Adhesive sheet for fixing a polishing pad, polishing pad with adhesive layer A, and method for fixing a polishing pad to a surface plate

Abstract

To provide a double-sided adhesive sheet with a release sheet for fixing a polishing pad with a release sheet for high-precision CMP processing, which has little fluctuation in polishing performance even after repeated use, excellent air release properties, and excellent adhesive properties, and is used to fix a polishing pad to a surface plate. [Solution] An adhesive sheet for fixing a polishing pad with a release sheet FA, comprising an adhesive layer A on one side of a sheet-like substrate and an adhesive layer B on the other side, with the other surface of adhesive layer A in contact with a release sheet FA, wherein the outer surface of the release sheet FA has irregularities, has a regular and defined shape in a plan view, the average height Rc of the irregularities on the front surface is 5 to 25 μm, the material of the release sheet FA is a plastic film, and the Beck smoothness of the outer surface as measured under specific condition 1 is 0.1 to 30 seconds, and the Beck smoothness as measured under specific condition 2 is 1 to 500 seconds.

Description

[Technical Field]

[0001] The present invention 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 having 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 contacts the surface platen to allow air to pass through. However, even if air channels are created, the soft adhesive layer can block the air channels when the polishing pad is firmly fixed to the surface platen, preventing complete void removal. Furthermore, if it takes a long time for the air to escape, semiconductor production speed may be slowed. Furthermore, in CMP, the polishing pad attached to the surface platen is reused 100 to 1,000 times, so maintaining the polishing quality (removal volume) over multiple uses is considered the most important factor in terms of manufacturing costs.

[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 surface plate, which is intended for high-precision CMP processing, and which is easy to adjust the position when reattached, has excellent air release properties, has excellent adhesive properties, and exhibits stable polishing performance even after repeated polishing. [Means for solving the problem]

[0009] The present invention has solved the above problems by setting the smoothness of the outer surface of the release sheet FA 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, An adhesive sheet for fixing a polishing pad with a release sheet FA, 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 adhesive layer A not in contact with the sheet-like substrate being in contact with the release sheet FA, The shape of the convex portions on the outer surface of the release sheet FA in a plan view is regular and fixed, The average height Rc of the irregularities on the outer surface of the release sheet FA is 5 to 25 μm, The release sheet FA is made of plastic, The outer surface of the release sheet FA that is not in contact with the adhesive layer A has irregularities, and in a Beck smoothness test, The smoothness of the outer surface of the release sheet FA as determined by the following condition 1 is 0.1 to 30 seconds, The smoothness of the outer surface of the release sheet FA as determined by the following condition 2 is 1 to 500 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 an adhesive sheet for fixing a polishing pad with a release sheet FA according to [1] above, characterized in that the difference in cutting level Rδc of the contour curve of the surface irregularities on the outer side of the release sheet FA is 1 to 10 μm. [3] The present invention relates to an adhesive sheet for fixing a polishing pad with a release sheet FA according to [1] or [2] above, wherein the adhesive layer A is an acrylic adhesive layer.

[0012] [4] The present invention provides a polishing pad fixing adhesive sheet with a release sheet FA according to any one of [1] to [3] above, and a release sheet FB, The release sheet FB is in contact with the surface of the adhesive layer B that is not in contact with the sheet-like substrate, The present invention relates to an adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB, characterized in that the release sheet FB is made of plastic.

[0013] [5] The present invention relates to a roll-shaped adhesive sheet for fixing a polishing pad with a release sheet FA according to any one of [1] to [4] above, which is wound into a roll and has a width direction length of 1000 mm or less.

[0014] [6] The present invention relates to a roll-shaped adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB according to [4], which is wound into a roll and has a width direction length of 1000 mm or less.

[0015] [7] The present invention relates to an adhesive sheet for fixing a polishing pad with the release sheet FA and release sheet FB according to [4] above, which has a short side length of 1000 mm or less.

[0016] [8] The present invention provides a polishing pad with an adhesive layer, comprising a polishing pad and an adhesive sheet for fixing a polishing pad with a release sheet FA according to any one of [1] to [7] 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.

[0017] [9] 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 [8] above, and the adhesive layer A is attached to the surface plate. [Effects of the Invention]

[0018] The present invention provides a double-sided pressure-sensitive adhesive sheet for fixing a polishing pad to a surface plate, which is easy to reposition, 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 with a release sheet FA of the present invention can improve workability during application and significantly improve polishing accuracy in high-precision CMP processing. Furthermore, the polishing pad with adhesive layer A of the present invention can exhibit stable polishing performance even when attached to a surface plate and used repeatedly for polishing. [Brief explanation of the drawings]

[0019] [Figure 1] Schematic cross-sectional view showing an embodiment of an adhesive sheet for fixing a polishing pad with a release sheet FA and its usage form. [Figure 2] FIG. 1 is a schematic diagram for explaining a Beck smoothness test. [Figure 3] FIG. 2 is an image diagram for explaining the unevenness (cross section) of the surface of the release sheet FA. [Figure 4] FIG. 2 is an image diagram illustrating the unevenness (cross section) of the surface of the release sheet. [Figure 5] 10 is an example of an image illustrating the unevenness of the outer surface of the release sheet FA. [Figure 6] FIG. 1 is a schematic diagram illustrating the "regularity" of the unevenness (in plan view) on the outer surface of the release sheet FA. [Figure 7] An image diagram to explain the "irregularity" of the unevenness (plan view) on the outer surface of the release sheet FA. [Figure 8] An example of a manufacturing method for an adhesive sheet for fixing a polishing pad with a release sheet FA, and a cross-sectional schematic diagram showing how it is used [Figure 9] FIG. 1 is a schematic diagram for explaining a method for evaluating lamination workability. [Figure 10] FIG. 2 is a schematic diagram illustrating a method for evaluating air release properties. DETAILED DESCRIPTION OF THE INVENTION

[0020] 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.

[0021] <Adhesive sheet for fixing polishing pads with release sheet FA> As shown in FIG. 1-1, the adhesive sheet 1 for fixing a polishing pad with a release sheet FA of the present invention comprises an adhesive sheet 0 for fixing a polishing pad (hereinafter also referred to as adhesive sheet) having adhesive layer A and adhesive layer B on both sides of a sheet-like substrate F, with the surface of adhesive layer A (the surface not in contact with the sheet-like substrate F) being in contact with and covered by the release surface of the release sheet FA to protect it. In the form of FIG. 1-1, as shown in FIG. 1-1', it is also possible to provide a roll-like form in which the adhesive sheet 1 for fixing a polishing pad with a release sheet FA is wrapped around a cylindrical member called a core (also called a core material), and the surface of adhesive layer B is covered with the other surface of the release sheet FA (the surface not in contact with adhesive layer A). Note that the unevenness of the surfaces of the release sheet FA and adhesive layer A is not shown in FIG. 1. The adhesive sheet 1 for fixing a polishing pad with a release sheet FA can also be provided in the form of an adhesive sheet 2 for fixing a polishing pad with a release sheet FA and a release sheet FB, which has a release sheet FB covering the surface of the adhesive layer B, as shown in Figure 1-2. As shown in FIG. 1-3, a polishing pad PP is laminated on the adhesive layer B of the adhesive sheet 1 for fixing a polishing pad with a release sheet FA attached thereto, thereby forming a polishing pad 3 with a release sheet FA attached thereto. Next, as shown in Figure 1-4, the release sheet FA is peeled off, and the polishing pad 4, with its adhesive layer A exposed, is attached to a surface plate SP. Adhesive layer A of the adhesive sheet O contacts the surface plate, and adhesive layer B contacts the polishing pad. In other words, the polishing pad PP is fixed to the surface plate SP via the adhesive sheet O, which has a layered structure of adhesive layer A / sheet-like substrate F / adhesive layer B.

[0022] When attaching a polishing pad PP to a surface platen via an adhesive sheet O, in many cases up until now, the polishing pad PP has been gently bent and flexed while the surface of the polishing pad PP is slowly squeezed from the edge with a roll or squeegee to push out the air from the edge. 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).

[0023] In the adhesive sheet for fixing a polishing pad with a release sheet FA of the present invention, the outer surface of the release sheet FA (the surface that will come into contact with the surface platen SP) has irregularities determined by Beck smoothness testing and surface roughness. The same irregularities as those on the outer surface of the release sheet FA are transferred to the adhesive layer A, and the recesses 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 surrounding area to the outside and to level the air across the entire adhesion interface. As a result, the occurrence of large localized air pockets between the surface platen and the adhesive sheet, which could impair the parallelism between the surface of the polishing pad (the surface that comes into contact with the polishing target) and the surface platen, can be suppressed or prevented.

[0024] The Beck smoothness of the outer surface of the release sheet FA will be described below. Beck smoothness is specified in JIS P8119:1998. 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.

[0025] 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 the adhesive layer B of the adhesive sheet, and then cut into a 50 mm square. Two 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 outer surface of the bottom release sheet FA 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 two overlapping adhesive sheets, half of the measured value is the result for adhesive layer A per adhesive sheet. In other words, if the measured value is 2 seconds, the Beck smoothness of the outer surface of the release sheet FA is 1 second.

[0026] Under condition 1, it is important that the Beck smoothness of the outer surface of the release sheet FA is 0.1 to 30 seconds, more preferably 0.5 to 20 seconds, particularly preferably 1.0 to 10 seconds, and most preferably 1.5 to 6 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 20 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 0.1 seconds, 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 0.1 seconds or more, it becomes easier to maintain the position of the polishing sheet adhered to the surface plate.

[0027] Furthermore, it is important that the Beck smoothness of the outer surface of the release sheet FA is 1 to 500 seconds under condition 2, more preferably 20 to 200 seconds, even more preferably 30 to 150 seconds, and most preferably 40 to 100 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 400 seconds or less, even if localized air accumulation occurs between the surface plate and adhesive layer A, it becomes easier to equalize the air over the entire adhesive interface through the recesses in the adhesive interface or to release the air from the periphery. When the smoothness of condition 2 is 1 second or more, adhesive layer A that comes into contact with the surface plate adheres more firmly to the surface plate. Being within the preferred range means that the surface plate is smooth and tightly adhered without any wrinkling, while the gaps gradually disappear over a period of several tens of minutes without any special treatment, making it suitable for the CMP polishing process, which requires high precision. Being within a more preferred range means that the surface has high adhesion while also having ventilation holes large enough to prevent slurry from penetrating between adhesive layer A and the surface plate during polishing, thereby suppressing deterioration of the adhesive layer and preventing lifting and swelling. This allows the polishing pad to be used repeatedly, reducing variations in polishing lots.

[0028] The surfaces of the release sheet FB and the adhesive layer B (the surfaces that will come into contact with the polishing pad) do not need to have any particular irregularities. When the polishing pad 3 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 1 for fixing a polishing pad with the release sheet FA attached, 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.

[0029] The shape of the unevenness (cross section) on the surface of the release sheet FA will be described below. Note that since the adhesive layer A has a reversed pattern transferred from the outer surface of the release sheet FA, it has the same shape as the outer surface of the release sheet FA. The upper side of the cross section shown in the figure is in contact with adhesive layer A, and the lower side is the outside of release sheet FA. For the sake of explanation, the side of release sheet FA that is in contact with adhesive layer A is called the inside of release sheet FA, and the side that is not in contact is called the outside of release sheet FA. In order to ensure reliable ventilation holes without completely crushing the surface of adhesive layer A even after it has been attached to the surface plate, it is preferable that the corners of the outer convex parts of release sheet FA be angular as shown in Figure 3-1 rather than rounded as shown in Figure 3-3. This is because when pressure is applied to the surface of adhesive layer A that corresponds to the shape of the outer convex parts of release sheet FA, pressure is concentrated at the corners of the convex parts, and the angular shape prevents them from being completely crushed and flattened. Furthermore, the larger the contact area ratio between the adhesive surface and the surface plate, the more the parallelism between the surface plate and the polishing pad is maintained, thereby improving polishing accuracy and suppressing variations in the polishing lot. In terms of this, Figure 3-1, in which the convex portion on the outside of the release sheet FA is wider than the concave portion (i.e., the convex portion of the adhesive layer A is wider), is preferable to Figure 3-2, and Figure 3-3 is preferable to Figure 3-4.

[0030] Therefore, to improve air release and alignment without reducing polishing accuracy, it is important that the average height Rc of the roughness curve elements on the outer surface of the release sheet FA (hereinafter referred to as "average height Rc") be 5 to 25 μm, preferably 7 to 20 μm, and more preferably 10 to 15 μm. This range allows the unevenness of the surface of the adhesive layer A to be reproduced with high accuracy. When the average height Rc of the outer surface of the release sheet FA is 5 μm or more, the concave portions become relatively deep, improving the breathability of the surface of the adhesive layer A under both conditions 1 and 2 of the Beck smoothness test, improving alignment and air release. This has a particularly large effect on air release, making it easier to remove the polishing pad and the adhesive sheet from the surface plate after polishing. When the average height Rc of the outer surface of the release sheet FA is 25 μm or less, the adhesive layer A that reproduces such an average height Rc is less likely to affect the outermost surface of the polishing pad that contacts the workpiece when attached to a surface plate for polishing, resulting in excellent polishing accuracy. Furthermore, the depressions formed on the adhesive surface are not easily crushed even when the adhesive layer is deformed during application, and the depressions on the adhesive layer surface, which act as vents, are kept uniform without being partially blocked, making it easier to remove slurry that has partially penetrated, improving polishing accuracy.Furthermore, by being in a more preferred range, the size of the vents becomes more difficult for slurry to penetrate while maintaining the above-mentioned polishing accuracy and air escape, so that even when polishing lots are repeated (a new polishing target is polished without changing the polishing pad), differences in the polishing rate (polishing amount) between polishing lots are less likely to occur, which is preferable.

[0031] The shape of the irregularities on the outer surface of the release sheet FA of the present invention, such as the roundness and inclination of the convex portions and the spacing between the irregularities, can be more specifically understood from the difference in cutting level of the contour curve: Rδc. Rδc is preferably 1 to 10 μm, more preferably 2 to 7.5 μm, and even more preferably 4 to 6 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 length of the substantial part 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%. In particular, Rδc, which is expressed when the load length ratio is 0% and 50%, indirectly indicates the depth and frequency of unevenness and the slope of the convexities. By making the Rδc of the outer surface of the release sheet FA 1 μm or more, air trapping is less likely to occur in the very early stages of application, making it easier to suppress variations between polishing lots (lot fluctuations). In other words, the adhesive layer does not adhere very firmly to the surface plate, so that when adhesive layer A is peeled off from the surface plate once it has come into contact with it, it can be peeled off with little resistance, making it easy to adjust the position. By the way, since adhesive layer A is adhesive, it is thought that it will deform to some extent when it is attached to the surface plate. In other words, it is thought that microscopically, when it is attached, the convex parts on the surface of adhesive layer A are crushed, albeit slightly, and the concave parts become somewhat shallower in comparison. When Rδc is 10 By making the thickness of the adhesive layer A equal to or less than μm, even if the adhesive layer A is crushed when the adhesive layer A is firmly attached to the surface plate, the recesses are reliably maintained, thereby improving air release properties.

[0032] Rc and Rδc will be explained using schematic diagrams. Note that the following explanation is for the lower side of each diagram (the outside of the FA of the adhesive sheet for fixing a polishing pad with the release sheet FA attached). Figures 3-1, 3-2, and 3-3 show cases where Rc is about the same. If Figure 3-1 shows a case where Rδc is 1 to 10 μm, then in Figure 3-2, where the convex portion on the underside corresponding to the vent is wider than in Figure 3-1 and the concave portion on the underside corresponding to the area where the adhesive layer touches the adherend is narrower, Rδc will be larger than in Figure 3-1. In Figure 3-3, Rδc will be even larger than in Figure 3-2.

[0033] Rc and Rδc are values ​​measured based on JIS B 0601 (2013), and can be measured using a laser microscope (Keyence VK-X100). Figure 5-1 shows an example of an image of the outer surface of the release sheet FA observed with a laser microscope. In the upper image of Figure 5-1, the straight lines are recesses, and the triangular areas surrounded by the straight lines are protrusions, forming a regular, fixed shape in plan view. Specifically, at 100x magnification, six consecutive images were taken in each direction across a field of view approximately 950 μm long and 1300 μm wide (36 images in total), with the entire observation field measuring approximately 5700 μm long and 7800 μm wide. The measurement field was an area approximately 5500 μm long and 7500 μm wide in the center of the entire observation field. Measurement lines were set along one and two diagonal lines across the field of view, and Rc and Rδc were measured and averaged. If the diagonal lines of the measurement field of view are located directly above a convex portion, as in the lower diagram of Figure 5-2, measurement lines were set approximately parallel to the diagonal lines, spanning as many concave and convex portions as possible (e.g., five or more). Similarly, horizontal measurement lines were set approximately parallel to the field of view, spanning as many concave and convex portions as possible, to avoid measuring only directly above the convex portions. The same applies to the measurement of Rc etc. of the release sheet FA described later.

[0034] A cross-sectional image of the unevenness on the outer surface of the release sheet FA of the present invention is shown in FIG. 4-1, and a cross-sectional image of the unevenness of the so-called "mat" is shown in FIG. 4-2. The unevenness of the present invention differs from the so-called "mat" unevenness intended to achieve an optically matte finish, and the unevenness elements (spacing, depth) on the outer surface of the release sheet FA of the present invention are significantly larger. Because the "mat" unevenness elements are significantly smaller, it is difficult to transfer the uneven shape of the outer surface of the release sheet FA directly to the adhesive layer A. Even if it were transferred to the adhesive layer A, the Rc and Rδc of the present invention form unevenness on the adhesive layer A with a larger difference in height and wider spacing between the unevenness than the so-called "mat" that is generally good at achieving an optically matte finish. This creates an ideal shape for initial positioning adjustment after application, air release during application, and for fixing the polishing pad to the surface plate in a parallel and smooth manner.

[0035] The "regularity" of the unevenness (in plan view) on the outer surface of the release sheet FA will be explained below. Examples of the irregularities (in plan view) on the outer surface of the release sheet FA in the present invention include regular patterns and designs such as a grid pattern as shown in Figure 6-1 and polka dots as shown in Figures 6-2 and 6-3. In the figures, black or shaded areas indicate recesses. Figure 6-2(a) shows a case where the outer surface of the release sheet FA has a regular polka dot pattern consisting of independent circular depressions and continuous projections. Figure 6-2(b) is a cross-sectional view taken along X-X' in Figure 6-2(a). The top surface in the figure represents the outer surface of the release sheet FA, and the bottom surface represents the inner surface of the release sheet FA. The inner surface of the release sheet FA has the same degree of unevenness as the outer surface of the release sheet FA. Figure 6-2(c) is a cross-sectional view of adhesive layer A to which the unevenness of the inner surface of the release sheet FA has been inversely transferred. The surface of adhesive layer A reproduces the unevenness of the outer surface of the release sheet FA. When the outer surface of the release sheet FA has continuous depressions as in Figure 6-2(a), independent depressions are formed in adhesive layer A as shown in Figure 6-2(c). On the other hand, when the outer surface of the release sheet FA has a regular polka dot pattern consisting of independent circular convex portions and continuous concave portions as shown in Figure 6-3(a), the surface of the adhesive layer A formed by the reverse transfer of the concave and convex portions on the inner surface of the release sheet FA has continuous concave portions as shown in Figure 6-3(c), which reach the edge of the adhesive sheet. From the viewpoint of ensuring air flow paths in the adhesive layer, it is preferable that the concave and convex portions on the outer surface of the release sheet FA have independent convex portions and continuous concave portions all the way to the edge. This also applies to triangles and polygons, in addition to polka dot patterns. Furthermore, as shown in FIG. 6-4, the outer surface of the release sheet FA may have identical or similar patterns overlapping each other, with the convex portions being independent and the concave portions being continuous. As shown in FIG. 6-5, a release sheet FA in which continuous grid-shaped recesses and continuous circular recesses overlap each other can also be exemplified.

[0036] Figure 7 shows an example where the unevenness (in plan view) of the outer surface of the release sheet FA is irregular and has an indeterminate shape. The black areas indicate convex parts and the white areas indicate concave parts, and there is no regularity in their position or shape.

[0037] As long as the Beck smoothness of the outer surface of the release sheet FA in an adhesive sheet for fixing a polishing pad with a release sheet FA is within the above range under conditions 1 and 2, there is no difference in terms of positioning when affixing to a surface plate or air release properties whether the shape of the unevenness in a planar view is irregular and amorphous or regular and amorphous. However, because the patterns and designs in plan view are regular and fixed, it is easier to find gaps or unevenness that may occur if air gets in and disrupts the regularity during application, and this is preferable because it makes it easier to detect defects during the process using a CCD camera or similar device.

[0038] One method for obtaining an adhesive sheet for fixing a polishing pad with a release sheet FA 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 5 to 25 μm. That is, a pre-release sheet FA' having a release layer is prepared, and then, as shown in Figure 8-1, the pre-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 5 to 25 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. When measuring the Beck smoothness of an adhesive sheet with a release sheet FA formed using such an uneven surface, the unevenness of the outer surface of the release sheet FA is deformed (crushed) by the application of pressure during measurement. The deformation of the unevenness of the outer surface of the release sheet FA is affected by the thickness and hardness of the adhesive layer FA in contact with the inner surface of the release sheet FA. For example, for the same type of adhesive layer, the thicker the layer, the easier it is to relax stress, so the unevenness of the outer surface of the release sheet FA is crushed to a smoother shape, resulting in a higher Beck smoothness value for the adhesive sheet with a release sheet FA. The Beck smoothness of an adhesive sheet with a release sheet FA is a value that takes into account the deformation of the unevenness of the outer surface of the release sheet FA and the deformation of the unevenness of the adhesive layer FA in contact with the inner surface of the release sheet FA due to pressure application. Therefore, the Beck smoothness value of an adhesive sheet with a release sheet is related to the ease of application and air release when applying the adhesive layer A to a surface plate, the adhesive strength and holding power to the surface plate, and polishing accuracy.

[0039] 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 sheet can be produced, having a layered structure of [release sheet FA / adhesive layer A / sheet-like substrate F / adhesive layer B / release sheet FB] as shown in Figure 8-2.

[0040] 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 5 to 25 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 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 8-2.

[0041] 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 5 to 25 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 8-2. 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.

[0042] 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.

[0043] By peeling off the release sheet FB from an adhesive sheet for fixing a polishing pad with a release sheet FA and release sheet FB 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 8-3, 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, the release sheet FA covering the adhesive layer A is peeled off from the resulting polishing pad 4 with the release sheet and adhesive layer, yielding a polishing pad 3 with an adhesive layer A onto which the unevenness of the inner surface of the release sheet FA is inversely transferred. Then, as shown in Figure 8-4, the exposed adhesive layer A can be attached to a surface plate SP, thereby fixing the polishing pad PP to the surface plate SP via the adhesive sheet.

[0044] <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, and the number of layers is not particularly limited. 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. A thickness of 15 μm or more for the adhesive layer A facilitates the development of adhesive strength. Furthermore, the thicker the thickness, the more likely the unevenness of the adhesive layer A formed by the use of the release sheet FA is to be crushed, resulting in poor breathability when attached to a surface plate. Therefore, a thickness of 100 μm or less facilitates the maintenance of the desired uneven shape of the present invention even under pressure during the polishing process. A thickness within this more preferred range provides excellent adhesion 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 and 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.

[0045] 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.

[0046] <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.

[0047] <(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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] The weight-average molecular weight (Mw) of the acrylic copolymer is preferably 200,000 to 1,800,000, and more preferably 500,000 to 1,500,000. 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 1,800,000 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.

[0052] 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.

[0053] <Elastomer-based adhesive> The elastomeric pressure-sensitive adhesive contains an elastomer and a tackifying resin. The elastomer preferably contains a styrene-isoprene block copolymer.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] <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.

[0059] <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.

[0060] <Curing agent> 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.

[0061] <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.

[0062] The adhesive strength of the adhesive layer A on the platen side before immersion is not particularly limited, but is preferably 5N / 25mm to 25N / 25mm, and particularly preferably 15N / 25mm to 20N / 25mm. Furthermore, it is preferable that the change in adhesive strength after polishing is small. That is, the smaller the change in adhesive strength after immersing the adhesive layer while attached to the stainless steel plate in a sodium hydroxide aqueous solution with a pH of 11.5 and leaving it in an environment of 40°C for 24 hours, the more preferable. In particular, the adhesive strength after immersion in an alkaline aqueous solution tends to increase as the cohesive strength decreases due to swelling of the adhesive layer. As a countermeasure, the decrease in cohesive strength can be suppressed by increasing the crosslink density with a curing agent, but this results in a trade-off in performance, as the adhesive strength before immersion decreases. Compared to a so-called grained pattern, in which the surface unevenness of the adhesive layer is irregular and amorphous, a grid pattern makes it easier to flatten the surface of the convex parts of the adhesive layer that come into contact with the base plate, so the contact area ratio with the object to be adhered is less likely to change due to external factors such as swelling or load immediately after bonding, and the wafer polishing accuracy and polishing rate are less likely to change even when polishing wafers multiple times, making it preferable in that it increases the number of times the polishing pad can be used. Considering the stability of the polishing pad and the stability of the polishing process after application, the initial adhesive strength is preferably 5 N / 25 mm or more, and less than 30 N / 25 mm from the viewpoint of ease of repositioning (alignment) during application. A strength of 10 to 20 N / 25 mm is particularly preferred from the viewpoints of ease of alignment and resistance to shifting and peeling even under various stresses during the polishing process. The adhesive strength in the present invention refers to the value measured by placing the surface to be measured on a stainless steel plate, rolling a 2 kg roller back and forth once to press adhesive layer A onto the stainless steel plate, leaving it for 24 hours, and then measuring the value using a tensile tester in an atmosphere of 23°C-50% RH at a peel angle of 180 degrees and a peel speed of 0.3 m / min in accordance with the measurement method of JIS Z1528:2009.

[0063] Adhesive layer A has 0.5cm of adhesive layer that adheres to the surface plate when bonding to ensure air release and fixation to the surface plate. 2The contact area ratio per pad is preferably 60 to 90%, more preferably 62 to 80%, and particularly preferably 65 to 75%. A contact area ratio of 60% or more makes it difficult for adhesion to change immediately after fixing to the surface plate and during polishing, and when polishing is repeatedly performed by changing the object to be polished without changing the polishing pad attached to the surface plate, variations in the amount of polishing per polishing lot are unlikely. A contact area ratio of 90% or less makes it possible to achieve excellent air escape properties and suppress voids during application. As will be described later, the contact area ratio is determined by peeling off the release sheet FA of the adhesive sheet, bonding the exposed adhesive layer A to the metal-deposited surface of the separator with a hand roller, and then rolling a 2 kg roller back and forth once. Then, the surface of the separator side is observed at random different locations with a digital microscope (Keyence Corporation) at 20x magnification (field of view area: approximately 1.0 cm) using a coaxial light source. 2 ) and take three images. The ratio of areas with and without a identifiable evaporated film in the images is the average value of the three images, which indicates the percentage of areas with an evaporated film.

[0064] <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 a plastic film or synthetic paper whose main material is a plastic such as polypropylene. For CMP processing, a release sheet made of a highly clean plastic film as a sheet-like substrate is preferred. As a plastic film for the release sheet FA, an inexpensive polyethylene terephthalate film is preferred, as it can be easily textured with a metal roll. Furthermore, textured with a metal roll is preferred because it is less prone to foreign matter contamination and results in a cleaner product than cutting or laser processing. For textured processing with a metal roll, as exemplified above, a release sheet having a thickness of 25 to 100 μm is preferably used, with a thickness of 45 μm to 80 μm being more preferred. By using a thickness within this range, it is easy to transfer the same shape as the desired shape formed on the metal surface onto the release sheet (transferability), and the outer and inner sides of the release sheet FA have the same reversed shape (reversibility), so that the pattern on the surface of the adhesive layer A formed by applying it to the inner side of the release sheet FA is the same as the pattern on the inner side of the release sheet FA. Invert Through a series of processes, such as forming the metal roll into a desired shape, the uneven pattern of the metal roll can be transferred to the surface of the adhesive layer A with good reproducibility. In order to transfer the unevenness on the inside of the release sheet FA to the surface of the adhesive layer A, the average height Rc of the outside of the release sheet FA is preferably 5 to 25 μm, more preferably 7 to 20 μm, and even more preferably 10 to 15 μm. By being in the preferred range, the unevenness can be reproduced on the adhesive layer A with high precision.

[0065] 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 used in the release sheets FA and FB include silicone resins, alkyd resins, melamine resins, fluorine resins, and acrylic resins, with silicone resins being preferred.

[0066] <Sheet-shaped substrate> The sheet-like substrate of the present invention is preferably a nonwoven fabric or a plastic film. Examples of plastic films 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] <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 8-2, 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 adhesive sheet for fixing a polishing pad 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.

[0071] As shown in Figures 1-4 and 8-3, 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 3 with release sheet FA and adhesive layer A is formed. Next, as shown in Figures 1-4 and 8-4, 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 the surface plate SP. The adhesive layer A of the adhesive sheet 0 for fixing a polishing pad contacts the surface plate, and the adhesive layer B contacts the polishing pad.

[0072] 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 outermost 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]

[0073] 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".

[0074] [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.

[0075] [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.

[0076] (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 n-butyl acrylate (BA), 120 g of 2-ethylhexyl acrylate (2-EHA), 10 g of acrylic acid (AA), 5 g of hydroxyethyl acrylate (HEA), and 0.5 g of azobisisobutyronitrile (AIBN) 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%).

[0077] <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, 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 allowed to react 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%).

[0078] <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).

[0079] <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%).

[0080] Peel-off sheet <fa-1>Manufacturing A PET release sheet "RF2PETCS001-50" (50 μm thick, silicone release-treated on one side, Rc: 0.2 μm) manufactured by Aim Co., Ltd., measuring approximately 30 cm × 30 cm, was prepared as a pre-release sheet. The pre-release sheet was passed between a metal roll and a rubber roll bearing a lattice pattern (area of ​​the lattice surface corresponding to the mold recesses: 2.4 mm, width of the lines of the mold protrusions: 200 μm, height of the mold protrusions: 8 μm) as shown in Figure 6-1 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 bearing the lattice pattern. Measurement was performed using a laser microscope (Keyence VK-X100) using the above method. Peel-off sheet <fa-1> outer surface< / fa-1> Rc was 5.2 μm. The thickness of the PET release sheet was measured at five random points using a Litematic VL-50B thickness gauge (manufactured by Mitutoyo Corporation) with a Φ7.5 mm probe and a pressure of 0.01 N, and was calculated as an average value.

[0081] Peel-off sheet <fa-2> ~ <fa-5>Manufacturing Release sheets FA-2 to FA-5 were obtained under the same processing conditions as for release sheet FA-1, except that the recesses of the metal roll used to produce release sheet FA-1 were further cut and the protrusions were made higher.

[0082] Peel-off sheet <fa-6>Manufacturing Instead of the metal roll used to manufacture the release sheet FA-1, a pattern with a grid and diagonal convexities as shown in Figure 5-1 (area of ​​the triangular mold concaves: 0.9 mm 2 The sheet was passed between a metal roll with a mold projection line width of 200 μm and a rubber roll (mold projection line width: 200 μm, mold projection height: 6 μm) at a temperature of 220°C, a pressure of 5 MPa, and a speed of 3 m / min to obtain a release sheet FA-6 with the grid pattern transferred thereon.

[0083] Peel-off sheet <fa-7> ~ <fa-10>Manufacturing Release sheets FA-7 to FA-10 were obtained under the same processing conditions as for release sheet FA-6, except that the recesses of the metal roll used to produce release sheet FA-6 were further cut to make the protrusions higher.

[0084] Detailed release sheets FA-1 to FA-12 outer surface The Rc is as follows: FA-1 lattice pattern transfer. Rc: 5.2μm FA-2: The raised part of the lattice pattern mold used in FA-1 was made higher and transferred. Rc: 7.5 μm FA-3: The raised part of the lattice pattern mold used in FA-1 was made higher and transferred. Rc: 11.1 μm FA-4: The raised part of the lattice pattern mold used in FA-1 was made higher and transferred. Rc: 14.8 μm FA-5: The raised part of the lattice pattern mold used in FA-1 was made higher and transferred. Rc: 18.7 μm FA-6 Transfers grid and diagonal patterns. Rc: 5.4 μm FA-7: The convex parts of the lattice and diagonal pattern mold used in FA-6 were raised and transferred. Rc: 11.5 μm FA-8: The convex parts of the lattice and diagonal pattern mold used in FA-6 were raised and transferred. Rc: 14.5 μm FA-9: The convex parts of the lattice and diagonal pattern mold used in FA-6 were raised and transferred. Rc: 18.1 μm FA-10: The convex parts of the lattice and diagonal line patterns used in FA-6 were raised and transferred. Rc: 23.6 μm

[0085] <Release Sheet FB> FB-1 RF2PETCS001-50, manufactured by Aim Co., Ltd., PET release sheet (thickness: 50 μm, one side silicone release treatment, Rc: 0.2 μm)

[0086] <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 / m² using a coil bar on the matte side and the glossy side opposite. 2 Film coated and used as a release surface. Rc: 0.1 μm FH-22 Matte grade polyester film (Unitika, Emblet "PTH-38") was coated with BYK's silicone treatment agent "BYK300" at 0.1g / m² using a coil bar on the matte side opposite the gloss side. 2 Film coated and used as a release surface. Rc: 1.5 μm FH-23: Release sheet FH-23 was obtained in the same manner as in the production of FA-1, except that the temperature when passing the pre-release sheet between the metal roll and the rubber roll was 175°C. Rc: 3.2 μm FH-24: The raised part of the lattice pattern mold used in FA-1 was transferred. Rc: 43.2 μm

[0087] <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)

[0088] 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 pressure-sensitive adhesive sheet (Beck smoothness of the outer surface of the release sheet FA, average roughness Rc, and cut level difference Rδc of the profile curve) 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.

[0089] <Examples 2 to 10> 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, release sheets FA-2 to FA-10 were used to apply the solution of adhesive P-1 as shown in Table 1.

[0090] <Examples 11 to 15> 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-3 or FA-4 was used instead of release sheet FA-1, and a solution of adhesive P-4 was used instead of the solution of adhesive P-1 as shown in Table 1, the thickness of adhesive layer A was changed, the sheet-like substrate was changed, or the type and thickness of adhesive layer B was changed.

[0091] <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, release sheets FH-21 to FH-24 were used to apply the solution of adhesive P-1, as shown in Table 1.

[0092] [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, two samples are stacked on top of each other, and a 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 a glass plate with the outer surface of the release sheet FA in contact with the glass plate of a Beck smoothness meter (manufactured by Kumagaya Riki Kogyo Co., Ltd.) and the hole in the test sample 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. Condition 1: the time required for the pressure to change from -50.7 kPa to -48.0 kPa; Condition 2: the time required for the pressure to change from -50.7 kPa to -29.3 kPa; each were measured five times, and the average was calculated and divided by 2, representing the number of sheets stacked. If any of the five measurements exceeded 1000 seconds, the measurement was terminated and the value was recorded as ">1000" in the table. Furthermore, if the smoothness was low in even one of the five measurements, resulting in a measurement time of less than 0.1 seconds, or if the amount of air flowing in was too large and the vacuum did not reach -50.7 kPa, the table was marked with "0."

[0093] <Rc、Rδc> A vacuum device "MSP15" was used to form a vapor-deposited film approximately 20 nm thick on the surface of the sheet to be measured, with a target of Pt-Pd and an operating time of 1 minute, so that the laser from the laser microscope (Keyence VK-X100) would be reflected by the outermost surface of the sheet. Measurements were made using a laser microscope in accordance with JIS B 0601 (2013).

[0094] [Evaluation of adhesive sheets] <Ease of application (position adjustment)> The procedure will be explained according to Figure 9. As shown in Figure 9-1, 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 9-2, 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 using a 1 mm thick oil-based marker to form the substrate for evaluation (hereinafter referred to as the substrate). As shown in Figure 9-3, 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 the position was adjusted to fit within the 200 mm square frame of the adherend as shown in Figure 9-4, 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

[0095] <Evaluation of air release> As shown in Figure 10-1, 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 10-2, 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

[0096] [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 Z1528:2009 method. The measured values ​​are shown in Table 1.

[0097] <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 12 hours at 60°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: S: The difference in adhesive strength is less than 1.0N / 25mm A: The difference in adhesive strength is 1.0N / 25mm or more and less than 1.5N / 25mm B: The difference in adhesive strength is 1.5N / 25mm or more and less than 2.0N / 25mm C: The difference in adhesive strength is 2.0N / 25mm or more and less than 3.0N / 25mm D: The difference in adhesive strength is 3.0N / 25mm or more 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.

[0098] <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.

[0099] <Contact area ratio of adhesive layer A> Pt-Pd was vapor-deposited onto the release surface of the release sheet FB cut into a 4 cm square using a vacuum vapor deposition device (manufactured by JEOL Ltd.) to form a vapor-deposited film. The release sheet FA of the adhesive sheet cut into a 3 cm square was peeled off to expose the adhesive layer A, and the adhesive layer A and the vapor-deposited film of the release sheet FB, which was 4 cm square, were then bonded together using a hand roller, and a 2 kg roller was rolled back and forth once to prepare the measurement sample. The interface between the adhesive layer A and the 4 cm square release sheet FB was observed through the 4 cm square release sheet FB using a digital microscope (Keyence Corporation) with a coaxial light source at 20x magnification (field of view area of ​​approximately 1.0 cm). 2 ) and take three photographs. Each of the three photographed images was converted to monochrome and binarized using image processing software (GIMP), and the area ratio of the areas where the vapor-deposited film and adhesive layer A, shown in black in the image, were in close contact with each other to the areas where they were not in close contact was calculated, and the arithmetic mean value was calculated to obtain the contact area ratio (%).

[0100] <Evaluation of polishing lot differences> 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 polishing was carried out 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 washed with water, and the surface was blown with air to remove water droplets. Then, the thickness of one point in the center of the test piece was measured using an FE-300 film thickness measuring instrument manufactured by Otsuka Electronics. The polishing pad was not replaced, and only 10 objects to be polished were replaced and polished under the same conditions. The thickness of the 10 test pieces after polishing was measured, and the difference between the maximum and minimum film thickness was determined and evaluated according to the following criteria. S: Less than 40 nm A: 40nm or more, less than 60nm B: 60nm or more, less than 80nm C: 80nm or more, less than 100nm In the repeated use of polishing pads for CMP polishing, which requires precision, S is the best, A is preferably used, B is for general use, and C cannot be used.

[0101] [Table 1]

[0102] The present application also discloses the following methods for producing an adhesive sheet for fixing a polishing pad, items

[10] to

[12] .

[10] 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 process of applying adhesive a to the surface of a release sheet FA having a regular and fixed shape in plan view of the recesses on the surface and an average height Rc of the release-treated surface recesses of 5 to 25 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 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 under the following condition 1 is 0.1 to 30 seconds, The surface smoothness determined by the following condition 2 is 1 to 500 seconds. A method for manufacturing an adhesive sheet for fixing a polishing pad with release sheet FA and 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.

[0103]

[11] 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 process of overlaying the surface of the adhesive layer A that is not in contact with the sheet-like substrate with the surface of a release sheet FA, the surface of which has a regular and fixed shape in plan view and an average height Rc of the unevenness of the release-treated surface of 5 to 25 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 under the following condition 1 is 0.1 to 30 seconds, The surface smoothness determined by the following condition 2 is 1 to 500 seconds. A method for manufacturing an adhesive sheet for fixing a polishing pad with release sheet FA and 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.

[0104]

[12] 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 process of applying adhesive a to the surface of a release sheet FA, the surface of which has a regular and fixed shape in plan view and an average height Rc of the release-treated surface irregularities of 5 to 25 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 under the following condition 1 is 0.1 to 30 seconds, The surface smoothness determined by the following condition 2 is 1 to 500 seconds. A method for manufacturing an adhesive sheet for fixing a polishing pad with release sheet FA and 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. [Explanation of symbols]

[0105] 0: Adhesive sheet for fixing polishing pads 1: Adhesive sheet for fixing polishing pads with release sheet FA 2: Adhesive sheet for fixing polishing pads with release sheet FA and release sheet FB 3: Polishing pad with release sheet FA 4: Polishing pad with adhesive sheet for fixing the polishing pad A: Adhesive layer A FA: Release sheet covering the surface of adhesive layer A FA': Pre-release sheet 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 with a release sheet FA, 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, and the surface of the adhesive layer A that is not in contact with the sheet-like substrate is in contact with the release sheet FA, The shape of the convex portions on the outer surface of the release sheet FA in a plan view is regular and fixed, the average height Rc of the irregularities on the outer surface of the release sheet FA is 5 to 25 μm, and the outer surface and the inner surface of the release sheet FA have the same inverted shape, The release sheet FA is made of plastic, The outer surface of the release sheet FA that is not in contact with the adhesive layer A has irregularities, and in a Beck smoothness test, The smoothness of the outer surface of the release sheet FA as determined by the following condition 1 is 0.1 to 30 seconds, The smoothness of the outer surface of the release sheet FA as determined by the following condition 2 is 1 to 500 seconds.

1. An adhesive sheet for fixing a polishing pad with a release sheet FA. 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. An adhesive sheet for fixing a polishing pad with a release sheet FA as described in Claim 1, characterized in that the thickness of the release sheet FA is 25 to 100 μm.

3. An adhesive sheet for fixing a polishing pad with a release sheet FA as described in claim 1, characterized in that the average height Rc of the unevenness on the outer surface of the release sheet FA is 5 to 25 μm, and the average height Rc of the unevenness on the inner surface of the release sheet FA is 5 to 25 μm.

4. 2. The adhesive sheet for fixing a polishing pad with a release sheet FA according to claim 1, wherein the difference in cutting level Rδc of the contour curve of the unevenness on the outer surface of the release sheet FA is 1 to 10 μm.

5. 2. The adhesive sheet for fixing a polishing pad with a release sheet FA according to claim 1, wherein the adhesive layer A is an acrylic adhesive layer.

6. An adhesive sheet for fixing a polishing pad with a release sheet FA described in any one of claims 1 to 3, which is wound into a roll and has a widthwise length of 1000 mm or less.

7. A polishing pad fixing adhesive sheet with a release sheet FA according to any one of claims 1 to 3, and a release sheet FB, the release sheet FB is in contact with the surface of the adhesive layer B that is not in contact with the sheet-like substrate, The adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB, wherein the material of the release sheet FB is plastic.

8. 8. The adhesive sheet for fixing a polishing pad with the release sheets FA and FB according to claim 7, which is wound in a roll shape and has a widthwise length of 1000 mm or less.

9. 8. The adhesive sheet for fixing a polishing pad with the release sheets FA and FB 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 an adhesive sheet for fixing a polishing pad with a release sheet FA according to any one of claims 1 to 5, 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.

11. 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 having the release sheet FA and adhesive layer A described in claim 10 and the adhesive layer A is attached to the surface plate.

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