5cm (length) × 0.5cm (width) × 0.13cm (thickness).

[0435] (Measurement conditions)

[0436] Measurement apparatus: RSA III (manufactured by TA Instruments)

[0437] Test length: 1cm

[0438] Test mode: Tension

[0439] Frequency: 1.0Hz

[0440] Temperature range: 10~100℃

[0441] Heating rate: 3.0℃ / min

[0442] Strain range: 0.10%

[0443] Initial load: 300g

[0444] Measurement interval: 1.5 points / ℃

[0445] [D Hardness]

[0446] D hardness was measured according to JIS K6253. During the measurement, a D hardness tester manufactured by TECLOCK was used. For the sample, four overlaps were made of the endpoint detection windows (approximately 0.125 cm (1.25 mm) thick) described in Comparative Example A and Example A, with a total thickness of at least 0.45 cm (4.5 mm). It should be noted that the samples used were those that had been placed in a constant temperature and humidity bath at 20°C or 80°C for 30 minutes.

[0447] [Cross-section evaluation]

[0448] For each pad obtained as described above, the periphery of the endpoint detection window in the state after slicing and before trimming ( Figure 2 The part enclosed by the dashed line S) and (evaluation A1), the perimeter of the endpoint detection window of the adjusted state ( Figure 2 The cross section (evaluation A2) of the portion enclosed by the dashed line S was observed using a laser microscope (VK-X1000, KEYENCE) at an area of ​​approximately 14 mm × 1 mm, magnified 200 times. The observation was performed in connected mode, and the contour measurement of height information was performed based on the obtained laser image.

[0449] The results are shown in Figure 5A ~D、 Figure 6A ~D. It should be noted that, in Figure 5A ~D、 Figure 6A In ~D, the cross-sectional measurement results of the endpoint detection window at point 2 are shown. These results are obtained by measuring the cross-section of each endpoint detection window in the slicing direction and in the direction perpendicular to the slicing direction.

[0450] In evaluation A1, if the distance between the endpoint detection window and the polished surface is within ±50μm, the evaluation is ○; otherwise, the evaluation is ×. In evaluation A2, a flat cross-sectional image (equal height from the end to the center) is ○, and a convex image (higher height from the end to the center) is ×.

[0451] [Table 1]

[0452]

[0453] [Example B]

[0454] [Manufacturing Example B1: Endpoint Inspection Window B1]

[0455] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 120.9 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and 14.8 parts of glycerol were reacted to obtain a transparent component that serves as the endpoint detection window B1.

[0456] [Manufacturing Example B2: Endpoint Inspection Window B2]

[0457] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 103.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and 15.9 parts of glycerol were reacted to obtain a transparent component that serves as the endpoint detection window B2.

[0458] [Manufacturing Example B3: Endpoint Inspection Window B3]

[0459] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 96.7 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and 16.3 parts of glycerol were reacted to obtain a transparent component that serves as the endpoint detection window B3.

[0460] [Manufacturing Example B4: Endpoint Inspection Window B4]

[0461] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 90.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and 16.7 parts of glycerol were reacted to obtain a transparent component that serves as the endpoint detection window B4.

[0462] [Manufacturing Example B5: Endpoint Inspection Window B5]

[0463] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 78.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 650 and 14.8 parts of glycerol were reacted to obtain a transparent component that serves as the endpoint detection window B5.

[0464] [Manufacturing Example B6: Endpoint Inspection Window B6]

[0465] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 78.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 650, 10.5 parts of ethylene glycol, and 4.5 parts of glycerol were reacted to obtain a transparent component that serves as the endpoint detection window B6.

[0466] [Example B1]

[0467] To 100 parts of a urethane prepolymer with an NCO equivalent of 455 obtained by reacting 2,4-toluene 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 microparticles (average particle size: 8.5 μm) formed from acrylonitrile-vinylidene chloride copolymer were added to obtain a urethane prepolymer mixture. The obtained urethane prepolymer mixture was placed in a first liquid tank and kept at 60°C. Separately from the first liquid tank, 25.8 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylene bis(o-chloroaniline)) (MOCA) were added to a second liquid tank as a curing agent, heated to 120°C to melt and mix, and further degassed under reduced pressure to obtain a curing agent melt.

[0468] Next, the liquids from the first and second liquid tanks are injected into the respective inlets of a mixer equipped with two injection ports, and stirred to obtain a mixture.

[0469] The resulting mixture was then poured into a mold pre-set with the endpoint detection window B1 as described above, and cured once at 80°C for 30 minutes. The resulting block was removed from the mold and cured a second time in an oven at 120°C for 4 hours to obtain a polyurethane resin block. The obtained polyurethane resin block was then allowed to cool naturally to 25°C.

[0470] Then, after heating in an oven at 120°C for 5 hours, the material is sliced, and the sliced ​​surface is ground (polished) to obtain a polyurethane foam sheet. Double-sided tape is then applied to the back of the polyurethane sheet to attach a buffer layer, and then double-sided tape is applied to the surface of the buffer layer to obtain a grinding pad.

[0471] [Example B2]

[0472] To 100 parts of a urethane prepolymer with an NCO equivalent of 420 obtained by reacting 2,4-toluene 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 microparticles (average particle size: 8.5 μm) formed from acrylonitrile-vinylidene chloride copolymer were added to obtain a polyurethane prepolymer mixture. The obtained urethane prepolymer mixture was loaded into a first liquid tank and kept at 60°C. In addition, separately from the first liquid tank, 28.0 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylene bis(o-chloroaniline)) (MOCA) as a curing agent were added to the second liquid tank, heated to 120°C to melt and mix, and further degassed under reduced pressure to obtain a curing agent melt. Using the curing agent melt and endpoint detection window B2, the grinding pad was obtained in the same manner as in Example B1.

[0473] [Example B3]

[0474] To 100 parts of a urethane prepolymer with an NCO equivalent of 460 obtained by reacting 2,4-toluene diisocyanate (2,4-TDI), poly(tetramethylene glycol) (PTMG) with an average molecular weight of 650, and diethylene glycol (DEG), 2.8 parts of expanded hollow microparticles (average particle size: 20 μm) formed from an acrylonitrile-vinylidene chloride copolymer were added to obtain a urethane prepolymer mixture. The obtained urethane prepolymer mixture was placed in a first liquid tank and kept at 60°C. In addition, separately from the first liquid tank, 25.5 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylene bis(o-chloroaniline)) (MOCA) and 8.5 parts of polypropylene glycol, which serve as curing agents, are added to the second liquid tank. The mixture is heated to 120°C to melt and mix, and then degassed under reduced pressure to obtain a curing agent melt. Using the curing agent melt and the endpoint detection window B3, the grinding pad is obtained in the same manner as in Example B1.

[0475] [Example B4]

[0476] Except for using the endpoint detection window B2, the abrasive pad is obtained in the same manner as in Example B1.

[0477] [Example B5]

[0478] Except for the use of endpoint detection window B3, the abrasive pad is obtained in the same manner as in Example B1.

[0479] [Example B6]

[0480] Except for the use of endpoint detection window B4, the abrasive pad is obtained in the same manner as in Example B1.

[0481] [Example B7]

[0482] Except for using the endpoint detection window B4, the abrasive pad is obtained in the same manner as in Example B2.

[0483] [Comparative Example B1]

[0484] The abrasive pad was obtained in the same manner as in Example B1, except that the endpoint detection window B5 was used.

[0485] [Comparative Example B2]

[0486] The abrasive pad was obtained in the same manner as in Example B1, except that the endpoint detection window B6 was used.

[0487] [Dynamic Viscoelasticity Measurement]

[0488] Based on the following conditions, the grinding layer and endpoint detection window, which had been kept dry for 40 hours in a constant temperature and humidity bath at 23℃ (±2℃) and 50% (±5%), were used as samples for dynamic viscoelasticity determination under normal atmospheric conditions (dry state). It should be noted that the sample dimensions of the endpoint detection window were 5cm (length) × 0.5cm (width) × 0.125cm (thickness), and the sample dimensions of the grinding layer were 5cm (length) × 0.5cm (width) × 0.13cm (thickness).

[0489] (Measurement conditions)

[0490] Measuring apparatus: RSA III (manufactured by TA Instruments)

[0491] Test length: 1cm

[0492] Test mode: Tension

[0493] Frequency: 1.0Hz

[0494] Temperature range: 10~100℃

[0495] Heating rate: 3.0℃ / min

[0496] Strain range: 0.10%

[0497] Initial load: 300g

[0498] Measurement interval: 1.5 points / ℃

[0499] [D Hardness]

[0500] The D hardness was determined according to JIS K6253. A D hardness tester manufactured by TECLOCK was used. For the test specimen, four overlaps were made of the endpoint detection windows (approximately 0.125 cm (1.25 mm) thick) described in Comparative Example B and Example B, with a total thickness of at least 0.45 cm (4.5 mm). It should be noted that the test specimens used were those that had been placed in a constant temperature and humidity bath at 20°C for 30 minutes.

[0501] [Evaluation B: Surface Quality Confirmation Test]

[0502] A polishing pad is placed at a specified position on the polishing apparatus through a double-sided adhesive tape with an acrylic adhesive, and a Cu film substrate is polished under the following conditions.

[0503] (Grinding conditions)

[0504] Grinding machine: F-REX300X (manufactured by Ebara Manufacturing Co., Ltd.)

[0505] Disk: A188 (manufactured by 3M)

[0506] Rotation speed: (platform) 85 rpm, (top ring) 86 rpm

[0507] Grinding pressure: 3.5 psi

[0508] Abrasive temperature: 20℃

[0509] Abrasive spray rate: 200ml / min

[0510] Abrasive: CSL-9044C (manufactured by FUJIMI CORPORATION) (CSL-9044C uses a mixture of concentrate and pure water at a weight ratio of 1:9)

[0511] Material to be ground: Cu film substrate

[0512] Grinding time: 60 seconds

[0513] Pad activation and operation: 35N for 10 minutes

[0514] Adjustments: Ex-situ, 35N, 4 scans

[0515] For the 10th to 50th pieces of the polished material after the above-mentioned grinding process, defects (surfscan SP2XP) larger than 155 nm were detected and evaluated using the high-sensitivity measurement mode of a surface inspection device (KLA-Tencor). Based on the confirmation results of the defects (surfscan), the surface quality was evaluated.

[0516] [Table 2]

[0517]

[0518] [Example C]

[0519] [Manufacturing Example C1: Endpoint Inspection Window C1]

[0520] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 90.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and 16.7 parts of glycerol were reacted to obtain a transparent component that serves as the endpoint detection window C1.

[0521] [Manufacturing Example C2: Endpoint Inspection Window C2]

[0522] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 103.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and 15.9 parts of glycerol were reacted to obtain a transparent component that serves as the endpoint detection window C2.

[0523] [Manufacturing Example C3: Endpoint Inspection Window C3]

[0524] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 78.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 650, 4.5 parts of glycerol, and 10.5 parts of ethylene glycol were reacted to obtain a transparent component that serves as the endpoint detection window C3.

[0525] [Example C1]

[0526] To 100 parts of a urethane prepolymer with an NCO equivalent of 420 obtained by reacting 2,4-toluene 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), 2.9 parts of unexpanded hollow microparticles (average particle size: 8.5 μm) formed from acrylonitrile-vinylidene chloride copolymer were added to obtain a polyurethane prepolymer mixture. The obtained urethane prepolymer mixture was loaded into a first liquid tank and kept at 60°C. Separately from the first liquid tank, 28.0 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylene bis(o-chloroaniline)) (MOCA) as a curing agent were added to a second liquid tank, heated to 120°C to melt and mix, and further degassed under reduced pressure to obtain a curing agent melt.

[0527] Next, the liquids from the first and second liquid tanks are injected into the respective inlets of a mixer equipped with two injection ports, and stirred to obtain a mixture.

[0528] The resulting mixture was then poured into a mold pre-set with the endpoint detection window C1 as described above, and cured once at 80°C for 30 minutes. The resulting block was removed from the mold and cured a second time in an oven at 120°C for 4 hours to obtain a polyurethane resin block. The obtained polyurethane resin block was then allowed to cool naturally to 25°C.

[0529] Then, after heating in an oven at 120°C for 5 hours, the material is sliced. The sliced ​​surfaces are then ground (polished) as needed to obtain a polyurethane foam sheet. Double-sided tape is then applied to the back of the polyurethane sheet to attach a buffer layer, and then double-sided tape is applied to the surface of the buffer layer to obtain a grinding pad.

[0530] It should be noted that when evaluating the cross-section around the endpoint detection window after the finishing process, the grinding pad obtained as described above is finished under the following conditions.

[0531] (Revision conditions)

[0532] Grinding machine used: Speedfam, product name "FAM-12BS"

[0533] Platform speed (grinding pad speed): 50 rpm

[0534] Flow rate: 100 ml / min (20°C pure water is dripped from the center of the rotating grinding pad.)

[0535] Dressing machine: A diamond dressing machine manufactured by 3M, model "A188".

[0536] Dressing machine speed: 100 rpm

[0537] Dressing pressure: 0.115 kg / cm 2

[0538] The dressing machine rotates in the same direction as the grinding pad.

[0539] Test duration: 60 minutes

[0540] [Example C2]

[0541] Except for using the endpoint detection window C2 of manufacturing example C3, the abrasive pad is obtained in the same manner as in example C1.

[0542] [Comparative Example C1]

[0543] Except for using the endpoint detection window C3 of manufacturing example C3, the abrasive pad is obtained in the same manner as in example C1.

[0544] [Pulse NMR]

[0545] Device: Minispec MQ20 ​​(manufactured by Bruker BioSpin Co., Ltd.)

[0546] Nuclear species: 1 H

[0547] Measurement: T2

[0548] Measurement method: Solid echo

[0549] Total number of times: 256

[0550] Repeat time: 1.0 second

[0551] Measurement temperature: 20℃, 80℃ (measurement begins 60 minutes after the device reaches the measurement temperature and the sample is set).

[0552] Under the aforementioned apparatus and conditions, Ten sample particles, approximately 50 mg each, were prepared and filled into a sample tube for pulse NMR measurement, thereby obtaining the attenuation curve.

[0553] The obtained decay curves were fitted and analyzed using Equation (1) to obtain the relaxation times of the crystalline phase, mesophase, and amorphous phase in the polyurethane resin. It should be noted that the fitting and analysis were performed using the software provided with the aforementioned measuring device.

[0554] M(t)=αexp(-(1 / 2)(t / T α ) 2 )sinbt / bt+βexp(-(1 / Wa)(t / T β ) Wa ) + γexp(-t / T γ Equation (1)

[0555] α: Composition fraction of the crystalline phase

[0556] T α Relaxation time of the crystalline phase (unit: msec)

[0557] β: Composition fraction of the intermediate phase

[0558] T β Relaxation time of the intermediate phase (unit: msec)

[0559] γ: Composition fraction of the amorphous phase

[0560] T γ Relaxation time of amorphous phase (unit: msec)

[0561] t: Observation time (unit: msec)

[0562] Wa: Shape factor

[0563] b: Shape factor

[0564] [Cross-section evaluation]

[0565] For each pad obtained as described above, the periphery of the endpoint detection window in the state after slicing and before trimming ( Figure 2 The part enclosed by the dashed line S) and (evaluation C1), the perimeter of the endpoint detection window of the adjusted state ( Figure 2 The cross section (evaluation C2) of the portion enclosed by the dashed line S was magnified 200 times within an area of ​​approximately 14 mm × 1 mm using a laser microscope (VK-X1000, KEYENCE). The observation was performed in connected mode, and the contour measurement of height information was performed based on the obtained laser image.

[0566] The results are shown in Figure 7A ~C、 Figure 8A ~C. It should be noted that, in Figure 7A ~C、 Figure 8A In ~C, the cross-sectional measurement results of the endpoint detection window at two points are shown. These results are obtained by measuring the cross-sections of each endpoint detection window in the slicing direction and in the direction perpendicular to the slicing direction.

[0567] In evaluation C1, if the distance between the endpoint detection window and the polished surface is within ±50μm, the evaluation is ○; otherwise, the evaluation is ×. In evaluation C2, a flat cross-sectional image (equal height from the end to the center) is ○, and a convex image (height increasing from the end to the center) is ×.

[0568] [Table 3]

[0569]

[0570] [Example D]

[0571] [Manufacturing Example D1: Endpoint Inspection Window D1]

[0572] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 90.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and 16.7 parts of glycerol were reacted to obtain a transparent component that serves as the endpoint detection window D1.

[0573] [Manufacturing Example D2: Endpoint Inspection Window D2]

[0574] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 103.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 1000 and 15.9 parts of glycerol were reacted to obtain a transparent component that became the endpoint detection window D2.

[0575] [Manufacturing Example D3: Endpoint Inspection Window D3]

[0576] 100 parts of 4,4'-methylenebis(cyclohexyl isocyanate), 78.6 parts of poly(oxytetramethylene) glycol (PTMG) with a number average molecular weight of 650, 4.5 parts of glycerol, and 10.5 parts of ethylene glycol were reacted to obtain a transparent component that serves as the endpoint detection window D3.

[0577] [Example D1]

[0578] To 100 parts of a urethane prepolymer with an NCO equivalent of 420 obtained by reacting 2,4-toluene 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), 2.9 parts of unexpanded hollow microparticles (average particle size: 8.5 μm) formed from acrylonitrile-vinylidene chloride copolymer were added to obtain a polyurethane prepolymer mixture. The obtained urethane prepolymer mixture was loaded into a first liquid tank and kept at 60°C. Separately from the first liquid tank, 28.0 parts of 3,3'-dichloro-4,4'-diaminodiphenylmethane (methylene bis(o-chloroaniline)) (MOCA) as a curing agent were added to a second liquid tank, heated to 120°C to melt and mix, and further degassed under reduced pressure to obtain a curing agent melt.

[0579] Next, the liquids from the first and second liquid tanks are injected into the respective inlets of a mixer equipped with two injection ports, and stirred to obtain a mixture.

[0580] Then, the obtained mixture is poured into a mold pre-set with the endpoint detection window D1 obtained as described above, and cured once at 80°C for 30 minutes. The formed block is removed from the mold and cured a second time in an oven at 120°C for 4 hours to obtain a polyurethane resin block. The obtained polyurethane resin block is then allowed to cool naturally to 25°C.

[0581] Then, after heating in an oven at 120°C for 5 hours, the material is sliced. The sliced ​​surfaces are then ground (polished) as needed to obtain a polyurethane foam sheet. Double-sided tape is then applied to the back of the polyurethane sheet to attach a buffer layer, and then double-sided tape is applied to the surface of the buffer layer to obtain a grinding pad.

[0582] [Dynamic Viscoelasticity Measurement]

[0583] Dynamic viscoelasticity was measured under the following conditions. First, the sample was immersed in water at 23°C for 3 days. Then, the obtained sample was used to perform dynamic viscoelasticity measurements in water (immersion state). It should be noted that the sample dimensions for the endpoint detection window were 5cm (length) × 0.5cm (width) × 0.13cm (thickness), and the sample dimensions for the abrasive layer were also 5cm (length) × 0.5cm (width) × 0.13cm (thickness).

[0584] (Measurement conditions)

[0585] Measurement apparatus: RSA G2 (manufactured by TA Instruments)

[0586] Test length: 1cm

[0587] Sample pretreatment: Keep in water at 23°C for 3 days.

[0588] Test mode: Tension

[0589] Frequency: 1.6Hz

[0590] Temperature range: 30~55℃

[0591] Heating rate: 0.3℃ / min

[0592] Strain range: 0.10%

[0593] Initial load: 300g

[0594] Measurement interval: 200 points / ℃

[0595] [Surface quality verification test]

[0596] A polishing pad is placed at a specified position on the polishing apparatus through a double-sided adhesive tape with an acrylic adhesive, and a Cu film substrate is polished under the following conditions.

[0597] (Grinding conditions)

[0598] Grinding machine: F-REX300X (manufactured by Ebara Manufacturing Co., Ltd.)

[0599] Disk: A188 (manufactured by 3M)

[0600] Rotation speed: (platform) 85 rpm, (top ring) 86 rpm

[0601] Grinding pressure: 3.5 psi

[0602] Abrasive temperature: 20℃

[0603] Abrasive spray rate: 200ml / min

[0604] Abrasive: CSL-9044C (manufactured by FUJIMI CORPORATION) (CSL-9044C uses a mixture of concentrate and pure water at a weight ratio of 1:9)

[0605] Material to be ground: Cu film substrate

[0606] Grinding time: 60 seconds

[0607] Pad activation and operation: 35N for 10 minutes

[0608] Adjustments: Ex-situ, 35N, 4 scans

[0609] For the 10th to 50th pieces of the polished material after the above-mentioned grinding process, defects (surfscan SP2XP) larger than 155 nm were detected and evaluated using the high-sensitivity measurement mode of a surface inspection device (KLA-Tencor). Based on the confirmation results of the defects (surfscan), the surface quality was evaluated.

[0610] [Table 4]

[0611]

[0612] It should be noted that the [p / w] ratio in Table 4 represents the ratio of the storage modulus E'w of the endpoint detection window to the storage modulus E'p of the polishing layer at the same temperature, or the ratio of tanδw of the endpoint detection window to tanδp of the polishing layer. 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, and the ratio (E'p40 / E'w40) of Comparative Example D1 is 4.90.

[0613] Additionally, in Table 4, [difference |pw|] represents the difference between the storage modulus E'w of the endpoint detection window and the storage modulus E'p of the grinding plate at the same temperature, or the difference between tanδw of the endpoint detection window and tanδp of the grinding plate. For example, according to Table 1, the difference (|tanδw30-tanδp30|) in Example D1 is 0.07, the difference (|tanδw30-tanδp30|) in Example D2 is 0.12, and the difference (|tanδw30-tanδp30|) in Comparative Example D1 is 0.34.

[0614] Industrial availability

[0615] The polishing pad of the present invention has industrial applicability as a pad suitable for polishing semiconductor wafers and the like.

[0616] Symbol Explanation

[0617] 10… Grinding pad, 11… Grinding layer, 11a… Grinding surface, 12… End point detection window, 13… Buffer layer, 14, 15… Adhesive layer, 16… Groove, 20… Grinding device, 21… Top ring, 22… Worktable, 23… Post-mold detection sensor, 24… Slurry, W… Wafer

Claims

1. An abrasive pad having an abrasive layer and an endpoint detection window provided in an opening of the abrasive layer. The abrasive layer comprises polyurethane resin P and hollow microparticles dispersed in the polyurethane resin P. The endpoint detection window comprises polyurethane resin WI. The polyurethane resin WI comprises structural units derived from alicyclic isocyanates and / or aliphatic isocyanates, structural units derived from compounds having three or more hydroxyl groups, and structural units derived from polyether polyols. In the dynamic viscoelasticity determination of the endpoint detection window conducted under tensile mode, frequency 1.0 Hz, and temperature range of 10–100 °C, the storage modulus E' at 90 °C was... W90 1.0×10 7 Pa or above The D hardness (D) at 80°C of the endpoint detection window W80 (40 or above) The D hardness (D) at 20°C of the endpoint detection window W20 The range is 40-90.

2. The abrasive pad as described in claim 1, wherein, In the dynamic viscoelasticity determination at the endpoint detection window, the storage modulus E' at 30°C W30 60×10 7 ~100×10 7 Pa.

3. The abrasive pad as described in claim 1 or 2, wherein, In the dynamic viscoelasticity measurement of the endpoint detection window, the peak temperature of tanδ is 70–100 °C.

4. An abrasive pad having an abrasive layer and an endpoint detection window provided in an opening of the abrasive layer. The abrasive layer comprises polyurethane resin P and hollow microparticles dispersed in the polyurethane resin P. The endpoint detection window comprises polyurethane resin WI. The polyurethane resin WI comprises structural units derived from alicyclic isocyanates and / or aliphatic isocyanates, structural units derived from compounds having three or more hydroxyl groups, and structural units derived from polyether polyols. In the dynamic viscoelasticity determination conducted under tensile conditions, a frequency of 1.0 Hz, and a temperature range of 10–100°C, the storage modulus E' at 30°C within the endpoint detection window was determined. W30 The energy storage modulus E' of the polishing layer at 30°C P30 The ratio (E') P30 / E' W30 The value ranges from 0.60 to 1.

50.

5. The abrasive pad as described in claim 4, wherein, In the dynamic viscoelasticity measurement, the storage modulus E' at 50°C of the endpoint detection window is... W50 The energy storage modulus E' of the polishing layer at 50°C P50 The ratio (E') P50 / E' W50 The range is 0.70 to 2.

00.

6. The abrasive pad as described in claim 4 or 5, wherein, In the dynamic viscoelasticity determination at the endpoint detection window, the storage modulus E' at 30°C W30 10×10 7 ~60×10 7 Pa.

7. The abrasive pad as described in claim 4 or 5, wherein, The D hardness (D) at 20°C of the endpoint detection window W20 The range is 40-70.

8. An abrasive pad having an abrasive layer and an endpoint detection window provided in an opening of the abrasive layer. The abrasive layer comprises polyurethane resin P and hollow microparticles dispersed in the polyurethane resin P. The endpoint detection window comprises polyurethane resin WI. The polyurethane resin WI comprises structural units derived from alicyclic isocyanates and / or aliphatic isocyanates, structural units derived from compounds having three or more hydroxyl groups, and structural units derived from polyether polyols. When the free induction decay curves of 1H spin-spin relaxation obtained by pulsed NMR using the Solid Echo method are separated into three curves representing the three components—crystalline phase, mesophase, and amorphous phase—in order of relaxation time from shortest to longest, the waveforms are analyzed. At 20°C, the ratio of the amorphous phase presence ratio Lw20 in the endpoint detection window to the amorphous phase presence ratio Lp20 in the polishing layer (Lp20 / Lw20) is 0.5 to 2.

0. At 80°C, the ratio of the presence ratio of the crystalline phase Sw80 in the endpoint detection window to the presence ratio of the crystalline phase Sp80 in the polishing layer (Sp80 / Sw80) is 0.5 to 2.

0.

9. The abrasive pad as claimed in claim 8, wherein, At 20°C, the ratio of the intermediate phase presence ratio Mw20 in the endpoint detection window to the intermediate phase presence ratio Mp20 in the polishing layer (Mp20 / Mw20) is 0.7 to 1.

5.

10. The abrasive pad as claimed in claim 8 or 9, wherein, At 80°C, the ratio of the intermediate phase presence ratio Mw80 in the endpoint detection window to the intermediate phase presence ratio Mp80 in the polishing layer (Mp80 / Mw80) is 0.5 to 1.

5.

11. The abrasive pad as claimed in claim 8 or 9, wherein, The difference between the existence ratio Lw20 and the existence ratio Lp20 (|Lp20-Lw20|) is less than 10.

12. The abrasive pad as claimed in claim 8 or 9, wherein, The difference between the presence ratio Sw80 and the presence ratio Sp80 (|Sp80-Sw80|) is 15 or less.

13. The abrasive pad as claimed in claim 8 or 9, wherein, The polyurethane resin P contains structural units derived from aromatic isocyanates.

14. A method for manufacturing a ground workpiece, comprising: A grinding process in which a workpiece is ground using the grinding pad according to any one of claims 1 to 13 in the presence of a grinding slurry to obtain a ground workpiece; and The endpoint detection process in this grinding process uses an optical endpoint detection method to perform endpoint detection.

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