Adhesive sheet for fixing polishing pad, adhesive sheet for fixing polishing pad with release sheet, polishing pad with adhesive layer A, release sheet and polishing pad with adhesive layer A, method for fixing polishing pad to surface plate, and method for manufacturing adhesive sheet for fixing polishing pad with release sheets FA and FB

Abstract

Provided is an adhesive sheet for fixing a polishing pad for high-precision CMP processing, which is easy to adjust the reattachment position, has excellent air permeability, and also has excellent adhesive physical properties, and is a double-sided adhesive sheet for fixing the polishing pad to a surface plate. 【Solution means】 An adhesive sheet for fixing a polishing pad to a surface plate, comprising an adhesive layer A on one surface of a sheet-shaped base material, and an adhesive layer B on the other surface of the sheet-shaped base material, the surface of the adhesive layer A that is not in contact with the sheet-shaped base material has irregularities, and in the Bekk smoothness test, the smoothness of the said surface calculated | required on the following condition 1 is 1-100 second, the smoothness of the said surface calculated | required on the following condition 2 is 15-1125 second, An adhesive sheet for fixing a polishing pad, characterized by the above. Condition 1: The time until the pressure changes from -50.7 kPa to -48.0 kPa. Condition 2: The time until the pressure changes from -50.7 kPa to -29.3 kPa.

Description

Technical Field

[0001] The present invention relates to an adhesive sheet for fixing a polishing pad to a surface plate. Further, 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. Further, the present invention relates to a polishing pad with an adhesive layer having a specific adhesive layer and a polishing pad. Further, the present invention relates to a polishing pad with a release sheet and an adhesive layer having a release sheet, a specific adhesive layer, and a polishing pad. Further, the present invention relates to a method for fixing a polishing pad to a surface plate via a specific adhesive layer.

Background Art

[0002] In recent years, for the development of semiconductors, higher integration and higher quality have been demanded, and higher polishing accuracy has also been required for wafers as materials. There is a method of polishing by altering only the surface using a chemical reaction such as CMP (Chemical Mechanical Polishing), not only by excavation with simple abrasive grains. In CMP as well, development of techniques for obtaining a smoother polishing surface than before is in progress. When attaching a polishing pad to a surface plate, a double-sided adhesive sheet is used. Specifically, one surface of a double-sided adhesive sheet is attached to one surface of the polishing pad (the side opposite to the surface planned to polish the object to be polished), 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 a polishing pad have been proposed (such as Patent Documents 1 to 3).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

[0005] For polishing pads, various requirements are imposed according to the polishing stage. In particular, the polishing pad used for the final finishing has a multilayer structure with layers having various hardnesses and various thicknesses, and has an increasingly complex structure. The more complex the structure of the polishing pad becomes, the more dramatically the difficulty of the work when attaching the polishing pad to the surface plate increases. When attaching a highly multilayered and thick polishing pad with a single-sided adhesive layer to a surface plate, in many cases, in order to attach it to the target position, repositioning adjustment such as temporary attachment, position confirmation, peeling, and reattachment is required. From the viewpoint of improving productivity, it is desired that the repositioning adjustment be performed in as short a time as possible and with as few times as possible. In terms of ease of repositioning adjustment, the use of an adhesive layer with a small adhesive force is effective. However, for the adhesive layer for fixing the polishing pad to the surface plate, a strong adhesive force and cohesive force (holding force) that can sufficiently withstand polishing are required.

[0006] Further, even if a polishing pad with a single-sided adhesive layer can be quickly temporarily fixed to the target position on the surface plate, when strongly fixing the polishing pad to the surface plate using a roller, a press machine, or the like, there is a problem of air biting where air enters between the surface plate and the adhesive layer. If the air that has entered between the surface plate and the adhesive layer remains locally, the parallelism between the outermost surface of the polishing pad and the surface of the surface plate is impaired, and the polishing target cannot be polished smoothly with high precision, which affects the polishing accuracy. A method of suppressing air biting can be considered by providing grooves serving as air flow paths on the surface of the adhesive layer on the side in contact with the surface plate. However, even if air flow paths are provided, when the polishing pad is strongly fixed to the surface plate, the soft adhesive layer blocks the air flow paths, and the voids cannot be completely removed, or it takes a long time for the air to escape, which reduces the production speed of semiconductors.

[0007] In the adhesive layer of the adhesive sheet that constitutes the double-sided adhesive sheet for fixing the polishing pad to the surface plate, strong adhesive force, cohesive force (holding force) that can withstand the shear force applied during the polishing process, and chemical resistance such as strong alkali resistance and strong acid resistance against the polishing liquid used during polishing are required. In particular, in CMP, since a strongly alkaline polishing liquid is often used, strong alkali resistance is strongly required.

[0008] The present invention has been made in view of the above background, and is an adhesive sheet for fixing a polishing pad for high-precision CMP processing, which is easy to adjust the reattachment position, has excellent air bleeding properties, and also has excellent adhesive physical properties. The purpose is to provide a double-sided adhesive sheet for fixing the polishing pad to the surface plate.

Means for Solving the Problems

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

[14] .

[0010] [1] The present invention is an adhesive sheet for fixing a polishing pad to a surface plate, comprising an adhesive layer A on one surface of a sheet-shaped base material, and an adhesive layer B on the other surface of the sheet-shaped base material. The surface of the adhesive layer A that is not in contact with the sheet-shaped base material has irregularities, and in the Bekk smoothness test, the smoothness of the said surface calculated | required on the following condition 1 is 1 - 100 second, the smoothness of the said surface calculated | required on the following condition 2 is 15 - 1125 second, It is related with the adhesive sheet for polishing pad fixing characterized by the above-mentioned. Condition 1: The time until it changes from -50.7 kPa to -48.0 kPa. Condition 2: The time until it changes from -50.7 kPa to -29.3 kPa.

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

[0012] [6] The present invention is a pressure-sensitive adhesive sheet for fixing a polishing pad with a release sheet FA, comprising the pressure-sensitive adhesive sheet for fixing a polishing pad according to any one of [1] to [5] and a release sheet FA, The release sheet FA is in contact with the pressure-sensitive adhesive layer A, The present invention relates to a pressure-sensitive adhesive sheet for fixing a polishing pad with a release sheet FA, wherein the material of the release sheet FA is a plastic film not containing paper.

[0013] [7] In the present invention, the surface of the pressure-sensitive adhesive layer B that is not in contact with the sheet-like base material is in contact with a release sheet FB, The present invention relates to a pressure-sensitive adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB according to [6], wherein the material of the release sheet FB is a plastic film not containing paper.

[0014] [8] The present invention relates to a roll-shaped pressure-sensitive adhesive sheet for fixing a polishing pad with a release sheet FA according to [6], which is wound in a roll shape and the length in the width direction of the wound body is 1000 mm or less, or a roll-shaped pressure-sensitive adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB according to [7], which is wound in a roll shape and the length in the width direction of the wound body is 1000 mm or less.

[0015] [9] The present invention relates to an adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB, wherein the length of the short side is 1000 mm or less, as described in [7] above.

[0016]

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

[0017]

[11] 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 as described in [6] above, and relates to a polishing pad with a release sheet FA and an adhesive layer A, wherein the polishing pad is in contact with the adhesive layer B.

[0018]

[12] A method for fixing a polishing pad to a surface plate via an adhesive sheet, characterized by peeling the release sheet FA from the polishing pad with the release sheet FA and the adhesive layer A as described in

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

[0019]

[13] A method for manufacturing an adhesive sheet for fixing a polishing pad with a release sheet FA and a release sheet FB, comprising a release sheet FA, an adhesive layer A, a sheet-like substrate, an adhesive layer B, and a release sheet FB, having the following steps (1) to (4): (1) A step of applying an adhesive a to the surface of the release sheet FA whose average height Rc of the unevenness of the peeled surface is 12 to 42 μm to form an adhesive layer A. (2) A step of superposing a sheet-like substrate on the surface of the adhesive layer A that is not in contact with the release sheet FA. (3) A step of applying an adhesive b to the peeled surface of the release sheet FB to form an adhesive layer B. (4) A step of superposing the surface of the adhesive layer B that is not in contact with the release sheet FB on the surface of the sheet-like substrate that is not in contact with the adhesive layer A. The surface that is not in contact with the sheet-like base material of the adhesive layer A has irregularities, and in the Bekk smoothness test, the smoothness of the said surface determined under the following Condition 1 is 1 to 100 seconds, the smoothness of the said surface determined under the following Condition 2 is 15 to 1125 seconds, It relates to a method for manufacturing an adhesive sheet for fixing a polishing pad with release sheets FA and FB. Condition 1: The time until it changes from -50.7 kPa to -48.0 kPa. Condition 2: The time until it changes from -50.7 kPa to -29.3 kPa.

[0020]

[14] A method for manufacturing 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 base material, an adhesive layer B, and a release sheet FB, having the following steps (5) to (8), (5) A step of applying an adhesive a to one surface of the sheet-like base material to form an adhesive layer A. (6) A step of superposing the said surface of the release sheet FA, whose average height Rc of the irregularities of the peeled surface is 12 to 42 μm, on the surface of the adhesive layer A that is not in contact with the sheet-like base material. (7) A step of applying an adhesive b to the peeled surface of the release sheet FB to form an adhesive layer B. (8) A step of superposing the surface of the adhesive layer B that is not in contact with the release sheet FB on the surface of the sheet-like base material that is not in contact with the adhesive layer A. The surface that is not in contact with the sheet-like base material of the adhesive layer A has irregularities, and in the Bekk smoothness test, the smoothness of the said surface determined under the following Condition 1 is 1 to 100 seconds, the smoothness of the said surface determined under the following Condition 2 is 15 to 1125 seconds, It relates to a method for manufacturing an adhesive sheet for fixing a polishing pad with release sheets FA and FB. Condition 1: The time until it changes from -50.7 kPa to -48.0 kPa. Condition 2: The time until it changes from -50.7 kPa to -29.3 kPa.

[0021]

[15] A method for manufacturing 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 base material, an adhesive layer B, and a release sheet FB, and having the following steps (9) to (12): (9) A step of applying an adhesive b to the peeled surface of the release sheet FB to form an adhesive layer B. (10) A step of overlapping a sheet-like base material on the surface of the adhesive layer B that is not in contact with the release sheet FB. (11) A step of applying an adhesive a to the surface of the release sheet FA having an average height Rc of unevenness on the peeled surface of 12 to 42 μm to form an adhesive layer A. (12) A step of overlapping the surface of the adhesive layer A that is not in contact with the release sheet FA on the surface of the sheet-like base material 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 base material has irregularities, and in the Bekk smoothness test,[[]] the smoothness of the said surface calculated|required on the following condition 1 is 1 to 100 seconds,[[]] the smoothness of the said surface calculated|required on the following condition 2 is 15 to 1125 seconds,[[]] Relates to a method for manufacturing an adhesive sheet for fixing a polishing pad with release sheets FA and FB. Condition 1: Time until it changes from -50.7 kPa to -48.0 kPa. Condition 2: Time until it changes from -50.7 kPa to -29.3 kPa.

Effect of the Invention

[0022] According to the present invention, it is possible to provide a double-sided adhesive sheet for fixing a polishing pad to a surface plate, which is easy to adjust the reattachment position, has excellent air-bleeding properties, and is also excellent in chemical resistance such as adhesive physical properties, strong alkali resistance, and strong acid resistance. The adhesive sheet for fixing a polishing pad of the present invention can improve the workability during sticking and can significantly improve the polishing accuracy in high-precision CMP processing.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0024] Hereinafter, an example of an embodiment to which the present invention is applied will be described. In this specification, the numerical value “A to B” specified means a value of A or more and B or less.

[0025] <Adhesive sheet for fixing a polishing pad> The adhesive sheet 1 for fixing a polishing pad of the present invention (hereinafter also simply referred to as an adhesive sheet) is provided with an adhesive layer A and an adhesive layer B on both surfaces of a sheet-like base material F as shown in Fig. 1-1. In Fig. 1, the unevenness of the surface of the adhesive layer A is not shown. In order to protect the surface of the adhesive layer A (the surface not in contact with the sheet-like substrate F), the surface of the adhesive layer A is covered with the release surface of the release sheet FA, and it is provided as the adhesive sheet 2 for fixing the polishing pad with the release sheet FA. As shown in Fig. 1-2, the surface of the adhesive layer B (the surface not in contact with the sheet-like substrate F) of the adhesive sheet 2 for fixing the polishing pad with the release sheet FA is covered with the release sheet FB, and as shown in Fig. 1-3, there is a form without the release sheet FB covering the surface of the adhesive layer B. In the form of Fig. 1-3, as shown in Fig. 1-3', the adhesive sheet 2 for fixing the polishing pad with the release sheet FA is wound around a cylindrical member called a core (also referred to as a core material), and the surface of the adhesive layer B is covered with the other surface of the release sheet FA (the surface not in contact with the adhesive layer A). In the adhesive layer B in the adhesive sheet 2 for fixing the polishing pad with the release sheet FA, as shown in Fig. 1-4, the polishing pad PP is laminated in advance, and the polishing pad 4 with the release sheet FA and the adhesive layer A is formed. Next, the release sheet FA is peeled off, the adhesive layer A is exposed, and the polishing pad 3 with the adhesive layer A is attached to the surface plate SP. The adhesive layer A in the adhesive sheet 1 for fixing the polishing pad is in contact with the surface plate, and the adhesive layer B is in contact with the polishing pad. That is, the polishing pad PP is fixed to the surface plate SP through the adhesive sheet 1 having a laminated structure of the adhesive layer A / the sheet-like substrate F / the adhesive layer B.

[0026] When attaching the polishing pad PP to the surface plate through the adhesive sheet 1, in many cases, until now, the surface of the polishing pad PP has been squeezed with a roll or a squeegee etc. slowly from the end while slightly warping and bending the polishing pad PP, and it has been attached while pushing out the air from the end. When attaching the adhesive layer A to the surface plate, if the adhesive sheet is distorted or an uneven force is applied to the adhesive sheet, a large local air pocket is generated between the surface plate SP and the adhesive layer A. By the way, recently, the polishing pad PP tends to increase in thickness, become extremely hardened, or become extremely softened. The polishing pad PP with an increased thickness or extremely hardened is too rigid to be bent as in the past, and a squeezing roll or squeegee etc. cannot sufficiently act on the surface of the polishing pad PP. On the one hand, since the extremely softened polishing pad PP is easily bent and deformed, it is difficult to maintain a bent state when squeezing the surface of the polishing pad with a roll or squeegee. In any case, it is impossible to quickly extrude the air at the sticking interface or level it across the entire interface, and large local air pockets are likely to remain. Also, when squeezing the surface of the polishing pad PP with a roll or squeegee, local pressure is applied to the surface of the polishing pad PP. Although the pressure is sequentially applied to the entire surface of the polishing pad, since the surface of the polishing pad PP is the surface planned to be in contact with the object to be polished (workpiece), there is also a requirement not to apply too much force.

[0027] The surface of the adhesive layer A in the adhesive sheet of the present invention (the surface planned to be in contact with the surface plate SP) has unevenness specified by the Bekk smoothness test. By using the concave portions on the surface of the adhesive layer A as ventilation paths (flow paths), the air between the surface plate SP and the adhesive layer A can be extruded from the surroundings to the outside or leveled across the entire sticking interface. As a result, it is possible to suppress and prevent the generation of large local air pockets between the surface plate and the adhesive sheet that would impair the parallelism between the surface of the polishing pad (the surface in contact with the object to be polished) and the surface plate.

[0028] The Bekk smoothness of the surface of the adhesive layer A will be described. The Bekk smoothness is defined in JIS P8119. An outline of the procedure of the Bekk smoothness test will be described. (1) Place the test piece on the plane of a glass (a ring-shaped glass member having a circular hole connected to a vacuum chamber in the center) with an optically flat finish. (2) While applying a pressure of 0.1 MPa to the rubber pressing plate placed on the test piece through the pressure plate, reduce the pressure in the vacuum chamber to -50.7 kPa. When the pressure reaches -50.7 kPa, stop reducing the pressure and suck in atmospheric air between the glass plane and the contact surface of the test piece. Measure the time it takes for the pressure in the vacuum container to change from -50.7 kPa to -48.0 kPa under Condition 1, and the time it takes to change from -50.7 kPa to -29.3 kPa under Condition 2. The ease of ventilation on the surface of the adhesive layer A can be evaluated based on these values. That is, in both cases of Condition 1 and Condition 2, the shorter the time it takes to return to the predetermined pressure, the easier it is to ventilate.

[0029] In the case of the present invention, as shown in Fig. 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, then cut into a 50 mm square, stacked in four layers, and circular holes with a radius of 5 mm (smaller than the circular hole in the center of the glass member) are opened to obtain a measurement sample. As shown in Fig. 2(b), place the bottom adhesive layer A surface on the surface of the glass member so that the hole in the measurement sample is directly above the circular hole in the center of the glass member, place a rubber pressing plate on the upper surface of the top PET film, and apply a pressure of 0.1 MPa through the pressure plate. Then, suck and reduce the pressure from the lower part of the circular hole in the center of the glass member to obtain the smoothness under Condition 1 and Condition 2. Since the measurement sample stacks four adhesive sheets, 1 / 4 of the measured value is the result of the adhesive layer A per adhesive sheet. That is, if the measured value is 4 seconds, the Beck smoothness of the adhesive layer A is 1 second. For ease of handling during measurement, after depositing metals such as platinum, palladium, and gold on the surface of the adhesive layer A to remove the adhesive performance, it is also possible to stack them in four layers.

[0030] It is important that the Beck smoothness of the surface of the adhesive layer A is 1 to 100 seconds under Condition 1, more preferably 2 to 50 seconds, particularly preferably 6 to 35 seconds, and most preferably 15 to 30 seconds. The smoothness of Condition 1 is related to the movement and state of air at the very initial stage when the adhesive layer A contacts the surface plate, and is mainly related to position adjustment. That is, when the smoothness of Condition 1 is 100 seconds or less, when the adhesive layer A is brought into contact with the surface plate, it is difficult for a large local air pocket to occur, and the adhesive layer A can be closely adhered to the surface plate so as to be adsorbed. When the position of the adhesive layer A in contact with the surface plate is appropriate and no position adjustment is required, if the smoothness of Condition 1 is less than 1 second, the air permeability is too good, and the position of the adhesive layer A is more likely to shift instead. That is, when the smoothness of Condition 1 is 1 second or more, it becomes easier to appropriately maintain the position of the polishing sheet adsorbed on the surface plate.

[0031] Also, the Bekk smoothness of the surface of the adhesive layer A is importantly 15 - 1125 seconds under Condition 2, preferably 20 - 500 seconds, more preferably 60 - 375 seconds, and most preferably 80 - 300 seconds. The smoothness of Condition 2 is related to the movement and state of air during the period of several minutes to about ten-odd minutes after the adhesive layer A is attached to the surface plate, and is mainly related to the air bleeding property of the attachment interface. When the smoothness of Condition 2 is 1125 seconds or less, even if a local air pocket occurs between the surface plate and the adhesive layer A, it becomes easier to even out the air throughout the attachment interface or exhaust the air from the outer periphery through the concave portions of the attachment interface. When the smoothness of Condition 2 is 15 seconds or more, the adhesive layer A in contact with the surface plate adheres more firmly to the surface plate.

[0032] Note that the surface of the adhesive layer B (the surface intended to contact the polishing pad) does not necessarily need to have special irregularities. When attaching the polishing pad 3 with the adhesive layer A to the surface plate SP, since it is attached by hand, a large local air pocket is likely to occur between the adhesive layer A and the surface plate SP. On the other hand, when attaching the polishing pad PP to the adhesive layer B of the adhesive sheet 2 for fixing the polishing pad with the release sheet FA, since it is attached mechanically rather than by hand, different from the case of attaching the polishing pad 3 to the surface plate SP, a large local air pocket is unlikely to occur in the first place.

[0033] The shape of the irregularities (cross-section) on the surface of the adhesive layer A will be described. From the viewpoint of improving alignment accuracy, it is preferable that the vicinity of the top of the convex portion has a gentle roundness as shown in Fig. 3-1 rather than being flat as shown in Fig. 3-2. Also, from the viewpoint of improving air venting property, Fig. 3-1 with a wider concave portion of the adhesive layer A is more preferable than Fig. 3-2. Fig. 3-3 has a wider concave portion of the adhesive layer A than Fig. 3-2, so some improvement in air venting property can be expected in that regard. However, since the concave portion of the adhesive layer A becomes wider, there is a possibility that the polishing accuracy may decrease.

[0034] Therefore, in order to improve alignment accuracy and air venting property without reducing polishing accuracy, the average height Rc (hereinafter abbreviated as average height Rc) of the roughness curve elements on the surface of the adhesive layer A is preferably 10 to 40 μm, more preferably 15 to 35 μm, and even more preferably 20 to 30 μm. Since the relative depth of the concave portion becomes deeper when the average height Rc is 10 μm or more, the air permeability is improved in both conditions 1 and 2 of the Beck smoothness test, and the alignment accuracy and air venting property are improved. In particular, the influence on the air venting property is large, and after polishing is completed, it becomes easier to peel the polishing pad from the surface plate together with the adhesive sheet. When the average height Rc is 40 μm or less, the polishing accuracy on the surface plate is improved.

[0035] The shape of the unevenness on the surface of the adhesive layer A of the present invention can more specifically grasp the shape of the unevenness such as the roundness, inclination of the convex portion, and the interval of the unevenness from two parameters of the cutting level difference of the contour curve: Rδc and kurtosis: Rku. For Rδc, 5 to 25 μm is preferable, 10 to 20 μm is more preferable, and 12.5 to 19.0 μm is even more preferable. Rδc is the difference in the height direction of the levels that coincide with any two load length ratios from the load curve (a curve obtained by plotting the ratio of the actual body length to the measurement length in the order of height). In the present invention, the two load length ratios are defined as 0% and 50%. When Rδc is 5 μm or more, it is difficult to generate an air pocket at the very initial stage of pasting, and the top of the convex portion of the adhesive layer A contacts the surface plate loosely (lightly). In other words, since the adhesive layer does not adhere to the surface plate very firmly, when peeling the adhesive layer A from the surface plate once contacted, it can be peeled with a small resistance, and it becomes easy to adjust the position. Incidentally, since the adhesive layer A is adhesive, it is considered that it will be deformed to some extent when the adhesive layer A is attached to the surface plate. That is, it is microscopically imagined that when attaching, the convex portions on the surface of the adhesive layer A are slightly crushed, and relatively, the concave portions become slightly shallower. When Rδc is 25 μm or less, when the adhesive layer A is strongly attached to the surface plate, the adhesive layer A is less likely to be crushed, the depth of the concave portion is maintained, and the air bleeding property is improved.

[0036] Also, it is preferable that the kurtosis: Rku of the surface of the adhesive layer A is less than 3. That Rku is less than 3 indicates a rounded convex shape. By bringing the rounded top of the convex portion into contact with the surface plate during attachment, the alignment work can be performed with a feeling of adsorption. Particularly when it is in the range of 1.5 or more and less than 3, the workability during alignment is good, and when strongly pressed and fixed, it adheres firmly, so problems such as peeling off during polishing can be suppressed, which is particularly preferable.

[0037] Rc, Rδc, and Rku will be described using schematic diagrams. FIGS. 3-1, 3-4, and 3-5 are cases where Rc is about the same. Assuming that FIG. 3-1 shows the case where Rδc is 5 to 25 μm and Rku is less than 3, in the case of FIG. 3-4 where the slope of the convex portion is steeper than that of FIG. 3-1, Rδc becomes larger than that in the case of FIG. 3-1, and Rku is less than 3. Similarly, for Rδc in FIG. 3-5 where the slope of the convex portion is steeper than that of FIG. 3-1, it becomes larger than that in the case of FIG. 3-1, and since the top of the convex portion is pointed, Rku becomes larger than 3. Also, FIGS. 3-6 and 3-7 also imagine the case where Rc is about the same as that in FIG. 3-1. However, since the uneven interval is wider than that in the case of FIG. 3-1, Rδc becomes smaller than that in the case of FIG. 3-1. In the case of FIG. 3-6, Rku becomes smaller than 3, and in the case of FIG. 3-7, Rku becomes larger than 3.

[0038] Rc, Rδc, and Rku are values measured based on JIS B 0601 (2013). Specifically, they can be measured using a digital microscope (VHX-7000 manufactured by Keyence Corporation). Specifically, at a magnification of 400 times, five consecutive images are taken vertically and horizontally for a field of view of approximately 460 μm in length and approximately 640 μm in width (a total of 25 images), and a region of approximately 2300 μm in length and approximately 3200 μm in width is set as the entire observation field. A region of approximately 1840 μm in length and approximately 2560 μm in width at the center of the entire observation field is set as the measurement field, and Rc, Rδc, and Rku are measured along two diagonals of the measurement field, and the average value of each is obtained. The same applies to the measurement of Rc and the like of the release sheet FA described later.

[0039] Note that the unevenness in the present invention is different from the so-called "mat" unevenness for the purpose of optical dulling. The unevenness on the surface of the adhesive layer A in the present invention is large and rough. An image of the unevenness on the surface of the adhesive layer A in the present invention is shown in Fig. 4-1, and an image of the so-called "mat" unevenness is shown in Fig. 4-2. The fact that Rc, Rδc, and Rku are within the above ranges means that the height difference of the unevenness is larger and the interval of the unevenness is wider than that of the so-called "mat" which is good at general optical dulling, representing an ideal shape for initial position adjustment during pasting, air bleeding during pasting, and fixing the polishing pad parallel and smoothly on the surface plate.

[0040] The unevenness (plan view) of the surface of the adhesive layer A will be described. The unevenness (plan view) of the surface of the adhesive layer A in the present invention may be a regular pattern or pattern such as a lattice pattern or a polka dot pattern, but it is preferably irregular and amorphous as shown below. An example of an image obtained by observing the surface of the adhesive layer A with a laser microscope is shown in Fig. 5. The black portions in the upper figures of Fig. 5-1 and Fig. 5-2 are convex portions, which are irregular and amorphous in plan view. As the irregular and amorphous patterns and designs in the present invention, patterns and designs such as those shown in FIGS. 6(1) to (4) can be exemplified. FIG. 6(1) may also be referred to as a grained, leather-grained, rock-grained, stone-grained, or plain surface. FIG. 6(2) is a kind of uneven pattern and design called mottling in the field of ink and paint. FIG. 6(3) is also called mottling, but it is a pattern and design found in, for example, seals for decorating plastic models. Further, FIG. 6(4) may be referred to as a dalmatian pattern. In the patterns and designs shown in FIGS. 6(1) to (4), neither the convex portions (black portions) nor the concave portions (white portions) have regularity in their positions, and no regularity is recognized in their shapes either.

[0041] If the Bekk smoothness of the surface of the adhesive layer A is within the above range in Conditions 1 and 2, there is no difference in terms of position adjustment and air bleeding when pasting on the surface plate, whether the shape of the unevenness in plan view is irregular and amorphous or regular and definite. However, since the pattern and design in plan view are irregular and amorphous, it is easy to relieve the unevenness of the force during pasting, and it is easy to paste evenly. Also, even if unevenness that does not affect the performance occurs in the adhesive layer A, it is preferable in that it is not easily noticeable when the pattern and design in plan view are irregular and amorphous.

[0042] As a method for obtaining the adhesive layer A having a Bekk smoothness within a predetermined range, a method of using a release sheet FA having unevenness with an average height Rc of 12 to 42 μm on the surface can be mentioned. That is, a release sheet FA' having a release layer is prepared, and then, as shown in FIG. 7-1, it is passed between a metal roll R1 and a rubber roll R2 that have been processed into a desired surface shape at a high temperature, thereby reversely transferring the surface shape of the metal roll R1 to produce a release sheet FA having unevenness with an average height Rc of 12 to 42 μm. When the surface shape of the release sheet FA is reversely transferred by the rotation of the metal roll R1, its surface shape will have a certain periodicity, but this periodicity is different from the meaning of the regularity in plan view described above.

[0043] And (1) Apply the adhesive a on the release layer of the release sheet FA, and dry it if necessary to form the adhesive layer A. (2) Stack the sheet-like substrate on the surface of the adhesive layer A that is not in contact with the release sheet FA. (3) Apply the adhesive b on the surface of the release sheet FB that has been release-treated, and dry it if necessary to form the adhesive layer B. (4) Stack the surface of the adhesive layer B that is not in contact with the release sheet FB on the surface of the sheet-like substrate that is not in contact with the adhesive layer A. As a result, an adhesive sheet for fixing a polishing pad with a release film having a laminated structure of [release sheet FA / adhesive layer A / sheet-like substrate F / adhesive layer B / release sheet FB] as shown in FIG. 7-2 can be produced.

[0044] Or, (5) Apply the adhesive a on one surface of the sheet-like substrate, and dry it if necessary to form the adhesive layer A. (6) Stack the surface of the release sheet FA having an average height Rc of the unevenness of the release-treated surface of 12 to 42 μm on the surface of the adhesive layer A that is not in contact with the sheet-like substrate. (7) Apply the adhesive b on the surface of the release sheet FB that has been release-treated, and dry it if necessary to form the adhesive layer B. (8) Stack the surface of the adhesive layer B that is not in contact with the release sheet FB on the surface of the sheet-like substrate that is not in contact with the adhesive layer A. Even by such a method, an adhesive sheet for fixing a polishing pad with a release film having a laminated structure of [release sheet FA / adhesive layer A / sheet-like substrate F / adhesive layer B / release sheet FB] as shown in FIG. 7-2 can be produced.

[0045] Or, (9) Apply the adhesive b on the surface of the release sheet FB that has been release-treated, and dry it if necessary to form the adhesive layer B. (10) Stack the sheet-like substrate on the surface of the adhesive layer B that is not in contact with the release sheet FB. On the surface of the release sheet FA with the average height Rc of the unevenness of the peeled surface being 12 to 42 μm, an adhesive a is applied and dried as necessary to form an adhesive layer A. (12) The surface of the sheet-like base material that is not in contact with the adhesive layer B is overlapped with the surface of the adhesive layer A that is not in contact with the release sheet FA. Even with such a 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 base material F / adhesive layer B / release sheet FB] as shown in Fig. 7-2. In any case, it is preferable that the surface of the adhesive layer B (the surface that is supposed to be in contact with the polishing pad) has no unevenness. Therefore, the release surface of the release sheet FB to which the adhesive b is applied is preferably smooth.

[0046] For the application of the adhesive, known methods such as the roll coater method, comma coater method, lip coater method, die coater method, reverse coater method, silk screen method, gravure coater method, etc. can be used. After application, it can be dried with a hot air oven, infrared heater, etc.

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

[0048] In addition to the above-described transfer method, as a method for forming the pressure-sensitive adhesive layer A having a desired roughness, an adhesive can be further ejected onto the surface of the pressure-sensitive adhesive layer having a smooth surface by inkjet to create a pattern having a desired surface shape, and then dried and cured to form the layer. Alternatively, it can also be obtained by pressing a metal plate having a desired roughness against a smooth pressure-sensitive adhesive layer at a high temperature. Alternatively, it can also be obtained by partially burning off a part of the pressure-sensitive adhesive layer on the surface of the smooth pressure-sensitive adhesive layer by laser processing. Among the above, the method of forming the pressure-sensitive adhesive layer on the release film having desired irregularities and transferring the irregularities of the release film to the pressure-sensitive adhesive layer to obtain the pressure-sensitive adhesive layer A is preferable because the manufacturing quality is stable and the manufacturing speed is fast.

[0049] <Pressure-sensitive adhesive layer> The pressure-sensitive adhesive layer A and the pressure-sensitive adhesive layer B in the pressure-sensitive adhesive sheet for fixing the polishing pad of the present invention are respectively located on the outermost surfaces of the pressure-sensitive adhesive sheet. The sheet-like base material may be a single layer or a laminate of various members, and the number of laminations is not particularly limited. The thickness of the pressure-sensitive adhesive layer A of the pressure-sensitive adhesive sheet for fixing the polishing pad is preferably 15 to 100 μm, more preferably 30 to 70 μm. By setting the thickness of the pressure-sensitive adhesive layer A to 15 μm or more, the adhesive force is easily developed, and by setting it to 100 μm or less, the required uneven shape of the present invention is easily formed. By being in a more preferable range, the adhesiveness is excellent, and when the pressure-sensitive adhesive sheet becomes hot during polishing, the problem that the pressure-sensitive adhesive layer is displaced in the shear direction is suppressed. The thickness is the average value measured at five arbitrary points with a Φ7.5 mm measuring head under a pressing force of 0.01 N using a thickness gauge Mitutoyo Lite-Matic VL-50B. The thickness of the pressure-sensitive adhesive layer B is not particularly limited as long as various polishing pads can be fixed, but by making it 200 μm or less in combination with the thickness of the pressure-sensitive adhesive layer A excluding the thickness of the base material layer, the proportion of the pressure-sensitive adhesive layer, which is a low elastic body, in the entire pressure-sensitive adhesive sheet decreases, and the polishing accuracy is improved.

[0050] In the adhesive layers A and B of the adhesive sheet of the present invention, acrylic adhesives, elastomer adhesives, urethane adhesives, silicone adhesives, etc. can be used, and two or more kinds can be used in combination. From the viewpoints of less generation of gel, less likely to generate local elastic modulus differences, and easy control of adhesive force, acrylic adhesives are preferred. While metal catalysts are often used during the synthesis of elastomer adhesives and urethane adhesives, and metal catalysts are often used during the curing of silicone adhesives, acrylic adhesives are preferred from the viewpoint that they have a low metal catalyst content, are less likely to affect CMP processing, and have high chemical resistance. In addition, in order to cope with a rich variety of polishing pad materials, it is preferable to select an acrylic adhesive with a rich variety of monomer species for the adhesive layer B.

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

[0052] <(Meth)acrylate Resin> The (meth)acrylate resin is obtained by copolymerizing a monomer having a hydroxyl group and another monomer not having a hydroxyl group. That is, the (meth)acrylate resin is a copolymer composed of units derived from a monomer having a hydroxyl group and units derived from other monomers.

[0053] Examples of the monomer having a hydroxyl group include hydroxyalkyl (meth)acrylate and a compound obtained by adding ε-caprolactone to the hydroxyalkyl (meth)acrylate, and hydroxyalkyl (meth)acrylate is preferred.

[0054] Specific examples of the hydroxyalkyl (meth)acrylate include hydroxyalkyl (meth)acrylates having 1 to 4 carbon atoms in the alkyl group 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 the compound obtained by adding ε-caprolactone to the hydroxyalkyl (meth)acrylate include ε-caprolactone adducts of hydroxyalkyl (meth)acrylates having 1 to 4 carbon atoms such as 1-mole adduct of ε-caprolactone to 2-hydroxyethyl (meth)acrylate, 2-mole adduct of ε-caprolactone to 2-hydroxyethyl (meth)acrylate, and 3-mole adduct of ε-caprolactone to 2-hydroxyethyl (meth)acrylate. However, the present invention is not limited only to such examples. These hydroxyl group-containing monomers may be used alone or in combination. 2-Hydroxyethyl (meth)acrylate is particularly preferable from the viewpoint that the intermolecular distance is relatively close when crosslinked with an isocyanate curing agent and the chemical resistance is improved.

[0055] Examples of other monomers having no hydroxyl group include various monomers as shown below. Examples of the alkyl (meth)acrylate 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, and 2-acetoacetoxyethyl (meth)acrylate and phenoxyethyl (meth)acrylate.

[0056] The weight average molecular weight (Mw) of the acrylic copolymer is preferably from 200,000 to 1,500,000, more preferably from 500,000 to 1,000,000. When the weight average molecular weight (Mw) is 200,000 or more, it is easy to obtain cohesive force that enables the adhesive to withstand strong shear force. When it is 1,500,000 or less, it has excellent heat resistance and is less likely to have reduced adhesion to the abrasive, and the performance is improved in a more preferable range.

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

[0058] <Elastomer-based adhesive> The elastomer-based adhesive contains an elastomer and a tackifier resin. The elastomer preferably includes a styrene-isoprene block copolymer.

[0059] There are styrene-isoprene block copolymers having a linear structure or a radial structure. When having a linear structure, it has a highly flexible structure, so it has excellent adhesion to various adherends and shows more excellent effects on adhesive performance and heat resistance. Therefore, it is preferably a linear structure composed of a triblock of styrene-isoprene-styrene (SIS) or a diblock of styrene-isoprene (SI). The styrene-isoprene block copolymer having a linear structure refers to a linear copolymer in which a block of styrene and a block of isoprene are bonded.

[0060] The styrene content in the styrene-isoprene block copolymer is preferably 20 to 40% by weight in 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, it can have adhesive performance with excellent cohesive force, and the holding power and chemical resistance after being in a high-humidity environment are improved.

[0061] Examples of the styrene-isoprene block copolymer include, but are not limited to, Kraton D1119 (manufactured by Kraton, styrene content 22% by weight, diblock content 66% by weight), Kraton D1126 (manufactured by Kraton, styrene content 21% by weight, diblock content 30% by weight), Kraton D1117 (manufactured by Kraton, styrene content 17% by weight, diblock content 33% by weight), etc. If necessary, two or more of them may be used in combination.

[0062] Also, natural rubber may be contained as long as the required performance is not impaired. The natural rubber is not particularly limited, but it is preferably kneaded with a kneading roll and the Mooney viscosity is, for example, 10 to 100. Other elastomers and natural rubbers are not limited to these and can be used singly or in combination of two or more.

[0063] <Silicone-based adhesive> As the silicone-based adhesive, materials known as silicone resins can be used. Specifically, an organopolysiloxane having silanol groups at both ends of the molecular chain is partially dehydrated and condensed with a triorganosiloxane unit represented by R 3 SiO 0.5 (where R represents a substituted or unsubstituted monovalent hydrocarbon group) and an organopolysiloxane having an SiO 2 unit. These are available as silicone-based adhesives KR-101-10, KR-120, KR-130, X-40-3068 (all manufactured by Shin-Etsu Chemical Co., Ltd.). The curing method of the silicone-based adhesive generally includes a curing method using a peroxide such as benzoyl peroxide and a curing method utilizing the reaction of a platinum catalyst with an organopolysiloxane having an Si—H bond. Either method can be used, and they can also be used in combination.

[0064] <Tackifying resin> Examples of the tackifier resins include rosin-based resins such as rosin esters, polymerized rosins, hydrogenated rosins, disproportionated rosins, maleic acid-modified rosins, fumaric acid-modified rosins, and rosin phenol resins; terpene-based resins such as α-pinene resins, β-pinene resins, dipentene resins, aromatic-modified terpene resins, hydrogenated terpene resins, terpene phenol resins, acid-modified terpene resins, and styrenated terpene resins; alkylphenol resins, coumarone resins, styrene resins, petroleum resins or their copolymers, etc. Among them, terpene phenol resins are particularly preferred. The above-mentioned tackifier resins can be used alone or in combination of two or more. <Hardener>

[0065] A hardener can be added to the adhesive as needed. Since the peel strength when peeling from the surface plate of the polishing machine varies from high adhesive strength to low adhesive strength, it is possible to add a hardener for the purpose of controlling the adhesive strength. As the hardener, isocyanate-based hardeners, aziridine-based hardeners, metal chelate-based hardeners, epoxy-based hardeners, etc. can be used as needed within the range that does not impair the required performance. In particular, for the hardener added to acrylic adhesives, isocyanate-based hardeners are preferred from the viewpoints of cohesion and heat resistance. These hardeners may be used alone or in combination of two or more.

[0066] <Other Additives> The various adhesives for forming the adhesive layer in the adhesive sheet of the present invention may contain various additives such as known antioxidants and other anti-aging agents, fillers, pigments, dyes, diluents, plasticizers, polymerization inhibitors, ultraviolet absorbers, ultraviolet stabilizers, coupling agents, etc. as needed, and two or more of them may be used. Also, the addition amount of the additives may be an amount that can obtain the required physical properties and is not particularly limited.

[0067] <Release Sheet FA>, <Release Sheet FB> The release sheets FA and FB each have a release layer formed by coating a release agent on a sheet-like base material such as paper, a plastic film, or synthetic paper. In CMP processing, a release film using a plastic film with high cleanliness as the sheet-like base material is preferred. As the plastic film for the release sheet FA, a polyethylene terephthalate film that is easy to emboss with a metal roll and is inexpensive is preferred. Further, for the embossing of the release film with the exemplified metal roll, a thickness of 25 to 100 μm is preferred because it is easy to transfer the desired shape formed on the metal surface, and a thickness of 45 μm to 80 μm is even more preferred because it is easier to process. From the point of inverting and transferring the unevenness of the release sheet FA to the surface of the adhesive layer A, the average height Rc of the release sheet FA is preferably 12 to 42 μm, more preferably 17 to 37 μm, and even more preferably 22 to 32 μm. By being in the preferred range, the uneven surface can be inverted and transferred to the adhesive layer A with high accuracy.

[0068] As the plastic film for the release sheet FB, an inexpensive and highly smooth polyethylene terephthalate film is preferred. Although the thickness of the release sheet FB is not particularly limited, a thickness of 10 to 200 μm, which gives the film firmness and makes it easy to peel off, is preferred. Examples of the release agent include silicone-based resins, alkyd-based resins, melamine-based resins, fluorine-based resins, acrylic-based resins, etc., and silicone-based resins are preferred.

[0069] <Sheet-like base material> The sheet-like base material of the present invention is preferably a non-woven fabric and a plastic film. Examples of the plastic film include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate, PPS (polyphenylene sulfide), nylon, triacetyl cellulose, cycloolefin, polyimide, and polyamide formed into films. In particular, a polyethylene terephthalate film with excellent production cost, chemical resistance, and smoothness is preferred.

[0070] The thickness of the sheet-like base material is not particularly limited, but is preferably 5 to 200 μm, more preferably 25 to 75 μm, and particularly preferably 50 to 75 μm. Being in the preferred range ensures that the unevenness of the adhesive layer A does not affect the adhesive layer B or the polishing pad, provides appropriate firmness, and improves workability during pasting. Being in the particularly preferred range further improves workability.

[0071] In the present invention, the sheet-like base material may be subjected to an easy adhesion treatment in order to improve the adhesion between the adhesive layer A and the adhesive layer B. As the easy adhesion treatment, known methods such as a dry method of performing corona discharge and a wet method of coating with an anchor coating agent can be used. When an acrylic adhesive is used for forming the adhesive layer, it is preferable to use a material subjected to an easy adhesion treatment in terms of improving adhesion. On the other hand, in the case of an elastomer adhesive, if an easy adhesion treatment by corona discharge is performed, the adhesive layer is more likely to peel off from the sheet-like base material. Therefore, it is preferable to apply the elastomer adhesive to the surface that has not been subjected to the easy adhesion treatment.

[0072] The thickness of the adhesive sheet for fixing the polishing pad, which is composed of the adhesive layer A, the sheet-like base material, and the adhesive layer B, is preferably 80 to 300 μm, and more preferably 100 to 200 μm. Being 80 μm or more enables uniform processing without force deviation in the lamination process during integration with the polishing pad. Being 300 μm or less enables the adhesive sheet to take a roll shape during production, increasing productivity. Being in the more preferred range ensures that the force of the surface plate is appropriately transmitted to the polishing pad during polishing, improving polishing accuracy.

[0073] <Usage form> An example of the usage form of the adhesive sheet for fixing the polishing pad of the present invention will be described. As shown in FIGS. 1-2 and 7-2, it is also possible to provide an adhesive sheet for fixing a polishing pad with a release sheet FA in a state where each surface of the adhesive sheet for fixing a polishing pad is covered with release sheets FA and FB respectively. Also, as shown in FIG. 1-3, it is possible to provide the adhesive sheet for fixing a polishing pad in a state where only the adhesive layer A side of the adhesive sheet for fixing a polishing pad is covered with the release sheet FA. In the case of the form shown in FIG. 1-3, as shown in FIG. 1-3', a cylindrical member called a core (also referred to as a core material) is wound with an adhesive sheet 2 for fixing a polishing pad with a release sheet FA, and the surface of the adhesive layer B is covered with the other surface of the release sheet FA (the surface not in contact with the adhesive layer A), and it can be provided as a roll-shaped adhesive sheet for fixing a polishing pad with a release sheet FA.

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

[0075] The polishing pad is also referred to as a polishing cloth, a polishing pad, or a polishing PAD, and is a member that contacts the surface of the object to be polished and polishes the object to be polished. The polishing pad includes a single-layer type composed of a single member and a multi-layer type in which a plurality of members are laminated. Examples of the material of the outermost surface of the polishing pad include urethane-based, non-woven fabric-based, suede-based, etc. In the case of the multi-layer type, urethane-based foams, polyethylene-based foams, polypropylene-based foams, etc. are used as cushion materials in the inner layer.

Example

[0076] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples. In the examples, "parts" means "parts by weight" and "%" means "% by weight".

[0077] [Molecular weight] In the following examples, the molecular weight is the weight-average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography). The measuring apparatus was GPC-8020 (manufactured by Tosoh Corporation), the eluent was tetrahydrofuran, three columns of TSKgel Super HM-M (manufactured by Tosoh Corporation) were used, and the measurement was carried out at a column temperature of 40 °C, a flow rate of 0.6 mL / min, a sample concentration of 0.3%, and an injection volume of 10 μL.

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

[0079] (Adhesive) (Production of a solution of acrylic adhesive (P-1)) While introducing nitrogen gas, 500 g of ethyl acetate was heated in a water bath in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer. Subsequently, a mixture of 360 g of BA (n-butyl acrylate), 120 g of 2-EHA (2-ethylhexyl acrylate), 10 g of AA (acrylic acid), 5 g of HEA (hydroxyethyl acrylate), and 0.5 g of AIBN (azobisisobutyronitrile) as an initiator was added dropwise into ethyl acetate, and the reaction was carried out 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 with a weight-average molecular weight (Mw) of 510,000 (non-volatile content 45%). Furthermore, 100 parts of the solution of acrylate resin p-1 and 3 parts of an isocyanate-based curing agent (manufactured by Mitsubishi Chemical Corporation (Mitec GP105A): tolylene diisocyanate, trimethylolpropane adduct) were stirred and mixed, and methyl ethyl ketone was added as a solvent to prepare a solution of acrylic adhesive (P-1) (non-volatile content 45%).

[0080] (Production of a solution of acrylic adhesive (P-2)) Into a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, 500 g of ethyl acetate was heated in a water bath while introducing nitrogen gas. 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 into ethyl acetate, and the reaction was carried out 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 with a weight average molecular weight (Mw) of 800,000 (non-volatile content: 45%). Furthermore, 100 parts of the solution of acrylate resin p-2 and 3 parts of an isocyanate-based curing agent (manufactured by Mitsubishi Chemical Corporation (Mitec GP105A): tolylene diisocyanate, trimethylolpropane adduct) were stirred and mixed, and methyl ethyl ketone was added as a solvent to prepare a solution of acrylic pressure-sensitive adhesive (P-2) (non-volatile content: 45%).

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

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

[0083] Release sheet <fa-1>Manufacture The PET release film "RF2PETCS001-50" (thickness: 50 μm, one-sided silicone release treatment, Rc: 0.2 μm) manufactured by I'm Co., Ltd. with a size of approximately 30 cm × 30 cm was passed between a metal roll with a PG7 pattern (mat pattern) owned by the United Resin Industry Co., Ltd. and a rubber roll under the conditions of temperature: 220 °C, pressure: 5 MPa, and speed: 3 m / min to obtain a release sheet FA-1 with the mat pattern transferred. Using a digital microscope (VHX-7000 manufactured by Keyence Corporation), the Rc measured by the above method was 6.1 μm. The thickness of the PET release film is the average value measured at five arbitrary points with a pressing force of 0.01 N using a thickness gauge Lite-Matic VL-50B (manufactured by Mitutoyo Corporation) with a measuring head of Φ7.5 mm.

[0084] Release Sheet <fa-2> ~ <fa-6>Manufacture Except for using metal rolls with PG16, PG12, PG14, PG18, and PG68 handles owned by the Joint Resin Industry Social Insurance instead of the metal roll with a PG7 handle owned by the same social insurance, under the same processing conditions as in the case of the release sheet FA-1, release sheets FA-2 to FA-7 with a matte pattern were obtained.

[0085] Release Sheet <fa-7> ~ <fa-10>Manufacture After obtaining the release sheets FA-3, FA-4, FA-5, and FA-6, each release sheet was passed between a metal roll with a smooth surface and a rubber roll under the conditions of a temperature of 110°C, a pressure of 3.0 MPa, and a speed of 0.5 m / min to obtain the release sheets FA-7, FA-8, FA-9, and FA-10.

[0086] Release sheet <fa-11>Manufacture Instead of the metal roll with a PG7 handle owned by the Joint Resin Industry Co., Ltd., a metal roll with a lattice pattern (lattice pattern with a line width of 200 μm, a line height of 26 μm, and 1400 μm × 1400 μm) owned by the same company was used. Under the same processing conditions as in the case of the release sheet FA-1, that is, "RF2PETCS001-50" was passed between the metal roll and the rubber roll at a temperature of 220 °C, a pressure of 5 Mpa, and a speed of 3 minutes / m to obtain a release sheet FA-11 with a lattice pattern.

[0087] Release sheet <fa-12>Manufacture Instead of the metal roll with a PG7 handle owned by the United Resin Industry Co., Ltd., a matte pattern release sheet FA-12 was obtained under the same processing conditions as those for the release sheet FA-1, except that a metal roll with a PG27 handle owned by the same company was used.

[0088] Release sheet <fa-13>Manufacture Instead of the metal roll with a PG7 pattern owned by the United Resin Industry Co., Ltd., "RF2PETCS001-50" was passed between a metal roll with a lattice pattern (lattice pattern with a line width of 200 μm, a line height of 26 μm, and a size of 1400 μm × 1400 μm) owned by the same company and a rubber roll under the conditions of a temperature of 200°C, a pressure of 1.0 MPa, and a speed of 15 m / min to obtain a release sheet FA-13 with the above-mentioned grained pattern transferred.

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

[0090] <Release sheet FB> · FB-1 RF2PETCS001-50, manufactured by Aime Co., Ltd., PET release film (thickness: 50 μm, single-sided silicone release treatment, Rc: 0.2 μm)

[0091] <Other release sheets> ·Apply 0.1 g / m of BYK's silicone treatment agent "BYK300" to a FH-21 matte gray polyester film (Unitika, Emblet "PTH-38") with a coil bar. 2 The film thus obtained was used as a release surface. Rc: 1.5 μm

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

[0093] <Example 1> Production of an adhesive sheet for fixing a polishing pad and an adhesive sheet for fixing a polishing pad with a release sheet On the release surface of the release sheet FA-1, a solution of the adhesive P-1 was applied with a doctor blade so as to be 50 μm after drying, and dried in an oven at 80 °C to form an adhesive layer A-1. A sheet-like substrate F-1 was bonded to the surface of the adhesive layer A-1 with a hand roller. Separately, a solution of the adhesive P-2 was applied to the release surface of the release sheet FB-1 with a doctor blade so as to be 50 μm after drying, and dried in an oven at 80 °C to form an adhesive layer B-1. Next, by bonding the opposite surface of the adhesive layer B-1 to the release sheet FB-1 to the opposite surface of the adhesive layer A-1 via the sheet-like substrate F-1 with a hand roller, a polishing pad fixing adhesive sheet having a laminated structure of [adhesive layer A-1 / sheet-like substrate F-1 / adhesive layer B-1] was obtained, with a release sheet FA-1 attached to the adhesive layer A-1 and a release sheet FB-1 attached to the adhesive layer B-1. According to the method described later, the properties of the obtained adhesive sheet (beck smoothness of the surface of the exposed adhesive layer A-1, average roughness Rc, cut-off level difference Rδc of the contour curve, kurtosis Rku) were determined according to the method described later. Also, according to the method described later, the performance of the obtained adhesive sheet (adhesion workability, air bleeding property, adhesive strength, alkali resistance, holding power, polishing accuracy) was evaluated.

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

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

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

[0097] [Properties of the Pressure-Sensitive Adhesive Sheet] <Bekk smoothness> The release sheet FB that covered the adhesive layer B was peeled off from the pressure-sensitive adhesive sheet for fixing a polishing pad with a release sheet prepared in the Examples and Comparative Examples, the exposed adhesive layer B was bonded to a 100-μm PET film (Rc: 0.2 μm), and the bonded material was cut into a size of 50 mm square. Next, the release sheet FA that covered the adhesive layer A was peeled off to expose the adhesive layer A, and a vapor deposition film with a thickness of about 20 nm was formed on the surface of the adhesive layer A using "MSP15" of Vacuum Device Co., Ltd. with a target of Pt-Pd and an operating time of 1 minute to eliminate tack. Four samples with eliminated tack were stacked, and a circular hole with a radius of 5 mm was punched in the center in a Thomson type to form a measurement sample. Place the measurement sample on the glass plate of the Bekk smoothness meter (manufactured by Kumagai Riki Kogyo Co., Ltd.) such that the adhesive layer A side of the measurement sample is in contact with the glass plate and the hole in the measurement sample is positioned directly above the central circular hole on the glass plate. Place a rubber pressing plate on the upper surface of the topmost PET film of the measurement sample, and while applying a pressure of 0.1 MPa via a pressure plate, suck from below the central circular hole of the glass member and reduce the pressure to -50.7 kPa. When -50.7 kPa is reached, stop reducing the pressure, and measure five times each the time from -50.7 kPa to when it changes to -48.0 kPa (Condition 1) and the time from -50.7 kPa to when it changes to -29.3 kPa (Condition 2), obtain the average value, and further divide by 4, which is the number of sheets stacked. Also, if any one of the five measurements exceeds 2000 seconds, discontinue the measurement and record ">2000" in the table.

[0098] <Rc, Rδc, Rku> Measured using a digital microscope (VHX-7000 manufactured by Keyence Corporation) based on JIS B 0601 (2013).

[0099] [Evaluation of Adhesive Sheet] <Affixation Workability (Position Adjustment)> Explain the procedure along with Figure 8. As shown in Figure 8-1, cut the abrasive pad fixing adhesive sheet with a release sheet prepared in the examples and comparative examples into a size of 210 mm square, peel off the release sheet FB to expose the adhesive layer B, and laminate it on a smooth glass plate (about 300 g) with a thickness of 3 mm and a size of 200 mm square in an atmosphere of 23°C - 50% RH. Remove the adhesive sheet protruding from the four sides of the glass plate with a cutter to obtain a sample for evaluating the affixation workability having a structure of [glass / adhesive sheet / release sheet FA] with a size of 200 mm square (hereinafter referred to as the sample). Note that in Figure 8, the laminated state of the adhesive sheet and the laminated state of the adhesive sheet and the release sheet FA are omitted. As shown in Figure 8-2, draw two types of frame lines with thicknesses of 1 mm, one with a size of 200 mm square and the other with a size of 150 mm square, in approximately the center of one surface of a 300 mm square glass plate using an oil-based magic marker to obtain the evaluation adherend (hereinafter referred to as the adherend). As shown in Fig. 8-3, peel off the release sheet FA of the sample to expose the adhesive layer A, and place it so that two sides of the 200 mm square sample protrude at least 10 mm each from two sides of the 200 mm square outer frame written on the adherend. The placement surface shall be the surface opposite to the surface on which the two types of frames are written. Immediately after placement, peel the sample from the adherend, adjust the position to match the 200 mm square frame line of the adherend as shown in Fig. 8-4, and measure the time from placement to peeling and re-pasting (placement ~ peeling ~ re-pasting). Five arbitrarily selected persons performed the operation, scored as follows respectively, and further evaluated the pasting workability from the total score of the five persons. The scores for the pasting workability were given as follows. 3 points: The alignment with the frame line could be easily achieved within 10 seconds. 2 points: The alignment could be achieved in more than 10 seconds and less than 15 seconds. 1 point: The alignment could be achieved in more than 15 seconds and less than 30 seconds. 0 point: It exceeded 30 seconds. The evaluation criteria for the pasting workability are as follows. S: 13 - 15 points A: 10 - 12 points B: 7 - 9 points C: 4 - 6 points D: 0 - 3 points

[0100] <Evaluation of air bleeding property> As shown in Fig. 9-1, immediately after the evaluation of the laminating workability was completed, place a 500 g weight for an upper pan balance with a diameter of 41 mm and a height of 63 mm on the center of the five evaluation samples and let it stand for 180 seconds. Then, as shown in Fig. 9-2, excluding the weight, based on the number of air pockets with a diameter of 5 mm or more inside the 150 mm square frame line and the presence or absence of air pockets with a diameter of 10 mm or more on the adherend side (the back surface of the 300 mm square glass plate), score as follows. Further evaluate the air bleeding property from the total score of the five samples. The score criteria for the air bleeding property were given as follows. 3 points: There are 0 air pockets with a diameter of 5 mm or more inside the frame. 2 points: There are 1 - 2 air pockets with a diameter of 5 mm or more inside 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 inside the frame, and there are no air pockets with a diameter of 10 mm or more. 0 point: There are more than 5 air pockets with a diameter of 5 mm or more inside the frame, and there are air pockets with a diameter of 10 mm or more. The evaluation criteria for air bleeding are as follows. S: 13 - 15 points A: 10 - 12 points B: 7 - 9 points C: 4 - 6 points D: 0 - 3 points

[0101] [Preparation of Adhesive Sample for Measuring Adhesion Performance] <Evaluation of Initial Adhesive Force of Adhesive Layer A> In an atmosphere of 23°C - 50% RH, the release sheet FB was peeled off from the adhesive sheet for fixing the polishing pad with a release sheet. The exposed adhesive layer B was bonded to a 25 - μm PET film, cut into a size of 25 mm in width × 100 mm in length, and used as a sample for evaluating the adhesive force. Then, the release sheet FA was peeled off, the exposed adhesive layer A was overlapped on a stainless - steel plate, and a 2 - kg roller was reciprocated once to crimp the adhesive layer A onto the stainless - steel plate. After leaving it for 24 hours, the adhesive force of the adhesive layer A (adhesive force to SUS) was measured in an atmosphere of 23°C - 50% RH using a tensile testing machine under the conditions of a peeling angle of 180 degrees and a peeling speed of 0.3 m / min in accordance with the measurement method of JIS Z1528. The obtained measured values are shown in Table 1.

[0102] <Evaluation of Chemical Resistance> The release sheet FA was peeled off from the sample for evaluating the adhesive force, the exposed adhesive layer A was overlapped on a stainless - steel plate, and a 2 - kg roller was reciprocated once to crimp the adhesive layer A onto the stainless - steel plate. Then, within 30 minutes, it was immersed in an aqueous sodium hydroxide solution with a pH of 11.5 while still attached to the stainless - steel plate and left in an environment of 40°C for 24 hours. After that, the sample was taken out from the aqueous sodium hydroxide solution, washed with water, and left in an atmosphere of 23°C - 50% RH for 1 hour. The adhesive force was measured in the same method as the above <Measurement of Initial Adhesive Force> to obtain the <Adhesive Force after Immersion>, and the difference between the initial adhesive force and the adhesive force after immersion was calculated. The smaller this difference is, the better the chemical resistance. The evaluation criteria for chemical resistance are as follows. A: The difference in adhesion is 1.5 N / 25 mm or less, extremely good B: The difference in adhesion is more than 1.5 N / 25 mm and less than 2.0 N / 25 mm, good C: The difference in adhesion is 2.0 N / 25 mm or more and less than 3.0 N / 25 mm, practical D: The difference in adhesion is 3.0 N / 25 mm or more, not usable In CMP processing where various chemical solutions are used according to the object to be polished, strong chemical resistance is required. S is the best, A is preferably used, B is generally used, C has limited applications, and D cannot be used.

[0103] <Evaluation of holding power> Peel off the release sheet FA from the sample for adhesion evaluation. Among the exposed adhesive layers A, only the range with a width of 25 mm × a length of 25 mm is overlapped on the stainless steel plate, and a 2 kg roller is reciprocated once. After pressing the adhesive layer A onto the stainless steel plate, it is left in an atmosphere of 23°C - 50% RH for 20 minutes. Then, a 1 kg weight is attached to the end of the sample not attached to the stainless steel plate in an atmosphere of 80°C and set so that a force is applied in a 180-degree direction. After 24 hours, it is measured how many millimeters the sticking position has shifted. Also, when the sample completely shifts and falls off the adherend, the time until the fall is measured. The evaluation criteria for holding power are as follows. S: The shift is less than 0.1 mm A: 0.1 mm or more and less than 1.0 mm B: The shift is 1.0 mm or more and 5.0 mm or less C: It falls after 180 min or more D: It falls within less than 180 min The smaller the shift, the less likely it is for displacement or peeling to occur during polishing, and the polishing pad can be firmly fixed. Therefore, it can be preferably used in various polishing processes. S is the best, A is preferably used, B is generally used, C has limited applications, and D cannot be used.

[0104] <Polishing accuracy> The release sheet FB was peeled off from the adhesive sheet for fixing the polishing pad with a release sheet, and the non-polishing surface of the polishing pad (CMP cloth manufactured by Musashino Electronics Co., Ltd., Φ200 mm, normal type) was overlapped on the exposed adhesive layer B, and laminated under the conditions of a roll temperature of 80 °C, a pressure of 0.1 MPa, and a speed of 1.0 m / min to produce a polishing pad with an adhesive sheet. MA-200 manufactured by Musashino Electronics Co., Ltd. was used as a polishing device. The release sheet FA was peeled off from the prepared polishing pad with an adhesive sheet, and the exposed adhesive layer A was attached to an aluminum surface plate, and intermediate polishing was carried out under the following conditions. (Conditions) Table rotation speed: 100 rpm Head rotation speed: 105 rpm Polishing target: A test piece obtained by cutting a 200 mm wafer (thickness 75 μm) having a polysilicon layer (500 nm) formed on its surface into a 3 cm square Polishing pressure: 10.0 kPa Polishing time: 15 min Polishing liquid: Colloidal silica abrasive #80 manufactured by Musashino Electronics Co., Ltd. After the polished test piece was washed with water and water droplets were removed with air, the thickness of polysilicon was measured at three arbitrary points, one at the center and two outside the center, using a film thickness measuring instrument FE-300 manufactured by Otsuka Electronics Co., Ltd., and the polishing accuracy was evaluated according to the following criteria based on the difference between the maximum film thickness and the minimum film thickness. S: Less than 10 nm A: 10 nm or more and less than 20 nm B: 20 nm or more and less than 30 nm C: 30 nm or more and less than 50 nm D: 50 nm or more In CMP polishing where accuracy is required, S is the best, A is preferably used, B is generally used, C has limited applications, and D cannot be used.

[0105]

Table 1

Description of Symbols

[0106] 1: Adhesive sheet for fixing polishing pad 2: Adhesive sheet for fixing polishing pad with release sheet 3: Polishing pad with adhesive layer A 4: Polishing pad with release sheet and adhesive layer A A: Adhesive layer A FA: Release sheet covering the surface of adhesive layer A FA’: Precursor of FA B: Adhesive layer B FB: Release sheet covering the surface of adhesive layer B F: Sheet-like base material PP: Polishing pad R1: Metal roll R2: Rubber roll SP: Surface plate E: Rubber pressing plate G: Glass plane H: Pressing plate PET: PET film < / fa-7> < / fa-2>

Claims

1. An adhesive sheet for fixing a polishing pad to a base plate, comprising an adhesive layer A on one side of a sheet-like substrate and an adhesive layer B on the other side of the sheet-like substrate, the surface of the adhesive layer A not in contact with the sheet-like substrate having irregularities, the average height Rc of the surface irregularities being 5.9 to 40 μm, the cut level difference Rδc of the contour curve being 2.5 to 25 μm, and in a Beck smoothness test: The surface smoothness measured under the following condition 1 is 1 to 100 seconds, The surface smoothness determined by the following condition 2 is 15 to 1125 seconds.

1. An adhesive sheet for fixing a polishing pad, comprising: Condition 1: 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.

2. 2. The adhesive sheet for fixing a polishing pad according to claim 1, wherein the average height Rc of the surface irregularities of the adhesive layer A is 10 to 40 μm, and the cutting level difference Rδc of the contour curve is 5 to 25 μm.

3. 3. The adhesive sheet for fixing a polishing pad according to claim 2, wherein the kurtosis Rku of the surface irregularities of the adhesive layer A is less than 3.

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

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

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

7. The surface of the adhesive layer B that is not in contact with the sheet-like substrate is in contact with a release sheet FB, 7. The adhesive sheet for fixing a polishing pad with a release sheet according to claim 6, wherein the material of the release sheet FB is a plastic film that does not contain paper.

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

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

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

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

12. A method for fixing a polishing pad to a platen via an adhesive sheet, comprising peeling off the release sheet FA from the polishing pad having the release sheet and adhesive layer A according to claim 11, and attaching the adhesive layer A to the platen.

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