Pad for chemical mechanical polishing

Abstract

To provide a pad for chemical mechanical polishing which can further reduce contamination of an object to be polished by a zinc component.SOLUTION: A pad 100 for chemical mechanical polishing includes a resin sheet 110 having a polishing surface for polishing an object to be polished or a holding surface for holding the object to be polished, an adhesive layer 120 which is provided on a side opposite to the polishing surface or the holding surface of the resin sheet 110, and fixes the resin sheet 110 to a polishing device, and a release sheet 130 which is provided so as to be joined to the surface opposite to the resin sheet 110 of the adhesive layer 120, and protects the adhesive layer 120, wherein a content of zinc of the release sheet 130 is 3.0 ppm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a chemical mechanical polishing pad used for planarizing semiconductor materials, optical materials, metal materials, ceramic materials, and the like. [Background technology]

[0002] Chemical mechanical polishing (CMP) is commonly performed on semiconductor materials, optical materials, metal materials, ceramic materials, etc. In chemical mechanical polishing, a polishing pad made of a resin such as polyurethane is used to polish the object to be polished, and a holding pad is used to hold the object to be polished. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3906688 Summary of the Invention [Problem to be solved by the invention]

[0004] In particular, in the field of semiconductor materials, when polishing silicon wafers and the like, surface contamination of the polished object due to zinc components can be a problem. Although polishing cloths with a zinc content of 100 ppm or less have been known (Patent Document 1), even when such polishing cloths are used for chemical mechanical polishing, they are insufficient in solving the problem of surface contamination of the polished object.

[0005] On the other hand, chemical mechanical polishing pads typically have an adhesive layer for fixing the pad to a polishing apparatus, and the adhesive layer is further covered with a release sheet (peeling sheet, separator) to protect the surface from dust, dirt, etc. Until now, this release sheet was discarded when the chemical mechanical polishing pad was fixed to the polishing apparatus, and therefore it was thought not to be involved in contaminating the polished object.

[0006] The present invention has been made in view of the above problems, and has an object to provide a chemical mechanical polishing pad that can further reduce contamination of an object to be polished by zinc components. [Means for solving the problem]

[0007] In order to achieve the object of the present invention, the present inventors have conducted extensive research and have surprisingly discovered that the zinc component contained in a release sheet contaminates the object to be polished.The present inventors have also found that the above-mentioned object can be solved by reducing the zinc content of the release sheet or the amount of zinc present on the surface of the release sheet, and have thus completed the present invention.

[0008] That is, the present invention is as follows. [1] A chemical mechanical polishing pad comprising: a resin sheet having a polishing surface for polishing an object to be polished or a holding surface for holding the object to be polished; an adhesive layer for fixing the resin sheet to a polishing device, the adhesive layer being provided on the side of the resin sheet opposite the polishing surface or the holding surface; and a release sheet for protecting the adhesive layer, the release sheet being provided so as to be bonded to the surface of the adhesive layer opposite the resin sheet, wherein the zinc content of the release sheet is 3.0 ppm or less. [2] The chemical mechanical polishing pad described in [1] above, wherein the amount of zinc present on the surface of the release sheet opposite the adhesive layer is 0.05 at% or less when the surface is measured by energy dispersive X-ray spectroscopy. [3] A chemical mechanical polishing pad comprising: a resin sheet having a polishing surface for polishing an object to be polished or a holding surface for holding the object to be polished; an adhesive layer for fixing the resin sheet to a polishing device, the adhesive layer being provided on the side of the resin sheet opposite the polishing surface or the holding surface; and a release sheet for protecting the adhesive layer, the release sheet being provided so as to be bonded to the surface of the adhesive layer opposite the resin sheet; wherein the amount of zinc present on the surface of the release sheet opposite the adhesive layer is 0.05 at% or less when the surface is measured by energy dispersive X-ray spectroscopy. [4] The chemical mechanical polishing pad according to any one of the above [1] to [3], wherein the release sheet is release paper. [5] The chemical mechanical polishing pad according to any one of the above [1] to [3], wherein the resin sheet has a polishing surface for polishing an object to be polished. [6] The chemical mechanical polishing pad according to any one of the above [1] to [3], wherein the resin sheet has a holding surface for holding an object to be polished. [7] A chemical mechanical polishing pad roll body, in which the chemical mechanical polishing pad according to any one of [1] to [5] above is wound into a roll. [8] A chemical mechanical polishing pad laminate, in which a plurality of chemical mechanical polishing pads according to any one of [1] to [5] above are laminated. [9] A method for selecting a chemical mechanical polishing pad, the method comprising: selecting a chemical mechanical polishing pad according to any one of [1] to [5] above from a plurality of chemical mechanical polishing pads each comprising: a resin sheet having a polishing surface for polishing an object to be polished or a holding surface for holding an object to be polished; an adhesive layer for fixing the resin sheet to a polishing device, the adhesive layer being provided on the side opposite the polishing surface or the holding surface of the resin sheet; and a release sheet for protecting the adhesive layer, the release sheet being provided so as to be bonded to the surface of the adhesive layer opposite the resin sheet; by measuring the zinc content of the release sheet or the amount of zinc present on the surface of the release sheet opposite the adhesive layer.

[10] A method for producing a polished product, comprising: step (A) of removing the release sheet from the chemical mechanical polishing pad described in any one of [1] to [5] above to obtain a resin sheet bonded body comprising the resin sheet and the adhesive layer; step (B) of fixing the resin sheet to the polishing device by adhering the adhesive layer of the resin sheet bonded body obtained by step (A) to the platen of the polishing device; and step (C) of holding a polished object with the holding surface of the resin sheet in the polishing device to which the resin sheet is fixed by step (B) and performing chemical mechanical polishing of the polished object, or performing chemical mechanical polishing of the polished object with the polishing surface of the resin sheet. [Effects of the Invention]

[0009] The chemical mechanical polishing pad of the present invention can further reduce contamination of the workpiece with zinc components. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a chemical mechanical polishing pad according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view schematically showing a chemical mechanical polishing pad laminate according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention will be described in detail below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and can be implemented with any modifications within the scope of the claims of the present invention and their equivalents.

[0012] (Chemical mechanical polishing pad) This embodiment provides a chemical mechanical polishing pad. Fig. 1 is a cross-sectional view schematically showing one aspect of a chemical mechanical polishing pad 100 according to this embodiment. As shown in Fig. 1, the chemical mechanical polishing pad 100 of this embodiment includes a resin sheet 110 having a polishing surface for polishing an object to be polished or a holding surface for holding an object to be polished, an adhesive layer 120 provided on the side of the resin sheet 110 opposite the polishing surface or the holding surface for fixing the resin sheet 110 to a polishing apparatus, and a release sheet 130 provided on the surface of the adhesive layer 120 opposite the resin sheet 110 so as to be bonded thereto for protecting the adhesive layer.

[0013] In the first aspect, when the surface of the release sheet of the chemical mechanical polishing pad of this embodiment is measured by energy dispersive X-ray spectroscopy, the amount of zinc present on the surface opposite to the adhesive layer is 0.05 at% or less.In this aspect, when the surface is measured by energy dispersive X-ray spectroscopy, the amount of zinc present on the surface is preferably 0.04 at% or less, more preferably 0.03 at% or less, even more preferably 0.02 at% or less, particularly preferably 0.01 at% or less.The lower limit of the amount of zinc present is preferably as low as possible, and can be, for example, 0 at% or more.

[0014] In a second aspect, the zinc content of the release sheet in the chemical mechanical polishing pad of this embodiment is 3.0 ppm or less. In this aspect, the zinc content of the release sheet is preferably 2.0 ppm or less, more preferably 1.5 ppm or less, even more preferably 1.0 ppm or less, even more preferably 0.5 ppm or less, and particularly preferably 0.3 ppm or less. The lower limit of the zinc content is preferably as low as possible, and can be, for example, 0 ppm or more. The zinc content can be measured using ICP atomic emission spectroscopy and calculated as a ppm value (w / w) based on mass. In this aspect, the amount of zinc present on the surface opposite the adhesive layer of the release sheet, when measured by energy dispersive X-ray spectroscopy, is preferably 0.05 at% or less, more preferably 0.04 at% or less, even more preferably 0.03 at% or less, even more preferably 0.02 at% or less, and particularly preferably 0.01 at% or less. The lower limit of the amount of zinc present on the surface is preferably as low as possible, and can be, for example, 0 at% or more.

[0015] The chemical mechanical polishing pad of this embodiment can further reduce contamination of the workpiece by zinc components.

[0016] Furthermore, by measuring the zinc content of the release sheet or the amount of zinc present on the surface of the release sheet opposite the adhesive layer for a plurality of chemical mechanical polishing pads, it is possible to determine whether or not the release sheet corresponds to the chemical mechanical polishing pad of this embodiment, which satisfies the condition that the zinc content on the surface is 3.0 ppm or less or the amount of zinc present on the surface is 0.05 at% or less. Alternatively, by selecting the chemical mechanical polishing pad of this embodiment, pads that do not correspond to the chemical mechanical polishing pad of this embodiment can be eliminated. This allows the chemical mechanical polishing pad of this embodiment to be used appropriately for chemical mechanical polishing, and further reduces contamination of the polished object by zinc components.

[0017] (resin sheet) The resin sheet is a sheet body having a polishing surface for polishing an object to be polished or a holding surface for holding the object to be polished. The resin sheet is not particularly limited in material or shape as long as it has a polishing surface or a holding surface, and a wide variety of known resin sheets can be used.

[0018] The resin sheet contains a resin material, which is not particularly limited, but includes resin materials used in known polishing pads or holding pads, such as polyurethane resin, epoxy resin, acrylic resin, polyethylene resin, polynorbornene resin, trans-polyisoprene resin, and styrene-butadiene resin.

[0019] The resin sheet may contain an elastic resin material as the resin material. The elastic resin material means a resin material having elasticity. The elasticity means the property of returning to its original shape when deformation caused by an external force is removed.

[0020] The resin sheet may contain one or more other additives as needed, including, but not limited to, foaming agents, catalysts, surfactants, softeners, fillers, antioxidants, antistatic agents, antiaging agents, UV absorbers, hydrophilic agents, hydrophobic agents, colorants (pigments, dyes, etc.), and light stabilizers.

[0021] The resin sheet may be manufactured by a molding method. A block-shaped molded body manufactured by the molding method is sliced ​​into sheets to form the resin sheet. Alternatively, by changing the size of the mold, it is possible to mold resin sheets having a desired thickness one by one without slicing the block-shaped molded body.

[0022] The resin sheet may contain fibrous materials (for example, natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, and semi-synthetic fibers such as acetate). The fibrous materials may be in the form of woven fabric, knitted fabric, or nonwoven fabric.

[0023] The resin sheet may have a foam layer. The foam layer refers to a layer having a resin material and a plurality of bubbles present within the resin material. When the resin sheet has a foam layer, it can absorb the impact that the polished object receives from the polishing pad during polishing. Therefore, the occurrence of polishing scratches on the surface of the polished object due to the impact during polishing tends to be effectively suppressed. The foam layer may be formed by the molding method described above, or may be formed by a wet solidification method. A foam layer formed by a wet solidification method tends to have better retention of the polished object.

[0024] When the resin sheet has a foam layer, the bubbles present in the foam layer are not particularly limited, but include, for example, closed bubbles, where multiple bubbles exist independently, and open bubbles, where multiple bubbles are connected by communicating holes, or a mixture of these. The shape of the bubbles is not particularly limited, but examples include spherical, approximately spherical, flat, and approximately teardrop-shaped. The average bubble diameter of the bubbles is not particularly limited, but can be, for example, 1 μm to 10,000 μm.

[0025] When a foam layer is formed on the polishing surface or holding surface of the resin sheet, the holding surface or polishing surface may have pores. These pores are formed by exposing bubbles in the foam layer to the surface and are formed by slicing or buffing the foam. By forming pores on the holding surface, when the resin sheet is moistened with an appropriate amount of water and pressed against the workpiece, the workpiece can be better held by the adsorption force of the pores in addition to the interaction between the polishing surface and the workpiece surface and the surface tension of the water. By forming pores on the polishing surface, the polishing slurry can be better held, improving polishing performance.

[0026] If necessary, the resin sheet may be subjected to a known deformation treatment such as grinding, grooving, embossing, or hole-making (punching) on ​​the polished surface or holding surface and / or the surface opposite thereto, and may further have a light-transmitting portion formed thereon. There are no particular limitations on the grinding method, and grinding can be performed by a known method. Specific examples include grinding with sandpaper. There are no particular limitations on the shape of the grooves and embossing, and examples include XY lattice shapes, polygonal shapes, concentric circular shapes, and radial shapes, and multiple types may be combined. The holes formed by hole-making may be through-holes.

[0027] The shape of the holding surface or polishing surface of the resin sheet is not particularly limited as long as it is configured to hold or polish an object to be polished, but it may be configured to hold or polish multiple objects to be polished simultaneously. The shape of the resin sheet is not particularly limited, but may be, for example, circular (including approximately circular), rectangular (including approximately rectangular), or strip-shaped.

[0028] The dimensions of the resin sheet are not particularly limited and can be selected appropriately depending on the size of the material to be polished, the polishing conditions, etc., and if the resin sheet is circular, its diameter; if the resin sheet is rectangular, its short side length; and if the resin sheet is strip-shaped, its width can be, for example, 700 mm or more.

[0029] The thickness of the resin sheet is not particularly limited, but may be, for example, 0.1 mm to 10 mm. The thickness of the resin sheet means the distance from the holding surface or polishing surface of the resin sheet to the opposite surface (the surface on the adhesive layer side), and is measured in accordance with Japanese Industrial Standards (JIS-K-6505 (1995)).

[0030] The density (bulk density) of the resin sheet is not particularly limited, but is, for example, 0.10 g / cm at 25°C. 3 ~1.0g / cm 3 The density can be adjusted, for example, by selecting the type of resin or, when a foam is used, by controlling the amount of bubbles contained in the foam. The density can be measured in accordance with JIS-K-7222 (2005).

[0031] The hardness of the resin sheet is not particularly limited, but may be, for example, a Shore A hardness of 20 to 100 degrees. The hardness of the resin sheet is not particularly limited, but can be adjusted, for example, by selecting the type of resin or, when a foam is used, by controlling the amount of bubbles contained in the foam. The Shore A hardness can be measured in accordance with JIS-K-6253 (2012).

[0032] The compressibility of the resin sheet is not particularly limited, but may be, for example, 0.10% to 60%. The compressive modulus of the resin sheet is not particularly limited, but may be, for example, 60% to 100%. The compressibility and compressive modulus can be determined in accordance with the Japanese Industrial Standards (JIS-L-1021 (2020)) using a Schopper-type thickness gauge (pressure surface: circular with a diameter of 1 cm).

[0033] (Adhesive layer) The adhesive layer is a layered body provided between the resin sheet and the release sheet on the side opposite the polishing surface or holding surface of the resin sheet, for fixing the resin sheet to the polishing device. The adhesive layer is fixed directly or indirectly to the resin sheet. The adhesive layer is not particularly limited in material or shape, and a wide variety of known adhesive layers can be used, as long as it has the adhesive strength to fix the resin sheet to the polishing device. The adhesive layer can be, for example, a double-sided tape layer formed by applying an adhesive to both sides of the substrate, an adhesive layer consisting only of an adhesive, an adhesive processed layer formed by processing the surface of the resin sheet into a seal, or a combination thereof. For peeling prevention and ease of handling, the adhesive layer preferably includes a double-sided tape layer.

[0034] The substrate of the double-sided tape layer is not particularly limited, and may be, for example, a resin substrate containing one or more resins selected from the group consisting of polyimide resins, polyester resins, polyurethane resins, polyethylene resins, polypropylene resins, cellulose resins, polyvinyl chloride resins, polyvinylidene chloride resins, polyvinyl alcohol resins, ethylene-vinyl acetate copolymer resins, polystyrene resins, polycarbonate resins, and acrylic resins.

[0035] The adhesive is not particularly limited and can be arbitrarily selected from adhesives known in the art. The adhesive may be a pressure-sensitive adhesive or a hot-melt adhesive (heat-sensitive adhesive). Examples of pressure-sensitive adhesives include silicone resins, modified silicone resins, acrylic resins, and synthetic rubber resins. Examples of hot-melt adhesives include thermoplastic resins such as acrylic resins, ethylene vinyl acetate resins, olefin resins, synthetic rubber resins, polyamide resins, and polyester resins. From the viewpoints of ease of handling and suppressing deterioration and warping of the resin sheet due to heating, a double-sided tape in which a pressure-sensitive adhesive is provided on both sides of a substrate is preferred.

[0036] (middle class) The adhesive layer and the resin sheet may be in direct contact with each other, or an intermediate layer may be formed between the adhesive layer and the resin sheet. The intermediate layer may be, but is not limited to, a rigid support layer for supporting the chemical mechanical polishing pad, a flexible cushion layer, or the like.

[0037] As the material for the intermediate layer, any of known materials such as nonwoven fabric, resin-impregnated nonwoven fabric, resin film, resin foam sheet, metal foil such as aluminum foil or copper foil can be used.

[0038] The intermediate layer may have a single layer structure or a multi-layer structure made up of multiple layers. There are no particular limitations on the thickness of the intermediate layer, but it may be, for example, 0.1 mm to 10 mm.

[0039] (Release sheet) The release sheet is a layered body provided on the surface of the adhesive layer opposite the resin sheet so as to be bonded thereto for protecting the adhesive layer. The adhesive layer and the release sheet can be peeled off by known means. The release sheet is peeled off and removed before the resin sheet is fixed to the polishing device. Examples of the release sheet include release paper and release film. Among these, release paper is preferred from the viewpoints of availability, processability, and ease of handling by workers. As the release sheet, a release sheet having a zinc content of 3.0 ppm or less, or having a zinc content of 0.05 at% or less on the surface opposite the adhesive layer when the surface is measured by energy dispersive X-ray spectroscopy, can be used.

[0040] The material of the release sheet is not particularly limited, and materials known in the art can be used. The thickness of the release sheet is not particularly limited, but can be, for example, 10 μm to 1000 μm. A release agent may be applied to the adhesive layer side of the release sheet.

[0041] Conventional release sheets have a zinc content of more than 3.0 ppm and a surface zinc content of more than 0.05 at% due to the use of zinc-containing materials, zinc-based catalysts, etc. in their manufacturing process. Release sheets that meet the conditions of a zinc content of 3.0 ppm or less or a surface zinc content of 0.05 at% or less can be produced by using or coating with a material that does not contain or has a reduced zinc content at the contact points with the release sheet or its manufacturing intermediate in the release sheet manufacturing equipment, by not using zinc-containing materials or zinc-based catalysts, etc., or by undergoing a known refining process or metal removal process. It is also possible to prevent zinc from penetrating the release sheet and reduce the zinc content of the release sheet by using zinc-free synthetic materials instead of natural materials as release agents and adhesives.

[0042] (Frame material) When the resin sheet has a holding surface, the holding surface of the resin sheet may be provided with a frame material to prevent the workpiece from falling off. The frame material is provided, for example, on the peripheral surface of the holding surface of the resin sheet. The frame material may have one or more holding holes for accommodating the workpiece. By providing the frame material, the range of lateral displacement is restricted, so that the workpiece can be prevented from shifting laterally during polishing and falling off the holding surface. An adhesive may be used to fix the frame material to the holding surface of the resin sheet.

[0043] (Product form) The chemical mechanical polishing pad of this embodiment can be transported or stored as a chemical mechanical polishing pad roll body in a rolled form, a chemical mechanical polishing pad laminate in a laminated form, or the like.

[0044] The chemical mechanical polishing pad roll body or chemical mechanical polishing pad laminate may be in a form in which the surface of the release sheet opposite the adhesive layer is in contact with the polishing surface or holding surface of the resin sheet.

[0045] 2 is a cross-sectional view schematically illustrating one embodiment of the above-described chemical mechanical polishing pad laminate 200. During transportation or storage, the above-described chemical mechanical polishing pad laminate 200 is stacked such that the surface of the resin sheet 110 opposite the adhesive layer 120, i.e., the polishing surface or holding surface, directly contacts the surface of the release sheet 130 opposite the adhesive layer 120, as shown in FIG.

[0046] Similarly, the chemical mechanical polishing pad roll body having the above-described configuration is wound into a roll shape during transportation or storage so that the surface of the release sheet opposite the adhesive layer comes into direct contact with the polishing surface or holding surface of the resin sheet.

[0047] In conventional chemical mechanical polishing pads, the zinc content of the release sheet or the amount of zinc present on the surface was high, and therefore, due to the contact as described above and / or the contact between the surface of the release sheet opposite the adhesive layer of the semi-finished product stacked or wound into a roll during the production process of the chemical mechanical polishing pad and the polishing surface or holding surface of the resin sheet, the zinc contained in the release sheet may contaminate the polishing surface or holding surface, and ultimately result in contamination of the object to be polished. On the other hand, in the chemical mechanical polishing pad roll body and chemical mechanical polishing pad laminate of this embodiment, the zinc content of the release sheet or the amount of zinc present on the surface of the release sheet is within the above-mentioned range, and therefore contamination of the object to be polished can be suppressed even when the contact as described above occurs.

[0048] (Method of manufacturing polished products) In the production of a polished product, polishing the polished product using the chemical mechanical polishing pad of this embodiment can further reduce contamination of the polished product by zinc components. This embodiment provides a method for producing a polished product using the chemical mechanical polishing pad of this embodiment. The method for producing a polished product of this embodiment includes the following steps: (A) removing the release sheet from the chemical mechanical polishing pad of this embodiment to obtain a resin sheet bonded body comprising a resin sheet and an adhesive layer; (B) attaching the adhesive layer of the resin sheet bonded body obtained in step (A) to the platen of a polishing device to fix the resin sheet to the polishing device; and (C) using the polishing device to which the resin sheet is fixed in step (B) to hold the polished product on the holding surface of the resin sheet and perform chemical mechanical polishing of the polished product, or to perform chemical mechanical polishing of the polished product on the polishing surface of the resin sheet. By using the method for producing a polished product of this embodiment, contamination of the polished product by zinc components can further be reduced. This method for producing a polished product may include known steps other than those described above, as long as the chemical mechanical polishing pad of this embodiment is used as the chemical mechanical polishing pad.

[0049] In the method for producing a polished product of this embodiment, when using a chemical mechanical polishing pad of this embodiment equipped with a resin sheet having a polishing surface, in step (A), the release sheet is removed from the chemical mechanical polishing pad to obtain a resin sheet bonded body equipped with a resin sheet having a polishing surface and an adhesive layer; in step (B), the adhesive layer of the resin sheet bonded body is bonded to the polishing table of a polishing device, thereby fixing the resin sheet having a polishing surface to the polishing device; in step (C), the polishing surface of the resin sheet is used to perform chemical mechanical polishing of the polished object. In this case, in step (B), as described above, a resin sheet having a polishing surface is fixed to the polishing device, while another resin sheet having a holding surface is fixed to the polishing device; in step (C), the polishing device uses the holding surface to hold the polished object, and chemical mechanical polishing of the polished object is performed by the polishing surface.

[0050] In the method for producing a polished workpiece of this embodiment, when using a chemical mechanical polishing pad of this embodiment equipped with a resin sheet having a holding surface, in step (A), the release sheet is removed from the chemical mechanical polishing pad to obtain a resin sheet bonded body equipped with a resin sheet having a holding surface and an adhesive layer; in step (B), the adhesive layer of the resin sheet bonded body is bonded to the holding surface plate of a polishing device, thereby fixing the resin sheet having a holding surface to the polishing device; in step (C), the polishing device holds the polished object with the holding surface of the resin sheet to perform chemical mechanical polishing of the polished object. In this case, in step (B), as described above, the resin sheet having a holding surface is fixed to the polishing device, while another resin sheet having a polishing surface is fixed to the polishing device; in step (C), the polishing device holds the polished object with the holding surface and performs chemical mechanical polishing of the polished object with the polishing surface.

[0051] In the method for manufacturing the polished workpiece of this embodiment, both a chemical mechanical polishing pad of this embodiment having a resin sheet with a polishing surface and a chemical mechanical polishing pad of this embodiment having a resin sheet with a support surface may be used simultaneously.

[0052] In step (A), the method for removing the release sheet from the chemical mechanical polishing pad is not particularly limited, and any known method can be used.

[0053] The chemical mechanical polishing in step (C) may be primary polishing (rough polishing), finish polishing, or a combination of both.

[0054] In step (C), while supplying the polishing slurry, the holding platen and the polishing platen are rotated relative to each other while pressing the workpiece from the holding surface side of the holding platen to the polishing surface side, so that the polishing surface performs chemical mechanical polishing on the processed surface of the workpiece. The holding platen and the polishing platen may rotate in the same direction at different rotation speeds, or may rotate in different directions. Furthermore, the workpiece may be polished while moving (rotating) inside the frame during the polishing process.

[0055] The polishing slurry may contain water, an oxidizing agent such as hydrogen peroxide, chemical components such as acid components and alkaline components, additives, and abrasive grains (abrasive particles; for example, SiC, SiO2, Al2O3, and CeO2), depending on the object to be polished and the polishing conditions.

[0056] The object to be polished is not particularly limited, but examples thereof include optical materials such as lenses, plane-parallel plates, and reflecting mirrors, semiconductor wafers, semiconductor devices, hard disk substrates, metals, and ceramic materials. From the viewpoint of the need to highly prevent contamination by zinc components, the object to be polished is preferably a semiconductor material such as a semiconductor wafer or semiconductor device, and more preferably a silicon wafer, as this tends to provide the effects of the present invention more effectively. [Example]

[0057] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to these examples. Unless otherwise specified, the temperature conditions are room temperature (25°C), and unless otherwise specified, the pressure conditions are atmospheric pressure (1 atm).

[0058] Example 1 A double-sided tape was prepared for forming the adhesive layer. The adhesive layer consisted of a PET substrate with a pressure-sensitive adhesive primarily composed of acrylic synthetic rubber applied to both sides. The surface to be bonded to the resin sheet was coated with a release film, and the opposite surface was coated with a release paper manufactured without using zinc-containing materials. The release film was peeled off from the double-sided tape to expose the adhesive surface with the pressure-sensitive adhesive. The exposed adhesive surface of the double-sided tape was bonded to the opposite side of the polishing surface of a Fujibo Ehime polishing pad (product name: DF4300) (a resin sheet with an abrasive surface) under pressure, and the pad was wound up into a roll with the polishing surface and release paper in contact. The resin sheet was then cut into a circular shape to produce a resin sheet with release paper (a chemical mechanical polishing pad). The resulting resin sheet with release paper was packaged in a laminated state with the abrasive layer and release paper in contact for transportation and storage.

[0059] (Comparative Example 1) A resin sheet with release paper was produced by carrying out the double-sided tape attachment step in the same manner as in Example 1, except that a pressure-sensitive adhesive primarily containing natural rubber was used instead of a pressure-sensitive adhesive primarily containing acrylic synthetic rubber, and double-sided tape covered with release paper containing a predetermined amount of zinc was used as the release paper, and the resin sheet was wound into a roll and packaged in a stacked state in the same manner as in Example 1.

[0060] (Reference Examples 1 and 2) Two types of double-sided tape were prepared, each having a pressure-sensitive adhesive primarily composed of acrylic synthetic rubber applied to both sides of a PET substrate, one side of which was covered with a release film, and the other side of which was covered with release paper (different from that used in Example 1) that was manufactured without using a material containing zinc. The two types of double-sided tape used different release papers.

[0061] (Test Example 1: Measurement of zinc content in release paper) The zinc content (ppm (μg / g)) of the release paper of the double-sided tapes used in Example 1 and Comparative Example 1 and the release paper of the double-sided tapes prepared in Reference Examples 1 and 2 was measured by ICP atomic emission spectroscopy. Specifically, approximately 0.5 g of the release paper sample was weighed out and subjected to acid decomposition at 230°C for 39 min (1 hr including heating) with 21.3 g of 70% nitric acid in a microwave sample pretreatment device. Because insoluble matter was observed during this acid decomposition, an additional 7.1 g of nitric acid was added and subjected to additional acid decomposition at 230°C for 39 min (1 hr including heating). The acid decomposed sample was cooled, filtered through a filter paper, and diluted to 50 ml with pure water to prepare a sample. To determine the solid content remaining on the filter paper, the filter paper used in the acid decomposition was placed in a platinum crucible and heated at 550°C for 2 hours to remove organic matter from the filter paper. After cooling, 0.1 g of lithium tetraborate was added to the crucible, mixed gently, and heated in a microwave pretreatment device at 950 °C for 10 minutes for alkali fusion. The transparent, solidified sample was redissolved in 1N nitric acid while heating, and the solution was diluted to 50 ml while filtering through filter paper to obtain a sample. Each of the obtained samples was subjected to an ICP emission spectrometer, and the zinc content in the release paper sample was calculated from the obtained measurement values. The device used was an Optima 2100DV manufactured by Perkin Elmer. The zinc content of the release paper was 0.2 ppm in Example 1, 7.6 ppm in Comparative Example 1, <0.01 ppm in Reference Example 1, and 0.7 ppm in Reference Example 2.

[0062] (Test Example 2: Measurement of the amount of zinc present on the surface of release paper) The amount of zinc present (at% (atom count / atom count%)) was measured by EDS (energy dispersive X-ray spectroscopy) on the surface opposite the double-sided tape of the release paper of the double-sided tape used in Example 1 and the release paper of the double-sided tape used in Comparative Example 1. Specifically, the amount of zinc present on the release paper surface was calculated using an EDS analyzer under the following conditions: acceleration voltage: 20 kV, backscattered electron image, vacuum degree: 35 Pa (low vacuum mode), and observation magnification: 100x. The measurement device used was a JSM-IT100 manufactured by JEOL Ltd. Zinc was not detected on the release paper surface of Example 1 (below the detection limit of 0.01 at%), but zinc was detected at 0.10 at% on the release paper surface of Comparative Example 1.

[0063] (Test Example 3: Contamination Evaluation A of Polishing Layer) The zinc content of the polished surface (i.e., the surface opposite the adhesive layer) of the resin sheet with release paper prepared in Example 1 and the resin sheet with release paper prepared in Comparative Example 1 was measured using laser ablation ICP mass spectrometry (LA-ICP-MS). Specifically, the polished surface and five points excavated by laser at 10 μm intervals up to 40 μm were measured at three points (n number) for a total of 15 points on the test piece of the resin sheet with release paper, and the measured zinc content was calculated by averaging the obtained zinc elemental content in ppm (g / μg). A Thermo Fisher Juno solid nebulizer was used. As a result, the zinc content of the polished surface of the resin sheet of Comparative Example 1 was 35.5 ppm, while that of Example 1 was 25.2 ppm. This confirmed that the transfer of zinc from the release paper to the polished surface of the resin sheet with release paper of Example 1 was suppressed compared to Comparative Example 1.

[0064] (Test Example 4: Evaluation of contamination on silicon wafers after polishing test) Silicon wafers were polished using the resin sheet with release paper prepared in Example 1 and the resin sheet with release paper prepared in Comparative Example 1. Lifetime measurement was performed on the polished silicon wafers using the μPCD method (microwave photoconductivity decay method). Compared to when the resin sheet with release paper prepared in Comparative Example 1 was used, when the resin sheet with release paper prepared in Example 1 was used, metal contamination of the silicon wafer was significantly reduced, especially in the early stages of polishing.

[0065] (Test Example 5: Contamination Evaluation B of Polishing Layer) The release paper from the double-sided tape used in Example 1 and Comparative Example 1, as well as the release paper from the double-sided tape prepared in Reference Examples 1 and 2, was cut into 20 cm square pieces to prepare release paper pieces. A polyurethane resin sheet (product name: WP3003) manufactured by Fujibo Ehime Co., Ltd. was cut into 10 cm square pieces. The surface of the release paper sample opposite the adhesive layer was rubbed against the entire surface of the resin sheet piece for 1 minute to obtain a resin sheet sample. For comparison, a resin sheet sample without the release paper was also prepared as a control sample. The zinc content (ppm (μg / g)) on the surface of the resin sheet sample was then measured using ICP atomic emission spectroscopy. Specifically, approximately 0.5 g of resin sample was weighed from the center surface of the resin sheet sample and subjected to acid decomposition with 21.3 g of 70% nitric acid at 230°C for 39 min (1 hour including heating) in a microwave sample pretreatment device. Because insoluble matter was observed during this acid digestion, an additional 7.1 g of nitric acid was added and further acid digestion was performed at 230°C for 39 min (1 h including heating). The acid-digested sample was cooled, filtered through filter paper, and then diluted to 50 ml with pure water to prepare the sample. The filter paper used in the acid digestion was placed in a platinum crucible and heated at 550°C for 2 hours to remove any remaining solids. After cooling, 0.1 g of lithium tetraborate was added to the crucible, gently mixed, and heated to 950°C for 10 min in a microwave pretreatment device for alkali fusion. The transparent, solidified sample was redissolved in 1N nitric acid while heating, filtered through filter paper, and then diluted to 50 ml to prepare the sample. The resulting samples were each subjected to an ICP atomic emission spectrometer, and the zinc content in the resin sample was calculated from the measured values. The instrument used was a Perkin-Elmer Avio 550 Max. The results of Test Example 1 and Test Example 5 are summarized in Table 1.

[0066] [Table 1]

[0067] The resin sheet surface contacted with the release paper of Example 1 and Reference Examples 1 and 2 did not have a significant difference in zinc content compared with the uncontacted control sample.On the other hand, the resin sheet surface contacted with the release paper with a higher zinc content of Comparative Example 1 had an increase in zinc content of about 0.6 ppm.Therefore, a chemical mechanical polishing pad with a release paper having a zinc content of less than a predetermined value may be able to easily prevent zinc from adhering to the resin sheet surface during manufacturing, transportation, storage, etc., and may be able to prevent the release paper from having an adverse effect on polishing even though it does not have the opportunity to come into contact with the polished object or polishing slurry.

[0068] From the results of Test Examples 1 to 5, it is believed that the chemical mechanical polishing pad of the present invention can reduce zinc contamination of the polished object compared to conventional chemical mechanical polishing pads. [Explanation of symbols]

[0069] 100 Chemical mechanical polishing pad 110 Resin sheet 120 Adhesive layer 130 Release sheet 200 Chemical mechanical polishing pad laminate

Claims

1. a resin sheet having a polishing surface for polishing an object to be polished or a holding surface for holding an object to be polished; an adhesive layer provided on the opposite side of the resin sheet to the polishing surface or the holding surface for fixing the resin sheet to a polishing apparatus; a release sheet for protecting the adhesive layer, the release sheet being provided so as to be bonded to a surface of the adhesive layer opposite to the resin sheet; A chemical mechanical polishing pad comprising: The chemical mechanical polishing pad, wherein the release sheet has a zinc content of 3.0 ppm or less.

2. 2. The chemical mechanical polishing pad of claim 1, wherein the amount of zinc present on the surface of the release sheet opposite the adhesive layer is 0.05 at% or less when the surface is measured by energy dispersive X-ray spectroscopy.

3. a resin sheet having a polishing surface for polishing an object to be polished or a holding surface for holding an object to be polished; an adhesive layer provided on the opposite side of the resin sheet to the polishing surface or the holding surface for fixing the resin sheet to a polishing apparatus; a release sheet for protecting the adhesive layer, the release sheet being provided so as to be bonded to a surface of the adhesive layer opposite to the resin sheet; A chemical mechanical polishing pad comprising: A chemical mechanical polishing pad, wherein the amount of zinc present on the surface of the release sheet opposite the adhesive layer is 0.05 at % or less when the surface is measured by energy dispersive X-ray spectroscopy.

4. The chemical mechanical polishing pad according to claim 1 or 3, wherein the release sheet is release paper.

5. 4. The chemical mechanical polishing pad according to claim 1, wherein the resin sheet has a polishing surface for polishing an object to be polished.

6. 4. The chemical mechanical polishing pad according to claim 1, wherein the resin sheet has a holding surface for holding an object to be polished.

7. A chemical mechanical polishing pad roll body, comprising the chemical mechanical polishing pad according to any one of claims 1 to 3 wound into a roll.

8. A chemical mechanical polishing pad laminate, in which a plurality of chemical mechanical polishing pads according to any one of claims 1 to 3 are laminated.

9. a resin sheet having a polishing surface for polishing an object to be polished or a holding surface for holding an object to be polished; an adhesive layer provided on the opposite side of the resin sheet to the polishing surface or the holding surface for fixing the resin sheet to a polishing apparatus; a release sheet for protecting the adhesive layer, the release sheet being provided so as to be bonded to a surface of the adhesive layer opposite to the resin sheet; From among a plurality of chemical mechanical polishing pads comprising: By measuring the zinc content of the release sheet or the amount of zinc present on the surface of the release sheet opposite to the adhesive layer, A method for selecting a chemical mechanical polishing pad, comprising selecting the chemical mechanical polishing pad according to any one of claims 1 to 3.

10. A step (A) of removing the release sheet from the chemical mechanical polishing pad according to any one of claims 1 to 3 to obtain a resin sheet bonded body comprising the resin sheet and the adhesive layer; a step (B) of fixing the resin sheet to the polishing apparatus by adhering the adhesive layer of the resin sheet bonded body obtained in the step (A) to a surface plate of the polishing apparatus; In the polishing apparatus to which the resin sheet is fixed in the step (B), a step (C) is performed in which a polished object is held by the holding surface of the resin sheet and chemical mechanical polishing of the polished object is performed, or chemical mechanical polishing of the polished object is performed by the polishing surface of the resin sheet; A method for manufacturing a polished workpiece, comprising:

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