Pressure-sensitive adhesive sheet for fixing polishing pad, pressure-sensitive adhesive sheet for fixing polishing pad with release sheet, polishing pad with pressure-sensitive adhesive layer a, polishing pad with release sheet and pressure-sensitive adhesive layer a, method for fixing polishing pad to surface plate, and method for producing pressure-sensitive adhesive sheet for fixing polishing pad with release sheets fa and fb

Abstract

To provide a double-sided pressure-sensitive adhesive sheet for fixing a polishing pad to a surface plate, which is a pressure-sensitive adhesive sheet for fixing a polishing pad for high-precision CMP processing, is easy to adjust a re-sticking position, is excellent in air release properties, and is also excellent in pressure-sensitive adhesive properties.SOLUTION: A pressure-sensitive adhesive sheet for fixing a polishing pad to a surface plate, comprising a pressure-sensitive adhesive layer A on one surface of a sheet-shaped base material and a pressure-sensitive adhesive layer B on the other surface of the sheet-shaped base material, wherein a surface of the pressure-sensitive adhesive layer A not in contact with the sheet-shaped base material has irregularities, and in a Bekk smoothness test, a smoothness of the surface determined under the following condition 1 is 1 to 100 seconds and a smoothness of the surface determined under the following condition 2 is 15 to 1125 seconds: Condition 1: Time to change from - 50. 7kPa to - 48. 0kPa. Condition 2: Time to change from - 50. 7kPa to - 29. 3kPa.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an adhesive sheet for fixing a polishing pad to a surface plate. The present invention also relates to an adhesive sheet with a release sheet, in which an adhesive layer for fixing a polishing pad to a surface plate is covered with a release sheet. The present invention also relates to a polishing pad with an adhesive layer, which has a specific adhesive layer and a polishing pad. The present invention also relates to a polishing pad with a release sheet and an adhesive layer, which has a release sheet, a specific adhesive layer, and a polishing pad. The present invention also relates to a method for fixing a polishing pad to a surface plate via a specific adhesive layer. [Background technology]

[0002] Recent developments in semiconductors have required higher integration and higher quality, and therefore higher polishing precision is also required for the wafers that are the raw materials.In addition to simple abrasive excavation, there are also polishing methods such as CMP (Chemical Mechanical Polishing), which utilize chemical reactions to alter only the surface.In CMP as well, development of methods to obtain even smoother polished surfaces than before is progressing. A double-sided adhesive sheet is used to attach the polishing pad to the surface plate. Specifically, one side of the double-sided adhesive sheet is attached to one side of the polishing pad (the side opposite to the side intended to polish the object to be polished), and a polishing pad with a single-sided adhesive layer is prepared in advance, and the adhesive layer of the polishing pad with the single-sided adhesive layer is attached to the surface plate.

[0003] Various adhesive sheets for fixing polishing pads have been proposed (Patent Documents 1 to 3, etc.). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-122069 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-168714 [Patent Document 3] Japanese Patent Application Laid-Open No. 2012-057135 Summary of the Invention [Problem to be solved by the invention]

[0005] Various polishing pads are required depending on the stage of polishing, and polishing pads used for final polishing in particular have increasingly complex structures, with layers of various hardness and thicknesses. The more complex the polishing pad structure, the more difficult it becomes to attach the polishing pad to the surface plate. When attaching a polishing pad with a thick, highly multi-layered single-sided adhesive layer to a surface plate, achieving the desired position often requires a series of repositioning adjustments: temporary attachment, confirmation of the position, removal, and reattachment. From the perspective of improving productivity, it is desirable to minimize the number of repositioning adjustments required and to shorten the time as much as possible. In terms of ease of repositioning adjustments, using an adhesive layer with low adhesive strength is effective. However, the adhesive layer used to secure the polishing pad to the surface plate must have strong adhesive strength and cohesion (holding power) sufficient to withstand polishing.

[0006] Furthermore, even if a polishing pad with a single-sided adhesive layer can be quickly temporarily fixed to the desired position on the surface plate, there is a problem of air getting trapped between the surface plate and the adhesive layer when the polishing pad is firmly fixed to the surface plate using a roller or press. If air gets trapped between the surface plate and the adhesive layer and remains locally, the parallelism between the outermost surface of the polishing pad and the surface of the surface plate is lost, making it impossible to polish the object to be polished smoothly with high precision, which affects the polishing accuracy. One way to prevent air entrapment is to create grooves on the surface of the adhesive layer that comes into contact with the surface platen to allow air to pass through. However, even if air channels are created, when the polishing pad is firmly fixed to the surface platen, the soft adhesive layer can block the air channels, making it impossible to completely remove voids, or if it takes a long time for the air to escape, slowing down the semiconductor production speed.

[0007] The adhesive layer of the adhesive sheet that makes up the double-sided adhesive sheet used to secure the polishing pad to the surface plate must have strong adhesive strength, cohesive strength (holding power) that can withstand the shear force applied during the polishing process, and chemical resistance, such as strong alkali resistance and strong acid resistance, to the polishing solution used during polishing. In particular, strong alkaline resistance is highly required because CMP often uses strong alkaline polishing solutions.

[0008] The present invention has been made in consideration of the above background, and aims to provide a double-sided adhesive sheet for fixing a polishing pad to a base plate, which is intended for high-precision CMP processing and is easy to adjust the position when reattached, has excellent air release properties, and has excellent adhesive properties. [Means for solving the problem]

[0009] The present invention has solved the above problems by setting the smoothness of the adhesive layer on the side that is attached to the surface plate within a predetermined range. That is, the present invention relates to the following [1] to

[14] .

[0010] [1] The present invention provides an adhesive sheet for fixing a polishing pad to a surface plate, the adhesive sheet comprising an adhesive layer A on one side of a sheet-like substrate and an adhesive layer B on the other side of the sheet-like substrate, the surface of the adhesive layer A not in contact with the sheet-like substrate having irregularities, and in a Beck smoothness test: The surface smoothness determined by the following condition 1 is 1 to 100 seconds, The surface smoothness determined by the following condition 2 is 15 to 1125 seconds. The present invention relates to an adhesive sheet for fixing a polishing pad, characterized in that: Condition 1: Time required for pressure to change from -50.7kPa to -48.0kPa. Condition 2: Time required for pressure to change from -50.7kPa to -29.3kPa.

[0011] [2] The present invention relates to the adhesive sheet for fixing a polishing pad according to [1], wherein the average height Rc of the surface irregularities of the adhesive layer A is 10 to 40 μm. [3] The present invention relates to an adhesive sheet for fixing a polishing pad according to [1] or [2], characterized in that the cut level difference Rδc of the contour curve of the surface irregularities of the adhesive layer A is 5 to 25 μm, and the kurtosis Rku is less than 3. [4] The present invention relates to the pressure-sensitive adhesive sheet for fixing a polishing pad according to any one of [1] to [3] above, wherein the shape of the convex portions on the surface of the pressure-sensitive adhesive layer A in plan view is irregular and shapeless. [5] The present invention relates to the adhesive sheet for fixing a polishing pad according to any one of [1] to [4] above, wherein the adhesive layer A is an acrylic adhesive layer.

[0012] [6] The present invention provides an adhesive sheet for fixing a polishing pad with a release sheet FA, comprising the adhesive sheet for fixing a polishing pad according to any one of [1] to [5] above and a release sheet FA, The release sheet FA contacts the adhesive layer A, This relates to an adhesive sheet for fixing a polishing pad with a release sheet FA, characterized in that the material of the release sheet FA is a plastic film that does not contain paper.

[0013] [7] In the present invention, the surface of the adhesive layer B that is not in contact with the sheet-like substrate is in contact with the release sheet FB, The adhesive sheet for fixing a polishing pad with the release sheet FA and release sheet FB according to [6] above is characterized in that the material of the release sheet FB is a plastic film that does not contain paper.

[0014] [8] The present invention relates to a roll-shaped adhesive sheet for fixing a polishing pad with a release sheet FA as described in [6] above, which is wound into a roll and has a width direction length of 1000 mm or less, or to a roll-shaped adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB as described in [7] above, which is wound into a roll and has a width direction length of 1000 mm or less.

[0015] [9] The present invention relates to an adhesive sheet for fixing a polishing pad, comprising the release sheet FA and the release sheet FB according to [7] above, the short side of which has a length of 1000 mm or less.

[0016]

[10] The present invention provides a polishing pad with an adhesive layer, comprising a polishing pad and the adhesive sheet for fixing a polishing pad according to any one of [1] to [5] above, The polishing pad has an adhesive layer A, and the adhesive layer B is in contact with the polishing pad.

[0017]

[11] A polishing pad with an adhesive layer, comprising a polishing pad and an adhesive sheet for fixing the polishing pad with the release sheet FA described in [6] above, The polishing pad is provided with a release sheet FA and an adhesive layer A, in which the polishing pad and the adhesive layer B are in contact with each other.

[0018]

[12] This relates to a method for fixing a polishing pad to a surface plate via an adhesive sheet, characterized in that the release sheet FA is peeled off from the polishing pad with the release sheet FA and adhesive layer A described in

[11] above, and the adhesive layer A is attached to the surface plate.

[0019]

[13] A method for producing an adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB, the adhesive sheet comprising a release sheet FA, an adhesive layer A, a sheet-like substrate, an adhesive layer B, and a release sheet FB, The method comprises the following steps (1) to (4): (1) A step of applying adhesive a to the surface of a release sheet FA that has been subjected to a release treatment and has an average height Rc of the irregularities on the surface of 12 to 42 μm, thereby forming an adhesive layer A. (2) A step of superposing a sheet-like substrate on the surface of the adhesive layer A that is not in contact with the release sheet FA. (3) A step of applying adhesive b to the release-treated surface of the release sheet FB to form an adhesive layer B. (4) A step of superposing the surface of the adhesive layer B that is not in contact with the release sheet FB on the surface of the sheet-like substrate that is not in contact with the adhesive layer A. The surface of the adhesive layer A that is not in contact with the sheet-like substrate has irregularities, and in a Beck smoothness test, The surface smoothness determined by the following condition 1 is 1 to 100 seconds, The surface smoothness determined by the following condition 2 is 15 to 1125 seconds. This relates to a method for manufacturing an adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB. Condition 1: Time required for pressure to change from -50.7kPa to -48.0kPa. Condition 2: Time required for pressure to change from -50.7kPa to -29.3kPa.

[0020]

[14] A method for producing an adhesive sheet for fixing a polishing pad with release sheets FA and FB, comprising a release sheet FA, an adhesive layer A, a sheet-like substrate, an adhesive layer B, and a release sheet FB, The method comprises the following steps (5) to (8): (5) A step of applying adhesive a to one surface of the sheet-like substrate to form adhesive layer A. (6) A step of superposing the surface of the adhesive layer A that is not in contact with the sheet-like substrate on the surface of a release sheet FA having a release-treated surface with an average height Rc of irregularities of 12 to 42 μm. (7) A step of applying adhesive b to the release-treated surface of the release sheet FB to form an adhesive layer B. (8) A step of overlapping the surface of the adhesive layer B that is not in contact with the release sheet FB onto the surface of the sheet-like substrate that is not in contact with the adhesive layer A. The surface of the adhesive layer A that is not in contact with the sheet-like substrate has irregularities, and in a Beck smoothness test, The surface smoothness determined by the following condition 1 is 1 to 100 seconds, The surface smoothness determined by the following condition 2 is 15 to 1125 seconds. This relates to a method for manufacturing an adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB. Condition 1: Time required for pressure to change from -50.7kPa to -48.0kPa. Condition 2: Time required for pressure to change from -50.7kPa to -29.3kPa.

[0021]

[15] A method for producing an adhesive sheet for fixing a polishing pad with release sheets FA and FB, comprising a release sheet FA, an adhesive layer A, a sheet-like substrate, an adhesive layer B, and a release sheet FB, the method comprising the following steps (9) to (12): (9) A step of applying adhesive b to the release-treated surface of the release sheet FB to form an adhesive layer B. (10) A step of superposing a sheet-like substrate on the surface of the adhesive layer B that is not in contact with the release sheet FB. (11) A step of forming an adhesive layer A by applying an adhesive a to the surface of a release sheet FA which has been subjected to a release treatment and has an average height Rc of the irregularities on the surface of 12 to 42 μm. (12) A step of overlapping the surface of the adhesive layer A that is not in contact with the release sheet FA onto the surface of the sheet-like substrate that is not in contact with the adhesive layer B. The surface of the adhesive layer A that is not in contact with the sheet-like substrate has irregularities, and in a Beck smoothness test, The surface smoothness determined by the following condition 1 is 1 to 100 seconds, The surface smoothness determined by the following condition 2 is 15 to 1125 seconds. This relates to a method for manufacturing an adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB. Condition 1: Time required for pressure to change from -50.7kPa to -48.0kPa. Condition 2: Time required for pressure to change from -50.7kPa to -29.3kPa. [Effects of the Invention]

[0022] The present invention provides a double-sided pressure-sensitive adhesive sheet for fixing a polishing pad to a surface plate, which is easy to adjust the position for repositioning, has excellent air release properties, and is also excellent in adhesive properties and chemical resistance, such as resistance to strong alkalis and strong acids. The pressure-sensitive adhesive sheet for fixing a polishing pad of the present invention can improve workability during application and can significantly improve polishing accuracy in high-precision CMP processing. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic cross-sectional view showing an embodiment of an adhesive sheet for fixing a polishing pad and its usage. [Figure 2] FIG. 1 is a schematic diagram for explaining a Beck smoothness test. [Figure 3] 1 is an image diagram illustrating the unevenness (cross section) of the surface of adhesive layer A. FIG. [Figure 4] 1 is an image diagram illustrating the unevenness (cross section) of the surface of adhesive layer A. FIG. [Figure 5] 1 is an example of an image illustrating the unevenness of the surface of adhesive layer A. [Figure 6] 1 is an image diagram for explaining the unevenness (plan view) of the surface of adhesive layer A. FIG. [Figure 7] 1 is a cross-sectional schematic diagram showing an example of a method for manufacturing an adhesive sheet for fixing a polishing pad, and a usage form of the adhesive sheet for fixing a polishing pad. [Figure 8] FIG. 1 is a schematic diagram for explaining a method for evaluating lamination workability. [Figure 9] FIG. 2 is a schematic diagram illustrating a method for evaluating air release properties. DETAILED DESCRIPTION OF THE INVENTION

[0024] An example of an embodiment to which the present invention is applied will be described below. Note that in this specification, the numerical values ​​"A to B" indicate a numerical value of A or more and B or less.

[0025] <Adhesive sheet for fixing polishing pads> As shown in Figure 1-1, the adhesive sheet 1 for fixing a polishing pad of the present invention (hereinafter also referred to as adhesive sheet) comprises an adhesive layer A and an adhesive layer B on both sides of a sheet-like substrate F. Note that in Figure 1, the irregularities on the surface of adhesive layer A are not shown. In order to protect the surface of adhesive layer A (the side not in contact with sheet-like substrate F), the surface of adhesive layer A is covered with the release surface of release sheet FA, and provided as an adhesive sheet 2 for fixing a polishing pad with release sheet FA. The adhesive sheet 2 for fixing a polishing pad with release sheet FA comes in two forms: one in which the surface of adhesive layer B (the side not in contact with sheet-like substrate F) is covered with release sheet FB, as shown in Figure 1-2, and one in which no release sheet FB covers the surface of adhesive layer B, as shown in Figure 1-3. In the form of Figure 1-3, the adhesive sheet 2 for fixing a polishing pad with release sheet FA is wrapped around a cylindrical member called a core (also called a core material), as shown in Figure 1-3', and the surface of adhesive layer B is covered with the other side of release sheet FA (the side not in contact with adhesive layer A). As shown in Figure 1-4, a polishing pad PP is laminated in advance on adhesive layer B of adhesive sheet 2 for fixing a polishing pad with release sheet FA, to form polishing pad 4 with release sheet FA and adhesive layer A. Next, release sheet FA is peeled off to expose adhesive layer A, and polishing pad 3 with adhesive layer A is attached to a surface plate SP. Adhesive layer A of adhesive sheet 1 for fixing a polishing pad contacts the surface plate, and adhesive layer B contacts the polishing pad. That is, the polishing pad PP is fixed to the platen SP via the adhesive sheet 1 having a laminated structure of adhesive layer A / sheet-like substrate F / adhesive layer B.

[0026] When attaching the polishing pad PP to a surface platen via the adhesive sheet 1, in many cases, the polishing pad PP has been attached by gently bending and flexing it while slowly squeezing the surface of the polishing pad PP from the edges with a roll or squeegee, squeezing the surface of the polishing pad PP from the edges to push out the air from the edges. When attaching the adhesive layer A to the surface platen, if the adhesive sheet becomes distorted or an uneven force is applied to the adhesive sheet, a large air pocket will occur locally between the surface platen SP and the adhesive layer A. Recently, polishing pads PP have tended to become thicker, extremely hard, or extremely soft. A thicker or extremely hard polishing pad PP is too rigid and cannot be bent as before, making it impossible to fully apply a pressing roll or squeegee to the surface of the polishing pad PP. On the other hand, extremely softened PP polishing pads are prone to bending and flexing, making it difficult to maintain the bent state when squeezing the surface of the polishing pad with a roll or squeegee. In either case, the air at the adhesion interface cannot be quickly expelled or evenly distributed across the entire interface, and large air pockets tend to remain in localized areas. Furthermore, when squeezing the surface of the polishing pad PP with a roll or squeegee, pressure is applied locally to the surface of the polishing pad PP. Although the pressure is applied sequentially to the entire surface of the polishing pad, there is also a demand to avoid applying too much force to the surface of the polishing pad PP, since this is the surface that will come into contact with the object to be polished (the workpiece).

[0027] The surface of the adhesive layer A in the adhesive sheet of the present invention (the surface that will come into contact with the surface platen SP) has irregularities as determined by a Beck smoothness test. The concave portions on the surface of the adhesive layer A can be used as ventilation paths (flow paths) to push air between the surface platen SP and the adhesive layer A from the surroundings to the outside and to smooth the entire adhesion interface. As a result, it is possible to suppress or prevent the occurrence of large localized air pockets between the surface platen and the adhesive sheet that would impair the parallelism between the surface of the polishing pad (the surface that comes into contact with the polishing target) and the surface platen.

[0028] The following describes the Beck smoothness of the surface of the adhesive layer A. The Beck smoothness is defined in JIS P8119. The procedure for the Beck smoothness test will now be outlined. (1) A test piece is placed on the flat surface of an optically flat-finished glass (a ring-shaped glass member having a circular hole in the center that connects to the vacuum chamber). (2) With a pressure of 0.1 MPa applied via a pressure plate to a rubber pressure plate placed on the test specimen, the pressure inside the vacuum chamber is reduced to -50.7 kPa. (3) When the pressure reaches -50.7 kPa, stop reducing the pressure and suck in atmospheric air between the contact surface of the glass flat surface and the test piece. Measure the time it takes for the pressure inside the vacuum chamber to change from -50.7 kPa to -48.0 kPa (Condition 1), and from -50.7 kPa to -29.3 kPa (Condition 2). These values ​​can be used to evaluate the breathability of the surface of adhesive layer A. In other words, in both conditions 1 and 2, the shorter the time it takes to return to the specified pressure, the easier it is to breathe.

[0029] In the present invention, as shown in Figure 2(A), a polyethylene terephthalate (hereinafter referred to as PET) film with a thickness of 100 μm and an Rc of less than 0.5 μm on both sides is attached to adhesive layer B of the adhesive sheet, and then cut into a 50 mm square. Four sheets are stacked, and a circular hole with a radius of 5 mm (smaller than the central hole in the glass member) is drilled to prepare a measurement sample. As shown in Figure 2(B), the bottom adhesive layer A is placed on the surface of the glass member so that the hole in the measurement sample is directly above the central hole in the glass member. A rubber pressure plate is placed on top of the top PET film, and while a pressure of 0.1 MPa is applied via a pressure plate, suction is applied from below the central hole in the glass member to reduce the pressure, and the smoothness under conditions 1 and 2 is determined. Since the measurement sample consists of four stacked adhesive sheets, 1 / 4 of the measured value is the result for adhesive layer A per adhesive sheet. In other words, if the measured value is 4 seconds, the Beck smoothness of adhesive layer A is 1 second. For ease of handling during measurement, four sheets can be stacked after metal such as platinum, palladium, or gold is vapor-deposited on the surface of adhesive layer A to remove adhesive properties.

[0030] Under condition 1, it is important that the Beck smoothness of the surface of the adhesive layer A is 1 to 100 seconds, more preferably 2 to 50 seconds, particularly preferably 6 to 35 seconds, and most preferably 15 to 30 seconds. The smoothness of Condition 1 relates to the movement and state of air at the very initial stage when adhesive layer A contacts the surface plate, and is primarily related to position adjustment. In other words, if the smoothness of Condition 1 is 100 seconds or less, large localized air pockets are less likely to form when adhesive layer A contacts the surface plate, allowing adhesive layer A to adhere tightly to the surface plate. If the position of adhesive layer A in contact with the surface plate is appropriate and no position adjustment is required, if the smoothness of Condition 1 is less than 1 second, the air permeability will be too good, making the position of adhesive layer A more likely to shift. In other words, if the smoothness of Condition 1 is 1 second or more, it becomes easier to maintain the appropriate position of the polishing sheet adhering to the surface plate.

[0031] Furthermore, it is important that the Beck smoothness of the surface of the adhesive layer A is 15 to 1125 seconds under condition 2, preferably 20 to 500 seconds, more preferably 60 to 375 seconds, and most preferably 80 to 300 seconds. The smoothness of condition 2 relates to the movement and state of air for a few minutes to a dozen minutes after adhesive layer A is attached to the surface plate, and is mainly related to the air release properties of the adhesive interface. If the smoothness of condition 2 is 1125 seconds or less, even if localized air accumulation occurs between the surface plate and adhesive layer A, the air can be easily distributed across the entire adhesive interface through the recesses in the adhesive interface, or released from the periphery. If the smoothness of condition 2 is 15 seconds or more, adhesive layer A that comes into contact with the surface plate will adhere more firmly to the surface plate.

[0032] The surface of the adhesive layer B (the surface that will come into contact with the polishing pad) does not need to have any particular irregularities. When the polishing pad 3 with adhesive layer A is attached to the surface plate SP, it is attached by hand, so large localized air pockets are likely to form between the adhesive layer A and the surface plate SP. On the other hand, when the polishing pad PP is attached to the adhesive layer B of the adhesive sheet 2 for fixing a polishing pad with the release sheet FA, it is attached mechanically, not by hand, so unlike when the polishing pad 3 is attached to the surface plate SP, large localized air pockets are unlikely to form in the first place.

[0033] The shape of the irregularities (cross section) on the surface of the adhesive layer A will be described. From the viewpoint of improving alignment, it is preferable that the top of the convex portion be gently rounded as shown in Figure 3-1 rather than flat as shown in Figure 3-2. Also, from the viewpoint of improving air release, Figure 3-1, in which the recess of adhesive layer A is wider, is preferable to Figure 3-2. In Figure 3-3, the recess of adhesive layer A is wider than in Figure 3-2, so some improvement in air release can be expected. However, there is a risk that the polishing accuracy will decrease due to the wider recess of adhesive layer A.

[0034] Therefore, to improve alignment and air release without reducing polishing accuracy, the average height Rc of the roughness curve elements on the surface of the adhesive layer A (hereinafter referred to as "average height Rc") is preferably 10 to 40 μm, more preferably 15 to 35 μm, and even more preferably 20 to 30 μm. An average height Rc of 10 μm or more results in relatively deep recesses, improving breathability under both conditions 1 and 2 in the Beck smoothness test, improving alignment and air release, and significantly affecting air release, making it easier to peel the polishing pad and adhesive sheet from the surface plate after polishing is complete. An average height Rc of 40 μm or less improves polishing accuracy on the surface plate.

[0035] The shape of the irregularities on the surface of the adhesive layer A of the present invention can be more specifically understood from two parameters: the difference in cutting level of the contour curve: Rδc and kurtosis: Rku, in terms of the roundness and inclination of the convex parts, and the spacing between the irregularities. Rδc is preferably 5 to 25 μm, more preferably 10 to 20 μm, and even more preferably 12.5 to 19.0 μm. Rδc is the difference in height level that corresponds to any two load length ratios from a load curve (a curve in which the ratio of the solid body length to the measured length is plotted in order of height), and in the present invention, the two load length ratios are defined as 0% and 50%. By setting Rδc to 5 μm or more, air pockets are less likely to form in the very early stages of application, and the tops of the convex portions of adhesive layer A come into loose (light) contact with the surface plate. In other words, the adhesive layer does not adhere very firmly to the surface plate, so when peeling adhesive layer A from the surface plate once it has come into contact with it, it can be peeled off with little resistance, making it easier to adjust the position. Incidentally, because adhesive layer A is adhesive, it is thought that it will deform to some extent when it is attached to a surface plate. In other words, it is thought that microscopically, the convex parts on the surface of adhesive layer A will be crushed, albeit slightly, during attachment, and the concave parts will become somewhat shallower in comparison. By setting Rδc to 25 μm or less, adhesive layer A will be less likely to be crushed when adhesive layer A is firmly attached to a surface plate, the depth of the concave parts will be maintained, and air release will be improved.

[0036] Furthermore, the kurtosis (Rku) of the surface of the adhesive layer A is preferably less than 3. An Rku of less than 3 indicates a rounded convex shape. By contacting the rounded tops of the convex portions with the surface plate during application, alignment can be performed with a feeling of adhesion. In particular, an Rku in the range of 1.5 or more and less than 3 is particularly preferable because it improves workability during alignment and provides strong adhesion when firmly pressed against the surface to prevent problems such as peeling during polishing.

[0037] Rc, Rδc, and Rku will be explained using a schematic diagram. Figures 3-1, 3-4, and 3-5 show cases where Rc is about the same. If Figure 3-1 shows a case where Rδc is 5 to 25 μm and Rku is less than 3, in the case of Figure 3-4, where the slope of the convex part is steeper than in Figure 3-1, Rδc is larger than in Figure 3-1, and Rku is less than 3. Similarly, in Figure 3-5, where the slope of the convex part is steeper than in Figure 3-1, Rδc is larger than in Figure 3-1, and because the top of the convex part is pointed, Rku is larger than 3. Also, Figures 3-6 and 3-7 imagine a case where Rc is about the same as in Figure 3-1, but because the spacing between the protrusions and recesses is wider than in Figure 3-1, Rδc is smaller than in Figure 3-1, and in Figure 3-6 Rku is 3 smaller, while in Figure 3-7 Rku is greater than 3.

[0038] Rc, Rδc, and Rku are values ​​measured based on JIS B 0601 (2013) and can be measured using a digital microscope (Keyence VHX-7000). Specifically, at 400x magnification, five images are taken continuously in each direction across a field of view approximately 460 μm long and 640 μm wide (25 images in total), and the entire observation field is defined as an area of ​​approximately 2300 μm long and 3200 μm wide. The measurement field is defined as an area of ​​approximately 1840 μm long and 2560 μm wide in the center of the entire observation field. Rc, Rδc, and Rku are measured along two diagonals of the measurement field, and the average values ​​are calculated. The same applies to the measurement of Rc etc. of the release sheet FA described later.

[0039] The unevenness in the present invention is different from the so-called "matt" unevenness intended to achieve an optically matte finish, and the unevenness on the surface of the adhesive layer A in the present invention is large and rough. An image of the unevenness on the surface of the adhesive layer A in the present invention is shown in Figure 4-1, and an image of the so-called "matt" unevenness is shown in Figure 4-2. Rc, Rδc, and Rku in the above ranges represent an ideal shape, with a larger difference in height between the concaves and convexes and a wider spacing between the concaves and convexes than the so-called "matt" that is generally known for its optically matte finish, allowing for initial positioning adjustment, air release during application, and fixing the polishing pad to the surface plate in a parallel and smooth manner.

[0040] The unevenness (plan view) on the surface of the adhesive layer A will be described. The unevenness (in plan view) on the surface of the adhesive layer A in the present invention may be a regular pattern or design such as a lattice pattern or polka dot pattern, but is preferably irregular and amorphous as shown below. An example of an image of the surface of adhesive layer A observed with a laser microscope is shown in Figure 5. The black parts in the upper images of Figures 5-1 and 5-2 are convex parts, which are irregular and amorphous in plan view. Examples of irregular and amorphous patterns and designs in the present invention include patterns and designs such as those shown in Figures 6(1) to (4). Figure 6(1) is sometimes called sand grain, leather grain, rock grain, pebble grain, or matte. Figure 6(2) is a type of uneven pattern and design called mottling in the field of ink and paint. Figure 6(3) is also called mottling, but is a pattern and design seen on decorative stickers for plastic models, etc. Figure 6(4) is sometimes called a Dalmatian pattern. In the patterns and designs shown in Figures 6(1) to (4), there is no regularity in the position of either the convex parts (black parts) or the concave parts (white parts), and no regularity can be recognized in the shape either.

[0041] As long as the Beck smoothness of the surface of adhesive layer A is within the above ranges under conditions 1 and 2, whether the shape of the unevenness in plan view is irregular and amorphous or regular and regular makes no difference in terms of positioning when affixing to a surface plate or air release. However, an irregular and irregular pattern or design in plan view makes it easier to reduce bias in the force applied during affixing and makes it easier to affix uniformly. Furthermore, even if unevenness occurs on adhesive layer A to a degree that does not affect performance, an irregular and irregular pattern or design in plan view is preferable because it is less noticeable.

[0042] A method for obtaining an adhesive layer A having a Beck smoothness within a predetermined range is to use a release sheet FA having irregularities on the surface with an average height Rc of 12 to 42 μm. That is, a release sheet FA' having a release layer is prepared, and then, as shown in Figure 7-1, the release sheet FA' is passed at high temperature between a metal roll R1 and a rubber roll R2, which have been processed to the desired surface shape, thereby inverting and transferring the surface shape of the metal roll R1 to produce a release sheet FA having irregularities with an average height Rc of 12 to 42 μm. Note that when the surface shape of the release sheet FA is inverted and transferred by the rotation of the metal roll R1, the surface shape will have a certain periodicity, but this periodicity is different from the regularity in the plan view described above.

[0043] and, (1) Adhesive a is applied onto the release layer of the release sheet FA and dried as necessary to form adhesive layer A. (2) A sheet-like substrate is placed on the surface of the adhesive layer A that is not in contact with the release sheet FA. (3) The adhesive b is applied to the release-treated surface of the release sheet FB and dried as necessary to form an adhesive layer B. (4) The surface of the sheet-like substrate that is not in contact with the adhesive layer A is superimposed on the surface of the adhesive layer B that is not in contact with the release sheet FB. As a result, an adhesive sheet for fixing a polishing pad with a release film having a laminated structure of [release sheet FA / adhesive layer A / sheet-like substrate F / adhesive layer B / release sheet FB] as shown in Figure 7-2 can be produced.

[0044] or, (5) An adhesive agent a is applied to one surface of the sheet-like substrate and dried as necessary to form an adhesive layer A. (6) The surface of the adhesive layer A that is not in contact with the sheet-like substrate is overlaid with the surface of a release sheet FA that has been subjected to a release treatment and has an average height Rc of the irregularities on the surface of 12 to 42 μm. (7) The adhesive b is applied to the release-treated surface of the release sheet FB and dried as necessary to form an adhesive layer B. (8) The surface of the sheet-like substrate that is not in contact with the adhesive layer A is superimposed on the surface of the adhesive layer B that is not in contact with the release sheet FB. Using this method, it is possible to produce an adhesive sheet for fixing a polishing pad with a release film having a laminated structure of [release sheet FA / adhesive layer A / sheet-like substrate F / adhesive layer B / release sheet FB] as shown in Figure 7-2.

[0045] or, (9) The adhesive b is applied to the release-treated surface of the release sheet FB and dried as necessary to form an adhesive layer B. (10) A sheet-like substrate is placed on the surface of the adhesive layer B that is not in contact with the release sheet FB. (11) An adhesive agent a is applied to the release-treated surface of a release sheet FA having an average height Rc of the irregularities on the release-treated surface of 12 to 42 μm, and dried as necessary to form an adhesive layer A. (12) The surface of the adhesive layer A that is not in contact with the release sheet FA is superimposed on the surface of the sheet-like substrate that is not in contact with the adhesive layer B. Using this method, it is possible to produce an adhesive sheet for fixing a polishing pad with a release sheet having a laminated structure of [release sheet FA / adhesive layer A / sheet-like substrate F / adhesive layer B / release sheet FB] as shown in Figure 7-2. In either case, it is preferable that the surface of adhesive layer B (the surface that will come into contact with the polishing pad) is free of irregularities, and therefore the release surface of release sheet FB onto which adhesive b is applied is preferably smooth.

[0046] The adhesive can be applied by a known method such as a roll coater method, a comma coater method, a lip coater method, a die coater method, a reverse coater method, a silk screen method, a gravure coater method, etc. After application, the adhesive can be dried using a hot air oven, an infrared heater, or the like.

[0047] By peeling off the release sheet FB from an adhesive sheet 2 for fixing a polishing pad with a release sheet having a laminated structure of [release sheet FA / adhesive layer A / sheet-like substrate F / adhesive layer B / release sheet FB] obtained by various methods and attaching a polishing pad PP to the exposed adhesive layer B as shown in Figure 7-3, a polishing pad 4 with a release sheet and adhesive layer having a laminated structure of [release sheet FA / adhesive layer A / sheet-like substrate F / adhesive layer B / polishing pad PP] can be obtained. Next, by peeling off the release sheet FA that covered the adhesive layer A from the resulting polishing pad 4 with the release sheet and adhesive layer, the unevenness of the release sheet FA is inversely transferred to the adhesive layer A, thereby obtaining an adhesive layer A with the desired Beck smoothness. Then, as shown in Figure 7-4, by attaching the exposed adhesive layer A to a surface plate SP, the polishing pad PP can be fixed to the surface plate SP via the adhesive sheet 1.

[0048] In addition to the transfer method described above, an adhesive layer A having the desired roughness can also be formed by ejecting adhesive onto the surface of an adhesive layer having a smooth surface using an inkjet, creating a pattern with the desired surface shape, and then drying and hardening the same. Alternatively, the desired roughness can be obtained by pressing a metal plate having the desired roughness against a smooth adhesive layer at a high temperature. Alternatively, the surface of the smooth adhesive layer can be processed by laser to burn off a part of the adhesive layer. Among the above, the method of forming an adhesive layer on a release film having the desired unevenness and transferring the unevenness of the release film to the adhesive layer to obtain adhesive layer A is preferred because it provides stable production quality and fast production speed.

[0049] <Adhesive layer> In the pressure-sensitive adhesive sheet for fixing a polishing pad of the present invention, the pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B are located on the outermost surfaces of the pressure-sensitive adhesive sheet, respectively. The sheet-like substrate may be a single layer or may be a laminate of various members, with no particular limitation on the number of layers. The thickness of the adhesive layer A of the adhesive sheet for fixing a polishing pad is preferably 15 to 100 μm, more preferably 30 to 70 μm. By making the thickness of the adhesive layer A 15 μm or more, adhesive strength is easily exerted, and by making it 100 μm or less, the desired uneven shape of the present invention is easily formed. A thickness within this more preferred range provides excellent adhesiveness and prevents the adhesive layer from shifting in the shear direction when the adhesive sheet becomes hot during polishing. The thickness is the average value measured at five random points using a Mitutoyo Litematic VL-50B thickness gauge with a 7.5 mm diameter probe at a pressure of 0.01 N. The thickness of adhesive layer B is not particularly limited as long as it can fix various polishing pads, but by making the combined thickness of adhesive layer A excluding the thickness of the base layer 200 μm or less, the proportion of the adhesive layer, which is a low-elastic material, in the entire adhesive sheet is reduced, thereby improving polishing accuracy.

[0050] The adhesive layers A and B of the adhesive sheet of the present invention can be made of acrylic adhesives, elastomer adhesives, urethane adhesives, silicone adhesives, etc., and two or more types may be used in combination. Acrylic adhesives are preferred from the viewpoints of less gel formation, less likelihood of local differences in elastic modulus, and ease of control of adhesive strength. Elastomer-based and urethane-based adhesives often use metal catalysts during synthesis, and silicone-based adhesives often use metal catalysts during curing. However, acrylic adhesives contain a low amount of metal catalyst, making them less likely to affect CMP processing and more chemically resistant, making them preferable. Furthermore, for adhesive layer B, it is preferable to select an acrylic adhesive with a wide variety of monomer species in order to accommodate the wide variety of polishing pad materials.

[0051] <Acrylic adhesive> The acrylic adhesive contains an acrylic copolymer and a curing agent. It may also contain a tackifying resin. The acrylic copolymer preferably has a carboxyl group or a hydroxyl group, and more preferably is a (meth)acrylate resin having a hydroxyl group.

[0052] <(Meth)acrylate resin> The (meth)acrylate resin is obtained by copolymerizing a monomer having a hydroxyl group with another monomer not having a hydroxyl group, i.e., the (meth)acrylate resin is a copolymer consisting of a unit derived from the monomer having a hydroxyl group and a unit derived from the other monomer.

[0053] Examples of the monomer having a hydroxyl group include hydroxyalkyl (meth)acrylate and a compound in which ε-caprolactone is added to the hydroxyalkyl (meth)acrylate, with hydroxyalkyl (meth)acrylate being preferred.

[0054] Specific examples of hydroxyalkyl (meth)acrylates include hydroxyalkyl (meth)acrylates in which the alkyl group has 1 to 4 carbon atoms, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate. Specific examples of compounds in which ε-caprolactone is added to hydroxyalkyl (meth)acrylates include ε-caprolactone adducts of hydroxyalkyl (meth)acrylates having 1 to 4 carbon atoms, such as an ε-caprolactone 1-mol adduct of 2-hydroxyethyl (meth)acrylate, an ε-caprolactone 2-mol adduct of 2-hydroxyethyl (meth)acrylate, and an ε-caprolactone 3-mol adduct of 2-hydroxyethyl (meth)acrylate, but the present invention is not limited to these examples. These hydroxyl group-containing monomers may be used alone or in combination. 2-Hydroxyethyl (meth)acrylate is particularly preferred from the viewpoint of improving chemical resistance due to the relatively short intermolecular distance when crosslinked with an isocyanate curing agent.

[0055] Examples of other monomers not having a hydroxyl group include the following various monomers: Examples of alkyl (meth)acrylates include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, isoamyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isononyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, and tert-butylhexyl (meth)acrylate, as well as 2-acetoacetoxyethyl (meth)acrylate and phenoxyethyl (meth)acrylate.

[0056] The weight-average molecular weight (Mw) of the acrylic copolymer is preferably 200,000 to 1,500,000, and more preferably 500,000 to 1,000,000. When the weight-average molecular weight (Mw) is 200,000 or more, the adhesive can easily obtain cohesive strength capable of withstanding strong shearing force, and when it is 1,500,000 or less, the adhesive has excellent heat resistance and adhesion to the abrasive is less likely to decrease, and when it is in the more preferred range, performance is improved.

[0057] Examples of methods for polymerizing the monomer include solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization, but the present invention is not limited to these polymerization methods. Among these polymerization methods, solution polymerization is preferred because the resulting reaction mixture can be used as is.

[0058] <Elastomer-based adhesive> The elastomeric pressure-sensitive adhesive contains an elastomer and a tackifying resin. The elastomer preferably contains a styrene-isoprene block copolymer.

[0059] Styrene-isoprene block copolymers exist in either a linear or radial structure. The linear structure provides excellent adhesion to a variety of substrates due to its high flexibility, and exhibits superior adhesive performance and heat resistance. Therefore, a linear structure consisting of a styrene-isoprene-styrene block triblock (SIS) or a styrene-isoprene diblock (SI) is preferred. A linear styrene-isoprene block copolymer is a linear copolymer in which a styrene block and an isoprene block are bonded.

[0060] The styrene-isoprene block copolymer preferably has a styrene content of 20 to 40% by weight based on 100% by weight. The diblock content is preferably 15 to 70% by weight. When the styrene content and the diblock content are within the above ranges, the adhesive has excellent cohesive strength, and improves holding power and chemical resistance after exposure to a high-humidity environment.

[0061] Examples of styrene-isoprene block copolymers include, but are not limited to, Kraton D1119 (Kraton Corporation, styrene content 22 wt%, diblock content 66 wt%), Kraton D1126 (Kraton Corporation, styrene content 21 wt%, diblock content 30 wt%), and Kraton D1117 (Kraton Corporation, styrene content 17 wt%, diblock content 33 wt%). Two or more types may be used in combination as needed.

[0062] Natural rubber may also be contained within a range that does not impair the required performance. The natural rubber is not particularly limited, but it is preferably masticated with a mastication roll to have a Mooney viscosity of, for example, 10 to 100. The other elastomers and natural rubbers are not limited to these, and one or a combination of two or more types may be used.

[0063] <Silicone-based adhesive> Silicone adhesives can be made from known silicone resins. Specifically, organopolysiloxanes with silanol groups at both ends of the molecular chain are combined with RSiO 0.5 Examples include those obtained by partial dehydration condensation of organopolysiloxanes having triorganosiloxane units represented by the formula (where R represents a substituted or unsubstituted monovalent hydrocarbon group) and SiO2 units. These are available as silicone-based adhesives KR-101-10, KR-120, KR-130, and X-40-3068 (all manufactured by Shin-Etsu Chemical Co., Ltd.). Silicone-based adhesives are generally cured using peroxides such as benzoyl peroxide, or using a reaction between a platinum catalyst and an organopolysiloxane having a Si-H bond. Either method can be used, or they can be used in combination.

[0064] <Tackifying resin> Examples of tackifying resins include rosin-based resins such as rosin ester, polymerized rosin, hydrogenated rosin, disproportionated rosin, maleic acid-modified rosin, fumaric acid-modified rosin, and rosin phenolic resin; terpene-based resins such as α-pinene resin, β-pinene resin, dipentene resin, aromatic-modified terpene resin, hydrogenated terpene resin, terpene phenolic resin, acid-modified terpene resin, and styrenated terpene resin; alkylphenol resin, coumarone resin, styrene resin, petroleum-based resin, or copolymers thereof, with terpene phenolic resin being particularly preferred. The above tackifying resins can be used alone or in combination of two or more. <Curing agent>

[0065] A curing agent can be added to the adhesive as needed. The peel strength required when peeling from the polishing machine platen varies from high to low, so a curing agent can be added to control the adhesive strength. As the curing agent, an isocyanate-based curing agent, an aziridine-based curing agent, a metal chelate-based curing agent, an epoxy-based curing agent, or the like can be used as needed, as long as the desired performance is not impaired. In particular, an isocyanate-based curing agent is preferred as the curing agent added to an acrylic adhesive from the viewpoints of cohesive strength and heat resistance. These curing agents may be used alone or in combination of two or more.

[0066] <Other additives> The various adhesives for forming the adhesive layer in the adhesive sheet of the present invention may contain various additives as needed, such as known antioxidants such as antioxidants, fillers, pigments, dyes, diluents, plasticizers, polymerization inhibitors, UV absorbers, UV stabilizers, coupling agents, etc., and two or more of these may be used. The amount of additive added is not particularly limited, as long as it is an amount that provides the required physical properties.

[0067] <Release Sheet FA>, <Release Sheet FB> The release sheets FA and FB have a release layer formed by applying a release agent to a sheet-like substrate such as paper, plastic film, synthetic paper, etc. In CMP processing, a release film with a highly clean plastic film as the sheet-like substrate is preferred. As a plastic film for release sheet FA, a polyethylene terephthalate film is preferred because it is easy to process the texture with a metal roll and is inexpensive. For the texture processing of the release film with the exemplified metal roll, a thickness of 25 to 100 μm is preferred because it makes it easy to transfer the desired shape formed on the metal surface, and a thickness of 45 to 80 μm is even more preferred because it makes processing easier. The average height Rc of the release sheet FA is preferably 12 to 42 μm, more preferably 17 to 37 μm, and even more preferably 22 to 32 μm, in order to inversely transfer the irregularities of the release sheet FA onto the surface of the adhesive layer A. When the average height Rc is within the preferred range, the irregular surface can be inversely transferred onto the adhesive layer A with high accuracy.

[0068] The plastic film for the release sheet FB is preferably an inexpensive and highly smooth polyethylene terephthalate film. There is no particular restriction on the thickness of the release sheet FB, but it is preferably 10 to 200 μm, which gives the film stiffness and makes it easy to peel. Examples of the release agent include silicone resins, alkyd resins, melamine resins, fluorine resins, and acrylic resins, with silicone resins being preferred.

[0069] <Sheet-shaped substrate> The sheet-like substrate of the present invention is preferably a nonwoven fabric or a plastic film. Examples of the plastic film include films made of polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, PPS (polyphenylene sulfide), nylon, triacetyl cellulose, cycloolefins, polyimides, polyamides, etc. In particular, polyethylene terephthalate films are preferred because of their low production costs, chemical resistance, and smoothness.

[0070] The thickness of the sheet-like substrate is not particularly limited, but is preferably 5 to 200 μm, more preferably 25 to 75 μm, and particularly preferably 50 to 75 μm. When the thickness is within the preferred range, the unevenness of adhesive layer A does not affect adhesive layer B or the polishing pad, and appropriate stiffness is imparted, improving workability during application. When the thickness is within the particularly preferred range, workability is further improved.

[0071] The sheet-like substrate in the present invention may be subjected to an adhesion-facilitating treatment in order to improve the adhesion between the adhesive layer A and the adhesive layer B. The adhesion-facilitating treatment can be performed by a known method such as a dry method involving corona discharge or a wet method involving coating with an anchor coating agent. When an acrylic adhesive is used to form the adhesive layer, it is preferable to use one that has been subjected to an easy-adhesion treatment in terms of improving adhesion. On the other hand, when an elastomeric adhesive is used, if it has been subjected to an easy-adhesion treatment by corona discharge, the adhesive layer is more likely to peel off from the sheet-like substrate, so it is preferable to apply the elastomeric adhesive to the surface that has not been subjected to the easy-adhesion treatment.

[0072] The thickness of the adhesive sheet for fixing a polishing pad, which is composed of adhesive layer A, sheet-like substrate, and adhesive layer B, is preferably 80 to 300 μm, and more preferably 100 to 200 μm. A thickness of 80 μm or more allows for uniform processing without bias in the lamination process when integrating with the polishing pad, and a thickness of 300 μm or less allows for the adhesive sheet to be formed into a roll shape during production, increasing productivity. A thickness within this more preferred range allows the force of the platen to be appropriately transmitted to the polishing pad during polishing, improving polishing precision.

[0073] <Usage form> An example of the use of the pressure-sensitive adhesive sheet for fixing a polishing pad of the present invention will be described. As shown in Figures 1-2 and 7-2, the adhesive sheet for fixing a polishing pad can be provided as an adhesive sheet for fixing a polishing pad with a release sheet FA, in which each side of the sheet is covered with a release sheet FA and FB, respectively, or as shown in Figure 1-3, the adhesive sheet for fixing a polishing pad can be provided in a state in which only the adhesive layer A side of the adhesive sheet for fixing a polishing pad is covered with a release sheet FA. In the case of the form shown in Figure 1-3', the adhesive sheet for fixing a polishing pad with a release sheet FA 2 can be wrapped around a cylindrical member called a core (also called a core material), and the surface of adhesive layer B can be covered with the other side of the release sheet FA (the side not in contact with adhesive layer A), and the adhesive sheet for fixing a polishing pad with a release sheet FA in roll form can be provided.

[0074] As shown in Figures 1-4 and 7-3, a polishing pad is laminated on the surface of adhesive layer B of the adhesive sheet for fixing a polishing pad with release sheet FA, and a polishing pad 4 with release sheet FA and adhesive layer A is formed. Next, as shown in Figures 1-5 and 7-4, the release sheet FA is peeled off to expose the adhesive layer A, and the polishing pad 3 with the adhesive layer A is attached to a surface plate SP. The adhesive layer A of the adhesive sheet 1 for fixing a polishing pad contacts the surface plate, and the adhesive layer B contacts the polishing pad.

[0075] A polishing pad, also known as a polishing cloth, polishing pad, or polishing pad, is a component that comes into contact with the surface of the object to be polished and polishes it. Polishing pads are available in single-layer types made from a single component, and multi-layer types made from multiple laminated components. Materials for the top surface of polishing pads include urethane, nonwoven fabric, and suede. In the case of multi-layer types, urethane foam, polyethylene foam, or polypropylene foam is used as a cushioning material in the inner layer. [Example]

[0076] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. In the examples, "parts" means "parts by weight" and "%" means "% by weight".

[0077] [Molecular weight] In the following examples, the molecular weights are polystyrene-equivalent weight-average molecular weights measured by GPC (gel permeation chromatography). The measurement was performed using a GPC-8020 (Tosoh Corporation) measuring instrument, tetrahydrofuran as the eluent, and three TSKgel SuperHM-M (Tosoh Corporation) columns at a column temperature of 40°C, a flow rate of 0.6 mL / min, a sample concentration of 0.3%, and an injection volume of 10 μL.

[0078] [Non-volatile content] The non-volatile content is calculated by dividing the mass of a sample before heating by the mass of the sample after heating when 1 g of the sample is heated at 170°C for 10 minutes. However, for commercially available products, the value calculated based on the method specified by the manufacturer may be used.

[0079] (adhesive) <Preparation of acrylic adhesive (P-1) solution> 500 g of ethyl acetate was heated in a water bath while introducing nitrogen gas into a four-neck flask equipped with a stirrer, reflux condenser, nitrogen inlet, and thermometer. Subsequently, a mixture of 360 g of BA (n-butyl acrylate), 120 g of 2-EHA (2-ethylhexyl acrylate), 10 g of AA (acrylic acid), 5 g of HEA (hydroxyethyl acrylate), and 0.5 g of AIBN (azobisisobutyronitrile) as an initiator was added dropwise to the ethyl acetate and allowed to react for 8 hours while maintaining reflux. After the reaction, 110 g of ethyl acetate was added to obtain a solution of acrylate resin p-1 (45% nonvolatile content) with a weight-average molecular weight (Mw) of 510,000. Furthermore, 100 parts of the acrylate resin p-1 solution and 3 parts of an isocyanate-based curing agent (Mitsubishi Chemical Corporation (Mytec GP105A): tolylene diisocyanate, trimethylolpropane adduct) were mixed and stirred, and methyl ethyl ketone was added as a solvent to prepare a solution of acrylic adhesive (P-1) (non-volatile content 45%).

[0080] <Preparation of acrylic adhesive (P-2) solution> 500 g of ethyl acetate was heated in a water bath while introducing nitrogen gas into a four-neck flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, and thermometer. Subsequently, a mixture of 120 g of BA (n-butyl acrylate), 360 g of 2-EHA (2-ethylhexyl acrylate), 20 g of AA (acrylic acid), and 0.3 g of AIBN (azobisisobutyronitrile) as an initiator was added dropwise to the ethyl acetate and reacted for 8 hours while maintaining reflux. After the reaction, 110 g of ethyl acetate was added to obtain a solution of (meth)acrylate resin p-2 (45% nonvolatile content) with a weight-average molecular weight (Mw) of 800,000. Furthermore, 100 parts of the solution of acrylate resin p-2 and 3 parts of an isocyanate-based curing agent (Mitsubishi Chemical Corporation (Mytec GP105A): tolylene diisocyanate, trimethylolpropane adduct) were mixed and stirred, and methyl ethyl ketone was added as a solvent to prepare a solution of acrylic adhesive (P-2) (non-volatile content 45%).

[0081] <Production of acrylic adhesive (P-3) solution> A solution of 100 parts of acrylate resin p-2 (45% non-volatile content), 10 parts of O-130P (epoxidized soybean oil, manufactured by Adeka Corporation), and 3 parts of an isocyanate-based curing agent (Mytec GP105A, manufactured by Mitsubishi Chemical Corporation: tolylene diisocyanate, trimethylolpropane adduct) was mixed with stirring, and methyl ethyl ketone was added as a solvent to prepare a solution of acrylic adhesive (P-3) (45% non-volatile content).

[0082] <Preparation of elastomer adhesive (P-4) solution> A four-neck flask equipped with a stirrer, thermometer, reflux condenser, dropping device, and nitrogen inlet tube was charged with 100 parts of Quintac 3270 (manufactured by Zeon Corporation, styrene content 24 wt%, diblock content 67 wt%) as an elastomer, and appropriate amounts of methyl ethyl ketone and toluene as a solvent under a nitrogen atmosphere. The flask was then gradually heated, and heating was continued for 3 hours at an internal temperature of approximately 50°C. After heating, the mixture was cooled and cooled to an internal temperature of approximately 40°C or below. 39 parts of YS Polystar T130 (Yasuhara Chemical Co., Ltd., softening point 130±5°C, hydroxyl value 60 mgKOH / g) were added as a tackifying resin, 10 parts of O-130P (Adeka Corporation, epoxidized soybean oil), and 2 parts of Irganox 1010 (BASF Japan Ltd., antioxidant) were added as an antioxidant. The mixture was diluted with methyl ethyl ketone and toluene, and stirring was continued until the tackifying resin was dissolved. 1 part of an isocyanate-based curing agent (Mitsubishi Chemical Corporation (Mytec GP105A): tolylene diisocyanate, trimethylolpropane adduct) was added to obtain a solution of elastomer adhesive (P-4) (non-volatile content 40%).

[0083] Peel-off sheet <fa-1>Manufacturing A PET release film "RF2PETCS001-50" (thickness: 50 μm, one side silicone release treatment, Rc: 0.2 μm) manufactured by Aim Co., Ltd., measuring approximately 30 cm x 30 cm, was passed between a metal roll and a rubber roll with a PG7 pattern (grained pattern) owned by Godo Resin Industries Co., Ltd. at a temperature of 220°C, a pressure of 5 MPa, and a speed of 3 m / min to obtain a release sheet FA-1 with the grained pattern transferred onto it. Rc measured by the above method using a digital microscope (Keyence VHX-7000) was 6.1 μm. The thickness of the PET release film was measured at five arbitrary points using a thickness gauge, Litematic VL-50B (manufactured by Mitutoyo Corporation), with a probe of Φ7.5 mm, and a pressure of 0.01 N, and was the average value.

[0084] Peel-off sheet <fa-2> ~ <fa-6>Manufacturing Sand-grained release sheets FA-2 to FA-7 were obtained under the same processing conditions as for release sheet FA-1, except that metal rolls with PG16, PG12, PG14, PG18, and PG68 patterns owned by Godo Resin Industries Co., Ltd. were used instead of the PG7 patterned metal roll owned by the same company.

[0085] Peel-off sheet <fa-7> ~ <fa-10>Manufacturing After obtaining release sheets FA-3, FA-4, FA-5, and FA-6, each release sheet was passed between a smooth-surfaced metal roll and a rubber roll at a temperature of 110°C, a pressure of 3.0 MPa, and a speed of 0.5 m / min to obtain release sheets FA-7, FA-8, FA-9, and FA-10.

[0086] Peel-off sheet <fa-11>Manufacturing Instead of the metal roll with the PG7 pattern owned by Godo Resin Industries, a metal roll with a lattice pattern owned by the same company (line width 200 μm, line height 26 μm, 1400 μm x 1400 μm lattice pattern) was used, and the processing conditions were the same as for release sheet FA-1, i.e., RF2PETCS001-50 was passed between the metal roll and the rubber roll at a temperature of 220°C, a pressure of 5 MPa, and a speed of 3 min / m, to obtain a lattice-patterned release sheet FA-11.

[0087] Peel-off sheet <fa-12>Manufacturing A sand-grained release sheet FA-12 was obtained under the same processing conditions as for release sheet FA-1, except that a metal roll with a PG27 pattern owned by Godo Resin Industries Co., Ltd. was used instead of a metal roll with a PG7 pattern owned by the same company.

[0088] Peel-off sheet <fa-13>Manufacturing Instead of using a metal roll with a PG7 pattern owned by Godo Resin Industries, RF2PETCS001-50 was passed between a metal roll with a grid pattern owned by the company (line width 200 μm, line height 26 μm, 1400 μm x 1400 μm grid pattern) and a rubber roll under conditions of temperature: 200°C, pressure: 1.0 MPa, and speed: 15 m / min, to obtain release sheet FA-13 with the sand-grain pattern transferred onto it.

[0089] The detailed Rc of each release sheet FA-1 to FA-12 is as follows: FA-1 PG7 (grained pattern) transfer. Rc: 6.1 μm FA-2 PG16 (grained pattern) transfer. Rc: 8.3 μm FA-3 PG12 (grained pattern) transfer. Rc: 11.5 μm FA-4 PG14 (grained pattern) transfer. Rc: 21.2 μm FA-5 PG18 (grained pattern) transfer. Rc: 33.1 μm FA-6 PG68 (grained pattern) transfer. Rc: 38.7 μm FA-7: Processed with release sheet FA-3. Rc: 9.7 μm FA-8: Processed with release sheet FA-4. Rc: 16.3 μm FA-9: Processed with release sheet FA-5. Rc: 28.7 μm FA-10: Processed with release sheet FA-6. Rc: 35.8 μm FA-11 lattice pattern transfer. Rc:25.4μm FA-12 PG27 (grained pattern) transfer. Rc: 48.0 μm FA-13 lattice pattern transfer. Rc: 4.2μm

[0090] <Release Sheet FB> FB-1 RF2PETCS001-50, manufactured by Aim Co., Ltd., PET release film (thickness: 50 μm, one side silicone release treatment, Rc: 0.2 μm)

[0091] <Other release sheets> FH-21 Matte grade polyester film (Unitika, Emblet "PTH-38") is coated with BYK's silicone treatment agent "BYK300" at 0.1g / m using a coil bar. 2 Film coated and used as a release surface. Rc: 1.5 μm

[0092] <Sheet-shaped substrate F> Sheet substrate F-1: PET25 PET film manufactured by Unitika Ltd. (thickness: 25 μm) Sheet substrate F-2: PET75 PET film manufactured by Unitika Ltd. (thickness: 75 μm) Sheet substrate F-3: PET5 PET film manufactured by Unitika Ltd. (thickness: 5 μm)

[0093] Example 1: Production of an adhesive sheet for fixing a polishing pad and an adhesive sheet for fixing a polishing pad with a release sheet A solution of adhesive P-1 was applied to the release surface of release sheet FA-1 using a doctor blade so that the thickness would be 50 μm after drying, and the coating was dried in an oven at 80°C to form adhesive layer A-1. Sheet-like substrate F-1 was then bonded to the surface of adhesive layer A-1 using a hand roller. Separately, a solution of adhesive P-2 was applied to the release surface of release sheet FB-1 using a doctor blade so that the thickness would be 50 μm after drying, and the coating was dried in an oven at 80° C. to form adhesive layer B-1. Next, the opposite side of adhesive layer B-1 from the release sheet FB-1 was attached to the opposite side of adhesive layer A-1 via sheet-like substrate F-1 using a hand roller to obtain an adhesive sheet for fixing a polishing pad with a release sheet, in which release sheet FA-1 was attached to adhesive layer A-1 and release sheet FB-1 was attached to adhesive layer B-1, of a laminated structure of [adhesive layer A-1 / sheet-like substrate F-1 / adhesive layer B-1]. The properties of the resulting adhesive sheet (Beck smoothness, average roughness Rc, cut level difference Rδc of the profile curve, and kurtosis Rku of the surface of the exposed adhesive layer A-1) were determined according to the methods described below. Furthermore, the performance of the resulting pressure-sensitive adhesive sheets (ease of application, air release, adhesive strength, alkali resistance, holding power, and polishing accuracy) was evaluated according to the methods described below.

[0094] <Examples 2 to 11> An adhesive sheet for fixing a polishing pad with a release sheet was obtained in the same manner as in Example 1, except that instead of release sheet FA-1, the release films to which the solution of adhesive P-1 was applied were changed to FA-2 to FA-11 as shown in Table 1.

[0095] <Examples 12 to 17> An adhesive sheet for fixing a polishing pad with a release sheet was obtained in the same manner as in Example 1, except that release sheet FA-5 was used instead of release sheet FA-1, and a solution of adhesive P-2 or P-4 was used instead of the solution of adhesive P-1, the thickness of adhesive layer A was changed, the sheet-like substrate was changed, or the thickness of adhesive layer B was changed, as shown in Table 1.

[0096] <Comparative Examples 1 to 4> Adhesive sheets for fixing polishing pads with release sheets were obtained in the same manner as in Example 1, except that instead of release sheet FA-1, the release films onto which the solution of adhesive P-1 was applied were FB-1, FH-21, FA-12, and FA-13, as shown in Table 1.

[0097] [Properties of adhesive sheet] <Beck smoothness> The release sheet FB covering the adhesive layer B was peeled off from the adhesive sheet for fixing a polishing pad with a release sheet produced in the examples and comparative examples, and the exposed adhesive layer B was bonded to a 100 μm PET film (Rc: 0.2 μm) and cut into a 50 mm square size. Next, the release sheet FA covering the adhesive layer A was peeled off to expose the adhesive layer A, and a vapor deposition film approximately 20 nm thick was formed on the surface of the adhesive layer A using Vacuum Devices' "MSP15" under the conditions of target: Pt-Pd, operating time: 1 minute, thereby eliminating the tackiness. Four samples from which the tack has been removed are stacked together, and a circular hole with a radius of 5 mm is cut out from the center using a Thomson die to form a measurement sample. The test sample was placed on the glass plate of a Beck smoothness meter (manufactured by Kumagaya Riki Kogyo Co., Ltd.) with the adhesive layer A side of the test sample in contact with the glass plate, and the hole in the test sample was positioned directly above the central circular hole on the glass plate. A rubber pressure plate was placed on top of the PET film on top of the test sample, and while applying a pressure of 0.1 MPa via a pressure plate, suction was applied from below the central circular hole in the glass member to reduce the pressure to -50.7 kPa. When -50.7 kPa was reached, the pressure reduction was stopped, and Condition 1: the time required for the pressure to change from -50.7 kPa to -48.0 kPa, and Condition 2: the time required for the pressure to change from -50.7 kPa to -29.3 kPa were measured five times, the average value was calculated, and then divided by 4, the number of sheets stacked. If any of the five measurements exceeded 2000 seconds, the measurement was terminated and the value was recorded as ">2000" in the table.

[0098] <Rc、Rδc、Rku> Measurements were carried out using a digital microscope (Keyence VHX-7000) based on JIS B 0601 (2013).

[0099] [Evaluation of adhesive sheets] <Ease of application (position adjustment)> The procedure will be explained according to Figure 8. As shown in Figure 8-1, the adhesive sheets for fixing polishing pads with release sheets prepared in the Examples and Comparative Examples were cut to a size of 210 mm square, the release sheet FB was peeled off to expose the adhesive layer B, and this was attached to a 200 mm square smooth glass plate (approximately 300 g) with a thickness of 3 mm in an atmosphere of 23 ° C and 50% RH, and the adhesive sheet that protruded from all sides of the glass plate was removed with a cutter to obtain a sample for evaluating the attachment workability (hereinafter referred to as the sample) with a configuration of 200 mm square [glass / adhesive sheet / release sheet FA]. Note that in Figure 8, the stacking state of the adhesive sheet and the stacking state of the adhesive sheet and the release sheet FA are omitted. As shown in Figure 8-2, two types of frame lines, 200 mm square and 150 mm square, were drawn in the approximate center of one side of a 300 mm square glass plate with a 1 mm thick oil-based marker to form the substrate for evaluation (hereinafter referred to as the substrate). As shown in Figure 8-3, peel off the release sheet FA from the sample to expose the adhesive layer A, and place the 200mm square sample on the adherend so that each of its two sides extends at least 10mm beyond the two sides of the 200mm square outer frame drawn on the adherend. The surface on which the sample is placed should be the opposite side to the side on which the two frames are drawn. Immediately after placement, the sample was peeled off from the adherend, and as shown in Figure 8-4, the position was adjusted to fit within the 200 mm square frame of the adherend, and the time it took to re-attach it (placement - peeling - re-attachment) was measured. Five randomly selected people performed the work, and each was given a score as follows, and the application workability was evaluated from the total score of the five people. The ease of application was scored as follows: 3 points: Easily aligned to the frame within 10 seconds. 2 points: Alignment was achieved in more than 10 seconds but less than 15 seconds. 1 point: Alignment was achieved in more than 15 seconds but less than 30 seconds. 0 points: It took more than 30 seconds. The evaluation criteria for the ease of application are as follows. S:13-15 points A:10-12 points B: 7-9 points C: 4-6 points D: 0-3 points

[0100] <Evaluation of air release> As shown in Figure 9-1, immediately after completing the evaluation of lamination workability, a 500g weight for a top-pan balance, 41mm in diameter x 63mm in height, was placed on the center of the five evaluation samples and allowed to stand for 180 seconds. Next, as shown in Figure 9-2, the weight was removed, and the number of air pockets 5mm or larger in diameter within the 150mm square frame from the adherend side (the backside of the 300mm square glass plate) and the presence or absence of air pockets 10mm or larger were scored as follows. Air release ability was then evaluated from the total score of the five plates. The air release properties were scored according to the following criteria: 3 points: No air pockets with a diameter of 5mm or more within the frame 2 points: There are 1 or 2 air pockets with a diameter of 5 mm or more within the frame, and no air pockets with a diameter of 10 mm or more. 1 point: There are 3 to 5 air pockets with a diameter of 5 mm or more within the frame, and no air pockets with a diameter of 10 mm or more. 0 points: There are more than five air pockets with a diameter of 5 mm or more within the frame, and one air pocket with a diameter of 10 mm or more. The evaluation criteria for air release properties are as follows: S:13-15 points A:10-12 points B: 7-9 points C: 4-6 points D: 0-3 points

[0101] [Preparing adhesive samples to measure adhesive performance] <Evaluation of the initial adhesive strength of adhesive layer A> The release sheet FB was peeled off from the adhesive sheet for securing a polishing pad at 23°C and 50% RH. The exposed adhesive layer B was bonded to a 25 μm PET film and cut to a size of 25 mm wide x 100 mm long to prepare a sample for adhesive strength evaluation. The release sheet FA was then peeled off, and the exposed adhesive layer A was placed on a stainless steel plate and pressed against the stainless steel plate using a 2 kg roller. After leaving the sample for 24 hours, the adhesive strength of the adhesive layer A (to SUS) was measured using a tensile tester at 23°C and 50% RH at a peel angle of 180° and a peel speed of 0.3 m / min according to the JIS Z1528 method. The measured values ​​are shown in Table 1.

[0102] <Chemical resistance evaluation> The release sheet FA was peeled off from the adhesive strength evaluation sample, and the exposed adhesive layer A was placed on a stainless steel plate and pressed against the stainless steel plate using a 2 kg roller. Within 30 minutes, the sample was immersed in a pH 11.5 sodium hydroxide solution while still attached to the stainless steel plate and left for 24 hours at 40°C. The sample was then removed from the sodium hydroxide solution, washed with water, and left for 1 hour in an atmosphere of 23°C and 50% RH. The adhesive strength was measured in the same manner as in the above <Measurement of initial adhesive strength>, and this was taken as the <Adhesive strength after immersion>. The difference between the initial adhesive strength and the adhesive strength after immersion was calculated. The smaller this difference, the better the chemical resistance. The evaluation criteria for chemical resistance are as follows: A: The difference in adhesive strength is 1.5N / 25mm or less, very good B: The difference in adhesive strength is 1.5N / 25mm or more and less than 2.0N / 25mm. Good C: Adhesive strength difference is 2.0N / 25mm or more, less than 3.0N / 25mm. Practical. D: Adhesive strength difference is 3.0N / 25mm or more. Cannot be used. Chemical resistance is highly required in CMP processing, which uses various chemicals depending on the object being polished. S is the best, A is suitable for use, B is for general use, C has limited uses, and D cannot be used.

[0103] <Evaluation of holding power> The release sheet FA was peeled off from the adhesive strength evaluation sample, and only a 25mm wide x 25mm long area of ​​the exposed adhesive layer A was placed on a stainless steel plate. A 2kg roller was rolled back and forth once to press the adhesive layer A onto the stainless steel plate, and the sample was then left for 20 minutes in an atmosphere of 23°C and 50% RH. A 1kg weight was then attached to the edge of the sample not attached to the stainless steel plate in an 80°C atmosphere, applying a force at 180°. After 24 hours, the deviation in the adhesion position was measured in millimeters. If the sample completely fell off the adherend, the time until it fell off was measured. The evaluation criteria for holding power are as follows: S: Deviation is less than 0.1 mm A: 0.1mm or more, less than 1.0mm B: Misalignment is 1.0 mm or more and 5.0 mm or less C: Falls after 180 minutes or more D: Falls in less than 180 minutes The smaller the slippage, the less likely it is to slip or peel off during polishing, and the stronger the polishing pad can be fixed, making it suitable for use in various polishing processes. S is the best, A is suitable for use, B is for general use, C has limited uses, and D cannot be used.

[0104] <Polishing precision> The release sheet FB was peeled off from the adhesive sheet for fixing the polishing pad with the release sheet attached, and the non-abrasive side of the polishing pad (CMP cloth, Φ200mm, normal type, manufactured by Musashino Electronics Co., Ltd.) was placed on the exposed adhesive layer B and bonded under the conditions of roll temperature: 80°C, pressure: 0.1MPa, speed: 1.0M / min to produce a polishing pad with an adhesive sheet. The polishing device used was the MA-200 manufactured by Musashino Electronics Co., Ltd. The release sheet FA was peeled off from the prepared polishing pad with adhesive sheet, and the exposed adhesive layer A was attached to an aluminum surface plate, and medium polishing was performed under the following conditions. (conditions) Table rotation speed: 100 rpm Head rotation speed: 105 rpm Polishing target: A 200 mm wafer (75 μm thick) with a polysilicon layer (500 nm) formed on its surface, cut into a 3 cm square specimen Polishing pressure: 10.0 kPa Polishing time: 15 min Polishing fluid: Musashino Electronics colloidal silica polishing agent #80 After polishing, the test piece was rinsed with water and water droplets were removed with air. The thickness of the polysilicon was then measured at three arbitrary points, one at the center and two other points, using an Otsuka Electronics film thickness measuring instrument FE-300. The polishing precision was evaluated based on the difference between the maximum and minimum film thicknesses, using the following criteria. S: Less than 10 nm A: 10nm or more, less than 20nm B: 20nm or more, less than 30nm C: 30nm or more, less than 50nm D: 50nm or more In CMP polishing, which requires precision, S is the best, A is preferably used, B is for general use, C has limited uses, and D cannot be used.

[0105] [Table 1] [Explanation of symbols]

[0106] 1: Adhesive sheet for fixing polishing pads 2: Adhesive sheet for fixing polishing pads with release sheet 3: Polishing pad with adhesive layer A 4: Polishing pad with release sheet and adhesive layer A A: Adhesive layer A FA: Release sheet covering the surface of adhesive layer A FA': precursor of FA B: Adhesive layer B FB: Release sheet covering the surface of adhesive layer B F: Sheet-shaped substrate PP: Polishing pad R1: Metal roll R2: Rubber roll SP: Surface plate E: Rubber pressure plate G: Flat glass H: Pressure plate PET:PET film < / fa-7> < / fa-2>

Claims

1. An adhesive sheet for fixing a polishing pad to a surface plate, comprising an adhesive layer A on one side of a sheet-like substrate and an adhesive layer B on the other side of the sheet-like substrate, wherein the surface of the adhesive layer A that is not in contact with the sheet-like substrate has irregularities, and in a Beck smoothness test: The surface smoothness determined by the following condition 1 is 1 to 100 seconds, The surface smoothness determined by the following condition 2 is 15 to 1125 seconds.

1. An adhesive sheet for fixing a polishing pad, comprising: Condition 1: Time required for pressure to change from −50.7 kPa to −48.0 kPa. Condition 2: Time required for pressure to change from -50.7 kPa to -29.3 kPa.

2. 2. The adhesive sheet for fixing a polishing pad according to claim 1, wherein the average height Rc of the surface irregularities of the adhesive layer A is 10 to 40 μm.

3. 3. The adhesive sheet for fixing a polishing pad according to claim 2, wherein the difference in cutting level Rδc of the contour curve of the surface irregularities of the adhesive layer A is 5 to 25 μm, and the kurtosis Rku is less than 3.

4. 4. The adhesive sheet for fixing a polishing pad according to claim 3, wherein the shape of the convex portions on the surface of said adhesive layer A in a plan view is irregular and shapeless.

5. 5. The adhesive sheet for fixing a polishing pad according to claim 4, wherein the adhesive layer A is an acrylic adhesive layer.

6. 10. A pressure-sensitive adhesive sheet for fixing a polishing pad with a release sheet, comprising the pressure-sensitive adhesive sheet for fixing a polishing pad according to claim 1 and a release sheet FA, The release sheet FA is in contact with the adhesive layer A, An adhesive sheet for fixing a polishing pad with a release sheet, characterized in that the material of the release sheet FA is a plastic film that does not contain paper.

7. The surface of the adhesive layer B that is not in contact with the sheet-like substrate is in contact with a release sheet FB, 7. The adhesive sheet for fixing a polishing pad with a release sheet according to claim 6, wherein the material of said release sheet FB is a plastic film containing no paper.

8. 8. The pressure-sensitive adhesive sheet with a release sheet for fixing a polishing pad in a roll form according to claim 6 or 7, which is wound into a roll and has a widthwise length of 1000 mm or less.

9. 8. The adhesive sheet for fixing a polishing pad with a release sheet according to claim 7, wherein the length of the short side is 1000 mm or less.

10. A polishing pad with an adhesive layer, comprising a polishing pad and the adhesive sheet for fixing a polishing pad according to claim 1, The polishing pad has an adhesive layer A, and the polishing pad and the adhesive layer B are in contact with each other.

11. A polishing pad with an adhesive layer, comprising a polishing pad and the adhesive sheet for fixing a polishing pad with a release sheet according to claim 6, The polishing pad is provided with a release sheet and an adhesive layer A, in which the polishing pad and the adhesive layer B are in contact with each other.

12. A method for fixing a polishing pad to a surface plate via an adhesive sheet, characterized in that the release sheet FA is peeled off from the polishing pad with the release sheet and adhesive layer A described in claim 11 and the adhesive layer A is attached to the surface plate.

13. A method for producing an adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB, the adhesive sheet comprising a release sheet FA, an adhesive layer A, a sheet-like substrate, an adhesive layer B, and a release sheet FB, The method comprises the following steps (1) to (4): (1) A step of applying an adhesive agent a to the surface of a release sheet FA having a release-treated surface with an average height Rc of irregularities of 12 to 42 μm to form an adhesive layer A. (2) A step of superposing a sheet-like substrate on the surface of the adhesive layer A that is not in contact with the release sheet FA. (3) A step of applying adhesive b to the release-treated surface of the release sheet FB to form an adhesive layer B. (4) A step of overlapping the surface of the adhesive layer B that is not in contact with the release sheet FB onto the surface of the sheet-like substrate that is not in contact with the adhesive layer A. The surface of the adhesive layer A that is not in contact with the sheet-like substrate has irregularities, and in a Beck smoothness test, The surface smoothness determined by the following condition 1 is 1 to 100 seconds, The surface smoothness determined by the following condition 2 is 15 to 1125 seconds. A method for producing an adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB. Condition 1: Time required for pressure to change from −50.7 kPa to −48.0 kPa. Condition 2: Time required for pressure to change from -50.7 kPa to -29.3 kPa.

14. A method for producing an adhesive sheet for fixing a polishing pad with release sheets FA and FB, comprising a release sheet FA, an adhesive layer A, a sheet-like substrate, an adhesive layer B, and a release sheet FB, The method comprises the following steps (5) to (8): (5) A step of applying adhesive a to one surface of the sheet-like substrate to form an adhesive layer A. (6) A step of superposing the surface of the adhesive layer A that is not in contact with the sheet-like substrate on the surface of the release sheet FA, the surface of which has been subjected to a release treatment and has an average height Rc of irregularities of 12 to 42 μm. (7) A step of applying adhesive b to the release-treated surface of the release sheet FB to form an adhesive layer B. (8) A step of overlapping the surface of the adhesive layer B that is not in contact with the release sheet FB onto the surface of the sheet-like substrate that is not in contact with the adhesive layer A. The surface of the adhesive layer A that is not in contact with the sheet-like substrate has irregularities, and in a Beck smoothness test, The surface smoothness determined by the following condition 1 is 1 to 100 seconds, The surface smoothness determined by the following condition 2 is 15 to 1125 seconds. A method for producing an adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB. Condition 1: Time required for pressure to change from −50.7 kPa to −48.0 kPa. Condition 2: Time required for pressure to change from -50.7 kPa to -29.3 kPa.

15. A method for producing an adhesive sheet for fixing a polishing pad with release sheets FA and FB, comprising a release sheet FA, an adhesive layer A, a sheet-like substrate, an adhesive layer B, and a release sheet FB, the method comprising the following steps (9) to (12): (9) A step of applying adhesive b to the release-treated surface of the release sheet FB to form an adhesive layer B. (10) A step of superposing a sheet-like substrate on the surface of the adhesive layer B that is not in contact with the release sheet FB. (11) A step of applying adhesive a to the surface of a release sheet FA having a release-treated surface with an average height Rc of irregularities of 12 to 42 μm to form an adhesive layer A. (12) A step of overlapping the surface of the adhesive layer A that is not in contact with the release sheet FA onto the surface of the sheet-like substrate that is not in contact with the adhesive layer B. The surface of the adhesive layer A that is not in contact with the sheet-like substrate has irregularities, and in a Beck smoothness test, The surface smoothness determined by the following condition 1 is 1 to 100 seconds, The surface smoothness determined by the following condition 2 is 15 to 1125 seconds. A method for producing an adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB. Condition 1: Time required for pressure to change from −50.7 kPa to −48.0 kPa. Condition 2: Time required for pressure to change from -50.7 kPa to -29.3 kPa.

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