Polishing pad, manufacturing method thereof, and manufacturing method of polished workpiece

Abstract

To provide a polishing pad which can impart good flatness to an object to be polished, and is excellent in compatibility with a slurry.SOLUTION: A polishing pad includes a resin sheet having a pore, in which in pore distribution of the resin sheet measured by a mercury press-in method at a contact angle of 130° and mercury surface tension of 485 dyn / cm, an integral pore volume V in a range of a pore size of 0.100 μm or more and 10.0 μm or less is 0.020 cm3 / g or more and 0.100 cm3 / g or less, and density of the resin sheet is 0.9 g / cm3 or more and 1.3 g / cm3 or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a polishing pad, a method for manufacturing the same, and a method for manufacturing a polished workpiece. [Background technology]

[0002] In general, polishing using a polishing pad is performed on materials such as optical materials such as lenses, plane-parallel plates, and reflecting mirrors, semiconductor wafers, semiconductor devices, substrates for hard disks, metals, and ceramics.

[0003] In polishing, various polishing pads have been developed for the purpose of improving the flatness of the polishing surface of the workpiece and the polishing rate of the polishing process. For example, Patent Document 1 describes a non-porous molded body of thermoplastic polyurethane, in which the maximum value of the loss tangent in the range of -70°C to -50°C is 4.00 × 10 -2 A polishing pad characterized by the following features has been disclosed. Patent Document 1 discloses that polishing using such a polishing pad suppresses the generation of burrs at the corners of recesses formed on the polishing surface.

[0004] Patent Document 2 describes a polishing pad having a polishing layer made of polyurethane resin foam having fine bubbles, in which the polyurethane resin foam contains a polyurethane resin having an Asker D hardness of 20 to 60 degrees and a specific wear parameter within a predetermined range, and further the number of bubbles is 200 / mm 2 Patent Document 2 discloses a polishing pad having a mean bubble diameter of 50 μm or less. Patent Document 2 discloses that such a polishing pad is less likely to scratch the surface of the workpiece, has excellent dressing properties, and has a higher polishing rate than conventional pads.

[0005] Patent Document 3 discloses a polishing pad for chemical mechanical polishing, which includes a porous foam having an average pore size of 50 μm or less, with 75% or more of the pores having a pore size within 20 μm of the average pore size, the porous foam containing a thermoplastic polyurethane as a polymer resin, and the thermoplastic polyurethane having predetermined physical properties. Patent Document 3 also discloses that such a polishing pad can impart excellent flatness to the polished surface of an object to be polished.

[0006] Patent Document 4 describes a polishing pad using a foam of polyurethane-based thermoplastic elastomer having a predetermined hardness, and the density of the foam is 0.2 to 1.3 g / cm 3 , the average cell diameter is 1 to 10 μm and the number of cells is 1 × 10 7 pieces / cm 3 A polishing pad characterized by the above is disclosed. Patent Document 4 discloses that such a polishing pad maintains a foamed state well and can impart excellent flatness to the polished surface of the workpiece. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6518680 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-111296 [Patent Document 3] Patent No. 4624781 [Patent Document 4] Patent No. 3649385 Summary of the Invention [Problem to be solved by the invention]

[0008] Generally, in the polishing process that requires high flatness, it is preferable to use a high-density polishing pad in order to make the sinking of the polishing pad moderate.On the other hand, the high-density polishing pad tends to have poor affinity with the slurry used in the polishing process.In the polishing pad, the affinity with the slurry is important from the viewpoint of improving the polishing rate and the flatness of the object to be polished.

[0009] The inventors have conducted a detailed study of conventional polishing pads, including those described in the above patent documents, and have found that conventional polishing pads at least have insufficient affinity with the slurry or provide insufficient flatness to the workpiece being polished.

[0010] For example, the non-porous polishing pad disclosed in Patent Document 1 has poor affinity with the slurry because the slurry does not easily penetrate into the polishing pad. Also, the polishing pads disclosed in Patent Documents 2 to 4 cannot provide sufficient flatness to the workpiece due to their low density, and also have poor affinity with the slurry.

[0011] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a polishing pad that can impart good flatness to the object to be polished and has excellent affinity with slurry, a method for manufacturing the same, and a method for manufacturing a polished object. [Means for solving the problem]

[0012] As a result of extensive research into solving the above problems, the present inventors have found that the above problems can be solved by using a resin sheet having predetermined physical properties, and have thus completed the present invention.

[0013] That is, the present invention includes the following aspects. [1] A polishing pad comprising a resin sheet having pores, In the pore distribution of the resin sheet measured by mercury intrusion porosimetry with a contact angle of 130° and a mercury surface tension of 485 dyn / cm, the cumulative pore volume V in the pore diameter range of 0.100 μm or more and 10.0 μm or less is 0.020 cm 3 / g or more 0.100cm 3 / g or less, The density of the resin sheet is 0.9 g / cm 3 More than 1.3g / cm 3 Below is the polishing pad. [2] In the pore distribution of the resin sheet, the cumulative pore volume V' in the pore diameter range of 0.050 μm or more and less than 0.100 μm is 0.000 cm 3 / g or more 0.120cm 3 / g or less. [3] The polishing pad according to [1] or [2], wherein in the pore distribution of the resin sheet, the ratio of the cumulative pore volume V to the cumulative pore volume V0 in the pore diameter range of 0.100 μm or more and 360 μm or less is 50% or more. [4] A polishing pad according to any one of [1] to [3], wherein in the pore distribution of the resin sheet, the ratio of the cumulative pore volume V to the cumulative pore volume V0' in the pore diameter range of 0.050 μm or more and 360 μm or less is 50% or more. [5] The polishing pad according to any one of [1] to [4], wherein in the pore distribution of the resin sheet, the peak position of the maximum peak in the pore diameter range of 0.100 μm or more and 360 μm or less is within the pore diameter range of 0.100 μm or more and 10.0 μm or less. [6] The polishing pad according to any one of [1] to [5], wherein in the pore distribution of the resin sheet, the peak position of the maximum peak in the pore diameter range of 0.050 μm or more and 360 μm or less is within the pore diameter range of 0.050 μm or more and 10.0 μm or less. [7] In the pore distribution of the resin sheet, the cumulative pore volume V0 in the pore diameter range of 0.100 μm or more and 360 μm or less is 0.040 cm3 / g or more 0.120cm 3 The polishing pad according to any one of [1] to [6], wherein the value is 0.1 / g or less. [8] In the pore distribution of the resin sheet, the cumulative pore volume V0' in the pore diameter range of 0.050 μm or more and 360 μm or less is 0.040 cm 3 / g or more 0.200cm 3 The polishing pad according to any one of [1] to [7], wherein the value is 0.1 / g or less. [9] The polishing pad according to any one of [1] to [8], wherein the resin sheet has a microphase separation structure.

[10] The polishing pad according to any one of [1] to [9], wherein the resin sheet contains polyurethane.

[11] A polishing pad comprising a resin sheet having pores, In the pore distribution of the resin sheet measured by mercury intrusion porosimetry with a contact angle of 130° and a mercury surface tension of 485 dyn / cm, the cumulative pore volume V'' in the pore diameter range of 0.050 μm or more and 10.0 μm or less is 0.020 cm 3 / g or more 0.140cm 3 / g or less, The density of the resin sheet is 0.9 g / cm 3 More than 1.3g / cm 3 Below is the polishing pad.

[12] A method for producing a polishing pad according to any one of [1] to

[11] , A method for producing a polishing pad, comprising the step of curing a mixed liquid of at least one prepolymer and at least two curing agents to obtain a resin sheet having a microphase-separated structure.

[13]

[12] The method for manufacturing a polishing pad according to

[12] , wherein the curing agent comprises a first curing agent having an NH2 equivalent of 100 or more and 300 or less, a second curing agent having an OH equivalent of 200 or more and 500 or less, and a third curing agent having an OH equivalent of 1000 or more and 2000 or less.

[14] A method for producing a polished product, comprising a polishing step of polishing a workpiece using the polishing pad according to any one of [1] to

[11] in the presence of a polishing slurry. [Effects of the Invention]

[0014] According to the present invention, it is possible to provide a polishing pad that can impart good flatness to the object to be polished and has excellent affinity with a slurry, a method for manufacturing the same, and a method for manufacturing a polished object. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 shows the results of measuring the cumulative pore volume (pore distribution) of the resin sheet of Example 1 by mercury intrusion porosimetry. [Figure 2] Fig. 2(A) is an SEM image of the surface of the resin sheet of Example 1, observed at 500x magnification using a scanning electron microscope. Fig. 2(B) shows the area in Fig. 2(A) where a microphase-separated structure (gyroid structure) was observed, surrounded by a dashed line. [Figure 3] FIG. 3 is an SEM image of the surface of the resin sheet of Example 2 observed with a scanning electron microscope at 500 magnifications. [Figure 4] FIG. 4 shows the results of measuring the cumulative pore volume (pore distribution) of the resin sheet of Comparative Example 1 by mercury porosimetry. [Figure 5] FIG. 5 is an SEM image of the surface of the resin sheet of Comparative Example 1 observed with a scanning electron microscope at 500 magnifications. DETAILED DESCRIPTION OF THE INVENTION

[0016] Below, we will explain in detail the embodiment of the present invention (hereinafter referred to as the ``present embodiment''), but the present invention is not limited to this and various modifications are possible within the scope of the gist of the present invention.

[0017] (Polishing pad) The polishing pad of this embodiment includes a resin sheet having pores, and in the pore distribution of the resin sheet measured by mercury porosimetry with a contact angle of 130° and a mercury surface tension of 485 dyn / cm, the cumulative pore volume V in the pore diameter range of 0.100 μm or more and 10.0 μm or less is 0.020 cm 3 / g or more 0.100cm 3 / g or less, and the density of the resin sheet is 0.9 g / cm 3 More than 1.3g / cm 3 The polishing pad of this embodiment is configured as described above, and therefore can impart good flatness to the object to be polished, and has excellent affinity with the slurry. The polishing pad of this embodiment can also be specified as follows from the viewpoint of the cumulative pore volume V' described below: That is, the polishing pad of this embodiment includes a resin sheet having pores, and in the pore distribution of the resin sheet measured by mercury porosimetry with a contact angle of 130° and a mercury surface tension of 485 dyn / cm, the cumulative pore volume V'' in the pore diameter range of 0.050 μm to 10.0 μm is 0.020 cm 3 / g or more 0.140cm 3 / g or less, and the density of the resin sheet is 0.9 g / cm 3 More than 1.3g / cm 3 The polishing pad of this embodiment specified in this way can also impart good flatness to the object to be polished and has excellent affinity with the slurry.

[0018] The polishing pad of this embodiment is not particularly limited as long as it includes the resin sheet of this embodiment, and the polishing pad may have a configuration other than the resin sheet. Examples of the configuration other than the resin sheet in the polishing pad include a polishing layer, a cushion layer, and an adhesive layer, which are conventionally known. In this specification, when referring to a "resin sheet in this embodiment," it means a resin sheet having pores, in which the cumulative pore volume V in the pore diameter range of 0.100 μm or more and 10.0 μm or less is 0.020 cm in the pore distribution of the resin sheet measured by mercury porosimetry with a contact angle of 130° and a mercury surface tension of 485 dyn / cm. 3 / g or more 0.100cm 3 / g or less, and the density of the resin sheet is 0.9 g / cm 3 More than 1.3g / cm 3 "A resin sheet having pores, the pore distribution of which is measured by mercury porosimetry with a mercury surface tension of 485 dyn / cm, and in which the cumulative pore volume V'' in the pore diameter range of 0.050 μm or more and 10.0 μm or less is 0.020 cm or less" and "A resin sheet having pores, the pore distribution of which is measured by mercury porosimetry with a mercury surface tension of 485 dyn / cm, and in which the cumulative pore volume V'' in the pore diameter range of 0.050 μm or more and 10.0 μm or less is 0.020 cm or less" 3 / g or more 0.140cm 3 / g or less, and the density of the resin sheet is 0.9 g / cm 3 More than 1.3g / cm 3 The term "resin sheet" as used herein includes both the resin sheet and the resin sheet.

[0019] The polishing pad of this embodiment preferably has the above-mentioned resin sheet as a polishing layer. "Having a resin sheet as a polishing layer" means that at least one surface of the polishing pad of this embodiment corresponds to the surface of the resin sheet of this embodiment, and the surface of the resin sheet becomes the polishing surface pressed against the polished object during polishing of this embodiment. Therefore, the polishing pad of this embodiment preferably has at least one surface made of the resin sheet of this embodiment. Moreover, the polishing pad of this embodiment may be made only of the resin sheet of this embodiment.

[0020] The polishing pad of this embodiment may have grooves, embossing, and / or holes (punching) on ​​the polishing surface as needed, and may also have a light-transmitting portion. The shape of the grooves and embossing is not particularly limited, and examples thereof include a lattice shape, a concentric circle shape, and a radial shape.

[0021] (resin sheet) (density) The resin sheet in this embodiment has a density of 0.9 g / cm 3 More than 1.3g / cm 3 The density of the resin sheet in this embodiment is 0.9 g / cm 3That is, when the resin sheet is high in density, the polishing pad is less likely to deform under pressure, so that the force applied from the polishing pad to the workpiece during polishing is uniform in the direction of the polishing surface. As a result, when a polishing pad having such a resin sheet is used for polishing, the polished surface of the workpiece can be made even flatter. In this specification, "the polished surface of the workpiece is flat" means that the polished surface of the workpiece is flatter overall. This can also be said to have good global flatness. From the same viewpoint, the density of the resin sheet in this embodiment is preferably 0.9 g / cm 3 more preferably 1.0 g / cm 3 More preferably, it is 1.1 g / cm or more. 3 The density of the resin sheet is 0.9 g / cm 3 "greater than" means that the density of the resin measured to two significant figures is 0.91 g / cm 3 This means that it is more than or equal to this. The density of the resin sheet in this embodiment is 1.3 g / cm 3 If the hardness is less than this, the hardness of the resin sheet tends to be low, and the occurrence of scratches tends to be suppressed during polishing using a polishing pad equipped with such a resin sheet. The density of the resin sheet in this embodiment can be measured by a conventionally known method. For example, the mass and volume of a resin sheet piece can be measured by a conventional method, and the density can be calculated from the obtained values. The method for controlling the density of the resin sheet is not particularly limited, but for example, a polishing pad can be obtained by the polishing pad manufacturing method of this embodiment described below. In particular, in the manufacturing process of the resin sheet in this embodiment, the density of the resin sheet can be increased by reducing the amount of foaming agent or not using a foaming agent.

[0022] (Pore distribution of resin sheet) (cumulative pore volume V) The resin sheet in this embodiment has pores, and in a pore distribution measured by mercury intrusion porosimetry with a contact angle of 130° and a mercury surface tension of 485 dyn / cm, the cumulative pore volume V in the pore diameter range of 0.100 μm or more and 10.0 μm or less is 0.020 cm 3 / g or more 0.100cm 3 / g or less. In the following description, unless otherwise specified, the term "pore distribution" refers to a pore distribution measured by mercury porosimetry with a contact angle of 130° and a mercury surface tension of 485 dyn / cm. Mercury porosimetry is a method for measuring the pore distribution on the surface of a sample by filling mercury into the pores on the surface of the sample while sweeping the applied pressure. Therefore, when measuring the pore distribution of a foamed material by mercury porosimetry, the pore distribution mainly reflects the pore distribution of interconnected cells (generally also referred to as "open cells"), and the contribution of the pore distribution of closed cells is small.

[0023] Regarding the polishing pad of this embodiment, the inventors have found that in the pore distribution measured by mercury intrusion porosimetry, the cumulative pore volume V in the pore diameter range of 0.100 μm or more and 10.0 μm or less is 0.020 cm 3 / g or more, the polishing pad has a sufficiently good affinity with the slurry. 3 / g or more, interconnected cells having a pore size of 0.100 μm or more and 10.0 μm or less are distributed throughout the resin sheet, and during polishing, the slurry penetrates uniformly into the resin sheet through the interconnected cells. However, when the cumulative pore volume V is 0.020 cm 3 The reason why the affinity of the polishing pad with the slurry is sufficiently good when the surface roughness is 1 / g or more is not limited to the above. From the viewpoint of further improving the affinity with the slurry, in the resin sheet of this embodiment, the cumulative pore volume V is preferably 0.030 cm 3 / g or more, and more preferably 0.040 cm 3 / g or more, and more preferably 0.050 cm3 / g or more. Furthermore, when the cumulative pore volume V is within the above range, the resin sheet has high density yet excellent dressability. Note that "dressing" or "dressing treatment" refers to a treatment of adjusting the surface roughness and flatness of the polishing surface of the polishing pad using a dressing jig (e.g., a diamond dresser or sandpaper) to which abrasive grains or the like are fixed before polishing the workpiece. Furthermore, "excellent dressability" means that a sufficient dressing treatment can be performed by treatment under relatively easy conditions. "Polishing surface" refers to the surface that the polishing pad contacts, or is expected to contact, with the workpiece when polishing the workpiece with the polishing pad. In the resin sheet of this embodiment, the cumulative pore volume V is 0.100 cm 3 / g or less. The cumulative pore volume V is 0.100 cm 3 / g or less, the density of the resin sheet tends to be within the above range, and in a polishing process using a polishing pad equipped with such a resin sheet, the polished surface of the workpiece can be made even smoother. From the same viewpoint, the cumulative pore volume V is preferably 0.090 cm 3 / g or less, and more preferably 0.080 cm 3 / g or less.

[0024] (cumulative pore volume V') In the pore distribution of the resin sheet in this embodiment, the cumulative pore volume V′ in the pore diameter range of 0.050 μm or more and less than 0.100 μm is typically 0.000 cm 3 / g or more 0.120cm 3 / g or less, and from the viewpoint of further improving the balance between the flatness imparted to the workpiece and the affinity with the slurry, it is preferably 0.000 cm 3 / g or more 0.100cm 3 / g or less, and more preferably 0.000cm 3 / g or more 0.080cm 3 / g or less. From the above viewpoint, the polishing pad of this embodiment is provided with a resin sheet having pores, and in the pore distribution of the resin sheet measured by mercury porosimetry with a contact angle of 130° and a mercury surface tension of 485 dyn / cm, the cumulative pore volume V″ in the pore diameter range of 0.050 μm or more and 10.0 μm or less is 0.020 cm 3 / g or more 0.140cm 3 / g or less, and the density of the resin sheet is 0.9 g / cm 3 More than 1.3g / cm 3 In this embodiment, the cumulative pore volume V'' in the pore diameter range of 0.050 μm or more and 10.0 μm or less can be specified as the sum of the cumulative pore volume V and the cumulative pore volume V' in this embodiment, and from the viewpoint of further improving the balance between the flatness imparted to the workpiece and the affinity with the slurry, it is preferable to specify a value of 0.020 cm 3 / g or more 0.140cm 3 / g or less, preferably 0.030 cm 3 / g or more 0.130cm 3 / g or less, and more preferably 0.050 cm 3 / g or more 0.120cm 3 / g or less.

[0025] (Ratio of cumulative pore volume V to cumulative pore volume V0) In the polishing pad of this embodiment, from the viewpoint of further improving the balance between the flatness imparted to the workpiece and the affinity with the slurry, in the pore distribution of the resin sheet, the ratio of the cumulative pore volume V in the pore diameter range of 0.100 μm to 10.0 μm to the cumulative pore volume V0 in the pore diameter range of 0.100 μm to 360 μm is preferably 50% or more. In other words, the ratio (V / V0) of the cumulative pore volume V to the cumulative pore volume V0 is preferably 0.50 or more. According to this embodiment, the resin sheet has an increased proportion of pores having relatively small pore diameters, so that the resin sheet can have a higher density while still having a higher number of interconnected cells. From the same viewpoint, the ratio of the integral pore volume V to the integral pore volume V0 is more preferably 60% or more, even more preferably 65% ​​or more, and even more preferably 70% or more. There is no particular upper limit to the ratio of the integral pore volume V to the integral pore volume V0, and the ratio of the integral pore volume V to the integral pore volume V0 may be 100% or less, 99% or less, 95% or less, 90% or less, or 80% or less. In the pore distribution of the resin sheet of this embodiment, the ratio (V / V') of the cumulative pore volume V to the cumulative pore volume V' in the pore diameter range of 0.050 μm to 360 μm is, from the same viewpoint as above, preferably 50% or more, more preferably 60% or more, even more preferably 65% ​​or more, and still more preferably 70% or more. Furthermore, V / V' may be 100% or less, 99% or less, 95% or less, 90% or less, or 80% or less.

[0026] (Peak position of the maximum peak) In the pore distribution of the resin sheet of this embodiment, the peak position of the maximum peak in the pore diameter range of 0.100 μm to 360 μm is preferably within the pore diameter range of 0.100 μm to 10.0 μm. Generally, in mercury intrusion porosimetry, the pore distribution is measured as the cumulative pore volume from the maximum pore diameter in the measurement range. Therefore, "the peak position of the maximum peak in the pore diameter range of 0.100 μm to 360 μm" refers to the position (pore diameter) of the maximum peak in the log differential pore volume distribution (dV / d(logD)) calculated from the pore distribution obtained by mercury intrusion porosimetry. Furthermore, when there are multiple maximum points in the pore diameter range of 0.100 μm to 360 μm, the maximum peak refers to the maximum point with the largest maximum value. By having the peak position of the maximum peak in the pore diameter range of 0.100 μm to 360 μm be within the pore diameter range of 0.100 μm to 10.0 μm, the resin sheet has pores with a more uniform distribution in the range of 0.100 μm to 10.0 μm, which tends to further improve the affinity with the polishing pad slurry and dressability. From the viewpoint of further improving the affinity with the polishing pad slurry and dressability, the peak position of the maximum peak in the pore diameter range of 0.100 μm to 360 μm is more preferably within the pore diameter range of 0.500 μm to 5.00 μm. Furthermore, in the pore distribution of the resin sheet in this embodiment, the peak position of the maximum peak in the pore diameter range of 0.050 μm or more and 360 μm or less is preferably within the pore diameter range of 0.050 μm or more and 10.0 μm or less, and more preferably within the pore diameter range of 0.050 μm or more and 5.00 μm or less.

[0027] (Number of peaks and peak height) In the pore distribution of the resin sheet in this embodiment, the number of peaks in the pore diameter range of 0.100 μm or more and 360 μm or less is preferably 1 or more and 3 or less, more preferably 1 or more and 2 or less, and even more preferably 1. When the number of peaks is within the above range, the pores have a more uniform distribution, which tends to further improve the affinity of the polishing pad with the slurry and the dressing ability. From a similar viewpoint, when there are two or more peaks in the pore diameter range of 0.100 μm or more and 360 μm or less, the peak height of the largest peak is preferably at least two times, more preferably at least five times, and even more preferably at least 10 times the peak height of the second highest peak.

[0028] (cumulative pore volume V0) In the pore distribution of the resin sheet in this embodiment, the cumulative pore volume V0 in the pore diameter range of 0.100 μm or more and 360 μm or less is preferably 0.040 cm 3 / g or more 0.120cm 3 / g or less, and more preferably 0.050 cm3 / g or more 0.110cm 3 / g or less, and more preferably 0.060 cm 3 / g or more 0.100cm 3 When the cumulative pore volume V0 is within the above range, the balance between the flatness imparted to the workpiece and the affinity with the slurry tends to be further improved. In addition, in the pore distribution of the resin sheet in this embodiment, the cumulative pore volume V0′ in the pore diameter range of 0.050 μm or more and 360 μm or less can be specified as the sum of the cumulative pore volume V0 and the cumulative pore volume V′ in this embodiment, and from the same viewpoint as above, it is preferably 0.040 cm 3 / g or more 0.200cm 3 / g or less, and more preferably 0.050 cm 3 / g or more 0.180cm 3 / g or less, and more preferably 0.060 cm 3 / g or more 0.160cm 3 / g or less.

[0029] In this embodiment, the cumulative pore volume V, the cumulative pore volume V', the cumulative pore volume V'', the cumulative pore volume V0, the cumulative pore volume V0' maximum peak peak position, the number of peaks, and the peak height values ​​are calculated from the pore distribution measured by mercury porosimetry with a contact angle of 130 ° and a mercury surface tension of 485 dyn / cm, but for more detailed measurement conditions of the mercury porosimetry, the method described in the Examples can be referenced. In addition, the cumulative pore volume V, the cumulative pore volume V', the cumulative pore volume V'', the cumulative pore volume V0, the cumulative pore volume V0' maximum peak peak position, the number of peaks, and the peak height values ​​are not particularly limited, but for example, a polishing pad may be obtained by the polishing pad manufacturing method of this embodiment described later.

[0030] (Structure of resin sheet) The resin sheet of this embodiment preferably has a microphase-separated structure. In this specification, the term "microphase-separated structure" refers to a phase-separated structure formed through microphase separation. Furthermore, in this specification, the term "microphase separation" refers to phase separation in which a microscopic (typically on the order of micrometers) structural pattern is repeated with at least one-dimensional periodicity in a macroscopically homogeneous object. Microphase separation can be achieved, for example, by employing preferred manufacturing conditions in the method for manufacturing a polishing pad of this embodiment, which will be described later. Typical examples of microphase-separated structures include, but are not limited to, a spherical structure (island-in-the-sea structure), a cylindrical structure, a lamellar structure, and a three-dimensional network structure. The microphase-separated structure of this embodiment preferably includes a cylindrical structure, a lamellar structure, and a three-dimensional network structure, and more preferably a three-dimensional network structure. In this specification, a three-dimensional network structure refers to a structure in which a mesh-like network is formed in three dimensions. The three-dimensional network structure derived from microphase separation may include a single gyroid structure and / or a double (multiple) gyroid structure. In this specification, a single gyroid structure typically refers to a network structure in which two twisted three-way branches combine to form a pair of thin wire structures, forming a unit cell, which is periodically repeated, and a double (multiple) gyroid structure refers to a structure in which two or more single gyroid structures are combined in a nested manner. In the cross section of a resin sheet having an open-cell structure resulting from conventional foaming agents or injecting an inert gas, a generally spherical foam cross section and flat resin regions (i.e., a sea-island structure of a resin sea and islands of voids) tend to be observed. On the other hand, when the resin sheet of the present embodiment has a double (multiple) gyroid structure, a phase-separated structure in which two or more resins are intertwined in a mottled pattern on the order of micrometers tends to be observed in the cross section. Furthermore, when the resin sheet of the present embodiment has a single gyroid structure, an amorphous void cross section and a resin skeleton / resin skeleton cross section are typically observed in the cross section. When the resin skeleton is sufficiently large compared to the voids, the resin skeleton may not be observable and the sheet may be observed as essentially a sea of ​​resin. However, even in this case, the voids in the resin sheet of the present embodiment are formed in a three-dimensional network-like interconnection. When a cross section of the resin sheet in this embodiment is observed, a mottled pattern of two or more resins, and characteristics of both an amorphous void cross section and a resin skeleton / resin skeleton cross section are observed. In other words, there are cases where the boundary between the double (multiple) gyroid structure and the single gyroid structure cannot be clearly distinguished, but in such cases, the resin sheet can be evaluated as including at least one of a single gyroid structure and a double (multiple) gyroid structure. Even when the resin sheet in this embodiment has a single gyroid structure and / or a double (multiple) gyroid structure, a sharp peak (maximum value) is typically measured in the pore diameter range of 0.100 μm or more and 10.0 μm or less in the Log differential pore volume distribution. Preferred structures observed in the polishing pad of this embodiment will be described in detail below, but it is assumed that each structure is derived from microphase separation.

[0031] The resin sheet of this embodiment may include two or more phases with different compositions. In this specification, the "composition" of a phase includes both the resin that is the main component of the phase and the components other than the main component contained in the phase, and further takes into consideration the blending ratio of these. Therefore, the microphase-separated structure of the resin sheet of this embodiment may include two or more phases in which at least one of the resin that is the main component of the phase and the components other than the main component contained in the phase are different from each other, and typically includes two or more phases in which at least one or more of the structure, average molecular weight, and functional group of the resin that is the main component of the phase are different.

[0032] Examples of two phases with different compositions include a case where the types of resins constituting one phase are different from those constituting the other phase; a case where the amount of additives contained in one phase is different from those constituting the other phase; and a case where the resin sheet is made of an AB block polymer, and one phase is a phase mainly composed of the A block and the other phase is a phase mainly composed of the B block.

[0033] Typical examples of microphase-separated structures containing two phases with different compositions include a first phase formed by the curing of a predetermined prepolymer and a predetermined curing agent, and a second phase formed by the curing of a prepolymer different from the prepolymer in the first phase and the curing agent in the first phase; a first phase formed by the curing of a predetermined prepolymer and a predetermined curing agent, and a second phase formed by the curing of a prepolymer in the first phase and a curing agent different from the curing agent in the first phase; and a first phase formed by the curing of a predetermined prepolymer and a predetermined curing agent, and a second phase formed by the curing of a prepolymer different from the prepolymer in the first phase and a curing agent different from the curing agent in the first phase.

[0034] The resin sheet in this embodiment may have voids resulting from microphase separation. Such voids may be referred to as voids constituting a microphase-separated structure, and specific examples thereof include, but are not limited to, voids defined by a resin skeleton that gives a gyroid structure. In this specification, the voids may be derived from pores or from interconnected pores formed by interconnecting a plurality of pores.

[0035] The resin sheet having the microphase separation structure of this embodiment can be obtained, for example, by the manufacturing method of the polishing pad of this embodiment described later. Furthermore, whether the resin sheet has the microphase separation structure can be confirmed by observing it with a scanning electron microscope (SEM) at a magnification of about 300 to 3000 times.

[0036] The fact that the resin sheet has a microphase separation structure containing two or more phases with different compositions or that it has the above-mentioned voids can be observed using optical methods such as an optical microscope and a phase contrast microscope, methods using electron microscopes such as a scanning electron microscope and a transmission electron microscope, methods using particle scattering such as light scattering, small-angle neutron scattering, and small-angle X-ray scattering, X-ray diffraction methods, fluorescence methods, and pulsed NMR measurement methods.

[0037] (average thickness of resin sheet) The average thickness of the resin sheet in this embodiment is not particularly limited, but is preferably 0.5 mm or more and 10.0 mm or less, more preferably 0.6 mm or more and 8.0 mm or less, and even more preferably 0.7 mm or more and 5.0 mm or less.

[0038] (Physical properties of resin sheet) The compressibility of the resin sheet in this embodiment is not particularly limited, but is preferably 0.1% or more and 10.0% or less, and more preferably 0.5% or more and 5.0% or less. The compressibility of the resin sheet can be determined using a Schopper-type thickness gauge (pressure surface: circular with a diameter of 1 cm) in accordance with Japanese Industrial Standards (JIS L 1021). Specifically, the thickness t0 is measured after applying an initial load from an unloaded state for 30 seconds, and then the thickness t1 is measured after applying a final pressure from the thickness t0 state for 30 seconds, and the compressibility can be calculated from the following formula. The initial load is 100 g / cm 2 , final pressure is 1120g / cm 2 is. Compression ratio (%) = 100 × (t0-t1) / t0

[0039] The compressive elastic modulus of the resin sheet in this embodiment is not particularly limited, but is preferably 65% ​​to 98%, more preferably 70% to 95%. The compressive elastic modulus of the resin sheet can be determined using a Schopper-type thickness gauge (pressure surface: circular, 1 cm diameter) in accordance with Japanese Industrial Standards (JIS L 1021). Specifically, the thickness t0 is measured after applying an initial load for 30 seconds from an unloaded state, then the thickness t1 is measured after applying a final pressure for 30 seconds from the thickness t0 state, and then all loads are removed from the thickness t1 state, the sheet is left for 5 minutes (unloaded state), and the thickness t0' is measured after applying the initial load again for 30 seconds, and the compressive elastic modulus can be calculated using the following formula. The initial load is 100 g / cm 2 , final pressure is 1120g / cm 2 is. Compressive elastic modulus (%) = 100 × (t0'-t1) / (t0-t1)

[0040] The Shore D hardness of the resin sheet in this embodiment is not particularly limited, but is preferably 30 or more and 90 or less, and more preferably 40 or more and 80 or less. The Shore D hardness of the resin sheet can be determined using a D-type hardness tester in accordance with Japanese Industrial Standards (JIS K 7311).

[0041] (Resin sheet material) The material of the resin sheet in this embodiment is not particularly limited. Examples of materials for the resin sheet include polyurethane resins. Examples of polyurethane resins include, but are not particularly limited to, polyester-based polyurethane resins, polyether-based polyurethane resins, and polycarbonate-based polyurethane resins. These may be used alone or in combination of two or more.

[0042] Among these, the material of the resin sheet in this embodiment preferably comprises at least one of polyester-based polyurethane resin and polyether-based polyurethane resin. In particular, it is preferable to comprise a polyurethane resin that is a cured product of a mixed solution containing a urethane prepolymer and at least two curing agents, as described later in the manufacturing method of the polishing pad of this embodiment. By using such a resin, it tends to be possible to easily make the density and pore size distribution within the above range.

[0043] The resin sheet of this embodiment may contain, in addition to the resin component, components derived from additives, such as antifoaming agents, catalysts, foaming agents, foam stabilizers, abrasive grains, dyes, pigments, solid fine particles, flame retardants, hydrophilizing agents, hydrophobic agents, light resistance agents, antioxidants, and antistatic agents, which will be described later in the method for producing a polishing pad of this embodiment.

[0044] [Polishing pad manufacturing method] The method for producing a polishing pad of this embodiment includes a step of obtaining a resin sheet having a microphase separation structure by curing a mixture of at least one prepolymer and at least two curing agents. According to this method, the polishing pad of this embodiment can be easily produced. Below, each step of the method for producing a polishing pad will be described in detail.

[0045] (Mixing process) The manufacturing method of the polishing pad of this embodiment can include a mixing step of preparing a mixture of at least one prepolymer and at least two curing agents.By using at least two curing agents in the mixing step, a resin sheet having a microphase separation structure can be obtained in the molding step after the mixing step.In particular, by using two or more curing agents to form a microphase separation structure, it is easier to control the curing reaction than when using two or more prepolymers to form a microphase separation structure, and the shape of the microphase separation structure tends to be easier to control.

[0046] In the mixing step, for example, at least one prepolymer and at least two curing agents heated to 30°C to 90°C are placed in a temperature-adjustable jacketed mixer and stirred at 30°C to 130°C. At this time, the mixed solution may be transferred to a tank with a jacket equipped with a stirrer and aged, if necessary. The stirring time is adjusted appropriately depending on the number of teeth, rotation speed, clearance, etc. of the mixer, but is, for example, 0.1 to 60 seconds.

[0047] (hardening agent) The curing agent used in the mixing step is not particularly limited, but examples thereof include amino group-containing compounds and hydroxyl group-containing compounds. Examples of the amino group-containing compound include, but are not particularly limited to, 4,4'-methylenebis(2-chloroaniline) (MOCA), ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, 4-methyl-2,6-bis(methylthio)-1,3-benzenediamine, 2-methyl-4,6-bis(methylthio)-1,3-benzenediamine, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 2,2-bis[3- Examples of the amino group-containing compound include 2,2-bis[3-(1-methylpropylamino)-4-hydroxyphenyl]propane, 2,2-bis[3-(1-methylpentylamino)-4-hydroxyphenyl]propane, 2,2-bis(3,5-diamino-4-hydroxyphenyl)propane, 2,6-diamino-4-methylphenol, trimethylethylenebis-4-aminobenzoate, and polytetramethyleneoxide-di-p-aminobenzoate. The amino group-containing compound is preferably 4,4'-methylenebis(2-chloroaniline).

[0048] The hydroxyl group-containing compound is not particularly limited, but examples thereof include ethylene glycol, propylene glycol, diethylene glycol, trimethylene glycol, tetraethylene glycol, triethylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-butanediol, 3-methyl-1,2-butanediol, 1,2-pentanediol, 1,4-pentanediol, 2,4-pentanediol, 2,3-dimethyltrimethylene glycol, and tetramethylene glycol. Examples of suitable hydroxyl group-containing compounds include glycol, 3-methyl-4,3-pentanediol, 3-methyl-4,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 1,5-hexanediol, 1,4-hexanediol, 2,5-hexanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, glycerin, trimethylolpropane, trimethylolethane, trimethylolmethane, polytetramethylene glycol, polyethylene glycol, and polypropylene glycol. From the viewpoint of controlling the reaction, it is preferable to use a bifunctional (diol) hydroxyl group-containing compound rather than a trifunctional or higher functional compound. Furthermore, polytetramethylene glycol is more preferred as the hydroxyl group-containing compound.

[0049] The curing agents may be used in combination of two or more. The combination of curing agents is not particularly limited, but the combinations described below are preferred.

[0050] The active hydrogen equivalent (e.g., NH equivalent and OH equivalent) of the curing agent is not particularly limited and may be, for example, 50 to 5,000, 100 to 4,000, or 130 to 3,000. The OH equivalent of a curing agent that is a hydroxyl group-containing compound may be 100 to 5,000, 200 to 4,000, or 300 to 3,000. The NH equivalent of a curing agent that is an amino group-containing compound may be 50 to 2,000, 75 to 1,000, or 100 to 300.

[0051] In the mixing step, at least two curing agents are used. It is preferable to use a combination of curing agents that have low compatibility with each other, and / or different reactivities, and / or different active hydrogen equivalents. This embodiment tends to more reliably obtain a microphase-separated structure. Examples of combinations of curing agents with different reactivities include combinations of curing agents with different active hydrogen groups, and more specifically, combinations of an amino group-containing compound and a hydroxyl group-containing compound.

[0052] When two or more curing agents having the same active hydrogen group are used, that is, when two or more hydroxyl group-containing compounds or two or more amino group-containing compounds are used, the two or more curing agents preferably include two curing agents whose difference in active hydrogen equivalent is 500 or more and 2000 or less. More preferably, the two or more curing agents include a curing agent whose active hydrogen equivalent is 200 or more and 500 or less and a curing agent whose active hydrogen equivalent is 1000 or more and 2000 or less.

[0053] When two or more curing agents having the same active hydrogen group are used, and the two or more curing agents include two curing agents whose difference in active hydrogen equivalent is 500 or more and 2000 or less, the ratio of the amount of the curing agent with the smaller active hydrogen equivalent to the amount of the curing agent with the larger active hydrogen equivalent, in terms of the ratio of the number of active hydrogen groups, "curing agent with the smaller active hydrogen equivalent:curing agent with the larger active hydrogen equivalent," is preferably 1:1 to 15:1, more preferably 1:1 to 10:1.

[0054] When two or more curing agents having the same active hydrogen group are used, and the two or more curing agents include one curing agent with an active hydrogen equivalent of 200 or more and 500 or less and another curing agent with an active hydrogen equivalent of 1000 or more and 2000 or less, the ratio of the amount of the curing agent with an active hydrogen equivalent of 200 or more and 500 or less to the amount of the curing agent with an active hydrogen equivalent of 1000 or more and 2000 or less, in terms of the number of active hydrogen groups, is preferably 1:1 to 15:1, and more preferably 1:1 to 10:1.

[0055] As a specific preferred combination of curing agents, the at least two curing agents preferably include an amino group-containing compound and a hydroxyl group-containing compound. The at least two curing agents more preferably include one amino group-containing compound and two or more hydroxyl group-containing compounds, or two or more amino group-containing compounds and one hydroxyl group-containing compound. The at least two curing agents even more preferably include one amino group-containing compound and two or more hydroxyl group-containing compounds.

[0056] When the at least two curing agents contain an amino group-containing compound and a hydroxyl group-containing compound, the difference between the NH equivalent of the amino group-containing compound and the OH equivalent of the hydroxyl group-containing compound is not particularly limited, but it is preferable that the OH equivalent of the hydroxyl group-containing compound is larger, and it is more preferable that the OH equivalent of the hydroxyl group-containing compound is larger by 100 or more and 2000 or less than the NH equivalent of the amino group-containing compound.

[0057] When the at least two types of curing agents include an amino group-containing compound and a hydroxyl group-containing compound, the ratio of the amount of the curing agent that is the amino group-containing compound used to the total amount of the curing agents used is preferably 35% or more and 95% or less, and more preferably 40% or more and 90% or less, in terms of the ratio of the number of functional groups.

[0058] An example of a preferred combination of curing agents includes at least two curing agents: a first curing agent (amino group-containing compound) having an NH equivalent of 100 to 300; a second curing agent (hydroxyl group-containing compound) having an OH equivalent of 200 to 600; and a third curing agent (hydroxyl group-containing compound) having an OH equivalent of 1000 to 2000. The ratio of the amounts of the first curing agent, second curing agent, and third curing agent used is not particularly limited, but the amount of the first curing agent used is preferably 30% to 95% and more preferably 40% to 90% in terms of the ratio of functional groups relative to the total amount of curing agents used. The amount of the second curing agent used is preferably 1% to 70% and more preferably 5% to 60% in terms of the ratio of functional groups relative to the total amount of curing agents used. The amount of the third curing agent used is preferably 3% or more and 60% or less, more preferably 5% or more and 50% or less, in terms of the ratio of the number of functional groups, to the total amount of the curing agents used.

[0059] Generally, the total amount of curing agent used is determined by the R value, which is the equivalent ratio of the active hydrogen groups (amino groups and hydroxyl groups) present in the curing agent when the number of functional groups in the prepolymer is taken as 1. The total amount of curing agent used is preferably adjusted so that the R value is 0.7 or more and 1.3 or less. The R value is more preferably 0.8 or more and 1.2 or less.

[0060] By using the above-mentioned preferred combination of curing agents in appropriate amounts, it is possible to more reliably measure the cumulative pore volume V in the pore diameter range of 0.100 μm to 10.0 μm inclusive, in a pore distribution measured by mercury intrusion porosimetry with a contact angle of 130° and a mercury surface tension of 485 dyn / cm, and to obtain a value of 0.020 cm 3 / g or more 0.100cm 3 / g or less, and / or a resin sheet having a microphase-separated structure can be obtained. As a combination of curing agents, two or more curing agents having low compatibility with each other, two or more curing agents having different reactivities, and / or curing agents having different active hydrogen equivalents can be used. Even if a resin sheet having a clear microphase-separated structure cannot be obtained by such a combination, a resin sheet having a microphase-separated structure tends to be obtained by adjusting the type of curing agent so that they are mutually compatible, changing the curing agent so that their reactivities are similar, and / or changing the curing agent so that their active hydrogen equivalents are close to each other.

[0061] (prepolymer) The prepolymer used in the mixing step is not particularly limited, but examples thereof include urethane prepolymers. Examples of urethane prepolymers include an adduct of hexamethylene diisocyanate and hexanetriol; an adduct of 2,4-tolylene diisocyanate and prenzcatechol; an adduct of 2,4-tolylene diisocyanate, poly(oxytetramethylene) glycol, and diethylene glycol; an adduct of tolylene diisocyanate and hexanetriol; an adduct of tolylene diisocyanate and trimethylolpropane; an adduct of xylylene diisocyanate and trimethylolpropane; an adduct of hexamethylene diisocyanate and trimethylolpropane; and an adduct of isocyanuric acid and hexamethylene diisocyanate. Other isocyanate group-containing compounds prepared by reacting a polyisocyanate compound with a polyol compound, as well as various commercially available urethane prepolymers, may also be used.

[0062] The polyisocyanate compound used in preparing the isocyanate group-containing compound is not particularly limited as long as it has two or more isocyanate groups in the molecule. For example, diisocyanate compounds having two isocyanate groups in the molecule include m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-tolylene diisocyanate (2,6-TDI), 2,4-tolylene diisocyanate (2,4-TDI), naphthalene-1,4-diisocyanate, diphenylmethane-4,4'-diisocyanate (MDI), 4,4'-methylene-bis(cyclohexyl isocyanate) (hydrogenated MDI), 3,3'-dimethoxy-4,4'-biphenyl diisocyanate, 3,3'-dimethyl ... Examples of the isocyanate include ethyldiphenylmethane-4,4'-diisocyanate, xylylene-1,4-diisocyanate, 4,4'-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene-1,2-diisocyanate, butylene-1,2-diisocyanate, cyclohexylene-1,2-diisocyanate, cyclohexylene-1,4-diisocyanate, p-phenylene diisothiocyanate, xylylene-1,4-diisothiocyanate, and ethylidine diisothiocyanate.

[0063] These polyisocyanate compounds may be used alone or in combination of two or more. As the polyisocyanate compound, a diisocyanate compound is preferred, and 2,4-TDI, 2,6-TDI, and MDI are more preferred.

[0064] Examples of polyol compounds used in preparing isocyanate group-containing compounds include diol compounds and triol compounds such as ethylene glycol, diethylene glycol (DEG), and butylene glycol; polyether polyol compounds such as polypropylene glycol (PPG) and poly(oxytetramethylene) glycol (PTMG); polyester polyol compounds such as the reaction product of ethylene glycol and adipic acid or the reaction product of butylene glycol and adipic acid; polycarbonate polyol compounds, and polycaprolactone polyol compounds. Trifunctional propylene glycol with added ethylene oxide can also be used. Polyol compounds may be used alone or in combination of two or more.

[0065] The NCO equivalent of the urethane prepolymer is preferably 150 or more and 700 or less, more preferably 200 or more and 600 or less, and even more preferably 200 or more and 500 or less. The "NCO equivalent" is a numerical value indicating the molecular weight of the urethane prepolymer per NCO group, calculated by (parts by mass of polyisocyanate compound + parts by mass of polyol compound) / [(number of functional groups per molecule of polyisocyanate compound × parts by mass of polyisocyanate compound / molecular weight of polyisocyanate compound) - (number of functional groups per molecule of polyol compound × parts by mass of polyol compound / molecular weight of polyol compound)].

[0066] In the mixing step, at least one prepolymer is used. Two or more of the above prepolymers may be used in combination, but preferably one prepolymer is used alone. According to such an embodiment, the curing reaction tends to be easily controlled, and the shape of the microphase-separated structure tends to be easily controlled. As the prepolymer, it is preferable to use a urethane prepolymer containing tolylene diisocyanate as the main component alone.

[0067] The amount of prepolymer used is not particularly limited, but is preferably 30 parts by mass or more and 80 parts by mass or less, and more preferably 40 parts by mass or more and 75 parts by mass or less, based on the total amount of the mixed liquid.

[0068] (additives) In the mixing step, components other than the prepolymer and the curing agent may be mixed as additives. Examples of additives include solvents (diluents) such as polypropylene glycol; antifoaming agents such as silicone-based antifoaming agents; catalysts; foaming agents such as water and hollow fine particles; foam stabilizers such as silicone-based foam stabilizers; and fillers (abrasive grains) such as cerium oxide; dyes; pigments; solid fine particles; flame retardants; hydrophilizing agents; hydrophobic agents; light-resistant agents; antioxidants; and antistatic agents. The density of the resulting resin sheet is 0.9 g / cm. 3 More than 1.3g / cm 3 From the viewpoints below, it is preferable to add no foaming agent or to add only a small amount of foaming agent, and it is more preferable to use an antifoaming agent.

[0069] In the mixing step, by adjusting the type and amount of catalyst added, the reaction rate of the curing reaction can be controlled, and the microphase-separated structure formed can be controlled.

[0070] (molding process) The molding step is a step of obtaining a resin sheet having a microphase-separated structure by curing the mixed liquid obtained as described above. For example, the molding step may involve pouring the mixed liquid obtained in the mixing step into a mold preheated to 30°C to 150°C and heating it at about 30°C to 150°C for about 10 minutes to 5 hours. This causes the prepolymer and the curing agent to react to form a resin, thereby curing the mixed liquid. Furthermore, secondary curing may be performed by heating in an oven at about 50°C to 180°C for about 10 minutes to 12 hours. In the method for producing a polishing pad according to this embodiment, since the mixed liquid is the above-described liquid, a resin block having a microphase-separated structure can be obtained.

[0071] The reaction temperature when curing the mixed solution in the molding step can be adjusted appropriately depending on the types and compounding ratios of the prepolymer, curing agent, and additives used, and adjusting the reaction temperature tends to control the reaction rate of the curing reaction and the microphase-separated structure that is formed.

[0072] In the molding process, a resin sheet having a microphase-separated structure is obtained by cutting a resin sheet of an appropriate thickness from the resin block obtained as described above. The obtained resin sheet may be aged at 30°C to 150°C for about 1 hour to 24 hours.

[0073] The resin sheet thus obtained has a double-sided tape attached to one side thereof, and is then cut into a predetermined shape, preferably a disk, to complete the polishing pad of this embodiment. The double-sided tape is not particularly limited, and any double-sided tape known in the art can be selected and used.

[0074] In addition, the polishing pad of this embodiment may have a single-layer structure consisting of only a resin sheet, or may have a multi-layer structure in which another layer (cushion layer or substrate layer) is attached to one side of the resin sheet. In the case of a multi-layer structure, the multiple layers may be bonded and fixed together using double-sided tape or adhesive, etc., while applying pressure as necessary. The double-sided tape and adhesive used are not particularly limited, and can be arbitrarily selected from conventionally known double-sided tapes and adhesives.

[0075] Furthermore, the polishing pad of this embodiment may have grooves, embossing, and / or holes (punching) on ​​the surface, as needed. The shapes of the grooves and embossing are not particularly limited, and examples thereof include lattice shapes, concentric circles, and radial shapes.

[0076] The polishing pad may also be dressed (grinded) on the front and / or back surface of the resin sheet. The resin sheet in the method for producing a polishing pad of this embodiment has high density but has interconnected pores, so it has excellent dressability and can be dressed under easy conditions. The dressing method is not particularly limited, and can be dressed by a known method such as grinding with a diamond dresser.

[0077] [Method of manufacturing polished products] The method for producing a polished product of this embodiment includes a polishing step of polishing a polished object using the above-mentioned polishing pad in the presence of a polishing slurry to obtain a polished product. The polishing step may be primary polishing (rough polishing), finish polishing, or both.

[0078] In the method for manufacturing a polished product according to this embodiment, the polishing slurry is supplied, and the holding platen and the polishing platen are rotated relative to each other while the polishing object is pressed against the polishing pad by the holding platen, so that the surface of the polished object is polished by the polishing pad through chemical mechanical polishing. The holding platen and the polishing platen may rotate in the same direction at different rotation speeds, or in different directions. Furthermore, the polished object may be polished while moving (rotating) inside the frame during the polishing process.

[0079] The polishing slurry may contain water, an oxidizing agent such as hydrogen peroxide, chemical components such as acid components and alkaline components, additives, and abrasive grains (abrasive particles; for example, SiC, SiO2, Al2O3, and CeO2), depending on the object to be polished and the polishing conditions.

[0080] The object to be polished is not particularly limited, but examples thereof include optical materials such as lenses, plane-parallel plates, and reflecting mirrors, semiconductor wafers, semiconductor devices, substrates for hard disks, metals, and ceramic materials. [Example]

[0081] The present embodiment will be described in more detail below using examples and comparative examples, but the present embodiment is not limited to the following examples.

[0082] [Measurement of cumulative pore volume (pore distribution) by mercury intrusion method] The cumulative pore volume (pore distribution) of the resin sheet was measured by mercury intrusion porosimetry. A 10 mm square sample was cut from a 2 mm thick resin sheet and used for the measurement. The cumulative pore volume was measured using a Micromeritics Auto Pore III under conditions of a contact angle of 130° and a mercury surface tension of 485 dyn / cm. The cumulative pore volume was calculated for pores with diameters ranging from 360 μm to 0.005 μm by sweeping the mercury pressure from 0.5 psia to 30,000 psia. The pore distribution was calculated using data processing software for porosimetry (Shimadzu Corporation, product name POREPLOT-PCW). The pore distribution for each measurement result is shown for pores with diameters ranging from 360 μm to 0.100 μm.

[0083] [Observation of resin sheet] Whether or not the resin sheet has a microphase-separated structure was confirmed by observation with a scanning electron microscope (SEM) at a magnification of about 300 to 3000 times.

[0084] [Example 1] A urethane prepolymer with an NCO equivalent weight of 407, mainly composed of 2,4-tolylene diisocyanate (TDI), was prepared.

[0085] 48.7 parts by weight of the above urethane prepolymer was mixed with 14.1 parts by weight of 4,4'-methylenebis(2-chloroaniline) (MOCA) (NH2 equivalent: 134), 5.7 parts by weight of polytetramethylene glycol (OH equivalent: 325), and 11.3 parts by weight of polypropylene glycol (OH equivalent: 1345). Furthermore, 0.25 parts by weight of a silicone antifoaming agent (DOW CORNING, product name "71additive"), 0.01 parts by weight of a catalyst (Tosoh Corporation, product name "Toyocat ET"), and 20.0 parts by weight of cerium oxide filler as abrasive grains were added to the above mixture to obtain a mixture that would serve as a resin sheet precursor. The R value of the mixture was 1.1.

[0086] The resulting mixture was poured into a mold preheated to 50°C and subjected to a primary cure at 50°C for 15 minutes. The resulting block-shaped molded product was removed from the mold and subjected to a secondary cure at 120°C for 8 hours in an oven to obtain a urethane resin block. The resulting urethane resin block was allowed to cool to 25°C and then sliced ​​to obtain a 2.0 mm thick resin sheet.

[0087] The density of the obtained resin sheet was 1.2 g / cm 3 The Shore D hardness was 54 degrees, the compressibility was 0.8%, and the compressive modulus was 85%. The measurement results of the pore distribution are shown in Figure 1. Table 1 also shows the cumulative pore volume V in the pore diameter range of 0.100 μm to 10.0 μm, the cumulative pore volume V' in the pore diameter range of 0.050 μm to less than 0.100 μm, the cumulative pore volume V0 in the pore diameter range of 0.100 μm to 360 μm, and the ratio V / V0, all of which were determined from the pore distribution.

[0088] Furthermore, when the surface of the resin sheet was observed with a scanning electron microscope, it was confirmed to have a microphase-separated structure (three-dimensional network structure). Specifically, a mottled structure in which at least two types of resin with different compositions were intertwined was observed, and it was evaluated to have at least a double gyroid structure. More specifically, an example of an SEM image is shown in Figure 2(A). As surrounded by dashed lines in Figure 2(B), a microphase-separated structure was confirmed in multiple locations.

[0089] [Example 2] A mixture of 54.0 parts by mass of the same urethane prepolymer as in Example 1, 9.6 parts by mass of 4,4'-methylenebis(2-chloroaniline) (MOCA) (NH2 equivalent 134), 22.9 parts by mass of polytetramethylene glycol (OH equivalent 325), 13.2 parts by mass of polypropylene glycol (OH equivalent 1345), 0.33 parts by mass of a silicone antifoaming agent (manufactured by DOW CORNING, product name "71additive"), and 0.01 parts by mass of a catalyst (manufactured by Tosoh Corporation, product name "Toyocat ET") was obtained as a precursor to the resin sheet. The R value of the mixture was 0.9.

[0090] The resulting mixture was poured into a mold preheated to 70°C and subjected to a primary cure at 70°C for 10 minutes. The resulting block-shaped molded product was removed from the mold and subjected to a secondary cure at 120°C for 15 minutes in an oven to obtain a urethane resin block. The resulting urethane resin block was allowed to cool to 25°C and then sliced ​​to obtain a 2.0 mm thick resin sheet.

[0091] The density of the obtained resin sheet was 1.1 g / cm 3 The Shore D hardness was 64 degrees, the compressibility was 1.3%, and the compressive modulus was 80%. The values ​​of the cumulative pore volume V, the cumulative pore volume V' in the pore diameter range of 0.050 μm or more and less than 0.100 μm, the cumulative pore volume V0, and the ratio V / V0 of the obtained resin sheet were 0.020 cm 3 / g or more 0.100cm 3 / g or less, 0.000cm 3 / g or more 0.120cm 3 / g or less, 0.040cm 3 / g or more 0.120cm 3 / g or less, and 50% or more. When the surface of the resin sheet was observed with a scanning electron microscope, no structure of resin sea and void islands was observed, and it was evaluated to have at least a single gyroid structure. An example of an SEM image is shown in Figure 3.

[0092] [Comparative Example 1] A first urethane prepolymer (NCO equivalent weight: 400) containing 2,4-tolylene diisocyanate (TDI) as a main component, and a second urethane prepolymer (NCO equivalent weight: 200) containing hexamethylene diisocyanate as a main component were prepared.

[0093] 51.6 parts by weight of the first urethane prepolymer and 17.2 parts by weight of the second urethane prepolymer were mixed with 23.3 parts by weight of 4,4'-methylenebis(2-chloroaniline) (MOCA) (NH2 equivalent: 134) and 4.7 parts by weight of polytetramethylene glycol (OH equivalent: 500). To the mixture, 1.39 parts by weight of polyether as a diluent, 1.67 parts by weight of a silicone antifoaming agent (Dow Corning, product name "71additive"), 0.04 parts by weight of a catalyst (Tosoh Corporation, product name "Toyocat ET"), 0.07 parts by weight of water as a foaming agent, and 0.10 parts by weight of a silicone foam stabilizer (Dow Corning Toray Co., Ltd., product name "SH193") were added to obtain a mixture that would serve as a precursor to the resin sheet. The R value of the mixture was 0.9.

[0094] The resulting mixture was poured into a mold preheated to 50°C and subjected to a primary cure at 50°C for 15 minutes. The resulting block-shaped molded product was removed from the mold and subjected to a secondary cure at 120°C for 8 hours in an oven to obtain a urethane resin block. The resulting urethane resin block was allowed to cool to 25°C and then sliced ​​to obtain a 2.0 mm thick resin sheet.

[0095] The density of the obtained resin sheet was 1.1 g / cm 3 The Shore D hardness was 69 degrees, the compressibility was 1.1%, and the compressive modulus was 90%. The measurement results of the pore distribution are shown in Figure 4. Table 1 also shows the cumulative pore volume V in the pore diameter range of 0.100 μm to 10.0 μm, the cumulative pore volume V0 in the pore diameter range of 0.100 μm to 360 μm, and the ratio V / V0, which were determined from the pore distribution.

[0096] Furthermore, when the surface of the resin sheet was observed with a scanning electron microscope, no microphase-separated structure was confirmed. An example of an SEM image is shown in Figure 5. In Comparative Example 1, it is believed that the desired curing reaction did not proceed and microphase separation did not occur due to at least a shortage of a curing agent having an OH equivalent of 1000 or more and 2000 or less.

[0097] [Table 1]

[0098] Polishing tests and tests to evaluate the affinity with the slurry were carried out using the polishing pads of Examples 1 and 2. As a control, polishing tests and tests to evaluate the affinity with the slurry were carried out under the same conditions using the polishing pad of Comparative Example 1. As a result, it was found that the polishing pads of the Examples can impart good flatness to the object to be polished and have excellent affinity with the slurry compared to the polishing pad of Comparative Example. [Industrial Applicability]

[0099] The polishing pad of the present invention has industrial applicability as a polishing pad used for polishing (particularly chemical mechanical polishing (CMP)) materials such as optical materials such as lenses, plane-parallel plates, and reflecting mirrors, semiconductor wafers, semiconductor devices, hard disk substrates, metals, and ceramics.

Claims

1. A polishing pad comprising a resin sheet having pores, In the pore distribution of the resin sheet measured by mercury intrusion porosimetry with a contact angle of 130° and a mercury surface tension of 485 dyn / cm, the cumulative pore volume V in the pore diameter range of 0.100 μm or more and 10.0 μm or less is 0.020 cm 3 / g or more 0.100cm 3 / g or less, The density of the resin sheet is 0.9 g / cm 3 1.3g / cm or more 3 Below is the polishing pad.

2. In the pore distribution of the resin sheet, the cumulative pore volume V′ in the pore diameter range of 0.050 μm or more and less than 0.100 μm is 0.000 cm 3 / g or more 0.120cm 3 2. The polishing pad of claim 1, wherein the surface roughness is 0.1 / g or less.

3. In the pore distribution of the resin sheet, the cumulative pore volume V in the pore diameter range of 0.100 μm or more and 360 μm or less 0 3. The polishing pad according to claim 1, wherein the ratio of the cumulative pore volume V to the total pore volume V is 50% or more.

4. In the pore distribution of the resin sheet, the cumulative pore volume V in the pore diameter range of 0.050 μm or more and 360 μm or less 0 4. The polishing pad according to claim 1, wherein the ratio of the cumulative pore volume V to the cumulative pore volume ' is 50% or more.

5. In the pore distribution of the resin sheet, the peak position of the maximum peak in the pore diameter range of 0.100 μm or more and 360 μm or less is in the pore diameter range of 0.100 μm or more and 10.0 μm or less. The polishing pad according to any one of claims 1 to 4.

6. In the pore distribution of the resin sheet, the peak position of the maximum peak in the pore diameter range of 0.050 μm or more and 360 μm or less is in the pore diameter range of 0.050 μm or more and 10.0 μm or less. The polishing pad according to any one of claims 1 to 5.

7. In the pore distribution of the resin sheet, the cumulative pore volume V in the pore diameter range of 0.100 μm or more and 360 μm or less 0 But 0.040 cm 3 / g or more 0.120cm 3 The polishing pad according to any one of claims 1 to 6, wherein the polishing pad has a surface roughness of 1 / g or less.

8. In the pore distribution of the resin sheet, the cumulative pore volume V in the pore diameter range of 0.050 μm or more and 360 μm or less 0 ' is 0.040 cm 3 / g or more 0.200cm 3 The polishing pad according to any one of claims 1 to 7, wherein the polishing pad has a surface roughness of 1 / g or less.

9. 9. The polishing pad according to claim 1, wherein the resin sheet has a microphase separation structure.

10. 10. The polishing pad according to claim 1, wherein the resin sheet contains polyurethane.

11. A polishing pad comprising a resin sheet having pores, In the pore distribution of the resin sheet measured by mercury intrusion porosimetry with a contact angle of 130° and a mercury surface tension of 485 dyn / cm, the cumulative pore volume V″ in the pore diameter range of 0.050 μm or more and 10.0 μm or less is 0.020 cm 3 / g or more 0.140cm 3 / g or less, The density of the resin sheet is 0.9 g / cm 3 1.3g / cm or more 3 Below is the polishing pad.

12. A method for producing the polishing pad according to any one of claims 1 to 11, comprising: A method for producing a polishing pad, comprising the step of curing a mixed liquid of at least one prepolymer and at least two curing agents to obtain a resin sheet having a microphase-separated structure.

13. The curing agent is NH 2 13. The method for producing a polishing pad according to claim 12, comprising: a first curing agent having an equivalent weight of 100 or more and 300 or less; a second curing agent having an OH equivalent weight of 200 or more and 500 or less; and a third curing agent having an OH equivalent weight of 1000 or more and 2000 or less.

14. 12. A method for producing a polished product, comprising a polishing step of polishing a workpiece with the polishing pad according to claim 1 in the presence of a polishing slurry.

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