Polishing pad, polishing device, article manufacturing method, and polishing pad manufacturing method

Abstract

To provide a polishing pad which can maintain high followability, because of preventing fluid from oozing out to a polishing surface even if the polishing pad is used in fluid supporting and polishing and a fluid pressure is added thereto.SOLUTION: There is provided a polishing pad 10 in which a polishing surface 11, a first region 12, a second region 13 and a sealing layer 14 are arranged in order. The first region 11 has first air bubbles 8A, and its hardness is first hardness. The second region 13 has second air bubbles 8B, and its hardness is second hardness smaller than the first hardness. Average air bubble density of the sealing layer 14 is lower than average air bubble densities of the first region 11 and the second region 12. The polishing pad 10 is composed of a resin molding.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a polishing pad, a polishing apparatus, a method for manufacturing an article, and a method for manufacturing a polishing pad. [Background technology]

[0002] The polishing pad is attached to a base and is used in polishing processes performed in the finishing process of semiconductor substrates and optical lenses. In polishing, it is required to finish the entire surface uniformly to eliminate unevenness in the thickness of the workpiece to be processed. Semiconductor substrates and optical lenses come in a wide variety of sizes, from a few mm to a few m. In the case of large sizes, due to warping of the workpiece to be processed, a part of the polishing pad may contact unevenly, making it difficult to finish uniformly. Therefore, it is required to improve the conformability of the polishing pad to the shape of the workpiece, eliminate uneven contact, and finish uniformly. As a method that is effective in improving conformability, a laminated polishing pad described in Patent Document 1 and a fluid support polishing described in Patent Document 2 are known.

[0003] A laminated polishing pad is a pad that has layers with different hardness and elasticity in the thickness direction within a single pad. The upper layer is a hard layer with high hardness to hold the slurry on the polishing surface, and the lower layer is a soft layer with low hardness to follow the warp of the workpiece. The advantage of such a laminated polishing pad is that it does not require bonding with an adhesive, so there is no deterioration in followability due to unevenness in the thickness of the adhesive.

[0004] Fluid support polishing is a processing method in which the support surface of the polishing pad is supported by a fluid, and the fluid is filled at a constant pressure to match the warp of the workpiece, so it has high followability. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2003-220550 A [Patent Document 2] JP 2004-358591 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, when a conventional laminated polishing pad is used for fluid support polishing, the fluid seeps out from the soft layer to which the fluid pressure is applied to the polishing surface, causing the fluid pressure to fluctuate and making it impossible to maintain high compliance. Also, when a sealing layer is attached to the laminated polishing pad with an adhesive, the unevenness in the thickness of the adhesive makes it impossible to maintain high compliance. [Means for solving the problem]

[0007] A polishing pad for solving the above problem is a polishing pad having a polishing surface, a first region, a second region, and a sealing layer arranged in this order, wherein the first region has first bubbles having a first hardness, the second region has second bubbles having a second hardness that is smaller than the first hardness, the sealing layer has an average bubble density lower than the average bubble densities of the first region and the second region, and the polishing pad is made of a resin molded body. Effect of the Invention

[0008] According to the present disclosure, a polishing pad can be provided that can maintain high conformability even when used in fluid support polishing and fluid pressure is applied, since the fluid does not seep out to the polishing surface. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic diagram of a polishing apparatus of the present disclosure. [Diagram 2] 2(a) and 2(b) are schematic diagrams of a polishing pad according to the present disclosure, in which (a) is a perspective view and (b) is a cross-sectional view taken along line AA in FIG. [Diagram 3] 4A to 4C are diagrams showing a manufacturing flow of the polishing pad according to the present disclosure. [Figure 4] Schematic diagram illustrating a manufacturing process for the polishing pad of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] [Polishing equipment] 1 is a schematic diagram of a polishing apparatus according to the present disclosure. The polishing apparatus 1 includes a polishing pad 10, a base 5 for fixing the polishing pad 10, a fluid storage section 6 for storing a fluid that applies pressure from the lower surface side (sealing layer side) of the polishing pad 10, and a supply section 2 for supplying a slurry S such as water or a polishing liquid to the polishing surface of the polishing pad 10. The polishing apparatus 1 is a wet-type polishing apparatus, and is an apparatus of the type in which the polishing pad is supported by a fluid.

[0011] The fluid reservoir 6 has a function of storing a liquid or gas, which is a fluid applied to the polishing pad 10 from the sealing layer side of the polishing pad 10 at a predetermined pressure. The type of fluid is not particularly limited, and gases include, for example, air, compressed air, and nitrogen. Liquids include, for example, pure water and polishing liquid. The magnitude of the pressure applied to the polishing pad 10 is not particularly limited as long as it is large enough to support the polishing pad 10, and is, for example, in the range of 3 kPa to 40 kPa. Preferably, it is in the range of 5 kPa to 20 kPa.

[0012] 1, a workpiece 3 to be processed is brought into contact with a polishing surface of a polishing pad 10 by a carrier workpiece 4 applying a force from above the workpiece 3. The workpiece 3 is, for example, a semiconductor substrate or an optical lens. In this specification, the workpiece 3 that has been polished is defined as an article.

[0013] [Polishing pad] 2 is a schematic diagram of a polishing pad according to the present disclosure, in which (a) is a perspective view, and (b) is an AA cross-sectional view taken along the line AA in the z-axis direction of (a) of FIG.

[0014] In FIG. 2, the plane horizontal to the polishing surface 11 is the xy plane, and the axis perpendicular to the xy plane is the z axis. The dashed line AA in FIG. 2(a) is parallel to the x axis and perpendicular to the y axis. The polishing pad 10 is arranged in the order of the first region 12, the second region 13, and the sealing layer 14 from the polishing surface 11 toward the negative z direction. The polishing pad 10 of the present disclosure has, from the side closer to the polishing surface 11, the hard first region 12 having a high hardness in order to reduce the roughness to be removed by polishing, the soft second region 13 having a low hardness that can follow the warp of the workpiece 3, and the sealing layer 14 for sealing the fluid pressure.

[0015] The polishing surface 11 is a portion of the polishing pad 10 that comes into contact with the workpiece 3. It is preferable that first bubbles 8A are arranged on the polishing surface 11. The arrangement of the first bubbles 8A enables the polishing surface 11 to store slurry S on its surface. If the polishing surface 11 can store slurry S, it becomes possible to supply the slurry S between the polishing pad 10 and the workpiece 3 during polishing even when the polishing pad 10 and the workpiece 3 are in contact with each other.

[0016] The first region 12 has the resin 7 and the first bubbles 8A, and has a first hardness. The surface of the first region 12 is the polishing surface 11, and by having a predetermined hardness, the first region 12 has a function of suppressing the polishing pad 10 from following the portion of the workpiece 3 to be polished, for example, a wavy portion having a high spatial frequency. The first hardness can be set to a desired hardness by controlling the amount of the first bubbles 8A (average bubble density). The first bubbles 8A can be made of the hollow portion of the first hollow particles. If the content of the first hollow particles is increased, the first hardness becomes smaller, and if the content of the first hollow particles is decreased, the first hardness becomes larger. However, if the first hardness is made too high, there is a risk that the deformation to follow the shape of the workpiece will not be sufficient. In order to increase the degree of freedom of deformation with respect to the workpiece and to prevent excessive following of the workpiece, it is preferable that the average bubble density of the first region 12 is in the range of 10% to 40%. A method for measuring the average bubble density will be described later. From the same viewpoint, the value of the first hardness is preferably in the range of 0.016 GPa to 0.06 GPa. The method for measuring the hardness will be described later.

[0017] The second region 13 has the resin 7 and the second bubbles 8B, and has a second hardness smaller than the first hardness. The second region 13 has a second hardness smaller than the first hardness, so that the polishing pad 10 can easily follow the shape of the workpiece 3. The second hardness can be set to a desired hardness by controlling the amount of the second bubbles 8B (average bubble density). The second bubbles 8B can use the hollow parts of the second hollow particles. When the content of the second hollow particles is increased, the second hardness becomes smaller, and when the content of the second hollow particles is decreased, the second hardness becomes larger. In order to make the second hardness smaller than the first hardness, it is preferable that the average bubble density of the second region 13 is higher than the average bubble density of the first region 12. In addition, since the average circle equivalent diameter of the second bubbles 8B is preferably larger than the average circle equivalent diameter of the first bubbles 8A, it is preferable that the average particle diameter of the second hollow particles is larger than the average particle diameter of the first hollow particles. Similarly, the linear expansion coefficient of the second hollow particles is preferably greater than the linear expansion coefficient of the first hollow particles. The second hardness is lower than the first hardness, and the greater the difference in hardness, the easier it is for the polishing pad 10 to conform to the shape of the workpiece 3. However, if the second hardness is too small, the reproducibility of polishing may deteriorate, and the possibility of damage to the workpiece 3 may increase depending on the material of the workpiece 3. Therefore, from the viewpoint of improving the conformability of the polishing pad 10 to the shape of the workpiece and ensuring the reproducibility of the polishing process, the average bubble density value of the second region 13 is preferably in the range of 40% to 80%. From the same viewpoint, the value of the second hardness is preferably in the range of 0.003 GPa to less than 0.016 GPa. In addition, in order to be able to conform to the warping of the workpiece 3, the thickness of the second region 13 (the length in the z direction in FIG. 2(b)) is preferably greater than the thickness of the first region 12 and the thickness of the sealing layer 14. More preferably, the thickness of the second region 13 is 1.5 times or more the thickness of the first region 12. More preferably, the thickness of the second region 13 is at least twice the thickness of the first region 12 .

[0018] The sealing layer 14 has the resin 7 and a support surface for the polishing pad, and its average bubble density is lower than the average bubble density of the first region 12 and the second region 13. The value of the average bubble density of the sealing layer 14 is not particularly limited, but is preferably 10% or less. If the average bubble density of the sealing layer 14 is too high, the bubbles tend to be connected. In that case, the fluid provided from the fluid storage section 6 may reach the workpiece 3 through the sealing layer 14, the second region 13, the first region 12, and the polishing surface 11. In addition, the hardness of the sealing layer 14 is preferably greater than the first hardness and the second hardness. The thickness of the sealing layer 14 (length in the z direction in FIG. 2(b)) is preferably smaller than the thickness of the first region 12 and the thickness of the second region 13.

[0019] The polishing pad 10 is a resin molded body. That is, the polishing surface 11, the first region 12, the second region 13, and the sealing layer 14 are molded integrally without the use of any adhesive. The raw material of the resin material which is the cured product constituting the resin molded body is not particularly limited, and for example, polyurethane, polyethylene, polypropylene, polystyrene, polyester, nylon, polyvinyl chloride, polyvinylidene chloride, polybutene, polyacetal, polyphenylene oxide, polyvinyl alcohol, polymethyl methacrylate, polysulfone, polyethersulfone, polyetherketone, polyetheretherketone, polyamideimide, polycarbonate, polyarylate, liquid crystal polymer, aromatic polysulfone resin, biodegradable polyester resin, polyamide resin, polyimide resin, fluororesin, ethylene-propylene resin, ethylene-ethyl acrylate resin, epoxy resin, acrylic resin, norbornene resin, styrene copolymer (for example, vinyl polyisoprene-styrene copolymer, butadiene-styrene copolymer, acrylonitrile-styrene copolymer, acrylonitrile-butadiene-styrene copolymer, etc.), natural rubber, synthetic rubber, and thermoplastic elastomer can be used. These exemplified resin materials may be used alone, or may be mixed or copolymerized. From the viewpoint of excellent abrasion resistance and facilitating the manufacturing process described later, it is preferable that polyurethane is the main component. In the present disclosure, the main component of a resin molded body refers to the component that contains the heaviest mass of the resin material when the resin molded body is composed of multiple resin materials. The proportion of polyurethane in the resin molded body is 50 mass% or more, preferably 70 mass% or more, and more preferably 90 mass% or more. The manufacturing method of the resin molded body will be described later.

[0020] The gas permeability of the polishing pad 10 is 50 ml / m 224 hr·atm or less is preferable. If the gas permeability is equal to or less than this value, even if the fluid is supplied from the fluid storage section 6 to the polishing pad 10, the polishing pad 10 will easily conform to the shape of the workpiece 3. On the other hand, if the gas permeability is greater than this value, the fluid pressure applied to the polishing pad may become too large, and the polishing pad 10 may have difficulty conforming to the shape of the workpiece 3. If the polishing pad 10 has difficulty conforming to the shape of the workpiece 3, the polishing process may not progress sufficiently, and the surface roughness of the workpiece 3 may not be sufficiently reduced.

[0021] The thickness of the polishing pad (the length in the z direction in FIG. 2(b)) is preferably in the range of 0.3 mm to 2.0 mm, because a thickness in this range allows the polishing pad 10 to easily conform to the warpage and shape of the workpiece 3.

[0022] As described above, the polishing pad of the present disclosure is composed of a resin molded body in which a polishing surface, a first region having a first hardness, a second region having a second hardness less than the first hardness, and a sealing layer are laminated in this order, so that even if a fluid pressure is applied when used for fluid-supported polishing, the fluid does not seep out to the polishing surface. In addition, since it is composed of a resin molded body that does not have an adhesive layer made of an adhesive, it can maintain high conformability to the shape and warping of the workpiece 3. Therefore, the polishing pad of the present disclosure can sufficiently reduce the surface roughness of the workpiece compared to conventional polishing pads for fluid-supported polishing.

[0023] In the present disclosure, an example in which the first cells 8A are smaller than the second cells 8B has been described, but the present invention is not limited to this as long as the second hardness of the second region 13 is smaller than the first hardness of the first region 12. In addition, if the polishing pad 10 is made of a resin molded body, another member may be provided on the lower surface of the sealing layer 14.

[0024] [Polishing pad manufacturing method] Next, a method for manufacturing the polishing pad will be described. Although the method for manufacturing the polishing pad 10 of the present disclosure is not particularly limited, a preferred embodiment will be described with reference to FIGS.

[0025] First, the first region precursor is placed in a mold and then heated to be provisionally cured (S1, FIG. 4(a)). The first region precursor 12A is a mixture containing a thermoplastic resin, a curing agent, and first hollow particles. The first region precursor 12A becomes the first region 12 of the polishing pad 10 after the main curing. The surface of the first region 12 becomes the polishing surface 11. The size and type of the mold 20 are not particularly limited, and it can be made to a desired size according to the shape of the polishing pad 10 to be manufactured. The mold 20 is, for example, a metal mold. In addition, when mixing the thermoplastic resin, the curing agent, and the first hollow particles, it is preferable to remove air bubbles using a defoamer or the like. The temperature of the provisional curing may be equal to or lower than the temperature of the main curing described later, and can be appropriately set depending on the material of the thermoplastic resin used. When the temperature of the provisional curing and the temperature of the main curing are the same, it is preferable that the time of the provisional curing is shorter than the time of the main curing.

[0026] Next, the second region precursor is placed on the first region precursor 12A provisionally cured in the mold, and then heated to provisionally cure (S2, FIG. 4(b)). The second region precursor 13A is a mixture containing a thermoplastic resin, a curing agent, and second hollow particles. The second region precursor 13A becomes the second region 13 of the polishing pad 10 after full curing. In addition, when mixing the thermoplastic resin, the curing agent, and the second hollow particles, it is preferable to remove air bubbles using a defoamer or the like. The temperature of the provisional curing may be lower than the temperature of the full curing described later, and can be appropriately set depending on the material of the thermoplastic resin used. The content and / or particle size of the second hollow particles are selected so that the second hardness of the second region 13 is smaller than the first hardness of the first region 12. The average particle size of the second hollow particles is preferably larger than the average particle size of the first hollow particles. In addition, the linear expansion coefficient of the second hollow particles is preferably larger than the linear expansion coefficient of the first hollow particles.

[0027] Next, the sealing layer precursor is placed on the second region precursor provisionally cured in the mold, and then heated to provisionally cure (S3, FIG. 4(c)). The sealing layer precursor 14A is a mixture containing a thermoplastic resin and a curing agent. After the sealing layer precursor 14A is fully cured, it becomes the sealing layer 14 of the polishing pad 10. In order to reduce the bubble density of the sealing layer 14, it is preferable that the sealing layer precursor 14A does not contain hollow particles. In addition, when mixing the thermoplastic resin and the curing agent, it is preferable to remove air bubbles using a defoamer or the like. The provisional curing temperature may be equal to or lower than the fully curing temperature described later, and can be appropriately set depending on the material of the thermoplastic resin used. When the provisional curing temperature and the fully curing temperature are the same, it is preferable that the provisional curing time is shorter than the fully curing time.

[0028] Then, the first region precursor, the second region precursor, and the sealing layer precursor are heated to fully cure (S4, FIG. 4(d)). The temperature for fully curing may be equal to or higher than the pre-curing temperature described above, and can be set appropriately depending on the thermoplastic resin material used. When the pre-curing temperature and the full curing temperature are the same, it is preferable that the full curing time is longer than the pre-curing time. After step S3, the pre-cured polishing pad precursor may be released from the mold 20 before being fully cured.

[0029] By the above steps, the polishing pad 10 of the present disclosure can be manufactured.

[0030] As described above, the manufacturing method of the polishing pad according to the present disclosure does not include a step of bonding the respective regions together using an adhesive, and instead performs integral molding, so that it is possible to provide a polishing pad that can maintain high conformability to the shape and warping of the workpiece 3. Thus, according to the manufacturing method of the polishing pad according to the present disclosure, it is possible to provide a polishing pad that can sufficiently reduce the surface roughness of the workpiece, compared to conventional polishing pads for fluid support polishing.

[0031] In the above-mentioned manufacturing method, the first region precursor, the second region precursor, and the sealing layer precursor are placed in the mold in this order, and then provisional curing and final curing are performed. However, the sealing layer precursor, the second region precursor, and the first region precursor may be placed in the mold in this order, and then provisional curing and final curing are performed. In the above-mentioned manufacturing method, the hardness of the first region 12 and the second region 13 is adjusted by the size or content of the hollow particles, but this is not limited to this embodiment. For example, the hardness of each of the first region precursor 12A and the second region precursor 13A may be controlled by intentionally foaming them when they are mixed. EXAMPLES

[0032] The present disclosure will be described more specifically below with reference to examples, but the present disclosure is not limited to the following examples.

[0033] Prior to the description of the Production Examples, the evaluation methods of the Examples and Comparative Examples will be described.

[0034] [Polishing pad evaluation method] (Indentation hardness) Measuring instrument: Nano Indenter (Toyo Corporation: Nano Indenter G200) Test method: Test pieces (φ70mm) were cut from the polishing pad according to the thickness to be evaluated, placed on the sample stage, and the indenter was set to a Berkovich and a pressing depth of 10μm in XR mode. Measurements were taken at 12 points per sample, and the average value was calculated.

[0035] (Gas permeability) Measuring device: Gas permeability test device Test method: A differential pressure gas chromatography method conforming to JIS K 7126-1 (differential pressure method) was used. One side of the test piece film (φ70 mm) was separated by a boundary, and test nitrogen gas was passed through it at atmospheric pressure, while the other side was subjected to reduced pressure. Measurements were taken three times for each sample, and the average value was calculated.

[0036] (Average bubble density) Measuring instrument: Color 3D laser microscope (Keyence: VK-9700) Test method: The cross section of the test piece (10 mm x 10 mm) was measured using a 10x objective lens, and then the resin and bubble areas were converted to grayscale using image processing and binarized at 125 gradations to calculate the average bubble density.

[0037] (Thickness) Measuring instrument: Color 3D laser microscope (Keyence: VK-9700) Test method: The cross section of the test piece (10 mm x 10 mm) was similarly measured with a 10x objective lens to measure the thickness of each layer.

[0038] (Workpiece roughness) Measuring instrument: White light interferometer (Zygo: CP300) Test method: A 5x objective lens was used to measure the stitching of a test workpiece (φ80mm) from a point moved 35mm to the left of the center to a point moved 35mm to the right of the center, and the Rz (JIS B 0601-2001) of the entire measured area was evaluated. The resolution was 0.01nm.

[0039] (Following ability) Test method: A workpiece made of a φ80mm glass substrate with a surface roughness of 50nmRz was polished for 30 minutes while adding cerium oxide (K30-9, manufactured by Mireiku Co., Ltd.) as a slurry, and the maximum roughness Rz was evaluated. At this time, the judgment value for whether the polishing pad was able to follow the workpiece was set to a maximum roughness of 1nmRz. This is because if the polishing pad does not follow the workpiece and is not able to polish it uniformly, unprocessed areas will remain and the roughness will not be below this judgment value. If the roughness is below 1nmRz, it is rated A, and if it is greater than 1nmRz, it is rated B.

[0040] [Polishing pad manufacturing] Example 1 The resin material was a thermoplastic polyurethane elastomer, Coronate 4370 (manufactured by Tosoh Corporation), and the curing agent was a polyol-based curing agent, Nipporan 4479 (manufactured by Tosoh Corporation). Matsumoto Microsphere F-80DE (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.) was used as the first hollow particles, and Matsumoto Microsphere FN-78D (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.), which has a larger linear expansion coefficient and particle size than the first hollow particles, was used as the second hollow particles.

[0041] The resin material, the hardener, and the first hollow particles were mixed, and the air bubbles were removed by a defoamer to obtain a first region precursor. The resin material, the hardener, and the second hollow particles were mixed, and the air bubbles were removed by a defoamer to obtain a second region precursor. The resin material and the hardener were mixed, and the air bubbles were removed by a defoamer to obtain a sealing layer precursor.

[0042] The first region precursor was placed in a square mold with a bottom surface of 200 × 200 mm, and provisionally cured in an electric furnace at 120 ° C for 10 minutes. Next, the second region precursor was placed on the provisionally cured first region precursor, and provisionally cured in an electric furnace at 120 ° C for 10 minutes. Then, the sealing layer precursor was placed on the provisionally cured second region precursor, and primary cured in an electric furnace at 120 ° C for 2 hours. Then, the provisionally cured polishing pad precursor was released from the mold. Then, the polishing pad precursor was secondary cured under the condition of 120 ° C for 8 hours to obtain the polishing pad of Example 1.

[0043] The polishing pad in Example 1 had a thickness of 1.5 mm, with the first region being 0.4 mm, the second region being 0.8 mm, and the sealing layer being 0.3 mm. The evaluation results of indentation hardness, gas permeability, bubble density, workpiece roughness, and conformability are summarized in Table 1. From Table 1, it was confirmed that in Example 1, the roughness was 1 nmRz or less, so that the polishing pad could conform sufficiently to the workpiece.

[0044] Example 2 In Example 2, the content of the second hollow particles is less than that in Example 1. Otherwise, the polishing pad of Example 2 was obtained by the same process as in Example 1. From Table 1, it was confirmed that the roughness in Example 2 was 1.0 nmRz or less, so that the polishing pad could sufficiently follow the workpiece. In addition, it was confirmed that the hardness of the second region was higher than that in Example 1, so that the roughness was larger.

[0045] Example 3 In Example 3, the content of the first hollow particles is greater than that in Example 1, and the content of the second hollow particles is less than that in Example 1. Otherwise, the polishing pad of Example 3 was obtained by the same process as in Example 1. From Table 1, it was confirmed that the roughness in Example 3 was 1.0 nmRz or less, so that the polishing pad could sufficiently follow the workpiece. In addition, it was confirmed that the roughness was greater because the hardness of the first region was lower and the hardness of the second region was higher than that in Example 1.

[0046] Example 4 In Example 4, the content of the first hollow particles is less than that in Example 3. Otherwise, the polishing pad of Example 4 was obtained by the same process as in Example 3. From Table 1, it was confirmed that the roughness in Example 4 was 1.0 nmRz or less, so that the polishing pad could sufficiently follow the workpiece. It was also confirmed that the roughness was reduced compared to Example 3 because the hardness of the first region was high.

[0047] Comparative Example 1 The resin material was a thermoplastic polyurethane elastomer, Coronate 4370 (manufactured by Tosoh Corporation), and the curing agent was Nipporan 4479 (manufactured by Tosoh Corporation). Matsumoto Microsphere F-80DE (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.) was used as the first hollow particle, and Matsumoto Microsphere FN-78D (manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd.), which has a larger linear expansion coefficient and particle size than the first hollow particle, was used as the second hollow particle.

[0048] The resin material, the curing agent, and the first hollow particles were mixed, and the air bubbles were removed by a defoamer to obtain a first molded body precursor. The resin material, the curing agent, and the second hollow particles were mixed, and the air bubbles were removed by a defoamer to obtain a second molded body precursor. The resin material and the curing agent were mixed, and the air bubbles were removed by a defoamer to obtain a sealing layer precursor.

[0049] The first molded body was obtained by placing the first molded body precursor in a square mold having a bottom surface of 200×200 mm, and curing it for 10 minutes in an electric furnace at 120° C. The thickness was 0.4 mm.

[0050] The second molded body was obtained by placing the second molded body precursor in a square mold having a bottom surface of 200×200 mm, and curing it for 10 minutes in an electric furnace at 120° C. The thickness was 0.8 mm.

[0051] Then, the first molded body and the second molded body were bonded with an adhesive (Cemedine 575F) to obtain an adhesive body. Then, a nitrile rubber sheet having a thickness of 0.3 mm was bonded to the second molded body side of this adhesive body with an adhesive. When bonding, a spatula was used to bond the first molded body and the second molded body, respectively, spreading them thinly and evenly while bonding them to obtain the polishing pad of Comparative Example 1.

[0052] Roughness was evaluated in the same manner as in Example 1. From Table 1, the roughness was greater than 1.0 nmRz in Comparative Example 1. This is thought to be because there was uneven adhesion when attaching the polishing pad and the rubber sheet, and the polishing pad was unable to follow the workpiece, making it impossible to perform uniform polishing.

[0053] Comparative Example 2 Comparative Example 2 is different from Example 3 in that the sealing layer precursor was not put into the mold and in that the thickness of the second region was different. Otherwise, the polishing pad of Comparative Example 2 was obtained by the same process as Example 3. The polishing pad had a thickness of 1.5 mm, with the first region being 0.4 mm and the second region being 1.1 mm. From Table 1, the roughness of Comparative Example 2 was greater than 1.0 nmRz. This is thought to be because the gas permeability was high and the fluid pressure leaked out above the threshold, making it impossible to follow the workpiece and causing the polishing process to not proceed sufficiently, resulting in high roughness.

[0054] [Table 1]

[0055] From the above results, it was confirmed that the polishing pad of the present disclosure is made of a resin molded body in which a polishing surface, a first region having a first hardness, a second region having a second hardness less than the first hardness, and a sealing layer are laminated in this order, so that even if fluid pressure is applied when used for fluid-supported polishing, the fluid does not seep out to the polishing surface. In addition, since it is made of a resin molded body without an adhesive layer made of an adhesive, it can maintain high conformability to the shape and warping of the workpiece. Therefore, it was found that the polishing pad of the present disclosure can sufficiently reduce the surface roughness of the workpiece compared to conventional polishing pads for fluid-supported polishing.

[0056] It should be noted that the present disclosure is not limited to the above-described embodiments, and many modifications are possible within the technical concept of the present disclosure. Furthermore, the effects described in the embodiments are merely a list of the most preferable effects resulting from the present disclosure, and the effects of the present disclosure are not limited to those described in the embodiments.

[0057] The disclosure of this embodiment includes the following configurations and methods.

[0058] (Configuration 1) 1. A polishing pad comprising, in order, a polishing surface, a first region, a second region, and a sealing layer, the first region has first bubbles and has a first hardness; the second region has second bubbles and has a second hardness that is less than the first hardness; the sealing layer has an average cell density lower than the average cell densities of the first region and the second region; The polishing pad is made of a resin molded body. A polishing pad characterized by:

[0059] (Configuration 2) The gas permeability of the polishing pad is 50 ml / m2 2. The polishing pad according to claim 1, wherein the resistance to atmospheric pressure is 24 hr·atm or less.

[0060] (Configuration 3) 3. The polishing pad of claim 1 or 2, wherein the second region has a higher average cell density than the first region.

[0061] (Configuration 4) The first region has an average cell density in the range of 10% to 40%; 4. The polishing pad according to claim 3, wherein the average cell density in the second region is in the range of 40% to 80%.

[0062] (Configuration 5) 5. The polishing pad according to any one of configurations 1 to 4, wherein the average equivalent circular diameter of the second cells is larger than the average equivalent circular diameter of the first cells.

[0063] (Configuration 6) 6. The polishing pad of any one of configurations 1 to 5, wherein the sealing layer has an average bubble density of 10% or less.

[0064] (Configuration 7) 7. The polishing pad of any one of configurations 1 to 6, wherein the hardness of the sealing layer is greater than the first hardness and the second hardness.

[0065] (Configuration 8) 8. The polishing pad according to any one of claims 1 to 7, wherein the polishing pad is mainly composed of polyurethane.

[0066] (Configuration 9) A polishing pad according to any one of configurations 1 to 8, wherein the thickness of the polishing pad in the direction in which the polishing surface, the first region, the second region, and the sealing layer are arranged in order is in the range of 0.3 mm or more and 2.0 mm or less.

[0067] (Configuration 10) 10. The polishing pad of any one of claims 1 to 9, wherein the second region is thicker than the first region and the sealing layer.

[0068] (Configuration 11) 11. The polishing pad according to any one of configurations 1 to 10, wherein the first hardness is in the range of 0.016 GPa or more and 0.06 GPa or less.

[0069] (Configuration 12) 12. The polishing pad according to claim 11, wherein the second hardness is in the range of 0.003 GPa or more and less than 0.016 GPa.

[0070] (Configuration 13) An apparatus for polishing a workpiece by placing the workpiece on the polishing surface of the polishing pad according to any one of configurations 1 to 12, comprising: A base for fixing the polishing pad; a fluid reservoir for storing a fluid that applies pressure to the polishing pad from the sealing layer side.

[0071] (Method 1) A method for manufacturing an article by polishing the workpiece using the polishing apparatus according to aspect 13 to manufacture an article.

[0072] (Method 2) A method for producing a polishing pad according to any one of claims 1 to 12, comprising the steps of: a step of placing a first region precursor having a thermoplastic resin, a curing agent, and first hollow particles in a mold and then heating the first region precursor to temporarily cure the first region precursor; placing a second region precursor having the thermoplastic resin, the curing agent, and second hollow particles on the provisionally cured first region precursor in the mold and then heating the second region precursor to provisionally cure; a step of placing a sealing layer precursor having the thermoplastic resin and the curing agent on the provisionally cured second region precursor in the mold and then heating the sealing layer precursor to provisionally cure; heating the first region precursor, the second region precursor, and the sealing layer precursor to fully cure them to form a first region, a second region, and a sealing layer; A method for manufacturing a polishing pad comprising the steps of:

[0073] (Method 3) The method for producing a polishing pad according to Method 2, wherein the average particle diameter of the second hollow particles is larger than the average particle diameter of the first hollow particles.

[0074] (Method 4) The method for producing a polishing pad according to Method 2 or 3, wherein the second hollow particles have a larger linear expansion coefficient than the first hollow particles.

[0075] (Method 5) A method for producing a polishing pad according to any one of claims 1 to 12, comprising the steps of: A step of placing a sealing layer precursor having a thermoplastic resin and a curing agent in a mold and then heating the sealing layer precursor to temporarily cure the sealing layer precursor; a step of placing a second region precursor having the thermoplastic resin, the curing agent, and second hollow particles on the provisionally cured sealing layer precursor in the mold and then heating the second region precursor to provisionally cure; a step of placing a first region precursor having the thermoplastic resin, the curing agent, and first hollow particles on the provisionally cured second region precursor in the mold and then heating the first region precursor to provisionally cure; heating the sealing layer precursor, the second region precursor, and the first region precursor to fully cure and form a sealing layer, a second region, and a first region; A method for manufacturing a polishing pad comprising the steps of: [Explanation of symbols]

[0076] 7. Resin 8A bubble (first bubble) 8B bubble (second bubble) 10 Polishing Pad 11 Polished surface 12 First area 13 Second area 14 Sealing layer 20-inch

Claims

1. 1. A polishing pad comprising, in order, a polishing surface, a first region, a second region, and a sealing layer, the first region has first bubbles and has a first hardness; the second region has second bubbles and has a second hardness that is less than the first hardness; the sealing layer has an average cell density lower than the average cell densities of the first region and the second region; The polishing pad is made of a resin molded body. A polishing pad characterized by:

2. The gas permeability of the polishing pad is 50 ml / m ２ The polishing pad according to claim 1, wherein the pressure is 24 hr·atm or less.

3. 2. The polishing pad of claim 1, wherein the average cell density in the second region is higher than the average cell density in the first region.

4. The first region has an average cell density in the range of 10% to 40%; 4. The polishing pad according to claim 3, wherein the average cell density in the second region is in the range of 40% to 80%.

5. The polishing pad according to claim 1 , wherein an average equivalent circular diameter of the second cells is larger than an average equivalent circular diameter of the first cells.

6. 2. The polishing pad of claim 1, wherein the sealing layer has an average cell density of 10% or less.

7. 2. The polishing pad of claim 1, wherein the hardness of the sealing layer is greater than the first hardness and the second hardness.

8. The polishing pad according to claim 1 , wherein the polishing pad is primarily made of polyurethane.

9. 2. The polishing pad according to claim 1, wherein the thickness of the polishing pad in the direction in which the polishing surface, the first region, the second region, and the sealing layer are arranged in order is in the range of 0.3 mm to 2.0 mm.

10. The polishing pad of claim 1 , wherein the second region is thicker than the first region and the sealing layer.

11. 2. The polishing pad according to claim 1, wherein the first hardness is in the range of 0.016 GPa or more and 0.06 GPa or less.

12. The polishing pad according to claim 11 , wherein the second hardness is in the range of 0.003 GPa or more and less than 0.016 GPa.

13. 13. An apparatus for polishing a workpiece by placing the workpiece on the polishing surface of the polishing pad according to claim 1, comprising: A base for fixing the polishing pad; a fluid reservoir for storing a fluid that applies pressure to the polishing pad from the sealing layer side.

14. A method for manufacturing an article, comprising polishing the workpiece using the polishing apparatus according to claim 13 to manufacture the article.

15. A method for producing a polishing pad according to any one of claims 1 to 12, comprising the steps of: a step of placing a first region precursor having a thermoplastic resin, a curing agent, and first hollow particles in a mold and then heating the first region precursor to temporarily cure the first region precursor; placing a second region precursor having the thermoplastic resin, the curing agent, and second hollow particles on the provisionally cured first region precursor in the mold and then heating the second region precursor to provisionally cure; A step of placing a sealing layer precursor having the thermoplastic resin and the curing agent on the provisionally cured second region precursor in the mold and then heating the sealing layer precursor to provisionally cure; heating the first region precursor, the second region precursor, and the sealing layer precursor to fully cure them to form a first region, a second region, and a sealing layer; A method for manufacturing a polishing pad comprising the steps of:

16. The method for producing a polishing pad according to claim 15 , wherein an average particle size of the second hollow particles is larger than an average particle size of the first hollow particles.

17. The method for producing a polishing pad according to claim 15 , wherein the linear expansion coefficient of the second hollow particles is greater than the linear expansion coefficient of the first hollow particles.

18. A method for producing a polishing pad according to any one of claims 1 to 12, comprising the steps of: A step of placing a sealing layer precursor having a thermoplastic resin and a curing agent in a mold and then heating the sealing layer precursor to temporarily cure the sealing layer precursor; a step of placing a second region precursor having the thermoplastic resin, the curing agent, and second hollow particles on the provisionally cured sealing layer precursor in the mold and then heating the second region precursor to provisionally cure; a step of placing a first region precursor having the thermoplastic resin, the curing agent, and first hollow particles on the provisionally cured second region precursor in the mold and then heating the first region precursor to provisionally cure; heating the sealing layer precursor, the second region precursor, and the first region precursor to fully cure and form a sealing layer, a second region, and a first region; A method for manufacturing a polishing pad comprising the steps of:

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